Electron emission from direct bandgap heterojunction capacitors

The rate of emission of electrons from an inversion layer at the interface between p-type GaAs and undoped Al/sub x/Ga/sub 1-x/As (x=0.38) is measured using a transient capacitance technique at temperatures from 49.8 to 84.4 K and at various gate biases. A model based on physical mechanisms is developed that accurately describes the inversion charge leakage. The model parameters are adjusted within their limits of uncertainty to obtain the optimal fit of present theory to experiment. The fit results in estimation of delta E/sub c/=0.28 eV and tunneling effective mass m*=0.08 m/sup O/, for Al/sub 0.38/Ga/sub 0.62/As. The model is used to predict the storage characteristics of similar devices with lower GaAs doping and with an alternate barrier material.<
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