Epitaxially encapsulated resonant accelerometer with an on-chip micro-oven

This paper reports, for the first time, on-chip ovenization of an epitaxially encapsulated resonant accelerometer to improve the stability of scale factor and bias. A double-ended tuning fork (DETF) resonator that shares the anchor with the sensing resonators is used to measure the device temperature. The measured temperature is maintained at a fixed set point using an on-chip silicon heater defined in the encapsulation layer. Preliminary results show significant improvement beyond the device's intrinsic passive temperature compensation. Over the temperature range from −20°C to 80°C, the 0g bias error is reduced by a factor of three, and the scale factor stability is improved by over an order of magnitude.