Thin film bulk acoustic resonator

Abstract

The invention relates to the field of communication, and provides a film bulk acoustic wave resonator which comprises a top electrode, a piezoelectric layer, a bottom electrode, an acoustic reflectionstructure, a substrate and a temperature compensation layer with the thickness larger than a preset value, and the temperature compensation layer is also used for adjusting the area of the film bulkacoustic wave resonator. Compared with the prior art, the thin film bulk acoustic wave resonator has a high electromechanical coupling coefficient, the temperature frequency drift coefficient of the thin film bulk acoustic wave resonator can be kept unchanged, and the area of the thin film bulk acoustic wave resonator can be increased.

Description

technical field [0001] The invention relates to the communication field, in particular to a film bulk acoustic wave resonator. Background technique [0002] In recent years, with the continuous development of wireless communication technology, the advantages of thin film bulk acoustic wave resonators in radio frequency front-end applications have become more and more obvious. Among them, thin film bulk acoustic wave resonators are the basic components of bulk acoustic wave devices. This type of resonator is a component based on piezoelectric technology, and its size is extremely small, which is 4 to 5 orders of magnitude smaller than that of components that simply use electromagnetic waves as propagation signals; the insertion loss is small, and the Q value is high (up to 1000 or more) ) (Q value is the quality factor value), the operating frequency is high, and the withstand power capacity is larger than that of the surface acoustic wave device; and it is compatible with th...

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Problems solved by technology

[0005] However, if figure 1 As shown (the horizontal axis is the doping amount of Sc, and the vertical axis is the temperature frequency drift coefficient), with the increase of the content of rare earth elements doped in the piezoelectric layer of the resonator ( figure 1 The rare earth element in is scandium Sc), which will lead to the deterioration of the temperature frequency drift coefficient of the resonator, and will also be accompanied by the reduction of the resonator area, and the decrease of the resonator area will lead to the increase of the leaked energy in the effective area of ​​the resonator , thus lowering its Q and leading to increased spurs in the resonator

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