(19)

(11)

EP 1 502 308 A1

(12)

(43) Date of publication: 02.02.2005 Bulletin 2005/05 (21) Application number: 02734064.5 (22) Date of filing: 26.04.2002

(51) International Patent Classification (IPC)7: H01L 31/0328 (86) International application number: PCT/US2002/013315 (87) International publication number: WO 2003/092079 (06.11.2003 Gazette 2003/45)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (71) Applicant: International Business Machines Corporation Armonk, N.Y. 10504 (US)	(72) Inventors: Johnson, Robb Allen Thousand Oaks, CA 91360 (US) Lanzerotti, Louis D. Burlington, VT 05406 (US) (74) Representative: Waldner, Philip  IBM United Kingdom Limited,MP 110,Hursley Park Winchester SO21 2JN Winchester SO21 2JN (GB)