Vertical capacitive SiBARs

This work introduces high frequency, vertical silicon bulk acoustic resonators (SiBAR). A combination of the new resonator structures with much larger transduction area and the HARPSS fabrication process is used to demonstrate high frequency capacitive resonators with significantly lower impedances compared to the previous capacitive resonators. Impedances as low as a few kilo-Ohms and quality factors in the range of 20,000 to 50,000 in the VHF range have been achieved for the first thickness mode of the fabricated resonators. Resonant frequencies as high as 983MHz are demonstrated for the third thickness modes of the capacitive SiBARs.

[1]  Sheng-Shian Li,et al.  Micromechanical "hollow-disk" ring resonators , 2004, 17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest.

[2]  J. Bokor,et al.  Atomic Force Microscopy characterization of electromechanical properties of RF acoustic bulk wave resonators , 2004, 17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest.

[3]  F. Ayazi,et al.  VHF single crystal silicon capacitive elliptic bulk-mode disk resonators-part II: implementation and characterization , 2004, Journal of Microelectromechanical Systems.

[4]  F. Ayazi,et al.  SOI-based HF and VHF single-crystal silicon resonators with SUB-100 nanometer vertical capacitive gaps , 2003, TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664).

[5]  F. Ayazi,et al.  High frequency capacitive micromechanical resonators with reduced motional resistance using the HARPSS technology , 2004, Digest of Papers. 2004 Topical Meeting onSilicon Monolithic Integrated Circuits in RF Systems, 2004..

[6]  John D. Larson,et al.  Power handling and temperature coefficient studies in FBAR duplexers for the 1900 MHz PCS band , 2000, 2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121).

[7]  John D. Larson,et al.  Thin film bulk wave acoustic resonators (FBAR) for wireless applications , 2001, 2001 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.01CH37263).

[8]  J. Tsutsumi,et al.  Ultra-miniaturized and high performance PCS SAW duplexer with steep cut-off filters , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).