Patent ID: 7067363

Claim:
A method for forming a semiconductor device comprising: forming spaced apart active areas in a semiconductor substrate and defining a JFET area therebetween, the JFET area also forming a channel between the spaced apart active areas; and forming a gate oxide on the semiconductor substrate and comprising a first portion having a first thickness on the active areas and at a periphery of the JFET area, and a second portion having a second thickness on a central area of the JFET area, the second thickness being greater than the first thickness, wherein forming the gate oxide comprises forming an oxide pad on the active areas and on the channel, forming a nitride layer on the oxide pad, forming a photoresist layer on the nitride layer except over a portion of the JFET area corresponding to the second portion of the gate oxide, removing the exposed nitride layer, implanting dopants through the exposed oxide pad while using the photoresist as an implant window for forming an enrichment region in the JFET area under the second portion of the gate oxide, and removing the photoresist layer.