Contact resistivity of shallow junctions formed by implantation through Pt or PtSi

Abstract

The specific contact resistance ( ϱ c ) of PtSi/ p + and PtSi/ n + contacts formed by ion implantation through Pt or PtSi was studied. A simple process to form self-aligned six-terminal Kelvin structure was developed in order to measure the specific contact resistance. For the PtSi/ p + contact system, a ϱ c lower than 1 × 10 −6 ω-cm 2 was achieved by BF 2 + implantation at 40 keV to a dose of 5 × 10 15 cm −2. Increase of dose or energy could further decrease the ρ c to be lower than 5 × 10 −7 ω-cm 2. The ρ c of the PtSi/ n + contact system was lower than that of the PtSi/ p + contact system and a ϱ c of 1 × 10 −7 ω-cm 2 was obtained. These results indicate that although the PtSi-contacted junction is formed at temperatures lower than 800°C, the ϱ c is low enough to satisfy the requirements of submicrometer technology. We suggest that PtSi should be a favorable material to form shallow junctions and contacts simultaneously for future VLSI processes and to satisfy low thermal budget requirement.