MOSFET Grid Example

MOSFET Grid Example

   line x loc=-0.05 spac=0.01   tag=TopOx
   line x loc=0.03 spac=0.001  tag=TopSi
   line x loc=0.04 spac=0.0025
   line x loc=0.06 spac=0.01
   line x loc=0.09 spac=0.005
   line x loc=0.10 spac=0.01
   line x loc=0.12 spac=0.025
   line x loc=0.19 spac=0.05
   line x loc=3.00 spac=0.1    tag=Bottom

This section specifies the vertical grid spacings and line positions. The first line is placed at a position of -0.05um, and is tagged "TopOx". The second line is given a spacing of 10Å and is tagged "TopSi". It is placed at 0.03um. The next lines help control the grid spacing as we go deeper into the silicon. As a rule of thumb, grid should be fine in device simulation in regions with charge. So the grid is fine for the inversion layer and at the bottom of the source and drain junctions. The final line is placed at 3.0um and tagged "Bottom". This line is at a depth deep enough to accommodate the depletion layers.

region oxide xlo=oxi xhi=toe
region silicon xlo=top xhi=bottom
region gas xlo=bottom xho=bottom

The previous three lines specify the regions of the structure. Oxide is placed between the top two grid lines 20Ã… thick. The rest of the device is specified to be silicon. A gas mesh is placed along the back side of the wafer.

init