Pattern forming process and shrink agent

Patent metadata

Field	Value
Publication number	US-9927708-B2
Application number	US-201614991050-A
Country	US
Kind code	B2
Filing date	Jan 8, 2016
Priority date	Jan 9, 2015
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A negative pattern is formed by applying a resist composition onto a substrate, exposing the resist film, and developing the exposed resist film in an organic solvent developer. The process further involves coating the negative pattern with a shrink agent solution of a first polymer comprising recurring units capable of forming carboxyl, hydroxyl or lactone ring and a second polymer comprising recurring units capable of forming amino and fluorinated recurring units in an ester and/or ketone solvent, baking the coating, and removing the excessive shrink agent for thereby shrinking the size of spaces in the pattern.

First claim

The invention claimed is:

1. A pattern forming process comprising the steps of:
applying a resist composition comprising a polymer comprising recurring units having an acid labile group-substituted carboxyl group, an acid generator and an organic solvent onto a substrate,
prebaking to form a resist film,
exposing the resist film to high-energy radiation,
baking the film,
developing the exposed resist film in an organic solvent-based developer to form a negative pattern,
applying a shrink agent onto the negative pattern, the shrink agent being a solution of a first polymer comprising recurring units of at least one type selected from units (a1) to (a4) in general formula (1) and a second polymer comprising recurring units having an amino group protected with an acid labile group, represented by the general formula (2) in an ester solvent of 7 to 16 carbon atoms and/or ketone solvent of 8 to 16 carbon atoms,
baking, and
removing the excessive shrink agent with the organic solvent-based developer for thereby shrinking the size of spaces in the pattern,

wherein R 1 , R 3 , R 6 , R 12 , R 20 and R 23 each are hydrogen or methyl,
R 2 , R 5 , R 14 and R 22 each are an acid labile group,
X 1 is a single bond, a phenylene or naphthylene group, or —C(═O)—O—R 16 —, R 16 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain ether, ester, lactone ring or hydroxyl, or a phenylene or naphthylene group,
X 2 is a single bond, a phenylene or naphthylene group which may contain nitro, cyano or halogen, or —C(═O)—O—R 17 —, —C(═O)—NH—R 17 —, —O—R 17 —, or —S—R 17 —, R 17 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain ether, ester, lactone ring or hydroxyl, or a phenylene or naphthylene group which may contain a straight, branched or cyclic C 1 -C 6 alkyl, alkoxy, acyl, acyloxy, C 2 -C 6 alkenyl, alkoxycarbonyl, C 6 -C 10 aryl, nitro, cyano, or halogen,
R 4 is a single bond, a di to penta-valent, straight, branched or cyclic C 1 -C 16 aliphatic hydrocarbon group, or phenylene group, which may contain ether or ester,
m is 1 to 4,
R 7 and R 8 are each independently hydrogen, fluorine, or a straight, branched or cyclic C 1 -C 8 monovalent hydrocarbon group,
R 9 , R 13 and R 15 each are hydrogen, or a straight, branched or cyclic C 1 -C 20 monovalent hydrocarbon group in which any constituent —CH 2 — moiety may be replaced by —O— or —C(═O)—, or whose hydrogen may be replaced by halogen,
R 10 and R 11 are each independently hydrogen, or a straight, branched or cyclic C 1 -C 8 monovalent hydrocarbon group, or R 10 and R 11 may bond together to form a C 3 -C 17 non-aromatic ring with the carbon atom to which they are attached,
X 3 and X 4 each are a straight, branched or cyclic C 1 -C 20 divalent hydrocarbon group in which any constituent —CH 2 — moiety may be replaced by —O— or —C(═O)—,
k 1 and k 2 each are 0 or 1,
Y 1 is a single bond, phenylene group or —C(═O)—O—R 25 —, R 25 is a single bond, a straight, branched or cyclic C 1 -C 10 alkylene group which may contain ether, ester, —N═ or —S—, or a phenylene or naphthylene group,
R 21 is hydrogen, or a straight or branched C 1 -C 4 alkyl group,
Y 2 is a phenylene, —C(═O)—O—R 26 — or ether group, R 26 is a single bond or a straight, branched or cyclic C 1 -C 10 alkylene group which may contain ether, ester or —S—,
R 24 is fluorine or a straight, branched or cyclic C 1 -C 14 alkyl group containing at least one fluorine atom which may contain hydroxy, ether or ester,
n is 1 or 2, p is an integer of 1 to 6,
0≤a1≤1.0, 0≤a2≤1.0, 0≤a3≤1.0, 0≤a4≤1.0, 0<a1+a2+a3+a4≤1.0, 0<b1<1.0, 0<b2<1.0, and 0<b1+b2≤1.0.

