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 1-5 and 12-20, in the reply filed on 12/09/2025 is acknowledged.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-5, 12-17, and 19 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tomura et al. (US-20230268191-A1).
Regarding Claim 1, Tomura teaches a method (Paragraph [0002] etching method taught) comprising:
providing a wafer, wherein the wafer comprises an oxide containing material layer (Paragraph [0026] substrate is provided that includes a silicon-containing film. Paragraph [0036] silicon-containing film can include silicon oxide film);
forming a mask comprising at least a pattern on a surface of the wafer, wherein the mask comprises an at least partially metallic material (Paragraph [0044] a mask is formed and can comprise tungsten, which is a metal. Paragraph [0045] Figure 2 the mask comprises a pattern on the surface of the wafer); and
selectively etching the mask and the wafer under the mask by using an etchant gas (Paragraphs [0083-0084] the mask (element MK) and film (element SF) are etched by a process gas), wherein the etchant gas is selected from a group consisting of CF4, CHF3, and NF3 (Paragraphs [0078-0080] the process gas may include NF3, CF4, or CHF3).
Regarding Claim 2, Tomura teaches wherein the oxide containing material layer comprises an oxide layer on a nitride layer (Paragraph [0043] the silicon-containing film can include a stack of alternating silicon oxide and silicon nitride films).
Regarding Claim 3, Tomura teaches wherein the oxide containing material layer comprises a stack of alternate oxide and nitride layers on top of each other (Paragraph [0043] the silicon-containing film can include a stack of alternating silicon oxide and silicon nitride films).
Regarding Claim 4, Tomura teaches wherein the at least partially metallic material comprises a tungsten containing material (Paragraph [0044] the mask may contain tungsten silicide).
Regarding Claim 5, Tomura teaches wherein the tungsten containing material comprises tungsten silicide (WSiX) (Paragraph [0044] the mask may contain tungsten silicide).
Regarding Claim 12, Tomura teaches a method (Paragraph [0002] etching method taught) comprising:
forming a mask comprising at least a pattern on a wafer, wherein the mask comprises an at least partially metallic material (Paragraph [0044] a mask is formed and can comprise tungsten, which is a metal. Paragraph [0045] Figure 2 the mask comprises a pattern on the surface of the wafer); and
selectively etching the mask and the wafer under the mask by using an etchant gas (Paragraphs [0083-0084] the mask (element MK) and film (element SF) are etched by a process gas), wherein the etchant gas is selected from a group consisting of CF4, CHF3, and NF3 (Paragraphs [0078-0080] the process gas may include NF3, CF4, or CHF3).
Regarding Claim 13, Tomura teaches wherein the wafer comprises an oxide containing material layer (Paragraph [0043] the silicon-containing film can include a stack of alternating silicon oxide and silicon nitride films).
Regarding Claim 14, Tomura teaches wherein the oxide containing material layer comprises an oxide layer on a top of a nitride layer (Paragraph [0043] the silicon-containing film can include a stack of alternating silicon oxide and silicon nitride films).
Regarding Claim 15, Tomura teaches wherein the oxide containing material layer comprises a stack of alternate oxide and nitride layers on top of each other (Paragraph [0043] the silicon-containing film can include a stack of alternating silicon oxide and silicon nitride films).
Regarding Claim 16, Tomura teaches wherein the at least partially metallic material comprises a tungsten containing material (Paragraph [0044] the mask may contain tungsten silicide).
Regarding Claim 17, Tomura teaches wherein the tungsten containing material comprises tungsten silicide (WSiX) (Paragraph [0044] the mask may contain tungsten silicide).
Regarding Claim 19, Tomura teaches wherein the etchant gas consists of CHF3 (Paragraph [0078] all of the HF gas may be a gas for generating an HF species. Paragraph [0079] the gas for generating a HF species may be a hydrofluorocarbon gas. Paragraph [0080] CHF3 is a hydrofluorocarbon gas).
Claim Rejections - 35 USC § 103
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Tomura in view of Cai et al. (US20150287648-A1).
Regarding Claim 18, Tomura teaches all the limitations of claim 12 as outlined above. Tomura teaches that the film to be etched can be a silicon-containing film, such as polycrystalline silicon (Paragraph [0043]).
Tomura fails to teach that the etchant gas consists of CF4.
Cai teaches methods related to forming semiconductor devices (Paragraph [0002]). Cai teaches an etching method that utilizes a pattern in a mask layer to etch a cavity into an underlying layer that can be silicon or other (Paragraph [0044] mask layer (element 108) has openings that expose substrate layer (element 106) and cavities are etching into the substrate layer by the second etching process. Paragraph [0036] the bulk substrate layer (element 106) can be silicon). The etching of the silicon layer can be conducted with a process gas that consists of CF4 (Paragraph [0044] the second etching process consists of CF4).
It would have been obvious to one of ordinary skill in the art to have modified the method of Tomura by utilizing an etching gas that consists of CF4 as taught by Cai.
It would be obvious to one of ordinary skill in the art to substitute the etching gas taught by Tomura with an etching gas consisting of CF4 as taught by Cai since CF4 is an etching gas suitable for etching silicon and the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See MPEP 2144.07. Additionally, this modification could be considered the simple substitution of one etching gas for another. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See MPEP §2143(B).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Tomura in view of Thedjoisworo et al. (US20150287648-A1).
Regarding Claim 20, Tomura teaches all the limitations of claim 12 as outlined above. Tomura teaches that the film to be etched can be a silicon-containing film, such as silicon oxide (Paragraph [0043]).
Tomura fails to teach that the etchant gas consists of CF4.
Thedjoisworo teaches methods that include etching silicon oxide and silicon layers (Paragraph [0002]). Teaches that the etching process can include the use of an etchant gas that consists of NF3, where a plasma is used to cause etching (Paragraph [0073]). Thedjoisworo teaches that the use of NF3 as the etching gas for a plasma etching can result in a high etch rate and avoid attacking of sidewalls (Paragraph [0073]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Tomura by utilizing an etching gas that consists of NF3 as taught by Thedjoisworo.
One of ordinary skill in the art would have been motivated to make this modification because Thedjoisworo teaches that the use of NF3 as the etching gas can result in a high etch rate and avoid attacking sidewalls during the etch (Paragraph [0073]). Additionally, it would be obvious to one of ordinary skill in the art to substitute the etching gas taught by Tomura with an etching gas consisting of NFs as taught by Thedjoisworo since NF3 is an etching gas suitable for etching silicon oxide and the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See MPEP 2144.07.
Conclusion
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/A.K.L./Examiner, Art Unit 1713 /DUY VU N DEO/Primary Examiner, Art Unit 1713