Surface micromachined AlN thin film 2 GHz resonator for CMOS integration

Hara, Motoaki; Kuypers, Jan H.; Abe, Takashi; Esashi, Masayoshi

doi:10.1016/j.sna.2004.06.014

Cited by 44 publications

(23 citation statements)

References 11 publications

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“…In particular, AlN as a piezoelectric material has good dielectric properties, such as low losses, high ultrasonic velocity, and electromechanical coupling coefficient [4][5]. Polycrystalline c-axis textured AlN films can be deposited by reactive radio frequency (RF) magnetron sputtering with a pure Al target in a N 2 /Ar atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Influence of substrate metals on the crystal growth of AlN films

Xiong

et al. 2010

Int J Miner Metall Mater

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AlN films were deposited by reactive radio frequency (RF) sputtering on various bottom electrodes, such as Al, Ti, Mo, Au/Ti, and Pt/Ti. The effects of substrate metals on the orientation of AlN thin films were investigated. The results of X-ray diffraction, atomic force microscopy, and field emission scanning electron microscopy show that the orientation of AlN films depends on the kinds of substrate metals evidently. The differences of AlN films deposited on various metal electrodes are attributed to the differences in lattice mismatch and thermal expansion coefficient between the AlN material and substrate metals. The AlN film deposited on the Pt/Ti electrode reveals highly the c-axis orientation with well-textured columnar structure. The positive role of the Pt/Ti electrode in achieving the high-quality AlN films and high-performance film bulk acoustic resonator (FBAR) may be attributed to the smaller lattice mismatch as well as the similarity of thermal expansion coefficient between the deposited AlN material and the Pt/Ti electrode substrate.

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Section: Introductionmentioning

confidence: 99%

Influence of substrate metals on the crystal growth of AlN films

Xiong

et al. 2010

Int J Miner Metall Mater

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“…Although the material constants for AlN are taken from thin films [15] the TCF observed for FBAR devices (8), which is much simpler in nature than Lamb wave devices, does not agree well with the theoretical predictions [14]. I.e.…”

Section: A Materials Data Long-term Stability and Repeatabilitymentioning

confidence: 87%

“…At the same time the fabrication process is identical to thin film bulk acoustic resonators (FBAR), which have shown to be CMOS compatible [8] [9]. This paper focuses on the design issues and advantages of using thermally compensated Lamb wave resonators for thin AlN plates and the possibility of compensating a wide range of frequencies using only two thin film depositions.…”

Section: Introductionmentioning

confidence: 99%

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Intrinsic temperature compensation of aluminum nitride Lamb wave resonators for multiple-frequency references

Kuypers

Lin

Vigevani

et al. 2008

2008 IEEE International Frequency Control Symposium

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In this paper we present the temperature compensation of aluminum nitride (AlN) Lamb wave resonators for a future application to XOs and TCXOs for a frequency ranging from 100 MHz to 1000 MHz. The temperature coefficient of frequency (TCF) for the lowest symmetric Lamb wave mode S 0 for AlN plates with h/λ < 0.3 is found to be around -30 ppm/K. A zero TCF resonator is obtained by adding a compensating silicon dioxide layer. The low dispersion of the phase velocity for the S 0 -mode propagating in thin AlN plates reduces not only the fabrication tolerances towards thickness variations of the AlN layer, but also enables resonators operating over a wide frequency range, i.e. from 100 MHz to 1000 MHz, based on two absolute film thicknesses for AlN and SiO 2 achieving near zero TCF over the entire frequency range. The acoustic properties and different layer configurations of zero TCF Lamb wave devices are discussed in detail.

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“…Metal electrodes tend to exhibit high levels of thermoelastic damping and can reduce the overall Q of a resonator by an order of magnitude of more [8], [9]. Consequently, relatively low Q's have been reported in several 1057-7157/$25.00 © 2007 IEEE previous efforts at demonstrating piezoelectric microresonators [10], [11].…”

Section: Introductionmentioning

confidence: 99%

Piezoelectric Disk Resonators Based on Epitaxial AlGaAs Films

Deng

Kumar

et al. 2007

J. Microelectromech. Syst.

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A new design for anisotropic piezoelectric disk resonators is demonstrated using single-crystal Al 0 3 Ga 0 7 As films. The shape of the disk resonator is based on the velocity propagation profile of the elastic wave in the plane of the piezoelectric film, with lateral dimensions scaled to the half wavelength of the desired resonance frequency. The resonators are designed with supports which emulate free-free boundary conditions. Prototype resonators are fabricated using a three-layer Al 0 3 Ga 0 7 As heterostructure containing silicon-doped electrodes and an undoped piezoelectric Al 0 3 Ga 0 7 As layer. Quality factors as high as 11 200 are measured in air for a 23.25 MHz fundamental resonant mode, with a corresponding motional resistance of 1.67 k. A finite-element model for the resonator design is also described. Simulation results agree well with both theoretical calculations and experimental data.[ 2006-0008]Index Terms-AlGaAs, piezoelectric resonator, radio-frequency (RF) microelectromechanical systems (MEMS).

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Surface micromachined AlN thin film 2 GHz resonator for CMOS integration

Cited by 44 publications

References 11 publications

Influence of substrate metals on the crystal growth of AlN films

Influence of substrate metals on the crystal growth of AlN films

Intrinsic temperature compensation of aluminum nitride Lamb wave resonators for multiple-frequency references

Piezoelectric Disk Resonators Based on Epitaxial AlGaAs Films

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