Rapid crystallization of ferroelectric lead zirconate titanate thin films by microwave heating

Pb(Zr0.52Ti0.48)O3(PZT) thin films were coated onto Pt/Ti/SiO2/Si substrates by a sol-gel method and then crystallized by 2.45 GHz microwave irradiation in the magnetic field. The crystalline phases and microstructures as well as the electrical properties of the PZT films were investigated as a function of the annealing temperature from 550 to 750°C for 60 s. The crystallization behavior of the PZT films annealed at 650°C for different times were also investigated. X-ray diffraction and transmission electron microscopy reveal that the pyrochlore phase is formed initially but that it transforms into the perovskite phase very quickly. The ferroelectric and dielectric properties of the PZT films are correlated to the crystallization behavior. The annealing time to obtain perovskite PZT films with good electrical properties at 650°C is only 60 s, and is much shorter than that in conventional furnace annealing process. The reasons for the reduction of annealing time in the rapid microwave annealing process are also discussed.