Effect of atomic hydrogen on the properties of metal-GaAs Schottky barrier contacts

The effect of treatment with atomic hydrogen on the properties of GaAs and the characteristics of Au−GaAs Schottky barrier contacts has been studied in terms of the ideality coefficient n of the I-V characteristics, the barrier height ϕ _b , and the reverse breakdown voltage V_r at 10 μA. The source of the atomic hydrogen was a generator based on an arc reflected Penning discharge with a self-heating element. It has been shown that there is an optimal treatment regime (temperature (T_tr) 200–250°C; duration (t_tr) 5 min) for which n and V_r reach a corresponding minimum and maximum. It is proposed that with lower T_tr and t_tr there is nonuniform etching of the surface oxides and with higher it is possible to have nonuniform etching of the GaAs itself. The barrier height depends on the treatment regime in a more complicated way but on the whole decreases. The effect of passive impurities (decrease in the charge carrier concentration) is already pronounced at T_tr=100°C and changes relatively little with further growth of the temperature. Annealing (reactivation of impuritics) is observed for T≥250°C with sufficiently slow cooling of the sample after treatment. State Scientific-Manufacturing Enterprise for NII Semiconductor Devices. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 115–121, August, 1997.