# US 2018/0019726 A1 · Bulk acoustic wave resonator device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0019726 A1 - Document ID: US20180019726A1 - Status: Published application - Kind: A1 - Application number: 15/638,809 - Filed: 2017-06-30 - Published: 2018-01-18 - Earliest claimed: 2016-07-14 - Assignees: Samsung Electro-Mechanics Co., Ltd. - Applicants: Samsung Electro-Mechanics Co., Ltd. - Inventors: Sung HAN; Jae Chang LEE; Won HAN; Tae Yoon KIM; Jong Woon KIM; Tae Kyung LEE; Moon Chul LEE; Tae Hun LEE; Sung Min CHO; In Young KANG - Web page: https://patentgrep.com/patent/US20180019726A1 ## CPC - H03H 9/1014: {the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device} - H03H 9/02086: {Means for compensation or elimination of undesirable effects} - H03H 9/02102: {of temperature influence (cutting angles H03H9/02015)} - H03H 9/02118: {of lateral leakage between adjacent resonators} - H03H 9/02157: {Dimensional parameters, e.g. ratio between two dimension parameters, length, width or thickness} - H03H 9/172: {Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume} - H03H 9/173: {Air-gaps} - H03H 9/54: comprising resonators of piezoelectric or electrostrictive material (comprising resonators using surface acoustic waves H03H9/64) - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract A bulk acoustic wave resonator device includes: a substrate; a lower electrode disposed on the substrate; a piezoelectric layer disposed over a portion of the lower electrode; an upper electrode disposed on the piezoelectric layer; and a shape control layer covering an edge of a cavity disposed between the substrate and the lower electrode, wherein tensile stress is applied to the shape control layer during formation of the shape control layer. ## Claims ### Claim 1 A bulk acoustic wave resonator device, comprising: a substrate; a lower electrode disposed on the substrate; a piezoelectric layer covering a portion of the lower electrode; an upper electrode disposed on the piezoelectric layer; and a shape control layer disposed over an edge of a cavity disposed between the substrate and the lower electrode, wherein tensile stress is applied to the shape control layer during formation of the shape control layer. ### Claim 2 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein the shape control layer comprises any one of copper (Cu), nickel (Ni) and chromium (Cr), or a material containing any one of copper (Cu), nickel (Ni) and chromium (Cr). ### Claim 3 (depends on 2) The bulk acoustic wave resonator device of claim 2, wherein the tensile stress is applied to the shape control layer by applying heat or increasing a temperature of the substrate when the shape control layer is formed. ### Claim 4 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein the shape control layer comprises a polymer resin composite material. ### Claim 5 (depends on 4) The bulk acoustic wave resonator device of claim 4, wherein the tensile stress is applied to the shape control layer at the time of a heat treatment of either one of a drying operation and a curing operation. ### Claim 6 (depends on 1) The bulk acoustic wave resonator device of claim 1, further comprising a first layer disposed on the substrate and forming the cavity together with the substrate. ### Claim 7 (depends on 1) The bulk acoustic wave resonator device of claim 1, further comprising a protective layer covering a portion of the upper electrode. ### Claim 8 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein a portion of the shape control layer is disposed over the cavity, and remaining portions of the shape control layer are disposed outside the cavity. ### Claim 9 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein the shape control layer does not protrude outside the cavity. ### Claim 10 (depends on 9) The bulk acoustic wave resonator device of claim 9, wherein the shape control layer is disposed from a position corresponding to an edge of the cavity to a position corresponding to a central portion of the cavity. ### Claim 11 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein the shape control layer comprises a first shape control layer disposed on the lower electrode, and a second shape control layer disposed on the upper electrode. ### Claim 12 (depends on 11) The bulk acoustic wave resonator device of claim 11, wherein either one or both of the first shape control layer and the second shape control layer is disposed on a top surface of the piezoelectric layer. ### Claim 13 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein the substrate comprises supporting parts supporting edges of a resonating part, and the cavity is disposed inside the supporting parts. ### Claim 14 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein an overall thickness b of the lower electrode, the piezoelectric layer, and the upper layer, and a thickness a of the shape control layer disposed on either one or both of the upper electrode and the lower electrode satisfy a conditional equation 0.1≦a/b≦3. ### Claim 15 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein a length c for which either one of the upper electrode and the lower electrode overlaps the shape control layer satisfies a conditional equation 0.1≦c≦15 μm. ### Claim 16 (depends on 1) The bulk acoustic resonator device of claim 1, wherein a length d of the shape control layer disposed outside either one of the upper electrode and the lower electrode satisfies a conditional equation 0.2≦d≦30 μm. ### Claim 17 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein a length e of the shape control layer disposed over the cavity satisfies a conditional equation 0.1≦e≦15 μm. ### Claim 18 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein a height B of the cavity, which is a height of the cavity when there is no deflection of a resonating part of the bulk acoustic resonator device and a height A of the cavity, which is an increase in height of the cavity when a deflection of the resonating part occurs, satisfy a conditional equation 0.002≦A/(A+B)≦0.8. ### Claim 19 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein a height B of the cavity, which is a height of the cavity when there is no deflection of a resonating part, and a height A of the cavity, which is an increase in height of the cavity when a deflection of the resonating part occurs, satisfy a conditional equation A/B<1.0. ### Claim 20 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein a width C of a resonating part disposed over the cavity, and a height A of the cavity, which is an increase in height of the cavity when a deflection of the resonating part occurs, satisfy a conditional equation in which 0≦A/C≦0.1. ### Claim 21 (depends on 1) The bulk acoustic wave resonator device of claim 1, wherein the lower electrode, the piezoelectric layer, and the upper electrode deform to have an upwardly convex arch shape in response to the piezoelectric layer being deformed. ### Claim 22 A bulk acoustic wave resonator device, comprising: a substrate; a first layer disposed on the substrate and forming a cavity together with the substrate; a lower electrode disposed on the first layer; a piezoelectric layer covering a portion of the lower electrode; an upper electrode disposed on the piezoelectric layer; a protective layer covering a portion of the upper electrode; and a shape control layer disposed over an edge of the cavity, wherein tensile stress is applied to the shape control layer during formation of the shape control layer, and residual stress remains in the shape control layer. ### Claim 23 A bulk acoustic wave resonator device, comprising: a first layer disposed on a substrate, wherein a cavity is disposed between the substrate and the first layer; a lower electrode disposed on a portion of the first layer that covers the cavity in part; a piezoelectric layer disposed on a portion of the lower electrode; an upper electrode formed on the piezoelectric layer; and a shape control layer configured to cover a portion of the lower electrode at an end portion of the cavity and cover a portion of the upper electrode at another end portion of the cavity, wherein tensile stress is applied to the shape control layer during formation of the shape control layer.