Body wave resonator and processing method thereof

Abstract

The invention relates to a body wave resonator and a processing method thereof. The body wave resonator comprises an acoustic mirror arranged on or embedded in a substrate and provided with a first edge and a second edge, a dielectric layer which is arranged on the substrate and in full contact with the two edges of the acoustic mirror, a first electrode which is arranged on the acoustic mirror and composed of a first terminal part, a second terminal part and a main part which is arranged between the first and the second terminal parts, a piezoelectric layer which is arranged on the first electrode and composed of a main part, a first terminal part and a second terminal part, and a second electrode which is arranged on the piezoelectric layer and consists of a main part and a second part, wherein the main part is located above the main part of the piezoelectric layer and connected with the second part, so that the connected joint of the main part and the second part is arranged between the first edge and the second edge of the acoustic mirror, and an air gap is formed between the second part of the second electrode and the first terminal part of the piezoelectric layer. The body wave resonator has simple structure and convenient processing, and can improve the quality factor, effective electro-mechanical coupling factor and static discharge resistance capacity.

Description

technical field [0001] The invention relates to a bulk wave resonator. In particular, it relates to a method that can improve the quality factor (Q) of the resonator, the effective electromechanical coupling coefficient A bulk wave resonator with anti-electrostatic discharge (ESD) capability and a processing method thereof. Background technique [0002] Thin film bulk wave resonators made of piezoelectric thin films with longitudinal resonance in the thickness direction have become a viable substitute for surface acoustic wave devices and quartz crystal resonators in mobile phone communications and high-speed serial data applications. The RF front-end bulk wave filter / duplexer provides superior filtering characteristics, such as low insertion loss, steep transition band, large power capacity, and strong anti-electrostatic discharge (ESD) capability. High frequency thin film bulk wave oscillator with ultra-low frequency temperature drift, low phase noise, low power consump...

AI Technical Summary

Problems solved by technology

If the surface of the inclined end face 1142 where the piezoelectric layer is deposited is rough, the Q value of the resonator and the effective value will be significantly worse

[0008] In addition, in the patent U.S.Pat.No.6,924,717 of Ginsburg et al., it is stated that when making a bottom electrode with a sloped end face, it is necessary to have good control over the slope angle, and the complexity of its processing and the cost of manufacturing will increase ( For example, dry etching takes a particularly long time)

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