DETAILED ACTION
Claims 1-20 are pending before the Office for review.
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 § 103
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 (i.e., changing from AIA to pre-AIA ) 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 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 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.
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.
Claims 1-7, 9-11, 13, 16-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over JOY et al (U.S. Patent Application Publication 2021/0313192).
With regards to claim 1, Joy discloses a method of processing a substrate, the method comprising: forming a patterned hardmask layer (114) over a conductive layer (106) to be etched, the conductive layer (106) disposed over a substrate (102) (Figure 6B); and patterning the conductive layer using the patterned hardmask layer as an etch mask (Figure 6C) (Paragraphs [0024]-[0039], [0057]-[0064]).
Joy does not explicitly disclose performing a cyclic plasma etch process to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process comprising exposing the substrate to a first plasma comprising a halogen to etch the conductive layer, and exposing the substrate to a second plasma comprising a silicon-containing precursor to deposit a silicon-containing protective layer over a top surface of the patterned hardmask layer.
However Joy discloses a method of processing a substrate comprising flowing a react gas to initiate a plasma for etching the refractory metal and pulsing a passivation gas; wherein the passivant gas forms a passivating layer on the vertical surfaces and horizontal surfaces with a passivation layer wherein the reactant gas comprises a halogen such as chlorine and the passivation gas comprising a passivant such a silicon tetrachloride wherein the silicon tetrachloride easily decomposes in the plasma resulting in Si deposition and CL radicals (Paragraphs [0024]-[0040]) rendering obvious performing a cyclic plasma etch process to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process comprising exposing the substrate to a first plasma comprising a halogen to etch the conductive layer, and exposing the substrate to a second plasma comprising a silicon-containing precursor to deposit a silicon-containing protective layer over a top surface of the patterned hardmask layer.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the embodiment of Joy to include the cycle of plasma etching and passivation as rendered obvious by the general teachings of Joy because the reference of Joy teaches that the passivation allows for the etching of the refractory metal without eroding the hardmask layer (Paragraph [0034]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the cycle of plasma etching and passivation as rendered obvious by Joy. MPEP 2143D
With regards to claim 2, the modified teachings of Joy renders obvious wherein the conductive layer comprises a refractory metal. (Paragraph [0016], [0059]).
With regards to claim 3, the modified teaching of Joy renders obvious wherein the conductive layer comprises ruthenium or molybdenum. (Paragraph [0016], [0059]).
With regards to claim 4, the modified teachings of Joy renders obvious wherein the patterned hardmask layer comprises silicon oxide or silicon nitride. (Paragraph [0060])
With regards to claim 5, the modified teachings of Joy renders obvious wherein the silicon-containing precursor comprises silicon tetrachloride. (Paragraph [0024]).
With regards to claim 6, the modified teachings of Joy renders obvious wherein the first plasma comprises oxygen and chlorine. (Paragraph [0026]).
With regards to claim 7, the modified teachings of Joy renders obvious wherein an underlying liner layer (etch stop) comprising nitride underlies the conductive layer, and wherein, after the cyclic plasma etch process, a top surface of the underlying liner layer is exposed at the bottom of the recess. (Paragraphs [0039], [0061]).
With regards to claim 9, Joy discloses a method of processing a substrate, the method comprising: forming a patterned hardmask layer (114) over a conductive layer (106) to be etched, the conductive layer (106) disposed over a substrate (102) (Figure 6B); flowing a halogen-containing etch gas (chlorine) into a plasma processing chamber, the substrate being loaded in the plasma processing chamber (Paragraphs [0025]-[0027]); while flowing the halogen-containing etch gas, sustaining a plasma generated from the halogen-containing etch gas in the plasma processing chamber; etching the conductive layer using the patterned hardmask layer as an etch mask by exposing the substrate to the plasma; while flowing the halogen-containing gas, flowing a silicon-containing precursor (silicon tetrachloride) into the plasma processing chamber to modify a composition of the plasma, (Figure 6C) (Paragraphs [0024]-[0039], [0057]-[0064]).
Joy does not explicitly disclose depositing a silicon-containing layer over a top surface of the patterned hardmask layer by exposing the substrate to the modified plasma and repeating the etching and the depositing.
