Abstract
Utilizing silicon and silicon dioxide's opposing temperature coefficients of Young's modulus, composite resonators with zero linear temperature coefficient of frequency are fabricated and characterized. The resulting resonators have a quadratic temperature coefficient of frequency of approximately-20 ppb/°C2 and a tunable turnover temperature in the-55 °C 125 °C range. Reduction of the temperature dependence of frequency is shown in flexural-mode resonators (700 kHz1.3 MHz) and extensional-mode ring resonators (20 MHz). The linear temperature coefficient of Young's modulus of silicon dioxide is extracted from measurements to be +179 ppm/°C. The composite resonators are fabricated and packaged in a CMOS-compatible wafer-scale hermetic encapsulation process. The long-term stability of the resonators is monitored for longer than six months. Although most devices exhibit less than 2 ppm frequency drift, there is evidence of dielectric charging in the silicon dioxide.
Original language | English (US) |
---|---|
Article number | 5288574 |
Pages (from-to) | 1409-1419 |
Number of pages | 11 |
Journal | Journal of Microelectromechanical Systems |
Volume | 18 |
Issue number | 6 |
DOIs | |
State | Published - Dec 2009 |
Externally published | Yes |
Keywords
- Composite
- Resonators
- Temperature coefficient
- Temperature compensation
- Young's modulus
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering