(19)

(11)

EP 0 243 392 A1

(12)

(43) Date of publication: 04.11.1987 Bulletin 1987/45 (21) Application number: 86905875.0 (22) Date of filing: 23.09.1986

(51) International Patent Classification (IPC):  H01L 21/ 762( . ) (86) International application number: PCT/GB1986/000572 (87) International publication number: WO 1987/002180 (09.04.1987 Gazette 1987/08)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 27.09.1985 GB 19850023848 (71) Applicant: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and London SW1A 2HB (GB)	(72) Inventors: BENJAMIN, John, David Malvern Worcester WR14 3LG (GB) KEEN, John, Michael Worcester WR8 OPN (GB) (74) Representative: Russell, James, Dr., et al  Defence Research Agency Intellectual Property Department DRA Farnborough Farnborough, Hants. GU14 6TD Farnborough, Hants. GU14 6TD (GB)