Resonant-typed microscanners fabricated by hybrid PZT deposition process on SOI wafers

Resonant-typed microscanners based on a silicon diaphragm and actuated by PZT was designed and fabricated on purpose to improve the deformed microstructure while resonating at high frequency. In order to yield large actuating force, hybrid PZT deposition process: sol-gel method and laser ablation was developed to manufacture thick PZT films with well-crystallized perovskite phase for the applications of microscanners. In our previous study, a sol-gel derived PZT was used due to the high film quality, large deposition area and easy composition control. However, to make a thick and crack-free PZT film, several times of coating and thermal treatment is not only time consumption, but increases the risk of contamination and leads the complicated problem of thermal residual stress. In this paper, the hybrid-derived PZT film with thickness of 3 μm was prepared with simplified steps and reduced processing time. Regarding to the performance of microscanners, 1D scan motion with straight patterns and scan angle of 8±1° has been demonstrated, while resonating with 7 Vp at resonance frequency (2325 Hz). The 2D scan pattern with area of (8±1°)×(5±1°) and less deformed edged was also obtained successfully due to the improvement of the silicon-based flat mirror surface.

[1]  G. G. Stokes "J." , 1890, The New Yale Book of Quotations.