Transduction of High-Frequency Micromechanical Resonators Using Depletion Forces in p-n Diodes

• Published in: IEEE transactions on electron devices Vol. 58; no. 8; pp. 2770 - 2776
• Main Authors: Hwang, Eugene, Bhave, S. A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Capacitance; Charge; Circuit properties; Compound structure devices; Depletion; Dielectrics; Diodes; Doping; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Force; Junctions; Micro- and nanoelectromechanical devices (mems/nems); Micromechanical resonators; Oscillators, resonators, synthetizers; p-n diode; Quality factor; quality factor (Q); radio-frequency microelectromechanical systems (RF MEMS); Resonant frequencies; Resonant frequency; Resonators; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Strain; Micromechanical resonators; radio-frequency microelectromechanical systems (RF MEMS); Diode; High Q factor; Q factor; Frequency scaling; Doped materials; p n junction; quality factor (Q); Radiofrequency; Resonance frequency; Air gap; Silicon; High frequency; p-n diode; Microelectromechanical device; Room temperature
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2011.2158103

We present in this paper the design and fabrication of a homogeneous silicon micromechanical resonator actuated using forces acting on the immobile charge in the depletion region of a symmetrically doped p-n diode. The proposed resonator combines the high quality factor Q of air-gap-transduced resonators with the frequency-scaling benefits of internal dielectrically transduced resonators. Using this transduction method, we demonstrate a thickness-longitudinal-mode micromechanical resonator with Q ~18000 at a resonant frequency of 3.72 GHz at room temperature, yielding an f · Q product of 6.69 × 10 13 Hz, which is the highest reported value for a silicon micromechanical resonator to date.