(19)

(11)

EP 0 852 768 A1

(12)

(43) Date of publication: 15.07.1998 Bulletin 1998/29 (21) Application number: 97932184.0 (22) Date of filing: 13.06.1997

(51) International Patent Classification (IPC):  H01L 21/ 82( . ) G06F 17/ 50( . ) (86) International application number: PCT/US1997/010305 (87) International publication number: WO 1997/048061 (18.12.1997 Gazette 1998/02)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 14.06.1996 US 19960019767P (71) Applicant: Cascade Design Automation Corporation Bellevue, Washington 98006 (US)	(72) Inventors: FISHER, Louis, C. Bainbridge Island, WA 98110 (US) JENSEN, John, S. Tacoma, WA 98407 (US) ROSSMAN, Thomas, F. Issaquah, WA 98029 (US) (74) Representative: Baillie, Iain Cameron  Ladas & Parry, Altheimer Eck 2 80331 München 80331 München (DE)