GaN-based epitaxial structure and preparation method thereof

Abstract

The invention provides a preparation method of a gallium nitride-based epitaxial structure. The method comprises the following steps: providing a substrate, pretreating the substrate, and growing an aluminum nitride buffer layer on the substrate; growing an AlxGa1-xN buffer layer on the aluminum nitride buffer layer; growing a gallium nitride pressure-resistant layer on the AlxGa1-xN buffer layer;growing a gallium nitride channel layer on the gallium nitride pressure-resistant layer; performing indium-assisted growth of an AlyGa1-yN insertion layer on the gallium nitride channel layer; growing an AlzGa1-zN barrier layer on the AlyGa1y-N insertion layer in an indium-assisted manner; and growing a gallium nitride cap layer on the AlzGa1-zN barrier layer. The electron mobility of the GaN-based epitaxial structure prepared by the preparation method is greatly improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a gallium nitride-based epitaxial structure and a preparation method thereof. Background technique [0002] Gallium nitride (GaN), as a representative of wide bandgap semiconductor materials, has the characteristics of large bandgap, high electron saturation drift velocity, high critical breakdown field strength, high thermal conductivity, good stability, corrosion resistance, radiation resistance, etc. , so gallium nitride has high application value in the fields of high temperature, high frequency and high power microwave devices. In addition, GaN can form an AlGaN / GaN heterostructure with aluminum gallium nitride (AlGaN) due to its excellent electronic properties. The heterostructure interface has a high two-dimensional electron gas (2D EG) density, while 2D EG As the conduction channel in HEMT devices determines the electrical properties of GaN devices, therefo...

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Problems solved by technology

However, due to the large binding energy of Al atoms, it is difficult to migrate on the epitaxial surface, and the temperature of the generally grown AlN insertion layer is low, resulting in a decrease in interface quality and poor overall uniformity, which affects the stability and reliability of radio frequency devices.

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