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

Abstract

Schottky diodes based on Be-doped p-type AlGaAs were grown by molecular beam epitaxy (MBE) 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 µm. 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.