Method for separating sapphire substrate by unit on basis of stress action

Abstract

The invention discloses a method for separating a sapphire substrate by unit on basis of stress action, comprising the following steps: adopting a first type of laser to realize the unit isolation of GaN base epitaxy; ensuring the unit independency of the GaN base epitaxy; meanwhile, utilizing a second type of laser to scan the upper tangential stress between the unit sapphire substrate and adjacent non-scanning unit sapphire substrate; and under the combined action of GaN interface nitrogen pressure and the upper tangential stress, separating and removing the sapphire substrate by unit. Thus, laser stripping finished product rate can be obviously improved.

Description

technical field [0001] The invention relates to a method for removing a sapphire substrate by using a laser lift-off technique, and more specifically relates to a method for separating a gallium nitride-based epitaxial layer from a sapphire substrate. Background technique [0002] At present, most gallium nitride (GaN)-based epitaxial materials are mainly grown on sapphire substrates, and high crystal quality can be obtained through the introduction of buffer layers, so that GaN-based materials can be widely used in various optoelectronic devices and electronic devices. However, the poor material properties of sapphire itself hinder the manufacturing and performance improvement of GaN-based devices. On the one hand, the insulating properties of the sapphire substrate make GaN-based devices generally adopt a lateral structure, that is, different electrodes are fabricated on the same side of the device, which requires the introduction of etching and other processes, which inc...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the above-mentioned problem of low laser lift-off yield, the present invention innovatively proposes a stress-based method for separating sapphire substrates unit by unit, including the following steps:

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