text:
|Publication number
|Publication type
|Application number
|Publication date
|Mar 18, 2003
|Filing date
|Apr 17, 2001
|Priority date
|Oct 24, 1997
|Fee status
|Also published as
|Publication number
|Chung J. Lee, Hui Wang, Giovanni Antonio Foggiato
|Original Assignee
|Quester Technology, Inc.
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (42), Non-Patent Citations (33), Referenced by (20), Classifications (54), Legal Events (5)
|External Links: USPTO, USPTO Assignment, Espacenet
This application is a divisional of Ser. No. 09/440,297 filed Nov. 15, 1999, now U.S. Pat. No. 6,248,407, which is a divisional of Ser. No. 08/957,481, filed Oct. 24, 1997, now U.S. Pat. No. 6,020,458, issued Feb. 1, 2000.
Lee et al., Chemicals and Processes for Making Fluorinated Poly(Para-Xylylenes). Attorney Docket No.: QTII 8021 SRM/DBB.
Lee et al., New Deposition Systems and Processes for Transport Polymerization and Chemical Vapor Deposition. Attorney Docket No.: QTII 8022 SRM/DBB.
Lee et al., Low Dielectric Constant Materials with Improved Thermal and Mechanical Properties. Attorney Docket No.: QTII 8023 SRM/DBB.
Lee et al., Low Dielectric Constant Materials Prepared from Photon or Plasma Assisted Chemical Vapor Deposition and Transport Polymerization of Selected Compounds. Attorney Docket No.: QTII 8024 SRM/DBB.
All of the above co-pending applications are herein incorporated fully by reference.
This invention relates to the precursors for manufacturing dielectric materials with low dielectric constants for use in the manufacture of semiconductor integrated circuits. The invention also relates to the polymers made from these precursors, the processes used to make polymers, and the integrated circuits made from these polymers.
As integrated circuits (ICs) have become progressively more microminiaturized to provide higher computing speeds, the low dielectric constant polymers used in the manufacturing of the ICs have proven to be inadequate in several ways. Specifically, they have not had sufficient thermal stability, generate toxic byproducts, are inefficient to manufacture, and the dielectric constants are too high.
During the past few years, several types of precursors have been used to manufacture polymers with low dielectric constants for use in manufacture of integrated circuits (IC). Transport Polymerization (TP) and Chemical Vapor Deposition (CVD) methods have been used to deposit low dielectric materials. The starting materials, precursors and end products fall into three groups, based on their chemical compositions. The following examples of these types of precursors and products are taken from Proceedings of the Third International Dielectrics for Ultra Large Scale Integration Multilevel Interconnect Conference (DUMIC), Feb. 10-11 (1997).
I. Modification of SiO2 by Carbon (C) and Fluorine (F)
The first method described is the modification of SiO2 by adding carbon and/or fluorine atoms. McClatchie et al., Proc. 3d Int. DUMIC Conference, 34-40 (1997) used methyl silane (CH3—SiH3) as a carbon source, and when reacted with SiH4 and the oxidant H2O2 and deposited using a thermal CVD process, the dielectric constant (K) of the resulting polymer was 3.0. However, this K is too high to be suitable for the efficient miniaturization of integrated circuits.
Sugahara et al., Proc. 3d Int. DUMIC Conference, 19-25 (1997) deposited the aromatic precursor, C6H5—Si—(0CH3)3 on SiO2 using a plasma enhanced (PE) CVD process that produced a thin film with a dielectric constant K of 3.1. The resulting polymer had only a fair thermal stability (0.9% weight loss at 450� C. in 30 minutes under nitrogen). However, the 30 min heating period is shorter than the time needed to manufacture complex integrated circuits. Multiple deposition steps, annealing, and metalizing steps significantly increase the time during which a wafer is exposed to high temperatures. Thus, this dielectric material is unsuitable for manufacture of multilevel integrated circuits.
Shimogaki et al., Proc. 3Int. DUMIC Conference, 189-196 (1997) modified SiO2 using CF4 and SiH4 with NO2 as oxidant in a PECVD process. The process resulted in a polymer with a dielectric constant of 2.6, which is lower than that of SiO2.
However, one would expect low thermal stability due to low bonding energy of sp3C—F and sp3C—Si bonds (BE=110 and 72 kcal/mol., respectively) in the film. The low thermal stability would result in films which could not withstand the long periods at high temperatures necessary for integrated circuit manufacture.
II. Amorphous-Carbon (αC)- and Fluorinated Amorphous Carbon (F-αC)-Containing Low Dielectric Materials
The second approach described involves the manufacture of α-carbon and α-fluorinated carbon films. Robles et al., Proc. 3d Int. DUMIC Conference, 26-33 (1997) used various combinations of carbon sources including methane, octafluorocyclobutane and acetylene with fluorine sources including C2F6 and nitrogen trifluoride (NF3) to deposit thin films using a high density plasma (HDP) CVD process.
The fluorinated amorphous carbon products had dielectric constants as low as 2.2 but had very poor thermal stability. These materials shrank as much as 45% after annealing at 350� C. for 30 minutes in nitrogen.
One theory which could account for the low thermal stability of the fluorinated amorphous carbon products is the presence of large numbers of sp3C—F and sp3C—sp3C bonds in the polymers. These bonds have a bonding energy of 92 kcal/mol. Thus, the films can not withstand the long periods of high temperatures necessary for IC manufacture.
III. Fluorinated Polymers
The third approach described uses fluorinated polymers. Kudo et al., Proc. 3d Int. DUMIC Conference, 85-92 (1997) disclosed polymers made from C4F8 and C2H2 with a dielectric constant of 2.4. The polymers had a Tg of 450� C. (Kudo et al., Advanced Metalization and Interconnect Systems for ULSI Applications; Japan Session, 71-75 (1996)).
However, despite its low leakage current due to presence of sp3C—F bonds, a low thermal stability can be expected due to presence of sp3C—F and sp3C—sp3C bonds in the films. Thus, like the F-αC-containing polymers discussed above, these fluorinated polymers are unable to withstand the prolonged high temperatures necessary for IC manufacture.
LaBelle et al, Proc. 3d Int. DUMIC Conference, 98-105 (1997) made CF3—CF(O)—CF2 polymers using a pulsed plasma CVD process, which resulted in a polymer film with a dielectric constant of 1.95. However, in spite of the low K, these polymer films would be expected to have low thermal stability due to presence of sp3C—sp3C and sp3C—O bonds in these films which have bonding energies of 85 kcal/mol.
Therefore, none of the previously described low dielectric materials have suitably low K and high thermal stability necessary for IC manufacturing.
Wary et al, (Semiconductor International, June 1996, 211-216) used the precursor, (α, α, α1, α1) tetrafluoro-di-p-xylylene) or {—CF2—C6H4—CF2—}2 Parylene AF-4™, which contains a non-fluorinated aromatic moiety, and a thermal CVD process to manufacture Parylene AF-4™ which has the structural formula: {—CF2—C6H4—CF2—})n. Films made from Parylene AF-4™ have a dielectric constant of 2.28 and have increased thermal stability compared to the above-mentioned dielectric materials. Under nitrogen atmosphere, a polymer made of Parylene AF-4™ lost only 0.8% of its weight over 3 hours at 450� C.
However, in spite of the advantages of conventional poly(para-xylylenes), there are disadvantages of the known methods of their manufacture. First, the manufacture of their precursors is inefficient because the chemical reactions have low yields, and the process is expensive and produces toxic byproducts. Further, it is difficult to eliminate redimerization of the reactive intermediates. When deposited along with polymers, these dimers decrease the thermal stability and mechanical strength of the film.
Thus, the prior art contains no examples of dielectric material precursors for semiconductor manufacture which have desired properties of low dielectric constant, high thermal stability, and low cost.
The present invention is directed to overcoming the disadvantages of the prior art.
Accordingly, one object of the invention is to provide precursor materials which can be used to manufacture products including polymers with low dielectric constants for IC manufacture.
Another object of the invention is to provide precursors which can be manufactured into products which have high thermal stability.
Yet another object of the invention is to provide precursors which can be polymerized as thin layers on a substrate.
An additional object of the invention is to provide precursor materials which are inexpensive.
A further object is to provide materials which can be made into products with high efficiency.
An additional object of the invention is to provide precursors which can be made into dielectric materials which can be easily and accurately shaped after manufacture.
The invention includes novel precursors containing a fluorinated silane, a fluorinated siloxane or a fluorocarbon each containing a fluorinated aromatic moiety. The precursors are suitable for making polymers with low dielectric constants and high thermal stability. The polymers can be used for making integrated circuits.
Additionally, the invention includes methods for making polymers for integrated circuit manufacture using novel fluorinated silanes, fluorinated siloxanes, or fluorocarbons, each containing a fluorinated aromatic moiety.
Furthermore, the invention includes integrated circuits comprising low dielectric constant polymers made using fluorinated silanes, fluorinated siloxanes, or fluorocarbons, each containing a fluorinated aromatic moiety.
Accordingly, one aspect of the invention comprises precursors for using in manufacturing polymers with low dielectric constants which are useful in the manufacture of integrated circuits (ICs).
Another aspect of the invention comprises precursors for use in manufacturing polymers with high thermal stability which are useful in the manufacture of ICs.
Another aspect of the invention comprises methods for reacting the precursors and depositing them as thin films on substrates for IC manufacture.
Yet another aspect of the invention comprises the deposited thin film made using the novel precursors and methods for their reaction and deposition.
Another aspect of the invention is the integrated circuits comprised of thin films derived through the reaction and deposition of the novel precursors.
Other objects, aspects and advantages of the invention can be ascertained from the review of the additional detailed disclosure, the examples, the figures and the claims.
FIG. 1. Embodiment of an apparatus of this invention used for thermolytic transport polymerization of fluorinated silanes, fluorinated siloxanes, and fluorocarbons.
FIG. 2. Embodiment of an apparatus of this invention used for radio frequency plasma enhanced transport polymerization of fluorinated silanes, fluorinated siloxanes, and fluorocarbons.
FIG. 3. Embodiment of an apparatus of this invention used for high density plasma enhanced chemical vapor deposition of fluorinated silanes, fluorinated siloxanes, and fluorocarbons.
FIG. 4. Embodiment of an apparatus of this invention used for photon assisted transport polymerization of fluorinated silanes, fluorinated siloxanes, and fluorocarbons.
FIG. 5. Embodiment of a universal deposition system of this invention for deposition of fluorinated silanes, fluorinated siloxanes, and fluorocarbons.
FIG. 6. Schematic cross-section view of a thin film of this invention made of polymers derived from fluorinated silanes, fluorinated siloxanes, and fluorocarbons.
I. Precursors for Making Fluorinated Materials With Low Dielectric Constant
This invention discloses novel precursors for making three categories of fluorine-containing low dielectric materials. These precursors include fluorinated silanes, fluorinated siloxanes, and fluorocarbons. The dielectric materials are useful in the manufacture of semiconductors for integrated circuits and other electronic devices. Manufacture of smaller and faster integrated circuits requires intermetal dielectric (IMD) and interlevel dielectric (ILD) materials which minimize the communication of electrical signals between adjacent conductive lines, referred to as the interconnects. Low dielectric materials are useful to minimize this "cross-talk" within and between layers of integrated circuits.
The polymers prepared from the precursors of the present invention are rigid and contain a high degree of substitution of hydrogen atoms by fluorine atoms. In these polymers, the fluorine in the aromatic ring provides the low dielectric constant (K) below about 0.3 and molecular rigidity. This rigidity is reflected by high glass transition temperature (Tg) temperature of decomposition above about 300� C., high elastic modulus (E) and high shear modulus (G). The elastic modulus is above about 2, and preferably is about 3.
