Marked Reduction of the Surface/Interface States of GaAs by (NH₄)₂S_x Treatment

Abstract

MIS capacitors have been fabricated on (NH4)2S x -treated GaAs using a SiO x insulator prepared by conventional resistive-heating evaporation. The MIS interface state density was found to be about 1.2×1011 cm-2·eV-1 in a wide range of the band gap, which is two orders of magnitude less than that on the as-etched GaAs.

Charge transport at the interface of n-GaAs (100) with an aqueous HCl solution: Electrochemical impedance spectroscopy study

“…8). On the other hand, it is known that the density of surface states for GaAs (100) contains several peaks within the semiconductor band gap [19,23]. The absence of distinct features in the dependence of C SS on the applied voltage in the anodic range can be explained by assuming that these surface states are related to intermediate compounds, mobile on the surface and formed in the course of anodic decomposition of the semiconductor [10,12], rather than to the GaAs (100) surface itself.…”

Sulfur-mediated palladium catalyst immobilized on a GaAs surface

“…9,10 (2) Pd-immobilization: once dry, the plates were immersed in a solution of Pd(OCOCH 3 ) 2 (5 mg) in acetonitrile (3 ml) at 80 C for 12 h and washed with acetonitrile (3 ml  3).…”

Surface study of organopalladium molecules on S‐terminated GaAs

“…It is represented that considerable amount of (NH 4 ) 2 S x is deposited on the surface. The peaks completely disappeared after vacuum drying because the excess amount of (NH 4 ) 2 S x evaporated to form a monolayer of S-termination on the GaAs surface [13,14]. The formation of the S-termination by heating at 250…”