SILICIDE-CAUSED ANOMALOUS REVERSE CURRENT-VOLTAGE CHARACTERISTICS OF COSI2 SHALLOW P(+)N JUNCTIONS

Silicided shallow p (+) n junctions formed by BF2+ implantation into t hin Co films on Si substrates to a low dosage (5 x 10(14) cm(-2)) and subsequent rapid thermal annealing (RTA) or conventional furnace annea ling (CFA) are used to show the impact of silicides on junction charac teristics. CFA results in a lower leakage than RTA at a low bias as 5 V at high temperatures attributable to longer annealing time. All the diodes made by RTA exhibit a hard-breakdown behavior. For CFA 700 degr ees C annealing, however, an anomalously poor reverse I-V behavior ind icative of athermal emission is found at high bias. In addition, the 8 00 degrees C-formed diodes and the CFA-treated 1x10(16) cm(-2) implant ed samples show good reverse characteristics even at high bias. As a r esult, annealing conditions should be properly chosen to reduce the im pact of silicides on shallow junctions.