One theory for the thermal stability of the poly(para-xylylenes) is that the higher bonding energies of the sp2C═sp2C, sp2C—H and sp2C—sp3C bonds of 145, 111 and 102 kcal/mol. respectively. In addition, the sp3C—F bonds may also be involved in hyperconjugation with sp2C═sp2C double bonds of the adjacent phenylene groups in Parylene AF-4™. This hyperconjugation renders a higher bond energy for the sp3C—F bonds than that found in non-hyperconjugated sp3C- bonds. (See A. Streitwiesser et al., Introduction to Organic Chemistry, Appendix II, University of California Press, Berkeley, Calif. (1992)) (Table 1).
Energies of Carbon Bonds In Dielectric Polymers
Bond Type:
Bond Energy
Bond Type:
Bond Energy
Thus, carbon atoms bonded to other atoms by with sp2C═sp2C, sp2C—F and hyperconjugated sp3C—F bonds confer advantages to polymers containing them, whereas other types of bonds (such as sp3C—H and sp3C—C bonds) do not confer these advantages. The sp2C=sp2C and other sp2C bonds increase the mechanical strength and increase Td of the polymer. The presence of fluorine atoms in the aromatic moieties of the polymers of this invention decreases the dielectric constant, and the sp2C—F and hyperconjugated sp3C—F bonds confer greater thermal stability to a polymer containing them. In contrast, polymers which do not contain these types of bonds have lower thermal stability and higher dielectric constant. As one can see from Table 1, although precursors containing sp2C=sp2C bonds have high thermal stability (bond energy=145 kcal/mol), it is not desirable to use any non-fluorinated compound that consists of these chemical bonds as starting material. Using these non-fluorinated compounds as starting material for PECVD will result in high thermal stability, however, the resulting polymer will also have an high dielectric constant (K>2.5). Therefore, materials with low dielectric constants, high elastic and shear moduli (E and G, respectively) and high thermal stability Tg and Td) can be obtained only if the fluorinated compounds of this invention are used.
The above conclusions are derived from calculations using an extended "Quasi-Lattice theory" (C. Lee, JMS Rev. Macromol. Chem. Phys., C29(4):431-560 (1989), incorporated herein fully by reference, and a "topological approach" employed by J. Bicerano, Prediction of Polymer Properties, Second Edition, Marcel Dekker, Inc., New York (1996), incorporated herein fully by reference, indicated that low dielectric constant materials with high thermal stability and high rigidity can be achieved with precursors containing sp2C—F and sp2C bonds.
Although the above calculations using cohesive energy may account for the mechanical and electrical properties of dielectric materials of the present invention, other theories may also explain the observations. Accordingly, the instant invention is not limited to any particular theory which may explain the desired properties of the herein disclosed dielectric precursors.
Therefore, the precursors of this invention contain both single and conjugated double bonds. Additionally, hyperconjugation of sp3C—F with sp2C bonds results in increased bond strength of the sp3C—F compared to other sp3 C—F bonds (such as in polytetrafluoroethylene) which are not hyperconjugated.
However, although precursors which contain double bonded carbon atoms without fluorine (sp2C═sp2C) have desirable Td, Tg, E, and G, the dielectric constant K is too high to be useful in the newer, smaller integrated circuits. Thus, the invention comprises incorporating fluorine atoms bonded to the double bonded carbon atoms in the precursor molecules (sp2C—F) into dielectric materials.
The precursors comprise compounds containing sp2C—F bonds and functional groups which can be cleaved or oxidized using a transport polymerization (TP) or chemical vapor deposition (CVD) process to yield reactive intermediates which spontaneously polymerize on the wafer substrate. Both linearly conjugated polymers and aromatic moieties can be used, but preferred moieties are aromatic. Also preferred are multiple-ring aromatic moieties, and the most preferred are single-ring aromatic moieties such as phenyl rings (e.g., —C6H4—, —C6H5).
A single fluorine atom incorporated into an aromatic moiety decreases the dielectric constant of that moiety, and further Increasing the number of fluorine atoms in the aromatic moiety further decreases K. Thus, the general formula for mono-fractional aromatic precursors of the invention is: —C6H5-nFn, wherein n is an integer selected from the group of 1, 2, 3, 4 or 5. Similarly, the general formula for di-functional aromatic precursors is: —C6H4-nFn—, wherein n is an integer selected from the group of 1, 2, 3 or 4. The most preferred embodiments are aromatic moieties which have maximal substitution of sp2C—H hydrogen atoms by sp2C—F fluorine atoms. Thus, for a precursor containing only one functional group, the mono-fluorinated phenyl group —C6H4F works, but multi-fluorinated phenyl groups are preferred, and —C6F5 is most preferred. For a precursor containing two functional groups, the mono-fluorinated phenyl group —C6H3F— works, but multi-fluorinated phenyl groups are preferred, and —C6F4— is most preferred.
A. Fluorocarbon-Modified SiO2: Fluorinated Silanes and Fluorinated Siloxanes
The first category of precursors consists of precursors for making fluorocarbons, fluorinated silanes and fluorinated siloxane. These precursors are useful for modifying SiO2 by incorporating Si—C bonds, Si—F bonds, and/or fluorinated aromatic bonds. Incorporation of these types of bonded moieties into SiO2 can lower the dielectric constant, but with only small decreases of the Td, Tg, E, and G of the polymers from which they are made.
Precursors of fluorinated silanes in this invention have the general structural formula: (C6H5-nFn)m—SiH4-m, wherein n is 1, 2, 3, 4 or 5 and n is an integer of 1, 2, 3 or 4. The preferred fluorinated silane of the present invention is C6F5—SiH3.
Precursors of fluorinated siloxanes of this invention have the general structural formula: (C6H5-nFn)m—Si(OCH3)4-m, wherein n is 1, 2, 3, 4 or 5, and m is 1, 2, or 3. The preferred fluorinated siloxane of the present invention is (C6F5)—Si(OCH3)3.
Precursors of fluorinated hydrocarbons have the general structural formula: CH3-nFn—C6H4-pFp—CH3-mFm, wherein n and m are 1, 2 or 3, and p is 1, 2, 3, or 4. Preferred fluorinated hydrocarbon precursors are CF3—C6F4—CF3 and CHF2—C6F4—CHF2.
There are many isomers with these above general formulas, and all are considered part of the present invention.
Precursors and Methods for Manufacturing
Low Dielectric SiO2 Derivatives
C & F-source
Si Source
TP and CVD Processes
Plasma Enhanced
Plasma Enhanced
Table 2 shows the precursors, other reactants and TP and CVD processes used to manufacture fluorine-substituted aromatic SiO2 derivatives of this invention. Although the fully fluorinated derivatives are described, mono-, di-, tri-, and tetra-fluorinated aromatic moieties, as appropriate, can also be used.
B. Precursors for Making Fluorinated Amorphous Carbon- and Polymer-Containing Materials With Low Dielectric Constant
These precursors consist primarily of sp2C═sp2C, sp2C—F and/or hyperconjugated sp3C—F bonds. Unlike the precursors used for making silanes and siloxanes, no Si source is needed.
Precursors for fluorinated polymers ,with one aromatic ring and one sp2C—sp3C—F type bond have the general formula: (C6H5-nFn)—CH3-mFm, where n is an integer of 1, 2, 3, 4, or 5, and m is an integer of 1, 2, or 3. A preferred precursor of a fluorinated polymer is C6F5—CF3.
Precursors for fluorinated polymers with one aromatic ring and two sp2C—sp3C—F type bonds have the general formula: (CH3-nFn)—(C6H4-pFp)—(CH3-mFm), wherein n and m are integers selected from the group consisting of 1, 2 and 3, and p is an integer selected from the group consisting of 1, 2, 3, and 4. The precursors of fluorinated polymers which are commercially available include CF3—C6F4—CF3 and CHF2—C6F4—CHF2.
Precursors of polymers containing one fluorinated aromatic residue and an additional conjugated sp2C carbon bond have the general structural formula: (C6H5-nFn)—CH1-mFm═CH2-pFp, where n is an integer of 1, 2, 3, 4, or 5, m is an integer of 0 or 1, and p is an integer of 0, 1, or 2. The preferred precursor of this group is C6F5—CF═CF2.
There are many isomers with these above general formulas, and all are considered part of the present invention.
Precursors for Making Low Dielectric Hydrocarbon Polymers
C & F-sources
Primary α-C Source
TP or CVD Process
High Density Plasma
High Density Plasma
Thermal or Photon Assisted
Photon Assisted
II. Deposition of Low Dielectric Materials
The invention comprises new methods and precursors for depositing low dielectric materials. These new methods and precursors have advantages over conventional methods.
During conventional manufacture of semiconductors using spin-on glass (SOG) methods, defects in the dielectric layers can form, especially in locations where there is a channel between metal lines. Such defects in the dielectric layers result in the formation of cracks or "voids" in the dielectric material. These voids and cracks result in trapping moisture, etching gas, or photoresist contaminants and ultimately lead to the degradation and loss of device reliability. Therefore, the present invention provides precursors which can be deposited using chemical vapor deposition (CVD) and transport polymerization (TP) to avoid the problem.
In CVD, a precursor is placed directly on the substrate which will have the thin film of low dielectric material applied. In his "hot chuck" method, the wafer and precursor are exposed to an energy source such as heat, plasma, or electromagnetic radiation to "dissociate" or "crack" the precursor molecule directly on the wafer to form the reactive intermediate. The reactive intermediate molecules then polymerize with each other to form the thin film.
In TP, the cracking step is performed an a chamber other than where the deposition step is performed. This "cold-chuck" method confers several advantages. First, the cracking efficiency can be optimized by selecting appropriate conditions of plasma density, photon energy, or temperature. Second, the density of the intermediate molecules can be regulated to minimize the formation of unwanted side products, such as re-formed precursors. Next, because the wafer is not exposed to the harsh conditions of precursor dissociation, fragile structures containing aluminum or other thermally sensitive materials are less likely to become damaged. Deposition of polymer layers of a few nanometers (nm) to>7000 nm can be achieved, along with eliminating or greatly reducing the number of voids. In principle, layers of polymer of molecular dimensions can be deposited. Thus, the invention provides the novel precursors for the deposition of void-free dielectric films. The type of functional group used determines the optimal type of TP or CVD process should be used. These will be discussed below.
A. General Processes for the Manufacture of Fluorinated Aromatic Derivatives of Silanes and Siloxanes Using Thermal Transport Polymerization and Chemical Vapor Deposition
For preparations of the low K dielectrics of this embodiment according to the Table 2, the concentration of the fluorinated aromatic silane is in the range of from about 5% to 100%, and is preferably 20%. The fluorinated aromatic siloxane is used in the range of from about 5% to about 100%, and is preferably 20%. In a plasma enhanced chemical vapor deposition (PECVD) and photon-assisted transport polymerization (TP) processes, no oxidants are required, but in a thermal TP or thermal CVD process an oxidant such as H2O2 or NO2 is added to oxidize the Si atoms of SiH4 or other silane. Other suitable oxidants are oxygen containing organic or in organic compounds, such as oxalic acid. When H2O2 is used, its concentration should be in the range of about 10% to about 50%, and is preferably about 30%.
