SINGLE AND MULTILAYER FERROELECTRIC PBZRXTI1-XO3 (PZT) ON BATIO3

Ferroelectric PbZrxTi1-xO3 (PZT) thin films have been deposited on Pt- coated Si substrates by using r.f. magnetron sputtering. The optimized processing condition to obtain proper stoichiometric PZT, the desired ferroelectric perovskite phase, and better dielectric properties was demonstrated using a PZT target with Pb/(Zr + Ti) ratio of 1.2 and di positing at 350 degrees C, followed bq thermal treatment at 620 degree s C for 30 min. The structural and electrical properties of the PZT la yer were further improved by fabricating a novel multilayer structure which combined the PZT with the nanolayer BaTiO3. The leakage current density was reduced front 2 x 10(-7) A cm(-2) for the single layer str ucture to 2 x 10(-9) A cm(-2) for the multilayer structure at a field of 4 x 10(5) V cm(-1), while maintaining the high relative effective d ielectric constant of 442. The relative dielectric constant of the PZT film in the multilayer structure was calculated to be about 880. (C) 1997 Elsevier Science S.A.