Bulk wave resonator and manufacturing method thereof

Abstract

The invention discloses a piezoelectric bulk wave resonator and a manufacturing method thereof. The piezoelectric bulk wave resonator comprises a multilayer structure and a substrate, wherein at least one groove is arranged in the surface of the substrate, the multilayer structure covers the at least one groove, and an acoustic reflection structure of the piezoelectric bulk wave resonator is formed by at least one formed cavity; the multilayer structure is sunken to the bottom of the cavity in each cavity and is not in contact with the bottom of the cavity; or the multilayer structure is raised in a direction which is far away from the bottom of the cavity, and the raised height is greater than or equal to the predetermined raised height. According to the invention, through controlling the downwards sunken degree and the upwards raised height of the multilayer film structure in the piezoelectric bulk wave resonator, good air reflection interfaces are arranged on the upper side and the lower side of the multilayer film structure of the piezoelectric bulk wave resonator, so that a good reflection effect of bulk acoustic wave is ensured, and a value Q is 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 manufacturing method thereof. 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 bulk acoustic wave piezoelectric filter / duplexer provides superior filtering characteristics, such as low insertion loss, steep transition band, large power capacity, strong anti-electrostatic discharge (ESD) ability, etc. [0003] The high-frequency multilayer film structure piezoelectric bulk wave oscillator has ultra-low frequency temperature drift, and its advantages are: low phase noise, low power consumption and large bandwidth mod...

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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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