Interface diffusion and reaction between Ti layer and Si 3 N 4 /Si substrate

A Ti layer of thickness 270 nm was deposited successfully on the surface of Si 3 N 4 /Si substrate using the d.c. sputtering technique. Auger electron spectroscopy (AES) analysis indicates that the Ti layer reduced the native SiO 2 layer that existed on the surface of the Si 3 N 4 film to form TiO x and Si species at the interface during deposition. The interface diffusion and reaction between the Ti layer and Si 3 N 4 /Si substrate was promoted significantly by annealing treatments in the temperature range 300–700 °C in a high vacuum. At temperatures below 600 °C, only very little silicide formed. With increasing annealing temperature, TiSi species formed rapidly. When the temperature reached 700 °C, both TiSi and TiSi 2 species formed in the interlayer. The formation of TiSi and TiSi 2 species was governed mainly by the interface reaction when the annealing time was short. Silicon in the interlayer mainly came from the Si 3 N 4 layer at low temperature or a short annealing time, otherwise it mainly came from the depletion of Si substrate at high temperature or a long annealing time. Copyright © 2001 John Wiley & Sons, Ltd.