A Reflectometric Study of the Reaction between Si and WF 6 during W‐LPCVD on Si and of the Renucleation during the H 2 Reduction of WF 6

The formation of W through the reduction of by Si is monitored in situ using a wavelength adjustable reflectometer. The reflectance‐time relation can be understood and modeled by assuming island growth and a statistical distribution of the island thickness. The model is supported by SEM and Auger observations. The effect of surface layers like native oxides or a plasma treatment on the inhomogeneous Si consumption by the reaction between Si and (gouging) and its effect on the reflectance‐time relation are understood. The model is also applicable in the case of renucleation during the reduction of . A renucleation step consists of the deposition of Si from followed by the Si consumption by . A renucleation step reduces the surface roughing which occurs during the reduction process.