Preparation and characterization of rf-sputtered SrTiO3 thin films

Electrical and structural properties of strontium titanate (SrTiO3) thin fi lms deposited on Si and GaAs substrates by a conventional radio frequency-m agnetron sputtering technique at different oxygen (O-2) partial pressures a nd substrate temperatures have been reported. Dielectric constant of the as -deposited samples increases with the substrate temperature as well as the O-2 partial pressure. However, it shows a decreasing trend at higher O-2 pa rtial pressure values. When the samples were annealed for 1 h at temperatur es above 500 degrees C the dielectric constant value of the SrTiO3 (STO) fi lms increased by five times and a maximum value of 147 was obtained. The in crease in the dielectric constant value is reflected in x-ray diffraction m easurements with the development of high intensity lines corresponding to S TO phase. The thickness dependence of the dielectric constant is also repor ted. Thin film STO capacitors fabricated with Pt as top and bottom electrod es showed low leakage current densities and a high breakdown voltage of 855 kV/cm suggesting the possibility of considering these capacitors for integ ration with devices. (C) 2000 American Vacuum Society. [S0734-2101(00)12204 -3].