(19)

(11)

EP 0 715 770 A1

(12)

(43) Date of publication: 12.06.1996 Bulletin 1996/24 (21) Application number: 94922567.0 (22) Date of filing: 15.07.1994

(51) International Patent Classification (IPC):  H01L 21/ 761( . ) H01L 21/ 76( . ) H01L 21/ 265( . ) (86) International application number: PCT/US1994/007958 (87) International publication number: WO 1995/006956 (09.03.1995 Gazette 1995/11)

(84) Designated Contracting States: DE FR GB (30) Priority: 03.09.1993 US 19930117574 (71) Applicant: NATIONAL SEMICONDUCTOR CORPORATION Santa Clara, California 95052 (US)	(72) Inventors: HANSON, David, A. Palo Alto, CA 94303 (US) ARONOWITZ, Sheldon San Jose, CA 95127 (US) DEMIRLIOGLU, Esin, K. Cupertino, CA 95014 (US) (74) Representative: Bowles, Sharon Margaret, et al  BOWLES HORTON Felden House Dower Mews High Street Berkhamsted Hertfordshire HP4 2BL Berkhamsted Hertfordshire HP4 2BL (GB)