Fabrication of nanoelectromechanical systems in single crystal silicon using silicon on insulator substrates and electron beam lithography

161

119

We demonstrate piezoelectrically actuated, electrically tunable nanomechanical resonators based on multilayers containing a 100-nm-thin aluminum nitride ͑AlN͒ layer. Efficient piezoelectric actuation of very high frequency fundamental flexural modes up to ϳ80 MHz is demonstrated at room temperature. Thermomechanical fluctuations of AlN cantilevers measured by optical interferometry enable calibration of the transduction responsivity and displacement sensitivities of the resonators. Measurements and analyses show that the 100 nm AlN layer employed has an excellent piezoelectric coefficient, d 31 = 2.4 pm/ V. Doubly clamped AlN beams exhibit significant frequency tuning behavior with applied dc voltage.

mentioning

confidence: 99%

Piezoelectric nanoelectromechanical resonators based on aluminum nitride thin films

Karabalin

Matheny

Feng

et al. 2009

161

119

“…Another motivation is to study the properties of those materials using NEMS. To date, NEMS have been fabricated and reported, in Si, 3 Si x N y , 4 SiC, 5 AlN, 6 and spin-on glass. 7 In this work, we report on nanomechanical resonant structures fabricated in nanocrystalline diamond.…”

mentioning

confidence: 99%

Nanomechanical resonant structures in nanocrystalline diamond

Šekarić

Parpia

Craighead

et al. 2002

183

110

We report the fabrication and the operation of nanomechanical resonant structures in nanocrystalline diamond. For this purpose, continuous diamond films as thin as 80 nm were grown using microwave plasma enhanced chemical vapor deposition. The lateral dimensions of the fabricated structures were as small as 50 nm and the measured mechanical resonant frequencies were up to 640 MHz. The mechanical quality factors were in the range of 2500-3000 at room temperature. The elastic properties of these films obtained via the resonant measurements indicate a Young's modulus close to that of single-crystal diamond.

“…The vertical motion of the surface of the shell was detected interferometrically 21 by measuring the variation of the intensity of a red HeNe laser beam reflected by the dome. Using a XY Z micropositioning system and an optical microscope, the 5 m diameter laser spot can be located at any place of interest on the shell.…”

mentioning

confidence: 99%

Shell-type micromechanical actuator and resonator

Zalalutdinov

Aubin

Reichenbach

et al. 2003

Dome-shaped radio-frequency micromechanical resonators were fabricated by utilizing the buckling of a prestressed thin polysilicon film. The enhanced rigidity of the dome structure leads to a significant increase of its resonant frequency compared to a flat plate resonator. The shell-type geometry of the structure also provides an imbedded actuation mechanism. Significant out-of plane deflections are actuated by mechanical stress introduced within the plane of the shell. We demonstrate that thermomechanical stress generated by a focused laser beam, or microfabricated resistive heater, provides an effective and fast mechanism to operate the dome as an acoustic resonator in the radio-frequency range. All-optical operation of the shell resonator and an integrated approach are discussed. © 2003 American Institute of Physics. ͓DOI: 10.1063/1.1622792͔ High-frequency microelectromechanical systems ͑MEMS͒ are widely considered as an element base for signal processing in the next generation of wireless communication devices. 1-3 Parametric amplification, 4,5 limit cycle oscillations, 6 and injection locking 7 demonstrated for MEMS oscillators allows one to build active circuits where signal processing would be implemented in the mechanical domain. However, a transduction mechanism for the effective conversion between the electrical and mechanical forms of the signal remains one of the key problems in MEMS design. The widely used capacitive drive 8 imposes restrictions related to cross talk issues and to high voltages required for actuation. Piezoelectric 9 or magnetomotive 10 actuation cannot be readily integrated because of the requirement for integrated circuit ͑IC͒-incompatible materials or high magnetic fields.In this letter, we demonstrate a design for a rf MEMS resonator based on the geometry of a shallow segment of a thin spherical shell. The finite curvature of the shell introduces an imbedded actuation mechanism by coupling the in-plane stress to the out-of-plane deflection of the shell. 11 The key feature of the shell actuation mechanism described in this letter is the local nature of the driving stress introduced at a specific point of the shell. A similar approach is employed in the design of macroscopic induced-strain actuators, 12,13 for ''smart structures'' actuated by small piezoelectric patches, surface bonded on a cylindrical shell at certain locations.In our micromechanical shell actuator, the in-plane strain is provided by stress introduced directly inside the shell layer. In our experiments we employ thermoelastic stress created by heating of the shell either by using a focused laser beam or a microfabricated heater. Using local heating, one can actuate cantilevering shell or bowl-type structures ͑shells supported at the center point͒. In the latter case, the compressive stress applied in the hoop direction close to the free edge of the shell flattens the bowl and provides a vertical component to the deflection of the periphery. The resulting motion can be complicated; thus for the configuration cons...