# US 11,121,691 B2 · Resonator structure encapsulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,691 B2 - Document ID: US11121691B2 - Status: Granted - Kind: B2 - Application number: 16/348,830 - Filed: 2016-12-29 - Published: 2019-08-29 - Granted: 2021-09-14 - Earliest claimed: 2016-12-29 - Assignees: Intel Corporation - Applicants: Intel Corporation - Inventors: Kevin Lin; Kimin Jun; Edris Mohammed - Web page: https://patentgrep.com/patent/US11121691B2 ## CPC - H03H 3/02: for the manufacture of piezoelectric or electrostrictive resonators or networks (H03H3/08 takes precedence) - H03H 9/173: {Air-gaps} - H03H 2003/021: {the resonators or networks being of the air-gap type} - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract The RF filters used in conventional mobile devices often include resonator structures, which often require free-standing air-gap structure to prevent mechanical vibrations of the resonator from being damped by a bulk material. A method for fabricating a resonator structure comprises depositing a non-conformal thin-film to the resonator structure to seal air gap cavities in the resonator structure. ## Claims ### Claim 1 A method comprising; fabricating a resonator structure comprising a resonator and a first air gap cavity and a second air gap cavity, the first air gap cavity vertically over a location adjacent to a first side of the resonator, and the second air gap cavity vertically over a location adjacent to a second side of the resonator, the second side opposite the first side; and depositing a non-conformal thin-film over the resonator structure to seal the first air gap cavity and the second air gap cavity in the resonator structure. ### Claim 2 (depends on 1) The method of claim 1, wherein patterning the resonator structure comprises: patterning a bottom electrode on the sacrificial material; depositing a piezoelectric material on the bottom electrode; patterning a top electrode on the piezoelectric material; and patterning a top sacrificial material. ### Claim 3 (depends on 1) The method of claim 1, wherein fabricating the resonator structure further comprises: patterning a sacrificial material; and patterning the resonator structure. ### Claim 4 (depends on 3) The method of claim 3, wherein fabricating the resonator structure further comprises: depositing a spacer; and patterning a sidewall sacrificial material. ### Claim 5 (depends on 4) The method of claim 4, wherein fabricating the resonator structure further comprises: depositing an interlayer dielectric layer (ILD); and polishing the ILD. ### Claim 6 (depends on 5) The method of claim 5, wherein fabricating the resonator structure further comprises patterning release holes through the ILD to form the first air gap cavity and the second air gap cavity. ### Claim 7 (depends on 6) The method of claim 6, wherein fabricating the resonator structure further comprises: removing the sacrificial material; and depositing the non-conformal thin-film. ### Claim 8 (depends on 7) The method of claim 7, wherein depositing the non-conformal thin-film comprises depositing a plug material to fill the first air gap cavity and the second air gap cavity. ### Claim 9 (depends on 8) The method of claim 8, wherein the depositing of the non-conformal thin-film is applied via Chemical Vapor Deposition (CVD). ### Claim 10 (depends on 8) The method of claim 8, wherein the depositing of the non-conformal thin-film is applied via Physical Vapor Deposition (PVD). ### Claim 11 An integrated circuit (IC) comprising a resonator structure, the resonator structure including: a resonator having a first side and a second side, the second side opposite the first side; a first air gap cavity vertically over a location adjacent to the first side of the resonator; a second air gap cavity vertically over a location adjacent to the second side of the resonator; and a non-conformal thin-film sealing the first air gap cavity and the second air gap cavity. ### Claim 12 (depends on 11) The IC of claim 11, wherein the resonator comprises: a bottom electrode patterned over sacrificial material; a piezoelectric material deposited on the bottom electrode; and a top electrode patterned on the piezoelectric material. ### Claim 13 (depends on 12) The IC of claim 12, wherein the resonator structure further comprises: a bulk material; a sacrificial material deposited over the bulk material; and the resonator patterned over the sacrificial material. ### Claim 14 (depends on 13) The IC of claim 13, wherein the resonator structure further comprises: an interlayer dielectric layer (ILD) patterned over the resonator; a release hole patterned through the ILD to form the first air gap cavity and the second air gap cavity; and the non-conformal thin-film deposited over the ILD to seal the first air gap cavity and the second air gap cavity of the resonator structure. ### Claim 15 (depends on 14) The IC of claim 14, wherein the non-conformal thin-film is applied via Chemical Vapor Deposition (CVD). ### Claim 16 (depends on 14) The IC of claim 14, wherein the non-conformal thin-film is applied via Physical Vapor Deposition (PVD). ### Claim 17 A resonator structure, comprising: a resonator having a first side and a second side, the second side opposite the first side; a first air gap cavity vertically over a location adjacent to the first side of the resonator; a second air gap cavity vertically over a location adjacent to the second side of the resonator; and a non-conformal thin-film sealing the first air gap cavity and the second air gap cavity. ### Claim 18 (depends on 17) The resonator structure of claim 17, wherein the resonator comprises: a bottom electrode; a piezoelectric material deposited on the bottom electrode; and a top electrode patterned on the piezoelectric material. ### Claim 19 (depends on 18) The resonator structure of claim 18, further comprising: a bulk material; a sacrificial material deposited over the bulk material; and the resonator patterned over the sacrificial material. ### Claim 20 (depends on 19) The resonator structure of claim 19, further comprising: an interlayer dielectric layer (ILD) patterned over the resonator; a release hole patterned through the ILD to form the first air gap cavity and the second air gap cavity; and the non-conformal thin-film deposited over the ILD to seal the first air gap cavity and the second air gap cavity of the resonator structure.