DETAILED ACTION
This is the Office action based on the 18395879 application filed December 26, 2023, and in response to applicant’s argument/remark filed on November 17, 2025. Claims 1-19 are currently pending and have been considered below. Applicant’s withdrawal of claim 19 acknowledged.
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 the invention of Group I, claims 1-18 in the reply filed on November 17, 2025 is acknowledged. Claim 19 withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention.
Applicant’s election, without traverse, of the invention of Species 1a and 2a in the reply filed on November 17, 2025 is acknowledged.
Claim Objections
Claim 5 objected to because of the following informalities: the term “tunsten halide” appears to contain a typographical error. For the purpose of examining it will be assumed that this term is “tungsten halide”. 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 3 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 inventor or a joint inventor regards as the invention. Claim 3 recites “(t)he etching method according to claim 2, wherein (b) is performed between (c) and (d)”. However, claim 2 recites “(t)he etching method according to claim 1, wherein… the etching method further comprises (d) after (c)”, and claim 1 recites “(c) after (b)”. One of skill in the art would not be clear how to perform (c) after (b), (d) after (c), and (b) between (c) and (d). For the purpose of examining it will be assumed that (b) is performed before (c) and (d).
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 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.
(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..
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 4-7 and 9-10 rejected under 35 U.S.C. 102(a)(1) and 35 U.S.C. 102(a)(2) as anticipated by Veber et al. (U.S. PGPub. No. 20230298896), hereinafter “Veber”.
--Claims 1, 4, 5, 6, 7: Veber teaches a method of etching (Fig. 2 and 4), comprising(i) forming a mask layer 106 having an opening over a layer to be etched 103 ([0025]), wherein layer 103 may comprise a plurality of layers, such as SiO2, SiN, SiON, SiOC, SiCN, etc. ([0031]). (ii) partially etching the layer 103 through the opening ([0049]), such as by using a plasma comprising fluorocarbon and/or hydrogen ([0052]);(iii) depositing a protective layer on the sidewall of the opening ([0057-0060]), wherein the protective layer may comprise W or Mo ([0061]) and may be formed by using a first plasma of a metal-containing gas, such as WF6 or MoF6, and a reducing agent, such as CH4 ([0064-0070]);(iv) etching the layer 103 by using a second plasma ([0080-0081]), and wherein an etchant chemistry of the second plasma may be different than an etchant chemistry of the first plasma ([0084]).(v) repeating steps (iii) and (iv) a plurality of times (Step 440 in Fig. 4).--Claim 9: It is noted that CH4 is a hydrocarbon gas--Claim 10: Veber further teaches that the second plasma may be generated from a fluorocarbon and a hydrogen-containing reactant ([0084]).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 8 and 12 rejected under 35 U.S.C. 103 as being obvious over Veber:--Claim 8: Veber teaches the invention as in claim 5 above. Veber further teaches that the first plasma may further comprise an inert gas and a fluorine-containing gas ([0069-0070]), and that the flow of the metal-containing gas may be about 0.1-20 sccm, the flow of the reducing gas may be about 10-500 sccm, the flow of the inert gas may be about 0-500 sccm, and the flow of the fluorine-containing gas may be about 0-500 sccm ([0071]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to flow the metal-containing gas at 10 vol.% or less than the total gas flow.--Claim 12: Veber teaches the invention as in claim 1 above. Veber further teaches that layer 103 comprising a silicon oxide layer sandwiched between two silicon nitride layers ([0031]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to form the layer 103 comprising a top silicon nitride layer, a middle silicon oxide layer, then a bottom silicon nitride layer.
Claims 2-3, 11 and 13-18 rejected under 35 U.S.C. 103 as being unpatentable over Veber as applied to claim 1 above, and further in view of Lian et al. (U.S. PGPub. No. 20230268235), hereinafter “Lian”:--Claims 2, 3: Veber teaches the invention, wherein an etching is performed to etch layer 103 comprising a plurality of different sub-layers, such as SiO2, SiN, SiON, SiOC, SiCN, etc., as shown above. Veber further teaches that layer 103 may comprise a silicon oxide layer sandwiched between two silicon nitride layers, or alternating layers of silicon oxide and silicon nitride ([0031]), that the second plasma may continue etching through the one or more layers of materials in step (iv), and that the etch may be selective to the one or more layers of materials and nonselective to the mask layer and the protective film ([0081]). Veber does not teach the claimed feature of etching a first sub-layer in the layer 103 by using a second plasma then etching a second sub-layer in the layer 103 by using a third plasma different than the second plasma. Lian, also directed to a method of etching a layer from a stack comprising different layers (Fig. 3A-B), teaches that the layer may be selectively etched by stopping the etching when an endpoint signal is detected that indicates the etching has exposed an underlying layer ([0004-0006, 0013-0014, 0024-0034, 0037-0040]) Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to (a) selectively etch a silicon nitride layer by using the second plasma wherein (b) the etching stops as soon as the silicon oxide layer is exposed, then (c) repeating the depositing a protective layer on the sidewall, then (d) selectively etch the silicon oxide layer by using a third plasma different than the second plasma because Veber teaches that the layer 103 may comprise a silicon oxide layer sandwiched between two silicon nitride layers, that the second plasma may etch one layer of material in step (iv), that the etching may be selective to the one layer of materials and nonselective to the mask layer and the protective film; and Lian teaches that a layer may be selectively etched with respect to an underlying layer by stopping the etching when an endpoint signal is detected that indicates the etching has exposed an underlying layer.--Claims 15, 16, 17, 18: Likewise, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to etch the layer 103 comprising a plurality of different layers, such as alternating layers of silicon oxide and silicon nitride, by repeating the steps (a)-(d) above.--Claim 11: Since the second plasma is different than the third plasma, and since Veber teaches that the second plasma comprises a hydrogen-containing reactant, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to use a third plasma that does not contain a hydrogen-containing reactant in the invention of Veber modified by Lian.--Claim 13: Veber further teaches that layer 103 comprising a silicon oxide layer sandwiched between two silicon nitride layers ([0031]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to form the layer 103 comprising a top silicon nitride layer, a middle silicon oxide layer, then a bottom silicon nitride layer.--Claim 14: Veber further teaches that each etching cycle may remove one layer or 10-2,000 nm ([0054]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to perform the etching on a layer 103 that comprises a silicon oxide layer sandwiched between two silicon nitride layers, or alternating layers of silicon oxide and silicon nitride, wherein each layer has a thickness of 10- 2,000 nm in the invention of Veber. It is noted that this overlaps the claimed range of 100 nm or more.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to THOMAS PHAM whose telephone number is (571) 270-7670 and fax number is (571) 270-8670. The examiner can normally be reached on MTWThF9to6 PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Allen can be reached on (571) 270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/THOMAS T PHAM/Primary Examiner, Art Unit 1713