Investigation of Ultrathin Ni Germanosilicide for Advanced pMOS Contact Metallization

Ultrathin Ni germanosilicide liner(<;50 Å) is employed in advanced pMOS contact metallization in this work. Due to the intrinsic high work function, the NiSi
_x
Ge
_y
/p
⁺
-SiGe:B contacts show improved specific contact resistivity (ρ
_c
) with respect to conventional TiSi
_x
Ge
_y
/p
⁺
-SiGe:B ones. It is further demonstrated that the ρ
_c
of NiSi
_x
Ge
_y
/p
⁺
-SiGe:B contacts is correlated with both Ni thickness and post metal anneal (PMA). Utilizing Ge preamorphization implant (Ge PAI) followed by B ion implant (B I/I), the active concentration of B dopants is enhanced from 1 × 10
²⁰
cm
^-3
for reference to 6 × 10
²⁰
cm
^-3
. Consequently, a remarkably lowered ρ
_c
of ~7.42 × 10
^-9
Ω·cm
²
is achieved for NiSi
_x
Ge
_y
/p
⁺
-SiGe:B contacts, where Ni layer is 20 Å and PMA temperature is 500 °C.