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, claims 1-16, in the reply filed on 10/17/2025 is acknowledged.
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.
Claims 1-3, 11, 13, and 15-16 are rejected under 35 U.S.C. 102(a)(1)/(a)(2) as being anticipated by Hennessy et al. (“Atomic layer deposition and etching methods for far ultraviolet aluminum mirrors”, Proceedings of SPIE Volume 10401-41, September 21, 2017), as submitted by Applicant on 06/13/2024.
As to claim 1, Hennessy discloses a method of making an enhanced aluminium mirror for vacuum ultraviolet (VUV) optics, the method comprising:
depositing a reflective coating comprising aluminium metal to at least one surface of a substrate through physical vapor deposition (PVD) in a PVD system to produce a mirror comprising the substrate and the reflective coating [“3. Atomic Layer Etching”, para. 1, “protective ALD coatings on PVD Al”];
removing aluminium oxides from an outer surface of the reflective coating [“3. Atomic Layer Etching”, para. 5, “exposes the PVD Al to approximately five minutes of cleanroom air (40% RH) prior to ALD encapsulation”] by conducting atomic layer etching (ALE) in an atomic layer deposition (ALD) system to produce an etched surface of the reflective coating [“3. Atomic Layer Etching”, para. 3, “alternating cycles of trimethylaluminum and HF can result in etching of Al2O3”]; and
depositing an ALD protective layer onto the etched surface of the reflective coating by conducting atomic layer deposition in the ALD system to produce the enhanced aluminium mirror comprising the substrate [“3. Atomic Layer Etching”, para. 3, “at lower temperatures the deposition of AlF3 begins to dominate for the same exposures”], the reflective coating deposited on the substrate, and the ALD protective layer covering the etched surface of the reflective coating [“process that can effectively strip the native oxide from an Al film, and replace it with a deposited layer of AlF3”]
As to claim 2, Hennessy discloses the method of claim 1, further comprising transferring the substrate comprising the reflective coating from the PVD system to the ALD system, wherein transferring the substrate having the reflective coating to the ALD system exposes the reflective coating to oxygen resulting in oxidation of aluminium at an outer surface of the reflective coating to form aluminium oxides [“3. Atomic Layer Etching”, para. 5, “exposes the PVD Al to approximately five minutes of cleanroom air (40% RH) prior to ALD encapsulation”].
As to claim 3, Hennessy discloses the method of claim 1, wherein the atomic layer etching in the ALD system comprises exposing the substrate and the reflective coating to alternating pulses of a fluorine source and an organometallic compound [“3. Atomic Layer Etching”, para. 3, “exposure to alternating cycles of trimethylaluminum and HF”], wherein:
exposing the substrate and reflective coating to a pulse comprising the fluorine source converts the aluminium oxides to aluminium fluoride to form a thin layer of aluminium fluoride on the outer surface of the reflective coating [“3. Atomic Layer Etching”, para. 3]; and
exposing the thin layer of aluminium fluoride to a pulse comprising the organometallic compound causes the aluminium fluoride to react to form a volatile organometallic compound that is released from the outer surface of the reflective coating [“3. Atomic Layer Etching”, para. 3].
As to claim 11, Hennessy discloses the method of claim 1, wherein:
the ALD protective layer comprises a metal fluoride protective coating comprising one or more of aluminium trifluoride (AlF3) [“3. Atomic Layer Etching”, para. 3], magnesium fluoride (MgF2), calcium fluoride (CaF2), lithium fluoride (LiF), lanthanum fluoride (LaF3), gadolinium fluoride (GdF3), or combinations of these; and
applying the protective ALD coating on the outer surface of the etched aluminium layer comprises exposing the etched aluminium layer to alternating pulses of a metal precursor and a fluorine source [“3. Atomic Layer Etching”, para. 3].
As to claim 13, Hennessy discloses the method of claim 11, wherein the metal precursor comprises an aluminium precursor selected from one or more of trimethylaluminium (TMA) [“3. Atomic Layer Etching”, para. 3], triethylaluminium (TEA), dimethylaluminium isopropoxide (DMAI), [MeC(NiPr)2]AlEt2, dimethylaluminiumhydride, dimethylethylamine, ethylpiperidine, dimethylaluminium hydride, or combinations of these.
