A Bulk-Micromachined Fully Differential MEMS Accelerometer With Split Interdigitated Fingers

Aydin O., Akın T.

IEEE SENSORS JOURNAL, vol.13, pp.2914-2921, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 13
  • Publication Date: 2013
  • Doi Number: 10.1109/jsen.2013.2264667
  • Journal Name: IEEE SENSORS JOURNAL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2914-2921
  • Keywords: Accelerometer, bulk-micromachining, fully-differential detection, split interdigitated fingers
  • Middle East Technical University Affiliated: Yes

Abstract

This paper proposes a novel bulk-micromachined MEMS accelerometer employing split interdigitated sense fingers that provide a fully differential signal interface, where the accelerometer can be fabricated by a modified silicon-on-glass process using a silicon-on-insulator (SOI) wafer. The accelerometer combines the feasibility of fabricating large mass and high aspect ratio structures using bulk-micromachining together with the highly sensitive split interdigitated sense finger triplets that are connected with multilayer metal interconnects on an SOI-glass bonded wafer. The fabricated accelerometer is packaged for system level tests with a fourth-order Sigma-Delta readout circuitry to evaluate its performance. The measurement results show that the accelerometer achieves a bias instability of 50 mu g and a velocity random walk of 11.5 mu g/root Hz. The accelerometer operates in a range of +/- 5 g with a nonlinearity of 1140 ppm