Effect of O₂ plasma treatment on the properties of SiO₂ aerogel film

In the down-scaling trend of ultra large scaled integration, SiO₂ aerogel film can be a promising material for intermetal dielectric with inherent low dielectric constant. A TEOS-derived SiO₂ aerogel film by spin-coating and supercritical drying has high porosity and large internal surface area which contains the chemical species on the internal surface, such as organic groups, hydroxyl groups, and adsorbed water. An oxygen plasma treatment of SiO₂ aerogel film was introduced to control the internal surface chemical species for applying to intermetal dielectrics. The chemical bonding state of the internal surface, microstructure, and electrical properties of the oxygen plasma treated SiO₂ aerogel film were analyzed. Through the oxygen plasma treatment, the surface chemical groups were effectively eliminated. Also, with the parameter changes of oxygen plasma treatment such as ICP power and bias voltage, micro-structural evolution occurred. Decreases in thickness and particle growth were observed. And the improvement of leakage current behavior was also observed after oxygen plasma treatment.