Thermal TP is carried out in a chamber 100 shown in FIG. 1. The precursors are contained within a precursor tank 104, flow through a pipe 108 into a mass flow controller 112 from which they are controllably released through another pipe 116 into the chamber 120 within which is a container 124 with a cracking device that may comprise a catalyst 128. The precursors are heated by a conventional resistive heater 132 to generate the reactive intermediate radicals. Rates of precursor flow range from 0.2 SCCM to 100 SCCM, preferably between 2 and 5 SCCM, and most preferably at 3 SCCM. Temperatures of reactions without catalysts should range from about 700� C. to about 800� C., preferably are in the range of from about 700� C. to about 750� C., and most preferably at about 750� C. For reactions in the presence of catalysts, temperatures can be as low as about 350� C. The pressure in the chamber 120 needed for the cracking reaction should be in the range of about 1 milliTorr to about 500 Torr, and is preferably about 10 milliTorr. After cracking, the intermediates flow to a diffusion plate 136 where the bulk flow is diverted away from the wafer 140. The diffusion plate 136 can be positioned as desired within the chamber, to optimize the pattern of flow of intermediates to the wafer. The intermediates then diffuse to the wafer 140, which is held on a cold chuck 144 which is maintained at a temperature lower than the cracking device by a chiller 148. Temperatures are maintained by any conventional cooling method including liquid nitrogen or reverse Peltier methods. Temperatures of the chuck should be in the range of about −120� C. to about 300� C. are useful, preferred temperatures are in the range of about −40� C. to about 100� C., and the most preferred temperature is about −20� C. The chamber 120 is connected via a pipe 152, to a cold trap 156, and another pipe 160 connects the trap to a pump 156 to maintain low pressure in the chamber 120. The cold trap 156 protects the pump 160 from deposition of precursors and intermediates in the chamber 120.
1. Use of Catalysts in Thermal TP and Thermal CVD
Thermal TP and CVD processes requiring catalysts to dissociate precursor molecules into reactive intermediates can use any conventional catalyst. An ideal catalyst useful for this invention should provide high reactivity, high selectivity, long process life cycle, high recycle capability, and less severe pressure and temperature requirements. It should be inexpensive, safe for human handling, and should be environmentally friendly. The catalyst should crack or cleave the Si—H and crack or oxidize the C—H bonds. Further, the catalyst should not add any metal or metal compound, or reactive ion such as F− into the dielectric film during deposition. Serious reliability problems occur when a metal contaminant resides within the dielectric materials. Other serious problems occur when a highly reactive ion such as F− is introduced into the film. The ion can break interatomic bonds within the hydrocarbon moieties of the dielectric material, resulting in lowered mechanical strength.
Catalysts that are useful for this invention include dehydrogenation catalysts, reforming catalysts, and oxidative dehydration catalysts.
a. Dehydrogenation Catalysts
The temperatures and times needed to complete pyrolysis can be reduced by employing a catalyst in the chamber. An ideal catalyst useful for this invention should provide high reactivity, high selectivity, long process life cycle, high recycle capability, and less severe pressure and temperature requirements. It should be inexpensive, safe for human handling, and should be environmentally friendly. The ideal catalyst should crack or cleave the Si—H and C—H bonds without cracking or cleaving the C—F bonds. Further, the catalyst should not add any metal or metal compound into the dielectric film during deposition. Serious reliability problems occur when a metal contaminant resides within the dielectric materials.
To assist the cracking of the SiH and C—H bonds, any commonly used dehydrogenation catalyst is suitable. These catalysts are also called "protolytic cracking catalysts", or "oxidative dehydrogenation catalysts", in petroleum processing. Additionally, most "dehydrocyclization catalysts" and some of the "aromatization catalysts" for hydrocarbon processing are also useful for this invention, because aromatization normally involves dehydrogenation.
Potassium ferrite (KFeO2) on iron oxide is an example of a suitable catalyst which is commercially available. The ferrite commonly comprises a promoter that may contain a salt of oxide of a Group (IIA) metal, such as Mg, Ca, or Sr, and a Group VB or VIB metal, such as V, Nb, Cr, Mo. or W. [See J. I. Krochiwitz ed., Encyclopedia of Chemical Technology, 4th edition, Catalysis and Catalysts, Vol. 5: 320 (1991), incorporated herein fully by reference.] These catalysts can be useful at temperatures up to about 600� C. Variations of these catalysts are BASF's Lu-144F™ and Shell 105™ catalysts, and catalysts for the dehydrogenation of ethylbenzene. These include those produced by Monsanto-Combustion Engineering-Lumis, Union Carbide-Cosden-Badger, and Societe-Chimique des Charbonnages. [See J. J. McKetta, Ed., Encyclopedia of Chemical Processing and Designs: Dehydrogenation, Vol. 14:276, Marcel Dekker Inc. (1992), incorporated herein fully by reference.]
Other industrial catalysts include Cu and Zn oxides on alumina and Cu, Ag or Cu—Ag alloy in the form of gauge or as metal deposited on a low surface area support such as kaolin, clay and active carbon. Other supports or carriers can include asbestos, pumice, kiesselguhr, bauxite, CuO, Cr2O, MgCO3, ZrO2, and Zeolites. These catalysts are active by virtue of an oxide layer on the metals, and are used for hydrogen generation from methanol. Catalysts consist of copper chromite, bismuth molybdate, iron molybdate, or tin phosphate on similar supports are also useful. [See J. I. Krochiwitz ed., Encyclopedia of Chemical Technology, 4th edition, Catalysis and Catalysts, Vol. 5: 320 (1991), incorporated herein fully by reference; J. J. McKetta, Ed., Encyclopedia of Chemical Processing and Designs: Dehydrogenation, Vol. 14:276, Marcel Dekker Inc. (1992), incorporated herein fully by reference.]
b. Reforming Catalysts
In addition to dehydrogenation catalysts, reforming catalysts used in petroleum reforming processes can also be used. A first group of these include transition metal oxides, such as V2O5, MoO3, WO3 and Cr2O3 in bulk form or preferred on a non-acid support such as silica, neutral alumina or active carbon. [See Meriaudeau and Naccache, Cat. Rev.-Eng. Sci. 39(1&2):5-48 (1997), incorporated herein fully by reference. Typically useful catalysts include Shell 205™, which consists of 62.5% Fe2O3, 2.2% Cr2O3, and 35.3% K2CO3, and Dow Type B™ catalyst, which consists of calcium and nickel phosphates promoted with a small amount of chromium oxide.
Another group of reforming catalysts useful for dehydrogenation include noble metals on acid supports. The most commonly used catalysts are Pt (0.3 to 0.7%) and Pt/Re on a chlorided (acidified) alumina (e.g., γ- or η-Al2O3). The bimetallic Pt/Re-alumina is preferred for its longer life time. In addition, Pt, Ga or An modified H-ZSM-5™, or Pt on medium-pore zeolite support such as In-ZSM-5™ is also very effective.
Other, multimetallic reforming catalysts include Pt/Re catalysts of the above including lesser amounts of Ir, Ga, Ge, Sn or Pb supported by chlorided alumina. The catalysts typically have surface areas ranging from 170 m2/g to 300 m2/g and pore volumes ranging from 0.45 cm3/g to 0.65 cm3/g. [See J. I. Krochiwitz ed., Encyclopedia of Chemical Technology, 4th edition, Catalysis and Catalysts, Vol. 5: 320 (1991), incorporated herein fully by reference.] Additionally useful catalysts can also be found in the OJG International refining catalyst compilation-1987 (J. J. McKetta ed., Encyclopedia of Chemical Processing and Designs: Petroleum Processing, Catalyst Usage, Vol 35:87-89 Marcel Dekker (1992), incorporated herein fully by reference.] These catalysts comprise active agents such as Pt/ReCl, Ni, PtCl and other rare earth metals on alumina and zeolites.
Other useful catalysts in this invention include (1) noble metals or metal sulfide on active carbon, (2) Ga13, Cr12, GaAl12 & Al13 on PILCs, (3) M—Al2O3 with M=lanthanides, (4) Al2O3 kneaded with M, where M is Bi & Sb compounded with periodic table Group VIB & VIIB metals, (5) M-modified H-ZSM-5 and H-ZSM-11 where M is Zn, Ga, Pt—Ga, Pt—Na, Mo, Cr, K, Ca, Mg, Al, and Group VIII metals, (6) M-modified MFI (H-GalloSilicates) where M is Si/Ga, Na/Ga, Al, (7) rare earth metal exchanged Y-zeolites or ultra stable Y-zeolites, (8) Ti oxide paired with Zr oxide, (9) M plated onto aluminum, where M is Ni, and Ni, Cr, and Al alloys.
Pure dehydrogenations are endothermic by 15 to 35 kcal/g-mol. and hence have high heat requirements. The above catalysts are normally used at temperatures ranging from 300� C. to 600� C. depending on the residence time of the chemicals in the reactor. The effective temperature for some of these catalysts can be lowered by adding free radical initiators such as I, Br, H2O, sulfur compounds or oxygen and their mixtures. However, special care should be taken to avoid reaction of desirable radicals with free radicals generated from these initiators. This can be achieved by providing large mean free paths for these reactants in the reactor, reducing residence time and the adjustment of wafer temperatures to avoid condensation of low mass free radicals.
2. Loss Of Catalyst Function
With time, catalysts may lose reactivity due to changing their oxidative state or coke formation. The life time of the catalysts can be increased at high operating temperatures or high partial pressure of hydrogen. If catalysts lose activity by coke accumulation, they can be regenerated by careful oxidation followed by reduction with hydrogen before being returned to service. [See: J. J. McKetta ed., Encyclopedia of Chemical Processing and Designs: Catalysis and Catalysts Vol. 6:420; Petroleum Processing, Catalyst Usage, Vol 35:89 Marcel Dekker, Inc. (1992), incorporated herein fully by reference.
After leaving the cracking device, the intermediates pass through a diffusion plate to disperse the intermediates evenly over the wafer surface. The intermediates deposit upon the wafer, which is held on a chuck, which, in turn, is connected to a chiller to maintain a temperature of the chuck and wafer below the temperature of the chamber and the intermediates. The temperature of the cold chuck is maintained in the range of about −30� C. to about +20� C., preferably at −20� C. Low pressure in the system is maintained by a vacuum pump with sufficient capacity to maintain the desired pressure within the CVD system. Condensation of precursors and intermediates on the pump is minimized by a trap placed between the deposition chamber and the vacuum pump.
The sp2C—F-modified SiO2 thin films can be prepared from thermal oxidation of C6F5—SiH3. An admixture of 40 mole % of SiH4 and 60 mole % of C6F5—SiH3 in an aqueous solution with 30% by weight of H2O2 are dispensed separately through two flash evaporators onto a cold wafer inside a CVD system. The molar ratio of H2O2/(SiH4+C6F5—SiH3) is about 3.5. The mixtures of H2O2, SiH4, and C6F5—SiH3 is chilled as a thin film on the wafer. The wafer is then heated from −20� C. to 500� C. in vacuum at a heating rate of 10� C./min. The resulting thin film has a dielectric constant of 2.7 and an initial decomposition temperature of 480� C. when tested under nitrogen atmosphere.
B. General Methods for the Manufacture of Low Dielectric Thin Films Using Plasma TP or CVD
Plasma enhanced TP is carried out generally using methods in the art. Takai et al., J. Appl. Phys. 17:399-406 (1984), incorporated herein fully by reference. With low density plasma, the electron density in the plasma is in the range of about 1012 to about 1013 electrons/cm3. Low density plasma TP and CVD can be carried out at about 100 milliTorr to about 100 Torr. High density plasma (HDP) is characterized by electron densities in the range of about 1013 to about 1014 electrons/cm3. High density plasma TP and CVD can be carried out at pressures of about 0.1 milliTorr to about 100 milliTorr.
For preparation of the materials with low dielectric constants embodying this invention, reactants such as SiH4, or more generally siloxane such as Si(OCH3)4 are used. In a thermal CVD process, the presence of oxygen at high temperatures will induce oxidation, resulting in the formation of silicon dioxide (SiO2) films having varying K based on varying the relative compositions of SiO2 and sp2C—F bonded molecules.
