Film bulk acoustic resonator and preparation method thereof

A thin-film bulk acoustic wave and resonator technology, applied in the field of resonators, can solve the problems of acoustic energy leakage, incomplete acoustic impedance mismatch, etc., achieve high frequency stability, improve Q value, and reduce loss

CN110311643APending Publication Date: 2019-10-08HANGZHOU SAPPLAND MICROELECTRONICS TECH CO LTD
0 Cites 4 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2019-10-08

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention provides a film bulk acoustic resonator and a preparation method thereof. The preparation method comprises the following steps: providing a first substrate and a second substrate; forming a first groove in the first substrate; forming at least one group of longitudinal Bragg reflection gratings on the second substrate, wherein each group of longitudinal Bragg reflection gratings comprises at least two thin film material layers with different acoustic impedances; bonding the side, provided with the longitudinal Bragg reflection grating, of the second substrate with the side, provided with the first groove, of the first substrate; forming a piezoelectric stacking structure on one side, deviating from the first substrate, of the second substrate; and forming at least one group of transverse reflection grids in the edge area of the piezoelectric stack structure to complete the preparation of the film bulk acoustic wave resonator. The prepared film bulk acoustic resonator is provided with reflecting gates in the transverse direction and the longitudinal direction, acoustic energy can be limited in an effective area of a device, the energy trapping effect can be achieved, the Q value of the device can be further improved, and therefore the resonator has high frequency stability.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a resonator, in particular to a film bulk acoustic wave resonator and a preparation method thereof. Background technique

[0002] At present, the most mainstream implementation methods of radio frequency filters are Surface Acoustic Wave (Surface Acoustic Wave, SAW) filters and filters based on Film Bulk Acoustic Resonator (Film Bulk Acoustic Resonator, FBAR) technology. Due to its own limitations, the SAW filter is more suitable for use below 1.5GHz. However, the current wireless communication protocol has long used a frequency band greater than 2.5GHz, and at this time a filter based on FBAR technology must be used.

[0003] There are many structures and preparation methods of FBAR devices. In the past structures and preparation methods, silicon is often used as the support structure, PSG is used as the sacrificial layer material, and finally an air gap is formed by etching the PSG sacrificial layer. In an ideal situation, ...

Examples

Embodiment Construction

[0061] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0062] Such as figure 1 As shown, the first aspect of the present invention is a thin film bulk acoustic resonator manufacturing method S100, which specifically includes the following steps:

[0063] S110, providing a first substrate and a second substrate;

[0064] S120, forming a first groove on the first substrate;

[0065] S130. Form at least one set of longitudinal Bragg reflection gratings on the second substrate, each set of longitudinal Bragg reflection gratings includes at least two thin film material layers with different acoustic impedances;

[0066] S140, bonding the side of the second substrate provided with the longitudinal Bragg grating to the side of the first substrate provided with the first groove;

...