Static High Voltage Actuation of Piezoelectric AlN and AlScN Based Scanning Micromirrors

Piezoelectric micromirrors with aluminum nitride (AlN) and aluminum scandium nitride (Al_0.68Sc_0.32N) are presented and compared regarding their static deflection. Two chip designs with 2 × 3 mm² (Design 1) and 4 × 6 mm² (Design 2) footprint with 600 nm AlN or 2000 nm Al_0.68Sc_0.32N as piezoelectric transducer material are investigated. The chip with Design 1 and Al_0.68Sc_0.32N has a resonance frequency of 1.8 kHz and a static scan angle of 38.4° at 400 V DC was measured. Design 2 has its resonance at 2.1 kHz. The maximum static scan angle is 55.6° at 220 V DC, which is the maximum deflection measurable with the experimental setup. The static deflection per electric field is increased by a factor of 10, due to the optimization of the design and the research and development of high-performance piezoelectric transducer materials with large piezoelectric coefficient and high electrical breakthrough voltage.