Gan-si heteroepitaxial structure and preparation method

Abstract

In the GaN-Si heteroepitaxial structure and preparation method of the present invention, a groove is formed in a Si substrate, and a local SOI substrate is formed at the bottom of the groove, so that the stress generated during the epitaxial process of the GaN layer can be absorbed by the local SOI substrate, Lower Al x Ga 1‑x The thickness of the N transition layer can reduce the growth process time, reduce the process cost, and improve the thermal conductivity. At the same time, the local SOI buried oxide layer can improve the breakdown voltage of the GaN device, and can reduce the loss and crosstalk in RF applications; The insulating sidewall on the sidewall of the groove can effectively isolate the epitaxially grown GaN layer and reduce the difficulty of the process; in the groove of the Si substrate, the area-selective epitaxial growth of the GaN layer can reduce the difficulty of the process; thus, the present invention can be used in large-scale applications. Heteroepitaxial uniform, high-quality GaN layer on a Si substrate.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and relates to a GaN-Si heteroepitaxial structure and a preparation method. Background technique [0002] As a representative of the third-generation semiconductor materials, gallium nitride (GaN) has many excellent characteristics such as high critical breakdown electric field, high electron mobility, high two-dimensional electron gas concentration, and good high-temperature working ability. Therefore, GaN-based third-generation semiconductor devices, such as high electron mobility transistors (HEMTs) and heterojunction field effect transistors (HFETs), have been applied, especially in fields requiring high power and high frequency such as radio frequency and microwave. has obvious advantages. [0003] GaN epitaxial film growth usually uses SiC, sapphire, and GaN as substrates, but these substrates are relatively expensive, and it is difficult to form large-sized wafers, such as 8 inches...

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Problems solved by technology

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a GaN-Si heteroepitaxial structure and a preparation method, which are used to solve the difficulty in the prior art of heteroepitaxial homogeneous, Problems with High Quality GaN Thin Films

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