As to claim 15, Hennessy discloses the method of claim 1, comprising: depositing a first ALD protective layer on the etched surface of the reflective coating [“3. Atomic Layer Etching”, para. 3]; and depositing a second ALD protective layer on an outer surface of the first ALD protective layer [“3. Atomic Layer Etching”, para. 3].
As to claim 16, Hennessy discloses the method of claim 1, where the ALD protective layer comprises a high reflective index metal fluoride [“3. Atomic Layer Etching”, para. 3], wherein the high reflective index metal fluoride increases the reflectance of the enhanced aluminium mirror relative to a mirror comprising only the reflective coating [“3. Atomic Layer Etching”, para. 4; Fig. 3].
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.
Claims 4-10 and 12 rejected under 35 U.S.C. 103 as being unpatentable over Hennessy et al. (“Atomic layer deposition and etching methods for far ultraviolet aluminum mirrors”, Proceedings of SPIE, September 21, 2017), as applied to claims 1-3, 11, 13, and 15-16 above, , in view of Vos et al. (“Atomic layer deposition of aluminum fluoride using AL(CH3)3 and Sf6 plasma”, Appl. Phys. Lett. 111, 113105, 2017).
As to claim 4, Hennessey discloses the method of claim 3, but fails to explicitly disclose the method further comprising:
exposing the reflective coating to alternating pulses of the fluorine source and the organometallic compound at a temperature of from 150 °C to 325 °C and an ICP power of from 50 Watts (W) to 600 W.
However, Vos et al. discloses a method of atomic layer deposition of aluminum fluoride using alternating steps of trimethylaluminum and sulfur hexafluoride plasma as an effective alternative to using hydrogen fluoride as a co-reactant [Abstract], the method employing inductively coupled sulfur hexafluoride plasma [pg. 1131105-1, para. 4], a deposition temperature of 200 degrees Celsius, a trimethylaluminum dose of 80 ms, a purge of 6s, a plasma exposure of 10s, and a final purge step of 4 s [pg. 1131105-2, para. 2]. Additionally, the “Supplementary material” of Vos further specifies the experimental details: “FlexALTM reactor is equipped with an inductively coupled plasma (ICP) source, operated at a radiofrequency of 13.56 MHz and typically a power of 300W. The TMA precursor (Sigma Aldrich, >99.9999%) was contained in a stainless steel bubbler, kept at a temperature of 30 °C. The precursor line was heated to 60 °C to avoid condensation of the precursor. The chamber pressure was set to 15 mTorr and 50 mTorr during the TMA dose and SF6 plasma exposure, respectively. During the ALD cycle 100 sccm SF6 gas was continuously injected from the top of the ICP source.” [“Supplementary material”, para. 1].
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of forming an aluminum fluoride coating by ALD using HF as a co-reactant, of Hennessey, to include a plasma-assisted deposition of an aluminum fluoride coating using sulfur hexafluoride plasma as a co-reactant and the conditions thereof, of Vos, in order to form a high-purity aluminum fluoride coating, and because it is an effective alternative to the HF co-reactant ALD process of Hennessey, as taught by Vos et al. [Abstract].
As to claim 5, modified Hennessey discloses the method of claim 3, further comprising exposing the etched surface of the reflective coating to the fluorine source for an exposure time of from 1 second to 60 seconds [Vos, pg. 1131105-2, para. 2].
As to claim 6, modified Hennessey discloses the method of claim 3, wherein the fluorine source comprises SF6, SF6 plasma [Vos, Abstract], or a plasma comprising SF and argon (Ar), and the organometallic compound comprises trimethylaluminium (TMA) [Vis, abstract], triethylaluminium (TEA), dimethylaluminium chloride (DMAC), silicon tetrachloride (SiCl4), aluminium hexafluoroacetylacetonate (Al(hfac)3), tri-1-butylaluminium (Al(iBu)3), tin(II)acetylacetonate (Sn(acac)2), tris(2,2,6,6-tetramethyl-3,5-heptanedionato)aluminium (i.e., Al(TMHD)3), or combinations of these.
