Tunable preset cavity type silicon on insulator (SOI) substrate film body acoustic resonator and manufacturing method thereof

Abstract

The invention discloses a tunable preset cavity type silicon on insulator (SOI) substrate film body acoustic resonator and a manufacturing method thereof, and relates to a frequency tunable resonator and the manufacturing method thereof. The tunable preset cavity type SOI substrate film body acoustic resonator comprises an SOI substrate with a cavity and a piezoelectric thin film transducer arranged on the substrate; the resonator comprises a piezoelectric film, a bottom electrode and a top electrode; one side of the bottom electrode close to the preset cavity is provided with an SOI tuning layer, and the thickness of the SOI tuning layer is controlled by controlling corrosion time; the surface of a substrate silicon chip in the SOI substrate with the cavity is provided with a groove; andthe substrate silicon chip and a top layer silicon form a closed cavity structure after being bonded. As the preset cavity structure is adopted, the tunable preset cavity type SOI substrate film bodyacoustic resonator has no sacrificial layer, so a chemically mechanical polishing technology and a sacrificial layer releasing technology which are adopted when the sacrificial layer is processed in a foreign patent and a product thereof are not required; meanwhile, the tunable preset cavity type SOI substrate film body acoustic resonator integrates the advantages of small source and drain parasitic capacitance and lower voltage, low power consumption and the like of the SOI material. The tunable preset cavity type SOI substrate film body acoustic resonator can be compatible with an integrated circuit (IC), and is easy to integrate, simple in technology and suitable for mass production.

Description

technical field [0001] The invention relates to a thin-film bulk acoustic resonator and a manufacturing method, in particular to a frequency-tunable thin-film bulk acoustic resonator and a manufacturing method. Background technique [0002] Film Bulk Acoustic Resonator (FBAF) is a device that uses acoustic resonance to achieve electrical frequency selection. The common structure of FBAF is composed of several Film Bulk Acoustic Resonator (FBAR) units that are electrically cascaded. The basic working principle of FBAR is: when an electrical signal is loaded on the FBAR, the piezoelectric film in the device converts the electrical signal into an acoustic signal through the inverse piezoelectric effect, and the specific acoustic structure of the device presents selectivity to acoustic signals of different frequencies , to achieve the function of frequency regulation. [0003] The rapid development of wireless communication technology (such as mobile communication, wireless sen...

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Problems solved by technology

However, due to the very small resonator size, traditional laser trimming techniques are not a feasible solution

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