Structure using graphite alkene as buffer layer epitaxy GaN (gallium nitride) and preparation method of structure

Abstract

The invention relates to a structure using graphite alkene as buffer layer epitaxy GaN (gallium nitride) and a preparation method of the structure. The method comprises the following steps of: adopting a graphite alkene layer as a buffer layer between the substrate and a gallium nitride epitaxy layer; and inserting a nitride thin layer between the graphite alkene layer and a GaN layer so as to obtain a gallium nitride epitaxy layer with low stress and high quality. The defective rate of LED (light emitting diode) devices is reduced, the quality of the LED devices is increased, and the life cycle is prolonged. The problem of lattice mismatch and thermal expansion coefficient mismatch between the substrate and the gallium nitride are solved effectively.

Description

Technical field [0001] The invention relates to a structure of epitaxial GaN with graphene as a buffer layer and a preparation method thereof, and belongs to the technical field of optoelectronics. Background technique [0002] Gallium nitride material has received more and more attention as a new type of semiconductor material. As a representative material of third-generation semiconductors, gallium nitride has excellent electrical and optical properties. It has the advantages of relatively wide band gap and direct band gap, high temperature and high pressure resistance, and is suitable for use in harsh environments. The main applications of gallium nitride materials are light emitting diodes (LEDs) and high electron mobility transistors. Gallium nitride-based light-emitting diodes can achieve wavelength changes from ultraviolet to red light, covering the entire visible light band, especially the commercialization of gallium nitride blue light-emitting diodes, driving the devel...

AI Technical Summary

Problems solved by technology

However, the existence of the buffer layer can only relieve a part of the lattice mismatch, and the actually grown GaN epitaxial material still has a relatively high density of dislocations.

[0004] Chinese and foreign patent documents have mentioned that the use of materials that are relatively close to the properties of the epitaxial gallium nitride layer to solve the problem of lattice mismatch: Japanese patent JP7312350 "CRYSTAL GROWTH METHOD OF GALLIUM NITRIDE-BASED COMPOUND SEMICONDUCTOR", which discloses A method for epitaxial gallium nitride on a sapphire substrate using an aluminum gallium nitrogen buffer layer. The buffer layer is grown by a metal-organic chemical vapor deposition method, and high-quality gallium nitride materials with a mirror surface can be obtained; US Patent US6495867 "InGaN / AlGaN / GaN Mutillayer Buffer For Growth Of GaN On Sapphire" discloses a composite buffer layer structure, which uses a composite buffer layer of indium gallium nitride, aluminum gallium nitride, and gallium nitride to reduce the mismatch between sapphire and gallium nitride Degree; Chinese patent CN1505843 "GaN-based LED formed on SiC substrate", which discloses a structure and preparation method of a complex buffer layer mainly composed of AlGaN material on a SiC substrate, which solves the problem of silicon carbide Problem of poor material wettability when GaN is epitaxial on substrate

Although the technical means adopted by the above-mentioned several patents can alleviate the lattice mismatch, they cannot alleviate the stress and thermal expansion coefficient mismatch between the substrate and the epitaxial material.

Therefore, during epitaxial growth, the quality of the epitaxial crystal will be reduced due to the presence of large stress, and even cracks will appear.

Images