Normally-closed gallium nitride HEMT device

Abstract

The invention provides a normally-closed gallium nitride HEMT device. The device comprises a heterostructure as well as a source electrode, a drain electrode and grid electrode which are connected with the heterostructure, wherein the heterostructure comprises a first semiconductor layer as a channel layer; a second semiconductor layer as a barrier layer is formed on the first semiconductor layer;a p-type semiconductor layer is formed between the second semiconductor layer and the grid electrode, two-dimensional electron gas is produced between the first semiconductor layer and the second semiconductor layer and disappears right below the p-type semiconductor layer; and a dielectric layer as a passivation layer is settled on the upper surface of the heterostructure, and pre-selected metalions are injected into the dielectric layer right above a region in which the two-dimensional electron gas usually exits. By virtue of each embodiment provided by the invention, the density of the two-dimensional electron of the normally-closed HEMT device can be effectively increased.

Description

technical field [0001] The present application relates to the technical field of semiconductor devices, in particular to a normally-off gallium nitride HEMT device. Background technique [0002] Due to the existence of two-dimensional electron gas between the channel layer and the barrier layer of GaN HEMT (High Electron Mobility Transistor, high electron mobility transistor), GaN HEMT is a normally-on device. [0003] In order to realize the normally closed property of the gallium nitride HEMT device, that is, it is only turned on when there is a forward bias voltage on the gate. In the prior art, a layer of p-type semiconductor is usually placed on the top of the barrier layer, but in order to achieve a reasonable forward gate bias, it is necessary to reduce the thickness of the barrier layer or the content of Al to realize the initial two-dimensional electron gas balance. This will cause the output current intensity of the normally closed HEMT device to be smaller tha...

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Problems solved by technology

This will cause the output current intensity of this normally closed HEMT device to be small, which is smaller than that of the normally open device

[0004] There are at least the following problems in the prior art: the output current intensity of the normally closed GaN HEMT device is small, which is smaller than that of the normally open device

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