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 .
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.
Claims 1, 2, 4, 5, 11-13, 15 and 17-19 are rejected under 35 U.S.C. 102(a)(1) as being anticipated US Publication 2022/0157614 to Oomori et al.
Regarding Claims 1, 12 and 17, Oomori et al. teaches an etching method for forming an structure by selectively etching one or more dielectric films (Paragraph 27) in a substrate using a patterned mask layer (photoresist) deposited on top of the one or more dielectric films, the method comprising: mounting the substrate (18) in a reaction chamber (11); introducing an etching gas containing C₂H₂F₂ into the reaction chamber (Paragraph 26); converting the etching gas to a plasma; and allowing an etching reaction to proceed between the plasma and the one or more dielectric films so that the one or more dielectric films are selectively etched versus the patterned mask layer (photoresist) to form the aperture.
Regarding Claims 2 and 13, Oomori et al. teaches (Paragraph 25) adding one or more hydrofluorocarbon or fluorocarbon etching gases to the etching gas C₂H₂F₂, wherein the one or more hydrofluorocarbon or fluorocarbon etching gases are selected from CF₄, C4F6, C4F8, C4H₂F₆, CHF₃, CH₂F₂, CH₃F, C₂F₆, C3F8, SF₆, NF₃, C₂F₄, C3F₆, C4F₁₀, C₅F₈, C₆F₆, C₁-C₆ CxFyH₂ molecule (x, y, and Z are integers), C₂H₅F, C₃H₇F, C₃H₂F₆, C₂HF₅, C₃H₂F₄, or combination thereof.
Regarding Claims 4, 5, 15 and 17-19, Oomori et al. teaches (Paragraph 42) adding an inert gas to the etching gas C₂H₂F₂, wherein the inert gas is selected from Ar, Kr, Xe, Ne, N₂, He or combination thereof.
Regarding Claims 11 and 12, Oomori et al. teaches the method of the invention substantially as claimed but does not expressly teach CO2 emissions are 10% lower than using CF4 as an etching gas. However, the same emissions are a result of the etching gas and process conditions and would reasonably be expected to be the same or else are the result of essential limitations which have not been claimed.
Regarding Claim 17, as applied above, Oomori et al. teaches the method of the invention substantially as claimed including (Paragraph 46) a substrate temperature ranges from -20 to 300°C
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 3 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2022/0157614 to Oomori et al. in view of US Publication 2023/0215700 to Kumagai et al.
Regarding Claims 3 and 14, as applied above, Oomori et al. teaches the method of the invention substantially as claimed, but does not expressly teach adding an additive to the etching gas C₂H₂F₂, wherein the additive is selected from H₂, SF₆, NF₃, NH₃, Cl₂, BCl₃, BF₃, Br₂, F2, FNO, FNO3, HBr, HCI, HI, IF5, IF₇ or HF. However, Kumagai et al. teaches (Paragraphs 102, 109, 113) additives for CxHyFx dielectric stack etching include the additive is selected from H₂, SF₆, NF₃, NH₃, Cl₂, BCl₃, BF₃, Br₂, F2, FNO, FNO3, HBr, HCI, HI, IF5, IF₇ or HF. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the additive gasses to etch a dielectric stack with predictable results.
Claims 6-9, 16 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2022/0157614 to Oomori et al. in view of US Publication 2020/00234962 to Kato et al.
Regarding Claims 6-9, 16 and 20, as applied above, Oomori et al. teaches the method of the invention substantially as claimed including C₂H₂F₂ etch gas, but does not expressly teach isomers. However, isomer alternatives are well known for etching gas processing. For example, Kato et al. teaches (Paragraphs 137-141) isomers as alternatives for C₂H₂F₂. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the 4 isomers of C₂H₂F₂ as an etch gas with predictable results.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2022/0157614 to Oomori et al. in view of US Publication 2005/0266691 to Gu et al.
Regarding Claims 10, as applied above, Oomori et al. teaches the method of the invention substantially as claimed including C₂H₂F₂ etch gas for silicon compound films such as silicon oxide and nitride (Paragraphs 3-4), but does not expressly teach SiCOH films. However, Gu et al. teaches etching a recess in silicon containing films such as silicon oxide and SiCOH (See at least Abstract and Paragraphs 82 and 189) using CxHyFx etch gas mixtures. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the silicon containing films such as silicon oxide and SiCOH in the method of Oomori et al. in order to form a recess with predictable results.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US Publication 2015/0097276 to Kim et al. teaches etching alternating oxide and nitride layers with gas containing C₂H₂F₂.
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/ROBERTS P CULBERT/Primary Examiner, Art Unit 1716