Film bulk acoustic wave resonator and communication device

Abstract

The invention discloses a film bulk acoustic resonator and a communication device thereof. The resonator includes a substrate, a groove is formed in the upper surface of the substrate; the groove is provided with a boundary; a bottom electrode layer, a piezoelectric layer and a top electrode layer are sequentially arranged on the substrate; a first temperature compensation layer is arranged between the bottom electrode layer and the piezoelectric layer; a second temperature compensation layer is arranged between the piezoelectric layer and the top electrode layer, protection cavities are formed in the side, facing the first temperature compensation layer, of the piezoelectric layer and the other side, facing the second temperature compensation layer, of the piezoelectric layer respectively; the first temperature compensation layer and the second temperature compensation layer are placed in the protection cavities respectively, and the lengths of the protection cavities extend out of the boundary of the groove. According to the resonator, the protection cavity is formed in one side, close to the temperature compensation layer, of the piezoelectric layer; and the temperature compensation layer is embedded into the protection cavity, so that the end part of the temperature compensation layer is covered with a thicker piezoelectric material and plays a protection role, the etchingcapability of the etching solution is effectively weakened, the temperature compensation layer is prevented from being eroded by the sacrificial layer etching solution, and the temperature stability of the resonator is ensured.

Description

technical field [0001] The invention relates to the technical field of wireless communication radio frequency front-end devices, in particular to a thin film bulk acoustic wave resonator and a communication device. Background technique [0002] With the development of wireless communication technology and smart phones, the RF front-end has higher and higher requirements on the performance indicators and integration of components. RF front-end filters, duplexers, and multiplexers based on thin film bulk acoustic wave devices have been widely used in smartphones, communication terminals, and In the communication base station, it will be applied in the communication equipment of the Internet of Vehicles, industrial control and other Internet of Things terminals in the future. In addition, oscillators based on thin film bulk acoustic wave devices are of great application value in high-speed serial data devices such as SATA hard drives, USB3.0 standard PC peripherals, C-type int...

AI Technical Summary

Problems solved by technology

Since the temperature compensation layer and the sacrificial layer are usually made of silicon dioxide or doped silicon dioxide, the etchant for the sacrificial layer will also cause corrosion damage to the temperature compensation layer, thereby affecting the temperature stability of the thin film bulk acoustic resonator

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