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CN-122001324-A - Resonator and electronic device

CN122001324ACN 122001324 ACN122001324 ACN 122001324ACN-122001324-A

Abstract

The present invention relates to the field of acoustic resonators, and in particular, to a resonator and an electronic device. The resonator comprises a substrate, an acoustic mirror, a bottom electrode, a piezoelectric layer and a top electrode which are sequentially stacked, wherein an edge convex structure made of a nonmetallic material is introduced, and the resonator is divided into a first effective area in the center and second and third functional areas at the periphery of the first effective area. In the second region, the laminated structure includes an acoustic mirror, a bottom electrode, a piezoelectric layer, and the bump structure, but no top electrode, and in the third region, the laminated structure includes a piezoelectric layer, the bump structure, and a top electrode, but no bottom electrode. The design fundamentally destroys the formation condition of the parasitic resonator by combining the nonmetallic protrusion with the asymmetric electrode layout, effectively inhibits the secondary resonance and impedance curve bulge below spuriOus frequencies, and ensures excellent filter passband performance while improving parallel impedance. The invention also provides electronic equipment such as a filter comprising the resonator.

Inventors

  • ZHENG ZHIQIANG
  • ZHANG LANYUE
  • ZHANG WEI
  • JIANG XINGYONG
  • HAO LONG
  • HUANG YUANQING
  • WANG XULIANG

Assignees

  • 诺思(天津)微系统有限责任公司

Dates

Publication Date
20260508
Application Date
20260116

Claims (10)

  1. 1. A resonator comprising a substrate, an acoustic mirror, a bottom electrode, a piezoelectric layer and a top electrode which are laminated on the substrate, characterized in that, The resonator is provided with a first effective area, a second functional area and a third functional area which are positioned at the periphery of the first effective area; The first effective area is a main resonance area and is an overlapping area of the bottom electrode, the piezoelectric layer and the acoustic mirror along the thickness direction; an acoustic mirror, a bottom electrode, a piezoelectric layer and an edge bump structure which are stacked in a direction away from the substrate in the second functional region; A piezoelectric layer, an edge convex structure and a top electrode which are stacked in the direction away from the substrate in the third functional area; The edge projection is made of a non-metallic material.
  2. 2. The resonator of claim 1, wherein the material of the edge bump structure comprises at least one of SiO 2 、PSG、AlN、Si 3 N 4 and SiC.
  3. 3. The resonator according to claim 1, characterized in that the side of the edge relief structure remote from the substrate is provided with a top electrode etch stop layer.
  4. 4. The resonator of claim 1, further comprising an edge recess structure disposed on a side of the top electrode remote from the substrate; The edge recess structure is far away from the middle position of the first effective area.
  5. 5. The resonator of claim 1, further comprising a bottom electrode thickening layer; The bottom electrode thickening layer is arranged between the bottom electrode and the substrate; the bottom electrode and the bottom electrode thickening layer wrap the acoustic mirror; the bottom electrode is electrically connected to the bottom electrode thickening layer.
  6. 6. The resonator of claim 1, further comprising a top electrode thickening layer; the top electrode thickening layer is disposed on a side of the top electrode away from the substrate in the third functional region.
  7. 7. The resonator according to claim 1, characterized in that the piezoelectric layer comprises a first piezoelectric layer and a second piezoelectric layer arranged in a stack; in the second functional area, an edge structure is arranged between the first piezoelectric layer and the second piezoelectric layer; In the third functional area, an edge structure is arranged between the first piezoelectric layer and the second piezoelectric layer.
  8. 8. The resonator according to claim 7, characterized in that the edge structure is an air-filled cavity or a functional material reflecting sound waves.
  9. 9. A resonator according to claim 1, characterized in that the side of the resonator remote from the substrate is provided with a top electrode surface dielectric layer.
  10. 10. An electronic device comprising a resonator as claimed in any one of claims 1 to 9.

Description

Resonator and electronic device Technical Field The present invention relates to the field of acoustic resonators, and in particular, to a resonator and an electronic device. Background Bulk acoustic wave resonators are key components in modern radio frequency front end modules whose performance directly affects the bandwidth, insertion loss, and out-of-band rejection of the filter. To boost the parallel impedance (Rp) of the resonator, a bump structure is typically introduced at the edge of the resonant region. In conventional designs, the edge projection is typically formed of the same or similar metal material as the upper and lower electrodes. However, the edge bump structure of this metal material forms a parasitic resonator together with the top electrode, the bottom electrode and the piezoelectric layer. The parasitic resonator excites strong secondary resonant modes outside the primary resonant frequency, particularly below spuriOus frequencies. This can result in abnormal "bulge" of the impedance curve of the resonator near spuriOus, severely degrading the pass band flatness and rectangular coefficients of the filter. Therefore, how to effectively improve the parallel impedance of the resonator and inhibit the secondary resonance without introducing parasitic resonance is a technical problem to be solved in the art. Disclosure of Invention The invention provides a resonator and electronic equipment, which are used for solving the problem of abnormal bulge in the prior art. The invention provides a resonator, which comprises a substrate, an acoustic mirror, a bottom electrode, a piezoelectric layer and a top electrode, wherein the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode are arranged on the substrate in a stacked mode, The resonator is provided with a first effective area, a second functional area and a third functional area which are positioned at the periphery of the first effective area; an acoustic mirror, a bottom electrode, a piezoelectric layer and an edge bump structure which are stacked in a direction away from the substrate in the second functional region; A piezoelectric layer, an edge convex structure and a top electrode which are stacked in the direction away from the substrate in the third functional area; The edge projection is made of a non-metallic material. Optionally, the material of the edge bump structure includes at least one of SiO 2、PSG、AlN、Si3N4 and SiC. Optionally, a top electrode etching barrier layer is arranged on one side, away from the substrate, of the edge protruding structure. Optionally, the edge recess structure is distant from a middle position of the first effective area. Optionally, a bottom electrode thickening layer is also included; The bottom electrode thickening layer is arranged between the bottom electrode and the substrate; the bottom electrode and the bottom electrode thickening layer wrap the acoustic mirror; the bottom electrode is electrically connected to the bottom electrode thickening layer. Optionally, a top electrode thickening layer is also included; the top electrode thickening layer is disposed on a side of the top electrode away from the substrate in the third functional region. Optionally, the piezoelectric layer includes a first piezoelectric layer and a second piezoelectric layer that are stacked; in the second functional area, an edge structure is arranged between the first piezoelectric layer and the second piezoelectric layer; In the third functional area, an edge structure is arranged between the first piezoelectric layer and the second piezoelectric layer. Optionally, the edge structure is an air-filled cavity or a functional material that reflects sound waves. Optionally, a top electrode surface dielectric layer is disposed on a side of the resonator away from the substrate. The application provides an electronic device comprising a resonator as described above. In the scheme provided by the invention, the nonmetallic edge bulge is combined with a specific electrode missing layout, so that the condition of forming a parasitic resonator is fundamentally eliminated, and the key problem of bulge below spuriOus is solved. While parasitic resonance is restrained, higher parallel impedance (Rp) can be obtained through an edge structure, rs can be further reduced through various optimized structures (concave, electrode thickening, multilayer piezoelectricity and the like), and the Q value is improved. Drawings The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. Furthermore, these drawings and the written description are not intended to limit the scope of the inventive concept in any way, but to illustrate the inventive concept to those skilled in the art by referring to the specific embodiments. FIG. 1 is a schemat