Schottky contact diameter effect on the electrical properties and interface states of Ti/Au/p-AlGaAs/GaAs/Au/Ni/Au Be-doped p-type MBE Schottky diodes

Schottky diodes based on Be-doped p-type AlGaAs were grown by molecular beam epitaxy and their current-voltage (I-V) and capacitance-voltage (C-V) characteristics measured. The Schottky and Ohmic contacts are Ti/Au and Au/Ni/Au, respectively. The effect of the Schottky contact diameter on I-V and C-V characteristics was studied. To elucidate this effect, the Schottky diode figures of merits and interface states are extracted from I-V and C-V characteristics, respectively. It was found that interface states density increases with increasing Schottky contact diameter then saturates beyond 400 mu m. The frequency dependence of the C-V characteristics was also related to these interface states. The results of this present study can help choosing the right Schottky contact dimensions.

Automated summary

In this study, Schottky diodes based on Be-doped p-type AlGaAs were grown and their current-voltage and capacitance-voltage characteristics were measured. The effect of the Schottky contact diameter on the device characteristics was investigated, and the figures of merit and interface states were analyzed. The results showed that the interface state density increased with increasing contact diameter and saturated beyond 400 μm. The frequency dependence of the capacitance-voltage characteristics was also related to these interface states.