Structure and Properties of WSi sub 2 Thin Films for MOS Devices

摘要

Polycrystalline silicone has long been used as the gate and interconnection material in metal-oxide-semiconductor field-effect transistor (MOSFET) integrated circuits, but as the device dimensions are shrinking and circuits are growing larger, the relatively poor conductivity of poly-Si is limiting its performance. As an alternative, tungsten silicide on poly-Si is being considered. No research has yet been reported on the microstructure-properties of this system. In the present research, therefore, the annealing behaviors of coevaporated WSi sub 2 on p-doped poly-Si have been studied by x-ray diffraction, He exp + - backscattering, transmission electron microscopy (TEM), and Auger/SIMS analysis. High temperature annealing of silicide results in crystallization of what appears to be amorphous layers of tungsten silicide as well as diffusion of phosphorous out of the poly-Si. An attempt is made to correlate the physical and chemical properties with device fabrication and performance. (ERA citation 07:061795)