An analysis of the charge-transport mechanisms defining the reverse current-voltage characteristics of the metal-GaAs barriers

Reverse current-voltage characteristics of metal-GaAs contacts with a Schottky barrier were measured. Linear portions of the reverse-current dependence on the squared electric-field strength in the space-charge region of diodes were obtained. Such a dependence is related to electron interaction with the lattice vibrations. The reverse current of the Mo-GaAs:Si contacts is analyzed at different temperatures. Results of the analysis showed that measured current-voltage characteristics are controlled by the phonon-assisted electron tunneling from metal into semiconductor with the involvement of a deep center attributed to the EL2 trap. A similar mechanism governs the reverse current-voltage characteristics of the Ni-GaAs:S Schottky diodes.