GENERALIZATION OF THERMIONIC EMISSION THEORY - TEMPERATURE-DEPENDENCE OF GAAS INTERVALLEY GAP FROM MEASUREMENTS ON SCHOTTKY DIODES

We have solved Boltzmann's equation in the case of high fields, velocities and relaxation times as they occur in metal-GaAs contacts. The resultant distribution function is employed to obtain a generalization of the thermionic emission theory. Moreover we have measured the current-voltage and capacitance-voltage characteristics of Cr-(n)GaAs contacts in the temperature range 80-425°K. The experimental data are employed in new models for carrier transport and for excess capacitance in order: (i) to obtain the temperature dependence of some contact parameters such as the barrier height, the apparent Fermi level and the apparent temperature of the electron gas at the interface; (ii) to verify the pinning of the metal Fermi level; (iii) to determine in a new and simple way the GaAs intervalley energy gap E0. A noteworthy result of the theoretical and experimental method is a calculation of the appreciable E0 temperature dependence. © 1979.