Self-aligned silicides or metals for very large scale integrated circuit applications

Abstract

The increases in the packing density and the resulting shrinkage of the silicon integrated circuit dimensions led to the investigation and successful application of the deposited refractory silicide layers as the gate and interconnection metallization. The continued shrinking of the device dimensions has now turned attention to further lowering of the resistance at the gate level and to finding a contact metallization for the shallow junctions. Although refractory metals are being considered for the former, self-aligned silicides of cobalt, titanium, platinum, and nickel offer the possibility of satisfying both the gate and interconnection and contact metallization requirements. This paper will review the present status of the refractory silicide and refractory metal technologies and compare them with the upcoming self-aligned silicide technology.