Structural and electrical characterizations of Ag-InP(100) interfaces stabilized by antimony

Abstract

The change of the (100) surface of indium phosphide substrates during argon ion bombardment, heat treatments in vacuum, deposition of antimony or silver metallization has been studied by Auger electron spectroscopy and electron energy loss spectroscopy. The formation of P vacancies and metallic In on InP(100) resulting from the breaking of covalent In-P bonds is mainly responsible for ohmic contacts. The InP(100) surface may be stabilized by a deposition of antimony followed by heat treatments in vacuum. The chemical reactivity between indium and antimony leads to the formation of a thin InSb surface layer which prevents In and P from interdiffusion phenomena during the subsequent silver metallization process. An improvement of the I( V) electrical characteristics has been observed for the resulting metal-semiconductor contact.