Doping measurements in thin silicon-on-insulator films

This paper focuses on doping type and doping level characterization of sili con-on-insulator wafers prior to device fabrication. The ability of the poi nt-contact pseudo-metar-oxide-semiconductor transistor to analyze backgroun d doping is investigated thoroughly both theoretically and through a compar ison with secondary ion mass spectroscopy on intentionally doped wafers. A new method using mercury contacts is proposed to determine the semiconducto r type for extremely low doping levels. No sample preparation is needed and unambiguous results are obtained. The physical basis of the measurement is investigated and the method is demonstrated on bulk and silicon-on-insulat or wafers. (C) 1999 The Electrochemical Society. All rights reserved.