Extraction of the oxide charges at the silicon substrate interface in Silicon-On-Insulator MOSFET's

A new method for extracting the fixed and interface trap densities at the b uried oxide/silicon substrate interface in enhancement-mode and accumulatio n-mode Silicon-On-Insulator MOSFET's is presented. The method is based in t he measurement of the front threshold voltage and body threshold voltage as a function of the applied back gate bias for enhancement-mode and accumula tion-mode devices, respectively, at room and at cryogenic temperatures. Fix ed charge density extraction is made at room temperature and the trapped ch arge density is extracted at cryogenic temperature. The validity of the pro posed technique is demonstrated at liquid nitrogen temperature by two dimen sional simulation and experiments. (C) 1999 Published by Elsevier Science L td. All rights reserved.