METHOD OF MAKING A GATE TURN-OFF THYRISTOR USING A SIMULTANEOUS DIFFUSION OF TWO DIFFERENT ACCEPTOR IMPURITIES

摘要

In a GTO thyristor with high reverse voltage, a negative bevel (6) with a comparatively high bevelling angle ( alpha ) becomes possible as edge contour by splitting the p-type base layer into a central p-type base layer (4) of little depth and high edge concentration and a p-type base edge layer (5) of greater depth and low edge concentration.
The two p-types base layers (4, 5) are preferably produced by simultaneous diffusion of two acceptors having different diffusion constants.