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

**Chris Stoeckel 1,2,\*, Katja Meinel <sup>2</sup> , Marcel Melzer <sup>2</sup> , Agne Žukauskait ˙ e˙ 3 , Sven Zimmermann 1,2 , Roman Forke <sup>1</sup> , Karla Hiller 1,2 and Harald Kuhn 1,2**


**Abstract:** Piezoelectric micromirrors with aluminum nitride (AlN) and aluminum scandium nitride (Al0.68Sc0.32N) are presented and compared regarding their static deflection. Two chip designs with <sup>2</sup> <sup>×</sup> 3 mm<sup>2</sup> (Design 1) and 4 <sup>×</sup> 6 mm<sup>2</sup> (Design 2) footprint with 600 nm AlN or 2000 nm Al0.68Sc0.32N as piezoelectric transducer material are investigated. The chip with Design 1 and Al0.68Sc0.32N 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.

**Keywords:** AlN; AlScN; aluminum nitride; aluminum scandium nitride; micromirror; microscanner; piezoelectric
