Thermally robust TiSi/sub 2/ on heavily doped polycrystalline silicon over severe topography

Abstract

Using TiSi/sub 2/ to strap polysilicon over severe topography is hampered by the non-conformality of sputter deposited titanium (Ti) films. Thinning of the Ti translates into regions with thin silicide which degrade drastically when subject to 900 degrees C anneals. Etching back a thick polysilicon film to the desired thickness planarizes the surface for Ti deposition and eliminates the influence of underlying topography. The fabrication process outlined provides a final TiSi/sub 2/ sheet resistance approximately 2 Omega / Square Operator , after a 900 degrees C anneal in O/sub 2/.<>