Effect of Ion Irradiation on the Formation of Ni, Cr and Pt Silicide

Abstract

ABSTRACTThe influence of Xe+, As+ and Si+ irradiation on the Ni, Cr and Pt-silicide formed upon subsequent thermal annealings has been investigated. Helium MeV backscattering spectrometry and x-ray diffraction have been used to analyze the samples. The effect of silicon-metal interface contamination has been observed using an intentionally formed thin silicon oxide layer. The oxide layer was thick enough to prevent thermal silicide formation in unirradiated samples. In irradiated samples, the silicide forms thermally in spite of the presence of this oxide layer for Ni and Cr, but not for Pt. Similar results were obtained for Xe+, As+ and Si+ irradiations. We attribute this effect to ion mixing of the interfacial layer. The differences between results obtained with Ni, Cr and Pt are discussed. These results demonstrate that a low-dose irradiation can render the process of silicide formation upon thermal annealing tolerant to interfacial impurities. On the other hand, we also show that ion irradition can inhibit Pt and Ni silicide formation.