An in-plane high-sensitivity, low-noise micro-g silicon accelerometer with CMOS readout circuitry


Chae J., Kulah H. , Najafi K.

JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, cilt.13, ss.628-635, 2004 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 13 Konu: 4
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1109/jmems.2004.832653
  • Dergi Adı: JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
  • Sayfa Sayıları: ss.628-635

Özet

A high-sensitivity, low-noise in-plane (lateral) capacitive silicon microaccelerometer utilizing a combined surface and bulk micromachining technology is reported. The accelerometer utilizes a 0.5-mm-thick, 2.4 x 1.0 mm(2) proof-mass and high aspect-ratio vertical polysilicon sensing electrodes fabricated using a trench refill process. The electrodes are separated from the proof-mass by a 1.1-mum sensing gap formed using a sacrificial oxide layer. The measured device sensitivity is 5.6 pF/g. A CMOS readout circuit utilizing a switched-capacitor front-end Sigma - Delta modulator operating at 1 MHz with chopper stabilization and correlated double sampling technique, can resolve a capacitance of 10 aF over a dynamic range of 120 dB in a 1 Hz BW. The measured input referred noise floor of the accelerometer-CMOS interface circuit is 1.6mug/rootHz in atmosphere.