Evaluation of contact resistivity of PtHfSi to p-Si(100) with dopant segregation process

We have investigated the contact resistivity of PtHf-alloy silicide (PtHfSi) to p-Si(100) with dopant segregation (DS) process. After the patterning of SiO
₂
hard mask and heavily doped p
⁺
diffusion region formation on n-Si(100) substrates, 20 nm-thick PtHf-alloy thin film with 10 nm-thick HfN encapsulating layer was in-situ deposited utilizing PtHf-alloy target by RF magnetron sputtering at room temperature. Then, BF
₃
ion implantation was carried out for DS followed by the silicidation at 500°C/20 min in N
₂
/4.9%H
₂
ambient. After the Al electrode formation, sintering process was carried out at 400°C/20 min in N
₂
/4.9%H
₂
ambient. Ultra-low contact resistivity was achieved for fabricated PtHSi such as 7.6×10
^-8
Ωcm
²
with the contact area (Ac) of 4.2 Ωm
²
evaluated by cross-bridge Kelvin resistor (CBKR) method. The estimation method of contact resistivity was proposed, and 9.4Ω10
^-8
Ωcm
²
was extracted for the scaled contact area.