Measurement of carrier generation lifetime in SOI devices

Abstract

This paper presents a new, simple method of measuring the generation lifetime in SOI (silicon-on-insulator) MOSFETS, Lifetime is extracted from the transient characteristics of MOSFET subthreshold current. Using this technique, generation lifetime was mapped across finished SIMOX (separation by implantated oxygen) wafers, BESOI (bonded and etchedback SOI) wafers, and UNIBOND wafers. BESOI material evaluated in this study had about seven times longer effective generation lifetime than SIMOX material and the three types of the SOI wafers are shown to have a lifetime variation of +/-20% across four inch wafers, The generation lifetime was also found to depend on the device fabrication process. (C) 1998 Elsevier Science Ltd. All rights reserved.