KINETICS OF TUNGSTEN SILICONIZING

Kinetics of tungsten siliconizing in gaseous silane is studied within a wide temperature range T = 1000-1600 degrees C. We determined the P- T regions in which various kinetic reaction regimes and mechanisms of tungsten interaction with silane are realized as well as regions where one-or two-layer diffusion zones of silicides W5Si3 and WSi2 are form ed. In most cases interaction between tungsten and silane is shown to proceed via the diffusion-controlled reaction mechanism, the growth of silicide layers at the initial interaction stages is described by a l inear law, and the siliconizing rate is controlled by heterogeneous si lane pyrolysis on the surface of an appropriate silicide layer.