The Effect of (NH4)2S Treatment on the Interface Characteristics of GaAs MIS Structures

Abstract
MIS capacitors prepared on the (NH4)2S-treated GaAs substrate showed a marked reduction in the density of the dominant pinning levels near 0.6 eV below the conduction band. The annealing effect on the interface characteristics was also investigated. Analyses by means of secondary ion mass spectroscopy (SIMS) and Auger electron spectroscopy (AES) indicate that sulfur atoms at the interface stabilize the oxygen-free GaAs surface both electronically and thermally.