60  59  US 9,513,547 B2  After preparing the film and before the exposing, a  prebake process (PB; Prebake) is also preferably included.  In addition, after the exposing and before the developing,  heating (PEB; Post Exposure Bake) is also preferably  included.  Regarding the heating temperature, heating of any of PB  and PEB is preferably at a temperature of 70 to 130°  C., and  more preferably at a temperature of 80 to 120°  C.  The heating time is preferably 30 to 300 seconds, more  preferably 30 to 180 seconds, and still more preferably 30 to  90 seconds.  Heating may be carried out by a unit included in a normal  exposure/development apparatus, and may also be carried  out using a hot plate or the like.  By the baking, the reaction of the exposed portion is  accelerated and the sensitivity or pattern profile is improved.  Examples of the wavelength of the light source used in the  exposure apparatus of the invention include a KrF excimer  laser (248 nm), an EUV (13 nm), an electron beam, or the  like, and a KrF excimer laser is preferred.  In the invention, the substrate on which the film is formed  is not particularly limited, and a substrate generally used for  lithography in the production of a semiconductor device  such as an IC, a liquid crystal device or a circuit board such  as a thermal head and further in other photo-fabrication  processes, such as an inorganic substrate, for example,  silicon, SiN, SiO$_{2}$ ,  and SiN and a coating-type inorganic  substrate, for example, SOG, can be used.  The pattern forming method of the invention can use an  uneven substrate as the substrate in the fine processing such 30  as usage in ion implantation, for example.  For example, in a case of fine processing such as usage in  ion implantation, a substrate in which fins and gates are  patterned on a flat substrate can be used as the uneven  substrate. The film thickness of the resist film coated with  the actinic ray-sensitive or radiation-sensitive resin compo› sition and formed on the uneven substrate patterned with fins  and gates in this manner refers to the height from the bottom  surface on the uneven substrate as described above to the top  surface of the formed resist film, not to the height from the  upper surface of the fins or gates to the upper surface of the  formed resist film.  As the size (width, length, height, or the like), spacing,  structure, configuration, or the like, of the fins and gates, for  example, the ones described in pages 25 to 29 of "Cutting› edge FinFET processing and integration technology" Jour› nal of the institute of Electronics, Information and Commu› nication Engineers Vol. 91 No. 1 2008, or Jpn. J. Appl. Phys.  Vol. 42 (2003) pp. 4142-4146 Part 1 No. 6B June 2003  "Fin-Type Double-Gate Metal-Oxide-Semiconductor Field› Effect Transistors Fabricated by Orientation-Dependent  Etching and Electron Beam Lithography" can be appropri› ately applied.  The pattern forming method of the invention does not  require an antireflection film from the viewpoint of achiev› ing the effect of the invention; however, an organic antire› flection film may be formed between the film and the  substrate as necessary.  For example, the antireflection film may be provided at  the lower layer of the resist. The antireflection film used may  be either an inorganic film type such as titanium, titanium  dioxide, titanium nitride, chromium oxide, carbon or amor› phous silicon, or an organic film type formed of a light  absorber and a polymer material. In the former case, the  provision of a vacuum deposition apparatus, a CVD appa- ratus, a sputtering apparatus, or the like is necessary in the  film forming. As the organic antireflection film, examples  Examples of the ether-based solvent include, in addition  to the glycol ether-based solvents above, dioxane, and  tetrahydrofuran.  Examples of the alcohol-based solvent include alcohols  such as methyl alcohol, ethyl alcohol, n-propyl alcohol,  isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert› butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl  alcohol, n-octyl alcohol and n-decanol; glycol-based sol› vents such as ethylene glycol, diethylene glycol, and trieth› ylene glycol; and glycol ether-based solvents such as eth- ylene  glycol  monomethyl  ether,  propylene  glycol  monomethyl ether, ethylene glycol monoethyl ether, propyl› ene glycol monoethyl ether, diethylene glycol monomethyl  ether, triethylene glycol monoethyl ether, and methoxym- ethyl butanol.  Examples of the ester-based solvent include methyl  acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl  acetate, isopentyl acetate, amyl acetate, propylene glycol  monomethyl ether acetate, ethylene glycol monoethyl ether  acetate, diethylene glycol monobutyl ether acetate, diethyl› ene glycol monoethyl ether acetate, ethyl-3-ethoxypropi- onate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl  acetate, methyl formate, ethyl formate, butyl formate, propyl  formate, ethyl lactate, butyl lactate, and propyl lactate.  Examples of the ketone-based solvent include 1-octanone,  2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone  (methyl  amyl  ketone),  4-heptanone,  1-hexanone,  2-hexanone, diisobutyl ketone, cyclohexanone, methylcy- clohexanone, phenyl acetone, methylethyl ketone, methyl  isobutyl ketone, acetylacetone, acetonylacetone, ionone,  diacetonyl alcohol, acetylcarbinol, acetophenone, methyl  naphthyl ketone, isophorone, and propylene carbonate.  As the developer (hereinafter also referred to as an  organic developer) in the development with a developer  including an organic solvent in the pattern forming method  of the invention, a polar solvent such as a ketone-based  solvent, an ester-based solvent, an alcohol-based solvent, an  amide-based solvent, and an ether-based solvent, or a hydro- carbon-based solvent may be used.  Examples of the antireflection film include AQUATAR-II,  AQUATAR-III, AQUATAR-VII, and the like manufactured  by AZ Electronic Materials Corp.  In addition, as necessary, the antireflection film can be  used on the upper layer of the resist.  In addition, as the organic antireflection film, a commer- cially available organic antireflection film such as DUV30  Series and DUV-40 Series manufactured by Brewer Science,  Inc. and AR-2, AR-3 and AR-5 manufactured by Shipley  Co., Ltd. can also be used.  include ones formed of a condensate of a diphenylamine  derivative and a formaldehyde modified melamine resin, an  alkali-soluble resin, and a light-absorbing agent described in  JP1995-69611B (JP-H07-69611B); a reactant of a maleic  anhydride copolymer and a diamine type light-absorbing  agent described in U.S. Pat. No. 5,294,680A; ones contain› ing a resin binder and a methylol melamine-based heat  cross-linking agent described in JP1994-118631A (JP-H06- 118631A); an acrylic resin-type antireflection film having a  carboxylic acid group, an epoxy group, and a light-absorb› ing group in the same molecule described in JP1994- 118656A (JP-H06-118656A); ones formed of methylol  melamine and a benzophenone-based light-absorbing agent  described in JP! 996-8711  SA  (JP-H08-87115A); and ones in  which a low molecular weight light-absorbing agent is  attached to a polyvinyl alcohol resin described in JP1996- 179509A (JP-H08-l 79509A); 