Method for lift-off of light-emitting diode substrate

A method for lift-off of a light-emitting diode (LED) substrate, comprising:

• 1) providing a sapphire substrate;
• 2) forming pattern structures on a surface of the substrate, the pattern structures being periodically distributed;
• 3) depositing a blocking layer on the patterned sapphire substrate, and performing polishing on the blocking layer so that the entire upper surface of the blocking layer is flush with surfaces of projections of the patterned sapphire substrate;
• 4) growing a GaN epitaxial layer on the patterned sapphire substrate, so that cavity structures are formed between the GaN epitaxial layer and the patterned sapphire substrate, wherein the GaN epitaxial layer comprises an N-GaN layer, a quantum well layer and a P-GaN layer;
• and
• 5) eroding a sidewall of the GaN epitaxial layer by wet etching, so that the GaN epitaxial layer is separated from the sapphire substrate.