(1-1)  (1-2)  0  (1-3)  0  (1-4)  0  (1-5)  wherein R $^{1 }$to R$^{5 }$represent a linear, branched, or cyclic alkyl  group having 1 to 4 carbon atoms, an alkenyl group having  2 to 4 carbon atoms, or an alkynyl group having 2 to 4  carbon atoms; R $^{6 }$represents a hydroxyl group or an alkoxy  group or acyloxy group having 1 to 6 carbon atoms; and "m"  represents 1 or 2. There can be provided a resist composition  (Continued)  The present invention provides a resist composition con› taining a base resin composed of a polymer compound  (Continued)  "Sigma Steroids",ThermoFischer Scientific, (2007) 43 pages.*  (Continued)  Primary Examiner  - Martin J Angebranndt  (Continued)  (Continued)  (Continued)  (IO)  Patent No.:  US 10,005,868 B2  US010005868B2  (45)  Date of Patent:  Jun.26,2018  c12)  United States Patent  Hatakeyama et al.  (54)  RESIST COMPOSITION AND PATTERNING  PROCESS USING THE SAME  having a repeating unit in which a hydrogen atom of a  carboxyl group is substituted with one or more acid-labile  groups selected from groups shown by the following general  formulae (1-1) to (1-5),  (71)  Applicant:  SHIN-ETSU CHEMICAL CO., LTD.,  Tokyo (JP)  (72)  Inventors:  Jun Hatakeyama,  Jyoetsu (JP);  Koji  Hasegawa,  Jyoetsu (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  O  days. days.  (21)  Appl. No.:  15/195,387  Jun. 28, 2016  (22)  Filed:  (65)  Prior Publication Data  (30)  Foreign Application Priority Data  (51)  Int. Cl.  G03F  71039  G03F  7120  (2006.01)  (2006.01)  (52)  U.S. Cl.  CPC ........  C0SF  222114  (2013.01);  C0SF 2161165  (2013.01);  C0SF 220168  (2013.01);  US 2017/0029547 Al  Feb. 2, 2017  Jul. 29, 2015  (JP) ................................. 2015-149895  ( 58)  Field of Classification Search  None  See application file for complete search history.  (56)  References Cited  U.S. PATENT DOCUMENTS  2,864,831 A * 12/1958 Eppstein ................. Cl2P 33/00  5,879,851 A  3/1999 Takahashi et al.  435/60  CA  FR  2049772 Al  2/1992  2270849  *  12/1975  FOREIGN PATENT DOCUMENTS  OTHER PUBLICATIONS  (57)  ABSTRACT  (74)  Attorney, Agent, or Firm  - Oliff PLC 