Field plates on two opposed surfaces of double-base bidirectional bipolar transistor: devices, methods, and systems
AssigneeIdeal Power Inc.
InventorsWilliam C. Alexander, Richard A. Blanchard
Life of this patent
Estimating the term…
Abstract
Dual-base two-sided bipolar power transistors which use an insulated field plate to separate the emitter/collector diffusions from the nearest base contact diffusion. This provides a surprising improvement in turn-off performance, and in breakdown voltage.
Claims8
A method for switching a power semiconductor device having a first and a second n-type emitter/collector region, located respectively on first and second opposite surfaces of a p-type semiconductor die, and a first and second p-type base contact region, located respectively on the first and second surfaces of the semiconductor die, comprising:
- in the ON state, driving base current through one, but not both, of the first and second p-type base contact regions to thereby allow passage of current between the first and second n-type emitter/collector regions through the semiconductor die;
- wherein, on each surface, the base contact region and the emitter/collector region are laterally separated by a vertically extended conductive field plate, which field plate is completely insulated from any adjacent semiconductor material by a dielectric material, and is connected to the emitter/collector region on the same surface through a common electrode;
- and
- in the OFF state, not driving base current through any of the first and second p-type base contact regions;
- whereby peak electric field near a junction between the p-type semiconductor die and one of the first and second n-type emitter/collector regions is reduced due to capacitive coupling between the corresponding insulated field plate and the volume of the p-type die, and a breakdown voltage of the semiconductor device is thereby increased.
A method for switching a power semiconductor device having a first and a second p-type emitter/collector region, located respectively on first and second opposite surfaces of an n-type semiconductor die, and a first and a second n-type base contact region, located respectively on the first and second surfaces of the semiconductor die, comprising:
- in the ON state, driving base current through one, but not both, of the first and second n-type base contact regions to thereby allow passage of current between the first and second p-type emitter/collector regions through the semiconductor die;
- wherein, on each surface, the base contact region and the emitter/collector region are laterally separated by a vertically extended conductive field plate, which field plate is completely insulated from any adjacent semiconductor material by a dielectric material, and is connected to the emitter/collector region on the same surface through a common electrode;
- and
- in the OFF state, not driving base current through any of the first and second n-type base contact regions;
- whereby peak electric field near a junction between the n-type semiconductor die and one of the first and second p-type emitter/collector regions is reduced by capacitive coupling between the corresponding insulated field plate and the volume of the n-type die, and a breakdown voltage of the semiconductor device is thereby increased.
Dependencies are inferred from the claim text.