Determination of ultra-thin oxide voltages and thickness and the impact on reliability projection

Abstract

In this work, the quantum interference (QI) technique was extended to determine oxide thickness down to about 30/spl Aring/ for both inversion and accumulation for dual-poly gate FET structures. We also applied this method to determine oxide voltages at high voltages (FN regime) since oxide fields can be readily obtained from this technique. At low and intermediate voltages, the Berglund integration technique was used to extract surface potentials and oxide voltages from CV measurements. In addition, these experimentally determined results are compared to the QM calculation. We have used these three techniques to comprehensively investigate MOSFET structures in both inversion and accumulation for ultra thin gate oxide. Finally, the impact of accurate oxide voltages and thickness comprehending quantum effects on reliability projection are discussed.