US 8,637,222 B2  7  8  methyl ethyl ketone, methyl amyl ketone, methyl isobutyl  ketone, acetyl acetone, acetonyl acetone, ionone, diacetonyl  alcohol, acetyl carbinol, acetophenone, methyl naphthyl  ketone, isophorone and propylene carbonate. Among these,  an alkyl ketone-based solvent such as methyl isobutyl ketone,  methyl amyl ketone, cyclopentanone and cycloheptane is  preferred.  Examples of the alcohol-based solvent include an alcohol  such as methyl alcohol, ethyl alcohol, n-propyl alcohol, iso› propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl  alcohol, isobutyl alcohol, hexyl alcohol (e.g., n-hexyl alco› hol), heptyl alcohol (e.g., n-heptyl alcohol), octyl alcohol  ( e.g., n-octyl alcohol) and decanol ( e.g., n-decanol); a glycol› based solvent such as ethylene glycol, diethylene glycol,  triethylene glycol, 1,2-propylene glycol, 1,3-propylene gly› col, 1,2-butylene glycol, 1,3-butylene glycol and 1,4-buty› lene glycol; an alkylene glycol monoalkyl ether-based sol› vent such as ethylene glycol monomethyl ether, propylene  glycol monomethyl ether (PGME; another name: 1-methoxy- 2-propanol), ethylene glycol monoethyl ether, propylene gly› col monoethyl ether, di ethylene glycol monomethyl ether and  triethylene glycol monoethyl ether; a glycol ether-based sol› vent such as methoxymethyl butanol and propylene glycol  dimethyl ether; and a phenol-based solvent such as phenol  and cresol. Among these, 1-hexanol, 2-hexanol, 1-octanol,  2-ethyl-hexanol, propylene glycol monomethyl ether and  cresol are preferred.  Examples of the amide-based solvent which can be used  include N-methyl-2-pyrrolidone, N,N-dimethylacetamide,  N,N-dimethylformamide, hexamethylphosphoric triamide  and 1,3-dimethyl-2-imidazolidinone.  Examples of the ether-based solvent include, in addition to  the alkylene glycol monoalkyl ether-based solvents and gly- col ether-based solvents above, dioxane, tetrahydrofuran and  tetrahydropyran.  Examples of the hydrocarbon-based solvent include an  aromatic hydrocarbon-based solvent such as toluene and  xylene, and an aliphatic hydrocarbon-based solvent such as  pentane, hexane, octane, decane and dodecane.  The developer preferably contains one or more kinds of  solvents selected from an alkylene glycol monoalkyl ether  carboxylate-based solvent, an alkylene glycol monoalkyl  ether-based solvent, an alkyl carboxylate-based solvent and  an alkyl ketone-based solvent, more preferably one or more  kinds of solvents selected from propylene glycol monom› ethyl ether, propylene glycol monomethyl ether acetate,  methyl isobutyl ketone, methyl amyl ketone, cyclopentanone,  cyclohexanone, ethyl lactate and butyl acetate.  The developer is preferably a developer containing at least  one kind of an organic solvent selected from the group con› sisting of an ester-based solvent containing no hydroxyl  group in the molecule, a ketone-based solvent containing no  hydroxyl group in the molecule, and an ether-based solvent  containing no hydroxyl group in the molecule.  More specifically, the developer is preferably a developer  containing an organic solvent that does not contain a hydroxyl  group in the molecule, represented by any one of the follow- ing formulae (Sl) to (S3):  -continued  In formulae (S 1) to (S3 ), each of R and R’ independently  represents an alkyl group, a cycloalkyl group, an alkoxyl  group, an alkoxycarbonyl group, a cyano group or a halogen  atom. The carbon number of the alkyl group, cycloalkyl  group, alkoxy group and alkoxycarbonyl group is usually  from 1 to 6. Rand R’ may combine with each other to form a  ring (preferably a 5- or 6-membered ring). These groups and  the ring formed by combining R and R’ with each other may  be further substituted by a carbonyl group-containing group  (e.g., acyl, aldehyde), a cyano group, an alkoxy group, an  alkyl ester group or the like.  The organic solvent having no hydroxyl group in the mol› ecule is preferably an ester-based solvent such as methyl  acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl  acetate, ethyl-3-ethoxypropionate, propylene glycol diac› etate, 3-methoxybutyl acetate and 3-methyl-3-methoxybutyl  acetate, a ketone-based solvent other than a ketone-based  solvent having a hydroxyl group in the molecule, such as  diacetonyl alcohol and acetyl carbinol, out of the above› described ketone-based solvents, or an ether-based solvent  such as dioxane, tetrahydrofuran and tetrahydropyran, and it  is more preferred to contain one or more members selected  from methyl isobutyl ketone, methyl amyl ketone, cyclohex- anone and butyl acetate.  A plurality of these solvents may be mixed, or the solvent  may be mixed with a solvent other than those described above  or with water.  The concentration of the organic solvent (in the case of  mixing a plurality of solvents, the total concentration) in the  developer is preferably 50 mass % or more, more preferably  70 mass % or more, still more preferably 90 mass % or more.  It is particularly preferred that the developer is substantially  composed of only an organic solvent. Here, the expression  "substantially composed of only an organic solvent" includes  a case where the developer contains a small amount of a  surfactant, an antioxidant, a stabilizer, a defoaming agent or  the like.  The percentage of water content in the developer is pref› erably 10 mass % or less, more preferably 5 mass % or less,  still more preferably 3 mass% or less, and it is most preferred  to contain substantially no water. By virtue of setting the  percentage of water content to 10 mass % or less, good  development characteristics can be obtained.  Surfactant:  In the developer containing an organic solvent, an appro› priate amount of a surfactant can be added, if desired.  As for the surfactant, the same as the later-described sur› factant used in the resist composition may be used.  The amount of the surfactant used is usually from 0.001 to  5 mass %, preferably from 0.005 to 2 mass %, more prefer› ably from 0.01 to 0.5 mass %, based on the entire amount of  the developer.  Developing Method:  As regards the developing method, for example, a method  of dipping the substrate in a bath filled with the developer for  a fixed time ( dipping method), a method of raising the devel- aper on the substrate surface by the effect of a surface tension  and keeping it still for a fixed time, thereby performing the  development (puddle method), a method of spraying the  (S1)  (S2)  0  R_JLR’  (S3)  R-0-R’ 