A post-CMOS micromachined lateral accelerometer

Abstract

In a post-complementary metal-oxide-semiconductor (CMOS) micromachining technology, the process flow enables the integration of micromechanical structures with conventional CMOS circuits which are low-cost and readily available. This paper presents a lateral capacitive sensing accelerometer fabricated in the post-CMOS process. Design advantages include electrically isolated multimetal routing on microstructures to create full-bridge capacitive sensors, and integration to increase transducer sensitivity by minimizing parasitic capacitance. In a size of 350 /spl mu/m by 500 /spl mu/m, this accelerometer has a 1 mG//spl radic/(Hz) resolution and a linear range of at least /spl plusmn/13 G. The fundamental limitations of mechanical and electronic noise for acceleration sensing are addressed.