Method for growing a gan single crystal film on a buffer layer on a scalmgo4 substrate and performing cooling so that the gan film is peeled from the scalmgo4 substrate

Abstract

The present invention provides a preparation method of a gallium nitride single crystal based on a ScAlMgOsubstrate, comprising following steps: (1) providing a ScAlMgOsubstrate; (2) growing a buffer layer on a surface of the ScAlMgOsubstrate; (3) annealing the buffer layer; (4) growing a GaN crystal on the buffer layer; (5) performing cooling, so that the GaN crystal is automatically peeled off from the ScAlMgOsubstrate. The present invention does not need to use a complex MOCVD process for GaN deposition and preprocessing to make a mask or a separation layer, which effectively reduces production costs; compared with traditional substrates such as sapphire, it has higher quality and a larger radius of curvature, and will not cause a problem of OFFCUT non-uniformity for growing GaN over 4 inches; finally, the present invention can realize continuous growth into a crystal bar with a thickness of more than 5 mm, which further reduces the costs.