# US 9,520,856 B2 · Acoustic resonator structure having an electrode with a cantilevered portion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,856 B2 - Document ID: US9520856B2 - Status: Granted - Kind: B2 - Application number: 14/165,301 - Filed: 2014-01-27 - Published: 2014-05-22 - Granted: 2016-12-13 - Earliest claimed: 2009-06-24 - Assignees: Avago Technologies General IP (Singapore) Pte. Ltd. - Applicants: Avago Technologies General IP (Singapore) Pte. Ltd. - Inventors: John Choy; Chris Feng; Phil Nikkel - Web page: https://patentgrep.com/patent/US9520856B2 ## CPC - H03H 9/171: {implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type} - H03H 9/02118: {of lateral leakage between adjacent resonators} - H03H 9/02149: {of ageing changes of characteristics, e.g. electro-acousto-migration} - H03H 9/132: {characterized by a particular shape} - H03H 9/173: {Air-gaps} - H03H 9/54: comprising resonators of piezoelectric or electrostrictive material (comprising resonators using surface acoustic waves H03H9/64) - H03H 9/706: {Duplexers} - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract An acoustic resonator comprises a first electrode and second electrode comprising a plurality of sides. At least one of the sides of the second electrode comprises a cantilevered portion. A piezoelectric layer is disposed between the first and second electrodes. A bridge disposed adjacent to one of the sides of the second electrode. ## Claims ### Claim 1 An acoustic resonator, comprising: a first electrode; a second electrode comprising a plurality of sides, at least one of the plurality of sides comprising a cantilevered portion, wherein the second electrode comprises a first surface disposed substantially at a first height, and the cantilevered portion comprises a second surface disposed substantially at a second height, which is higher than the first height; a piezoelectric layer disposed between the first and second electrodes, the cantilevered portion extending above the piezoelectric layer, wherein a gap exists between the cantilevered portion and the piezoelectric layer, wherein the piezoelectric layer extends over an edge of the first electrode; and a bridge disposed adjacent to one of the sides of the second electrode. ### Claim 2 (depends on 1) The acoustic resonator as claimed in claim 1, further comprising a reflective element disposed beneath the first electrode, the second electrode and the piezoelectric layer, wherein a contacting overlap of the reflective element, the first electrode, the second electrode and the piezoelectric layer comprises an active area of the acoustic resonator, and the bridge is disposed adjacent to the active area of the acoustic resonator. ### Claim 3 (depends on 2) The acoustic resonator as claimed in claim 2, wherein the cantilevered portion of the second electrode extends beyond a termination of the active area. ### Claim 4 (depends on 2) The acoustic resonator as claimed in claim 2, further comprising a frame element. ### Claim 5 (depends on 4) The acoustic resonator as claimed in claim 4, wherein the frame element is a recessed frame element. ### Claim 6 (depends on 4) The acoustic resonator claimed in claim 4, wherein the frame element comprises a raised frame element. ### Claim 7 (depends on 1) The acoustic resonator as claimed in claim 1, wherein the gap is a first gap, and the bridge comprises a second gap, which exists in a region between the second electrode and the piezoelectric layer. ### Claim 8 (depends on 1) The acoustic resonator as claimed in claim 1, wherein all but one of the plurality of sides of the second electrode comprises a cantilevered portion. ### Claim 9 (depends on 8) The acoustic resonator as claimed in claim 8, further comprising an electrical connection to the one of the plurality of sides of the second electrode that does not comprise a cantilevered portion. ### Claim 10 (depends on 9) The acoustic resonator as claimed in claim 9, wherein the electrical connection is made to the one of the plurality of sides of the second electrode that is connected to the bridge. ### Claim 11 (depends on 1) The acoustic resonator of claim 1, wherein the bridge comprises a third surface disposed substantially at a third height, and the third height is higher than the first height. ### Claim 12 An acoustic resonator, comprising: a first electrode; a second electrode comprising a plurality of sides, at least one of the plurality of sides comprising a cantilevered portion, wherein the second electrode comprises a first surface