CONTACT RESISTIVITY OF SHALLOW JUNCTIONS FORMED BY IMPLANTATION THROUGH PT OR PTSI

Abstract

The specific contact resistance (rho(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 rho(c) lower than 1 x 10(-6) OMEGA-cm2 was achieved by BF2+ implantation at 40 keV to a dose of 5 x 10(15) cm-2. Increase of dose or energy could further decrease the rho(c) to be lower than 5 x 10(-7) OMEGA-cm2. The rho(c) of the PtSi/n+ contact system was lower than that of the PtSi/p+ contact system and a rho(c) of 1 x 10(-7) OMEGA-cm2 was obtained. These results indicate that although the PtSi-contacted junction is formed at temperatures lower than 800-degrees-C, the rho(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.