(10)  Patent No.:  US 7,232,640 Bl  (45)  Date of Patent:  Jun.19,2007  c12)  United States Patent  Mizutani et al.  (54)  POSITIVE RESIST COMPOSITION  (75)  Inventors:  Kazuyoshi Mizutani,  Shizuoka (JP);  Shoichiro Yasunami,  Shizuoka (JP)  (73)  Assignee:  Fujifilm Corporation,  Tokyo (JP)  ( *)  Notice:  Subject to any disclaimer, the term of this  patent is extended or adjusted under 35  U.S.C. 154(b) by  O  days.  (21)  Appl. No.:  10/812,092  (22)  Filed:  Mar. 30, 2004  (30)  Foreign Application Priority Data  Mar. 31, 2003  (JP)  ......................... P. 2003-096390  (51)  Int. Cl.  G03F  71039  (2006.01)  G03F  7126  (2006.01)  (52)  U.S. Cl.  ....................................  430/270.1;  430/326  (58)  Field of Classification Search  .............. 430/270.1  See application file for complete search history.  (56)  References Cited  U.S. PATENT DOCUMENTS  5,558,976 A *  5,643,669 A *  5,837,420 A *  6,051,370 A *  2001/0008739 Al *  2003/0065101 Al *  2003/0114589 Al*  9/1996 Urano et al. ............. 430/270.1  7/1997 Tsuei .......................... 428/354  11/1998 Aoai et al. ............... 430/270.1  4/2000 Kim ........................ 430/270.1  7/2001 Nishyama et al. ....... 430/270.1  4/2003 Blakeney et al. ........... 525/288  6/2003 Suetsugu et al. ........... 525/132  2003/0224287 Al* 12/2003 Fujimori .................. 430/270.1  FOREIGN PATENT DOCUMENTS  JP  JP  JP  JP  2-19847 A  4-219757 A  2002-49156 A  2002-323768 A  1/1990  8/1992  2/2002  11/2002  OTHER PUBLICATIONS  Toru et al, Publication No. 2002-049156, English abstract of  JP2002-049156 published Feb. 15, 2002 with attached machine  translated Claims and Example of Document from Patent Abstracts  of Japan, copyright 2003, Japan Patent Office, 9 pages.*  Tsiartas et  al , "The Mechanism of Phenolic Polymer Dissolution:  A New Perspective", Macromolecules, 1977, vol. 30, pp. 4656- 4664.*  Thomson translation of JP 2002-49156 published Feb. 15, 2002, 96  pages.*  Flanigan et al, "Surface roughness development during photoresist  dissolution," J. Vac. Sci. Technol. B 17 (4), Jul./Aug. 1999, Ameri› can Vacuum Society, pp. 1371-1379.*  * cited by examiner  Primary Examiner--Cynthia  Hamilton  (74)  Attorney, Agent, or Firm-Sughrue  Mion, PLLC  (57)  ABSTRACT  13 Claims, No Drawings  A positive resist composition comprising a polymer capable  of increasing its solubility in an alkali developer under  action of an acid, wherein the resin comprises repeating  units containing at least two special types of acetal structures  separately, a compound capable of generating an acid upon  irradiation with an actinic ray or radiation, and a solvent.  US007232640B 1 