Ultralow-resistivity CMOS contact scheme with pre-contact amorphization plus Ti (germano-)silicidation

Following the previous study on Si:P [1], we also achieve ultralow contact resistivities (ρ
c
) of ∼2×10
⁻⁹
Ω·cm
²
on Si
0.3
Ge
0.7
:B using the same Ti based pre-contact amorphization (PCAI) plus post-metal anneal (PMA) technique. Similar as on Si:P, low-energy PCAI provides the lowest ρ
c
on SiGe:B. By increasing the B concentration, the PMA temperature required on SiGe:B also matches with that on Si:P. A simple Ti based CMOS contact flow is thus proposed. Several B doping and activation methods on SiGe:B are also compared in this work.