Composite silicide gate electrodes—Interconnections for VLSI device technologies

Abstract

A potentially severe limit on density, performance, and wirability of polysilicon-gate technologies for VLSI applications, is the high resistivity of polycrystalline silicon. Composite structures of highly conductive molybdenum or tungsten disilicide on top of polysilicon (polycide) are shown to be a viable alternative gate electrode and interconnect level. Sheet resistance values of 1-3 Ω/□ for an integrated structure are easily attainable. IGFET devices fabricated to channel lengths of ≥ 1.4 µm show the polycide devices to be indistinguishable from normal polysilicon gate devices.