Preparation method of gallium nitride single crystal substrate

Abstract

The invention provides a preparation method of a gallium nitride single crystal substrate. The method comprises the following steps: 1) providing a sapphire substrate, and forming a gallium nitride template layer on the sapphire substrate; 2) providing a transfer substrate and a bonding layer, wherein the bonding layer can be converted between a liquid state and a solid state, and bonding the transfer substrate and the gallium nitride template layer by the bonding layer; 3) stripping the gallium nitride template layer from the sapphire substrate; and 4) converting the bonding layer into a liquid state, and carrying out epitaxial growth on the stripped gallium nitride template layer to obtain the thickened gallium nitride single crystal substrate. According to the invention, the transfer substrate and the gallium nitride template layer are bonded through the bonding layer; the bonding layer can be converted between the liquid state and the solid state, in the process of epitaxially generating a gallium nitride single crystal, the bonding layer is in the liquid state, so that the gallium nitride template layer is in a free state, stress can be effectively released, thermal mismatch can be effectively relieved, and the problems of stress accumulation and wafer warping caused in the production process are solved.

Description

technical field [0001] The invention belongs to the field of semiconductor material manufacturing, in particular to a method for preparing a gallium nitride single crystal substrate. Background technique [0002] With the development of science and technology, there are more and more application fields of semiconductor devices with excellent performance such as high frequency, high efficiency and high power. The third-generation semiconductor materials represented by gallium nitride have excellent physical and chemical properties such as wide bandgap, high thermal conductivity, and corrosion resistance, and have broad application prospects in optoelectronic devices and microelectronic devices. [0003] Common gallium nitride devices are fabricated by growing gallium nitride epitaxial layers on heterogeneous substrates to form semiconductor devices. However, due to the use of heterogeneous substrates, there is a lattice mismatch and thermal mismatch between materials, result...

AI Technical Summary

Problems solved by technology

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for preparing a gallium nitride single crystal substrate, which is used to solve the problems of the prior art The continuous accumulation of stress during the growth process of GaN single crystals in medium-sized GaN single crystals leads to the problem of different degrees of warping of GaN single crystal substrates

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