2. The pattern forming process of claim 1 wherein the first polymer comprising recurring units (a1) to (a4) further comprises recurring units (c) having a hydroxyl, carboxyl, lactone ring, lactam ring, sultone ring, sulfone, sulfonic acid ester, sulfonamide, carboxylic acid amide, nitro, cyano, thienyl, furyl, pyrrole, acid anhydride, imide, —NH—(C═O)—O—, —S—(C═O)—O—, or —ON(═O 2 )—.

3. The pattern forming process of claim 1 wherein the shrink agent further comprises a salt compound having the general formula (4):
R 27 —CO 2 − M +   (4)

wherein R 27 is a straight, branched or cyclic C 1 -C 20 alkyl group, C 2 -C 20 alkenyl group or C 6 -C 20 aryl group which may contain fluorine, ether, ester, lactone ring, lactam ring, carbonyl or hydroxyl, and M is sulfonium, iodonium or ammonium.

4. The pattern forming process of claim 1 wherein the solvent for the shrink agent is at least one solvent selected from the group consisting of:
ester solvents of 7 to 16 carbon atoms including pentyl acetate, isopentyl acetate, 2-methylbutyl acetate, hexyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, hexyl formate, ethyl valerate, propyl valerate, isopropyl valerate, butyl valerate, isobutyl valerate, tert-butyl valerate, pentyl valerate, isopentyl valerate, ethyl isovalerate, propyl isovalerate, isopropyl isovalerate, butyl isovalerate, isobutyl isovalerate, tert-butyl isovalerate, isopentyl isovalerate, ethyl 2-methylvalerate, butyl 2-methylvalerate, ethyl pivalate, propyl pivalate, isopropyl pivalate, butyl pivalate, tert-butyl pivalate, ethyl pentenoate, propyl pentenoate, isopropyl pentenoate, butyl pentenoate, tert-butyl pentenoate, propyl crotonate, isopropyl crotonate, butyl crotonate, tert-butyl crotonate, butyl propionate, isobutyl propionate, tert-butyl propionate, benzyl propionate, ethyl hexanoate, allyl hexanoate, propyl butyrate, butyl butyrate, isobutyl butyrate, 3-methylbutyl butyrate, tert-butyl butyrate, ethyl 2-methylbutyrate, isopropyl 2-methylbutyrate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, ethyl phenylacetate, and 2-phenylethyl acetate,
ketone solvents of 8 to 16 carbon atoms including 2-octanone, 3-octanone, 4-octanone, 2-nonanone, 3-nonanone, 4-nonanone, 5-nonanone, diisobutyl ketone, ethylcyclohexanone, ethylacetophenone, ethyl n-butyl ketone, di-n-butyl ketone, and diisobutyl ketone.

5. The pattern forming process of claim 1 wherein the polymer in the resist composition further comprises recurring units (a5) having the general formula (3):

wherein R 30 is hydrogen or methyl, R 31 is an acid labile group, Z is a single bond or —C(═O)—O—R 32 —, R 32 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain ether or ester, or naphthylene group, and 0<a5<1.0.

6. The pattern forming process of claim 1 wherein the developer for forming a negative pattern comprises at least one solvent selected from the group consisting of 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate, butenyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethy

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Katayama Kazuhiro
• Sagehashi Masayoshi

Classifications

• C08F212/24 Primary

  Phenols or alcohols · CPC title

• C08F212/20

  Fluorine · CPC title

• C08F212/22

  Oxygen · CPC title

• C08F12/20

  Fluorine · CPC title

• G03F7/325

  Non-aqueous compositions · CPC title