Utilization of NiSi2as an interconnect material for VLSI

The applicability of NiSi
2
as an interconnect material was investigated using narrow (5 µm- × 2600-µm) lines. 2500-Å-thick silicide lines were thermally oxidized to form a passivation layer of SiO
2
for the next metallization level. Isolation of more than 50 V for 2200-Å SiO
2
is achieved. The interconnect resistivity following the oxidation is 1.2-1.4 Ω. The maximum current capability of the lines was found to be > 5 × 10
⁶
A/cm
²
and their stability under prolonged high current densities was demonstrated. We propose a scheme to increase the local metallization-level density using NiSi
2
as an interconnect.