Surface Preparation of Single Crystals for ZnO Homoepitaxy

Abstract

For the homoepitaxial growth of ZnO it is inevitable to obtain a regular crystalline single crystal surface prior to growth. Commercially available, hydrothermally grown ZnO single crystals show amorphous surfaces due to mechanical cutting and polishing. Here we present the results of a thermal treatment on these ZnO single crystals. After annealing, a regular crystalline oxygen terminated surface can be obtained. Changes in surface roughness, residual defect concentration and electrical properties can be shown. The bulk crystallinity though was not affected.

Polarization dependence of ZnO Schottky barriers revealed by photoelectron spectroscopy

“…ZnO single crystals with c-axis orientation with and without buffer layers have been used. Prior to buffer layer deposition, the crystals were annealed for one hour at 1150 • C in air according to the procedure suggested by Neumann for homoepitaxial ZnO growth [47]. Oxygen was added to the process gas during buffer layer deposition in order to reduce the oxygen vacancy concentration.…”