source voltages between zero and 3V spaced by 0.5 volts for both our default NFET and
our PFET (W/L-5/0.5). This covers the full operating range of our devices. Label each
trace with the VGs voltage used for each curve. For the NFET your plot should look
qualitatively like this:
104
VGSI-VTH
Saturation Region
HLA-ESDA
HLA-ESDA
Vass
Vosz
Vast
To do this you need to use a DC parameterized sweep with two loops, in one loop you are
sweeping VDs and the other you are stepping VGs. To get the PFET characteristic to
look like this you will need to change the signs of the some of the voltages and currents.
b) Plots of the simulation results
Repeat for the PFET
Vos
Careful: getting the PFET scans is trickier than you think, be sure that you cover the
triode and saturation regions.
(need the screenshots for these)
Questions:
For the NFET
a) A legible copy of your simulation schematic, make sure it shows the device length and
width
a) For similar absolute values of the bias voltages the PFET and NFET drain currents are
different, why?
b) Observe how the slope of the curves in saturation change for different Vos. What does
this imply about ro, the small signal output resistance as a function of Ves?
c) What would the maximum current be if instead of a 5 micron wide device you had a 20
micron wide device?
Fig: 1