ACOUSTIC WAVE RESONATOR WITH LOW/ZERO-ELECTROMECHANICAL COUPLING AT BORDER REGION

Application No. 18/150,621

• Filed: Jan 05, 2023
• Priority: Jan 11, 2022 — provisional 63/298,248
  • Mar 29, 2022 — provisional 63/324,961
• Examiner: MATA, SARA M
• Art Unit: 2837
• Tech Center: 2800 — Semiconductors & Electrical Systems
• Assignee: Qorvo US Inc.
• OA Round: 2 (Final)

Office Action

Response After Non-Final
This Office action is in response to the amendment filed on 5/14/2026.
Claims 1-21 are pending in the application.
Claims 1-9 and 21 are rejected.
Claims 10-20 are withdrawn.
Claims 3 and 8-9 are amended.
In the event the determination of the status of the application as subject to AIA 35
U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Response to Arguments
The applicant's arguments filed May 14, 2026 have been fully considered
and are respectfully found persuasive in part and unpersuasive in part.
The applicant argues the following:
[1] Claim objections have been addressed and should be withdrawn.

[2] Prior art of record fails to teach “the ferroelectric BO portion has a first polarization and a first electromechanical coupling coefficient, and the ferroelectric central portion has a second polarization and a second electromechanical coupling coefficient, wherein an absolute value of the first polarization is less than an absolute value of the second polarization, and the first electromechanical coupling coefficient is less than the second electromechanical coupling coefficient” in Claims 1 and 21.

Regarding [1], the examiner respectfully agrees and the claim objections raised in the most recent office action are hereby withdrawn.
Regarding [2], the examiner respectfully disagrees because Burak teaches distinct central and edge regions with distinct material properties and functions. First, while the prior art of record does not explicitly disclose the absolute value of polarization and the electromechanical coupling coefficient of each region it is clear that the central and edge regions have different absolute values of polarization and electromechanical coupling coefficients. This is clear because one region, the edge region 153 is etched and the central region is not etched and absolute values of polarization and electromechanical coupling coefficients are a function of material thickness. The etching would necessarily alter thickness, and therefore, the absolute values of polarization and the electromechanical coupling coefficients given their dependence on the material thickness. Second, while the prior art of record does not explicitly disclose that the central region has a larger absolute value of polarization and electromechanical coupling coefficient than the edge region it is clear that the two regions have different absolute values of polarization and electromechanical coupling coefficients and that the central unetched region would have the higher electromechanical coupling coefficient. As aforementioned, absolute values of polarization and electromechanical coupling coefficients are a function of material thickness, and therefore, an unetched thicker material would have a higher absolute value of polarization and electromechanical coupling coefficient than an etched thinner material.

DETAILED ACTION
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of AIA 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –

(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.

