Positive resist composition and pattern formation method using the same

Abstract

A positive resist composition containing a compound including a sulfonium cation having a structure represented by the formula (Z-I) as defined herein, a low molecular weight compound which increases solubility in an alkali developing solution by an action of an acid, and a compound which generates a compound having a structure represented by the formula (A-I) as defined herein upon irradiation of an actinic ray or a radiation.

Description

Claims

1. A positive resist composition comprising: a compound including a sulfonium cation having a structure represented by the following formula (Z-I);a low molecular weight compound which increases solubility in an alkali developing solution by an action of an acid; anda compound which generates a compound having a structure represented by the following formula (A-I) upon irradiation of an actinic ray or a radiation:

2. The positive resist composition as claimed in claim 1, wherein the low molecular weight compound is a compound having a structure represented by the following formula (T-I):

3. The positive resist composition as claimed in claim 2, wherein the compound having a structure represented by the formula (T-I) is a compound having a structure represented by one of the following formulae (T-II) to (T-IV):

4. The positive resist composition as claimed in claim 1, wherein the low molecular weight compound is a compound having a structure represented by the following formula (T-V):

5. The positive resist composition as claimed in claim 1, wherein the compound which generates a compound having a structure represented by the formula (A-I) upon irradiation of an actinic ray or a radiation is a sulfonium salt compound of the compound having a structure represented by the formula (A-I) or an iodonium salt compound of the compound having a structure represented by the formula (A-I).

6. The positive resist composition as claimed in claim 2, wherein the compound which generates a compound having a structure represented by the formula (A-I) upon irradiation of an actinic ray or a radiation is a sulfonium salt compound of the compound having a structure represented by the formula (A-I) or an iodonium salt compound of the compound having a structure represented by the formula (A-I).

7. The positive resist composition as claimed in claim 3, wherein the compound which generates a compound having a structure represented by the formula (A-I) upon irradiation of an actinic ray or a radiation is a sulfonium salt compound of the compound having a structure represented by the formula (A-I) or an iodonium salt compound of the compound having a structure represented by the formula (A-I).

8. The positive resist composition as claimed in claim 4, wherein the compound which generates a compound having a structure represented by the formula (A-I) upon irradiation of an actinic ray or a radiation is a sulfonium salt compound of the compound having a structure represented by the formula (A-I) or an iodonium salt compound of the compound having a structure represented by the formula (A-I).

9. A resist pattern formation method comprising: coating the positive resist composition as claimed in claim 1 on a substrate to form a resist film;exposing the resist film; anddeveloping the exposed resist film to form a resist pattern.