Growth of rutile-TiO2 thin films via Sn doping and insertion of ultra-thin SnO2 interlayer by atomic layer deposition

Rutile-TiO2 thin films have potential for use in high-k applications, such as dynamic random-access memory capacitors; however, they are difficult to realize without using noble-metal-based oxide substrates. Therefore, we proposed a new approach for the preparation of rutile TiO2 by a small amount of Sn doping and the insertion of ultra-thin SnO2 to achieve enhanced dielectric performance without using noble-metal-based electrodes. It was confirmed that the crystallinity of rutile TiO2 was remarkably enhanced in Sn-doped TiO2 formed on an ultra-thin SnO2 interlayer. Moreover, 10 nm-thick Sn-doped TiO2 thin film on a 1-nm SnO2 interlayer exhibited a high dielectric constant of about 80.