Patent ID: 6600193
Filing Date: 2003-07-29
Classification: H01L

Abstract:
A power MOSFET comprising:a semiconductor substrate of a first conductivity type; an epitaxial layer overlying the substrate, a trench being formed in the epitaxial layer; and a gate positioned in the trench and electrically isolated from the epitaxial layer by an insulating layer which extends along a bottom and a sidewall of the trench; the epitaxial layer comprising: a source region of the first conductivity type, the source region being located adjacent a top surface of the epitaxial layer and the sidewall of the trench; a body of the second conductivity type; and a drain-drift region of the first conductivity type extending between the substrate and the bottom of the trench, the doping concentration of the drain-drift region increasing monotonically with increasing distance below the trench.