(19)

(11)

EP 0 621 980 A1

(12)

(43) Date of publication: 02.11.1994 Bulletin 1994/44 (21) Application number: 94900220.0 (22) Date of filing: 16.11.1993

(51) International Patent Classification (IPC):  H01L 21/ 285( . ) H01L 21/ 3205( . ) H01L 21/ 00( . ) H01L 21/ 768( . ) (86) International application number: PCT/GB1993/002359 (87) International publication number: WO 1994/013008 (09.06.1994 Gazette 1994/13)

(84) Designated Contracting States: AT BE CH DE ES FR GB IE IT LI NL SE (30) Priority: 19.11.1992 GB 19920024260 (71) Applicant: ELECTROTECH LIMITED Thornbury, Bristol BS12 1NP (GB)	(72) Inventor: DOBSON, Christopher David Olveston, Bristol BS12 3AA (GB) (74) Representative: Dunlop, Brian Kenneth Charles, et al  c/o Wynne-Jones, Lainé & James 22 Rodney Road Cheltenham Gloucestershire GL50 1JJ Cheltenham Gloucestershire GL50 1JJ (GB)