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 .
Response to Arguments
Applicant’s addition of claims 19-20 is acknowledged.
Applicant’s replacement drawings have overcome the objection to the drawings by removing the reference items not described within the specification.
Applicant's arguments filed 9 October 2025 have been fully considered but they are not persuasive.
Applicant has added two dependent claims but otherwise has not made amendments to the claims previously examined. Applicant argues that the previous rejection of independent claim 1 and its corresponding dependent claims made under 35 U.S.C. 103 as being unpatentable over Ehm et al. is improper due to not establishing a case of prima facie obviousness. In particular, Applicant argues that Ehm fails to teach a “glass material”, including an aluminosilicate glass or a borosilicate glass. The Examiner concedes that the disclosure of Ehm does not utilize the word “glass”. However, the components taught by Ehm, namely those recited on page 24, lines 19-25 of Ehm are understood to be “glass materials”. For instance, aluminum (Al) and boron (B), when formed as a silicate (which is suggested by Ehm in the aforementioned passage) are understood in the art to be glass materials. For instance, US 5320920 A, which is not relied upon to reject the claims but merely acts as an evidentiary reference to rebut the Applicant’s arguments, teaches a transparent substrate formed of glass, including aluminosilicate or boron silicate glasses (see Col. 2 Lines 30-36). Likewise, US 20140234755 A1, which is also not relied upon to reject the claims but merely acts as an evidentiary reference to rebut the Applicant’s arguments, teaches a mask blank substrate formed of quartz glass, borosilicate glass, or aluminosilicate glass (see paragraph 0051). The plain meaning of aluminosilicate and borosilicate in the art is understood to mean a “glass material”. The teaching of Ehm to include a silicate of aluminum or boron, amongst other elemental species, implies a glass material, even if Ehm does not utilize the term “glass” within the specification. There is no indication that the aluminum silicate or boron silicate suggested by Ehm is any different from the aluminosilicate glass or borosilicate glass described by the instant application. Therefore, this argument is not found to be persuasive.
Applicant further argues that one having ordinary skill in the art would also not be motivated to use an aluminosilicate or borosilicate material based on the teachings of Ehm, citing that the highest reflectivity is observed when the layer is a Si material. Thus, one having ordinary skill, in an effort to optimize or increase reflectivity would deduce that Si should be used, and not the silicate glass materials. However, the Examiner does not agree with this argument. Applicant cites Fig. 6A, 6B, and 8B-H of Ehm to show the materials examined by Ehm. None of these figures include an aluminosilicate or borosilicate material. It cannot be concluded based on the disclosure of Ehm that these materials have worse (or better) reflectance properties. Thus, one having ordinary skill in the art would not necessarily be dissuaded from trying to use such materials, as the results are not disclosed by the art to be better or worse. Per MPEP 2143 I. E., it would at the very least be an obvious variant to try based upon the disclosure of Ehm. Secondly, one having ordinary skill in the art does not necessarily require the highest reflectivity of the layer. An “optimal” reflectivity value does not need to be the highest reflectivity, and also depends on the exposure wavelength. Thus, one having ordinary skill would still be motivated to explore the aluminum silicate or boron silicate materials, per the suggestion of Ehm. Therefore, Applicant’s arguments are not found to be persuasive and the previous rejection is not withdrawn.
Applicant also argues that the combination of Ehm and Castanie, as applied to claims 7-8 and 18, is improper for three reasons. The first reason is that Ehm does not teach glassy materials, which is addressed above. The second reason is that Ehm does not teach or suggest cracks or defects in the optical element coatings. However, as noted in paragraph 4 of the office action filed 10 June 2025, the interpretation of claim 1 under the broadest reasonable interpretation of the claim does not require the presence of a crack or gap, and instead only requires that the intermediate be capable of forming reaction products that can seal a gap in the capping layer. Castanie is relied upon for the teachings of the introduction of a reactive material into the glass material, as well as the teaching of how to utilize said reactive material to form a reaction product. The third reason is that Castanie does not teach the application of the procedure to optical elements. However, Castanie is deemed to be analogous art because like Ehm, it pertains to producing protective layers. Thus, one having ordinary skill in the art would still be motivated to explore the teachings of Castanie in combination with Ehm, due to the similarities in functions of the two references. Thus, this argument is also not found to be persuasive.
