c19)  United States  c12)  Patent Application Publication  Mizutani  c10)  Pub. No.: US 2007/0072121 Al  (43)  Pub. Date:  Mar. 29, 2007  (54)  POSITIVE RESIST COMPOSITION AND  PATTERN FORMING METHOD USING THE  SAME  (75)  Inventor:  Kazuyoshi Mizutani,  Shizuoka (JP)  (73)  Assignee:  FUJI PHOTO FILM CO., LTD.  (21)  Appl. No.:  11/529,442  (22)  Filed:  Sep. 29, 2006  (51)  Int. Cl.  G03C 1100  (2006.01)  (52)  U.S. Cl.  ..........................................................  430/270.1  action of an acid, the resin including a repeating unit  represented by formula  (Ia) and a repeating unit represented  by formula (Al); and (B) a compound capable of generating  an acid upon irradiation with one of actinic ray and radia› tion:  wherein  in the formula (Ia), AR represents an aromatic group, and X$_{1 }$ represents a group having a carbon number of 5 or more and  being capable of decomposing under the action of an acid,  and in the formula (Al), m represents an integer of one of  1 and 2.  A positive resist composition including: (A-1) a resin of  which a solubility in an alkali developer increases under the  Sep. 29, 2005  (JP) ................................... P.2005-285022  Correspondence Address:  SUGHRUE-265550  2100 PENNSYLVANIA AVE. NW  WASHINGTON, DC 20037-3213 (US)  US 20070072121Al  (30)  Foreign Application Priority Data  Publication Classification  (57)  ABSTRACT  (la)  AR  I  ---fCH-CH-t- 1  C=O  I  OX1  (Al) 