Positive photoresist composition and pattern making method using the same

1. A positive photoresist composition containing:

(A) a resin which contains at least one of a repeating unit represented by the formula (IA) and a repeating unit represented by the formula (IB), and is decomposed by an action of an acid and shows an increase in a solubility in an alkali developer; and

(B) as compounds capable of generating an acid upon irradiation with one of an actinic ray and a radiation, at least two compounds selected from the group consisting of:

(B1) a compound capable of generating an aliphatic or aromatic sulfonic acid substituted by at least one fluorine atom upon irradiation with one of an actinic ray and a radiation;

(B2) a compound capable of generating an aliphatic or aromatic sulfonic acid containing no fluorine atom upon irradiation with one of an actinic ray and a radiation;

(B3) a compound capable of generating an aliphatic or aromatic carboxylic acid substituted by at least one fluorine atom upon irradiation with one of an actinic ray and a radiation; and

(B4) a compound capable of generating an aliphatic or aromatic carboxylic acid containing no fluorine atom upon irradiation with one of an actinic ray and a radiation;

wherein Ra, Rb and Rc each independently represents a hydrogen atom, a methyl group, a fluorine atom or a fluoroalkyl group;

n is 0 or 1;

Y represents a fluorine atom or a fluoroalkyl group;

u is an integer of from 1 to 5;

L and M each independently represents a methylene group, an oxygen atom or an ester group; and

R 11 to R 16 each independently represents a hydrogen atom, a fluorine atom or a fluoroalkyl group, provided that at least one of R 11 to R 16 represents a fluorine atom or a fluoroalkyl group.

2. The photoresist composition according to claim 1 , wherein the resin (A) contains at least one of a repeating unit represented by the following formula (IIA) and a repeating unit represented by the following formula (IIB):

wherein Ra, Rb and Rc each independently represents a hydrogen atom, a methyl group, a fluorine atom or a fluoroalkyl group;

AR represents an alicyclic hydrocarbon structure;

p is an integer of from 1 to 5; and

Rg and Rh each independently represents a hydrogen atom, a hydroxyl group or a hydroxyalkyl group, provided that at least one of Rg and Rh represents a hydroxyl group or a hydroxyalkyl group.

3. The photoresist composition according to claim 1 , wherein the resin (A) further contains at least one of repeating units represented by the following formulae (VIII) to (XVII):

wherein R 25 , R 26 and R 27 may be same or different and each represents a hydrogen atom, a fluorine atom, an alkyl group, a cycloalkyl group or an aryl group; R 28 , R 29 and R 30 may be same or different and each represents an alkyl group, a cycloalkyl group or an aryl group; or R 25 and R 26 , R 27 and R 28 , or R 29 and R 30 may be bonded to each other to form a ring; R 31 , R 37 , R 40 and R 44 may be same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group, an acyl group or an alkoxycarbonyl group; R 41 , R 42 and R 43 may be same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group; R 36 and R 39 may be same or different and each represents a hydrogen atom, a halogen atom, a cyano group or an alkyl group; R 38 represents an alkyl group, a cycloalkyl group, an aralkyl group or an aryl group; B 1 and B 2 represent each a single bond or a divalent linking group; B 3 represents a divalent linking group; n is 0 or 1;

Rk1, Rk2 and Rk3 each independently represents a halogen atom, an alkyl group or an alkoxy group;

X 1 represents a hydrogen atom or a monovalent organic group;

1a is 0 or 1; 1b is an integer of 0 to 2; and 1c is an integer of 0 to 5.

4. The photoresist composition according to claim 1 , further containing (D) a surfactant containing at least one of a fluorine atom and a silicone atom.

5. The photoresist composition according to claim 1 , further containing (E) a basic compound having a nitrogen atom.

6. The photoresist composition according to claim 1 , for using in F 2 laser irradiation.

7. A pattern making method comprising forming a resist film by using the photoresist composition according to claim 1 , exposing the resist film and developing.