1. Plasma Enhanced Transport Polymerization of Fluorinated Silanes and Fluorinated Siloxanes
To make thin films, sp2C—F-containing starting materials such as (C6H5-nFn)m—Si(0CH3)4-m wherein n is an integer of 1, 2, 3, 4, or 5, and m is an integer of 1, 2, or 3, (C6H5-nFn)m—SiH4-m wherein n is an integer of 1, 2, 3, 4, or 5, and m is an integer of 1, 2, 3, or 4, C6F5—CF3, or admixtures of these starting materials are delivered into a plasma enhanced transport system 200 depicted in FIG. 2. Precursors are stored in a precursor holder 204. A carrier gas, typically helium, is passed through a bubbling device to volatilize the precursor. The vaporized precursors flow through a pipe 208 and to a mass flow controller 212. The mass flow controller (MFC) provides a precursor feed rate ranging from about 0.2 to about 500 standard cubic centimeter per minute (SCCM). The precursors flow from the MFC 212 through a pipe 216 and into a quartz tube 220 under low pressures in the range of from about 0.1 milliTorr to 10 Torr, and preferably in the range from about 1 milliTorr to about 3 milliTorr. A carbon source such as CH4 or C2H2 is provided via a second feeder (not shown) and a second MFC (not shown) with a feed rate ranging from 0 to 500 SCCM. The preferred flow rates of precursor into the plasma tube should be in the range of from about 0.2 SCCM to about 10 SCCM, and is most preferably in the range of about 0.5 SCCM to about 1 SCCM.
Pyrolization takes place within the quartz tube by action of a radiofrequency (RF) plasma generator 226. Effective plasma 230 can be maintained by radio frequencies in a range of between about 1 kHz and 2.5 GHz. A preferred range is between about 400 KHz and about 13.56 MHz. Ideally, the RF frequency is about 13.56 MHz. The RF power should be in the range of about 30 Watts to 300 Watts, preferably about 100 Watts to 250 Watts, and more preferably about 200 Watts.
The plasma 230 then proceeds into the deposition chamber 234 which is heated by a heater 238 to prevent deposition of precursor intermediates on the chamber walls. The pressure within the chamber 230 is maintained at a pressure between about 0.1 milliTorr and about 10 Torr. The flow of plasma is adjusted by a flow pattern adjuster 242, which can be moved within the chamber. Moving the flow pattern adjuster 242 in the vertical direction adjusts the flow rate and distribution pattern of the plasma as it enters the chamber. Moving the flow pattern adjuster in the horizontal direction adjusts the distribution of plasma to different parts of the wafer 250. A gas dispersion plate 246 evens the delivery of the intermediates to the wafer 250. The wafer 250 is cooled by the chuck 254, which is cooled by liquid nitrogen, reverse Peltier effect, or other conventional cooling device 258, and is maintained at a temperature in the range of about −30� C. to about +20� C., and is preferably about −10� C. The deposition chamber 224 is connected via a pipe 262 to a cryogenic trap 266, which is connected via a pipe 270 to a pump 276, which maintains the pressure within the chamber at the desired level.
2. High Density Plasma Chemical Vapor Deposition
A high density plasma deposition process can also be used to dissociate precursors. In contrast to the low density plasma process described above, in high density plasmas, the electron density is in the range of from about 1013 to 1014 electrons/cm3. This process must be carried at lower pressures than conventional plasma processes. In this embodiment, a inductively coupled high density plasma apparatus 300 is shown schematically in FIG. 3. A precursor delivery system 304 volatilizes or vaporizes the precursor, which flows through a pipe 308 and an anode gas injector 312 into the deposition chamber 316. The anode gas injector 312 is attached to RF generators 320 which are matched by matching controllers 324. The output of the RF generators 320 passes through inductive coils 328 to produce an electrical field. The wafer 332 is held by a cathode electrostatic chuck 336, which is connected to the RF generator 320. IR sources 340 provide additional heating of precursors to decrease the needed plasma power and to inhibit condensation of materials on the walls of the chambers. The plasma source power needed for a wafer of 8 inch diameter is in the range of about 100 Watts to 4000 Watts, and preferably about 2000 Watts. For wafer of other sizes, the power should be adjusted accordingly. Power should range from about 1 Watt/cm2 wafer surface area to about 15 Watts/cm2, preferably from about 2 Watts/cm2 to about 10 Watts/cm2, and most preferably about 5 Watts/cm2. The chamber pressure is maintained in the range of 0.01 milliTorr to 10 milliTorr, and preferably below 5 milliTorr. The wafer temperature is in the range from about 300� C. to 450� C., and is preferably about 350� C.
Generally, thin films made using plasma methods contain lower carbon content than films made using thermal methods. Films with decreased carbon content are made using greater plasma power. One theory to account for this is that increasing the plasma power increases the dissociation of the precursors by more completely cracking the precursors. Decreasing the carbon content of films decreases the trapping of electrons in the film, and leads to more reliable, long lasting devices.
The deposition rate can be regulated by adjusting the flow rate of precursors into the plasma generator and thereby adjusting the flow rate of reactive intermediates over the wafer. However, as the precursor flow rate increases, the residence time within the plasma generator decreases, and this can result in less complete cracking. To overcome this problem, it is desirable to increase the plasma power as the precursor flow rate increases. This maintains the efficiency of the cracking reaction.
If desired, further increases in the efficiency of the plasma reactions can be achieved by heating the chamber. This can be done using a conventional resistive heater or using an infrared (IR) heater. Preferably, IR irradiation is used, and the wavelength of the IR radiation is chosen to maximal absorption by the precursor.
The above reaction is designed to accommodate wafers with diameters of about 200 mm. Thin films of this invention are deposited at a rate of about 1000 Å/min. Films deposited using this system have dielectric constants of 2.3 to 3.5, and have Td in the range of about 350� C. to 500� C., depending on the fluorine content. Increasing the fluorine content decreases the dielectric constant. The thin films have no initial weight loss; Td and Tg are temperatures ranging from 450� C. to 500� C. under nitrogen atmosphere.
A thin film of C6F5—Si(OCH3)3 is made using a parallel type of plasma reactor as depicted in FIG. 3. The compound is delivered into the chamber employing a bubbling device using Ar as a carrier gas. The compound is introduced at a feed rate of 50 SCCM. The operating chamber pressure is 20 milliTorr. Effective plasma is maintained by an RF frequency of 13.56 MHz at a power of 1.3 Watts/cm2 applied to the upper electrode with a wafer placed on the lower electrode which is grounded. The wafer temperature is maintained at 400� C. The thin film made by this process has a dielectric constant of 2.65, and has no initial weight loss at 500� C. under nitrogen atmosphere.
C. General Methods for the Manufacture of Low Dielectric Thin Films Using Photon Assisted Transport Polymerization
In addition to thermally and plasma- generated reactive intermediates, photon assisted precursor cracking is also part of this invention. Because specific chemical bonds have specific energies, and because these energies can be supplied as photons, electromagnetic radiation is a preferred method of practicing this invention.
A transport polymerization system 400 using electromagnetic radiation is shown in FIG. 4. Precursors are stored in a precursor tank 404 and then flow through a pipe 408 to a mass flow controller 412, where the precursor flow rate is regulated. Volatile precursor then passes through pipe 416 into a transparent tube 420. For UV photolytic cracking of the precursor, tube 420 is made of quartz, preferably a single quartz crystal. For infrared (IR) cracking of the precursor, tube 420 may be made of glass. For vacuum ultraviolet photolytic cracking of the precursor, tube 420 is made of MgF2, LiF, or CaF2. An ultraviolet (UV) source 424 is used to photolytically dissociate the precursor. Alternatively, a vacuum ultraviolet (VUV) 426 source can be used. An infrared (IR) source 428 can be used, which heats the precursors to provide a combination of thermolytic and photolytic cracking. After cracking, the intermediates pass into the deposition chamber 432, which is heated by a resistive heater 436 to prevent deposition of intermediates on the walls of chamber 432. The flow of intermediates is adjusted using flow pattern adjuster 440. Moving the flow pattern adjuster 440 in the vertical direction adjusts the flow rate of and the distribution pattern of intermediates in the deposition chamber 432. Moving the flow pattern adjuster 440 in the horizontal direction adjusts the distribution pattern of intermediates in the deposition chamber 432. A gas dispersion plate 444 evens the delivery of the intermediates to the wafer 448. The wafer 448 is held by a cold chuck 452, which is maintained at low temperatures by a conventional cooling device, using liquid nitrogen, reverse Peltier effect, or any other cooling apparatus known in the art. The chamber 432 is connected via a pipe 460 to a trap 464, which is connected via another pipe 468 to a pump 472. The pump maintains the pressure within the deposition chamber 432 at the desired level, and the trap 464 minimizes the deposition of intermediates on the pump 472.
Using the photolytic method, the dissociation reaction can be very selective and efficient if appropriate photon sources are used. The photon sources can be provided by ultraviolet (UV) light generated by mercury vapor discharge or metal halide lamps. Exemplary sources of UV radiation for transport polymerization can include (1) a mercury lamp that provides from 50 to 220 mWatts/cm2 of UV ranging from 200 to 450 nm or (2) a metal halide lamp that provides from 40 to 160 mWatts/cm2 of UV ranging from 260 nm to 450 nm. These UV sources provide photon energies ranging from 2 to 5 eV, which are sufficient for generating many radical intermediates.
An alternative to conventional UV light is vacuum ultraviolet (VUV). Incoherent excimer radiation can provide a large number of UV and VUV wavelengths for photolytic processing of various chemicals. The preferred source is incoherent excimer radiation derived from dielectric barrier discharge. UV and VUV photons that are in the ranges of 3 to 5 eV are especially useful. These energy levels are comparable with the bonding energies of most chemical bonds, thus are very effective for initiating photochemical reactions (see Table 4).
Bond Energies of Selected Bonds
Chemical Bonds
Bonding Energies (eV)
Table 4 shows the bonding energies in electron volts (eV) corresponding to certain bonds of this invention. This data is from Streitwiesser et al., Introduction to Organic Chemistry, Appendix II, University of California Press, Berkeley, Calif. (1992), incorporated herein fully by reference.
However, the energies of mercury vapor or metal halide UV radiation are too small to be useful for rapid transport polymerization. The desired residence time within the cracking chamber, which is the time available for photolysis should be in the range of a few milliseconds to several hundred milliseconds. Therefore, VUV is the most desirable form of energy for photon assisted transport polymerization.
VUV or incoherent excimer UV sources can be provided by dielectric barrier or silent discharge. For example, VUV can be generated using KrBr, Ar2, ArCl, ArBr, Xe2 and F2 gases. Xe emits at 172 nm, Kr at 222 nm, and XeCl emits at 308 nm. As can be seen from Table 2, nearly all of the chemical bonds of interest in polymer manufacture can be broken using photolytic methods. Because excimer radiation is selective for the energy of the specific bonds, excimer radiation from another source or plasma may be used simultaneously if it is desired to break other bonds at the same time. Such a combination of excimer and plasma sources are useful to break bonds of precursors of cross-linked poly(para-xylylenes). Because the leaving groups of these precursors may be different, it is desirable to break those bonds selectively to generate tri- and tetra-functional reactive intermediates.
When IR incoherent excimer irradiation is used, the conventional stainless steel or ceramic pipe or reactor used in the pyrolyzer will have to be replaced with a quartz tube or reactor. When using UV, the transparent tube shown in FIG. 4 can be made of any UV transparent material such as quartz, preferably a single quartz crystal. When using VUV, the transparent tube must be made of a material transparent to VUV wavelengths. Crystals of MgF2, LiF, or CaF2 are preferred.
