DIELECTRIC PROPERTIES OF RF SPUTTERED BISMUTH TITANATE THIN FILMS.

Crystalline films of Bi//4 Ti//3 O//1 //2 were deposited by RF sputtering in argon:oxygen gas using heated substrates. Using a gas pressure of 20 mTorr, preliminary experiments indicated bismuth loss from the films. This was compensated by enriching the bismuth content in the target. To achieve high dielectric constant and low loss comparable to single crystal values, a substrate temperature of 450 degree C was required. For these conditions, pinhole-free films with permittivity epsilon //R greater than 200 and tan delta less than 2% could be obtained quite reproducibly, suggesting the potential use of this material in thin film capacitors.