(19)

(11)

EP 0 269 692 A1

(12)

(43) Date of publication: 08.06.1988 Bulletin 1988/23 (21) Application number: 87903761.0 (22) Date of filing: 20.04.1987

(51) International Patent Classification (IPC):  G03F 1/ 00( . ) H01L 21/ 027( . ) G03F 1/ 14( . ) (86) International application number: PCT/US1987/000878 (87) International publication number: WO 1987/007400 (03.12.1987 Gazette 1987/27)

(84) Designated Contracting States: DE FR GB (30) Priority: 27.05.1986 US 19860867659 (71) Applicant: Hughes Aircraft Company Los Angeles California 90045-0066 (US)	(72) Inventors: ATKINSON, Gary, M. Los Angeles, CA 90025 (US) BARTELT, John, L. Thousand Oaks, CA 91360 (US) (74) Representative: KUHNEN, WACKER & PARTNER  Patent- und Rechtsanwaltsbüro, Alois-Steineckerstrasse 22 D-85354 Freising D-85354 Freising (DE)