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

Abstract

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 Ωcm2 with the contact area (Ac) of 4.2 Ωm2 evaluated by cross-bridge Kelvin resistor (CBKR) method. The estimation method of contact resistivity was proposed, and 9.4Ω10−8 Ωcm2 was extracted for the scaled contact area.