Method for manufacturing gallium nitride single crystalline substrate using self-split

摘要

The present invention relates to a method for manufacturing a gallium nitride single crystalline substrate, including (a) growing a gallium nitride film on a flat base substrate made of a material having a smaller coefficient of thermal expansion than gallium nitride and cooling the gallium nitride film to bend convex upwards the base substrate and the gallium nitride film and create cracks in the gallium nitride film; (b) growing a gallium nitride single crystalline layer on the crack-created gallium nitride film located on the convex upward base substrate; and (c) cooling a resultant product having the grown gallium nitride single crystalline layer to make the convex upward resultant product flat or bend convex downwards the convex upward resultant product and at the same time to self-split the base substrate and the gallium nitride single crystalline layer from each other at the crack-created gallium nitride film interposed therebetween.