Low-Resistance Titanium Contacts and Thermally Unstable Nickel Germanide Contacts on p-Type Germanium

Ti/p-Ge and NiGe/p-Ge contacts are compared on both planar- and fin-based devices. Ti/p-Ge contacts show low contact resistance, while NiGe/p-Ge devices show short circuit problems due to thermally driven Ni diffusion. Considering the thermal budget in the standard backend of line processing for CMOS, Ti is more suitable for p-Ge devices. A low Ti/p-Ge contact resistivity of
$1.1\times 10^{-8}~\Omega \cdot \textrm {cm}^{2}$
is achieved by using a multi-pulse laser annealing technique for B activation.