Fabrication of rutile TiO₂ thin films by low-temperature, bias-assisted cathodic arc deposition and their dielectric properties

The use of rutile-type titanium dioxide (TiO₂) thin films as advanced gate dielectrics has been hampered by thermodynamic instability during the high deposition or annealing temperature of 800 °C. In this work, we demonstrate that rutile-type TiO₂ thin films can be produced on p-type Si (100) at lower substrate temperature by means of bias-assisted cathodic arc deposition. The influence of the substrate bias on the microstructural and dielectric characteristics of the TiO₂ thin films is investigated in detail. Our results show that by applying a suitable bias to the Si substrate, as-deposited rutile-type TiO₂ thin films can be obtained at 450 °C. The permittivity of the materials increases significantly from 21 up to 76. The interfacial and electrical properties of TiO₂/Si (100) are also improved. The effects and mechanism of the bias on the microstructural and dielectric characteristics are described.