CRYSTALLOGRAPHIC ORIENTATION CONTROL FOR FERROELECTRIC SBT AND SBTN THIN-FILMS FROM PHOTOSENSITIVE MOD SOLUTIONS

SBT and SBTN thin film capacitors on Pt/Ti/SiO2/Si have been fabricate d from photosensitive MOD solutions with the composition Sr0.8Bi2.35Ta 2-xNbx (x=0.0-0.8). Films prepared by a conventional spin-on and annea l process are essentially randomly oriented, while films that received UV radiation before annealing exhibit c-axis orientation. The degree of c-axis orientation is enhanced by short pyrolysis times. Ferroelect ric properties were characterized by hysteresis and pulse measurements . A higher Qsw and lower V(90%) were measured for films with random or ientation in comparison with films having the same composition but c-a xis preferred oriented. The c-axis orientation can be controlled by su bstrate pre-annealing. UV irradiated SET and SBTN films with random or ientation can be prepared on the substrates that are pre-annealed at 6 50 degrees C.