Monte Carlo study of Si–n-MOSFETs including the quantization of carriers

Abstract 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 shifts into the substrate and the surface potential is lifted compared with the results of the conventional calculation. Thus, all the carriers injected into the inversion layer have energies higher than the ground subband state and remain apart from the surface. The peak position for generated carriers is shown to move towards the source side, resulting in a higher substrate current. All of these tendencies become more prominent with decreasing drain voltage. Hence, the quantization is important for predicting the reliability of Si–MOSFETs, especially those operating at low drain voltages.