Patent ID: 8063442

Claim:
A trench gate power MOSFET comprising: a drift region of a first conductivity type over a substrate of the first conductivity type; an active region comprising: an active well of a second conductivity type extending to a predetermined depth within the drift region; a plurality of gate trenches extending through the well region; and a plurality of source regions of the first conductivity type flanking sides of the plurality of gate trenches; a termination region surrounding the active region, comprising: a termination well of the second conductivity type extending deeper into the drift region than the active well; and a resistive element coupled to the termination well, wherein during a UIL switching event upon occurrence of avalanche breakdown in the termination region an avalanche current starts to flow in the termination region, and when the avalanche current reaches a predetermined level the resistive element induces a portion of the avalanche current to flow through the active region and a remaining portion of the avalanche current to flow through the termination region.