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

Abstract 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 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.