The electron mobility in the inversion layer of a MOSFET, formed on th
e (100) silicon surface, is calculated by using a Monte Carlo approach
which takes into account size quantization, acoustic phonon scatterin
g, intervalley phonon scattering and surface roughness scattering, Deg
eneracy is also considered because it is important at higher normal ef
fective fields (high gate voltages). The main emphasis is placed on th
e influence of the specific autocovariance function, used to describe
the surface roughness, on the electron mobility, It is found that the
electron mobility calculated with roughness scattering rates based on
the exponential function shows a good agreement with experiments, Devi
ce simulation of a MOSFET is carried out to demonstrate the usefulness
of the present model, where 3D electron states are taken into account
in addition to the 2D electron states.