AlScN Piezoelectric MEMS Mirrors with Large Field of View for LiDAR Application

Yichen Liu; Lihao Wang; Yongquan Su; Yuyao Zhang; Yang Wang; Zhenyu Wu

doi:10.3390/mi13091550

AlScN Piezoelectric MEMS Mirrors with Large Field of View for LiDAR Application

Micromachines (Basel). 2022 Sep 18;13(9):1550. doi: 10.3390/mi13091550.

Authors

Yichen Liu¹, Lihao Wang¹, Yongquan Su^{1

2}, Yuyao Zhang^{2

3}, Yang Wang^{1

4}, Zhenyu Wu^{1

2

3

4}

Affiliations

¹ State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
² School of Microelectronics, Shanghai University, Shanghai 200444, China.
³ Shanghai Industrial Technology Research Institute, Shanghai 201800, China.
⁴ University of Chinese Academy of Sciences, Beijing 100049, China.

Abstract

This paper presents AlScN piezoelectric two-axis MEMS mirrors with gimbal-less and gimbaled designs fabricated in a CMOS-compatible manner. Integrated piezoelectric sensors provided feedback signals of the actual mirror positions. The mirror with a diameter of 1.5 mm possessed adjustable optical tilt angles of up to 22.6° @ 30 V, with a high resonance frequency of about 8.2 kHz, while the 3 mm mirror reached 48.5° @ 41 V. The mirror with the gimbaled structure exhibited an excellent field of view and good mechanical decoupling. Additionally, a significant improvement in mirror scanning performance was observed in a vacuum (4 Pa), proving that the optical field of view was magnified by more than a factor of 10.

Keywords: AlScN; LiDAR; Lissajous scanning; MEMS mirror; mechanical coupling; piezoelectric.

Abstract

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