MEMS RESONATOR AND MANUFACTURING METHOD

Application No. 18/002,391

• Filed: Dec 19, 2022
• Priority: Jul 03, 2020 — FI 20205711
  • Jul 01, 2021 — nonprovisional of PCTFI2021050506
• Examiner: MATA, SARA M
• Assignee: Kyocera Technologies OY
• OA Round: 1 (Non-Final)

Office Action

Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined
under the first inventor to file provisions of the AIA .
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.
Election/Restrictions
Applicant’s election without traverse of Group I (Claims 1-17) in the reply filed
on February 17, 2026 is acknowledged.
Claim 18 is withdrawn from further consideration pursuant to 37 CPR 1.142(b)
as being drawn to nonelected inventions, there being no allowable generic or linking claim.
DETAILED ACTION
Foreign Priority
Receipt is acknowledged of certified copies of papers submitted under 35 U.S.C.
119 (a)-(d), which papers have been placed of record in the file.
Specification
The title is objected to for failure to be sufficiently descriptive.
The specification has not been checked to the extent necessary to determine the
presence of all possible minor errors. The applicant's cooperation is requested in correcting any errors of which the applicant may become aware in the specification.
Claim Objections
Claims 1-2, 4, 6, 8,11-12, and 15-17 are objected to because of the following
informalities:
Claim 1
Line 1, “a MEMS (microelectromechanical system)” should be --a microelectromechanical system (MEMS)--
Line 4, “said first” should be --the first--
Line 4, “said second” should be --the second--
Claim 2
Line 2, “of the mentioned three layers” should be –above the piezoelectric layer and the second layer of single-crystalline silicon--
Claim 4
Line 4, “(L3)” should be deleted.
Claim 6
Line 2, “the first single-crystalline silicon layer” should be --the first layer of single-crystalline silicon--
Line 2, “the second single-crystalline silicon layer” should be --the second layer of single-crystalline silicon--
Claim 8
Line 2, “the direction” should be --a direction--
Claim 11
Line 4, “, for example,” should be deleted.
Claim 12
Line 2, “the resonator” should be --the MEMS resonator--
Claim 15
Line 2, “said additional” should be --the additional--
Claim 16
Line 3, “the whole first” should be --the first--
Line 3, “said vertical” should be --the vertical--
Claim 17
Line 1, “finetuning” should be –fine-tuning--
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.

Claim 11 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to
particularly point out and distinctly claim the subject matter which the applicant regards as the invention.
In Claim 11, it is unclear whether “substantially” refers to a fourth, a third, half, more than half, entirely, or some other quantity. The specification does not provide some standard for measuring “substantially.” One of ordinary skill in the art, in view of the prior art and the status of the art, would not be reasonably apprised of the scope of “substantially” from the drawings alone. The scope of the term is not understood when read in light of the specification because the specification does not provide a standard for measuring “substantially.” Therefore, the examiner has understood the term “substantially” to designate entirely.
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.

