TiSi(Ge) Contacts Formed at Low Temperature Achieving Around $2 \,\, \times \,\, 10^{-{9}}~\Omega $ cm2 Contact Resistivities to p-SiGe

Abstract

This paper reports ultralow contact resistivities ( $\rho _{c})$ achieved on highly doped p-SiGe with two low-temperature contact formation methods. One method combines precontact amorphization implantation with ~500 °C rapid thermal processing (RTP)-based Ti germano-silicidation; $\rho _{c}$ achieved was $\sim 2.9\times 10^{-9}~\Omega \cdot $ cm2. The other method combines codeposited TiSi—Ti:Si =1:1—with ~450 °C RTP-based Ti silicidation; $\rho _{c}$ achieved was $\sim 1.7\times 10^{-9}~\Omega \cdot $ cm2. When $\rho _{c}$ reaches minimum, the TiSi(Ge) alloy is generally amorphous with embedded small crystallites, similar to the previous observations on pure Si substrates.