Thorough analysis of quantum mechanical effects on MOS structure characteristics in threshold region

Threshold voltage shift due to quantum mechanical effects (QMEs) are studie d for both n- and p-MOS structure in the paper. Subband structure and carri er distribution are formulated for both type of MOS structure in effective mass approximation. QMEs on threshold voltage shift are thoroughly analyzed based on the model. Carrier distribution in subbands for both n-MOS and p- MOS are calculated and analyzed from density-of-states point of view. Model results for n- and p-MOS structure are compared with experimental and full -band self-consistent calculation results and show good coincidence. It is proved that at least in threshold region, effective mass approximation has similar accuracy as the full-band self-consistent method to predict the inf luence of QMEs MOS structure characteristics. (C) 2000 Elsevier Science Ltd . All rights reserved.