Claim Interpretation
Instant claim 1 is directed to an optical element for reflecting extreme ultraviolet (EUV) radiation. Instant claim 1 recites that the optical element comprises “an intermediate layer arranged between the reflective coating and the capping layer, wherein the intermediate layer comprises at least one reactive material, which, together with an activating gas penetrating through a gap in the capping layer, forms at least one reaction product sealing the gap, and wherein the intermediate layer has at least one ply composed of a glass material.” The recitation “wherein the intermediate layer comprises at least one reactive material, which, together with an activating gas penetrating through a gap in the capping layer, forms at least on reaction product sealing the gap” is being interpreted by the Examiner as a preamble statement reciting purpose or intended use, per MPEP 2111.02 II. Under the broadest reasonable interpretation of claim 1, per MPEP 2111, the intermediate layer must comprise at least one reactive material that is capable of reacting with an activating gas, and must further comprise at least one ply composed of a gas material. However, the broadest reasonable interpretation of claim 1, as currently written, does not require a gap in the capping layer that is sealed with the reaction product formed by contacting the intermediate layer with an activating gas. In other words, claim 1 requires that the intermediate layer is capable of forming reaction products that can seal a gap in the capping layer, but does not require a capping layer having a gap that is sealed.
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.
Claim(s) 1-6 and 9-17 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2013/124224 A1 (hereby referred to as Ehm).
Regarding Claims 1-2 and 5-6, Ehm discloses an optical element and a method for optimizing a protective layer for an optical element. The optical element disclosed by Ehm comprises a multilayer system (51) applied to a substrate (52), wherein the multilayer comprises alternating layers of high refractive index (55) and low refractive index (54) materials, which forms a pair (53). See Fig. 2A and 2B of Ehm, as well as page 16 line 15 through page 17 line 5. The multilayer materials may include molybdenum (Mo) and silicon (Si), but alternative combinations may be utilized (Ehm, page 17 lines 7-17). As seen in Fig. 2B of Ehm, a protective layer system (59) is formed over the multilayer, wherein the protective layer system comprises two layers (57 and 58), though the protective layer system may comprise more than two layers (Ehm, page 17 line 28 through page 18 line 11). The upper layer (57) of the protective layer system is considered analogous to the capping layer of the instant application, and the lower layer (58) is considered analogous to the intermediate layer of the instant application. In embodiments in which more than two layers are used as the protective layer system, the upper layer is considered analogous to the capping layer, and the layers beneath the upper layer but above the reflective multilayer are considered analogous to the intermediate layer, wherein each layer constitutes a “ply” as recited by the instant application. The upper layer of the protective layer system is chemically stable and does not react with reactive hydrogen and offers a barrier effect for hydrogen ions, indicating the upper layer is a protecting layer (Ehm, page 18 line 26 through page 19 line 2). The lower layer(s) of the protective layer system includes reactive materials, and may be selected from the group comprising Y, Ce, Zr, Nb, Si, Ti, V, Mo, Mn, Al, W, Cr, La, Co, Ru, B, Hf, U, Be, and the oxides, carbides, nitrides, silicates, and borides thereof (Ehm, page 24 lines 19-25). Ehm does not explicitly disclose an embodiment wherein the lower layer (58) includes two layers, wherein one of the layers is a glass ply and the other layer is a reactive material. However, an intermediate layer comprising an aluminosilicate or borosilicate glass ply and a reactive material consisting of a boride, silicide, or carbide would be considered an obvious species derived from the genus disclosed by Ehm. Specifically, Ehm discloses a genus (a lower layer, which may comprise a plurality of lower layers, wherein the material of said layers is chosen from the group comprising Y, Ce, Zr, Nb, Si, Ti, V, Mo, Mn, Al, W, Cr, La, Co, Ru, B, Hf, U, Be, and the oxides, carbides, nitrides, silicates, and borides thereof), and provides specific examples of suitable compounds (such as B4C, Si-3N4, etc. (see Fig. 6A and 6B of Ehm)). Thus, whilst the specific combination of an aluminosilicate or borosilicate ply in combination with a boride, carbide, or silicide reactive material is not explicitly disclosed by Ehm, one having ordinary skill in the art would find this combination to be an obvious variant of the genus disclosed by Ehm. See MPEP 2144.08. One having ordinary skill in the art would be motivated to make this species selection to achieve a desired reflectivity of the protective layer system (i.e. the capping layer + intermediate layer) (Ehm, page 25 lines 11-26). This obvious variant suggested by Ehm yields an intermediate layer for an optical element wherein the intermediate layer comprises at least one reactive material selected from the group consisting essentially of borides, silicides, and carbides and a ply composed of an aluminosilicate glass or a borosilicate glass.
