Having determined the values of the principal statistical variables at the corners and center of the acceptable design region, TCAD simulation is used to generate the required characterization data. This is a critically important TCAD application because experimental data is usually unavailable at all process corners.
As stated earlier, no process simulation is required to generate the I-V
and C-V data when using the statistical input variables
selected in this chapter. It is important though to accurately determine
the nominal doping profile. With the limitations of multiple dimensions
process simulation [60], this is best accomplished using the
methodology described in Chapter 4 to extract the 2D doping profile
from nominal device capacitance data. The use of an extracted 2D doping
profile minimizes the uncertainties in device characteristics such as
L and bias-dependent overlap capacitance.
Once the nominal 2D doping profile is obtained a full set of MINIMOS generated
characteristics is used to extract the analytical model parameters by
matching the I-V and C-V data at the center and corners of the acceptable
design space. This is illustrated for the case of the typical device of the
0.5
m CMOS technology as described next.