However Joy discloses a method of processing a substrate comprising flowing a react gas to initiate a plasma for etching the refractory metal and pulsing a passivation gas; wherein the passivant gas forms a passivating layer on the vertical surfaces and horizontal surfaces with a passivation layer wherein the reactant gas comprises a halogen such as chlorine and the passivation gas comprising a passivant such a silicon tetrachloride wherein the silicon tetrachloride easily decomposes in the plasma resulting in Si deposition and CL radicals (Paragraphs [0024]-[0040]) rendering obvious depositing a silicon-containing layer over a top surface of the patterned hardmask layer by exposing the substrate to the modified plasma and repeating the etching and the depositing.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the embodiment of Joy to include the cycle of plasma etching and passivation as rendered obvious by the general teachings of Joy because the reference of Joy teaches that the passivation allows for the etching of the refractory metal without eroding the hardmask layer (Paragraph [0034]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the cycle of plasma etching and passivation as rendered obvious by Joy. MPEP 2143D
With regards to claim 10, the modified teachings of Joy discloses wherein a cycle of etching and passivation are performed wherein the etching gas comprises an oxidizing gas comprising oxygen which reacts with the surface (Paragraphs [0025]-[0033]) which renders obvious after depositing the silicon-containing layer, oxidizing the silicon-containing layer.
With regards to claim 11, the modified teachings of Joy renders obvious wherein the pattern forms 10nm nodes which uses less than 40nm pitches (Paragraph [0003]) which renders obvious wherein the patterned hardmask layer defines a line pattern having a pitch size between 10 nm and 50 nm, the line pattern being transferred to the conductive layer by the etching (Paragraphs [0023], [0058]-[0070]). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
With regards to claim 13, the modified teachings of Joy renders obvious wherein the conductive layer comprises ruthenium (Paragraphs [0016], [0059]), and wherein the halogen-containing etch gas comprising dichlorine and dioxygen. (Paragraphs [0026], [0037])
With regards to claim 16, Joy discloses a method of processing a substrate, the method comprising: forming a patterned hardmask layer (114) over a conductive layer (106) to be etched, the conductive layer (106) disposed over a substrate (102) (Figure 6B), the conductive layer comprising ruthenium (Paragraphs [0016], [0059]), the patterned hardmask layer comprising silicon (Paragraph [0060], discloses silicon nitride or silicon oxide), the substate comprising a etch stop layer (ESL) underlying the conductive layer (Paragraph [0061] discloses etch stop layer 104). (Paragraphs [0024]-[0039], [0057]-[0064] Figures 6A-6C).
Joy does not explicitly disclose patterning the conductive layer using the patterned hardmask layer as an etch mask, by performing a cyclic plasma etch process in a plasma processing chamber to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process comprising sustaining a plasma comprising an etchant, exposing the substrate to the plasma, the etchant etching the conductive layer, while the exposing, flowing a silicon-containing precursor to the plasma processing chamber to form a protective layer over a top surface of the patterned hardmask layer, and stopping the flow of silicon-containing precursor to stop the formation of the protective layer.
However Joy discloses a method of processing a substrate comprising flowing a react gas to initiate a plasma for etching the refractory metal and pulsing a passivation gas; wherein the passivant gas forms a passivating layer on the vertical surfaces and horizontal surfaces with a passivation layer wherein the reactant gas comprises a halogen such as chlorine and the passivation gas comprising a passivant such a silicon tetrachloride wherein the silicon tetrachloride easily decomposes in the plasma resulting in Si deposition and CL radicals; wherein the passivation is formed during the pulses and suspended between pulses and the reactant gas is consistently flowed (Paragraphs [0024]-[0043]) rendering obvious patterning the conductive layer using the patterned hardmask layer as an etch mask, by performing a cyclic plasma etch process in a plasma processing chamber to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process comprising sustaining a plasma comprising an etchant, exposing the substrate to the plasma, the etchant etching the conductive layer, while the exposing, flowing a silicon-containing precursor to the plasma processing chamber to form a protective layer over a top surface of the patterned hardmask layer, and stopping the flow of silicon-containing precursor to stop the formation of the protective layer.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the embodiment of Joy to include the cycle of plasma etching and passivation as rendered obvious by the general teachings of Joy because the reference of Joy teaches that the passivation allows for the etching of the refractory metal without eroding the hardmask layer (Paragraph [0034]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the cycle of plasma etching and passivation as rendered obvious by Joy. MPEP 2143D
With regards to claim 17, the modified teachings of Joy renders obvious wherein the etchant comprises a halogen (Paragraphs [0026], [0037]), and wherein the silicon-containing precursor comprises silicon tetrachloride (Paragraphs [0028], [0033]).
