# US 12,009,806 B2 · Frequency control of spurious shear horizontal mode by adding high velocity layer in a lithium niobate filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,806 B2 - Document ID: US12009806B2 - Status: Granted - Kind: B2 - Application number: 17/368,948 - Filed: 2021-07-07 - Published: 2021-10-28 - Granted: 2024-06-11 - Earliest claimed: 2018-06-13 - Assignees: Skyworks Solutions, Inc. - Applicants: Skyworks Solutions, Inc. - Inventors: Tomoya Komatsu - Web page: https://patentgrep.com/patent/US12009806B2 ## CPC - H03H 9/02228: {Guided bulk acoustic wave devices or Lamb wave devices having interdigital transducers situated in parallel planes on either side of a piezoelectric layer} - H03H 9/6483: {Ladder SAW filters} - H03H 9/02559: {of lithium niobate or lithium-tantalate substrates} - H03H 9/02834: {of temperature influence (cut angles H03H9/02543)} - H03H 9/14541: {Multilayer finger or busbar electrode} - H03H 9/205: having multiple resonators (crystal tuning forks H03H9/21) - H03H 9/54: comprising resonators of piezoelectric or electrostrictive material (comprising resonators using surface acoustic waves H03H9/64) - H03H 9/6496: {Reducing ripple in transfer characteristic} - H03H 9/72: Networks using surface acoustic waves - H03H 9/6436: {having one acoustic track only} - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract An electronic device comprises a first surface acoustic wave (SAW) resonator and a second SAW resonator, each including interleaved interdigital transducer (IDT) electrodes, the first and second SAW resonators being formed on a same piezoelectric substrate, the first SAW resonator having IDT electrodes with a different finger pitch than the IDT electrodes of the second SAW resonator; a dielectric material layer disposed on the IDT electrodes of the first and second SAW resonators; and a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes of the first SAW resonator, the second SAW resonator lacking a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes. ## Claims ### Claim 1 An electronic device comprising: a first surface acoustic wave (SAW) resonator and a second SAW resonator, each including interleaved interdigital transducer (IDT) electrodes, the first and second SAW resonators being formed on a same piezoelectric substrate, the first SAW resonator having IDT electrodes with a different finger pitch than the IDT electrodes of the second SAW resonator; a dielectric material layer disposed on the IDT electrodes of the first and second SAW resonators; and a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes of the first SAW resonator and within the dielectric material layer disposed on the IDT electrodes of the second SAW resonator, the dielectric material layer disposed on the IDT electrodes of the first SAW resonator having a same normalized thickness as a normalized thickness of the dielectric material layer disposed on the IDT electrodes of the second SAW resonator, a normalized thickness of the high velocity layer disposed within the dielectric material layer covering the IDT electrodes of the first SAW resonator being different from a normalized thickness of the high velocity layer disposed within the dielectric material layer covering IDT electrodes of the second SAW resonator. ### Claim 2 (depends on 1) The electronic device of claim 1 wherein the dielectric material layer comprises silicon dioxide. ### Claim 3 (depends on 2) The electronic device of claim 2 wherein the high velocity layer comprises one or more of silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxide, or diamond. ### Claim 4 (depends on 1) The electronic device of claim 1 wherein the high velocity layer is located between about 0% and about 40% of the thickness of the dielectric material layer above the IDT electrodes of the first SAW resonator. ### Claim 5 (depends on 1) The electronic device of claim 1 included in an electronic device module. ### Claim 6 (depends on 5) The electronic device of claim 5 wherein the electronic device module is a radio frequency device module. ### Claim 7 An electronic device comprising: a first filter and a second filter, each including surface acoustic wave (SAW) resonators disposed on a same piezoelectric substrate, the first filter having a passband different than a passband of the second filter; a dielectric film covering the SAW resonators of the first and second filters; and a high velocity layer disposed within the dielectric film covering the SAW resonators of the first filter and at least one of the SAW resonators of the second filter, the dielectric film covering the SAW resonators of the first filter having a same normalized thickness as a normalized thickness of the dielectric film covering the SAW resonators of the second filter, a normalized height of the high velocity layer disposed within the dielectric film covering the SAW resonators of the first filter being different from a normalized