Excellent silicided shallow p+n junctions have been successfully achieved by the implantation of BF2+ ions into thin Pd films on a Si substrate to a dose of 5×1015 cm-2 and subsequent low-temperature (as low as 500° 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/cm2 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° C. The junction depth is about 0.08 µm 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.
- High-temperature stability
- Junction depth
- Low-temperature furnace annealing
- Shallow junction