SIMS ON ZNO SURFACES - INFLUENCE OF SPACE-CHARGE ACCUMULATION LAYERS ON SECONDARY ION YIELDS AND MEASUREMENT OF TRUE HYDROGEN CONCENTRATION

On single crystal surfaces of n-conducting ZnO rather strong space charge accumulation layers can be produced by adsorption of atomic hydrogen. It is shown that secondary ion yields depend strongly on this charge carrier concentration at and near the surface. By comparison to electric conductivity measurements it is demonstrated that surface concentrations of hydrogen are proportional to secondary ion yield ratios of type XH±/X±. In the experiments it was further noticed that Na, K, Ca represent common impurities on ZnO surfaces. © 1979.