Orientation dependence of ferroelectricity of epitaxially grown Pb(Zr/sub x/Ti/sub 1-x/)O/sub 3/ thin films prepared by metalorganic chemical vapor deposition

摘要

Epitaxial PZT films with [001]- and [100]-, [101]-,[110]- and [111]-orientations were grown on [100]SrRuO/sub 3///[100]SrTiO/sub 3/, [110]SrRuO/sub 3///[110]SrTiO/sub 3/ and [111]SrRuO/sub 3///[111]SrTiO/sub 3/ substrates, respectively. The two composition films with Zr/(Zr+Ti) ratios of 0.42 and 0.68 were prepared with the Pb/(Pb+Zr+Ti) ratio of 0.5. Well-saturated and good square shape hysteresis loops with a large ferroelectricity of the remanent polarization (Pr) above 40 /spl mu/C/cm/sup 2/ were observed for all films. The Pr increased in the following order: [101]-, [111]- and [001]-orientations for the film with the Zr/(Zr+Ti) ratio of 0.42 and [100]-, [110]- and [111]-orientations for the Zr/(Zr+Ti) ratio of 0.68. On the other hand, the Ec value mainly depended on the Zr/(Zr+Ti) ratio and not on the orientation of the film, the Ec value of the film with a Zr/(Zr+Ti) ratio of 0.42 was larger than that of 0.68. The saturation behavior did not strongly depend on the orientation, especially for the films with the Zr/(Zr+Ti) ratio of 0.42. The [101]-oriented film with the Zr/(Zr+Ti) ratio of 0.42 and [100]- and [111]-oriented films with 0.68 did not show deterioration up to 10/sup 10/ switching cycles.