(19)

(11)

EP 1 425 595 A1

(12)

(43) Date of publication: 09.06.2004 Bulletin 2004/24 (21) Application number: 01975166.8 (22) Date of filing: 14.09.2001

(51) International Patent Classification (IPC)7: G01R 33/035, H01L 39/00 (86) International application number: PCT/US2001/026024 (87) International publication number: WO 2003/025603 (27.03.2003 Gazette 2003/13)

(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: University of Maryland College Park Riverdale, MD 20737 (US)	(72) Inventors: WELLSTOOD, Fred Lanham, MD 20706 (US) CHATRAPHORN, SojiphongDepartment of Physics Phyathai Road, Bangkok 10330 (TH) FLEET, Erin Alexandria, VA 22314 (US) (74) Representative: Harris, Ian Richard  D. Young & Co.,21 New Fetter Lane London EC4A 1DA London EC4A 1DA (GB)