Metal stanogermanide contacts with enhanced thermal stability for high mobility germanium-tin field-effect transistor

We report a novel metal stanogermanide contact metallization process for high-mobility germanium-tin (Ge
0.947
Sn
0.053
or GeSn) channel p-MOSFETs. Nickel-Platinum (NiPt) alloy was used to react with GeSn to form a multi-phase Ni and Pt stanogermanide [NiGeSn+Pt
x
(GeSn)
y
] contact on epitaxial Ge
0.947
Sn
0.053
. Rapid thermal annealing of co-sputtered Ni and Pt on GeSn/Ge (100) at temperatures from 350 °C to 550 °C in N
2
was used for the stanogermanide formation. Compared with nickel stanogermanide (NiGeSn) contact, the Pt-incorporated contact, i.e. NiGeSn+Pt
x
(GeSn)
y
, exhibits enhanced thermal stability in a wide range of formation temperatures.