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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 June 5, 2026, has been entered.
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 1-10 and 21-25 are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki ’409 (US 2025/0154409 A1) in view of Yokohama et al (US 2022/0157610 A1) and Xu et al (US 2020/0058585 A1).
Suzuki ’409 discloses an etching gas comprising:
a halogen gas (chlorine gas [0044], bromine or iodine as impurities [0061], [0071]-[0072]);
a first gas that includes a phosphorus atom (phosphorus trifluoride [0036]);
a second gas that includes a carbon atom and two or more halogen atoms that are different from each other (e.g., chlorinated hydrocarbons that include chlorine and fluorine [0045], [0046]; or bromine and fluorine [0048] [0049]; or iodine and fluorine [0050]).
Suzuki ’409 discloses that the etching compounds may be used alone or in combination of two or more types thereof. [0051]. Thus, a combination of the halogen gas, first gas and second gas may be used. More specifically, a fluorine-containing gas may be combined with a gas that includes chlorine, bromine, or iodine, including those that include chlorine and fluorine [0045], [0046]; or bromine and fluorine [0048] [0049]; or iodine and fluorine [0050].
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include a second gas as cited in the composition of Suzuki ’409 because Suzuki ’409 teaches that the etching compounds may be used alone or in combination of two or more types thereof including those that contain chlorine, chlorine and fluorine, bromine and fluorine, or iodine and fluorine.
Yokohama teaches the obviousness of choosing a phosphorus-containing gas as the fluorine gas, in combination with other halogens (e.g., chlorine as in claim 1, or HBr as in claims 10, 23) or hydrofluorocarbon gases (e.g., as in claims 9 and 22).
Both Yokohama (etching silicon-containing films, abstract, [0056]) and Suzuki ’409 (etching silicon-containing films [0028], [0083]) teach an etching composition for etching silicon-containing films. Yokohama teaches that the etching composition may comprise
a phosphorus gas component,
a fluorine gas component,
a hydrogen gas component,
a hydrofluorocarbon gas component, and
a halogen component other than the fluorine component [0093].
Yokohama teaches that the phosphorous component may include PF3, as in Suzuki ’409, but also other phosphorus- and fluorine-containing compounds [0090].
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to pick a phosphorus-containing compound as the fluorine-containing compound to combine with halogen compounds in the composition of Suzuki ’409 because Yokohama teaches that to do so is known and useful for etching silicon-containing films.
Suzuki ’409 fails to disclose to include hydrogen gas. Suzuki ’409 discloses that the composition includes a dilution gas [0057]. Suzuki ’409 discloses that the type of dilution gas is not limited, but includes argon or nitrogen gas [0057]. Xu et al (US 2020/0058585 A1) teaches that a dilution gas may comprise argon, nitrogen or hydrogen [0053].
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include hydrogen gas in the etching gas of Suzuki ’409 because Xu teaches that it is a functionally equivalent dilution gas to include in the composition for argon and nitrogen.
As to amended claim 1, it is agreed with applicant’s arguments (see first paragraph of page 3 of arguments filed June 5, 2026) that the cited flow rates is equivalent to citing a concentration of the gases in the composition. 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 flow rates in the modified composition of Suzuki ’409 because the concentration can be optimized for best results. MPEP 2144.05, II. A.
As to claim 2, Suzuki ’409 discloses to include a halogen atom, see the rejection of claim 1.
As to claim 3, Yokohama teaches that phosphorus pentafluoride is a useful alternative for phosphorus trifluoride in the etching composition. [0090]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include phosphorus pentafluoride in the composition of Suzuki ’409 because Yokohama teaches that it is a useful alternative for phosphorus trifluoride and such is expected to give the predictable result of a useful etching composition.
As to claims 4-6, see the rejection of claim 1.
As to claims 7 and 25, Suzuki ’409 discloses that the chlorine-containing gas may comprise chlorotrifluoroethylene C2ClF3 [0046]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include chlorotrifluoroethylene as the chlorine-type gas in the composition of Suzuki ’409 because Suzuki ’409 teaches that the gases may be used in combination and specifically lists chlorotrifluoroethylene as a useful example of a chlorine-type gas to include, and the combination is expected to give the predictable result of an etching composition for etching silicon-containing films.
