Study On PZT Thin Film And Tip Preparation Process Technology Of Piezoelectric Micro-Cantilever Probe

The atomic force microscope (AFM) with piezoelectric cantilever is a good alternative to conventional AFM because the cantilever itself is not only the deflection sensor but also the actuation. We designed a novel piezoelectric micro-cantilever probe, due to there are some problems in the fabrication process, a number of solutions were made in this paper, which included the preparation technology of PZT thin film and some specific process improvements, the frequency of piezoelectric micro-cantilever probe was tested.PZT thin films were prepared on the Pt/Ti/SiO2/Si substrate by sol-gel method, which were prepared by different annealing temperature (500℃,600℃,700℃), different thickness (4 layers,6 layers,8 layers), and the substrate was annealed or not. XRD technique was applied to analysis the PZT thin films structure. Stoney formula was applied to count the residual stress of PZT thin films. The result showed that PZT thin films had perovskite phase under different temperatures, the peaks of PZT thin films were sharpest at 600℃which indicates the films had best perovskite structure, while PZT thin films were annealed at 700℃, PbO impurity peak was appeared. PZT thin films with different thickness had little change in the microstructure of thin films after the same annealing temperature. Residual stress of Pt films was changed from tensile stress to compressive stress after annealed. PZT thin films were gained different residual stresses under different parameters. The PZT piezoelectric thin films were under tensile stress on annealed substrate, while the PZT piezoelectric thin films were under compressive stress on un-annealed substrate.600℃was the best annealing temperature for PZT thin filmsBased on the previous fabrication technology of PZT piezoelectric micro-cantilever probe, KOH and CH3CH2OH solution were applied to get sharp tips, PZT piezoeletric thin films and PZT passivation thin films were etched respectively. The first resonance frequency of pizoelectric micro-cantilever probe was 43.78 kHz when the size of probe was 450μm×70μm×10μm.