Intrinsic temperature compensation of highly resistive high-Q silicon microresonators via charge carrier depletion

We report on a novel temperature compensation technique that exploits the dependence of TCF on the free charge carriers in silicon bulk acoustic resonators (SiBARs). The free charge carriers are considerably minimized by creating single and multiple pn-junction based depletion regions in the body of the resonator. The TCF of a highly resistive (>1000 Ω-cm) conventional rectangular SiBAR has been reduced from −32 ppm/°C to −3 ppm/°C. We previously exploited the dependence of TCF on silicon resonator geometry for TCF compensation. However, at large charge carrier depletion levels achieved in this work, the TCF is found to become independent of silicon resonator geometry.

[1]  Effect of Holes on the Elastic Constant C′ of Degenerate p‐Type Si , 1965 .

[2]  A.M. Ionescu,et al.  Self-sustained low power oscillator based on vibrating body field effect transistor , 2009, 2009 IEEE International Electron Devices Meeting (IEDM).

[3]  Analysis of highly doping with boron from spin-on diffusing source , 2005 .

[4]  F. Ayazi,et al.  Temperature compensation of silicon micromechanical resonators via degenerate doping , 2009, 2009 IEEE International Electron Devices Meeting (IEDM).

[5]  T.W. Kenny,et al.  Real-Time Temperature Compensation of MEMS Oscillators Using an Integrated Micro-Oven and a Phase-Locked Loop , 2010, Journal of Microelectromechanical Systems.

[6]  F. Ayazi,et al.  High aspect-ratio combined poly and single-crystal silicon (HARPSS) MEMS technology , 2000, Journal of Microelectromechanical Systems.

[7]  Norman G. Einspruch,et al.  Effect of Doping on the Elastic Constants of Silicon , 1963 .

[8]  S. Bhave,et al.  The resonant body transistor. , 2010, Nano letters.

[9]  M. Agarwal,et al.  Thermal Isolation of Encapsulated MEMS Resonators , 2008, Journal of Microelectromechanical Systems.

[10]  Clark T. C. Nguyen.  MEMS for frequency control , 2009, 2009 IEEE International Frequency Control Symposium Joint with the 22nd European Frequency and Time forum.

[11]  D. Elata,et al.  Model and Observations of Dielectric Charge in Thermally Oxidized Silicon Resonators , 2010, Journal of Microelectromechanical Systems.

[12]  Farrokh Ayazi,et al.  MEMS for integrated timing and spectral processing , 2009, 2009 IEEE Custom Integrated Circuits Conference.

[13]  Wan-Thai Hsu,et al.  Stiffness-compensated temperature-insensitive micromechanical resonators , 2002, Technical Digest. MEMS 2002 IEEE International Conference. Fifteenth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.02CH37266).

[14]  Farrokh Ayazi,et al.  Low-Impedance VHF and UHF Capacitive Silicon Bulk Acoustic-Wave Resonators—Part II: Measurement and Characterization , 2007, IEEE Transactions on Electron Devices.

[15]  G. Casinovi,et al.  A 145MHz low phase-noise capacitive silicon micromechanical oscillator , 2008, 2008 IEEE International Electron Devices Meeting.

[16]  F. Ayazi,et al.  Effect of phonon interactions on limiting the f.Q product of micromechanical resonators , 2009, TRANSDUCERS 2009 - 2009 International Solid-State Sensors, Actuators and Microsystems Conference.

[17]  F. Ayazi,et al.  Temperature-Stable High-Q AlN-on-Silicon Resonators with Embedded Array of Oxide Pillars , 2010 .

[18]  F. Ayazi,et al.  Electrically coupled MEMS bandpass filters: Part II. Without coupling element , 2005 .

[19]  Farrokh Ayazi,et al.  Electronically Temperature Compensated Silicon Bulk Acoustic Resonator Reference Oscillators , 2007, IEEE Journal of Solid-State Circuits.

[20]  Kenneth Meade Lakin,et al.  Low‐temperature coefficient bulk acoustic wave composite resonators , 1982 .

[21]  F. Ayazi,et al.  Electrically coupled MEMS bandpass filters , 2005 .

[22]  G. Casinovi,et al.  Passive TCF compensation in high Q silicon micromechanical resonators , 2010, 2010 IEEE 23rd International Conference on Micro Electro Mechanical Systems (MEMS).