Resist composition for immersion exposure and pattern formation method using the same

1. A pattern formation method comprising:

providing a resist composition for immersion, comprising:

(A) a resin of which solubility in an alkali developer increases under an action of an acid;

(B) a photoacid generator; and

(C) a mixed solvent containing an alkylene glycol alkyl ether carboxylate and a propylene glycol monomethyl ether;

coating the resist composition on a substrate to form a resist film; and

immersion exposing the resist film,

wherein the resin (A) comprises a repeating unit represented by the following formula (AII):

wherein R 1c represents a hydrogen atom or a methyl group, and R 2c to R 4c each independently represents a hydrogen atom or a hydroxyl group, provided that at least two of R 2c to R 4c represent a hydroxyl group.

2. The pattern formation method according to claim 1 , wherein an immersion liquid used in the immersion exposing comprises water.

3. The pattern formation method according to claim 1 , wherein a mixing ratio by mass of the mixed solvent (C) is alkylene glycol alkyl ether carboxylate/propylene glycol monomethyl ether=4/6 to 9/1.

4. The pattern formation method according to claim 1 , wherein a mixing ratio by mass of the mixed solvent (C) is alkylene glycol alkyl ether carboxylate/propylene glycol monomethyl ether=4.5/5.5 to 8.5/1.5.

5. The pattern formation method according to claim 1 , wherein a mixing ratio by mass of the mixed solvent (C) is alkylene glycol alkyl ether carboxylate/propylene glycol monomethyl ether=5/5 to 8/2.

6. The pattern formation method according to claim 1 , wherein a mixing ratio by mass of the mixed solvent (C) is alkylene glycol alkyl ether carboxylate/propylene glycol monomethyl ether=6/4 to 7.5/2.5.

7. The pattern formation method according to claim 1 , wherein the resist composition further comprises (E) a surfactant.

8. The pattern formation method according to claim 7 , wherein the surfactant comprises at least one of: a fluorine-containing surfactant; a silicon-containing surfactant; and a fluorine/silicon-containing surfactant.

9. A pattern formation method comprising:

providing a resist composition for immersion, comprising:

(A) a resin of which solubility in an alkali developer increases under an action of an acid;

(B) a photoacid generator; and

(C) a mixed solvent containing an alkylene glycol alkyl ether carboxylate and a propylene glycol monomethyl ether;

coating the resist composition on a substrate to form a resist film; and

immersion exposing the resist film,

wherein the immersion liquid used in the immersion exposure comprises water and an aliphatic alcohol having a refractive index substantially equal to that of water.