UHF quartz MEMS oscillators for dynamics-based system enhancements

Processes for fabricating full wafers of UHF quartz MEMS oscillators bonded to Si have been developed at HRL over the past several years. These devices have shown state-of-the-art noise and stability along with extremely small vacuum packaged die size of less than 3 mm. An interesting by-product of the high frequency, small size, and wafer-scale fabrication of these devices is that several novel dynamics-based enhancements can be considered. These include the use of nonlinear dynamics for reducing oscillator phase noise at CMOS capable voltages and co-integration with more complex structures for sensing vibration and serving as a local timing reference for reducing thermally-induced sensor drifts. Several of these novel concepts made possible by wafer-scale MEMS-based processing will be reviewed.