The Electrical Characteristics of GaAs-MgO Interfaces of GaAs MIS Schottky Diodes

Abstract

Many researches pay attention to the metal-semiconductor interface barrier, due to its effect on device. Deliberate growing an interface layer to affect and improve the quality of device, especially metal-insulator-semiconductor (MIS) structures, arouses wide attention. In this paper, Be-doped GaAs was grown on substrate wafer by molecular beam epitaxy (MBE) on purpose before depositing insulator layer, and then MgO film as the dielectric interface layer of Au/GaAs were deposited using atomic layer deposition (ALD) method. The interface electrical characteristics of the metal-insulator-semiconductor (MIS) structures were investigated in detail. The barrier height and ideal factor of GaAs diode parameters were calculated by means of current-voltage (I-V) characteristics. Experimental result showed that along with the increasing of the doping content, the Schottky barrier height increasing, but the ideal factor decrease at first and then increase.