Positive resist composition and patterning process

Patent metadata

Field	Value
Publication number	US-9335632-B2
Application number	US-201414330272-A
Country	US
Kind code	B2
Filing date	Jul 14, 2014
Priority date	Sep 4, 2013
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 and/or phenolic hydroxyl group substituted with an acid labile group and recurring units of tert-butyl or tert-amyl-substituted hydroxyphenyl methacrylate and having a weight average molecular weight 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 represented by the general formula (1), and having a weight average molecular weight of 1,000 to 500,000 as a base resin,

wherein R 1 is hydrogen or methyl, R 2 is hydrogen or methyl, m and n each are 1 or 2.

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

wherein R 1 , R 2 , m and n 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, a C 1 -C 12 linking group having an ester radical, ether radical or lactone ring, phenylene group or naphthylene group, 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<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 class 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, provided that recurring units (a), (b1) and (b2) are excluded from recurring units (c).

4. The resist composition of claim 3 wherein in addition to the recurring units (a), (b1) and/or (b2), and (c) wherein 0.2≦a+b1+b2+c<1.0, the polymer further comprises recurring units of at least one type selected from sulfonium salt units (dl) 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 a straight, branched or cyclic C 1 -C 12 alkyl group which may contain a carbonyl, ester or ether radical, or a C 6 -C 12 aryl, C 7 -C 20 aralkyl, or 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 organic solvent and 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 KrF excimer laser, electron beam or soft X-ray having a wavelength of 3 to 15 nm.

9. A pattern forming process comprising the steps of applying the positive resist composition of claim 2 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

10. A pattern forming process comprising the steps of applying the positive resist composition of claim 3 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

11. A pattern forming process comprising the steps of applying the positive resist composition of claim 4 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

12. A pattern forming process comprising the steps of applying the positive resist composition of claim 5 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

13. A pattern forming process comprising the steps of applying the positive resist composition of claim 6 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

14. The resist composition of claim 1 wherein the polymer comprises recurring units (a) and acid labile group substituted recurring units (b1) copolymerized together, as represented by the general formula (1′):

wherein R 1 , R 2 , m and n are as defined above, R 3 is hydrogen or methyl, R 4 is an acid labile group, Y 1 is a single bond, a C 1 -C 12 linking group having an ester radical, ether radical or lactone ring, phenylene group or naphthylene group, a and b1 are numbers in the range: 0<a<1.0, 0<b1<1.0, and 0.1≦a+b1≦1.0.

15. The resist composition of claim 1 wherein R 1 is methyl.

16. The resist composition of claim 2 wherein R 1 is methyl.

17. The resist composition of claim 14 wherein R 1 is methyl.

18. The resist composition of claim 2 wherein Y 2 is a single bond or —C(═O)—O—.

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Hasegawa Koji

Classifications

• G03F7/085

  Photosensitive compositions characterised by adhesion-promoting non-macromolecular additives (G03F7/075 takes precedence) · CPC title

• G03F7/0395

  the macromolecular compound having a backbone with alicyclic moieties · CPC title

• G03F7/0397

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

• G03F7/039 Primary

  Macromolecular compounds which are photodegradable, e.g. positive electron resists (G03F7/075 takes precedence; macromolecular quinonediazides G03F7/023) · CPC title

• G03F7/004

  Photosensitive materials (G03F7/12, G03F7/14 take precedence) · CPC title