We researched the reduction of leakage current by Al doping in TiO 2 thin film. During the TiO 2 thin film deposition process, Al 2 O 3 thin film deposition was used for Al doping. XPS analysis showed that the greater the amount of Al doping in TiO 2 thin film, the fewer oxygen vacancies were found. The n-type characteristic of TiO 2 thin films is reduced as oxygen vacancies are reduced. An anatase (211) peak was detected by GIXRD analysis, and crystallinity was reduced with greater Al doping; the full width half maximum showed the crystalline size was reduced. UV-visible analysis showed the energy bandgap increased as the crystalline size became smaller, and I-V measurements showed the current density decreased to 3 × 10 −4 A cm −2 (As-dep TiO 2 : 10 −1 A cm −2 ) with Al doping. The dielectric constant remained above 20 even when doped with Al, confirming the superior properties of Al-doping TiO 2 thin film over conventional TiO 2 thin films.

We study the rutile-TiO2 film deposition with a high-k value using a SnO2 seed layer and a low temperature heat treatment. Generally, heat treatment over 600 ℃ is required to obtain the rutile-TiO2 film. However, By using a SnO2 seed layer, we obtained rutile-TiO2 films with heat treatments as low as 400 ℃. The XPS analysis confirms that the SnO2 and TiO2 film were deposited. The XRD analysis showed that a heat treatment at 400 ℃ after depositing the SnO2 and TiO2 films was effective in obtaining the rutile-TiO2 film when the SnO2 film was thicker than 10nm. The TEM / EDX analysis show that no diffusion in the thin film between TiO2 and SnO2. The dielectric constant of the TiO2 film deposited on the SnO2 film (20 nm) was 68, which was more than twice as high as anatase TiO2 dielectric constant. The current density was 10-4A/cm2 at 0.7 V and this value confirmed that the leakage current was not affected by the SnO2 seed layer.