Positive resist composition and patterning process

Patent metadata

Field	Value
Publication number	US-9335633-B2
Application number	US-201514636668-A
Country	US
Kind code	B2
Filing date	Mar 3, 2015
Priority date	Mar 4, 2014
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A positive resist composition is provided comprising a polymer comprising recurring units having a carboxyl or phenolic hydroxyl group substituted with an acid labile group and recurring units of 4-pyrone ester, and having a Mw of 1,000-500,000. The resist composition has a satisfactory effect of suppressing acid diffusion and a high resolution, and forms a pattern of good profile and minimal edge roughness after exposure.

First claim

The invention claimed is:

1. A positive resist composition comprising a polymer comprising recurring units having a carboxyl and/or phenolic hydroxyl group substituted with an acid labile group and recurring units (a) having a 4-pyrone ester, represented by the general formula (1), and having a weight average molecular weight of 1,000 to 500,000 as a base resin, and an organic solvent

wherein R 1 is hydrogen or methyl, R 2 is methyl or ethyl, and X is a single bond, phenylene group, napthylene group, or a C 1 -C 12 linking group having an ester radical, ether radical or lactone ring.

2. The resist composition of claim 1 wherein the polymer comprises recurring units (a) and acid labile group-substituted recurring units (b1) and/or (b2), as represented by the general formula (2):

wherein R 1 , R 2 and X are as defined above, R 3 and R 5 each are hydrogen or methyl, R 4 and R 8 each are an acid labile group, R 6 is a single bond or a straight or branched C 1 -C 6 alkylene group, R 7 is hydrogen, fluorine, trifluoromethyl, cyano, or straight, branched or cyclic C 1 -C 6 alkyl group, p is 1 or 2, q is an integer of 0 to 4, Y 1 is a single bond, phenylene group, naphthylene group, or a C 1 -C 12 linking group having an ester radical, ether radical or lactone ring, Y 2 is a single bond, —C(═O)—O— or —C(═O)—NH—, a, b1 and b2 are numbers in the range: 0<a<1.0, 0≦b1<1.0, 0≦b2<1.0, 0<b1+b2<1.0, and 0.1≦a+b1+b2≦1.0.

3. The resist composition of claim 2 wherein the polymer further comprises recurring units (c) having an adhesive group selected from the group consisting of hydroxyl, carboxyl, lactone ring, carbonate, thiocarbonate, carbonyl, cyclic acetal, ether, ester, sulfonic acid ester, cyano, amide, and —O—C(═O)-G- wherein G is sulfur or NH and c is a number in the range: 0<c≦0.9 and 0.2≦a+b1+b2+c≦1.0.

4. The resist composition of claim 3 wherein in addition to the recurring units (a) and (c), and units from the group consisting of (b1), (b2) and mixtures thereof, the polymer further comprises recurring units of at least one selected from sulfonium salt units (d1) to (d3) represented by the general formula (3):

wherein R 20 , R 24 , and R 28 each are hydrogen or methyl, R 21 is a single bond, phenylene, —O—R—, or —C(═O)—Y 0 —R—, Y 0 is oxygen or NH, R is a straight, branched or cyclic C 1 -C 6 alkylene group, alkenylene or phenylene group, which may contain a carbonyl, ester, ether or hydroxyl radical, R 22 , R 23 , R 25 , R 26 , R 27 , R 29 , R 30 , and R 31 are each independently (1) a straight, branched or cyclic C 1 -C 12 alkyl group which may contain a carbonyl, ester or ether radical, (2) a C 6 -C 12 aryl group, (3) a C 7 -C 20 aralkyl group, or (4) a thiophenyl group, Z 0 is a single bond, methylene, ethylene, phenylene, fluorophenylene, —O—R 32 —, or —C(═O)—Z 1 —R 32 —, Z 1 is oxygen or NH, R 32 is a straight, branched or cyclic C 1 -C 6 alkylene group, alkenylene or phenylene group, which may contain a carbonyl, ester, ether or hydroxyl radical, M − is a non-nucleophilic counter ion, d1, d2 and d3 are in the range: 0≦d1≦0.5, 0≦d2≦0.5, 0≦d3≦0.5, 0<d1+d2+d3≦0.5, and 0.2≦a+b1+b2+c+d1+d2+d3≦1.0.

5. The resist composition of claim 1 , further comprising an acid generator, the composition being a chemically amplified resist composition.

6. The resist composition of claim 5 , further comprising a basic compound and/or a surfactant as an additive.

7. A pattern forming process comprising the steps of applying the positive resist composition of claim 1 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

8. The process of claim 7 wherein the high-energy radiation is i-line, KrF excimer laser, ArF excimer laser, electron beam or soft X-ray having a wavelength of 3 to 15 nm.

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Hasegawa Koji
• Sagehashi Masayoshi

Classifications

• G03F7/2037

  Exposure with X-ray radiation or corpuscular radiation, through a mask with a pattern opaque to that radiation · CPC title

• G03F7/0045

  with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors · CPC title

• G03F7/2002

  with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image · CPC title

• G03F7/0046

  with perfluoro compounds, e.g. for dry lithography (G03F7/0048 takes precedence) · CPC title

• G03F7/0397 Primary

  the macromolecular compound having an alicyclic moiety in a side chain · CPC title