Prosecution Insights
Last updated: April 19, 2026
Application No. 18/039,474

METHOD AND SYSTEM FOR FABRICATING TWO-DIMENSIONAL MATERIAL BY USING GAS-PHASE METHOD

Non-Final OA §103
Filed
May 30, 2023
Examiner
PIRO, NICHOLAS ANTHONY
Art Unit
1738
Tech Center
1700 — Chemical & Materials Engineering
Assignee
BEIHANG UNIVERSITY
OA Round
1 (Non-Final)
42%
Grant Probability
Moderate
1-2
OA Rounds
3y 4m
To Grant
52%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
8 granted / 19 resolved
-22.9% vs TC avg
Moderate +10% lift
Without
With
+10.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
68 currently pending
Career history
87
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
43.4%
+3.4% vs TC avg
§102
15.0%
-25.0% vs TC avg
§112
23.3%
-16.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 19 resolved cases

Office Action

§103
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 . 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. Election/Restrictions Applicant's election with traverse of Group I, claims 1 and 4-16 in the reply filed on 14 January 2026 is acknowledged. The traversal is on the grounds that the technical features of "a reaction of a gas having an etching effect with a MAX phase material at a predetermined temperature to obtain a two-dimensional material containing MX," and "wherein the gas having the etching effect comprises at least one selected from the group of a halogen elementary substance, a halogen hydride, and a nitrogen-family hydride, wherein the halogen elementary substance is Br2; the halogen hydride is HC, HBr or HI; and the nitrogen-family hydride is NH3 or H3P" is shared by claims 1, 17, and 22. This is not found persuasive because while claim 17 is drawn to a system (apparatus) which requires a reaction device configured for a reaction of a gas having an etching effect with a MAX phase material at a predetermined temperature to obtain a two-dimensional material containing MX; as well as a first gas device, configured for introducing the gas having the etching effect into the reaction device, wherein the gas having the etching effect comprises at least one selected from the group of a halogen elementary substance, a halogen hydride, and a nitrogen-family hydride, wherein the halogen elementary substance is Br2; the halogen hydride is HCl, HBr or HI; and the nitrogen-family hydride is NH3 or H3P, the actual performing of such a reaction is not a requirement of the apparatus itself. Therefore, an apparatus which requires a first gas device configured for introducing Br2, HCl, HBr, HI, NH3, or PH3 can be considered an obvious variation of the device disclosed by Hoffman et al., which is configured to introduce Cl2. One of ordinary skill in the art would find it obvious to modify such a device to carry out a reaction that requires any of these different gases but otherwise similar reaction conditions by simply exchanging the gas source. For example, one of ordinary skill in the art would have been motivated to replace the chlorine source used in the apparatus of Hoffman (p. 2317, col. 2, ¶ 5) with an ammonia source in order to carry out the reaction described by Urbankowski et al. (Nanoscale 2017, 9, 17722), which takes place in a similar apparatus (a quartz tube furnace), on similar materials (MAX phase and MXene materials), and at similar temperatures (400-800 °C). Therefore the apparatuses described by each of Hofmann and Urbankowski can be described as “configured for” the purposes recited in the instant claim, or obvious variations of such an apparatus, and so the shared technical feature does not make a contribution over the prior art and unity of invention is lacking. The requirement is still deemed proper and is therefore made FINAL. Claims 17-22 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 14 January 2026. Claim and Specification Objections Claims 9 and 15, and specification paragraph [0020] recite “the hydride of the fourth main group is CH4, C2H8, C2H4, H4Ge or H4Si.” C2H8 is not a known substance. However, one of ordinary skill in the art would recognize this as a typographical error and presume that the intended substance was ethane, C2H6. Appropriate correction to the claims and specification are required. 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, 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 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. 