Shallow silicided diodes with LPCVD W plug.

We report results on shallow silicided (CoSi sub 2) diodes. The blanket LPCVD W process utilizing hydrogen reduction of WF sub 6 was used to form contacts to these diodes. Titanium nitride TiN was utilized as a glue-barrier layer, and the deposited W was incorporated into the composite metal layer (Al-W-Tin). The diodes were fabricated in the standard CMOS process sequence. The reverse bias current was measured on both n sup + p and p sup + n diodes and compared to that of standard Al contact devices. The results indicate that W LPCVD process causes some increase in the diode leakage, possibly due to penetration of WF sub 6 through microdefects in the TiN barrier layer.