High frequency fundamental resonators and filters fabricated by batch process using chemical etching

Ishii, Osamu; Morita, Tatsuro; Saito, Toshihiro; Nakazawa, Yasutaka

doi:10.1109/freq.1995.484090

Cited by 15 publications

(4 citation statements)

References 4 publications

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“…Resonators in the ultrahigh frequency (UHF) band are in the development stage for several manufacturers. [1][2][3][4] The vibrating area of a UHF AT-cut plate, which is usually fabricated with a chemical etching process, [1][2][3][4][5] is extremely thin, and the lateral dimension of the active area is very large compared with the plate thickness. The large length-to-thickness ratio of AT-cut plates normally produces an abundance of spurious resonances which belong to the flexural (F), extensional (E), and face-shear (FS) modes around the main TS response.…”

Section: Introductionmentioning

confidence: 99%

“…However, such coupling phenomena have not been experimentally observed in fabricated UHF resonators. [1][2][3][4] To interpret this strange observation, we noticed two items: (1) Circuit theory demonstrates that, for two strongly coupled vibrations, two resonant frequencies on the real axis are combined into one frequency with increasing loss. 7) (2) An analysis assuming lossless UHF plates has found strong coupling between the TS and F or E modes.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Viscosity Loss on Coupled Vibrations of Ultrahigh Frequency AT-Cut Quartz Plates

Sekimoto

Onozaki

Goka

et al. 2006

jjap

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We numerically analyze the influence of viscosity loss in quartz on the unwanted coupling between fundamental thicknessshear (TS) and spurious modes. Classical mode-matching is used to solve the two-dimensional coupled vibrations in an ATcut quartz plate with an inverted-mesa shape. Using this technique, we calculate the loci of admittance near the main TS response as a function of the loss factor. The temperature behavior of frequency and conductance is also examined for the main TS resonance. The results reveal that, for two strongly coupled vibrations of TS and spurious modes, two resonances on the real frequency-axis are combined into one with increasing loss, although there are still two resonances in the complex frequency plane. We also find that the conductance-temperature behavior of the main TS response is more sensitive to mode coupling than the frequency-temperature behavior, and it therefore works well as a detector of mode coupling.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of Viscosity Loss on Coupled Vibrations of Ultrahigh Frequency AT-Cut Quartz Plates

Sekimoto

Onozaki

Goka

et al. 2006

jjap

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“…A higher operating frequency is obtained using a thinner substrate (quartz), because the frequency of the resonator is inversely proportional to the thickness of the membrane. Quartz has been thinned by various techniques including wet etching, 3) plasma etching 4,5) and mechanical polishing. 6) Wet etching using a buffered HF solution is a method well-adapted for mass production while plasma etching provides high precision in controlling frequency.…”

Section: Introductionmentioning

confidence: 99%

Novel Method for In Situ Monitoring of Thickness of Quartz during Wet Etching

Lee¹,

Chang

Chen

et al. 2005

Jpn. J. Appl. Phys.

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In this work, we present a novel method based on a plate wave sensor for the in situ monitoring of the thickness of quartz membranes during wet etching. Similarly to oscillators and resonators, some acoustic devices require the thickness of quartz membranes to be determined precisely. Precise control of the thickness of quartz membranes during wet etching is important, because the thickness strongly influences post processing and frequency control. Furthermore, the proposed plate wave sensor, allows the thickness of quartz membranes from a few µm to hundreds of µm to be monitored in situ, which depends on the periodicity of an interdigital transducer (IDT). In summary, the proposed method for measuring the thickness of quartz membranes in real time has a high accuracy, is simple to set up and can be mass-produced. Also described herein are the principles of the method used, the detailed process flow, the measurement set up and the simulation and experimental results. The theoretical and measured values differ by an error of less than 1 µm, implying a close correspondence.

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“…Chemical etching techniques have been extensively investigated along with ion milling to obtain thinner regions [3][4][5][6][7][8][9][10][11]. Considerable effort has been directed towards chemical etching techniques that do not leave a crystal facet roughened surface and resonators are commercially available.…”

Section: Thin Crystal Platesmentioning

confidence: 99%

Thin film resonator technology

Lakin¹

IEEE International Frequency Control Sympposium and PDA Exhibition Jointly With the 17th European Frequency and Time Forum, 200

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The thin film resonator technology has been under development for over forty years in one form or another. Although the basic approach is derived from the desire to reach higher frequencies than those readily achieved by thinning bulk crystals, there have always been competing technologies or fundamental material or processing problems that have impeded the development. Finally, a point was reached in the wireless market wherein competing technologies appeared unable to meet the demands of modern wireless applications and thin film approaches began to receive some emphasis. This paper will survey the thin film resonator technology. Every effort will be made to provide an objective analysis of the technology in relation to applications and competing technologies, and point out obstacles and promises, as known, for further technology advancement to high frequencies.

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High frequency fundamental resonators and filters fabricated by batch process using chemical etching

Cited by 15 publications

References 4 publications

Influence of Viscosity Loss on Coupled Vibrations of Ultrahigh Frequency AT-Cut Quartz Plates

Influence of Viscosity Loss on Coupled Vibrations of Ultrahigh Frequency AT-Cut Quartz Plates

Novel Method for In Situ Monitoring of Thickness of Quartz during Wet Etching

Thin film resonator technology

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