Positive type resist composition

1. A positive resist composition comprising:

(A) a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, which increases its solubility in an alkali developing solution by the action of an acid;

(B) a compound capable of generating an acid upon irradiation with an actinic ray or actinic radiation; and

(C) an alkoxy alcohol as a solvent, wherein an alkoxy group and an alcoholic hydroxyl group are connected to each other via at least three carbons,

wherein the resin (A) comprises a repeating unit having an alkali-soluble group protected by a 2-alkyl-2-adamantyl group or a 1-adamantyl-1-alkylalkyl group.

2. The composition according to claim 1 , wherein the solvent (C) further contains a propylene glycol monoalkyl ether carboxylate.

3. The composition according to claim 2 , wherein the solvent (C) contains from 10 to 50% by weight of the alkoxy alcohol and from 50 to 90% by weight of the propylene glycol monoalkyl ether carboxylate.

4. The composition according to claims 1 , wherein the alkoxy alcohol is 3-methoxybutanol.

5. The composition according to claim 2 , wherein the propylene glycol monoalkyl ether carboxylate is propylene glycol monomethyl ether acetate.

6. The composition according to claim 1 , wherein the resin (A) comprises a repeating unit having a group represented by the following formula (I):

wherein R 2c , R 3c , and R 4c each independently represents a hydrogen atom or a hydroxyl group, provided that at least one of R 2c , R 3c , and R 4c represents a hydroxyl group.

7. The composition according to claim 1 , wherein the compound (B) is a compound capable of generating a perfluorobutanesulfonic acid or a perfluorooctanesulfonic acid upon irradiation with an actinic ray or a radiation.

8. The composition according to claim 1 , wherein the alkoxy group and the alcoholic hydroxyl group are connected to each other via from 3 to 10 carbons.

9. The composition according to claim 1 , wherein the alkoxy alcohol has a boiling point of from 120 to 220° C.

10. The composition according to claim 1 , further comprising (D) a nitrogen-containing basic compound.

11. The composition according to claim 1 , further comprising (E) a fluorine based and/or silicon based surfactant.

12. A method for forming a pattern, which comprises forming a resist film comprising the composition described in claim 1 , exposing the resist film upon irradiation with the actinic rays or a radiation, and subsequently developing the resist film.