Salt and photoresist composition containing the same
A salt containing a group represented by the formula (aa): wherein X a and X b independently each represent an oxygen atom or a sulfur atom, a ring W represents a C3-C18 heterocycle which has a carbonate ester structure and which can have a substituent, and * represents a binding position is provided.
1. A salt comprising an anion represented by formula (aa2):
wherein X a and X b independently each represent an oxygen atom or a sulfur atom,
a ring W represents a C3-C18 heterocycle which has a carbonate ester structure and which can have a substituent,
a ring W1 represents a C3-C18 non-aromatic hydrocarbon ring which can have a substitute and in which a methylene group can be replaced by —O—, —S—, —CO— or —SO 2 —,
L 1 represents a C1-C24 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a fluorine atom or a hydroxyl group and in which a methylene group can be replaced by —O— or —CO—, and
Q 1 and Q 2 independently each represent a fluorine atom or a C1-C6 perfluoroalkyl group.
2. The salt according to claim 1 ,
wherein the ring W1 represents an adamantane ring or a cyclohexane ring.
3. The salt according to claim 1 ,
wherein L 1 is represented by formula (b1-1) or (b1-2):
in which L b2 represents a single bond or a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a fluorine atom; L b3 represents a single bond or a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and where a methylene group may be replaced by an oxygen atom or carbonyl group, provided that total number of the carbon atoms of L b2 and L b3 is up to 22;
L b4 represents a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a fluorine atom; and L b5 represents a single bond or a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and where a methylene group may be replaced by an oxygen atom or carbonyl group, provided that the total carbon atoms of L b4 and L b5 is up to 22.
4. An acid generator comprising the salt according to claim 1 .
5. A photoresist composition comprising the acid generator according to claim 4 and a resin which comprises a structural unit having an acid-labile group.
6. The photoresist composition according to claim 5 further comprises a salt generating an acid weaker in acidity than an acid generated from the acid generator.
7. A process for producing a photoresist pattern comprising the following steps (1) to (5):
(1) a step of applying the photoresist composition according to claim 5 or 6 on a substrate,
(2) a step of forming a composition film by conducting drying,
(3) a step of exposing the composition film to radiation,
(4) a step of baking the exposed composition film, and
(5) a step of developing the baked composition film thereby forming a photoresist pattern.
8. A salt comprising a group represented by the formula (aa):
wherein X a and X b independently each represent an oxygen atom or a sulfur atom,
a ring W represented 1,3-dioxan-2-one ring, and
* represents a binding position.
9. The salt according to claim 8 , which comprises a cation and an anion having the group represented by formula (aa).
10. The salt according to claim 9 , wherein the anion having the group represented by formula (aa) is a sulfonate anion.
11. The salt according to claim 8 , which has a group represented by formula (aa1):
wherein X a , X b the ring W and * are as defined in claim 8 ,
a ring W1 represents a C3-C18 non-aromatic hydrocarbon ring which can have a substituent and in which a methylene group can be replaced by —O—, —S—, —CO— or —SO 2 —.
12. The salt according to claim 11 , which has an anion represented by formula (aa2):
wherein X a , X b , the ring W and the ring W1 are as defined in claim 11 ,
L 1 represents a C1-C24 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a fluorine atom or a hydroxyl group and in which a methylene group can be replaced by —O— or —CO—, and
Q 1 and Q 2 independently each represent a fluorine atom or a C1-C6 perfluoroalkyl group.
13. The salt according to claim 12 ,
wherein the ring W1 represents an adamantane ring or a cyclohexane ring.
14. The salt according to claim 12 ,
wherein L 1 is represented by formula (b1-1) or (b1-2):
in which L b2 represents a single bond or a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a fluorine atom; L b3 represents a single bond or a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and where a methylene group may be replaced by an oxygen atom or carbonyl group, provided that total number of the carbon atoms of L b2 and L b3 is up to 22;
L b4 represents a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a fluorine atom; and L b5 represents a single bond or a C1-C22 divalent saturated hydrocarbon group where a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and where a methylene group may be replaced by an oxygen atom or carbonyl group, provided that the total carbon atoms of L b4 and L b5 is up to 22.
15. An acid generator comprising the salt according to claim 8 .
16. A photoresist composition comprising the acid generator according to claim 15 and a resin which comprises a structural unit having an acid-labile group.
17. The photoresist composition according to claim 16 , which further comprises a salt generating an acid weaker in acidity than an acid generated from the acid generator.
18. A process for producing a photoresist pattern comprising the following steps (1) to (5):
(1) a step of applying the photoresist composition according to claim 16 or 17 on a substrate,
(2) a step of forming a composition film by conducting drying,
(3) a step of exposing the composition film to radiation,
(4) a step of baking the exposed composition film, and
(5) a step of developing the baked composition film thereby forming a photoresist pattern.