Thin-substrate double-base high-voltage bipolar transistors
B-TRAN bipolar power transistor devices and methods, using a drift region which is much thinner than previously proposed double-base bipolar transistors of comparable voltage. This is implemented in a high-bandgap semiconductor material (preferably silicon carbide). Very high breakdown voltage, and fast turn-off, are achieved with very small on-resistance.
1. A power semiconductor device which includes:
both an n-type emitter/collector region, and also a p-type base contact region, on each of both first and second surfaces of a p-type semiconductor die; wherein each said emitter/collector region is positioned to act as an emitter of a bidirectional switch while the other emitter/collector region acts as a collector thereof;
wherein the material of the semiconductor die has a bandgap greater than two eV;
and wherein the rated OFF voltage of the device, divided by the resistivity of the semiconductor die in ohm-cm, and further divided by the thickness in microns of the die between the emitter/collector regions on the first and second surfaces, yields a value greater than two amps per cm-μm;
wherein the base contact region on the first surface is not electrically connected to the base contact region on the second surface, except through the semiconductor die itself; and
wherein the emitter/collector region on the first surface is not electrically connected to the emitter/collector region on the second surface, except through the semiconductor die itself.
2. The device of claim 1 , wherein the semiconductor die is silicon carbide.
3. A power semiconductor device which includes:
both a first-conductivity-type emitter/collector region, and also a second-conductivity-type base contact region, on each of both first and second surfaces of a second-conductivity-type silicon carbide semiconductor die;
and wherein the rated OFF voltage of the device, divided by the resistivity of the semiconductor die in ohm-cm, and further divided by the thickness in microns of the die between the emitter/collector regions on the first and second surfaces, yields a value greater than two amps per cm-μm;
wherein the base contact region on the first surface is not electrically connected to the base contact region on the second surface, except through the semiconductor die itself; and
wherein the emitter/collector region on the first surface is not electrically connected to the emitter/collector region on the second surface, except through the semiconductor die itself.
4. The device of claim 3 , wherein the semiconductor die is p-type.