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# c12) United States Patent 

# Fujiwara et al. 

# (54) SULFONIUM SALT, RESIST COMPOSITION, AND PATTERNING PROCESS 

(71) Applicant: SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP) 

(72) Inventors: Takayuki Fujiwara, Joetsu (JP); Ryo Mitsui, Joetsu (JP); Kazuhiro Katayama, Joetsu (JP) 

(73) Assignee: SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP) 

( *) Notice: Subject to any disclaimer, the term ofthis patent is extended or adjusted under 35 U.S.C. 154(b) by 7 days. 

(21) Appl. No.: 15/903,652 

(22) Filed: Feb. 23, 2018 

## (65) Prior Publication Data 

US 2018/0275516 Al Sep. 27, 2018 

## (30) Foreign Application Priority Data 

Mar. 22, 2017 (JP) ................................... 2017-55526 

(51) Int. Cl. 

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(52) U.S. Cl. CPC .............. G03F 71039 (2013.01); C07C 69/00 (2013.01); C07C 309112 (2013.01); 

( 58) Field of Classification Search CPC ...... G03F 7/039; G03F 7/2059; G03F 7/0397; G03F 7/0045; G03F 7/029; G03F 7/0048; 

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# (IO) Patent No.: US 10,754,248 B2 

# (45) Date of Patent: Aug. 25, 2020 

## (56) References Cited 

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"Refractive index" Website Name: Encyclopaedia Britannica Pub› lisher: Encyclopaedia Britannica, Inc. Date Published: Dec. 28, 2018 URL: https://www.britannica.com/science/refractive-index Access Date: Jul. 26, 2019, one page. (Year: 2018).* 

Primary Examiner - Cynthia Hamilton (74) Attorney, Agent, or Firm - Oliff PLC 

## (57) ABSTRACT 

The present invention provides a sulfonium salt capable of providing a resist composition having few defects in pho› tolithography where a high energy beam is used as a light source, and excellent in lithography performance by con› trolling acid diffusion. 

The present invention was accomplished by a sulfonium salt including an anion and a cation, the cation having a partial structure represented by the following general formula (1), except for a sulfonium salt having a cation represented by the following general formula (1 ’), 

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US010754248B2 

## U.S. PATENT DOCUMENTS 

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## FOREIGN PATENT DOCUMENTS 

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## OTHER PUBLICATIONS 

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