Of Pzt Thin Film Crystallization Kinetics Of The Process

Owing to its excellent dielectric, piezoelectric and ferroelectric properties, PbZr1–xTixO3 (PZT) with perovskite structure is an attractive material for MEMS devices such as microsensor, microactor and NVFRAM. PZT thin film based on Si integration circuit has become a hot issue in microelectronics and material science. Aiming the annealing effects on the crystallization quality, microstructure and electric property, the dissertation had touched the following aspects: First, amorphous Pb(Zr0.48Ti0.52)O3 thin film was prepared on the Pt/Ti/SiO2/Si substrate by RF-magnetron sputtering method. Annealing by rapid thermal annealing (RTA) and conventional furnace annealing (CFA), the study focus on the effects of heating rate, duration time and annealing temperature on the crystallization and growth of PZT thin film. The results show that the thin film with (100)-texture occurred below the heating rate of 10 ℃/s; the (110)-texture occurred between the heating rate of 10 ℃/s and 20 ℃/s; the (111)-texture occurred when the heating rate was above 20 ℃/s. Furthermore, the heating rate was faster; the (111)-texture intensity was stronger. It was first time to investigate the crystallization behavior during the initial crystallization state by observing ferroelectric domain by means of PFM. Based on a series of experiments, the critical nucleation temperature of PZT thin film was determined at 550 o C. The initial duration time for nuclei growth was between 20 seconds and 40 seconds. Once the nuclei were formed, the crystal growth was very quick along the interface and spontaneously polarized to form round in shape ferroelectric domains. By calculation of the domain area of the thin film annealed at 550 o C for 60 seconds, the crystallization ratio was 4.6±0.2%. By means of PFM, it was found that the ferroelectric domain was in relation to the microstructure of thin film. It was first time to observe the occurance of the herringbonelike morphology ferrodomain in (100)-texture thin film at the interface between positive and negative polarization, which was due to the effect of strong depolarization field. While the (110)-texture PZT film with a large number of 90O ferroelectric domains occurance was believed not to meet the NVFRAM devices demands due to the ferroelectirc fatigue pinned by 90O domain wall. By investigating the ferroelectric and dielectric properties of the Pt/PZT/Pt/Ti/SiO2/Si structure capacitor, it was found that the film annealed by RTA at 650℃demonstrated prominent P-E curves and C-V character compared with the films annealed by CFA. The remnant polarization was as high as 40μc/cm2 and the coercive field was only 70kv/cm. The dielectric constant was 235 at 10kHz and the...