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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on March 27, 2026, has been entered.
Election/Restrictions
Claims 14-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on July 18, 2025.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-7 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (US 12,154,790 B2) in view of Shen et al (US 11,075,084 B2).
Watanabe discloses an etching gas composition (abstract) comprising:
at least two C3 or C4 organic fluorine compounds (“fluorocarbon gas may include one or more of C4F6, C4F8, C3F8, and CF4” col.4, lines 11-17, 30-32); and
molybdenum fluoride (col.4, lines 11-20); and
a reactive gas, wherein the reactive gas is oxygen gas (O2) (col.4, lines 32-34).
Watanabe fails to disclose to include that the carbon fluorine compounds that are isomers of each other. Watanabe discloses to etch silicon oxide (col.4, lines 35-36).
Shen teaches an etching gas composition with organic fluorine compounds. More specifically, Shen teaches to etch silicon oxide (col.10, line 41) with a hydrofluorocarbon etching gas including 1,1,1,3,3,3-hexafluoropropane and 1,1,2,2,3,3- hexafluoropropane (col.10, lines 58-59). The advantage of these compounds is that they provide high to infinite selectivity to photoresist layers, mask layers, etch stop layers and device channel materials (col.13, lines 23-25).
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include the isomers of 1,1,1,3,3,3-hexafluoropropane and 1,1,2,2,3,3- hexafluoropropane in the composition of Watanabe because Shen teaches that they provide high to infinite selectivity to photoresist layers, mask layers, etch stop layers and device channel materials, and such are expected to give the predictable result of an etched layer.
Further as to amended claim 1 as it relates to the mixing ratio, Shen teaches that the at least two C3 compounds comprises a first organic compound 1,1,1,3,3,3-hexafluoropropane (col.14, line 55) and a second organic compound 1,1,2,2,3,3- hexafluoropropane (col.14, lines 56-57),
wherein a volumetric mixing ratio x:y of the first organic compound to the second organic compound ranges from x=50-75 vol% and y=25-50 vol% (col.14, lines 53-57), which for an ideal gas, is expected to be about 50-75 mol% first organic compound and 25-50 mol% second organic compound, which are ranges that overlap with the cited ranges. The gases are treated as ideal gases for the purposes of defining the composition. Shen also teaches that mixtures of isomers provides improved process parameters or can save money (col.14, lines 48-52).
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 ranges of molar ratios in the composition of Watanabe because Shen teaches that such ranges are useful and are expected to give the predictable result of a composition useful for etching. It would have also been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to vary the mixing ratio to that cited because Shen teaches that to do so provides improved process parameters or can save money, and to optimize the concentration for best results. MPEP 2144.05, II. A.
Further as to amended claim 1, the limitations that the mixing ratio is “selected such that an aspect ratio of a pattern formed using the etching gas composition varies depending on the mixing ratio without increasing the amount of oxygen gas in the etching gas composition” is a method limitation that is given little patentable weight in a composition claim. The mixing ratios of Watanabe as modified by Shen teach ratios within the cited range. Watanabe and Shen may adjust the mixing ratios for different reasons than applicant does, and still read on the claimed invention. Here, Shen teaches that mixtures of isomers provides improved process parameters or can save money (col.14, lines 48-52). This is sufficient motivation to choose mixing ratios that overlap with the cited range, as explained more fully above.
Moreover, the limitation of aspect ratio dependence is treated as a limitation of intended use of the composition and is given little patentable weight. The composition is expected to have the same properties of aspect ratio because if the composition is physically the same, it must have the same properties. MPEP 2112.01 II.
As to claims 2-4, see the rejection of claim 1.
As to claim 5, Shen teaches that the isomer of 1,1,1,2,3,3-hexafluoropropane is a known isomer to include in etching compositions (col.2, lines 25-32). It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include 1,1,1,2,3,3-hexafluoropropane as the first organic fluorine compound in the modified composition of Watanabe because Shen also teaches that 1,1,2,3,3-hexafluoropropane is a known isomer to include in etching compositions, and such is expected to give the predictable result of an etching composition.
It would have been further obvious to include 1,1,1,2,3,3-hexafluoropropane and the second organic fluorine compound of 1,1,1,3,3,3-hexafluoropropane or 1,1,2,2,3,3- hexafluoropropane at the molar ratio/mixing ratio in the modified composition of Watanabe because Shen teaches they are all known and useful isomers to include in etching compositions, and they are all expected to have the same function and work in the same way in the final composition.
It would have been further obvious to include the first and second organic fluorine compound at the molar ratio/mixing ratio in the modified composition of Watanabe in order to optimize the composition for best results because Shen already teaches to vary the amounts of isomers with respect to one another is useful, and varying them to optimize the composition is within the scope of one skilled in the art. It would have also been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to vary the mixing ratio to that cited because Shen teaches that to do so provides improved process parameters or can save money.
As to claim 6, see the rejection of claim 1.
As to claim 7, Watanabe discloses that the molybdenum hexafluoride gas may be included in an amount of 0.5 through 5 parts by volume based on 100 parts by volume of the etching gas composition (col.4, lines 27-29), which encompasses the cited range.
As to claim 12, Watanabe discloses to include an inert gas of a noble gas (col.4, lines 16-17). The cited gases are noble gases and would be immediately envisaged as a noble gas for inclusion in the composition of Watanabe.
