Power bipolar transistor device with integral antisaturation diode

摘要

A high power bipolar transistor device includes an integral antisaturation Schottky diode resulting from direct contact between the metallic base electrode and the collector region of the transistor. The barrier height of the Schottky diode is chosen so that it turns on at a slightly lower voltage than the collector-base voltage at saturation and diverts excess drive current away from the base to prevent the transistor from becoming fully saturated. The integral Schottky diode may also be used to prevent latch-up in a thyristor device or in a parasitic thyristor which forms part of an insulated gate transistor.