Operating Conditions for Photon Assisted Dissociation of Precursors
Preferred Range
Photon Wavelength
100-400 nm
140-300 nm
Photon Energy
2.5-12 eV
4-9 eV
Photon Flux
5 mW/cm2-10 W/cm2
40-100 mW/cm2
Reaction Chamber Pressure
0.1 milliTorr-10 Torr
1-100 milliTorr
Reaction Chamber Tem-
Deposition Chamber Tem-
−30 to +20� C.
Deposition Chamber Pressure
0.1 milliTorr-10 Torr
1-100 milliTorr
In one embodiment of this invention, photon assisted dissociation occurs immediately above the wafer surface onto which the film is to be deposited. Because no transport of intermediates is needed, the efficiency of deposition is increased. Further, the photon energy or mixtures of photon energy (from mixed excimer gases) could be made to both dissociate the precursor as well as promote nucleation and adhesion of the polymer based films.
D. General Methods for the Manufacture of Low Dielectric Thin Films Using Photon-Plasma Assisted Precursor Dissociation and Deposition
Additionally, a combined photon-plasma process is used for dissociation of precursors and deposition of thin films of low dielectric materials. Photon energy is used to generate a plasma in certain gases. In this embodiment of the invention, the attributes of plasma, generally high rates of dissociation, along with the cool photon energy source, provides a unique method for both precursor dissociation and even film deposition. Additionally, infrared (IR) radiation can be used to heat reactor elements and precursors. Pre-heating precursors increases the efficiency of photon and plasma dissociation of the precursors. Moreover, the photon plasma can be directed toward the surface on which films are being deposited.
FIG. 5 depicts a schematic diagram of a TP and CVD reactor 500 embodying the elements for photon-plasma and IR dissociation and deposition. Precursors 504 are stored in a precursor container 508 which is connected via a pipe 512 to a mass flow controller 516. For TP, precursors are transported into a dissociation reactor 524 which houses the dissociation chamber 528. The wall of reactor 524 is made of crystalline materials such as LiF, MgF2, or CaF2, which permits light of vacuum ultraviolet wavelengths to pass. Vacuum ultraviolet and ultraviolet light is generated by a silent discharge plasma generators 532, which are place inside infrared heaters 536. The infrared heaters 536 are placed inside DC magnets 540 and AC magnets 544. The magnets regulate the flow of plasma during dissociation, and the reactive intermediates so generated are transported to a deposition reactor 550.
The deposition reactor 550 contains a deposition chamber 560 containing a gas and reactant dispersion manifold 554, a gas and reactant dispersion plate 558. The walls of the deposition chamber are made of crystalline materials such as LiF, MgF2, or CaF2, which permits light of vacuum ultraviolet wavelengths to pass. The gas dispersion manifold 554 and the gas dispersion plate 558, are used to adjust the distribution and homogeneity of the intermediates. The intermediates are directed toward the wafer 562, which is held on a cold chuck 564. The gas dispersion manifold 554 and dispersion plate 558 are connected in parallel to a DC voltage bias anode 568, a DC voltage bias cathode 569, an AC voltage bias anode 570, and an AC voltage bias cathode 571. Silent discharge plasma generators 572 are placed outside the deposition chamber 560. Infrared heaters 574 are placed outside the silent plasma discharge generators 560 and DC magnets 578 and AC magnets 580 are placed outside the infrared heaters 574. Gases exit the deposition chamber 560 through a pipe 584, pass through a cold or reactive trap 588, pass through another pipe 592 to a vacuum pump 596. The pressure in the systems is maintained at a desired pressure using pump 596. The trap 588 protects the pump from deposition of intermediates.
For CVD, the deposition chamber can be used without the dissociation reactor.
Precursors are placed directly on wafer 562, and the chuck 564 is not cooled. IR, UV, or VUV radiation is directed toward the wafer 562. The radiation dissociates the precursor, and deposition of intermediates and polymerization takes place on the wafer.
Table 6 shows process conditions for combined photon-plasma assisted precursor dissociation using chamber 528, and Table 7 shows process conditions for combined photon-plasma precursor deposition in chamber 560.
Process Conditions for Photon-Plasma Precursor Dissociation
Preferred Range
Photon Wavelength
100 nm-400 nm
140 nm-300 nm
Photon Energy
2.5 eV-12 eV
4 eV-9 eV
Photon Flux
10 milliW/cm2-5 W/cm2
40-100 milliW/cm2
Plasma Density
1012-1014 electrons/cm3
1013 electrons/cm3
0.1 milliTorr-10 Torr
1 milliTorr-10 milliTorr
Process Conditions for Photon-Plasma Precursor Deposition
Preferred Range
Photon Wavelength
100 nm-400 nm
250 nm
Photon Energy
2.5 eV-12 eV
4.5 eV
Photon Flux
10 milliW/cm2-5 W/cm2
10-100 milliW/cm2
Plasma Density
1012-1014 electrons/cm3
1013 electrons/cm3
0.1 milliTorr-10 Torr
1 milliTorr-10 milliTorr
In Tables 6 and 7, the plasma density is reported as electron density, but it is to be noted that ion density must be the same to maintain charge neutrality of the plasma. Any non-uniformity of charge distribution can result in plasma damage to the thin film of low dielectric material, as well as imparting charge to the integrated circuit components.
Control of the plasma is by a magnetic field within the precursor chamber and in the deposition chamber. In the precursor reactor, the plasma is confined to any desired area, such as the center of the reactor. Additionally, by alternating the polarity of the magnetic field stirs the plasma, ensuring even energy distribution within the plasma, thereby increasing the efficiency of dissociation of precursor molecules into reactive intermediates. In the deposition chamber, the magnetic field is used to control the pattern of distribution of intermediates over the wafer. This would serve two purposes: (1) to direct the deposition of precursor to the desired portion of the surface, thus conserving the precursor, and (2) minimize film deposition on other parts of the reactor chamber, thus minimizing the required cleaning, minimizing particle generation, and simplifying the reactor chamber design.
Another feature comprises the placement of an electrical bias voltage within the deposition chamber. This provides a further means of controlling the flow of plasma-ionized species to the site of deposition on the wafer. A bias voltage, in the form of direct current (DC) or alternating current (AC) can be applied and modulated. Pulsed voltages can be used to alter the flow pattern of ions to either accelerate, decelerate, or to regulate the density of the plasma ions in the stream reaching the wafer. Optimization of ion velocity and flow, thus can be obtained using various combinations of magnetic field and bias voltage.
Optimization of Electrical and Magnetic Field Variables
Preferred Range
DC Bias Voltage
AC Bias Voltage
Pulsed Bias Voltage
Pulse Width
10-1000 msec
1 msec
Pulse Frequency
10 Hz-1000 Hz
60 Hz
DC Magnetic Field Strength
100-2000 Gauss
700 Gauss
AC Magnetic Field Strength
100-1000 Gauss
500 Gauss
AC frequency
10 Hz-500 Hz
50 Hz-60 Hz
Table 8 shows the ranges of the various magnetic field and bias voltage variables which are regulated in this invention.
Other reactors and reactor configurations may be used, as exemplified by the above cited co-pending applications incorporated herein fully by reference.
The low dielectric constant materials are polymerized into thin films of thicknesses of about 500 Å to about 5 μm on wafers for use in the manufacture of integrated circuits. FIG. 6 depicts a diagram of a multilevel integrated circuit chip 600 embodying the features of this invention. The substrate 604 has a source region 608, a drain region 612, and a polysilicon gate 616. A first interlevel dielectric (ILD) layer 620 overlays the substrate 600 and polysilicate gate 616. The wafer is subsequently planarized using chemical mechanical polishing another method known in the art. A floating polysilicon gate 624 is overlain by a second ILD layer 628. the wafer is again planarized, a first metal line 632 and a first intermetal dielectric (IMD) layer 636 are deposited. The wafer is again polished. On top of the IMD layer 636, a third metal line 640 and a second ILD layer 644 is deposited. The wafer is again planarized.
It should be appreciated by those of ordinary skill in the art that other embodiments may incorporate the concepts, methods, precursors, polymers, films, and devices of the above description and examples. The description and examples contained herein are not intended to limit the scope of the invention, but are included for illustration purposes only. It is to be understood that other embodiments of the invention can be developed and fall within the spirit and scope of the invention and claims.
Other features, aspects and objects of the invention can be obtained from a review of the figures and the claims.
The invention includes novel precursors containing a fluorinated silane, fluorinated siloxane and fluorocarbons, each containing a fluorinated aromatic moiety. The precursors are suitable for making polymers with low dielectric constants and high thermal stability.
Additionally, the invention includes methods for making polymers for integrated circuit manufacture using novel fluorinated siloxanes, fluorocarbons, and fluorinated aromatic moieties.
Furthermore, the invention includes integrated circuits made using fluorinated siloxanes, fluorocarbons, or fluorinated aromatic moieties, with low dielectric constants.
According to the present invention, the polymers made from the disclosed precursors have low dielectric constant and high thermal stability. Therefore, integrated circuits made from these precursors have improved electrical and mechanical properties.
|Cited Patent
|Filing date
|Publication date
|Jul 9, 1964
|Aug 23, 1966
|Union Carbide Corp
|Process for the preparation of cyclo
|Sep 23, 1963
|Sep 20, 1966
|Union Carbide Corp
|Cyclic alpha-perfluoro-di-p-xylylenes
|Feb 18, 1966
|Sep 19, 1967
|Union Carbide Corp
|Para-xylylene polymers
|Dec 13, 1965
|Apr 22, 1969
|Us Air Force
|Fluoroaromatic compounds
|Sep 4, 1979
|Sep 22, 1981
|Union Carbide Corporation
|Oct 28, 1983
|Jul 30, 1985
|Merck Patent Gesellschaft Mit Beschrankter Haftung
|Process for the preparation of [2,2]-paracyclophane
|Jun 15, 1984
|Oct 21, 1986
|Kabushiki Kaisha Toshiba
|Semiconductor device having a multilayer wiring structure using a polyimide resin
|Jan 22, 1986
|Apr 14, 1987
|Canon Kabushiki Kaisha
|Formation of deposited film
|Mar 31, 1987
|Apr 12, 1988
|Energy Conversion Devices, Inc.
|Plasma deposited coatings, and low temperature plasma method of making same
|Dec 4, 1986
|Mar 27, 1990
|Dow Corning Corporation
|Platinum or rhodium catalyzed multilayer ceramic coatings from hydrogen silsesquioxane resin and metal oxides
|Sep 28, 1990
|Aug 18, 1992
|Union Carbide Chemicals & Plastics Technology Corporation
|Method for inducing fluorescence in parylene films by an active plasma
|Dec 20, 1991
|May 11, 1993
|Union Carbide Chemicals & Plastics Technology Corporation
|Processes for the preparation of octafluoro-[2,2]paracyclophane
|Oct 9, 1992
|Dec 7, 1993
|Rensselaer Polytechnic Institute
|Vapor deposition of parylene-F using 1,4-bis (trifluoromethyl) benzene
|Jul 22, 1992
|Jun 28, 1994
|International Business Machines Corporation
|Low dielectric constant fluorinated polymers and methods of fabrication thereof
|Feb 22, 1993
|Aug 2, 1994
|Dow Corning Corporation
|Articles by plasma-activated chemical vapor deposition of fluorinated cyclic siloxanes
|Sep 30, 1993
|Jun 13, 1995
|Specialty Coating Systems, Inc.
|Continuous vapor deposition apparatus
|Oct 27, 1995
|Jul 9, 1996
|Specialty Coating Systems, Inc.
