Positive resist composition and pattern-forming method

A positive resist composition comprising:

• (A) a resin that has a repeating unit represented by general formula (a1) and increases its solubility in an alkali developer by action of an acid;
• (B) a compound which generates an acid upon irradiation with an actinic ray or a radiation;
• (C) a hydrophobic resin that has at least one of a fluorine atom and a silicon atom and has a group selected from the group consisting of (x), (y) and (z);
• and
• (D) a solvent:
• (x) an alkali-soluble group;
• (y) a group capable of decomposing by action of an alkali developer to undergo an increase in a solubility of the resin (C) in an alkali developer;
• and
• (z) a group that decomposes by action of an acid,
• wherein R represents a hydrogen atom or a methyl group, Rxa represents an alkyl group or a cycloalkyl group, and n represents an integer of 1 to 8;
• the weight average molecular weight of the resin (C) is from 2,000 to 15,000;
• the amount of the resin (C) is from 0.1 to 5% by weight based on the weight of the total solid components of the composition;
• the resin (A) contains a repeating unit containing a lactone structure;
• and
• a content of the repeating unit containing an acid decomposable group is 50 to 60 mol %, and a content of the repeating unit containing a lactone structure is 40 to 50 mol %, based on a total repeating units in the resin (A).

A positive resist composition comprising:

• (A) a resin that has a repeating unit represented by general formula (a1) and increases its solubility in an alkali developer by action of an acid;
• (B) a compound which generates an acid upon irradiation with an actinic ray or a radiation;
• (C) a hydrophobic resin that has at least one of a fluorine atom and a silicon atom and has a group selected from the group consisting of (x), (y) and (z);
• and
• (D) a solvent:
• (x) an alkali-soluble group;
• (y) a group capable of decomposing by action of an alkali developer to undergo an increase in a solubility of the resin (C) in an alkali developer;
• and
• (z) a group that decomposes by action of an acid,
• wherein R represents a hydrogen atom or a methyl group, Rxa represents an alkyl group or a cycloalkyl group, and n represents an integer of 1 to 8;
• the weight average molecular weight of the resin (C) is from 2,000 to 15,000;
• the amount of the resin (C) is from 0.1 to 5% by weight based on the weight of the total solid components of the composition;
• the acid generator (B) is a compound represented by formula (ZI):
• wherein R201 to R203 each independently represent an organic group and X— is a sulfonate anion represented by the following formula:
• wherein Rc1 in the sulfonate anion is an alkyl group substituted by a fluorine atom or a fluoroalkyl group at 1-position and includes a cycloalkyl group.

A resist film, comprising:

• (A) a resin that has a repeating unit represented by general formula (a1) and increases its solubility in an alkali developer by action of an acid;
• (B) a compound which generates an acid upon irradiation with an actinic ray or a radiation;
• and
• (C) a hydrophobic resin that has at least one of a fluorine atom and a silicon atom and has a group selected from the group consisting of (x), (y) and (z):
• (x) an alkali-soluble group;
• (y) a group capable of decomposing by action of an alkali developer to undergo an increase in a solubility of the resin (C) in an alkali developer;
• and
• (z) a group that decomposes by action of an acid,
• wherein R represents a hydrogen atom or a methyl group, Rxa represents an alkyl group or a cycloalkyl group, and n represents an integer of 1 to 8;
• the weight average molecular weight of the resin (C) is from 2,000 to 15,000;
• the amount of the resin (C) is from 0.1 to 5% by weight based on the weight of the total solid components of the composition;
• and
• the resin (A) contains a monocyclic lactone structure.

A resist film, comprising:

• (A) a resin that has a repeating unit represented by general formula (a1) and increases its solubility in an alkali developer by action of an acid;
• (B) a compound which generates an acid upon irradiation with an actinic ray or a radiation;
• and
• (C) a hydrophobic resin that has at least one of a fluorine atom and a silicon atom and has a group selected from the group consisting of (x), (y) and (z):
• (x) an alkali-soluble group;
• (y) a group capable of decomposing by action of an alkali developer to undergo an increase in a solubility of the resin (C) in an alkali developer;
• and
• (z) a group that decomposes by action of an acid,
• wherein R represents a hydrogen atom or a methyl group, Rxa represents an alkyl group or a cycloalkyl group, and n represents an integer of 1 to 8;
• the weight average molecular weight of the resin (C) is from 2,000 to 15,000;
• the amount of the resin (C) is from 0.1 to 5% by weight based on the weight of the total solid components of the composition;
• the resin (A) contains a repeating unit containing a lactone structure;
• and
• a content of the repeating unit containing an acid decomposable group is 50 to 60 mol %, and a content of the repeating unit containing a lactone structure is 40 to 50 mol %, based on a total repeating units in the resin (A).

A resist film comprising:

• (A) a resin that has a repeating unit represented by general formula (a1) and increases its solubility in an alkali developer by action of an acid;
• (B) a compound which generates an acid upon irradiation with an actinic ray or a radiation;
• and
• (C) a hydrophobic resin that has at least one of a fluorine atom and a silicon atom and has a group selected from the group consisting of (x), (y) and (z):
• (x) an alkali-soluble group;
• (y) a group capable of decomposing by action of an alkali developer to undergo an increase in a solubility of the resin (C) in an alkali developer;
• and
• (z) a group that decomposes by action of an acid,
• wherein R represents a hydrogen atom or a methyl group, Rxa represents an alkyl group or a cycloalkyl group, and n represents an integer of 1 to 8;
• the weight average molecular weight of the resin (C) is from 2,000 to 15,000;
• the amount of the resin (C) is from 0.1 to 5% by weight based on the weight of the total solid components of the composition;
• the acid generator (B) is a compound represented by formula (ZI):
• wherein R201 to R203 each independently represent an organic group and X— is a sulfonate anion represented by the following formula:
• wherein Rc1 in the sulfonate anion is an alkyl group substituted by a fluorine atom or a fluoroalkyl group at 1-position and includes a cycloalkyl group.