Dopant Segregation and Nickel Stanogermanide Contact Formation on $\hbox{p}^{+} \hbox{Ge}_{0.947}\hbox{Sn}_{0.053}$ Source/Drain

P
⁺
Ge
_1-x
Sn
_x
is a promising source and drain (S/D) stressor material for Ge p-MOSFETs, and an S/D material in Ge
_1-x
Sn
_x
channel p-MOSFETs. In this paper, we investigate the dopant segregation (DS) effects in the stanogermanidation of p
⁺
Ge
_0.947
Sn
_0.053
(boron-doped). A study comparing the contact resistance
R
_C
of nickel stanogermanide [Ni(Ge
_1-x
Sn
_x
) or Ni(GeSn)] contact on p
⁺
Ge
_1-x
Sn
_x
and nickel germanide (NiGe) contact on p
⁺
Ge was performed. A more pronounced DS effect is achieved during the stanogermanidation in comparison with the NiGe/p
⁺
Ge control.
R
_C
is 44% lower in the Ni(Ge
_1-x
Sn
_x
)/p
⁺
GeSn structure as compared to the NiGe/p
⁺
Ge control. The reduced
R
_C
is attributed to a more significant DS effect and the lower bandgap of Ge
_1-x
Sn
_x
as compared with Ge.