Claims 1-17 are rejected under AIA 35 U.S.C. 102(a)(1) as being anticipated
by Saarela et al. (U.S. Publication No. 20220166406; hereinafter “Saarela”).
Regarding claim 1, Saarela discloses a MEMS (microelectromechanical system) resonator, comprising: a first layer of single-crystalline silicon (Fig. 12, L1; [0100]); a second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]); and a piezoelectric layer (Fig. 12, L2; [0099]) in between (Fig. 12) said first layer of single-crystalline silicon (Fig. 12, L1; [0100]) and said second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]).
Regarding claim 2, Saarela discloses the MEMS resonator of claim 1, wherein the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) is an uppermost layer (Fig. 12) of the mentioned three layers (Fig. 12, L1-L4) and is used (Fig. 12; [0101]-[0102]) as an electrode (Fig. 12; [0101]-[0102]) for the MEMS resonator (Fig. 12; [Abstract]).
Regarding claim 3, Saarela discloses the MEMS resonator of claim 1, wherein an average impurity doping of either the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) or the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) or both the first layer (Fig. 12, L1; [0100]) and the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) is 2*1019cm-3 or more (Fig. 12; [0012]).
Regarding claim 4, Saarela discloses the MEMS resonator of claim 1, wherein a <100> crystalline direction (Fig. 12; [0012]) in the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) is in a plane (Fig. 12; [0012]) of the first layer of single-crystalline silicon (Fig. 12, L1; [0100]), or deviates less than 10 degrees therefrom (Fig. 12; [0012]), and a <100> crystalline direction (Fig. 12; [0012]) in the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) is in a plane (Fig. 12; [0012]) of the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]), or deviates less than 10 degrees therefrom (Fig. 12; [0012]).
Regarding claim 5, Saarela discloses the MEMS resonator of claim 1, wherein a <100> crystalline direction (Fig. 12; [0012]) in the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) is parallel with (Fig. 12; [0012]), or deviates less than 10 degrees from (Fig. 12; [0012]), a <100> crystalline direction (Fig. 12; [0012]) in the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]).
Regarding claim 6, Saarela discloses the MEMS resonator of claim 1, wherein the crystalline directions (Fig. 12; [0012]) in the first single-crystalline silicon layer (Fig. 12, L1; [0100]) and in the second single-crystalline silicon layer (Fig. 12, L3-L4; [0102]) are parallel (Fig. 12; [0012]) or deviate at most 10 degrees (Fig. 12; [0012]).
Regarding claim 7, Saarela discloses the MEMS resonator of claim 1, wherein the temperature coefficient (Fig. 12; [0110]; [0112]) of the resonance frequency (Fig. 12; [0110]; [0112]) of either the first layer (Fig. 12, L1; [0100]) or the second layer of single-crystalline silicon layer (Fig. 12, L3-L4; [0102]) is positive (Fig. 12; [0112]).
Regarding claim 8, Saarela discloses the MEMS resonator of claim 1, wherein the crystalline c-axis of the piezoelectric layer (Fig. 12, L2; [0099]) is either parallel (Fig. 12; [0012]) to the direction orthogonal (Fig. 12; [0012]) to the plane (Fig. 12; [0012]) defined by (Fig. 12; [0012]) the piezoelectric layer (Fig. 12, L2; [0099]) or at an angle larger than zero (Fig. 12; [0012]) and smaller than 90 degrees (Fig. 12; [0012]) with respect to (Fig. 12; [0012]) the direction orthogonal (Fig. 12; [0012]) to said plane (Fig. 12; [0012]).
Regarding claim 9, Saarela discloses the MEMS resonator of claim 1, wherein the resonance mode (Fig. 12; [0019]) of the MEMS resonator (Fig. 12) is an in-plane resonance mode (Fig. 12; [0019]) and the thickness of the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) and the thickness (Fig. 12; [0100]-[0102]) of the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) are equal within 20% or less (Fig. 12; [0100]-[0102]).
Regarding claim 12, Saarela discloses the MEMS resonator of claim 1, wherein the resonance mode (Fig. 12; [0019]) of the MEMS resonator (Fig. 12) is a length-extensional mode resonance (Fig. 12; [0024]; [0051] [0089]).
Regarding claim 11, Saarela discloses the MEMS resonator of claim 1, wherein the resonance mode (Fig. 12; [0019]) of the MEMS resonator (Fig. 12) is an out-of-plane flexural mode (Fig. 12; [0019]) and the thickness (Fig. 12; [0100]-[0102]) of the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) substantially differs (Fig. 12; [0100]-[0102]) from the thickness (Fig. 12; [0100]-[0102]) of the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]), for example, at least by 20% or at least by 50% (Fig. 12; [0100]-[0102]).
Regarding claim 12, Saarela discloses the MEMS resonator of claim 1, comprising a release trench (Fig. 12; [0090]; [0103]) surrounding (Fig. 12; [0090]; [0103]) the resonator (Fig. 12) and extending through (Fig. 12; [0090]; [0103]) all material layers (Fig. 12; [0090]; [0103]) of the resonator (Fig. 12).
Regarding claim 13, Saarela discloses the MEMS resonator of claim 1, comprising an interconnection (Figs. 8/12, 120; [0106]) providing an electrical path (Figs. 8/12, 120; [0106]) to the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) through an opening (Figs. 8/12, 120; [0106]) in the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) and in the piezoelectric layer (Fig. 12, L2; [0099]).
Regarding claim 14, Saarela discloses the MEMS resonator of claim 1, comprising an intermediate material layer (Fig. 12, L4’; [0111]) between the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) and the piezoelectric layer (Fig. 12, L2; [0099]) or between (Fig. 12, L4’; [0111]) the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) and the piezoelectric layer (Fig. 12, L2; [0099]).
Regarding claim 15, Saarela discloses the MEMS resonator of claim 1, comprising an additional material layer (Fig. 12, L5) on a bottom surface (Fig. 12, bottom surface of L3-L4; [0102]) of the second layer of single-crystalline silicon (Fig. 12, L3-L4; [0102]) said additional material layer (Fig. 12, L5) facing (Fig. 12) a cavity (Fig. 12, cavity in L5) that separates (Fig. 12) the MEMS resonator (Fig. 12) from a substrate (Fig. 12, L6).
Regarding claim 16, Saarela discloses the MEMS resonator of claim 1, comprising a vertical trench (Figs. 8/12, 120) extending from end to end (Figs. 8/12, 120) of the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) and vertically through (Figs. 8/12, 120) the whole (Figs. 8/12, 120) first layer of single-crystalline silicon (Fig. 12, L1; [0100]) said vertical trench (Figs. 8/12, 120) electrically isolating (Figs. 8/12, 120) two regions (Fig. 12, two regions of L1; [0100]) of the first layer of single-crystalline silicon (Fig. 12, L1; [0100]).
Regarding claim 17, Saarela discloses the MEMS resonator of claim 1, comprising finetuning material layers (Fig. 12, L7-L8; [0108]) on top (Fig. 12) of the first layer of single-crystalline silicon (Fig. 12, L1; [0100]) for resonance frequency trimming (Fig. 12, L7-L8; [0107]-[0108]).
Conclusion
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

30 May 2026

/EMILY P PHAM/Primary Examiner, Art Unit 2837

Prosecution Timeline

• Dec 19, 2022: Application Filed
• Jun 03, 2026: Non-Final Rejection mailed — §102, §112 (current)