Gallium nitride heterojunction bidirectional switching device

Abstract

The invention relates to a gallium nitride heterojunction bidirectional switching device, belonging to the field of semiconductor power devices. The invention provides a gallium nitride heterojunctionbidirectional switching device without ohmic contact, which can avoid a series of negative effects caused by high temperature ohmic annealing process. The invention adopts a Schottky source contact and a Schottky drain contact with a low work function metal based on the principle that the similar ohmic contact between the low work function metal and the InAlN / GaN can be formed directly without high temperature annealing; meanwhile, the working condition of the device is changed through two insulated gate structures, so as to realize the bidirectional conduction and bidirectional blocking capability of the bidirectional switching device. Because the gallium nitride heterojunction bidirectional switching device does not have ohmic contact and does not need heavy metals, the technology of the gallium nitride heterojunction bidirectional switching device can be compatible with the traditional CMOS technology.

Description

technical field [0001] The invention belongs to the technical field of semiconductor power devices, in particular to a gallium nitride bidirectional switch device. Background technique [0002] Bidirectional switches with bidirectional conduction current and blocking voltage characteristics are widely used in motor drives, aircraft, AC power supply units, marine electric propulsion, and electric vehicles. The traditional bidirectional switch is composed of two insulated gate bipolar transistors (IGBT) and two power diodes in reverse series, the structure is similar to figure 1 (a), in such a structure, the current will flow through two different devices, and the longer current path will cause a larger turn-on voltage drop, which in turn will cause a higher power loss in the bidirectional switch. In order to reduce the conduction loss of bidirectional switches and improve system efficiency, bidirectional switches based on reverse resistance devices have been proposed in rece...

AI Technical Summary

Problems solved by technology

However, conventional gallium nitride bidirectional switching devices have ohmic contacts, require heavy metals such as gold, and are prepared under high temperature conditions, making the device incompatible with traditional silicon processes

And during the high-temperature ohmic annealing process, the surface of the device will be oxidized, which will lead to the generation of surface states

These surface traps trap electrons, resulting in a large dynamic resistance during dynamic switching of the device

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