Super-high-frequency two-port AlN contour-mode resonators for RF applications

Abstract

This paper reports on the design and experimental verification of a new class of thin-film (250 nm) superhighfrequency laterally-vibrating piezoelectric microelectromechanical (MEMS) resonators suitable for the fabrication of narrow-band MEMS filters operating at frequencies above 3 GHz. The device dimensions have been opportunely scaled both in the lateral and vertical dimensions to excite a contourextensional mode of vibration in nanofeatures of an ultra-thin (250 nm) AlN film. In this first demonstration, 2-port resonators vibrating up to 4.5 GHz have been fabricated on the same die and attained electromechanical coupling, kt^2, in excess of 1.5%. These devices are employed to synthesize the highest frequency MEMS filter (3.7 GHz) based on AlN contour-mode resonator technology ever reported. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This journal article is available at ScholarlyCommons: http://repository.upenn.edu/ese_papers/522 0885-3010/$25.00 © 2010 IEEE 38 IEEE TransacTIons on UlTrasonIcs, FErroElEcTrIcs, and FrEqUEncy conTrol, vol. 57, no. 1, JanUary 2010Abstract-This paper reports on the design and experimental verification of a new class of thin-film (250 nm) superhigh-frequency laterally-vibrating piezoelectric microelectromechanical (MEMS) resonators suitable for the fabrication of narrow-band MEMS filters operating at frequencies above 3 GHz. The device dimensions have been opportunely scaled both in the lateral and vertical dimensions to excite a contourextensional mode of vibration in nanofeatures of an ultra-thin (250 nm) AlN film. In this first demonstration, 2-port resonators vibrating up to 4.5 GHz have been fabricated on the same die and attained electromechanical coupling, k t 2 , in excess of 1.5%. These devices are employed to synthesize the highest frequency MEMS filter (3.7 GHz) based on AlN contour-mode resonator technology ever reported.

High frequency Piezoelectric Resonant Nanochannel for bio-sensing applications in liquid environment

“…In fact, the presence of water introduces a large parasitic capacitance, C p (~ 680 fF), in parallel to the device geometrical capacitance, C 0 , which, as highlighted in [9], negatively affects the k t 2 of the device (k t 2 ∝C m /C 0 ). It is possible to observe ( Table I) that, when the PRN is employed, the value of such parasitic parallel capacitance, C p , is significantly reduced (C p ~38 fF) and negligible if compared to the device capacitance, C 0 .…”

Ultra-fast and high resolution NEMS thermal detector based on a nano-air-gap piezoelectric resonant structure

“…Such high Figure The achievement of a high value of device FOM is of crucial importance for the direct connection of the ovenized MEMS resonator to a compact and low-power oscillator circuit. In fact, the primary power loss in an oscillator circuit is due to the motional resistance, R m , of the resonator, the value of which is inversely proportional to the device FOM (R m ∝1/(C 0 ⋅k t 2 ⋅Q)) [7].…”

“…By reducing the thickness of the AlN plate (i.e. implementing a nano-plate) the lateral dimensions of the device can be scaled maintaining high transduction efficiency [7]. Therefore, in order to maximize the device performance it is crucial to scale the volume of the AlN resonant nano-plate maintaining, at the same time, high quality factor and power handling.…”

“…Therefore, in order to maximize the device performance it is crucial to scale the volume of the AlN resonant nano-plate maintaining, at the same time, high quality factor and power handling. According to the aforementioned design considerations, the thickness of the AlN nano-plate resonator of this work was set to 500 nm and its lateral dimensions were properly designed in order to maintain a low value of the device equivalent electrical impedance [7]. The device was designed to operate at high frequency (~ 1 GHz), which guarantees high power handling of the mechanical structure [8].…”

Use of a single multiplexed CMOS oscillator as direct frequency read-out for an array of eight AlN Contour-Mode NEMS Resonant Sensors

“…Such high values (~ 20) of the device figure of merit, k t 2 ⋅Q, are of crucial importance for the direct connection of multiple CMR-S to a compact and low power multiplexed oscillator circuit for direct frequency read-out. In fact, the primary power loss in such oscillator circuit is due to the motional resistance, R m , of the resonator [10], whose value is inversely proportional to the device figure of merit, k t 2 ⋅Q [11,12].…”