THERMALLY STABLE, LOW-LEAKAGE SELF-ALIGNED TITANIUM SILICIDE JUNCTIONS

A thermally stable, low-leakage-current, self-aligned titanium silicide junction has now been fabricated. Ar+ sputter etching of Si substrate prior to Ti film deposition followed by two-step rapid thermal annealing in N2 ambient are essential for realization of thermal stability up to 900°C in the titanium silicide layer. It is confirmed that the Ar+ sputter etching can reduce oxygen contamination at the Ti/Si interface. Consequently the titanium silicide layer could be kept extremely flat, with 60 nm thickness with specific resistivity of 19.3 µΩ. cm, even after 900°C, 30 min annealing. The junction leakage current was less than 2.1 nA · cm−2 at reverse bias of 5.0V for n+/p junction. © 1990, The Electrochemical Society, Inc. All rights reserved.