Influence of deep surface levels onC–U schottky doping profiles of n-GaAs VPE layers

Origin of anomalous peaks in CU Schottky doping profiles of n-GaAs VPE layers is investigated. Using the constant capacitance method, it is demonstrated that relaxation effects related to the peak originate in deep traps on the surface. The emptying of the traps is shown to be due to tunneling, thermal excitation, or the Frenkel-Poole effect depending on temperature and electrical field. The last effect is most probably responsible for the appearence of the false peak.