Development of characterization of PZT thick films fabricated by an improved sol-gel method

The development of next-generation portable MEMS (microelectrical-mechanical systems) call for PZT (lead zirconate titanate oxide) film sensors and actuators with thickness in the range of 1-10 mum. The aim of this project is to fabricate and characterize PZT films with the thickness between 1 and 10 mum by an improved sol-gel method. Two techniques were applied to improve the conventional sol-gel processing: precursor concentration modulation, rapid thermal annealing. Based on the inspection of XRD spectra and SEM, the films of one, two, three, and sixteen coatings from the same sol show the correct crystalline phase. Also the structure and morphology of the synthesized film were dense and crack-free with the thickness between 1 and 10 mum. The characterization methods of the PZT films for the dynamic performance and simulation were developed. The actuation tests demonstrated the silicon cantilever (4 cm times 7 mm times 0.56 mm) could be driven linearly by the PZT film (4 mm times 4 mm times 6.5 mum) at the 1st bending mode of the specimen, 346 Hz, with the amplitude of 240 nm. According to experiments, the frequency of the PZT sensing signal was the same as the driving frequency and the signal strength was proportional to the excitation voltage. This work successfully demonstrates the feasibility of PZT thick films fabricated by the improved sol-gel method