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, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1). Regarding claim 1, Shin teaches a method for fabricating a two-dimensional material (MXene nanosheet; abstract) by using gas phase method, the method comprising: a gas phase etching step, wherein a gas having an etching effect reacts with a MAX phase material at a first predetermined temperature to etch an A component from the MAX phase material, and a two-dimensional material containing MX is obtained (the A atomic layer is first selectively removed from the MAX phase to obtain a nanosheet …Removing the A atomic layer may be performed under acidic conditions…The acid may be in a gas phase; [0053]-[0060]), wherein the gas having the etching effect comprises a halogen hydride, the halogen hydride being HCl (The acid may be, for example, a relatively strong acid containing a fluorine atom…these fluorine containing compounds may be mixed with a strong acid, e.g. hydrochloric acid; [0059]). Though Shin does not teach a single embodiment with a gas phase etchant comprising HCl, Shin teaches both that the acid may comprise HCl and that the acid may be in the gas phase. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to perform the method using a gas phase etchant comprising HCl. One of ordinary skill in the art would have been motivated to do so because they would simply be combining two features of the etchant described by Shin. Regarding claim 4, Shin teaches the method of claim 1, where the first predetermined temperature is in the range of about 20 °C to about 800 °C ([0060]), which overlaps with the instantly claimed range of from 500 °C to 1200 °C. It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, the claimed ranges merely represent an obvious variant and/or routine optimization of the values of the cited prior art. Regarding claim 16, Shin teaches the method of claim 1 where the MAX phase material may be Ti2AlC, in which M is titanium, a transition element; A is aluminum, a main group element; and X is carbon ([0048]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Ti2AlC as the MAX phase material. One of ordinary skill in the art would have been motivated to do so because Shin teaches that this is a suitable substrate on which to apply their method and because the MXene derived from Ti2AlC have a broad range of applications ([0008]). Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1), as applied to claim 1, and further in view Hassan et al. (US 2008/0102640 A1). Regarding claim 5, Shin teaches the method of claim 1, but does not teach the gas comprising a carrier gas. However, like Shin, Hassan teaches etching using gas phase halogenated hydrogen-containing gas, such as HF and HCl, ([0016]) and Hassan further teaches the etchant gas comprising a carrier gas which may be nitrogen ([0017]), and that such a carrier gas can be used to carry or transport the reactive etchant gases. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the method of Shin an etchant comprising nitrogen as a carrier gas, as taught by Hassan. One of ordinary skill in the art would have been motivated to do so because Hassan teaches that such constituents can be used to help transport the reactive gases. Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1), as applied to claim 1, and further in view of Ullmann’s Encyclopedia of Industrial Chemistry (Austin, S. and Glowacki, A. (2000). Hydrochloric Acid. In Ullmann's Encyclopedia of Industrial Chemistry, DOI: 10.1002/14356007.a13_283). Regarding claims 6 and 7, Shin teaches the method of claim 1, but does not teach any method for producing the gas having the etching effect. However, Ulmann teaches that that HCl can be produced by the reaction of sulfuric acid with sodium chloride, a halogen metal salt (p. 196, Section 3.1 and 3.2.2). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the method of Shin HCl gas that is produced by the reaction of sulfuric acid with sodium chloride, as taught by Ulmann, thereby meeting the limitations of claims 6 and 7. In doing so, one would be combining the known method of generating HCl taught by Ulmann with the known process of Shin that requires a source of HCl to yield predictable results. MPEP 2143(I)(A). Claims 8-11 and 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1), as applied to claim 1, and further in view of Barsoum et al. (US 2014/0162130 A1) and Farag (Energy & Fuels 2002, 16, 944-950). Regarding claims 8 and 9, Shin teaches the method of claim 1, but does not teach an adjustment step wherein the two-dimensional material containing MX reacts with a functional gas that is an elemental substance or a hydride of the fourth, fifth, or sixth main groups. However, Barsoum also teaches the production of two-dimensional materials containing MX from MAX phase materials ([0006]-[0009] and [0025]), and Barsoum further teaches an adjustment step where the two-dimensional material is functionalized (the ability to functionalize the surfaces of the layers of the present invention to provide enrichment of a particular functional group provides a considerable synthetic and structural flexibility… an originally presented M-hydroxide surface may be converted to oxide or sub-oxide surface by application of heat or other dehydrating conditions. Nitrogen and sulfur surfaces may be analogously