Salt, acid generator, resist composition and method for producing resist pattern

Patent metadata

Field	Value
Publication number	US-11467490-B2
Application number	US-202117166303-A
Country	US
Kind code	B2
Filing date	Feb 3, 2021
Priority date	Feb 6, 2020
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

Disclosed are a salt represented by formula (I), and an acid generator and a resist composition which include the same:wherein R1 represents a fluorine atom or a fluorinated alkyl group; R2, R3 and R4 each represent a halogen atom, a fluorinated alkyl group or a hydrocarbon group; m2 and m3 represent an integer of 0 to 4; m4 represents an integer of 0 to 5; Q1 and Q2 each represent a fluorine atom or a perfluoroalkyl group; L1 represents a saturated hydrocarbon group, —CH2- included in the group may be replaced by —O— or —CO—, and a hydrogen atom included in the group may be substituted with a fluorine atom or a hydroxy group; Y1 represents a methyl group which may have a substituent or an alicyclic hydrocarbon group which may have a substituent.

First claim

The invention claimed is:

1. A salt represented by formula (I):

wherein, in formula (I),
R 1 represents a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms,
R 2 , R 3 and R 4 each independently represent a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms or a hydrocarbon group having 1 to 12 carbon atoms, and —CH 2 —included in the hydrocarbon group may be replaced by —O— or —CO—,
m2 represents an integer of 0 to 4, and when m2 is 2 or more, a plurality of R 2 may be the same or different from each other,
m3 represents an integer of 0 to 4, and when m3 is 2 or more, a plurality of R 3 may be the same or different from each other,
m4 represents an integer of 0 to 5, and when m4 is 2 or more, a plurality of R 4 may be the same or different from each other,
Q 1 and Q 2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms,
L 1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, —CH 2 —included in the saturated hydrocarbon group may be replaced by —O— or —CO—, and a hydrogen atom included in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group,
Y 1 represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and —CH 2 — included in the alicyclic hydrocarbon group may be replaced by —O—, —SO 2 — or —CO—.

2. The salt according to claim 1 , wherein R 2 , R 3 and R 4 each independently represent a fluorine atom, an iodine atom or a perfluoroalkyl group having 1 to 4 carbon atoms.

3. The salt according to claim 1 , wherein R 1 represents a fluorinated alkyl group having 1 to 4 carbon atoms.

4. The salt according to claim 1 , wherein L 1 is not a perfluoroalkanediyl group.

5. The salt according to claim 1 , wherein at least one —CH 2 — included in the saturated hydrocarbon group represented by L 1 is replaced by —O— or —CO—.

6. The salt according to claim 1 , wherein Y 1 represents the alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and —CH 2 — included in the alicyclic hydrocarbon group may be replaced by —O—, —SO 2 — or —CO—.

7. An acid generator comprising the salt according to claim 1 .

8. A resist composition comprising the acid generator according to claim 7 and a resin having an acid-labile group.

9. The resist composition according to claim 8 , wherein the resin having an acid-labile group comprises at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2):

wherein, in formula (a1-1) and formula (a1-2),
L a1 and L a2 each independently represent —O— or *—O—(CH 2 ) k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bonding site to —CO—,
R a4 and R a5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom,
R a6 and R a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group obtained by combining these groups,
m1 represents an integer of 0 to 14,
n1 represents an integer of 0 to 10, and
n1′ represents an integer of 0 to 3.

10. The resist composition according to claim 8 , wherein the resin having an acid-labile group comprises a structural unit represented by formula (a2-A):

wherein, in formula (a2-A),
R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom,
R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group,
A a50 represents a single bond or *—X a51 -(A a52 -X a52 ) nb —, and * represents a bonding site to carbon atoms to which —R a50 is bonded,
A a52 represents an alkanediyl group having 1 to 6 carbon atoms,
X a51 and X a52 each independently represent —O—, —CO—O— or —O—CO—,
nb represents 0 or 1, and
mb represents an integer of 0 to 4, and when mb is an integer of 2 or more, a plurality of R a51 may be the same or different from each other.

11. The resist composition according to claim 8 , further comprising a salt generating an acid having an acidity lower than that of an acid generated from the acid generator.

12. A method for producing a resist pattern, which comprises:
(1) a step of applying the resist composition according to claim 8 on a substrate,
(2) a step of drying the applied composition to form a composition layer,
(3) a step of exposing the composition layer,
(4) a step of heating the exposed composition layer, and
(5) a step of developing the heated composition layer.

Assignees

• Sumitomo Chemical Co

Inventors

• Masuyama Tatsuro
• Anryu Yukako
• Ichikawa Koji

Classifications

• C07D307/93

  condensed with a ring other than six-membered · CPC title

• C07C381/12

  Sulfonium compounds · CPC title

• C07D321/10

  condensed with carbocyclic rings or ring systems · CPC title

• C07C2603/74

  Adamantanes · CPC title

• C07D327/04 Primary

  Five-membered rings · CPC title