Regarding Claims 3-4, as noted above, independent claim 1, as currently written, does not require an activating gas present in the optical element. Rather, independent claim 1, as currently written, requires that the reactive material present in the intermediate layer be reacting with an activating gas. Ehm discloses that the reactive material of the intermediate layer includes borides, silicides, and/or carbides (Ehm, page 24 lines 19-25). Vanadium (V) is described as a suitable material, as is vanadium boride (VB) (Ehm, page 24 lines 19-25). Vanadium boride (VB) is described by the instant application’s specification (see paragraph 052 of the instant application’s specification) as a preferred reactive material, and it, by the applicant’s own admission (see paragraphs 016 046 of the instant application’s specification), can react with an activating gas such as O2 gas or water. Therefore, whilst not explicitly disclosed by Ehm, the reactive material of Ehm is capable of reacting with an activating gas.
Regarding Claims 9-10, Ehm discloses that the second layer (58) may include a plurality of “lower layers” (Ehm, page 17 line 28 through page 18 line 11). When the second layer comprises a plurality of lower layers, the reactive material can be present in more than one ply of the intermediate layer structure. Furthermore, Ehm discloses that the second layer (58) (which corresponds to the intermediate layer of the instant application) has a thickness of approximately 5 nm to up to 15 nm, which, in an embodiment wherein the second layer comprises more than one layer, can be divided among a plurality of the lower layers (58) (Ehm, page 24 lines 5-17). Per MPEP 2144.05 I., when the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.
Regarding Claim 11, Ehm discloses that the protective layer system, which includes both the capping layer and the intermediate layer, is applied to the reflective multilayer system with the aid of conventional coating methods, such as deposition from the gas phase, chemical vapor deposition (CVD), physical vapor deposition (PVD), sputtering, and the like (Ehm, page 5 lines 1-8).
Regarding Claims 12-13, Ehm discloses that the upper layer (57) of the protective layer system, which is analogous to the capping layer of the instant application, may be a material selected from the group of oxides, carbides, nitrides, silicates, and borides of the chemical elements Y, Ce, Zr, Nb, Si, Ti, V, Mo, Mn, Al, W, Cr, La, Co, Ru, B, Hf, U, and Be (Ehm, page 19 lines 4-16). In particular, Ehm prefers materials such as Y2O3, Ce2O3, ZrO2, CeO2, Nb2O2, and NbO as the upper layer (57) of the protective layer system (Ehm, page 21 lines 11-26, see also Fig. 3-4 of Ehm).
Regarding Claim 14, Ehm discloses that the upper layer (57) of the protective layer system, which is analogous to the capping layer of the instant application, should have a thickness of 5 nm or less, and preferably the thickness if between 1 nm and 2 nm (Ehm, page 24, lines 5-17). Per MPEP 2144.05 I., when the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.
Regarding Claims 15-16, Ehm discloses that the multilayer comprises alternating layers of high refractive index (55) and low refractive index (54) materials, which forms a pair (53). The alternating pairs may be formed of, for instance, Mo/Si, Mo/Be, Ru/Be, or La/B4C. The multilayer is described as reflecting EUV light (light having a wavelength of 13.5 nm) with substantially normal incidence. See Ehm, page 16 line 15 through page 17 line 17. Whilst Ehm is silent in regards to grazing incidence, the multilayer disclosed by Ehm should inherently be configured for grazing incidence. For example, paragraph 030 of the instant application’s specification states that “A reflective coating configured for grazing incidence typically has a reflectivity maximum at at least one angle of incidence that is greater than 60°. Such a reflective coating is typically formed from at least one material which has a low refractive index and low absorption for the EUV radiation incident with grazing incidence. In this case, the reflective coating can contain a metallic material or can be formed from a metallic material, for example composed of Mo, Ru or Nb.” As the reflective multilayer disclosed by Ehm may include alternating layers of Mo/Si, Mo/Be, or Ru/Be, it would thus be expected that the multilayer grating disclosed by Ehm inherently can be configured for grazing incidence, as the reflective multilayer comprises materials that, by the Applicant’s own admission, allow for the multilayer to be configured for grazing incidence.
