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.