E-beam Evaporated Polysilicon for Lead Zirconate Titanate-Based Micro-Actuators

This letter reports the application of ultra-high vacuum E-beam evaporated polysilicon (UHVEEPoly) film for lead zirconate titanate (PZT)-based piezoelectric micro-electromechanical systems (MEMSs) for the first time. The UHVEEPoly film is employed as a passive structural layer in unimorph piezoelectric cantilever micro-actuators to demonstrate its applicability in PZT-based MEMS. Two sets of PZT micro-cantilever actuators have been fabricated and characterized in this letter. The first set has 4-μm-thick UHVEEPoly as a structural layer while the second set is made of 4 μm thick single crystalline silicon structural layer obtained from an active layer of a siliconon-insulator wafer. The static and dynamic behaviors of the two sets of actuators including their initial deflection profiles have been measured and compared. Results confirmed that the two sets of actuators exhibit similar characteristics, indicating the unique suitability of the UHVEEPoly films for realizing PZT-based MEMS that enables a cost effective process and formation of versatile MEMS structures.