Interaction of amorphous MoNi_x alloys with silicon

Abstract

The interaction of amorphous MoNi_x alloys with silicon has been investigated by glancing-angle x-ray diffraction, Auger-electron spectroscopy, and sheet-resistance measurements in the temperature range 500-700°C. Mo-rich alloys (Mo₈₀Ni₂₀ and Mo₆₅Ni₃₅) were found to react with silicon at ∼550°C while nickel-rich alloys (Mo₃₂Ni₆₈) react at ∼500°C to form silicides. In Mo-rich alloys, the initial reaction occurs due to out-diffusion of nickel from the alloy and in-diffusion of silicon into the alloy, while in nickel-rich alloys the initial reaction occurs due to out-diffusion of nickel only. In the initial phase of the reaction, a mixture of several crystalline phases of molybdenum and molybdenum and nickel silicides is observed. At higher temperature, however, a two-layer structure MoSi₂ +NiSi(NiSi₂)/ NiSi(NiSi₂)/ Si(100) is formed in both cases.