|Parylene deposition apparatus including a tapered deposition chamber and dual vacuum outlet pumping arrangement
|Oct 27, 1995
|Jul 16, 1996
|Specialty Coating Systems, Inc.
|Parylene deposition apparatus including a quartz crystal thickness/rate controller
|Oct 27, 1995
|Jul 16, 1996
|Specialty Coating Systems, Inc.
|Parylene deposition apparatus including an atmospheric shroud and inert gas source
|Oct 27, 1995
|Jul 16, 1996
|Specialty Coating Systems, Inc.
|Parylene deposition apparatus including a post-pyrolysis filtering chamber and a deposition chamber inlet filter
|Oct 27, 1995
|Jul 16, 1996
|Specialty Coating Systems, Inc.
|Parylene deposition apparatus including a heated and cooled support platen and an electrostatic clamping device
|Oct 18, 1995
|Jul 16, 1996
|Specialty Coating Systems, Inc.
|Processes for the preparation of octafluoro-[2,2]paracyclophane
|Oct 27, 1995
|Jul 23, 1996
|Specialty Coating Systems, Inc.
|Method and apparatus for the deposition of parylene AF4 onto semiconductor wafers
|Oct 27, 1995
|Sep 17, 1996
|Specialty Coating Systems, Inc.
|Parylene deposition apparatus including dry vacuum pump system and downstream cold trap
|Feb 14, 1994
|Jun 10, 1997
|Nitto Electric Industrial Co., Ltd.
|Thin adhesive sheet for working semiconductor wafers
|Jun 7, 1995
|Jul 22, 1997
|Texas Instruments Incorporated
|Semiconductor device fabrication method
|May 31, 1995
|Jan 13, 1998
|The United States Of America As Represented By The Secretary Of The Navy
|Low dielectric constant allylics
|Apr 11, 1997
|Jun 2, 1998
|Industrial Technology Research Institute
|Planarization method for intermetal dielectrics between multilevel interconnections on integrated circuits
|Feb 21, 1997
|Jul 21, 1998
|Copytele, Inc.
|Polymeric-coated dielectric particles and formulation and method for preparing same
|Oct 24, 1997
|Apr 18, 2000
|Quester Technology, Inc.
|Low dielectric constant materials and method
|Apr 29, 1998
|Feb 6, 2001
|Novellus Systems, Inc.
|Interlevel dielectric stack containing plasma deposited fluorinated amorphous carbon films for semiconductor devices
|Feb 7, 2001
|Dec 27, 2001
|Todd Michael A.
|Low dielectric constant materials and processes
|Oct 17, 1996
|Apr 23, 1997
|Low dielectric constant material for use as an insulation element in an electronic device
|Jan 18, 1999
|Jul 21, 1999
|Nippon Shokubai Kagaku Kogyo Kabushiki Kaisha
|Process for production of 1,4-bis(difluoroalkyl) benzene derivative
|Title not available
|May 3, 1996
|Nov 7, 1996
|Specialty Coating Systems, Inc.
|Flat panel display with parylene barrier and protective films
|Oct 18, 1996
|Apr 24, 1997
|Specialty Coating Systems, Inc.
|Processes for the preparation of octafluoro-[2,2]paracyclophane
|Oct 25, 1996
|May 1, 1997
|Specialty Coating Systems, Inc.
|Method and apparatus for the deposition of parylene af4 onto semiconductor wafers
|Oct 25, 1996
|May 1, 1997
|Specialty Coating Systems, Inc.
|Parylene polymer layers
|Oct 24, 1997
|May 7, 1998
|Specialty Coating Systems, Inc.
|Process for making a parylene coating
|Dec 5, 1997
|Jun 11, 1998
|Speciality Coating Systems, Inc.
|Tfpx synthesis
|Feb 25, 1998
|Sep 24, 1998
|Specialty Coating Systems, Inc.
|Af4 synthesis
|"Depostition of High Purity Parylene-F using Low Pressure Temperature Chemical Vapor Deposition", Wu et al., Journal of Electronic Materials, 26(8), 1997.*
|"Vapor Deposition Polymerization of 4-Fluorostyrene and Pentafluorostyrene", Bartlett et al., Journal of Vacuum Science and Technology B, 17(1), 1999.*
|Air Force Materials Laboratory, Structure-Stability Realationships of Polymers, based on Thermogravimetric Analysis Data, Part I: Polyaliphatics, Polyalicyclics, Spiro Polymers and Phenylene-R-Polymers, Technical Report ADML-TR-74-177, Part 1., 1974.
|Endo, Kazuhiko, Fluorinated Amorphous Carbon as a low-dielectric-constant interlayer dielectric, MRS Bulletin, Oct. 1997, p. 55-58.
|Hacker, Organic and Inorganic Spin-on Polymers for Low-Dielectric-Constant Applications, MRS Bulletin, 38-77, Oct. 1997.
|J.I. Krochiwitz, Encyclopedia of Chem. Tech., vol. 5, 320-373, 1991.
|J.J. McKetta, Encyclopedia of Chem. Proc. & Design, vol. 14, 276-291, 1992.
|Jozef Bicerano, Prediction of Polymer Properties, Second Edition, Marcel Dekker, Inc., pp. 1-15, 50-61, 108-111, and 280-295.
|Kudo, Hiroshi, Characteristics of Plasma-CF Films for Very Low-K Dielectrics, DUMIC Conference paper, Feb. 10-11, 1997, ISMIC-222D/97/0085.
|Labelle, et al., Characterization of Pulsed-Plasma Enhanced Chemical Vapor Deposited Fluorocarbon Thin Films, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC-222D/97/0098, 98-105.
|Labelle, et al., Characterization of Pulsed-Plasma Enhanced Chemical Vapor Deposited Fluorocarbon Thin Films, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC—222D/97/0098, 98-105.
|Lang, C.I., Vapor Deposition of Very Low K. Polymer Films, Poly(Naphthalene), Poly(fluorinated Naphthalene), Mat. Res. Soc. Symp. Proc. vol. 381, 1995.
|Lee, Chung J., Correlations of Elastic Modulus, Cohesive Energy Density and Heat Capacity Jump of Glassy Polymers, Polymer Engineering and Science, Jul. 1987, vol. 27, No. 13.
|Lee, Chung J., Direct Polymer Coating Via Polymerization of Gaseous Intermediates, Ind. Eng. Chem. Prod. Res. Dev., vol. 17, No. 1, 1978.
|Lee, Chung J., Polyimides, Polyquinolines and Polyquinoxalines: Tg-Structure Relationships, JMS-Reb. Macromol. Chem. Phys. C29)4, 431-560 (1989).
|Lee, et al., Low-Dielectric Constant materials for ULSI Interlaying-Dielectric Applications, MRS Bulletin, 19-27, Oct. 1997.
|Lee, Transport Polymerization of Gaseous Intermediates and Polymer Crystals Growth, J. Macromol. Sci.-Rev. Macromol. Chem., C16(1), 79-127 (1977-1978).
|Lee, Transport Polymerization of Gaseous Intermediates and Polymer Crystals Growth, J. Macromol. Sci.—Rev. Macromol. Chem., C16(1), 79-127 (1977-1978).
|Lu, et al., Vapor Deposition of Low-Dielectric-Constant Polymeric Thin Films, MRS Bulletin, 28-31, Oct. 1997.
|McClatchie, et al., Low Dielectric Constant Flowfill Technology for IMD Applications, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC-222D/97/0034, 34-40.
|McClatchie, et al., Low Dielectric Constant Flowfill Technology for IMD Applications, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC—222D/97/0034, 34-40.
|Meriaudeau, et al., Dehydrocyclization of Alkanes Over Zeolite-Supported Metal Catalysts: Monofunctional or Bifunctional Route, Catal. Rev. Sci. Eng., 39 (1&2), 5-48, 1997.
|Robles, et al., Characterization of High Density Plasma Chemical Vapor Deposited alpha-Carbon and alpha-Fluorinated Carbon Films for Ultra Low Dielectric Applications, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC-222D/97/0026, 26-33
|Robles, et al., Characterization of High Density Plasma Chemical Vapor Deposited α-Carbon and α-Fluorinated Carbon Films for Ultra Low Dielectric Applications, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC-222D/97/0026, 26-33
|Selebrede, Steven C., Characterization of Parylene-N Thin Films for Low Dielectric Constant VLSI Applications, DUMIC Conference papers, Feb. 10-11, 1997, ISMIC-222D/97/0121.
|Sharangpani, R., Advantages of Chemical Vapor Deposition Over Conventional Techniques for the Processing of Amorphous Teflon Fluoropolymer, DUMIC Conference paper, Feb. 10-11, 1997, ISMIC-222D/97/0117.
|Shimogaki, Y., How Low Dielectric Constant of F-Doped SiO2 Films can be obtained, DUMIC Conference paper, Feb. 10-11, 1997, ISMIC-222/D/97/0189.
|Sugahara, et al., Low Dielectric Constant Carbon Containing SiO2 Films Deposited by PECVD Technique Using a Novel CVD Precursor, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC-222D/97/0019, 19-25.
|Sugahara, et al., Low Dielectric Constant Carbon Containing SiO2 Films Deposited by PECVD Technique Using a Novel CVD Precursor, Feb. 10-11, 1997, DUMIC Conference, 1997 ISMIC—222D/97/0019, 19-25.
|Tamura, Takahiro, Preparation of Stable Fluorine-Doped Silicon Oxide Film by Biased Helicon Plasma CVD, DUMIC Conference paper, Feb. 20-21, 1996, ISMIC-111D/96/0231.
|Wang, B., Parylene-N Thermal Stability Increase by Oxygen Reductio-Low Substrate Temperature Depsotion, Preannealing and PETEOS Encapsulation, DUMIC Conference paper, Feb. 10-11, 1997, ISMIC-222D/97/0125.
|Wary, J., Vacuum-Deposited Parylene AF-4: A Thermally Stable, Low Dielectric Constant Polymer For Interlayer Dielectric Use, DUMIC Conference Paper, Feb. 20-21, 1996.
|Wary, John, Polymer Developed to be Interlayer Dielectric, Semiconductor International pp. 211-216, Jun. 1996.
|Citing Patent
|Filing date
|Publication date
|Mar 16, 2001
|Jul 27, 2004
|Tokyo Electron Limited
|Plasma deposition method and system
|May 18, 2000
|Aug 3, 2004
|Tokyo Electron Limited
|Method for forming film by plasma
|Feb 25, 2003
|Oct 19, 2004
|Applied Materials Inc.
|Method of depositing low K films
|Apr 29, 2005
|Sep 16, 2008
|Asm Japan K.K.
|Apparatus, precursors and deposition methods for silicon-containing materials
|Jun 25, 2010
|Jul 15, 2014
|Tokyo Electron Limited
|Plasma treatment method
|Mar 30, 2010
|Oct 6, 2015
|Tokyo Electric Limited
|Processing apparatus
|Feb 25, 2003
|Aug 28, 2003
|Applied Materials, Inc.
|Method of depositing low K films
|May 25, 2004
|Dec 23, 2004
|Lee Chung J.
|Reactor for producing reactive intermediates for low dielectric constant polymer thin films
|May 3, 2004
|Nov 3, 2005
|Bhatt Sanjiv M
|Fluorinated aromatic polymers
|May 23, 2006
|Sep 14, 2006
|Lee Chung J
|Reactor for Producing Reactive Intermediates for Transport Polymerization
|Apr 29, 2005
|Nov 2, 2006
|Todd Michael A
|Apparatus, precursors and deposition methods for silicon-containing materials
|May 31, 2006
|Dec 7, 2006
|Lee Chung J
|Substrate Holder
|Oct 17, 2006
|Nov 15, 2007
|Samsung Electronics Co., Ltd.