interconverted by methods known in the art for making such conversions; [0102] and [0106]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply an adjustment step to the method of Shin, as taught by Barsoum. In particular, one would have been motivated to create a sulfur-functionalized surface because Barsoum suggests doing so. Barsoum does not teach a method to add the sulfur functionalization and only suggests doing so by methods known in the art. One of ordinary skill would therefore turn to the art to find such a method of interchanging an oxygen for a sulfur. Farag teaches such a method for interchanging an oxide for a sulfur surface, as suggested by Barsoum. The method of Farag includes the use of hydrogen sulfide gas at a predetermined temperature and results in a material containing sulfur, an element of the sixth main group (p. 948, Eq. 4-6). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the method of Shin an adjustment step wherein the two-dimensional material containing MX reacts with hydrogen sulfide (H2S), a functional gas that is a hydride of the sixth main group, at a predetermined temperature to result in a two-dimensional material containing sulfur, an element of the sixth main group, as taught by Farag. One of ordinary skill in the art would have been motivated to do so because Barsoum suggests carrying out this transformation using a method known in the art, and Farag provides one such method. Regarding claim 10, modified Shin teaches the method of claim 8, where Barsoum teaches replacing part or all of functional groups of the two dimensional material containing MX to obtain a two-dimensional material containing a functional group of sulfur, an element of the sixth main group (an originally presented M-hydroxide surface may be converted to oxide or sub-oxide surface by application of heat or other dehydrating conditions. Nitrogen and sulfur surfaces may be analogously interconverted by methods known in the art for making such conversions; [0106]). Regarding claims 11 and 13, modified Shin teaches the method of claim 9, where Farag teaches the conversion of oxides to sulfides can be carried out at 600 °C (p. 948, Eq. 4), which falls in the instantly claimed ranges of both claims 11 and 13. It is also noted that Farag further discusses the temperatures required, and relates the high temperatures required to the bulk crystalline, non-porous form of the materials being converted (MoO2 is so resistant to sulfiding by 5 wt%H2S/H2 gas mixture until reaching a very high temperature of ca. 800 °C. Probably the formed texture of MoO2 is not very porous, so diffusion limitations of 5 wt% H2S/H2 gas mixture are being concerned. This could be supported by the surface black color of such material that is very probably due to the sulfiding of minor amounts of surface species. Both MoO3 and MoO2 are formed in highly crystalline form; p. 198, col. 2, ¶ 1). Because Shin teaches that there materials have highly exposed surfaces (e.g., Fig. 11B), one of ordinary skill in the art would recognize based on Farag’s analysis that the high temperatures used by Farag may not be required. It therefore would have been obvious to optimize by routine experimentation the predetermined temperature used in the adjustment step. It is further noted that, generally, differences temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." See MPEP 2144.05 and In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Regarding claims 14 and 15, Shin teaches the method of claim 1, but does not teach providing a functional gas that is an elemental substance or a hydride of the fourth, fifth, or sixth main groups in the etching step to produce a material containing an element of the fourth, fifth, or sixth main groups. However, Barsoum also teaches the production of two-dimensional materials containing MX from MAX phase materials ([0006]-[0009] and [0025]), and Barsoum further that these materials can be functionalized by methods known in the art for exchanging surface groups (the ability to functionalize the surfaces of the layers of the present invention to provide enrichment of a particular functional group provides a considerable synthetic and structural flexibility… The skilled artisan will be able to interchange the pendant groups by methods known in the art…an originally presented M-hydroxide surface may be converted to oxide or sub-oxide surface by application of heat or other dehydrating conditions. Nitrogen and sulfur surfaces may be analogously interconverted by methods known in the art for making such conversions; [0102] and [0106]). Barsoum does not teach a specific method to add the sulfur functionalization but rather suggests doing so by methods known in the art (The skilled artisan will be able to interchange the pendant groups by methods known in the art; [0106]). One of ordinary skill would therefore turn to the art