Preparation method of III-group oxide film based on beveled corner substrate and epitaxial wafer thereof

Abstract

The invention provides a preparation method of a III-group oxide film based on a beveled corner substrate and an epitaxial wafer thereof. The preparation method comprises the following steps of extending a buffer layer (2) on a continuous step-shaped substrate (1) with a beveled corner, preparing an epitaxial layer (3) on the buffer layer (2), wherein the epitaxial layer (3) is a monocrystalline III-group oxide film, the buffer layer (2) and the substrate (1) are heterogeneous, and the buffer layer (2) and the epitaxial layer (3) are homogeneous. By extending the buffer layer on the continuous atomic-scale step-shaped substrate with the beveled corner, adsorption atoms of a reaction source can be promoted to grow at the edge of the step, a consistent-orientation growth mode is formed, a complete monocrystalline buffer layer film is obtained, and then a high-quality monocrystalline epitaxial layer film is formed on the monocrystalline buffer layer film in a homoepitaxial mode. According to the method, the process compatibility is high, the cost for producing the high-quality monocrystalline III-group oxide film is reduced, and the method is convenient to popularize and use.

Description

technical field [0001] The present disclosure relates to the technical field of semiconductors, in particular to a method for preparing a Group III oxide thin film based on an off-cut substrate and an epitaxial wafer thereof. Background technique [0002] Ga 2 o 3 And its homologous oxides are a new generation of ultra-wide bandgap semiconductor materials, which have great application prospects in power electronic devices, microwave devices and deep ultraviolet optoelectronic devices. [0003] High-quality Ga 2 o 3 Thin films mainly rely on homoepitaxial growth, and the required high-quality single crystal Ga 2 o 3 The substrate is expensive and not conducive to mass production. At the same time, homoepitaxial growth and single substrate selection limit Ga 2 o 3 Applications of thin films to fabricate heterojunction devices. However, in the existing planar heteroepitaxial substrates, the source gas molecules can freely diffuse on the substrate plane during the growt...

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Problems solved by technology

[0003] High-quality Ga 2 o 3 Thin films mainly rely on homoepitaxial growth, and the required high-quality single crystal Ga 2 o 3 Substrate, expensive, not conducive to mass production

At the same time, homoepitaxial growth and single substrate selection limit Ga 2 o 3 Application of Thin Films to Fabricate Heterojunction Devices

However, in the existing planar heteroepitaxial substrates, the source gas molecules can freely diffuse on the substrate plane during the growth process, and it is easy to produce Ga substrates with different crystal orientations. 2 o 3 crystal, it is difficult to obtain a complete high-quality single crystal film

And the poor electrical conductivity and thermal conductivity of existing substrate materials limit the application of epitaxial wafers in vertical devices and affect the performance of devices under high current operation

At the same time, the substrate and Ga 2 o 3 The thermal mismatch between them is large, resulting in a large number of defects in the buffer layer and epitaxial layer, making it difficult to obtain high-quality single crystal thin films

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