1111111111111111 IIIIII IIIII 1111111111 11111 111111111111111 111111111111111 1111111111 11111111  US 20200192221Al  c19)  United States  c12)  Patent Application Publication  Hatakeyama  c10)  Pub. No.: US 2020/0192221 Al  (43)  Pub. Date:  Jun. 18, 2020  (54)  POSITIVE RESIST COMPOSITION AND  PATTERN FORMING PROCESS  (57)  ABSTRACT  (71)  Applicant:  Shin-Etsu Chemical Co., Ltd.,  Tokyo  (JP)  (72)  Inventor:  Jun Hatakeyama,  Joetsu-shi (JP)  (73)  Assignee:  Shin-Etsu Chemical Co., Ltd.,  Tokyo  (JP)  (21)  Appl. No.:  16/708,851  (22)  Filed:  Dec. 10, 2019  A positive resist composition comprising a base polymer  comprising recurring units having a nitrogen-containing  tertiary ester structure exhibits a high sensitivity, high reso› lution, low edge roughness (LER, LWR) and small size  variation, and forms a pattern of good profile after exposure  and development.  Publication Classification  (51)  Int. Cl.  G03F  71039  C08F  220118  C08F  212114  (2006.01)  (2006.01)  (2006.01)  (30)  Foreign Application Priority Data  Dec. 14, 2018  (JP) ................................. 2018-234513  (52)  U.S. Cl.  CPC ..............  G03F  71039  (2013.01);  G03F 7/162  (2013.01);  C08F  212114  (2013.01);  C08F  220118  (2013.01) 