US-12620964-B2 - Acoustic resonator device

Abstract

The present disclosure provides an acoustic resonator device, among other things. One example of the disclosed acoustic resonator device includes a substrate having a carrier layer, a first layer disposed over the carrier layer, and a piezoelectric layer disposed over the first layer. The acoustic resonator device is also disclosed to include an interdigitated metal disposed over the piezoelectric layer, where the interdigitated metal is configured to generate acoustic waves within an acoustically active region. The acoustic resonator device is further disclosed to include an acoustic wave scattering structure.

Inventors

• Richard Ruby
• Steve Gilbert
• David Archbold

Assignees

• AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED

Dates

Publication Date

20260505

Application Date

20211109

Claims (12)

1. 1 . A device, comprising: a substrate; a first filter device disposed over the substrate, wherein the first filter device comprises a first interdigitated metal, wherein the first interdigitated metal comprises a first thickness extending in a direction perpendicular to a surface of the substrate; a second filter device disposed over the substrate, wherein the second filter device comprises a second interdigitated metal, wherein the second interdigitated metal comprises a second thickness extending in the same direction as the first thickness, wherein the first thickness is greater than the second thickness; and a wave scattering structure disposed over in the substrate, wherein the wave scattering structure comprises: at least one apodized surface associated with a height roughness parameter; at least one void located within a distance of the at least one apodized surface that is less than the height roughness parameter and associated with a first width that is less than the first thickness; and at least one substrate seam associated with a second width that is less than the first thickness.
2. 2 . The device of claim 1 , wherein the first interdigitated metal of the first filter device comprises a first sublayer; a second sublayer disposed over the first sublayer; and a metal seam separating the first sublayer and the second sublayer.
3. 3 . The device of claim 2 , wherein the first sublayer comprises a first metallic material and the second sublayer comprises a second metallic material same as the first metallic material.
4. 4 . The device of claim 2 , wherein the first sublayer comprises a first metallic material and the second sublayer comprises a second metallic material different than the first metallic material.
5. 5 . The device of claim 2 , wherein the first sublayer comprises a first grain size and the second sublayer comprises a second grain size different than the first grain size.
6. 6 . The device of claim 2 , wherein the metal seam includes a separation line caused by a first metallic bondings of the first interdigitated metal differing from a second metallic bondings of the second interdigitated metal.
7. 7 . The device of claim 2 , wherein the first sublayer comprises a first sublayer thickness extending in the same direction as the first thickness and the second sublayer comprises a second sublayer thickness extending in the same direction as the first thickness, wherein the second sublayer thickness different from the first sublayer thickness.
8. 8 . The device of claim 7 , wherein the second sublayer thickness is less than 50% of the first sublayer thickness.
9. 9 . The device of claim 8 , wherein the second sublayer thickness is less than 15% of the first sublayer thickness.
10. 10 . The device of claim 7 , wherein the second thickness is substantially similar to the first sublayer thickness.
11. 11 . The device of claim 1 , wherein the first interdigitated metals comprises a first pitch separating a plurality of first fingers of the first interdigitated metal, wherein the second interdigitated metals comprises a second pitch separating a plurality of second fingers of the second interdigitated metal, and wherein the first pitch is different from the second pitch.
12. 12 . The device of claim 1 , wherein each of the first interdigitated metal and the second interdigitated metal is configured to generate acoustic waves within an acoustically active region.

Description

CROSS REFERENCE TO PRIORITY APPLICATIONS The present U.S. Utility Patent application claims priority pursuant to 35 U.S.C. § 120 as a continuation of U.S. Utility application Ser. No. 16/584,451, entitled “AN ACOUSTIC RESONATOR DEVICE”, filed Sep. 26, 2019. FIELD OF THE DISCLOSURE The present disclosure is generally directed toward acoustic resonator devices. BACKGROUND Electrical resonators are widely incorporated in modern electronic devices. For example, in wireless communications devices, radio frequency (RF) and microwave frequency resonators are used in filters, such as filters having electrically connected series and shunt resonators forming ladder and lattice structures. The filters may be included in a duplexer (e.g., diplexer, triplexer, quadplexer, quintplexer, etc.), connected between an antenna (there could be several antennas like for MIMO) and a transceiver for filtering received and transmitted signals. Various types of filters use mechanical resonators, such as acoustic wave resonators. Acoustic wave resonators convert electrical signals to mechanical signals or vibrations, and/or mechanical signals or vibrations to electrical signals. While certain surface modes are desired, certain unwanted modes can exist between the opposing faces of the piezoelectric material of the acoustic wave resonator. These unwanted modes are parasitic, and can impact the performance of filters comprising acoustic wave resonators. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure is described in conjunction with the appended figures: FIG. 1 is a block diagram depicting an illustrative acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 2A is a cross-sectional view of another illustrative acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 2B is a detailed view illustrating details of area A′ from FIG. 2A in accordance with at least some embodiments of the present disclosure; FIG. 2C is another detailed view illustrating further details of area A′ from FIG. 2A in accordance with at least some embodiments of the present disclosure; FIG. 3A is a cross-sectional view of another illustrative acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 3B is a detailed view illustrating details of area B′ from FIG. 3A in accordance with at least some embodiments of the present disclosure; FIG. 4A is a detailed view illustrating details of area C′ from FIG. 2A or FIG. 3A in accordance with at least some embodiments of the present disclosure; FIG. 4B is another detailed view illustrating further details of area C′ from FIG. 2A or FIG. 3A in accordance with at least some embodiments of the present disclosure; FIG. 4C is another detailed view illustrating further details of area C′ from FIG. 2A or FIG. 3A in accordance with at least some embodiments of the present disclosure; FIG. 5A is an isometric view of another acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 5B is an isometric view of another acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 6A illustrates a first possible method for producing an acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 6B illustrates a second possible method for producing an acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 6C illustrates a third possible method for producing an acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 6D illustrates a fourth possible method for producing an acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 6E illustrates a fifth possible method for producing an acoustic resonator device in accordance with at least some embodiments of the present disclosure; FIG. 7 is an isometric view of an acoustic resonator device illustrating various wave modes generated therein in accordance with at least some embodiments of the present disclosure; FIG. 8 is a diagram illustrating spurious modes of an acoustic resonator device with and without acoustic wave scattering structures; and FIG. 9 is a diagram illustrating energy propagation in an acoustic resonator device in accordance with at least some embodiments of the present disclosure. DETAILED DESCRIPTION Various aspects of the present disclosure will be described herein with reference to drawings that are schematic illustrations of idealized configurations. As such, variations from the shapes of the illustrations as a result, for example, manufacturing techniques and/or tolerances, are to be expected. Thus, the various aspects of the present disclosure presented throughout this document should not be construed as limited to the particular shapes of elements (e.g.,