Every software package contains a full set of examples suitable for that version and are installed with the software. If you see examples here that are not in your installation you should consider updating to a later version of the software. These examples can be used by beginners and advanced users for product evaluation, teaching purposes, and self-training.
Required Modules
Victory Device
- 2D Simulator
This example shows the effect of depletion in the poly gate when the doping in the poly is reduced below its maximum level. The I-V curves show that even a doping density of 1e20/cm3 in the poly is not sufficient to prevent depletion, loss of current drive and a shift in the threshold voltage of the n-MOSFET.
The first indication of poly depletion is non ideal C-V curves as shown elsewhere. Reduced doping in the poly gate can be a combination of insufficient implant dose, counter doping of P+ poly and dopant evaporation during uncapped anneals.
The example runs three identical simulations sequentially for simplicity, the only difference being the doping in the poly gate. Three doping levels are simulated, 1e19, 1e20 and 1e21/cm3. At the end of the three simulations, the I-V curves of the n-MOSFET in the region of the threshold voltage are plotted. The effect of poly doping is demonstrated by the increased threshold voltage and reduced current drive with reduced poly doping.
Images
