Crystal substrate, ultraviolet light-emitting device, and manufacturing methods therefor

Abstract

To fabricate a practically useful non-polar AlN buffer layer on a sapphire crystal plate and manufacture a UV light-emitting device on a non-polar crystal substrate by adopting the crystal substrate as an example, an embodiment of the present invention provides a crystal substrateD comprising an r-plane sapphire crystal plateand an AlN buffer layerD of non-polar orientation. The AlN buffer layer comprises a surface protection layerand a smoothing layer. The surface protection layer suppresses roughness increase on a surface of the AlN buffer layer, and the smoothing layer makes the surface of the AlN buffer layer a smoothed surface. Also provided is a crystal substratecomprising an AlN buffer layerT to which a dislocation blocking layerfor reducing crystallographic defects is added between the surface protection layerand the smoothing layer. In another embodiment a deep UV light-emitting device is provided.