Atomic layer deposition for rutile structure TiO₂thin films using a SnO₂seed layer and low temperature heat treatment

We study the rutile-TiO₂film deposition with a high-kvalue using a SnO₂seed layer and a low temperature heat treatment. Generally, heat treatment over 600 °C is required to obtain the rutile-TiO₂film. However, By using a SnO₂seed layer, we obtained rutile-TiO₂films with heat treatments as low as 400 °C. The XPS analysis confirms that the SnO₂and TiO₂film were deposited. The XRD analysis showed that a heat treatment at 400 °C after depositing the SnO₂and TiO₂films was effective in obtaining the rutile-TiO₂film when the SnO₂film was thicker than 10 nm. The TEM/EDX analysis show that no diffusion in the thin film between TiO₂and SnO₂. The dielectric constant of the TiO₂film deposited on the SnO₂film (20 nm) was 67, which was more than twice as high as anatase TiO₂dielectric constant (Anatase TiO₂dielectric constant : 15-40). The current density was 10^-4A cm^-2at 0.7 V and this value confirmed that the leakage current was not affected by the SnO₂seed layer.