| This paper analyzed the electrical properties of PZT thin films,and explored the influence of Pr doping on the properties of them.The graphic processes of bottom electrode,PZT thin films and top electrode were optimized.The piezoelectric microactuators were fabricated and their vibration performances were characterized.The main research contents are shown below.（1）The influence of Pr doping on the properties of PZT films was studied.PPZT precursor solutions doped with different Pr concentrations were prepared by sol-gel method according to chemical formula Pb1.2-1.5x PrxZr0.52Ti0.48O3,in which X=0,1,2,3,4 and 5.When weighing lead acetate trihydrate drugs,the method of lead excess of 20%was adopted to solve the problem of component ratio imbalance in the film caused by lead volatilization in the subsequent heat treatment.The PZT thin film with thickness of 1μm was prepared by multiple spins and heat treatment.The process of heat treatment includes drying to remove moisture,pyrolysis to remove organic matter and high temperature to anneal crystallization.The properties of PPZT thin films were characterized,and the experimental results showed that PPZT thin films doped with Pr concentration of 2%had the best comprehensive properties,where degree of preferential orientation of（100）crystal direction was up to 81.5%.The cross-section showed the obvious dense perovskite columnar structure.The dielectric constant was the highest,reaching 1462.1,which was 10.37%higher than that of undoped PZT thin film（1324.7）.The residual polarization intensity was the largest,reaching 12.79μC/cm2,which was 63.35%higher than that of the undoped PZT thin film（7.83μC/cm2）.After 108 polarization reverses,the residual polarization strength decreased to 61.4%of the initial value,while the residual polarization strength of the undoped PZT thin film decreased to 39.5%of the initial value.In this paper,after analysis of doping modification mechanism,found that the introduction of three valence doped ions will play a dual role of donor-doping and acceptor-doping.The influence of this on the properties of PZT thin films prepared by sol-gel method mainly included two aspects:one was to change the crystal structure inside the films;the other was to change the turnover ability of internal electric domains.Through the influence of these two aspects,the properties of the films were changed.（2）The graphic technology of bottom electrode,PZT thin films and top electrode was introduced.The Pt/Ti bottom electrode and Pt top electrode were deposited by DC magnetron sputtering.The Pt/Ti bottom electrode and PZT film were graphically etched by wet corrosion.While the Pt top electrode was graphically etched by lithography and stripping.The experimental results showed that the corrosion rate of Pt in aqua aureus was about 3.33 nm/s,and that of Ti in HF was about 5 nm/s.The average corrosion rate of PZT thin films in the configured PZT corrosive liquid was about 5.26 nm/s.The lateral corrosion can be effectively reduced by means of repeated corrosion-cleaning-corrosion.（3）The piezoelectric microactuators were fabricated,whose vibration performance were characterized.A positive T-wave voltage with amplitude of 5V,10V,15V,20V and frequency of 10 kHz was applied to the vibration plates made of PPZT thin films with different Pr doping concentrations.The experimental results showed that proper Pr doping can improve the piezoelectric performance of PZT thin films.When the voltage was 20V,the amplitude of the piezoelectric microactuator made of PPZT thin film with Pr doped concentration of 2%was the highest,reaching 414.5 nm,which was 39%higher than that of the piezoelectric microactuator made of undoped PZT thin film（298.1 nm）. |
