By neglecting in the six moments transport model (eqns. (2.178) to (2.183)) all
terms containing derivatives, equations for the homogeneous case are obtained
Inserting eqn. (6.4) into eqn. (6.6) and eqn. (6.5) into
eqn. (6.7) yields the equations
which can further be reduced to a bulk relation for the nonMAXWELLian parameter

(6.10) 
Unfortunately, the models for the relaxation times are not accurate enough to obtain a
realistic estimate for
. Therefore the following fit to Monte Carlo data
has been developed

(6.11) 
with
,
, and
. This expression is accurate for doping
concentrations around
but the doping dependence of
is only relevant at lower temperatures (Fig. 6.3).
However, the presented formulation for
did not solve the problem of
anomalous SOI simulation resultspresumably because the decrease of the kurtosis
with increasing temperature occurs too slowly.
M. Gritsch: Numerical Modeling of SilicononInsulator MOSFETs PDF