Equation (4.1) shows the structure of the partial differential
equation system describing the transport of
quantities
within a
segment of the device geometry.
denotes the dependent variables which are the values of the affected
quantities and
is the number of equations.
is either the
electrostatic potential resulting from (4.5) or can be chosen
to be one of the dependent variables
by a corresponding statement in
the input deck.
For a system of
impurities the total net concentration
of all
impurities is given by equation (4.3).
denotes the
charge state of the impurity
(
for neutral impurities,
for
singly ionized acceptors, and
for singly ionized donors).
The electrostatic potential
is determined by the Poisson equation
(4.4)
By assuming vanishing space charge and the applicability of Boltzmann statistics the Poisson equation can be solved explicitly (4.5).