Inversion
The bulk has to have the lowest potential to ensure reverse biased pn-junctions (no current must flow between drain/source and bulk!)
Vsb = 0 ? in the following we relate all voltages to the source voltage
Vgs > VT ? n-channel is induced (blue area between drain and source).
White area ? depletion region
A current can flow between drain and source, if Vds > 0
- Because the MOSFET is a symmetrical device, source and drain have to be defined: source has always a lower potential than the drain for an n-channel FET!