DETAILED 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 .
Election/Restrictions
Applicant’s election without traverse of Group I in the reply filed on May 19, 2026, is acknowledged.
Claim Rejections - 35 USC § 102
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 (i.e., changing from AIA to pre-AIA ) 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.
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.
Claims 1-2, 5-10 and 12-19 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wu et al (US 2022/0375762 A1), as evidenced by Wang et al (US 2022/0301857 A1).
Wu discloses a substrate-processing method (abstract), comprising:
providing a substrate including a silicon oxide film 11 on a surface of the substrate (“to-be-processed wafer” [0041], Fig. 1);
supplying a first gas to the surface of the substrate, the first gas containing a hydrogen fluoride gas and containing no basic gas (during the “etching process” [0044], during the time that HF is continuously supplied [0085] and NH3, a basic gas, is not supplied, when the NH3 is pulsed off, times that are “in absence of NH3 catalyst” [0085]);
after (b), supplying a second gas to the surface of the substrate, the second gas containing both a hydrogen fluoride gas and a basic gas (during the “etching process” [0044], during the times that HF is continuously applied and the NH3 gas is pulsed on [0085]).
Wu discloses etching with HF continuously supplied, but pulsing NH3, which reads on steps b and c.
As to amended claim 1, Wu fails to disclose the composition of the “byproducts” that are formed during the etching step (“byproducts deposited on the silicon oxide film partially prevent the etching gas from directly reacting with the SiO2 in contact, and slow down the etching rate of SiO2.” [0086]). Wang is applied as evidence to show that the etching byproducts are the cited silicon tetrafluoride and ammonium silicofluoride. More specifically, Wang teaches that silicon tetrafluoride forms when silicon oxide and HF react [0050] and ammonium silicofluoride forms when HF and ammonia gas react with silicon oxide [0048] , e.g., under conditions of no plasma [0051]. Because Wu conducts the same steps as in the instant invention, the same results are expected, inherently, as evidenced by Wang.
As to claim 2, see the rejection of claim 1, HF is continuously supplied [0085].
As to claim 5, Wu discloses that the etching process, i.e., steps b and c, are conducted at 120 °C [0017], which is a same temperature as cited.
As to claim 6, Wu discloses to supply the second gas along the surface of the substrate (as depicted in Figure 7).
As to claim 7, Wu discloses the same steps as are conducted as in the instant invention, and therefore the same results are expected.
As to claim 8, Wu discloses to provide a basic gas of ammonia gas (see rejection of claim 1).
As to claims 9-10, 12-16, Wu discloses (d) after (c), heat-treating the substrate at a temperature higher than in (c) (sublimation at 180 °C [0019], [0089], [0096]).
As to claim 18, Wu discloses a cooling step (S150, 240, Figure 5) and exposing to room temperature [0088], which is within the cited range during steps b) and c).
As to claim 19, Wu discloses that substrate further includes a silicon nitride film [0041] (Fig. 1), that is etched without a surface modification layer 13 formed on the SiN (Table 1 [0042]- [0043]), which encompasses removing native oxide that is inherently present or native to the SiN surface.
Claims 1-2, 5-10 and 12-16 are rejected under 35 U.S.C. 102(a)(1) as being clearly anticipated by Wang et al (US 2022/0301857 A1).
Wang discloses a substrate-processing method (abstract), comprising:
providing a substrate including a silicon oxide film 11 on a surface of the substrate (210, Fig. 1);
supplying a first gas to the surface of the substrate, the first gas containing a hydrogen fluoride gas and containing no basic gas (240, Fig. 1);
after (b), supplying a second gas to the surface of the substrate, the second gas containing both a hydrogen fluoride gas and a basic gas (cycling 260 such that step 220 is after step 240, Fig. 1),
wherein (b) includes reacting the silicon oxide film and the hydrogen fluoride gas, thereby forming silicon tetrafluoride [0050], and (c) includes reacting the silicon tetrafluoride, the hydrogen fluoride gas, and the basic gas, thereby forming ammonium silicofluoride [0048].
