Electronics
MOSFET Body Effect Factor – Substrate Bias Effects
The source and body may not be at the same potential. The curve represented as EFi is the Fermi level from the p substrate through the reverse biased source–substrate junction to the source contact. The space charge region width under the oxide increases from the original xd @ threshold value when Read more…
Electronics
MOSFET Depletion Region Width Xd
Gauss’s Law This is the electric field flux With a uniform charge density that is much more wide and long than it is thick you can use the following: So as you progress upwards from 0 the flux increases. Gathering up terms and using Gauss’s law: Now that we Read more…
Electronics
Pao-Sah MOSFET Charge Model Simplified
In the Pao-Sah charge model of the MOSFET the diffusion term cancels out. This should not be a huge surprise because there is no dissimilar semiconductor junction. Current is constant along the channel so let's treat it like a resistor while again ignoring any gate structure.
MOSFET Basics
Resistivity of a plain old block of silicon
What is a MOSFET but a plain old block of silicon with some terminals printed on it. I start here with the most basic of components. Here are the relevant points:
- I want to think about N channel MOSFET so I start with P type material doped at Na=10^16 cm^-3
- Area = A = 1cm x 1cm
- Length = 429cm I chose this because mobility of Boron doping @10^16 = 429cm^2 / V*S