Metal oxide semiconductor field effect transistors (MOSFET) including deep P-wells and methods of forming same

A method of forming a field effect transistor, the method comprising:

• disposing a drift layer over a substrate;
• doping a portion of the drift layer to form P-well within the drift layer, the P-well including:
• a first portion disposed directly over the drift layer, the first portion having at least one distinct area, each of the at least one distinct areas further comprising a respective doping concentration, and
• a second portion separated from the drift layer by the first portion, the second portion including a second doping concentration distinct from the respective doping concentration of the at least one distinct areas of the first portion, wherein the second doping concentration of the second portion is greater than the respective doping concentration of the at least one distinct areas;
• doping a portion of the second portion of the P-well to form an N-source;
• disposing an oxide layer over the N-source and the drift layer;
• and disposing a gate layer over the oxide layer, wherein the drift layer includes a channel region formed between the second portion of the P-well and the oxide layer, adjacent the N-source.