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

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] A method for separating a sapphire substrate unit by unit based on stress, the preparation steps are as follows:

[0025] Such as figure 2 As shown, an N-type GaN-based semiconductor layer, an active layer and a P-type GaN-based semiconductor layer are epitaxially grown sequentially on a sapphire substrate 100 by metal organic chemical vapor deposition (MOCVD) to form a GaN-based epitaxial thin film 110 .

[0026] Such as image 3 As shown, the GaN-based epitaxial layer 110 is scribed and extended to the sapphire substrate 100 by using a laser scriber (wavelength 355nm). The size of the laser lift-off spot is similar, and the depth of the laser scribing is 30 microns, that is, to realize the GaN-based epitaxy unitization, the generated gas escape window 120, and the formation of the unit sapphire stress release point 130. The plan view is as foll