Composite patterned substrate, preparation method thereof and LED epitaxial wafer

Abstract

The embodiment of the invention discloses a composite patterned substrate, a preparation method thereof and an LED epitaxial wafer. The preparation method of the composite patterned substrate comprises the following steps: providing a plain sapphire substrate; forming at least one dielectric layer on the plain sapphire substrate, wherein the at least one dielectric layer comprises a first dielectric layer which is located at a bottom layer and is in contact with the plain sapphire substrate; patterning the at least one dielectric layer to form a plurality of heterogeneous microstructures; and carrying out wet etching on the first dielectric layer by adopting an etching solution. The chemical reaction rate of the flat sapphire substrate and the etching solution is lower than that of the first dielectric layer and the etching solution. According to the embodiment of the invention, the problem that the C surface of the plain sapphire substrate is easy to be seriously damaged in the existing preparation process of the patterned substrate is solved, and the quality of the C surface for growing the epitaxial material in the composite patterned substrate can be ensured, so that the epitaxial growth defects can be reduced, and the quality of the epitaxial layer can be improved.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of semiconductors, in particular to a composite patterned substrate, a preparation method and an LED epitaxial wafer. Background technique [0002] As a third-generation semiconductor material, gallium nitride has properties such as wide direct band gap, strong atomic bond, high thermal conductivity, good chemical stability (hardly corroded by any acid), and strong radiation resistance. It has broad prospects in the application of optoelectronics, high-temperature high-power devices and high-frequency microwave devices. However, its crystals cannot grow independently at present, and must be attached to the substrate material for nucleation and growth. [0003] At present, the mainstream substrate is a patterned sapphire substrate, that is, a specific pattern is prepared on a sapphire flat sheet for stress release during the growth of gallium nitride; there are many ways of patterni...

AI Technical Summary

Problems solved by technology

However, its crystals are currently unable to grow independently, and must be attached to the substrate material for nucleation and growth

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