Preparation method of semiconductor structure, self-supporting gallium nitride layer and preparation method of self-supporting gallium nitride layer

Abstract

The invention relates to a preparation method of a semiconductor structure, a self-supporting gallium nitride layer and a preparation method of the self-supporting gallium nitride layer. The preparation method of the semiconductor structure comprises the following steps: providing a heterogeneous substrate; forming a film layer on the back surface of the heterogeneous substrate, wherein the thermal expansion coefficient of the film layer is smaller than that of the heterogeneous substrate; the heterogeneous substrate and the film layer are heated to the gallium nitride growth temperature, and the heterogeneous substrate protrudes towards the front face so that the front face of the heterogeneous substrate can be the protruding front face; a gallium nitride layer is formed on the front face of the protrusion of the heterogeneous substrate at the gallium nitride growth temperature, and the gallium nitride layer is in a protrusion shape. According to the manufacturing method of the semiconductor structure, before the gallium nitride layer is formed, the film layer with the thermal expansion coefficient smaller than that of the heterogeneous substrate is formed on the back face of the heterogeneous substrate, the protruding heterogeneous substrate can be manufactured, the gallium nitride layer can be formed on the protruding heterogeneous substrate subsequently, and after the gallium nitride layer is peeled off, the semiconductor structure can be manufactured. And under the influence of internal dislocation, the gallium nitride single crystal substrate with low warping degree can be spontaneously recessed to obtain the gallium nitride single crystal substrate with low warping degree.

Description

technical field [0001] The present application relates to the field of semiconductor technology, and in particular, to a method for preparing a semiconductor structure, a self-supporting gallium nitride layer and a method for preparing the same. Background technique [0002] Compared with traditional substrate materials, gallium nitride has the advantages of large band gap, high breakdown voltage, high thermal conductivity, high electron saturation drift speed, strong radiation resistance and good chemical stability. The material system with the highest electro-optical and photoelectric conversion efficiency. [0003] Due to the difficulty in preparing gallium nitride single crystal substrates, gallium nitride single crystal substrates are generally prepared by the method of heteroepitaxial growth of gallium nitride materials on heterogeneous substrates such as sapphire, silicon carbide, silicon, and gallium arsenide. , and then peeled off from the foreign substrate by a pe...

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Problems solved by technology

[0004] However, when growing on a heterogeneous substrate, due to the lattice mismatch between the heterogeneous substrate and the GaN growth process, a large number of dislocations will be generated during the growth of the GaN epitaxial layer, making these heterogeneous materials There is a very high density of crystal defects in the epitaxial layer of gallium nitride on the surface, which causes the gallium nitride after stripping to be concave in the absence of external force, forming a bow; Difficulty introducing substrates into device and chip manufacturing processes

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