Silicon micro-accelerometer with rug resolution, high linearity and large frequency bandwidth fabricated with two mask bulk process

This paper presents a new kind of laterally capacity sensed accelerometer f abricated with silicon/glass anodic bonding and the inductively coupled pla sma (ICP) high aspect ratio etching. The fabrication technology only needs two masks and it does not need aligning bonding technology. The process yie ld can be higher than 90% even after package. The accelerometer fabricated with this technology shows a sensitivity of 1.85 V/g (0.6 Vp-p), a linear c oefficient of 99.9954% (-1 x g to +1 x g), a linear frequency bandwidth of 800 Hz and a - 3 dB frequency bandwidth of 1.45 KHz for open-loop applicati on. The accelerometer has a noise floor of 0.33 mg at 1.6 Hz. The accelerom eter can also at least afford 4500 g shock acceleration of 0.2 ms duration. The micro-accelerometer fabricated with this technology may be suitable fo r batch fabrication. (C) 1999 Elsevier Science S.A. All rights reserved.