Influence of substrate bias voltage on the physical, electrical and dielectric properties of RF magnetron sputtered TiO 2 films

Titanium oxide (TiO ₂) finds potential applications in various fields such as solar cells, optical coatings due to its high refractive index and it also has been widely used in memory devices owing to its high dielectric constant. TiO ₂ films have been deposited on p-type silicon (100) substrates by RF magnetron sputtering technique. Thickness, structure and surface morphology of the films were analyzed by using α-step profilometer, Raman spectroscopy and atomic force microscope respectively. Thin film capacitors of the type Al/TiO ₂/Si were fabricated by evaporation of Aluminium on to the TiO ₂ films. The current - voltage and capacitance - voltage characteristics were carried out to understand the electrical conduction and dielectric properties of the deposited films with a stack of Al/TiO ₂/Si. The leakage current density was decreased and capacitance was increased with increase of substrate bias voltage.