As to claim 7, modified Hennessey discloses the method of claim 3, further comprising exposing the thin layer of aluminium fluoride to the organometallic compound for a total exposure time of from 10 milliseconds (ms) to 60,000 ms, where the total exposure time is equal to a pulse length of the pulse of the organometallic compound and a shut-in period [pg. 1131105-2, para. 2].
As to claim 8, modified Hennessey discloses the method of claim 3, further comprising exposing the thin layer of aluminium fluoride to the organometallic compound at a pressure of from 10 millitorr (1.33 Pa) to 100 torr (13,332 Pa) [Vos, “Supplemental Material”, para. 1, “The chamber pressure was set to 15 mTorr and 50 mTorr during the TMA dose and SF6 plasma exposure, respectively”].
As to claim 9, modified Hennessey discloses the method of claim 3, wherein exposing the thin layer of aluminium fluoride to the pulse comprising the organometallic compound comprises:
injecting the organometallic compound into the ALD chamber for a pulse length [Vos, “Supplementary material”, para. 1; Vos, pg. 1131105-2, para. 2]; and
closing a throttle valve of the ALD system, wherein closing the throttle valve prevents flow of materials into or out of the ALD chamber and maintains the thin layer of aluminium fluoride in contact with the organometallic compound for a shut in period of from 1 second to 60 seconds [Vos, “Supplementary material”, para. 1; Vos, pg. 1131105-2, para. 2].
As to claim 10, modified Hennessey discloses the method of claim 9, further comprising:
reopening the throttle valve [Vos, “Supplementary material”, para. 1; Vos, pg. 1131105-2, para. 2]; and
purging the ALD chamber with an inert gas to remove at least 99% of the residual organometallic compounds, the volatile organometallic compounds, or both from the ALD chamber [Vos, pg. 1131105-2, para. 2].
As to claim 12, Hennessey discloses the method of claim 11, but fails to explicitly disclose:
wherein the fluorine source comprises SF, an SF6 plasma, or a plasma comprising SF6 and argon (Ar).
However, Vos et al. discloses a method of atomic layer deposition of aluminum fluoride using alternating steps of trimethylaluminum and sulfur hexafluoride plasma as an effective alternative to using hydrogen fluoride as a co-reactant [Abstract], the method employing inductively coupled sulfur hexafluoride plasma [pg. 1131105-1, para. 4], a deposition temperature of 200 degrees Celsius, a trimethylaluminum dose of 80 ms, a purge of 6s, a plasma exposure of 10s, and a final purge step of 4 s [pg. 1131105-2, para. 2].
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of forming an aluminum fluoride coating by ALD using HF as a co-reactant, of Hennessey, to include a plasma-assisted deposition of an aluminum fluoride coating using sulfur hexafluoride plasma as a co-reactant, of Vos, in order to form a high-purity aluminum fluoride coating, and because it is an effective alternative to the HF co-reactant ALD process of Hennessey, as taught by Vos et al. [Abstract].
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Hennessy et al. (“Atomic layer deposition and etching methods for far ultraviolet aluminum mirrors”, Proceedings of SPIE, September 21, 2017), as applied to claims 1-3, 11, 13, and 15-16 above, , in view of Balasubramanan, Proceedings of SPIE Volume 10398-13, 2017).
As to claim 14, Hennessy discloses the method of claim 11, but fails to explicitly disclose:
wherein the ALD protective layer comprises magnesium fluoride (MgF2).
However, Balasubramanan teaches the atomic layer etching of surface oxide on aluminum combined with atomic layer deposition may be applied to form MgF2 protective overcoats in forming a stable aluminum mirror [pg. 8, “Atomic Layer Etching (ALE) to remove surface oxide”].
Therefore, it would have been prima facie obvious to one of ordinary skill int eh art before the effective filing date of the claimed invention to modify the method of forming an aluminum fluoride coating by ALE/ALD process, of Hennessy, to form a magnesium fluoride coating by ALE/ALD process, of Balasubramanan, in order to form a stable aluminum mirror, a taught by Balasubramanian [pg. 8, “Atomic Layer Etching (ALE) to remove surface oxide”].
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: The additionally cited references are cited to show methods of forming aluminum fluoride coatings and/or methods combining ALE and ALD processes [Abstracts].
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/CHRISTOPHER REMAVEGE/Examiner, Art Unit 1713