Method for preparing gallium nitride (gan) single-crystal substrate with edge metal mask technology

Abstract

The present disclosure provides a method for preparing a gallium nitride (GaN) single-crystal substrate with an edge metal mask technology. The method includes: preparing a metal mask ring on a composite epitaxial substrate, epitaxially growing a GaN single-crystal sacrificial layer in a confined manner, performing separation with interlayer decoupling of single-crystal graphene through an in-situ temperature gradient method to obtain a self-supporting GaN single-crystal sacrificial layer, epitaxially growing a GaN single-crystal thick film in a diameter expanded manner, and performing chemico-mechanical trimming on the GaN single-crystal thick film to obtain a stress-free self-supporting GaN single-crystal substrate. The metal mask ring is compatible with the GaN single-crystal preparation process (hydride vapor phase epitaxy (HVPE)), and efficiently catalyzes decomposition reaction of the nitrogen source. While prohibiting edge growth of the GaN single-crystal thick film, the present disclosure improves a crystalline quality of the GaN single-crystal substrate.