As to claim 2, Wang discloses performing (c) successively as cited (cycling 260, Fig. 1).
As to claim 5, Wang fails to disclose change the temperature, therefore it is expected to be maintained at the same temperature.
As to claim 6, Wang discloses to supply the second gas along the surface of the substrate (as depicted in Figures 5A-5D).
As to claim 7, Wang discloses the same steps as are conducted as in the instant invention, and therefore the same results are expected.
As to claim 8, Wang discloses to provide a basic gas of ammonia gas [0039].
As to claims 9-10, 12-16, Wang discloses subliming, which encompasses the cited higher temperature for heat-treating [0054].
Claim Rejections - 35 USC § 103
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 (i.e., changing from AIA to pre-AIA ) 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.
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, 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.
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 3 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al (US 2022/0375762 A1), as evidenced by Wang et al (US 2022/0301857 A1).
The discussion of Wu from above is repeated here.
As to claim 3, Wu fails to disclose the duration of (b) compared to (c). Wu teaches that process parameters can be optimized [0085]. The amount of time that an etching species is present is a parameter that can be optimized for best results of etching. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to provide the cited times in the method of Wu in order to optimize the times for etching to produce the best results.
As to claim 11, Wu discloses (d) after (c), heat-treating the substrate at a temperature higher than in (c) (sublimation at 180 °C [0019], [0089], [0096]).
Response to Amendment
Claims 1-2, 5-10 and 12-19 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wu et al (US 2022/0375762 A1), as evidenced by Wang et al (US 2022/0301857 A1).
Claims 3 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al (US 2022/0375762 A1), as evidenced by Wang et al (US 2022/0301857 A1).
Claims 1-2, 5-10 and 12-16 are rejected under 35 U.S.C. 102(a)(1) as being clearly anticipated by Wang et al (US 2022/0301857 A1).
Wang is newly applied to show that the byproducts of the reaction between silicon oxide and the supplied gases are as cited in amended claim 1.
Response to Arguments
Applicant's arguments filed July 27, 2026, have been fully considered but they are not persuasive. Applicant argues that
In contrast, the purpose of pulsing the gases in Wu's process is merely to purge the etching gas and quickly remove the etching reactants and byproducts from the wafer surface (see para. [0055]). For example, Wu explicitly teaches that the objective of performing multiple cycles of etching is to "fully sublime and discharge the etching reactants and byproducts" (see para. [0086]).
In response, the byproducts that form on the wafer surface in the method of Wu are the same products as claimed, as evidenced by Wang. Applicant also pulses (claim 2) and sublimes (heat-treatment claims 9-15) to remove reaction byproducts. While there may be some purging in the method of Wu, Wu discloses that the silicon oxide is removed, i.e., etched. The etching is by forming byproducts and removing them. Wu uses the same gases and materials as in the instant invention, and therefore the same results are expected.
Applicant argues that Wu fails to “intentionally” pre-form silicon tetrafluoride. In response, prior art need not recognize the chemical composition of the byproducts formed in order to anticipate the claimed invention. As explained in the MPEP at section 2112, the claiming of a new use, new function or unknown property which is inherently present in the prior art does not necessarily make the claim patentable. In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977). Here, Wu may not recognize that the chemical composition of the reaction products of silicon oxide with HF and ammonia, but they are known as evidenced by Wang. Therefore, the argument that Wu must “intentionally” form the cited byproducts is not persuasive. The byproducts are formed, inherently, because the gases react with the silicon oxide to form byproducts.
The arguments relating to claims 18-19 are addressed above in the rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANITA K ALANKO whose telephone number is (571)270-0297. The examiner can normally be reached Monday-Friday, 9 am-5pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Allen can be reached at 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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/ANITA K ALANKO/ Primary Examiner, Art Unit 1713