Claims 1-9 and 21 are rejected under AIA 35 U.S.C. 102(a)(2) as being
anticipated by Burak et al. (U.S. Publication No. 20230170876; hereinafter “Burak”).
Regarding claim 1, Burak discloses a Bulk Acoustic Wave (BAW) resonator, comprising: a bottom electrode (Fig. 1A, 121); a top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151); and a ferroelectric layer (Fig. 1A; [0087]; [0091]) sandwiched between (Fig. 1A) the bottom electrode (Fig. 1A, 121) and the top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151), wherein: the ferroelectric layer (Fig. 1A; [0087]; [0091]) is formed (Fig. 1A) of a ferroelectric material (Fig. 1A; [0087]; [0091]), which has a box-shape polarization-electric field (P-E) curve (Fig. 1A; [0087]; [0091]; Examiner’s Note: The P-E curve for a ferroelectric is box-shaped.); the ferroelectric layer (Fig. 1A; [0087]; [0091]) includes (Fig. 1A) a ferroelectric border (BO) portion (Fig. 1A, 153 border portion of Ferroelectric layer) positioned (Fig. 1A) at a periphery (Fig. 1A, periphery 153) of the ferroelectric layer (Fig. 1A; [0087]; [0091]) and a ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) surrounded (Fig. 1A) by the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer); the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) has a first polarization (Fig. 1A, polarization of 153 border portion of Ferroelectric layer) and a first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer), and the ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) has a second polarization (Fig. 1A, polarization of central portion of Ferroelectric layer) and a second electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of central portion of Ferroelectric layer), wherein an absolute value (Fig. 1A, absolute value of polarization of 153 border portion of Ferroelectric layer) of the first polarization (Fig. 1A, polarization of 153 border portion of Ferroelectric layer) is less than (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”) an absolute value (Fig. 1A, absolute value of polarization of polarization of central portion of Ferroelectric layer) of the second polarization (Fig. 1A, polarization of central portion of Ferroelectric layer), and the first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer) is less than (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”) the second electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of central portion of Ferroelectric layer); and the ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) is configured to provide (Fig. 1A) a resonance (Fig. 1A, 100 resonance) of the BAW resonator (Fig. 1A, 100).
Regarding claim 2, Burak discloses the BAW resonator of claim 1 wherein the absolute value of the first polarization (Fig. 1A, absolute value of polarization of 153 border portion of Ferroelectric layer) is constant (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”), and the first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer) is constant (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”).
Regarding claim 3, Burak discloses the BAW resonator of claim 2 wherein the first polarization (Fig. 1A, polarization of 153 border portion of Ferroelectric layer) of the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) is a zero polarization (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”), and the first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer) of the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) is a zero electromechanical coupling coefficient (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”).
Regarding claim 4, Burak discloses the BAW resonator of claim 1 wherein the absolute value of the first polarization (Fig. 1A, absolute value of polarization of 153 border portion of Ferroelectric layer) gradually reduces (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”) from an interior side (Fig. 1A, interior side of 153 border portion of Ferroelectric layer) of the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) towards (Fig. 1A) an outer edge (Fig. 1A, outer edge of 153 border portion of Ferroelectric layer) of the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer), and the first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer) gradually reduces (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”) from the interior side (Fig. 1A, interior side of 153 border portion of Ferroelectric layer) of the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) towards (Fig. 1A) the outer edge (Fig. 1A, outer edge of 153 border portion of Ferroelectric layer) of the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer).
Regarding claim 5, Burak discloses the BAW resonator of claim 1 wherein the top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151) comprises a top electrode base (Fig. 1A, 137) over (Fig. 1A) the ferroelectric layer (Fig. 1A; [0087]; [0091]) and a BO ring (Fig. 1A, border ring protruding from periphery of 137) protruding (Fig. 1A) from a periphery (Fig. 1A, periphery of 37) of the top electrode base (Fig. 1A, 137), wherein: a region (Fig. 1A, region of 100)of the BAW resonator (Fig. 1A, 100), within which (Fig. 1A) the BO ring (Fig. 1A, border ring protruding from periphery of 137) is located (Fig. 1A) is a BO region (Fig. 1A, location in 100 within which border ring protruding from periphery of 137 is located); and the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) is confined within (Fig. 1A) the BO region (Fig. 1A, location in 100 within which border ring protruding from periphery of 137 is located) and aligned underneath (Fig. 1A) the BO ring (Fig. 1A, border ring protruding from periphery of 137), while the ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) is not covered (Fig. 1A) by the BO ring (Fig. 1A, border ring protruding from periphery of 137).