|Insulation film deposition method for a semiconductor device
|Jul 6, 2007
|Jan 17, 2008
|Accretech Usa, Inc.
|Method and apparatus for cleaning a wafer substrate
|Jul 6, 2007
|Jan 24, 2008
|Accretech Usa, Inc.
|Clean ignition system for wafer substrate processing
|Jul 6, 2007
|Aug 14, 2008
|Accretech Usa, Inc.
|Wafer processing apparatus and method
|Mar 30, 2010
|Mar 8, 2012
|Tokyo Electron Limited
|Processing apparatus
|Jun 25, 2010
|Nov 28, 2012
|Plasma treatment method
|Jun 25, 2010
|Jun 24, 2015
|Plasma treatment method
|Jun 25, 2010
|Dec 29, 2010
|Tokyo Electron Limited
|Plasma treatment method
|U.S. Classification
|International Classification
|Cooperative Classification
|European Classification
|Jul 28, 2003
Owner name: CANON U.S.A., INC., NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:QUESTER TECHNOLOGY, INC.;REEL/FRAME:013835/0049
Effective date: 20030728
Owner name: CANON U.S.A., INC., NEW YORK
Free format text: MERGER;ASSIGNOR:MERGER OF: QUESTER TECHNOLOGY, INC. INTO CANON USA, INC.;REEL/FRAME:013835/0056
Effective date: 20020117
|Sep 12, 2006
|Fee payment
Year of fee payment: 4
|Oct 25, 2010
|Maintenance fee reminder mailed
|Mar 18, 2011
|Lapse for failure to pay maintenance fees
|May 10, 2011
|Expired due to failure to pay maintenance fee
Effective date: 20110318


text:
Implant DentistryAre your teeth missing or broken beyond repair? If so, Implant Dentistry might be the perfect solution for you.
Implant Dentistry is the branch of dentistry that attaches permanent dental prostheses (crowns, bridges, partial dentures) directly onto or into the jaw bone. This process is done in order to replace missing teeth. With Implant Dentistry, an artificial root(s) is used to restore and support the replacement teeth.
There are many benefits to consider when determining if Implant Dentistry is right for you. When correctly cared for, dental implants can last much longer than traditional dental prostheses (such as crowns and bridgework), perhaps a lifetime. With Implant Dentistry, the replacements don't decay, fracture, or affect the natural teeth around them, and they actually stimulate bone growth and oral health.
Still, only you and your dentist can decide if they're the right choice for you. Contact our Rochester, NY dentists at Buhite & Buhite, DDS today to see if Implant Dentistry is right for you
Immediate implant in place at time of tooth removal
Immediate tooth removal, implant placed with temp crown and abutment

subset: commoncrawl


text:
MAHAndroidUpdater is library for notifing update information to installed android apps on android device.
This project makes a request to Play Store to check if there is a new version of your published app. Then, you can notify your users to do the update.
App to update to the latest version of WhatsApp for Android. Beta Updater for WhatsApp checks the latest beta version available on whatsapp.com and allows to install it automatically.
Android Library for checking the current uploaded version on the Google Play.
You can manage your application's version update or get your market information more simply.
Android Library that checks for updates on Google Play, GitHub or Amazon. This library notifies your apps' updates by showing a Material dialog, Snackbar or notification.
A library that checks for your apps updates on your own server.
Siren checks a user's currently installed version of your Android app against the latest version information stored in a JSON file on a server URL you provide.
Ota updater for unofficial roms.
Force your users to update the app, or notify about non-critical updates.
Update Checker For Google Play.
A library makes your application's auto update more elegant!
Framework for dispatching various procedure on update application.
An Android library that checks for your application's updates on Google Play Store. This library uses Android Publisher API.
Fresh Air is an application update library. It is designed to check a remote location for application updates and if updates are available, it prompts the user to upgrade the application. When the new version of the application is started, a dialog can be presented that showcases the new features to the user.
UpdateChecker is a class that can be used by Android Developers to increase the number of their apps' updates by showing a "New update available" Notification or Dialog.
When you publish new version android app, maybe you want all your application user update new version.


text:
Quick recap for me:
Friday was all about Metz. Defined the weekend for me. Screaming along on the rail while watching a totally blistering performance (best I've seen from them) was incredible. ...
Type: Posts; User: MissBellaHell
Quick recap for me:
Friday was all about Metz. Defined the weekend for me. Screaming along on the rail while watching a totally blistering performance (best I've seen from them) was incredible. ...
1. Anyone buy a deluxe upgrade and have opinions on whether it's worth it? Considering an impulse buy.
2. Looks like the weather is cooperating until Sunday.
Bahaha ok it's also a noun. But when it comes to humans, please use it as an adjective.
I use stitch fix. There's always been at least one thing that I've kept from the bunch. In fact, take my code and use it (I think we both get credits if so, just lmk if you want). It's pretty...
This annoys the shit out of me. Female is an adjective, people.
Boots are an excellent place to store cans of been in one's suitcase.
Lots of FYF/Psych Fest crossover.
You think DG is gonna show up? That's cute.
I'm just gonna roll off the plane tomorrow around midnight and show up at whatever bar y'all are at with my suitcase full of beer in tow.
Since I 100% don't care about either, I can make a nice clean exit from the fest during this conflict.
Agree. I *would* like to see more punk and hardcore but this isn't that festival anymore sadly.
FUCK - lots to like here. Edit: People are underwhelmed by this? I am like JAMC, Run the Jewels, Deerhunter, Savages, Dinosaur Jr., Joyce Manor, Melody's Echo Chamber, Metz, B&S, Spiritualized, Death...
Hat, dress, boots. I will be wet. Who gives a shit? MUSICS.
I'm not so worried about the weather. Warm and wet is way better than cold and wet. Just throw backup shoes and layers in the car and good to go. No?
We aren't?
People often talk over openers no matter who they are. When did she open for QOTSA?
Ugh. Not happy about that. Links to some songs that show me Chelsea is a decent replacement? What I'm hearing via quickly poking around Spotify is meh, though the Wiki/internet says she is...
PS - saw Lightning Bolt last night and I HIGHLY recommend checking them out. Probably gonna try to get right up front and check out the pit before heading to Spiritualized.
Austin Sog Fest 2015, you heard it here first. Looking forward to thunderstorms.
I mean, who cares, but all those above situations still would mean that you just use your credit card and pay it off later. If you don't want to carry a balance that's fine, but that's different...
Correct. Blew me away. Paying for it today (had to work in Ontario at 9am) but man. They should keep making music. Hope this isn't a one-off tour. No reason to think it is, of course. <3
I like the GOASTT one. At FFF I ended up stealing a poster off the Mohawk outside wall and taking it home. I wonder if the fest posters will be stealable around town.
I can't wait and I love the new song.
SK still play at 10:45?
That sweet tea vodka is DEADLY!! I apologize in advance for any drunkenness.
Hooray swings!
They responded to my email but not to my FB query.
You are an exceptional human being. Ok if I do donuts in the parking lot?
Thanks Nathan!! Can I go in and out to the car? I was mostly thinking about when it gets dark and I want to take off my hat and put on layers (sweater etc).
EDIT: suppose that makes no sense since...
ASP already got back to me. Lockers are only for camping. No one can pick up my wristband unless they have my paper ticket (and I have digi). Boooo
BTW I can't figure out the lockers thing - the site only talks about lockers for camping. Anyone figure this out yet? Also anyone know if you can pick up someone else's wristband? I've asked the...
Yeah Matt all those are on my list for sure. Not that big a fan of Indian Jewelry or Spindrift :(
When Andrew and I went to Riot Fest it was fucking 50 degrees and poured for 6 hours. That was...
This is mostly aspirational and I might need to flush out Sunday butttttttttt http://clashfinder.com/s/apf15/?user=hjcanning&
Yes planning on LA Witch, Las Robertas, Vaadat Chagrim and Creepoid. A quick study of Holydrug left me meh.
*Edit Gonna check out Holy Wave and Indian Jewelry too, in theory.
Anyone have opinions on the lower-billed acts? Now taking your recommendations.
*Edit: going through 'em quickly and White Manna and Hundred Visions sound pretty good.
Guysssssssssss I am excite. *EDIT brewery? IN.
Did that Clashfinder ever get made? Incidentally, Spiritualized is not predictable when it comes to shows. Giving Jason Pierce 1.5 hours is begging him to get pissed off and leave the stage early. ...
I'm officially in for this fest, sans Andrew :( But I just couldn't resist.
Viet Cong tonight yes? Who is going besides me and Jorge and Andrew?
No shit. I had this nice neat schedule - 4 appts, 10-12, half hour each. Then immediately two rescheduled for like 12:30 and 1. Those fuckers better show up.
I am displeased that I have to work in Palmdale (!!) Saturday morning, but hopefully will not miss much. I'll see y'all for hangover drinks Sunday though.
You obviously don't go there for authenticity, it's gringo Mexicano, but I work in Glendale and there's one right near my office. I'll totally eat the shit out of it. It has vegan meat, which is...
Andrew and I got some Pliny the Younger last night. It was of course delightful. I'm posting here because some dude I met in line told me about this place: http://maximilianohp.com/
Seems like gears might be useful for this, friend.
Also, Wurst is near Angel City Brewing and if people want to get growlers, that could be a thing.
We meeting at our house or at Wurst?
I will make guacamole you lucky mofos.
Yay! Music, vintage, Wurstkuche = my idea of a good time.
I saw Muse something like 3 times in 2004 (in small venues in and around Boston)for their Absolution tour and they were amazing. Saw them in Madison Square Garden for Black Holes and Revelations and...
What day do you usually do them? We're only free the 11th if it tends to be on a Saturday.


text:
Wego.com recently found 26 hotels in Sault Sainte Marie, Canada. Book last minute hotel or find great hotel deals such as Fairfield Inn & Suites Sault Ste. Marie for US$135 per night. Save more on cheap hotels with rates from as low as US$57 per night.
Filters help you save time when choosing where to stay. Try clicking on a few now...
Sault Sainte Marie Hotels 4 Star Hotels Sault Sainte Marie 3 Star Hotels Sault Sainte Marie Cheap Hotels Sault Sainte Marie Cheap Accommodation Sault Sainte Marie
Flights to Canada Flights from Canada Canada Airports Canada Airlines


text:
Asomdwe Park Opens To Public
The Asomdwe Park, the final resting place of the late President John Evans Atta Mills was on Sunday opened to the general public.
As at 09:30 hours when the Ghana News Agency (GNA) got to the Park, hundreds of Ghanaians and some foreigners were gathered in their numbers to catch a glimpse of the final resting place of the late President Mills.
In an interview with the GNA, Warrant Officer Class-One (Retired) Abubakari Nuhu, security officer in-charge of the Park disclosed that Dr Cadman Atta Mills, brother of the late President Mills was the first to visit the grave early Sunday morning.
WO1 Nuhu said the next person to visit the grave side was the National Security Coordinator, Lt. Col. Gbevlo Lartey, who prayed over the grave for some time before he left.
Members of the wider public from various religious, political and ethnic backgrounds were given access to the tomb of the departed leader where they moved around in a solemn mood.
They were also allowed to take photographs of the grave form a reasonable distance for their personal albums and not for commercial purposes.
President Mills died on July 24, 2012 at the 37 Military Hospital in Accra, three days after his 68th birthday.
He was laid to rest at the 'Asomdwe' Park last Friday, August 10, 2012, after a hugely attended funeral ceremony. The mourners included many foreign dignitaries..


