A new channel-doping technique for high-voltage depletion-mode power MOSFET's

A new channel-doping technique for high-voltage depletion-mode double-diffused MOSFET (DMOSFET) is demonstrated. The technique that is used is channel doping performed at the surface of the laterally diffused body region in a self-aligned manner. Decrease of the breakdown voltage due to decrease of the threshold voltage is successfully prevented by using the new technique. A 1050-V DMOSFET was experimentally fabricated with a negative threshold voltage of -2 V.