IMPACT OF SCALING SILICON FILM THICKNESS AND CHANNEL WIDTH ON SOI MOSFET WITH REOXIDIZED MESA ISOLATION

The characteristics of reoxidized MESA isolation for silicon-on-insula tor (SOI) MOSFET hale been studied in terms of the dependence of devic e performance on silicon film thickness and channel width scaling. For devices with silicon film thickness (T-si) smaller than a critical th ickness, humps appear in subthreshold IV and negative threshold voltag e shift is observed in narrow width devices. The width encroachment (D elta W) also increases rapidly with reducing T-Si. These observations can be explained by the formation of sharp beak and accelerated sidewa ll oxide growth in these devices. A simple guideline is given to optim ize the reoxidation process for different T-Si.