STUDY OF INTERFACE ROUGHNESS DEPENDENCE OF ELECTRON-MOBILITY IN SI INVERSION-LAYERS USING THE MONTE-CARLO METHOD

The electron mobility in the inversion layer of a metal-oxide semicond uctor field effect transistor formed on the (100) silicon surface is c alculated by using a Monte Carlo approach which takes into account siz e quantization, acoustic phonon scattering, intervalley phonon scatter ing and surface roughness scattering. Degeneracy is also considered be cause it is important at higher normal effective fields (high gate vol tages). The main emphasis is placed on the influence of the specific a utocovariance function, used to describe the surface roughness, on the electron mobility. Here we compare the mobilities obtained using expo nential and Gaussian autocovariance functions. It is found that the el ectron mobility calculated with roughness scattering rates based on th e exponential function shows good agreement with experiments. The effe ct of the degeneracy and screening on the roughness scattering is also discussed. (C) 1996 American Institute of Physics.