text:
Santhali Shaadi
Santali Brides and Grooms
Matchfinder provides exclusive Santhali Shadi services for boys and girls from Santhali Community. We provide professional matrimonial services for Santhali people. We are offering free memberships on Santali Shaadi portal for a limited period. Sign up here to contact bridegrooms and girls instantly.
Register Now!


text:
(based on 49 reviews)
Ratings Distribution
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
of respondents would recommend this to a friend.
Best Uses
Reviewed by 49 customers
Displaying reviews 1-10
Back to top
Previous | Next »
Sturdier than it looks.
By TNUSAFRETVET
from ATOKA, TN
About Me Budget Shopper
Comments about Lap Table:
Bought for home use and possible use for my laptop (haven't used it for that as yet)..
Bottom Line Yes, I would recommend this to a friend
Was this review helpful? Yes / No
- You may also flag this review
sharp edges
By Tina
from nebraska
the edges are to sharp to rest arms on and it is very flimsy. I think a drink would spill in the cup holder.
Bottom Line No, I would not recommend this to a friend
(3 of 3 customers found this review helpful)
Not worth 2 cents!
By Mo
from Gilbert, AZ
About Me Midrange Shopper
I have an old lap tray from 40 yrs ago. Other than the hole that lets the styrofoam beads fall out, it beats this one hands down. The 1st time my husband used it was for a bowl of ice cream. As soon as he let go of the dish, it fell into the foot part of the recliner. What a mess! It's not heavy enough to stay on his lap like the other one is. It's totally useless but I'm not paying to send it back. Total waste of money! Print this - I dare 'ya!
(1 of 1 customers found this review helpful)
Lap Table
By Ginger
from Lathrup Village, MI
I use this mainly for writing. Would much prefer a smooth surface. Now put a piece of poster board under the paper I am using so writing is smooth. I do a lot of work in bed, and the concept is terrific. There is not nearly enough filling in the beanbag portion. It does not lay flat on my lap. I put a pillow underneath it to make it level. The idea is great, but needs some "tweeking".
It's just OK. I like other desktop item I have better.
By zenabuff
from Louisville, Ky
My mother likes more than I do because the nice cup holder, I like my wooden desk top better for working in a chair so much better. But it will work to say, eat lunch while watching TV. Or playing bridge if all parties had one. It would work will for playing solitaire, or just writing a simple note, as long as it isn't long.
don't like it. not well designed. Edge is hard on arms
By joanie
from florida
Sharp edges
By Elaine
from Wyoming
The edges are very sharp and hurt my arms if I rest them on the table. I'm trying to make a cover over the sharp parts of the edge. Not easy to do.
I would buy this product again and again.
By Super Granny
from Imperial, MO
I have bought 5 of these lap desks. The first one finally wore out.One came unglued, but the filling was bagged and did not leak. I could have used a hot glue gun to repair it, but it is so cheap that I chose to replace it. I keep 2 by my bed for writing and eating in bed. My grandchildren like to use it to eat in bed while watching tv. It has a cupholder. The surface is a little bumpy, so put something under letters if you use it for writing.
By Holly
from Arizona
Coloring, paying bills
(2 of 2 customers found this review helpful)
A little awkard
By mygard
from Pompton Plains, NJ
Need something firm under paper you are writing on as rough surface makes it difficult for pen or pencil to be legible


text:
There are a lot of questions about the NFL draft this week. So let's try to unravel some of the mysteries surrounding your favorite teams.
Darrek from Medina, Ohio writes: What are the chances the Cleveland Browns trade up to No. 4 to get safety Eric Berry?
James Walker: They are exploring it, Darrek. Berry and Oklahoma quarterback Sam Bradford are the only two players Cleveland would trade up to get, but it will cost them. I feel it's more likely the Browns use the No. 7 pick or move down.
David from Irbil, Iraq, writes: How likely is it that Cleveland will draft quarterback Dan LeFevour in the second round as opposed to Colt McCoy?
Walker: The Browns like McCoy more than LeFevour, David. So McCoy is the pick in this scenario. I'm pretty sure LeFevour isn't a strong candidate for Cleveland with the No. 38 overall pick. Maybe in the third round or lower if the Browns don't land a quarterback before then.
Ryan from La Crosse, WI, wants to know why there is so much trade talk leading up to the draft involving Baltimore Ravens left tackle Jared Gaither.
Walker: In my opinion some of the talk has been overstated, Ryan, as though it's 100-percent guaranteed Gaither will be traded. I'd say it's a possibility, but it's not a promise. Gaither received a first-round tender. So he has one year left on his contract and wants a huge extension. The Ravens believe right tackle Michael Oher has just as much potential, if not more, to play in Gaither's spot long-term. So there is some differing opinions there that might result in an eventual parting of ways--if not this year, then maybe next year.
QPD from Las Vegas, NV, wants to know if the Pittsburgh Steelers will draft a big running back like Ryan Mathews or Toby Gerhart.
Walker: Matthews is likely out of the question, because he's a first- or early second-round prospect and Pittsburgh's need there isn't that high. Gerhart could be a good fit--not only for the Steelers but in this division in general. Pittsburgh struggled to get tough yards, particularly in the red zone, and Gerhart would be a great value pick for them in the third round if he's still there.
Josh from Port of Spain, Trinidad, writes: With Cleveland trading for a corner and the disappointing 40 time of Florida's Joe Haden, do you see any scenario where he could fall to Pittsburgh at No. 18?
Walker: Sure, Josh. It happened in Monday's blogger mock draft. I told you I was a great general manager.
Blake from Dayton, OH, wants to know if the Cincinnati Bengals are candidates to trade picks to move up in the first or second round.
Walker: The Bengals are not a "trade up" team, Blake, especially in the first round. The contracts are so expensive in the top half of the first round that it's something Cincinnati wants to avoid. The lower the round, the better the possibility. So anything after the first round is not out of the question, despite it not being Cincinnati's track record.


text:
Smeg DC134L Freestanding Dishwasher, Silver
Product information
A flexible selection of programmes along with an A+ rating for energy and A ratings for wash and dry performance make the Smeg DC134L dishwasher an excellent addition to your kitchen.
A large 13 place settings capacity allows this dishwasher to easily handle the dishwashing needs of a large household, and is a very useful companion when you are hosting dinner parties! Other highlights include:
- Energysave with hot water
- Delay timer up to 9 hours provides convenience and means off-peak energy periods can be taken advantage of
- Daily quick programme suitable for a lightly soiled load
- Crystal cycle is particularly designed for delicate dishes with light dirt
- Strong and fast special programme takes less than an hour to eliminate stubborn dirt and dried on residues
- FlexiDuo baskets for cutlery
This Smeg appliance has a maximum noise level of just 43dB - so you can get on with your day while it quietly manages the washing up. A choice of 13 programmes allows you to wash according to your needs, and as it only uses just under 10 litres of water per standard cycle, you can be sure that your dishes are being washed efficiently.
- Adjustable racking Information Lets you move the racking around to fit large or awkward items
- Yes (upper baskets only)
- Automatic Load Adjustment Information Automatically adjusts water level for a smaller load, thus saving time and money
- Brand
- Delay Start
- Yes - up to 9 hours
- Digital display
- Dimensions
- H85 x W59.8 x D60
- Drying performance Information Graded on performance A - G, with A being the highest grade
- Energy Consumption Per Standard Cycle Information Based on the drying cycle of the standard cotton programme at full load. Actual energy consumption per cycle will depend on how the appliance is used.
- 1.03kWh/cycle
- Energy Rating Information Graded on performance, from A+++ to G, with A+++ being the highest rating. Higher ratings mean better energy efficiency
- Estimated Annual Energy Consumption Information Typical annual amount used by a 4 person household
- 292kWh/year
- Estimated Annual Water Consumption Information The amount of water used in litres per year, based on 220 standard washing cycles for cotton programs at 60°C and 40°C at full and partial load. Actual water consumption will depend on how the appliance is used.
- Model name / number
- Noise Level Information How noisy, in decibels, the machine is. The lower the dB, the quieter the appliance
- 43dB
- Number of Programs
- 13
- Overflow protection Information An anti-flood device prevents the machine from being damaged by flooding from the inlet pipe
- Place Settings Information A complete set of items provided for one person at a meal
- 13
- Program Sequence Indicator Information Tells you the progress of your washing/drying cycle
- Time remaining indicator Information Tells you how long the programme's got to go
- Type
- Freestanding
- Wash performance Information Graded on performance A - G, with A being the highest grade. The higher the grade the more energy efficient the appliance.
- Water Consumption Per Standard Cycle
UK delivery
- Delivery in 5 weeks from our supplier
International delivery not available
If you've changed your mind about keeping your purchase, please return it in its original condition with proof of purchase and we'll exchange or refund it. Unless faulty, this should be within 35 days of receiving your order. By original condition, we'd expect this to mean that you've kept packaging and labels, and that the item is undamaged and unused.
You can return for free in the UK via John Lewis shops, Royal Mail, Collect+ or MyHermes. If you need to arrange collection of large or heavy items, call us on 03456 049 049. For international returns queries, call us on +44 1698 545 454
You'll find returns information on your delivery note. Exceptions apply to certain products - find out more about our refund policy
Q & As
Wave farewell to the washing up with your new friend in the kitchen
UK deliveryFREE
Standard UK delivery within 5 weeks


text: News and events Latest news and forthcoming events from the School of Psychology. NewsRSS FeedAtom Feed Steve Mayhew receives award for brain fluctuations paper DescriptionDr Steve Mayhew, Birmingham Fellow in the School of Psychology, received the Neuroimage Editor's Choice Award in July for a paper investigating brain activity fluctuations.Date:26/08/2016 Researchers awarded an MRC grant of £98,000 DescriptionOrna Rosenthal, Chris Miall (School of Psychology) and David Punt (School of Sport, Exercise and Rehabilitation Sciences) were recently awarded an MRC Confidence in Concept grant of £98,000 to develop their methods for mapping upper limb motor performance after stroke.Date:10/08/2016 Best Publication Award for PhD Student DescriptionEva Reindl, third-year PhD student in the School of Psychology, has been awarded with The Michael K. O'Rourke Best Publication Award for the best PhD publication in the College of Life and Environmental Sciences 2016, receiving £400.Date:28/07/2016 EEG could indicate levels of awareness in a vegetative state DescriptionNew research suggests that an electroencephalogram (EEG) could be a strong indicator of the level of awareness of patients in a vegetative state after a severe brain injury.Date:27/07/2016 How the brain predicts the future DescriptionDr Massimiliano Di Luca and Dr Darren Rhodes have devised a model that takes into account past experience of the world to generate expectations for the future and have studied how it applies to time perception.Date:25/07/2016 PhD student takes part in Soapbox Science event DescriptionOn Saturday 18 June some of the country's top female academics took to the streets of Oxford to tell the public about their research. This event, run by Soapbox Science, was one of a series which aims to promote women in science in an interesting and engaging way as they share their passion for science with the general public.Date:21/07/2016 Overall Winner achievement award for PhD student DescriptionShana Gander-Zaucker, Doctoral Researcher in the School of Psychology, has won the Overall Winner achievement award, at the Graduate School's 10th annual Research Poster Conference. This year the event was held at the Aston Webb building at the University of Birmingham on 14 June.Date:18/07/2016 The key challenges facing UK policing today DescriptionIn a recent Birmingham Brief article, Dr Jessica Woodhams (School of Psychology) and Dr Siddhartha Bandyopadhyay (Department of Economics) discuss the challenges that criminal justice faces from society, and the areas of research on which the new Centre for Crime, Justice and Policing is focusing.Date:15/07/2016 Displaying 25 to 32 of 273 Previous … 2 3 4 5 6 … Next Events and seminarsRSS FeedAtom Feed There are no results that match your criteria. View forthcoming School seminars