METHOD FOR PREPARING COMPOSITE SUBSTRATE FOR GAN GROWTH

摘要

The present application discloses method for preparing a composite substrate for GaN growth. The method comprises: first growing a GaN mono-crystalline epitaxial layer on a sapphire substrate, then bonding the GaN epitaxial layer onto a temporary substrate with an epoxy-type instant adhesive, lifting off the sapphire substrate by laser, then bonding the GaN epitaxial layer on the temporary substrate with a thermally and electrically conductive substrate, shedding the temporary substrate, and so obtaining the composite substrate in which the GaN layer of face-up gallium polarity is bonded to the thermally and electrically conductive substrate. When the GaN layer on the sapphire substrate is directly bonded to the thermally and electrically conductive substrate and the sapphire substrate is lifted off by laser, a composite substrate in which a GaN epitaxial sheet of face-up nitrogen polarity is bonded to the thermally and electrically conductive substrate is obtained. The composite substrate prepared in the present invention not only has homo-epitaxy and improves the quality of crystals but also can be used directly for the preparation of LEDs with a vertical structure, and merely uses a thin layer of GaN mono-crystalline , greatly reducing costs and possessing advantages in applications.