Determination of highhyphen;fieldhyphen;enhanced emission rates with the constant capacitancehyphen;voltage transient technique

摘要

We propose a new method for determining the trap level, doping concentration profiles, and enhanced emission rates caused by a high field which is accurate even in the presence of highhyphen;trap concentrations with a nonuniform profile. The constant capacitancehyphen;voltage transient technique is applied in this method. The amplitude of the transient voltage and the reversehyphen;bias voltage at the beginning of the emission cycle are used for the determination of trap level and doping concentration profiles, respectively. The field enhanced emission rate is determined from the initial slope of the transient signal. The midgap level in GaAs is measured in order to test this method. The effects of both junction leakage current and freehyphen;carrier tail on the trap concentration and emission rate measurements are discussed together with the highhyphen;field effect.