Performance comparison of integrated z-axis frame microgyroscopes

This paper describes two different integrated surface-micromachined z-axis frame gyros fabricated side by side on a single chip for performance comparison. Frame microgyros; using an 'Inside Sense Outside Drive (ISOD)' and an 'Inside Drive Outside Sense (IDOS)' suspension designs were fabricated in the Analog Devices Modular-MEMS process using 6 /spl mu/m thick polysilicon as the structural material co-fabricated with a 0.8 /spl mu/m CMOS process. Initial characterization of these gyros suggest the ISOD frame gyro has a factor of three lower quadrature and Coriolis offset and a factor of five lower noise floor (limited by electronic noise) in comparison with the IDOS frame gyro. The surface-micromachined z-axis ISOD frame gyro exhibited a noise floor of 0.01/spl deg//s//spl radic/Hz and a scale factor of 1.5 mV//spl deg//s at 70 milli-Torr pressure.