A copper CMOS-MEMS Z-axis gyroscope

Abstract

This paper reports the first thin film Z-axis gyroscope fabricated in a copper CMOS-MEMS process. It works at an ambient pressure of 1 atm and does not depend on Q enhancement. The sensor is integrated with the conditioning circuits in a commercial low-k digital copper CMOS process. The benefit of the copper CMOS-MEMS process includes high mass density and low stress. The device was fabricated in the UMC 0.18 /spl mu/m six copper layer CMOS process with dimensions of 410 /spl mu/m by 330 /spl mu/m. It consists of an outer rigid vibrating frame and an inner accelerometer to detect the Coriolis force. Measured driving mode resonant frequency is 8.8 kHz, the sensitivity is 0.8 gV//spl deg//sec and the noise floor is 0.5/spl deg//sec//spl radic/(Hz).