A High-Performance Dual-Cantilever High-Shock Accelerometer Single-Sided Micromachined in (111) Silicon Wafers

摘要

A single-side processed dual-cantilever high-shock accelerometer in (111) silicon wafers is proposed in this paper. The device is formed by using advanced silicon surface and bulk micromachining technologies, including deep-reactive ionic etch and lateral under-etching structural release. Because the sensor is fabricated in (111) silicon wafer and has a single-chip single-side structure, it facilitates simple post-packaging, reduced device dimension, and low cost mass production. The controllable gap distance between the bottom surface of the cantilever and the substrate can be used for restraining cross-sensitivity of orthogonal direction. The performance of the accelerometer is examined by using a free dropping hammer system. The results of the shock test show the acceleration sensitivity of 0.71 $muhbox{Vg}^{-1}$ for a 20 500 g shock acceleration under 3.3 V power supply and the resonant frequency of 79 kHz. The zero-point offset temperature drift of the sensor is 89 $hbox{ppm}/^{circ}hbox{C}$ within the temperature range of $-20 ^{circ}hbox{C}$ to 120 $^{circ}hbox{C}$. $ hfill$[2010-0048]