Bulk wave resonator and manufacturing method thereof

Abstract

The invention discloses a piezoelectric bulk wave resonator and a manufacturing method thereof, wherein the piezoelectric bulk wave resonator comprises: a multilayer structure; a substrate, the surface of the substrate has at least one groove, and the multilayer structure covers at least a groove through which at least one cavity is formed to constitute the acoustic reflection structure of the piezoelectric bulk wave resonator; wherein, in each cavity, the multilayer structure is depressed toward the bottom of the cavity and does not contact the bottom of the cavity contact; or, the multilayer structure protrudes away from the bottom of the cavity, and the height of the protrusion is greater than or equal to a predetermined height of the protrusion. The present invention ensures that the upper and lower sides of the multilayer film structure of the piezoelectric bulk wave resonator have good air reflection interfaces by controlling the degree of downward depression and the height of the upper protrusion of the multilayer film structure in the piezoelectric bulk wave resonator, In this way, good bulk acoustic wave reflection effect is ensured, and the Q value is kept at a high level.

Description

technical field [0001] The present invention relates to the field of semiconductors, and in particular, to a piezoelectric bulk wave resonator and a method of manufacturing the same. Background technique [0002] The multilayer piezoelectric bulk wave resonator made by using the longitudinal resonance of the piezoelectric multilayer structure in the thickness direction has become a surface acoustic wave device and a quartz crystal resonator in mobile phone communication and high-speed serial data applications. a viable alternative. RF front-end BAW piezoelectric filters / duplexers offer superior filtering characteristics such as low insertion loss, steep transition band, large power handling, strong anti-electrostatic discharge (ESD) capability, and more. [0003] The piezoelectric bulk wave oscillator of high frequency multilayer film structure has ultra-low frequency temperature drift, and its advantages are: low phase noise, low power consumption and large bandwidth modul...

AI Technical Summary

Problems solved by technology

[0015] Aiming at the problem in the related art that the deformation degree of the multilayer film structure of the piezoelectric bulk wave resonator is too large, resulting in a decrease in the Q value of the piezoelectric bulk wave resonator, the present invention proposes a piezoelectric bulk wave resonator and a manufacturing method thereof , can control the degree of deformation of the multilayer film structure of the piezoelectric bulk wave resonator, thereby ensuring a good bulk acoustic wave reflection effect and keeping the Q value at a high level

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