InGaN Layers Grown on Al2O3/ZnO Substrates Prepared by Atomic Layer Deposition

摘要

Atomic layer deposition (ALD) of Al_2O_3 is used as a transition layer on ZnO substrates before III-Nitride growth by metalorganic chemical vapor deposition (MOCVD). This transition layer is being used to minimize Zn diffusion from the substrate, protect the ZnO surface from H_2 back etching, and promote high quality nitride growth. ALD-Al_2O_3 films were grown at 100°C and then annealed in a furnace at various times at 1100°C for crystallization of the transition layer. XRD results showed both Al_2O_3 and ZnAl_2O_4 phases at different intensities for 20 and 50nm ALD-Al_2O_3 films. In addition, high indium concentration InGaN layers have been successfully grown on the Al_2O_3/ZnO) substrate. This work shows that a short annealing time for the ALD-Al_2O_3 layer will be optimal for InGaN growth.