PtSi-Induced Junction Leakage

PtSi formation on polysilicon contacts to shallow n+-p junctions causes high reverse leakage currents, due to Pt or PtSi penetration at isolated sites in the polysilicon. The junction penetration density depends on the PtSi anneal temperature and ambient, and is minimized by using either very high (550°C or above) or very low (300°C) temperature anneals in nonoxidizing ambients. The penetration is probably due to a nonuniform reaction between Pt and polysilicon. © 1989, The Electrochemical Society, Inc. All rights reserved.