SUBSTRATE POTENTIAL EFFECTS ON LOW-TEMPERATURE PREPARATION OF SRTIO3THIN FILMS BY RF MAGNETRON SPUTTERING

SrTiO3 films have been prepared by RF magnetron sputtering at a low su bstrate temperature of 200-degrees-C. The dielectric properties of the films deposited wherein substrate potentials were floated were fairly dependent on the film thickness, which was related to a change of the substrate potential at the initial stage of deposition. In order to c ontrol the substrate potential, positive DC bias voltages were applied on substrates, so that leakage current densities of the films were ma rkedly reduced while their dielectric constants and structural propert ies remained almost the same. A 300-nm-thick film deposited with DC bi as voltages > +5 V exhibited. good dielectric properties with a leakag e current density of 1 X 10(-7) A/cm2 and a dielectric constant of 90.