Chemically amplified positive resist composition and pattern forming process

Patent metadata

Field	Value
Publication number	US-9720323-B2
Application number	US-201615044827-A
Country	US
Kind code	B2
Filing date	Feb 16, 2016
Priority date	Feb 25, 2015
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A resist composition comprising a resin adapted to be decomposed under the action of acid to increase its solubility in alkaline developer and a sulfonium or iodonium salt of nitrogen-containing carboxylic acid has a high resolution. By lithography, a pattern with minimal LER can be formed.

First claim

What is claimed is:

1. A chemically amplified positive resist composition for high-energy radiation lithography, comprising (A) an onium salt compound having the general formula (1) or (2) and (B) a resin comprising recurring units having the general formula (U-1), adapted to be decomposed under the action of acid to increase its solubility in alkaline developer,

wherein R 01 , R 02 , R 03 and R 04 are each independently hydrogen, -L-CO 2 − , or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or a pair of R 01 and R 02 , R 02 and R 03 , or R 03 and R 04 may bond together to form a ring with the carbon atoms to which they are attached, L is a single bond or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 divalent hydrocarbon group which may be substituted with or separated by a heteroatom, R 05 is hydrogen or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom;
wherein in formula (1), the partial structure represented by the formula:

is a cyclic structure having the intervening nitrogen atom in which a hydrogen atom bonded to a cyclic structure-forming carbon atom may be replaced by a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group or -L-CO 2 − , or in which a cyclic structure-forming carbon atom may be replaced by sulfur, oxygen or nitrogen, with the proviso that one substituent: -L-CO 2 − is essentially included in formula (1), and
R 06 , R 07 , R 08 and R 011 are each independently hydrogen or a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, and R 09 and R 010 are both hydrogen or each independently a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or a pair of R 06 and R 07 may bond together to form a ring with the carbon atoms to which they are attached, a pair of R 08 and R 011 may bond together to form a ring with the carbon atoms to which they are attached and any intervening carbon atoms, or a pair of R 09 and R 010 may bond together to form a ring with the nitrogen atom, j is 0 or 1, k is a number in the range: 0≦k≦1 when j=0, or 0≦k≦3 when j=1, and Z + is a sulfonium cation of the general formula (a) or an iodonium cation of the general formula (b):

wherein R 100 , R 200 , and R 300 are each independently a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom, or any two or more of R 100 , R 200 , and R 300 may bond together to form a ring with the sulfur atom, R 400 and R 500 are each independently a straight C 1 -C 20 , branched or cyclic C 3 -C 20 monovalent hydrocarbon group which may be substituted with or separated by a heteroatom; and

wherein general formula (U-1) is the following structure:

wherein q is 0 or 1, r is an integer of 0 to 2, R 1 is hydrogen, fluorine, methyl or trifluoromethyl, R 2 is each independently hydrogen or C 1 -C 6 alkyl, B 1 is a single bond or C 1 -C 10 alkylene group which may contain an ether bond, a is an integer satisfying a≦5+2r−b, and b is an integer of 1 to 3.

2. The resist composition of claim 1 wherein the anion moiety of the onium salt compound having formula (1) is selected from the following formulae (1)-1 to (1)-65, and the anion moiety of the onium salt compound having formula (2) is selected from the following formulae (2)-1 to (2)-43

3. The resist composition of claim 1 wherein said resin (B) further comprises recurring units having the general formula (U-2):

wherein s is 0 or 1, t is an integer of 0 to 2, R 1 , R 2 and B 1 are as defined above, c is an integer satisfying c≦5+2t−e, d is 0 or 1, e is an integer of 1 to 3, X is an acid labile group when e is 1, and X is hydrogen or an acid labile group when e is 2 or 3, at least one X being an acid labile group.

4. The resist composition of claim 3 wherein the acid labile group is a tertiary alkyl group in which alkyl substituents on tertiary carbon are straight, branched or cyclic C 1 -C 15 alkyl groups which may contain an oxygen-containing functional group, and alkyl substituents on tertiary carbon may bond together to form a ring, or an acetal group of the general formula (U-2-1),

wherein R 24 is hydrogen or a straight, branched or cyclic C 1 -C 10 alkyl group, and W is a straight, branched or cyclic C 1 -C 30 alkyl group.

5. The resist composition of new claim 4 wherein W is a C 7 -C 30 polycyclic alkyl group.

6. The resist composition of claim 1 wherein said resin (B) further comprises recurring units of at least one type selected from units having the general formulae (U-3) and (U-4):

wherein f is an integer of 0 to 6, R 3 is each independently hydrogen, an optionally halo-substituted C 1 -C 6 alkyl or primary or secondary alkoxy group, or an optionally halo-substituted C 1 -C 7 alkylcarbonyloxy group, g is an integer of 0 to 4, and R 4 is each independently hydrogen, an optionally halo-substituted C 1 -C 6 alkyl or primary or secondary alkoxy group, or an optionally halo-substituted C 1 -C 7 alkylcarbonyloxy group.

7. The resist composition of claim 1 wherein said resin (B) further comprises recurring units of at least one type selected from units having the general formulae (a1), (a2) and (a3):

wherein R 12 is ea

Assignees

• Shinetsu Chemical Co

Inventors

• Kotake Masaaki
• Fujiwara Takayuki
• Masunaga Keiichi
• Domon Daisuke
• Watanabe Satoshi

Classifications

• H10P76/2041

  Photolithographic processes · CPC title

• H10P76/20

  of masks comprising organic materials · CPC title

• G03F7/0045

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

• C08F220/26

  Esters containing oxygen in addition to the carboxy oxygen · CPC title

• G03F7/2037

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