A High-Performance MEMS Accelerometer with an Improved TGV Process of Low Cost

Micromachines (Basel). 2022 Jul 5;13(7):1071. doi: 10.3390/mi13071071.

Abstract

High-performance MEMS accelerometers usually use a pendulum structure with a larger mass. Although the performance of the device is guaranteed, the manufacturing cost is high. This paper proposes a method of fabricating high-performance MEMS accelerometers with a TGV process, which can reduce the manufacturing cost and ensure the low-noise characteristics of the device. The TGV processing relies on laser drilling, the metal filling in the hole is based on the casting mold and CMP, and the packaging adopts the three-layer anodic bonding process. Moreover, for the first time, the casting mold process is introduced to the preparation of MEMS devices. In terms of structural design, the stopper uses distributed comb electrodes for overload displacement suppression, and the gas released by the packaging method provides excellent mechanical damping characteristics. The prepared accelerometer has an anti-overload capability of 10,000 g, the noise density is less than 0.001°/√Hz, and it has ultra-high performance in tilt measurement.

Keywords: MEMS accelerometer; TGV; comb structure; distributed stoppers.

Grants and funding

This work is supported by The Laboratory Open Fund of Beijing Smart-chip Microelectronics Technology Co., Ltd., and the Chinese National Science Foundation (Contract No. 52075519 and 61974136).