The on-chip temperature compensation and temperature control research for the silicon micro-gyroscope

Abstract

In this paper, the on-chip temperature compensation and temperature control research for the silicon micro-gyroscope are presented. The proposed micro-gyroscope architecture which integrates an on-chip temperature sensor and a serpentine micro-heater achieves the on-chip temperature compensation and the on-chip temperature control of the micro-gyroscope. We first analyze the thermodynamic steady-state temperature distribution and transient temperature response of micro-gyroscope structure. Then we simulate the temperature response of the micro-gyroscope structure by Ansys software. The Deep Dry Silicon on Glass process and wet etching process are combined for fabrication of the integrated micro-gyroscope structure. The signal measurement and control circuit based on the FPGA platform are implemented. The temperature coefficients of zero bias and scale factor are compensated with the integrated temperature sensor. Taking advantage of the drive mode resonant frequency as the temperature sensor, a high precision on-chip temperature control of micro-gyroscope is realized simultaneously. The on-chip temperature compensation and temperature control experiment of micro-gyroscope prototype is tested. Experimental results indicate that the temperature coefficients of the scale factor and zero bias decrease by 3.95 times and 3.49 times separately by on-chip temperature compensation, which optimizes significantly the temperature characteristics of the micro-gyroscope prototype. The control accuracy of drive-mode frequency reaches to 3.57 × 10?4 Hz (that is 0.123 ppm and the calculated temperature accuracy of 0.0067 °C) from 0 to 40 °C by the on-chip temperature control, which demonstrates an achievement of the precision on-chip temperature control for the micro-gyroscope.