As to claim 8, Yokohama teaches that phosphorus oxychloride is a useful alternative for phosphorus trifluoride in the etching composition. [0090]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include phosphorus oxychloride in the composition of Suzuki ’409 because Yokohama teaches that it is a useful alternative for phosphorus trifluoride and such is expected to give the predictable result of a useful etching composition.
As to claims 9-10, Suzuki ’409 discloses to include an etching gas with carbon and one type of halogen atom (chain saturated perfluorocarbon, [0037], cyclic perfluorocarbon [0041], chain saturated brominated hydrocarbons [0048], trifluoroiodomethane [0050]) or a halogenated hydrogen gas (e.g. HCl, [0044], HBr [0047], HI [0050]). Suzuki ‘409 teaches two or more types of compounds may be combined [0055]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include an etching gas with carbon and one type of halogen atom or a halogenated hydrogen gas as cited in the composition of Suzuki ’409 because Suzuki ’409 teaches that the etching compounds may be used alone or in combination of two or more types thereof, including those that contain carbon and one type of halogen or hydrogen, as cited.
As to claim 21, see the rejection of claim 1.
As to claims 22-23, Suzuki ’409 discloses the species cited, CH2F2 [0038] and HBr [0047]. It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to include CH2F2 or HBr in the composition of Suzuki ’409 because Suzuki ’409 teaches that they are useful species to include in the composition and such are expected to give the predictable result of an etching solution.
As to claim 24, Yokohama teaches that the phosphorous component may include PF3, as in Suzuki ’409, but also teaches that other phosphorus- and fluorine-containing compounds are useful to include [0090]. Examples include phosphorus halides such as phosphorus pentafluoride PCl5, phosphorus pentachloride PCl5, phosphorus pentabromide PBr5, and phosphoryl halides, such as phosphoryl fluoride POF3, phosphorus oxychloride POCl3 and phosphoryl bromide POBr3 [0090]. Yokohama thus teaches the cited PX5 or P(=O)X3. 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 PX5 or P(=O)X3 in the composition of Suzuki ’409 because Yokohama teaches that they are useful phosphorus containing gases to include and functionally equivalent to the PF3 of Suzuki ’409, and such is expected to give the predictable result of an etching composition.
Response to Amendment
Claims 1-10 and 21-25 remain rejected under 35 U.S.C. 103 as being unpatentable over Suzuki ’409 (US 2025/0154409 A1) in view of Yokohama et al (US 2022/0157610 A1) and Xu et al (US 2020/0058585 A1).
The amendment to claim 25 is sufficient to overcome any possible objection due to duplicate claims.
Response to Arguments
Applicant's arguments filed June 6, 2026, have been fully considered but they are not persuasive, to the extent they still apply.
Applicant argues that there are superior results with the newly cited flow rates. More specifically, applicant argues that Figures 3 and 4 of the instant specification demonstrate that polysilicon selectivity is maximized when the amount of the first gas is 5 times or less than that of the second gas. This argument is not persuasive. As an initial matter, “5 times or less” is a relative term. In Figure 3, the flow rate of PF5 is 100 sccm, and the flow rate of chlorotrifluoroethylene varied from 0 to 100 sccm. Thus at one point, the flow rates are equal (100 sccm), and at other data points with the large selectivity, the flow rate is 20, 40, 60, or 80 sccm. But claim 1 does not describe a flow rate of 20-100 sccm. Claim 1 is open to a flow rate of 0-20 sccm, so long as the ratio is 5 or less. Such a flow rate may or may not produce the alleged superior results. There is insufficient data to know.
Figures 3 and 4 present data points at zero through 100 sccm. There is insufficient data points outside of this depicted range, greater than 100 sccm, to show that the results in the depicted range are unexpected.
Relying on flow rate is problematic too because chambers have different sizes so that the flow rate significance is difficult to appreciate.
Moreover, the claim recites the composition at a high level of generality, while the results relied upon are for specific gases. A claim has not been presented that is directed to the particular gases and flow rates relied upon for the alleged superior results. Accordingly, the claims are not commensurate in scope with the alleged superior results.
Conclusion
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/ANITA K ALANKO/ Primary Examiner, Art Unit 1713
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