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 .
Status of the Claims
This is a final office action in response to the applicant’s arguments and remarks filed on 08/21/2026. Claims 1-18 and 20 are pending in the current office action. Claims 1, 12, and 15 have been amended by the applicant. Claims 6-11 remain withdrawn.
Status of the Rejection
All 35 U.S.C. § 112(b) rejections from the previous office action are withdrawn in view of the Applicant’s amendment.
The rejection of claim 19 is obviated by the Applicant’s cancellation.
Some of the 35 U.S.C. § 102 and 103 rejections from the previous office action are substantially maintained and modified only in response to the amendments to the claims.
Some 35 U.S.C. § 102 and 103 rejections from the previous office action are withdrawn in view of the Applicant’s amendment.
New grounds of rejection under 35 U.S.C. § 103 are necessitated by the amendments.
Claim Rejections - 35 USC § 102
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 1-5, 12-17 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 and NF3 (Paragraphs [0078-0080] the process gas may include NF3 or CF4. Note: Examiner takes the position that this meets the instant limitations. The method taught by Tomura would require additional gases to be included with NF3 or CF4, but the inclusion of additional gases to be supplied alongside, or as part of, the claimed “etchant gas” is not excluded in the instant claim. Examiner notes that this interpretation is implied by the presented claims where claims 18 and 20 further limit the limitation “wherein the etchant gas is selected from a group consisting of CF4 and NF3” of claim 12, by reciting “wherein the etchant gas consists of” NF3 or CF4).
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 and NF3 (Paragraphs [0078-0080] the process gas may include NF3 or CF4. Note: Examiner takes the position that this meets the instant limitations. The method taught by Tomura would require additional gases to be included with NF3 or CF4, but the inclusion of additional gases to be supplied alongside, or as part of, the claimed “etchant gas” is not excluded in the instant claim. Examiner notes that this interpretation is implied by the presented claims where claims 18 and 20 further limit the instant limitation “wherein the etchant gas is selected from a group consisting of CF4 and NF3”, by reciting “wherein the etchant gas consists of” NF3 or CF4).
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).
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 1-3, 12-15, 18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Togo et al. (US-20230389317-A1) in view of Lin (US-20230360925-A1).
Regarding Claim 1, Togo teaches a method (Paragraph [0004] a method is taught) comprising:
providing a wafer, wherein the wafer comprises an oxide containing material layer (Paragraphs [0145-0146] Figure 9 a substrate is provided that includes an alternating stack (elements 232 and 242) of layers that can be silicon oxide and silicon nitride);
forming a mask comprising at least a pattern on a surface of the wafer (Paragraph [0145] an etch mask is formed on the substrate and patterned. Paragraph [0187] the etch mask can be a hard mask material that is an insulating, semiconductor, or conductive material); and
selectively etching the wafer under the mask by using an etchant gas, wherein the etchant gas is selected from a group consisting of CF4 and NF3 (Paragraphs [0145-0146] openings are formed by an etching process that selectively etches to make the openings, and the etching process uses CF4 or NF3).
Togo fails to teach wherein the mask comprises an at least partially metallic material. Togo fails to explicitly teach that the mask is etched during the etching process.
Lin teaches methods related to etching features (Paragraph [0001]). Lin teaches the use of metal silicides as hard mask layers within a hard mask structure (Paragraph [0012] metal silicides can be used within a hard mask). Lin teaches that silicon containing layers within a hard mask structure can be etched during an etching process, acting as sacrificial layers that can result in improved feature profiles (Paragraph [0013]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Togo by selecting as a material for the hard mask a metal silicide as taught by Lin and causing the mask layer to be etched during the etching process.
One of ordinary skill in the art would have been motivated to make this selection because the use of a silicon-containing material, such as those taught by Lin, in the hard mask could have allowed for the mask layer to be etched during the etching process as a sacrificial material which would have allowed for improved feature profiles (Lin Paragraph [0013]). Additionally, it would be obvious to one of ordinary skill in the art to select as the hard mask material in the method of Togo a metal silicide as taught by Lin since metal silicides are known as hard mask materials 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.
Regarding Claim 2, Togo teaches wherein the oxide containing material layer comprises an oxide layer on a nitride layer (Paragraphs [0145-0146] Figure 9 a substrate is provided that includes an alternating stack (elements 232 and 242) of layers that can be silicon oxide and silicon nitride).
Regarding Claim 3, Togo teaches wherein the oxide containing material layer comprises a stack of alternate oxide and nitride layers on top of each other (Paragraphs [0145-0146] Figure 9 a substrate is provided that includes an alternating stack (elements 232 and 242) of layers that can be silicon oxide and silicon nitride).
Regarding Claim 12, Togo teaches a method (Paragraph [0004] a method is taught) comprising:
Forming a mask comprising at least a pattern on a wafer (Paragraph [0145] an etch mask is formed on the substrate and patterned. Paragraph [0187] the etch mask can be a hard mask material that is an insulating, semiconductor, or conductive material); and
selectively etching the wafer under the mask by using an etchant gas, wherein the etchant gas is selected from a group consisting of CF4 and NF3 (Paragraphs [0145-0146] openings are formed by an etching process that selectively etches to make the openings, and the etching process uses CF4 or NF3).
Togo fails to teach wherein the mask comprises an at least partially metallic material. Togo fails to explicitly teach that the mask is etched during the etching process.
Lin teaches methods related to etching features (Paragraph [0001]). Lin teaches the use of metal silicides as hard mask layers within a hard mask structure (Paragraph [0012] metal silicides can be used within a hard mask). Lin teaches that silicon containing layers within a hard mask structure can be etched during an etching process, acting as sacrificial layers that can result in improved feature profiles (Paragraph [0013]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Togo by selecting as a material for the hard mask a metal silicide as taught by Lin and causing the mask layer to be etched during the etching process.
