(19)

(11)

EP 0 966 760 A1

(12)

(43) Date of publication: 29.12.1999 Bulletin 1999/52 (21) Application number: 97904108.0 (22) Date of filing: 07.02.1997

(51) International Patent Classification (IPC):  H01L 29/ 267( . ) H01L 29/ 20( . ) H01L 29/ 737( . ) (86) International application number: PCT/US1997/001515 (87) International publication number: WO 1998/035388 (13.08.1998 Gazette 1998/32)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (71) Applicant: Northrop Grumman Corporation Los Angeles, California 90067-2199 (US)	(72) Inventors: AGARWAL, Anant, K. Monroeville, PA 15146 (US) MESSHAM, Rowan, L. Murrysville, PA 15668 (US) DRIVER, Michael, C. McKeesport, PA 15135 (US) (74) Representative: O'Reilly, Peter Andrew, et al  Albihns GmbH, Grasserstrasse 10 80339 München 80339 München (DE)