Monolithic Accelerometer for 3D Measurements

Abstract

Bulk micromachining low-g accelerometers for single axis measurements are today’s state of the art technology for measuring low-g range signals in automotive, medical and other applications — also referred as “human scale motion”. The latest trend in silicon micromachining is smoothening the border between bulk and surface micromachining. A combination of SOI (Silicon On Insulator) wafers and DRIE (Deep Reactive Ion Etching) as new technologies is leading to smaller and more cost efficient micromachined inertial sensors. A novel capacitive 3-axis accelerometer element is the first example of this combination by VTI Technologies. The key task was to overcome the physical limitation to measure a 3-dimensional acceleration signal with a 2-dimensional silicon element that suits to modern packaging constraints. It will be shown how the new sensor element is working and that the similarity of the manufacturing process with today’s mass produced VTI single axis accelerometer, will lead to a fast commercialization of the novel 3-axis design. Additionally the utilization of this technology platform for further projects will be sketched.