to find such a method of interchanging an oxygen for a sulfur, as suggested by Barsoum. Farag teaches one such a method for interchanging an oxide for a sulfur surface. The method of Farag includes the use of hydrogen sulfide gas at a predetermined temperature and results in a material containing sulfur, an element of the sixth main group (p. 948, Eq. 4-6). Regarding whether this functionalization is performed during or after the etching step, it is noted that the courts have held that any order of performing process steps is prima facie obvious in the absence of new or unexpected results (In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930); Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959)). See MPEP §2144.04 IV C. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide in the etching step taught by Shin the functional gas of hydrogen sulfide (H2S), a hydride of the sixth main group, so that the MAX phase material undergoes a gas phase etching reaction with the gas having the etching effect, as taught by Shin, and simultaneously the two-dimensional material containing MX and the functional gas undergo a functional-group adjustment reaction, as taught by Barsoum and Farag, wherein the gas phase etching step results in a two-dimensional material containing sulfur, an element of the sixth main group. One of ordinary skill in the art would have been motivated to do so because Barsoum teaches that it is appropriate to introduce sulfur by functional group interchange on the etched material and Farag teaches that H2S is a reagent than can carry out this transformation. One of ordinary skill would have been further motivated to carry out the two reactions in one step because doing so would add additional efficiency to the process. Claims 8-9 and 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1), as applied to claim 1, and further in view of Urbankowski et al. (Nanoscale 2017, 9, 17722). Regarding claims 8 and 9, Shin teaches the method of claim 1, but does not teach an adjustment step wherein the two-dimensional material containing MX reacts with a functional gas that is an elemental substance or a hydride of the fourth, fifth, or sixth main groups. However, Urbankowski teaches an adjustment step of two-dimensional MX containing materials as a method to synthesize nitride MXenes, wherein the two-dimensional material containing MX reacts with ammonia (NH3), a functional gas that is a hydride of the fifth main group, at a predetermined temperature and resulting in a two-dimensional material containing an element of the fifth main group (the first transformation of Mo2CTx and V2CTx carbide MXenes into 2D metal nitrides via ammoniation at 600 °C; p. 2, col. 1, ¶ 2 and Scheme 1). Urbankowski further teaches that this methos affords nitride MXenes where other methods have been unsuccessful, and that nitride MXenes have potential applications in energy storage and plasmonics (p. 1, col. 2, ¶ 2 and p. 2, col. 1, ¶ 2). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the adjustment step taught by Urbankowski to the products derived by the method of Shin. One of ordinary skill in the art would have been motivated to do so because this step can produce new materials with potential applications in energy storage and plasmonics, as taught by Urbankowski. Regarding claims 11 and 13, modified Shin teaches the method of claim 9, where Urbankowski teaches performing the ammoniation at 600 °C, which meets the limitations of claims 11 and 13 (the first transformation of Mo2CTx and V2CTx carbide MXenes into 2D metal nitrides via ammoniation at 600 °C; p. 2, col. 1, ¶ 2). Regarding claim 12, modified Shin teaches the method of claim 8, where Urbankowski teaches nitrogen, an element of the fifth main group, replacing all of the X component (carbon) in the two dimensional material containing MX and the adjustment step resulting in a two-dimensional material containing nitrogen (Scheme 1). Pertinent Prior Art The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure: US 2021/0139379 A1 (filed 30 September 2020) describes the etching of MAX phase materials under inert conditions with etchants comprising bromine, iodine, and mixed halogen etchants to produce a two-dimensional material. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally Merkling can be reached at (571) 272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738 /PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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Prosecution Timeline

May 30, 2023
Application Filed
Feb 18, 2026
Non-Final Rejection — §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
42%
Grant Probability
52%
With Interview (+10.0%)
3y 4m
Median Time to Grant
Low
PTA Risk
Based on 19 resolved cases by this examiner. Grant probability derived from career allow rate.

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