Chemomechanical polishing of gallium arsenide and cadmium telluride to subnanometre surface finish. Evaluation of the action and effectiveness of hydrogen peroxide, sodium hypochlorite and dibromine as reagents

Abstract

Aqueous hydrogen peroxide and sodium hypochlorite in the pH range 7–9 are more effective Chemomechanical polishing reagents for gallium arsenide than is dibromine in methanol. Sodium hypochlorite is an acceptable alternative to hydrogen peroxide for gallium arsenide: it also produces good-quality surface finishes on cadmium telluride over the same pH range. The results of dip–etch and polishing reactions, studied using [82Br]-labelled dibromine, atomic absorption spectroscopy (AAS) and pH or concentration variation, are used to propose a model for Chemomechanical polishing of these materials.