Development of Six-Degree-of-Freedom Inertial Sensors With an 8-in Advanced MEMS Fabrication Platform

This paper presents the development of an 8-in six-degree-of-freedom (DOF) inertial sensor based on an advanced capacitive inertial sensor fabrication platform. The platform integrates three-axis gyroscopes and three-axis accelerometers on the same chip. The fabricated sensors are vacuum packaged at the wafer level with a polysilicon-based through-silicon interposer (TSI) using the aluminum-germanium eutectic bonding approach. Waferlevel measurement results indicate that a fabrication yield of greater than 92% and a vacuum level of ~100 mtorr have been achieved. The fabricated inertial sensors and the customized application-specific integrated circuits are encapsulated in a 5 mm × 5 mm × 1.3 mm quad-flat no-leads package using the plastic molding technology. The system level characterization of the developed six-DOF inertial sensors have been implemented. Several reliability tests conducted according to the relevant JEDEC standards prove that the packaged sensors are highly reliable and robust for a wide range of operating environments.