Regarding claim 6, Burak discloses the BAW resonator of claim 1 wherein the top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151) has a flat shape (Fig. 1A, flat shape of 37/139/141/143/145/147/149/151).
Regarding claim 7, Burak discloses the BAW resonator of claim 1 wherein the ferroelectric material (Fig. 1A; [0087]; [0091]) is scandium aluminum nitride (ScxAl1-xN) (Fig. 1A; [0087]; [0091]) and the P-E curve (Fig. 1A; [0091] – “ScxAl1-xN”) of ScxAl1-N (Fig. 1A; [0091] – “ScxAl1-xN”) is dependent (Fig. 1A; [0091] – “ScxAl1-xN”) on a scandium concentration x (Fig. 1A; [0091] – “ScxAl1-xN”).
Regarding claim 8, Burak discloses the BAW resonator of claim 1 further comprises a bottom Bragg reflector (Fig. 1A, 113; [0121]) formed underneath (Fig. 1A) the bottom electrode (Fig. 1A, 121).
Regarding claim 9, Burak discloses the BAW resonator of claim 8 further comprises a top Bragg reflector (Fig. 1A, 115; [0132]) formed over (Fig. 1A) the top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151).
Regarding claim 21, Burak discloses a system, comprising: a radio-frequency (RF) input circuitry (Figs. 1A/11; Fig. 11, 9515N input circuitry); a RF output circuitry (Figs. 1A/11; Fig. 11, 9515N output circuitry); and a filter circuitry (Figs. 1A/11A; Fig. 11, 9112J/9114J/9116J/9118J), which includes at least one Bulk Acoustic Wave (BAW) resonator (Figs. 1A/11; Fig. 1A, 100; Fig. 11, 9112J/9114J/9116J/9118J; [0433]), connected between the RF input circuitry (Figs. 1A/11; Fig. 11, 9515N input circuitry) and the RF output circuitry (Figs. 1A/11; Fig. 11, 9515N output circuitry), wherein the at least one BAW resonator (Figs. 1A/11; Fig. 1A, 100; Fig. 11, 9112J/9114J/9116J/9118J; [0433]) comprises: a bottom electrode (Fig. 1A, 121); a top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151); and a ferroelectric layer (Fig. 1A; [0087]; [0091]) sandwiched between (Fig. 1A) the bottom electrode (Fig. 1A, 121) and the top electrode structure (Fig. 1A, 137/139/141/143/145/147/149/151), wherein: the ferroelectric layer (Fig. 1A; [0087]; [0091]) is formed (Fig. 1A) of a ferroelectric material (Fig. 1A; [0087]; [0091]), which has a box-shape polarization-electric field (P-E) curve (Fig. 1A; [0087]; [0091]; Examiner’s Note: The P-E curve for SCALN is box-shaped.); the ferroelectric layer (Fig. 1A; [0087]; [0091]) includes (Fig. 1A) a ferroelectric border (BO) portion (Fig. 1A, 153 border portion of Ferroelectric layer) positioned (Fig. 1A) at a periphery (Fig. 1A, periphery 153) of the ferroelectric layer (Fig. 1A; [0087]; [0091]) and a ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) surrounded (Fig. 1A) by the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer); the ferroelectric BO portion (Fig. 1A, 153 border portion of Ferroelectric layer) has a first polarization (Fig. 1A, polarization of 153 border portion of Ferroelectric layer) and a first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer), and the ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) has a second polarization (Fig. 1A, polarization of central portion of Ferroelectric layer) and a second electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of central portion of Ferroelectric layer), wherein an absolute value (Fig. 1A, absolute value of polarization of 153 border portion of Ferroelectric layer) of the first polarization (Fig. 1A, polarization of 153 border portion of Ferroelectric layer) is less than (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”) an absolute value (Fig. 1A, absolute value of polarization of polarization of central portion of Ferroelectric layer) of the second polarization (Fig. 1A, polarization of central portion of Ferroelectric layer), and the first electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of 153 border portion of Ferroelectric layer) is less than (Fig. 1A; [0146] – “The etched edge region may, but need not, assist with acoustic isolation of the resonators. The etched edge region may, but need not, help with avoiding acoustic losses for the resonators.”) the second electromechanical coupling coefficient (Fig. 1A, electromechanical coupling coefficient of central portion of Ferroelectric layer); and the ferroelectric central portion (Fig. 1A, central portion of Ferroelectric layer) is configured to provide (Fig. 1A) a resonance (Figs. 1A/11; Fig. 1A, resonance of 100; Fig. 11, resonance of 9112J/9114J/9116J/9118J; [0433]) of the BAW resonator (Figs. 1A/11; Fig. 1A, 100; Fig. 11, 9112J/9114J/9116J/9118J; [0433]).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time
policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Any inquiry concerning this communication should be directed to MONICA MATA
whose telephone number is [phone]. The examiner can normally be reached on Monday thru Friday from 7:30 AM to 5:00 PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s
supervisor, Dedei Hammond, can be reached on [phone]. The fax phone number for the organization where this application or proceeding is assigned is [phone].
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/MONICA MATA/
Patent Examiner, Art Unit 2837

23 July 2026

/EMILY P PHAM/Primary Examiner, Art Unit 2837

Prosecution Timeline

• Jan 05, 2023: Application Filed
• Mar 05, 2026: Non-Final Rejection mailed — §102
• May 14, 2026: Response Filed
• Jul 28, 2026: Final Rejection mailed — §102 (current)