Quantum effects on the extraction of MOS oxide traps by 1/f noise measurements

1/f noise measurements can be a viable method for the characterization of t he oxide state density in MOSFET's, being directly applicable to submicron- scale devices. In this work we address the impact of electron quantization and mobility fluctuations on the analysis of the lif noise results, assessi ng the precision of the approximations usually introduced in the extraction procedure, Numerical models are employed to account for quantization effec ts, both in the normal and the lateral directions with respect to the Si/Si O2 interface. Mobility fluctuations are analyzed by means of a state-of-the -art model for Coulomb-limited mobility. Results are reported for n-MOSFET' s with a heavy channel doping. It is found that incomplete knowledge of the spatial location and nature (acceptor- or donor-like) of traps causes a su bstantial uncertainty in the extracted value of the absolute trap density.