Universal Passivation Effect of (NH₄)₂S_x Treatment on the Surface of III-V Compound Semiconductors

Abstract

The effectiveness of (NH 4 ) 2 S x treatment on the (100) surface of GaP, (Al, Ga)As, InP and InAs was studied in comparison to that on GaAs by means of Auger electron spectroscopy (AES) and reflection high-energy electron diffraction (RHEED). It was concluded that the existence of sulfur atoms bonded to semiconductors prevents the adsorption of oxygen. This phenomenon brings about the metal-dependent Schottky barrier fabricated on the (NH 4 ) 2 S x -treated surfaces, implying the reduction in the interface state density. The structure and effect of the (NH 4 ) 2 S x -treated surface of III-V compounds are qualitatively the same.