DRIE and Bonding Assisted Low Cost MEMS Processing of In-plane HAR Inertial Sensors

We present a simple, flexible and low cost MEMS fabrication process, developed using deep reactive ion etching (DRIE) and wafer bonding technologies, for manufacturing in-plane high aspect ratio (HAR) inertial sensors. Among examples, the design and fabrication results of a two axis inertial device are presented. Fabricated device thickness ranged up to 140 mum and a HAR of 28 was obtained. Compared to the existing approaches reported in literature, the salient features of the presented process are: single-sided single-wafer processing using just two lithographic masks, capability to fabricate standalone MEMS as well as CMOS compatible MEMS post-processing via process variations, the use of plasma etching for wafer thinning that facilitates stictionless dry-release of MEMS, and its suitability for batch processing.