PREPARATION AND ELECTRICAL-PROPERTIES OF MOCVD-DEPOSITED PZT THIN-FILMS

Strongly [001] oriented lead zirconate-titanate [Pb(Zr(x)Ti1-x)O3] thin films with tetragonal structure (0 < x < 0.52) have been successfully grown on (100)Pt/(100)MgO substrates by using metalorganic chemical vapor deposition (MOCVD). The metalorganic precursors were Pb(C2H5)4, Zr(DPM)4 and Ti(i-OC3H7)4. Scanning electron micrographs showed dense and noncolumnar growth with good surface morphology. The relative dielectric constants at room temperature were 200-350, and appeared to have less dependence on composition x than for PZT bulk ceramics. Typical D-E hysteresis loops which occur with PZT bulk ceramics were observed. Remanent polarizations were 30-40-mu-C/cm2. The coercive field decreased from 65 to 40 kV/cm with increases in Zr content. The pyroelectric coefficients without poling treatment were about 3 X 10(-8) C/cm2 K, showing almost the same value as that of poled PZT bulk ceramics.