LOW-TEMPERATURE FORMATION OF SHALLOW P(+)N JUNCTIONS BY BF2+ IMPLANTATION INTO THIN PD2SI FILMS ON SI SUBSTRATES

Abstract

Excellent silicided shallow p(+)n junctions have been successfully achieved by the implantation of BF2+ ions into thin Pd2Si films on Si substrates to a dose of 5 x 10(15) cm(-2) and subsequent low temperature (even at 550 degrees C) furnace annealing. The formed junctions have been characterized for respective implantation conditions. In this experiment, the implant energy is the key role in obtaining a low leakage diode. Reverse current density of about 3 nA/cm(2) and an ideality factor of about 1.05 can be attained by the implantation of BF2+ ions at 80 keV and subsequent annealing at 550 degrees C. The junction depth is about 0.09 mu m, measured by the spread resistance method. As compared with the results of unimplanted specimens, the implantation of BF2+ ions into a thin Pd2Si layer can stabilize the silicide film and prevent it from forming islands during high temperature annealing.