Comprehensive study of Ga activation in Si, SiGe and Ge with 5 × 10−10 Ω·cm2 contact resistivity achieved on Ga doped Ge using nanosecond laser activation

Ga diffusion and activation in Si, SWGe
_0.6
and Ge are studied comprehensively. Optimal Ga activation conditions for Si
_0.4
Ge
_0.6
and Ge feature a low thermal budget: Ga is highly activated at 400°C in Ge and at 500°C in SWGe
_0.6
using a 1min rapid thermal annealing (RTA); the activation is further boosted using short-duration high-temperature nanosecond laser activation (NLA). A low Ti/p-Ge contact resistivity (pc) of 1.2×10
^-9
Q-cm
²
is approached using Ga doping and 400°C RTA activation, while a record-low pc for p-Ge down to 5×10
^-10
Qcm
²
is achieved using NLA for Ga activation.