Effects of high current conduction in sub-micron Ti-silicided films

Modeling and characterization of high current conduction in sub-micron titanium disilicide (TiSi₂) films formed on n⁺/p⁺ silicon and n⁺/p⁺ polysilicon over active or field oxide under DC stress are reported. High current conduction in TiSi₂ films is shown to be strongly affected by the fabrication technology and process conditions. A model has been developed to explain the self-heating effect of silicide films under high DC stress. A parameter B is used to describe the sensitivity of the films to high current conduction. We found that the parameter B is linearly related to the initial resistance of the film, the temperature coefficient of resistance of TiSi₂ and the thermal impedance of the surrounding structures, and the results agree well with the experimental data.