Patent ID: 6664565
Filing Date: 2003-12-16
Classification: C30B,H01L

Abstract:
A ZnO crystal structure comprising:(a) a sapphire substrate; (b) a low temperature growth ZnO single crystal layer formed on said sapphire substrate at a temperature lower than a conventional single crystal ZnO growth temperature so that in an as -deposited state, said low temperature growth ZnO single crystal layer has grain boundaries that are observable in atomic force microscopy, but shows single crystal characteristics in X-ray detraction or reflection electron beam diffraction, and subjected to a surface planarizing process at a temperature capable of growing single crystals so that the grain size increases and the surface is planarized; and (c) a high temperature growth ZnO single crystal layer formed on said low temperature growth ZnO single crystal layer at a temperature suitable for growing a single crystal so that said high temperature growth single crystal layer shows a narrower XRC peak at the same diffraction angle and a lower broad peak of PL spectra than a layer grown without the low temperature growth ZnO single crystal layer.