Crack free PLZT (9/65/35) thin films were prepared by a metallic organic decomposition (MOD) process on Pt(111)/Ti/SiO2/Si(100) and sapphire(001) substrates respectively. The films on Pt/Ti/SiO<sub>2</sub>/Si substrates present highly (111)-preferred orientation while they display highly (110)-preferred orientation on sapphire substrates. The microstructure of the films were investigated and discussed. Ferroelectric properties of PLZT thin films on Pt/Ti/SiO<sub>2</sub>/Si(100) substrates have been studied. Typical slim polarization-electric field hysteresis loops were observed. As the film thickness increasing, the remanent polarization P<sub>r</sub> increases and the coercive electric field E<sub>c</sub> drops. The influence of film thickness on optical transmittance and refractive index n<sub>r</sub> were examined by the films deposited on sapphire substrates. The n<sub>r</sub> at 510nm wavelength shows an increasing tendency with film thickness increasing. Great stress aggregated during the film processing is thought to be an important reason which results in the variations of optical properties dependent on the film thickness.
Crack-free polycrystalline PbZr<sub>0.53</sub>Ti<sub>0.47</sub>O<sub>3</sub> (PZT(53/47) thick films (1~30μm) with peroviskite structure have been prepared from a dip-coating process. The influence of withdrawal speed and precursor solution concentration on the morphology of the films was examined. The effects of the substrate characteristics on the film phase structure and microstructure were investigated and evaluated. The ferroelectric and dielectric properties have been examined and discussed. PZT (53/47) thick films on Pt/Ti/SiO<sub>2</sub> wafer and Pt/Ti foil substrates all exhibit excellent electric properties, Pr: 32~34 μmC/cm<sup>2</sup>; Ec: 32~35kV/cm, ε<sub>r</sub> 900~940; tanδ: 0.02~0.04. These materials promise a good application in micro-devices including micro-pump, micro-actuator, etc.
A modified sol-gel process with acetate based precursor solutions for Sr-doped barium titanate thin films is presented. A four-step heating procedure was employed to prepare the Ba<SUB>0.8</SUB>Sr<SUB>0.2</SUB>TiO<SUB>3</SUB> thin films. The thermal decomposition and crystallization temperatures of the precursors were determined by means of FTIR, TGA/DTA, and XRD measurements. The nonlinear C-V characteristics are due to strong depletion that can not originate from the BST/electrode interface, but must come internally from the BST films.
PZT thin films were prepared by a modified sol-gel technique. Au was used as a top electrode of PZT capacitor. An influence of the process of the top electrode on the PZT ferroelectric capacitor was investigated. The relationship between remnant polarization, coercive electric field and the conditions of thermal treatment for the top Au electrode was discussed. The diffusion of Au and the interface between PZT and Au were analyzed by Auger spectra too. The proper heat treatment condition for optimal ferroelectric performance in the PZT capacitor was suggested.
Iridium oxide (IrO<SUB>2</SUB>) thin films were successfully grown on SiO<SUB>2</SUB>/Si(100) substrate by DC magnetron reactive sputtering method with an Ir target (99.99% purity). The effects of sputtering parameters and annealing conditions on the crystalline nature and morphology of IrO<SUB>2</SUB> thin films were discussed. High orientation at (110) or (200) of IrO<SUB>2</SUB> thin films were occurred by annealed films. For fatigue properties, PZT thin films using an IrO<SUB>2</SUB> electrode have largely improved than that using a Pt/Ti electrode.
PbZr<SUB>0.40</SUB>Ti<SUB>0.60</SUB>O<SUB>3</SUB> (PZT) thick films are prepared on Pt/Ti/SiO<SUB>2</SUB>/Si substrate by a sol gel based 0 - 3 composite method. The influence of processing variable including powder characteristics, solvents feature and annealing condition is investigated. Microstructure and electric property of PZT thick films are examined and analyzed. Optimum parameters of process are suggested. PZT thick film of 10 micrometers thickness with excellent ferroelectric and dielectric properties has been obtained (Pr 24 (mu) C/cm<SUP>2</SUP>, (epsilon) <SUB>r</SUB> 680 at 1 kHz.