DEPOSITION AND SURFACE CHARACTERIZATION OF HIGH-QUALITY SINGLE-CRYSTAL GAN LAYERS

Recently, using low pressure metalorganic chemical vapor deposition we grew extremely high quality single crystal GaN films over basal plane sapphire substrates. Optimization of the buffer layers and the total film thickness played a key role in determining the electrical, optical, crystalline and surface qualities. In this communication we present the surface characterization results for these high quality GaN layers. Reflection high energy electron diffraction, low energy electron diffraction (LEED), and electron energy loss spectroscopy data are presented for clean GaN surfaces. The cleaning procedure was developed using Auger electron spectroscopy analysis. These electron diffraction data indicate the grown surface to be excellent single crystal GaN with a wurtzite structure. To the best of our knowledge ours is the first reported LEED data for single crystal GaN.