US 12,240,804 B2
Onium salt, chemically amplified resist composition and patterning process
Takayuki Fujiwara, Joetsu (JP); Satoshi Watanabe, Joetsu (JP); and Kousuke Ohyama, Joetsu (JP)
Assigned to SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed on Oct. 6, 2021, as Appl. No. 17/495,166.
Claims priority of application No. 2020-177024 (JP), filed on Oct. 22, 2020.
Prior Publication US 2022/0127225 A1, Apr. 28, 2022
Int. Cl. C07C 381/12 (2006.01); G03F 7/004 (2006.01); G03F 7/038 (2006.01); G03F 7/20 (2006.01); G03F 7/32 (2006.01); G03F 7/40 (2006.01)
CPC C07C 381/12 (2013.01) [G03F 7/0045 (2013.01); G03F 7/0382 (2013.01); G03F 7/2006 (2013.01); G03F 7/327 (2013.01); G03F 7/40 (2013.01)] 15 Claims
OG exemplary drawing
 
6. A chemically amplified resist composition comprising:
(A′) a base polymer comprising repeat units having the formula (a) or repeat units having the formula (b) and repeat units adapted to generate an acid upon light exposure,
(C-1) the acid diffusion inhibitor, comprising an onium salt having the formula (1), and
(D) an organic solvent,

OG Complex Work Unit Chemistry
wherein X is sulfur,
n is 1 when X is sulfur,
R1 is a C1-C5 hydrocarbyl group which may contain fluorine or oxygen,
R2 and R3 are each independently a C1-C30 hydrocarbyl group which may contain a heteroatom, R2 and R3 may bond together to form a ring with X to which they are attached,
Ar is a C6-C14 arylene group which may be substituted with a substituent selected from a halogen atom, hydroxy group, C1-C10 hydrocarbyl group which may contain a heteroatom, C1-C10 hydrocarbyloxy group which may contain a heteroatom, C2-C10 hydrocarbylcarbonyl group which may contain a heteroatom, and C2-C10 hydrocarbylcarbonyloxy group which may contain a heteroatom, R2 and Ar may bond together to form a ring with X to which they are attached, and
Z− is a carboxylate, sulfonamide, sulfonimide or methide anion,

OG Complex Work Unit Chemistry
wherein RA is each independently hydrogen or methyl,
XA is a single bond, phenylene group, naphthylene group or (backbone)-C(═O)—O—XA1—, XA1 is a C1-C15 hydrocarbylene group which may contain a hydroxy moiety, ether bond, ester bond, or lactone ring,
XB is a single bond or ester bond,
AL1 and AL2 are each independently an acid labile group.