threshold voltage change as W and L change

Thread Starter


Joined Dec 6, 2007
foe a smic 0.18 process ,in a dc simulation for a opamp, most of the transistors threshold voltage are found to be approximately equal to the value (0.39V )given in the spice model, but for some whose channel are relatively small(180nm for example), there threshold voltage have a big difference. could anyone explain the phenomena? thanks:)