Deposition of PZT thin films by pulsed laser ablation for MEMS application

Deposition of PZT with UV laser ablation for realization of thin film sensors and actuators. Deposition rate of more than 3 micron/hour was attained by pulsed KrF excimer laser deposition, which is fairly better than those obtained by other methods like sputtering and sol-gel process. Perovskite phase was obtained at room temperature deposition with fast atom beam (FAB) treatment and annealing. Cohesion between substrate and PZT were also improved with FAB irradiation during deposition. Smart MEMS is now a subject of interest in the field of micro optical device, micro pump, AFM cantilever devices etc. It can be fabricated by deposition of PZT thin films and micromachining. The reported thin films have been mostly prepared by sol-gel process and sputtering process. However PZT film of more than 1 micron thickness is difficult to obtain because of low deposition rate for sputtering process. However PZT film of more than 1 micron thickness is difficult to obtain because of low deposition rate for sputtering and accumulated thermal stress in sol-gel process. This is the reason why we applied excimer laser ablation for thin film deposition. Deposition was done in an ultra high vacuum chamber with 6 targets and a 3 inches wafer size substrate which can be heated up to 1273 K. Targets and substrate were rotated during deposition for improvement of thickness uniformity of deposited layer. Effects of deposition parameters such as LASER wave length, power density and radiation conditions were investigated on deposition rate and film properties. Effect of annealing was also investigated with XRD analysis. Relative dielectric constant is measured for thin films, and the micromachined cantilever beams were fabricated for measuring the deflection of the beams.