Silicides and ohmic contacts

Abstract

Silicides and ohmic contacts are an interesting and important part of integrated circuit technology. The integration of silicides and ohmic contacts in advanced CMOS devices uses knowledge from many different fields; solid state physics for the electrical properties of the contacts, materials science for solid state reactions, oxidation and dopant interactions, wet chemistry for patterning, and plasma chemistry and physics for patterning and deposition. This paper gives an overview of the scientific and technological aspects of silicides and ohmic contacts, including the electrical properties of metal-Si contacts, metal and silicide deposition techniques, metal-Si reactions, silicide patterning processes, silicide stability, and device degradation due to silicides. We focus on silicides and ohmic contacts used in advanced CMOS devices, including NiSi, TiSi2 and CoSi2 salicides, WSi2 and TiSi2 polycides, and W studs. © 1998 Elsevier Science S.A.