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (US 12,154,790 B2) in view of Suzuki et al (US 2023/0386850 A1) and Shen et al (US 11,075,084 B2).
As to claims 8-9, Watanabe discloses an etching gas composition (abstract) comprising:
at least two C3 or C4 organic fluorine compounds (“fluorocarbon gas may include one or more of C4F6, C4F8, C3F8, and CF4” col.4, lines 11-17, 30-32); and
molybdenum fluoride (col.4, lines 11-20).
Watanabe fails to disclose to include that the organic fluorine compounds are C4H2F6 compounds that are isomers of each other. Watanabe discloses to etch silicon oxide (col.1, lines 42-47; col.4, lines 35-39).
Suzuki teaches that etching compositions for surfaces such as silicon oxide [0077]-[0078] may include C4 organic fluorine compounds [0037] including C4HxFy, x is 1-7, y is 1-7, x+y is 8 [0038]. Suzuki teaches that the type of fluorobutene is not limited [0038]. Suzuki teaches that the organic fluorine compounds include 1,1,1,4,4,4,-hexafluoro-2-butene (CF3-CH=CH-CF3)[0040], [0043]; 1,1,2,3,4,4-hexafluoro-2-butene [0040]; or 2,3,3,4,4,4-hexafluoro-1-butene [0043]. Further, Suzuki teaches that cis and trans isomers may be used. [0041].
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include the cited 2,3,3,4,4,4- and 1,1,2,3,4,4-hexafluoro-2-butene as the organic fluorine compound in the composition of Watanabe because Suzuki teaches that they are useful organic fluorine compounds to including in etching compositions, and such is expected to give the predictable result of an etchant.
The discussion of Shen from above is repeated here. Shen teaches that in etching gas compositions, that mixtures of isomers improve process parameters or save money (col.14, lines 48-52). For example, Shen teaches that the molar ratio/mixing ratio can be about 50-75 mol% first organic compound and 25-50 mol% second organic compound, which are ranges which overlap with the cited ranges. 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 molar ratio/mixing ratio of isomers in the modified composition of Watanabe because Shen teaches that to do can improve process parameters or save money. It is also obvious to optimize the concentration to the cited molar ratio/mixing ratio because the composition can be optimized for best results. MPEP 2144.05, II. A.
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (US 12,154,790 B2) in view of Suzuki et al (US 2023/0386850 A1) and Shen et al (US 11,075,084 B2), as applied to claim 9, and further in view of Kim et al (US 2022/0310407 A1).
As to claim 10, Watanabe fails to disclose to include that the cited hexafluoro-2-butene and 1,1,2,2,3,4-hexafluorocclobutane. Kim teaches to include organic fluorine compounds in etchant solutions. More specifically Kim teaches to include (2Z)-1,1,1,4,4,4,-hexafluoro-2-butene (CF3-CH=CH-CF3)and (3R,4S)-1,1,2,2,3,4-hexafluorocyclobutane (claim 8), as cited. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include the third and fourth organic fluorine compounds as cited in the modified composition of Watanabe because Kim teaches that they are useful organic fluorine compounds for compositions, and such are expected to provide the predictable result of an etchant composition.
As to claim 11, Suzuki teaches that hexafluoroisobutene is known and useful to include to improve etch selectivity [0003]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include the cited compounds as taught by Suzuki and Kim in the composition of Watanabe because they are expected to give the predictable result of a useful etchant and improve selectivity.
Response to Amendment
Applicant’s arguments, see page 6, filed March 27, 2026, with respect to the 35 USC 112 rejection has been fully considered and are persuasive.
Claims 1-7 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (US 12,154,790 B2) in view of Shen et al (US 11,075,084 B2).
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (US 12,154,790 B2) in view of Suzuki et al (US 2023/0386850 A1) and Shen et al (US 11,075,084 B2).
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Watanabe et al (US 12,154,790 B2) in view of Suzuki et al (US 2023/0386850 A1) and Shen et al (US 11,075,084 B2), as applied to claim 9, and further in view of Kim et al (US 2022/0310407 A1).
Response to Arguments
Applicant's arguments filed March 27, 2026, have been fully considered but they are not persuasive, to the extent they still apply.
Applicant argues that Shen discloses that oxygen flow rate is used as a parameter which affects etching characteristics such as etch rate and etch selectivity. In response, if this is true, which is not admitted, this is beside the point and not persuasive. The claims at issue are composition claims. The prior art can teach the cited mixing ratios for different reasons than applicant, and still read on the invention because a composition is defined by what it is, rather than by how it is used. Shen teaches mixing ratios that overlap with the cited ranges for reasons of economy or to improve process parameters (col.14, lines 50-52, 57-59). Accordingly, the claims are obvious over the combined teachings of Watanabe and Shen.
Shen also need not recognize the significance of aspect ratio because 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. MPEP 2112, I. Here, the claiming of aspect ratio and oxygen dependence does not make the claims patentable because Watanabe as modified by Shen teaches the cited mixing ratios.
The new limitation about aspect ratio may be persuasive in a method claim, but the method claims have been withdrawn from consideration.
Conclusion
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/ANITA K ALANKO/Primary Examiner, Art Unit 1713
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