DIELECTRIC (PB0.91LA-0.09)(MG0.25NB0.40TI0.35)O-3 THIN-FILMS ON PT TIELECTRODES PREPARED BY RF MAGNETRON SPUTTERING/

(Pb0.91La0.09) (Mg0.25Nb0.40Ti0.35)O-3 (abbreviated PLMNT) thin films were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering deposition. The phase formation and dielectric properties of as-depos ited films were studied as a function of substrate temperature and dep osition time. Perovskite PLMNT films were successfully obtained at tem peratures greater than or equal to 520 degrees C. The dielectric const ant (k) decreased with increasing substrate temperature or decreasing deposition time. This phenomenon was explained by the formation of a l ow-k interface layer of TiO2. A 1 mu m thick film prepared for deposit ion at 520 degrees C had shown a moderately high dielectric constant o f similar to 2600 accompanied by a low dielectric loss (tan delta < 0. 03). In addition, the films exhibited a relaxer-type dielectric charac teristic, i.e. a broad dielectric peak appeared at room temperature an d the peak shifted to a high temperature when the measuring frequency was raised; however, the films still possessed a good dielectric stabi lity against frequency.