Thermal formation of SiO₂ films over NiSi, NiSi₂ and CoSi₂ via silicide decomposition

Abstract

The thermal oxidation of NiSi, NiSi2 and CoSi2 layers on silicon substrates causes the formation of surface films of SiO2 while the silicide layers are preserved. This is shown to occur via a mechanism of silicide decomposition followed by metal diffusion and recombination. In the disilicides, a measurable fraction of the silicon atoms diffuse together with the metal atoms. The process responsible for the uphill diffusion of the silicon atoms is thought to be similar to oxidation-enhanced diffusion. © 1983.