Power device having reduced reverse bias leakage current

Abstract

A power device having vertical current flow through a semiconductor body of one conductivity type from a top electrode to a bottom electrode includes at least one gate electrode overlying a gate insulator on a first surface of the body, a channel region of second conductivity type in the surface of the body underlying all of the gate electrode, a first doped region of the second conductivity type contiguous with the channel region and positioned deeper in the body than the channel region and under a peripheral region of the gate electrode, and a second doped source/drain region in the surface of the body abutting the channel region and adjacent to the gate electrode. When the gate is forward biased, an inversion region extends through the channel region and electrically connects the first electrode and the second electrode with a small Vnear to the area between adjacent P bodies being flooded with electrons and denuded of holes. Therefore, at any forward bias this area conducts as an N-type region. When the gate electrode is reverse biased, the long channel region underlying the full length of the gate electrode reduces reverse leakage current.