(19)

(11)

EP 0 247 119 A1

(12)

(43) Date of publication: 02.12.1987 Bulletin 1987/49 (21) Application number: 86906883.0 (22) Date of filing: 20.11.1986

(51) International Patent Classification (IPC):  H01L 21/ 285( . ) H01L 29/ 45( . ) (86) International application number: PCT/GB1986/000708 (87) International publication number: WO 1987/003425 (04.06.1987 Gazette 1987/12)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 29.11.1985 GB 19850029382 (71) Applicant: PLESSEY OVERSEAS LIMITED Ilford Essex IG1 4AQ (GB)	(72) Inventor: FOSTER, David, John 11 Draycott Close Northampton, NN3 3BD (GB)