Oxygen Gettering Cap to Scavenge Parasitic Oxide Interlayer in TiSi Contacts

Presence of a native oxide interlayer degrades seriously the contact resistivity ( $\rho _{{\text {c}}}$ ) of co-deposited TiSi (CD-TiSi) on Si:P. The oxide cannot be scavenged by the CD-TSi due to its low solid solubility of O. We tackle the problem by capping the CD-TiSi with an O gettering cap. Utilizing a Ti cap and two-step post-metal rapid thermal anneal, we reduce the $\rho _{{\text {c}}}$ of the CD-TiSi on ${2}\times {10}^{{21}}$ cm $^{-{3}}$ doped Si:P by ${\sim }{3}$ times, down to ${\sim }{2} \times {10}^{-{9}}\,\,\Omega \cdot \text {cm}^{{2}}$ . We also demonstrate efficiency of a La cap to scavenge the oxide.