Preparation method of large-size nonpolar A-side GaN self-supporting substrate

Abstract

The invention provides a preparation method of a large-size nonpolar A-side GaN self-supporting substrate, and belongs to the field of photoelectronic device preparation. Compared with the prior art, the preparation method comprises steps of forming a mask film on a substrate epitaxial growth surface; allowing the ask layer to form a graph structure via photoetching and etching technique; then growing a nonpolar A-side GaN thick film; removing the mask layer via GaN horizontal integration or corrosion so as to form a porous structure at the bottom of the GaN thick film; and stripping the GaN thick film from the substrate via the corrosion method, thereby obtaining the nonpolar A-side GaN self-supporting substrate. According to the invention, the A-side GaN substrate in large size can be easily prepared; during the process for stripping the A-side GaN thick film from the substrate, a complex and expensive laser stripping device is not required; and the preparation method is simple in technique, lower in cost and easy to produce and use in large scale.

Description

technical field [0001] The invention belongs to the field of preparation of optoelectronic devices, and in particular relates to a preparation technology of a large-size non-polar A-plane GaN self-supporting substrate. Background technique [0002] Group III-V nitride semiconductor materials represented by GaN have been widely used in the preparation of optoelectronic devices, such as light-emitting diodes, semiconductor lasers, and photodetectors. However, the GaN-based device structure is mainly prepared along the C-axis orientation (that is, the [0001] crystal orientation). The spontaneous polarization and piezoelectric polarization along the C-axis lead to a large built-in electric field inside the device, causing quantum wells to The electron and hole wave functions are separated, which leads to a decrease in the photoelectric conversion efficiency of the device. In order to eliminate the adverse effect of the polarization effect on the photoelectric conversion efficie...

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Problems solved by technology

However, on the one hand, this method requires the most complex and expensive laser lift-off equipment, and the cost is high; on the other hand, during the laser lift-off process, a gas with a high pressure will be generated at the bottom of the GaN thick film, resulting in the cracking of the GaN thick film, and the yield rate is low. high

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