One of ordinary skill in the art would have been motivated to make this selection because the use of a silicon-containing material, such as those taught by Lin, in the hard mask could have allowed for the mask layer to be etched during the etching process as a sacrificial material which would have allowed for improved feature profiles (Lin Paragraph [0013]). Additionally, it would be obvious to one of ordinary skill in the art to select as the hard mask material in the method of Togo a metal silicide as taught by Lin since metal silicides are known as hard mask materials 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.
Regarding Claim 13, Togo teaches wherein the wafer comprises an oxide containing material layer (Paragraphs [0145-0146] Figure 9 a substrate is provided that includes an alternating stack (elements 232 and 242) of layers that can be silicon oxide and silicon nitride).
Regarding Claim 14, Togo teaches wherein the oxide containing material layer comprises an oxide layer on a top of a nitride layer (Paragraphs [0145-0146] Figure 9 a substrate is provided that includes an alternating stack (elements 232 and 242) of layers that can be silicon oxide and silicon nitride).
Regarding Claim 15, Togo teaches wherein the oxide containing material layer comprises a stack of alternate oxide and nitride layers on top of each other (Paragraphs [0145-0146] Figure 9 a substrate is provided that includes an alternating stack (elements 232 and 242) of layers that can be silicon oxide and silicon nitride).
Regarding Claim 18, Togo further teaches wherein the etchant gas consists of CF4 (Paragraphs [0145-0146] openings are formed by an etching process that selectively etches to make the openings, and the etching process uses CF4).
Regarding Claim 20, Togo further teaches wherein the etchant gas consists of NF3 (Paragraphs [0145-0146] openings are formed by an etching process that selectively etches to make the openings, and the etching process uses NF3).
Claims 12 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Cai et al. (US20150287648-A1) in view of Tomura.
Regarding Claim 12, Cai teaches a method (Paragraph [0002] methods of forming devices taught) comprising:
forming a mask comprising at least a pattern on a wafer, (Paragraphs [0061-0063] Figures 22-23 hardmask layer (element 108) is formed into a pattern by the first etching process); and
selectively etching the wafer under the mask by using an etchant gas, wherein the etchant gas is selected from a group consisting of CF4 and NF3 (Paragraph [0063] second etching process is a dry etch that consists of CF4).
Cai fails to explicitly teach that the selective etching also etches the mask layer. However, Cai does teach that the hardmask layer is partial etched by the preceding etch processes (Paragraph [0065] “the remaining portions of the hardmask” are removed with later process steps).
Cai fails to teach wherein the mask comprises an at least partially metallic material, but teaches that the hardmask is not limited and can be made from various materials (Paragraph [0036]).
Tomura teaches a method of etching (Paragraph [0002]), that includes providing a patterned mask that can comprise tungsten (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) over an oxide layer (Paragraph [0026] substrate is provided that includes a silicon-containing film. Paragraph [0036] silicon-containing film can include silicon oxide film). Tomura teaches that during an etching process to etching the oxide layer the mask layer is etched (Paragraphs [0083-0084] the mask (element MK) and film (element SF) are etched by a process gas).
It would have been obvious to one of ordinary skill in the art to have modified the method of Cai by selecting as a mask material a tungsten containing mask material as taught by Tomura. Additionally it would have been obvious to modify the method such that the tungsten containing mask material was etched during the etching process, as taught by Tomura.
This modification would have been obvious to one of ordinary skill in the art because tungsten containing mask materials are taught as suitable hardmask materials by Tomura 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). The modification to etch the mask material during the etching process would have been obvious because Cai teaches that the mask material is etched during the etch steps taught in the methods of Cai and Tomura teaches that the mask material can be etched.
Regarding Claim 18, Cai further teaches wherein the etchant gas consists of CF4 NF3 (Paragraph [0063] second etching process is a dry etch that consists of CF4).
Response to Arguments
Applicant’s arguments, see Remarks Pg. 2-5, filed 08/21/2026, with respect to the 35 U.S.C. § 103 rejections have been fully considered.
Applicant’s argument with regards to the rejections of claims 18 and 20 citing Tomura in view of Cai and Tomura in view of Thedjoisworo have been considered and were persuasive. Accordingly, those specific rejections have been withdrawn and new rejections of those claims have been presented above.
Regarding the rejections of Claims 1 and 12 over Togo in view of Lin, applicant argues that Lin fails to teach the claimed limitations.
Examiner respectfully disagrees.
With regards to the limitation “a mask comprising at least a pattern on the surface”, Lin explicitly describes the silicon-containing layer as a hard mask layer. As applicant notes, this hard mask layer is taught to provide additional benefits to the hard mask stack and it would only be possible for the silicon-containing layer to be able to provide this benefit to the hard mask stack if it were formed into a pattern. Further, Lin explicitly teaches that the whole of the hard mask stack is formed into a pattern on the surface of the wafer (Paragraph [0066]). Examiner takes the position that if the one layer of the hard mask stack comprises a pattern on the surface of the wafer, as applicant agrees the ACL layer does, then every layer of the hard mask stack comprises a pattern on the surface of the wafer.
With regards to the limitation “selectively etching the mask”, applicant agrees that the silicon-containing mask is etched during the etching process. Examiner takes the position that the teachings of Lin that the silicon-containing layer is etching during the etching process meets the limitations as claimed.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW KEELAN LAOBAK whose telephone number is (703)756-5447. The examiner can normally be reached Monday - Friday 8:00am - 5:30pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Allen can be reached at 571-270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/A.K.L./Examiner, Art Unit 1713 /DUY VU N DEO/Primary Examiner, Art Unit 1713
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