Design of lateral IGBT power devices with current sensor

Abstract

MOS-controlled bipolar power devices provide attractive characteristics, such as high current capability, simplicity of low-power gate drive circuitry and fast turn-off characteristics. In this paper, the design of a lateral IGBT with an n/sup +/ anode buffer layer and a p/sup +/ cathode buried layer is investigated. The influence of several internal parameters on the device performance in terms of forward conduction, turn-off, and breakdown were studied. Initially, a current sensor was incorporated as part of the lateral IGBT device structure with its sensing ability evaluated. The sensor contact is placed near the cathode to sense the lateral current and is able to provide a constant current sensing ratio with respect to the wide changes of operating current density and gate voltage. Small variations of the sensing ratios were maintained over the temperature range of 250 to 450 K.