MONTE-CARLO STUDY OF SI-N-MOSFETS INCLUDING THE QUANTIZATION OF CARRIERS

The drain and substrate currents of a Si-n-MOSFET are analyzed with a two-dimensional window Monte Carlo simulator that includes a new model for the quantization of carriers at the silicon-insulator interface. By including the quantization, the peak depth of the carrier density s hifts into the substrate and the surface potential is lifted compared with the results of the conventional calculation. Thus, all the carrie rs injected into the inversion layer have energies higher than the gro und subband state and remain apart from the surface. The peak position for generated carriers is shown to move towards the source side, resu lting in a higher substrate current. All of these tendencies become mo re prominent with decreasing drain voltage. Hence, the quantization is important for predicting the reliability of Si-MOSFETs, especially th ose operating at low drain voltages. (C) 1998 Published by Elsevier Sc ience Ltd. All rights reserved.