Preparation method of GaN substrate

Abstract

The invention discloses a preparation method of a GaN substrate, wherein the preparation method belongs to the field of optoelectronic device preparation. According to the preparation method, a GaN film, an InGaN film, an AlGaN film, an AlN film or an InN film or nanometer columns are epitaxially grown on a sapphire substrate on which carbon nanotubes are laid for forming a transition layer; a carbon nanotube laying range exceeds the edge of the substrate by 200 mu m-1 mm; then a composite substrate is arranged below laser for bearing irradiation; the carbon nanotubes which exceed the edge of the substrate facilitate gradual decomposition of the carbon nanotubes or GaN under laser radiation from the edge to the central part and discharging of generated gas; holes (with diameters of 200-800nm) remain at occupation positions of the carbon nanotubes; and finally a thick GaN film is grown, thereby obtaining a thick GaN film substrate or obtaining a self-supporting GaN substrate through a substrate removing process or a self-separation process. The preparation method of the GaN substrate has advantages of simple operation, easy control of technological conditions, low price and high convenience in large-scale batch production. Different substrates can be selected. Furthermore the preparation method supports a plurality of substrate separation processes.

Description

technical field [0001] The invention belongs to the field of preparation of optoelectronic devices, and relates to a preparation method of a GaN substrate. Background technique [0002] Group III nitride semiconductors have gradually developed into a new generation of lighting sources due to their advantages such as long life, energy saving, environmental protection, rich colors, safety and stability. GaN-based semiconductor devices are developing rapidly and have broad market prospects. However, due to the limitation of heteroepitaxy, lattice mismatch and thermal mismatch make the preparation of high-quality GaN materials very difficult. In particular, high-brightness white LEDs, blue LDs, and high-power, high-frequency power devices urgently need homoepitaxial technology to reduce the defect density of the active layer and improve the thermal and electrical conductivity of the substrate. [0003] Due to the large lattice mismatch and thermal mismatch, the stress continuo...

AI Technical Summary

Problems solved by technology

In order to reduce the stress accumulation in heteroepitaxy, technologies such as insertion layer and lateral epitaxy are applied to the crystal growth process. Because these two technologies have high requirements on the process, the process is relatively complicated, and they are easily affected by the process and make GaN The crystal quality of the substrate material suffers and the yield is not high

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