Regarding Claim 17, Ehm discloses that the optical element is used in an EUV lithography system (Ehm, page 3 line 14-17). The EUV lithography apparatus comprises one or more of the optical elements (Ehm, page 15 line 16 through page 16 line 13, see also Fig. 1 of Ehm).
Claim(s) 7-8 and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2013/124224 A1 (hereby referred to as Ehm) as applied to claim 1 above, and further in view of 2D- and 3D Observation and Mechanism of Self-Healing in Glass–Boron Composites (hereby referred to as Castanie).
Regarding Claims 7-8, Ehm discloses an EUV optical element according to instant claim 1, as discussed above. Ehm renders obvious intermediate layer for an optical element wherein the intermediate layer comprises at least one reactive material selected from the group consisting essentially of borides, silicides, and carbides and a ply composed of an aluminosilicate glass or a borosilicate glass.
However, Ehm is silent in regards to the reactive material being introduced into the glass material. Castanie teaches glass-boron composites that undergo self-healing. The composites are obtained by mixing boron particles with glass powder and sintering the mixture at elevated temperatures (Castanie, Experimental Procedure). In this case, the boron particles are comparable to the reactive borides disclosed by Ehm, whilst the glass is comparable to the aluminosilicate or borosilicate glass disclosed by Ehm. The method of forming the glass composite taught by Castanie, when applied to the materials disclosed by Ehm, would yield an aluminosilicate or borosilicate glass doped with reactive boride particles.
Ehm and Castanie are analogous art because both references pertain to producing protective layers (see Ehm, page 3 lines 14-17; and Castanie, first paragraph of the “Introduction” section). It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to incorporate the reactive boride material of Ehm into the aluminosilicate or borosilicate glass layer in the form of nanoparticles, as taught by Castanie, because dispersing the reactive material into the glass allows for the reactive material, when exposed to an activating gas such as oxygen, to more efficiently fix cracks or other defects in the glass. See Castanie, last paragraph in the first column of page 851.
Regarding Claims 18-20, Ehm discloses an EUV optical element according to instant claim 1, as discussed above. Ehm renders obvious intermediate layer for an optical element wherein the intermediate layer comprises at least one reactive material selected from the group consisting essentially of borides, silicides, and carbides and a ply composed of an aluminosilicate glass or a borosilicate glass.
However, Ehm is silent in regards to sealing a gap in a capping layer of the optical element. Castanie teaches glass-boron composites that undergo self-healing. The composites are obtained by mixing boron particles with glass powder and sintering the mixture at elevated temperatures (Castanie, Experimental Procedure). In this case, the boron particles are comparable to the reactive borides disclosed by Ehm, whilst the glass is comparable to the aluminosilicate or borosilicate glass disclosed by Ehm. The method of forming the glass composite taught by Castanie, when applied to the materials disclosed by Ehm, would yield an aluminosilicate or borosilicate glass doped with reactive boride particles. Castanie further teaches that the glass possesses cracks (analogous to the gap recited by instant claim 18) and the cracks are exposed to an activating gas (O2 in oxidizing conditions) (Castanie, second paragraph in the first column of page 850). As shown by Fig. 3 of Castanie (see page 851 of Castanie), the crack is increasingly “healed” over time during the activating gas exposure. The healing of the crack is considered analogous to the “sealing the gap with the formed reaction product” step recited by instant claim 18, as Castanie teaches that the boron particles are oxidized by the O2 to form boron oxide (which is a reaction product), and the boron oxide is what “heals” the crack. See Castanie, last paragraph in the second column of page 850 through the first column of page 851. The Examiner notes that when this process is performed, a crack (analogous to the gap recited by instant claim 1) is sealed by the reaction product, thereby yielding the optical element according to instant claims 19 and 20.
Ehm and Castanie are analogous art because both references pertain to producing protective layers (see Ehm, page 3 lines 14-17; and Castanie, first paragraph of the “Introduction” section). It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to repair a gap in the capping layer of the optical element disclosed by Ehm by producing a reaction product formed by reacting an activating gas with the reactive material, as taught by Castanie, because producing an activating gas in the presence of the reactive material produces a reaction product that more efficiently fixes cracks or other defects in the glassy material. See Castanie, last paragraph in the first column of page 851. Furthermore, repairing a gap in the capping layer in such a way is repeatable (Castanie, Introduction) and allows for the extension of the usage life of the optical element.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/JAYSON D COSGROVE/Examiner, Art Unit 1737
/JONATHAN JOHNSON/Supervisory Patent Examiner, Art Unit 1734