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 degrees C for 30 min. The structural and electrical properties of the PZT layer 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 structure 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 dielectric 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.