(19)

(11)

EP 0 954 881 A1

(12)

(43) Date of publication: 10.11.1999 Bulletin 1999/45 (21) Application number: 97950833.0 (22) Date of filing: 26.11.1997

(51) International Patent Classification (IPC):  G01D 21/ 00( . ) H01L 31/ 10( . ) H01L 31/ 08( . ) H03K 17/ 78( . ) (86) International application number: PCT/US1997/022229 (87) International publication number: WO 1999/027589 (03.06.1999 Gazette 1999/22)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (71) Applicant: Chow, Alan Y. Wheaton, Illinois 60187 (US)	(72) Inventors: CHOW, Alan, Y. Wheaton, IL 60187 (US) CHOW, Vincent, Y. Hanover Park, IL 60103 (US) (74) Representative: Pellmann, Hans-Bernd, Dipl.-Ing.  Patentanwaltsbüro Tiedtke-Bühling-Kinne & Partner Bavariaring 4 80336 München 80336 München (DE)