disposed substantially at first height, and the cantilevered portion comprises a second surface disposed substantially at a second height, which is higher than the first height; a piezoelectric layer disposed between the first and second electrodes; a reflective element disposed beneath the first electrode, the second electrode and the piezoelectric layer, a contacting overlap of the reflective element, the first electrode, the second electrode and the piezoelectric layer defining an active area of the acoustic resonator, wherein the first electrode substantially covers the reflective element, and the piezoelectric layer extends over an edge of the first electrode; and a bridge adjacent to a termination of the active area of the acoustic resonator, wherein the bridge overlaps a portion of the first electrode. ### Claim 13 (depends on 12) An acoustic resonator as claimed in claim 12, wherein the cantilevered portion of the second electrode extends beyond a termination of the active area. ### Claim 14 (depends on 12) An acoustic resonator as claimed in claim 12, further comprising a frame element. ### Claim 15 (depends on 14) An acoustic resonator as claimed in claim 14, wherein the frame element is a recessed frame element. ### Claim 16 (depends on 14) An acoustic resonator as claimed in claim 14, wherein the frame element comprises a raised frame element. ### Claim 17 (depends on 12) An acoustic resonator as claimed in claim 12, wherein the bridge comprises a gap, and the gap exists in a region between the second electrode and the piezoelectric layer. ### Claim 18 (depends on 12) An acoustic resonator as claimed in claim 12, wherein the bridge comprises a third surface disposed substantially at a third height, and the third height is higher than the first height. ### Claim 19 (depends on 12) An acoustic resonator as claimed in claim 12, wherein all but one of the plurality of sides of the second electrode comprise the cantilevered portion. ### Claim 20 (depends on 19) An acoustic resonator as claimed in claim 19, further comprising an electrical connection to the one of the plurality of sides of the second electrode that does not comprise a cantilevered portion. ### Claim 21 (depends on 20) An acoustic resonator as claimed in claim 20, wherein the electrical connection is made to the one of the plurality of sides of the second electrode that is connected to the bridge. ### Claim 22 An acoustic resonator, comprising: a first electrode; a second electrode comprising a plurality of sides, at least one of the plurality of sides comprising a cantilevered portion, wherein the second electrode comprises a first surface disposed substantially at a first height, and the cantilevered portion comprises a second surface disposed substantially at a second height, which is higher than the first height; and a piezoelectric layer disposed between the first and second electrodes, the cantilevered portion extending above the piezoelectric layer, wherein a gap exists between the cantilevered portion and the piezoelectric layer, wherein the piezoelectric layer extends over an edge of the first electrode. ### Claim 23 (depends on 22) The acoustic resonator as claimed in claim 22, further comprising a reflective element disposed beneath the first electrode, the second electrode and the piezoelectric layer, wherein a contacting overlap of the reflective element, the first electrode, the second electrode and the piezoelectric layer comprises an active area of the acoustic resonator, and a bridge is disposed adjacent to the active area of the acoustic resonator. ### Claim 24 (depends on 23) The acoustic resonator as claimed in claim 23, wherein the cantilevered portion of the second electrode extends beyond a termination of the active area. ### Claim 25 (depends on 23) The acoustic resonator as claimed in claim 23, further comprising a frame element. ### Claim 26 (depends on 25) The acoustic resonator as claimed in claim 25, wherein the frame element is a recessed frame element. ### Claim 27 (depends on 25) The acoustic resonator claimed in claim 25, wherein the frame element comprises a raised frame element. ### Claim 28 (depends on 22) The acoustic resonator as claimed in claim 22, wherein all but one of the plurality of sides of the second electrode comprises a cantilevered portion. ### Claim 29 (depends on 28) The acoustic resonator as claimed in claim 28, further comprising an electrical connection to the one of the plurality of sides of the second electrode that does not comprise a cantilevered portion.