Design and Fabrication Method of In-Plane Stretch Resonator with Annular Detection Electrode

Abstract

The invention discloses an in-plane telescopic resonator of an annular detection electrode and a preparation method thereof. The resonator includes: a lower electrode buffer layer, a lower electrode layer, a piezoelectric layer, an insulating protection layer and an upper electrode layer grown sequentially on the substrate, and the main structure of the in-plane stretchable resonator includes a coupling beam connecting The circular plate drive unit and the detection unit, the drive unit includes a circular lower electrode, a piezoelectric film layer and a circular upper electrode layer covering it from the bottom, and the detection unit includes a ring-shaped lower electrode layer, a piezoelectric film layer from the bottom And the ring-shaped upper electrode layer covered above, the coupling beam between the driving unit and the detection unit has no upper electrode layer, the overall outer side of the main structure is fixedly connected to the substrate through the two ends of the anchor point; the lower part of the main structure The substrate is etched on the back to form a floating structure.

Description

technical field [0001] The invention relates to a circular in-plane telescopic resonator structure with ring-shaped detection electrodes, which is a novel in-plane telescopic resonator structure applied in the field of MEMS resonators. Background technique [0002] Compared with traditional quartz crystal resonators or general silicon-based resonators, the in-plane stretch mode resonator has a resonant frequency up to GHz and a smaller dynamic impedance. Compared with thin-film bulk acoustic resonators, which are also applied to high frequencies, but whose resonant frequency is determined by the thickness of the film, CMRs can be resonant with different frequencies by changing the shape and size of the chip because the resonant frequency can be determined by the in-plane size. The device unit provides the possibility to realize single-chip wireless communication. Therefore, in-plane stretch resonators have broad application prospects in communication systems. [0003] The ...

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Problems solved by technology

[0003] The in-plane stretchable resonator mainly adopts a sandwich suspension structure (upper electrode-piezoelectric layer-lower electrode), but simply preparing the upper electrode, piezoelectric layer, and lower electrode layer into exactly the same shape will not only make the overlapping parts of the upper and lower electrodes The capacitance seriously affects the transmission and detection of high-frequency signals, and the detection electrodes are all covered in the piezoelectric layer, which will also introduce interference from stray modal signals

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