17-11-2012, 04:01 PM
CMOS Inverter
1CMOS Inverter.pdf (Size: 859.57 KB / Downloads: 94)
Device Parameters and Dimensions
Table 1 gives the device specifications that were supplied for both pMOS and nMOS devices.
All parameters were then converted in to the CGS unit system for consistancy. Any cell which
contains N/A means that that parameter is not applicable for that specific device.
A table with all the SPICE keywords and the corresponding symbols along with the units
SPICE expects can be found on page 365 in the Casey textbook. Futhermore k is defined as
Boltzmann’s Constant and has a value of 8.616×10−5 eV/K.
MOSFET Parameter Calculation
All calculations were performed with the aid of a MatLab script which is included in section
8. The first SPICE parameter to be calculated was the threshold voltage, VT. The first step is
to calculate the work function for the n+-polysilicon gate and p+-polysilicon gate followed by
the work function of the p-type and n-type substrates. Equation 1 shows how the work function.