Characterization of sol-gel multicoated thick Pb(Zr-0.52, Ti-0.48)O-3 films on platinized silicon substrates for microdevices applications

The microstructures and electrical properties of thin and thick Pb(Zr-0.52, Ti-0.48)O-3 (52/48 PZT) films for microdevice applications with thicknesses from 480nm to 2.3 mum on 350nm Pt(111)/40nm Ti/300nm SiO2/Si 525 mum substrates fabricated by a sol-gel multicoating process were investigated. These PZT films showed dense and homogeneous surface microstructures. The crystalline structures of 480-nm-thick PZT films showed a (111) preferred orientation over (100), (200) and (110) orientations. The intensity ratios of (100) and (200) to (111) increased at PZT film thicknesses greater than 480 nm. By Auger electron spectroscopy, small- composition-variation peaks at an interval of approximately 120 nm at interfaces produced by each PZT coating process of 480 nm PZT films were found. Dielectric constants increased from 825 to 880 at 100 kHz and PZT film thicknesses from 480 nm to 2.3 mum. The P-r and E-c of 2.3-mum-thick PZT films were about 30 muC/cm(2) and 58kV/cm, respectively. The e(31,f) of 1-mum- and 2mum-thick PZT films was characterized by the fabricated e(31,f) measurement system before and after poling.