height of the high velocity layer disposed within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 8 (depends on 7) The electronic device of claim 7 wherein the high velocity layer disposed within the dielectric film covering at least one of the SAW resonators of the first filter has a same thickness as the high velocity layer disposed within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 9 (depends on 7) The electronic device of claim 7 wherein the high velocity layer disposed within the dielectric film covering at least one of the SAW resonators of the first filter has a different thickness than the high velocity layer disposed within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 10 (depends on 7) The electronic device of claim 7 wherein a normalized thickness of the high velocity layer within the dielectric film covering at least one of the SAW resonators of the first filter is the same as the normalized thickness of the high velocity layer within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 11 (depends on 7) The electronic device of claim 7 wherein the dielectric film covering the SAW resonators of the first filter includes an upper portion disposed on an upper surface of the high velocity layer and a lower portion disposed between a lower surface of the high velocity layer and upper surfaces of interdigital transducer electrodes of at least one of the SAW resonators of the first filter. ### Claim 12 (depends on 11) The electronic device of claim 11 wherein a thickness of the lower portion of the dielectric film covering the at least one of the SAW resonators of the first filter has a different thickness than a lower portion of the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 13 (depends on 7) The electronic device of claim 7 wherein a normalized height of the high velocity layer within the dielectric film covering at least one of the SAW resonators of the first filter is the same as the normalized height of the high velocity layer within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 14 (depends on 13) The electronic device of claim 13 wherein a normalized thickness of the high velocity layer within the dielectric film covering at least one of the SAW resonators of the first filter is different than the normalized thickness of the high velocity layer within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 15 (depends on 7) The electronic device of claim 7 wherein a thickness of the high velocity layer within the dielectric film covering at least one of the SAW resonators of the first filter has a different thickness than the high velocity layer within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 16 (depends on 15) The electronic device of claim 15 wherein a normalized thickness of the high velocity layer within the dielectric film covering at least one of the SAW resonators of the first filter is the same as the normalized thickness of the high velocity layer within the dielectric film covering the at least one of the SAW resonators of the second filter. ### Claim 17 (depends on 7) The electronic device of claim 7 included in an electronic device module. ### Claim 18 (depends on 17) The electronic device of claim 17 wherein the electronic device module is a radio frequency device module. ### Claim 19 An electronic device comprising: a first surface acoustic wave (SAW) resonator and a second SAW resonator, each including interleaved interdigital transducer (IDT) electrodes, the first and second SAW resonators being formed on a same piezoelectric substrate, the first SAW resonator having IDT electrodes with a different finger pitch than the IDT electrodes of the second SAW resonator; a dielectric material layer disposed on the IDT electrodes of the first and second SAW resonators; and a high velocity layer disposed within the dielectric material layer disposed on the IDT electrodes of the first SAW resonator and within the dielectric material layer disposed on the IDT electrodes of the second SAW resonator, the dielectric material layer disposed on the IDT electrodes of the first SAW resonator having a same normalized thickness as a normalized thickness of the dielectric material layer disposed on the IDT electrodes of the second SAW resonator, a normalized height of the high velocity layer disposed within the dielectric material layer covering the IDT electrodes of the first SAW resonator being different from a normalized height of the high velocity layer disposed within the dielectric material layer covering IDT electrodes of the second SAW resonator. ### Claim 20 (depends on 19) The electronic device of claim 19 wherein the high velocity layer is disposed within the dielectric material layer disposed on the IDT electrodes of the first SAW resonator at a same height as a height at which the high velocity layer is disposed within the dielectric material layer disposed on the IDT electrodes of the second SAW resonator.