Film bulk acoustic wave resonator prepared by employing ultrathin piezoelectric single crystal

Abstract

The invention provides a film bulk acoustic wave resonator prepared by employing ultrathin piezoelectric single crystals. The resonator comprises a high-resistance substrate with a ground chamber, and a sandwich active structure formed by clamping piezoelectrics through an upper metal electrode and a lower metal electrode. The sandwich active structure is arranged at the upper end of the high-resistance substrate. The piezoelectrics are ultrathin piezoelectric single crystals. A plurality of support posts are arranged in the ground chamber. The piezoelectric single crystals applied to the ultrathin piezoelectric single crystals are all practical piezoelectric single crystals, such as quartz, lithium tantalite, lithium tetraborate, bismuth germanate, bismuth silicate, lanthanum gallium silicate series, aluminium orthophosphate and potassium niobate. The high-resistance substrate is made of general substrate materials such as silicon, quartz, silicon carbide, aluminium oxide, sapphire and diamond in the microelectronic technology. The resonator has the advantages that the crystal completeness of the ultrathin piezoelectric single crystals is not damaged, and the ultrathin piezoelectric single crystals are perfect single crystals; the crystals and crystal orientation can be freely selected, and therefore the performance of the device is optimized; and the prospect of the production technology of the ultrathin piezoelectric single crystals is bright.

Description

technical field [0001] The invention relates to the technical field of radio frequency filters, in particular to a film bulk acoustic wave resonator made of an ultra-thin piezoelectric single crystal. Background technique [0002] Quartz crystal oscillator element is a bulk acoustic wave element based on the piezoelectric / inverse piezoelectric characteristics of quartz crystal, which is widely used in circuit frequency sources. Since the resonant frequency of the quartz crystal oscillator is inversely proportional to the thickness of the quartz crystal, its current resonant frequency is only tens of megahertz at the highest, which cannot meet the rapid extension of the modern radio spectrum. [0003] Using planar metal interdigital transducers and metal reflective grating arrays on piezoelectric substrates to excite and receive surface acoustic waves, the structure that increases the resonance frequency is converted from thinning the thickness to improving the resolution of ...

AI Technical Summary

Problems solved by technology

[0014] 3. The technical difficulty of single crystal ultra-thin sheet is not high

[0018] The characteristics of the slicing method are: it is easy to produce ultra-thin wafers with a thickness of tens of nanometers to several microns, but ion implantation will greatly damage the integrity of the crystal structure, and the characteristics of single crystals will be significantly affected

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