Preparation method of low-on-resistance high-threshold-value voltage enhancement type GaN device

Abstract

The invention discloses a preparation method of a low-on-resistance high-threshold-value voltage enhancement type GaN device. The preparation method specifically comprises the steps of performing epitaxial growth of a buffer layer, a channel layer, an inserting layer and a barrier layer on a substrate in sequence; preparing a selective growth mask layer; performing etching on an external channel selective growth mask layer; performing selective epitaxial growth of an external channel layer; removing a selective growth mask; preparing a selective growth mask layer; performing etching of a gate selective growth region mask layer; performing selective growth of the barrier layer; removing the selective growth mask layer and the external channel layer thereon; preparing source and drain metals and alloy; and preparing a gate metal. The enhancement type GaN device has the advantages of low on-resistance, high threshold value voltage and uniformity, high freedom degree of internal and external channel materials, no dynamic characteristic degradation problem of the device caused by loss and defects, and the like.

Description

technical field [0001] The invention belongs to the technical field of semiconductor device preparation, and in particular relates to a preparation method of a low on-resistance high threshold voltage enhanced GaN device. Background technique [0002] GaN wide bandgap semiconductor material has excellent characteristics and has significant advantages in the development of high-performance power devices. In particular, the characteristics of high critical breakdown field strength and high electron saturation drift rate of GaN material make it have important application prospects in the development of high operating frequency and high power switching devices. [0003] For power switching devices, in order to ensure the safety of the power system, the device needs to be in a normally closed state when it is not working. The GaN power switching device implemented by the commonly used AlGaN / GaN heterojunction structure is in the normally-on state. [0004] At present, the metho...

AI Technical Summary

Problems solved by technology

The current p-GaN cap layer threshold voltage modulation technology, because the material is grown at one time, the thickness of the barrier layer under the p-GaN cap layer is very thin, generally below 15nm, and the Al composition of the barrier layer It is also very low, resulting in a large square resistance in the area without the p-GaN cap layer, which seriously affects the conduction characteristics of the device

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