Design and analysis of a new conductivity-modulated power MOSFET

A MOSFET has been developed to offer a performance tradeoff between the ON-resistance, or the forward conduction capability, and the gate turn-on/turn-off switching speed. This conductivity-modulated power DMOS structure (CMDMOS) features a minority-carrier injector adjacent to the current path which allows electrical control of the switching speed/ON-resistance tradeoff. This paper presents an analytical model for the ON-resistance of the device. In this model, the injector hole concentration and the extent of conductivity modulation in the drift region are obtained as functions of the injector current, the drain current, and the device geometry. This work leads to a better understanding of the effect of conductivity modulation, and results in a new power device which provides substantial flexibility in trading off ON-resistance and switching speed.<
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