LOW-TEMPERATURE FORMATION OF PALLADIUM SILICIDED SHALLOW P(+)N JUNCTIONS USING IMPLANT THROUGH METAL TECHNOLOGY

Abstract

Excellent silicided shallow pin junctions have been successfully achieved by the implantation of BF: ions into thin Pd films on a Si substrate to a dose of 5 x 10(15) cm(-2) and subsequent low-temperature (as low as 500 degrees C) furnace annealing. The formed junctions have been characterized for the respective implantation conditions. In this experiment, the implant energy plays the key role in obtaining a low leakage diode. Reverse current density of about 1 nA/cm(2) and the ideality factor of about 1.03 can be attained by the implantation of BF2+ ions at 100 keV and subsequent annealing at 600 degrees C. The junction depth is about 0.08 mu m, measured by the spread resistance method. As compared with the results of unimplanted specimens, the implantation of BF2+ ions into a thin Pd layer can stabilize the Pd silicide film and prevent it from forming islands during high-temperature annealing. High-temperature stability of palladium silicides and the leakage current mechanism are also discussed in this report.