With regards to claim 18, the modified teachings of Joy renders obvious wherein, after performing the cyclic plasma etch process, a top surface of the ESL is exposed at the bottom of the recess (Paragraph [0070] Figure 6C), and at least a portion of the patterned hardmask layer (114) and a portion of the protective layer remain over the conductive layer. (Paragraphs [0028], [0034]-[0035], [0064], [0070]-[0071] discloses performing the etching and passivation formation until the etch stop layer is exposed; the hardmask layer and a portion of the passivation material on the conductive layer).
With regards to claim 20, the modified teachings of Joy discloses wherein the etching of the refractory metal is at a higher etch rate and a higher selectivity to adjacent materials (Paragraph [0016]) wherein the deposited protective layer is not readily etched (Paragraphs [0031]-[0034]). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) MPEP 2144.05(II)(A) Therefore it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to optimize the first etch rate of a conductive layer to amounts including Applicant’s claimed amount of a first etch rate to at least twice a second etch rate of a protective layer in order to etch the refractory metal at a higher etch rate and a higher selectivity to adjacent materials (Paragraph [0016]) including the deposited protective layer which is not readily etched as taught by the modified teachings of Joy (Paragraphs [0031]-[0034], MPEP 2144.05(II)(A)). Therefore the modified teachings of Joy renders obvious wherein the etchant etches the conductive layer at a first etch rate and the protective layer at a second etch rate, and wherein the first etch rate is at least twice the second etch rate.
Claims 8, 12 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over JOY et al (U.S. Patent Application Publication 2021/0313192), as applied to claims 1-7, 9-11, 13, 16-18 and 20, in further view of CHANG et al (U.S. Patent Application Publication 2021/0391181).
With regards to claim 8, the modified teachings of Joy renders obvious the limitations of claim 1.
However the modified teachings of Joy are silent as to wherein the recess has an aspect ratio between 3:1 and 6:1 after the cyclic plasma etch process.
Chang discloses a method of processing a substrate for fabricating an integrated circuit comprising metal lines using a patterned mask on an underlying layer wherein the patters has a width of 70nm to about 250nm and depth of about 200nm to about 4 microns (thickness of underlying layer 114) (Paragraphs [0014], [0027]-[0033]) which renders obvious wherein the recess has an aspect ratio between 3:1 and 6:1 after the cyclic plasma etch process. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to further modify the modified teachings of Joy to include the aspect ratios as rendered obvious by Chang because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired pattered substrate using the aspect ratios as rendered obvious by Chang. MPEP 2143D
With regards to claim 12, the modified teachings of Joy renders obvious the limitations of claim 9 as previously discussed.
However the modified teachings of Joy does not explicitly disclose wherein, prior to the etching, the patterned hardmask layer has a first thickness and the conductive layer has a second thickness, the second thickness is at least twice the first thickness.
Chang discloses a method of processing a substrate for fabricating an integrated circuit comprising metal lines using a patterned mask on an underlying layer wherein the underlaying layer to be etched has a thickness of approximately 200nm to approximately 4 microns and wherein the intermediate layer has a thickens of approximately 120nm to 300 nm (Paragraphs [0014], [0027]-[0033]) which renders obvious wherein, prior to the etching, the patterned hardmask layer has a first thickness and the conductive layer has a second thickness, the second thickness is at least twice the first thickness. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to further modify the modified teachings of Joy to include the layer thicknesses as rendered obvious by Chang because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired pattered substrate using the layer thicknesses as rendered obvious by Chang. MPEP 2143D
With regards to claim 19, the modified teachings of Joy renders obvious the limitations of claim 16 as previously discussed.
However the modified teachings of Joy does not explicitly disclose wherein each cycle of the cyclic plasma etch process is between 10 sec and 60 sec.
Chang discloses a method of processing a substrate for fabricating an integrated circuit comprising metal lines using a patterned mask on an underlying layer wherein the underlaying layer to be etched etch using a cycle of etching and depositing a protection layer wherein the etch time can be amounts such as 60 seconds (Paragraphs [0014], [0027]-[0033], [0050]-[0053], [0071]-[0072]) which renders obvious wherein each cycle of the cyclic plasma etch process is between 10 sec and 60 sec. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to further modify the modified teachings of Joy to include the etching duration as rendered obvious by Chang because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired pattered substrate using the etching duration as rendered obvious by Chang. MPEP 2143D
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over JOY et al (U.S. Patent Application Publication 2021/0313192), as applied to claims 1-7, 9-11, 13, 16-18 and 20, in further view of CHIANG et al (U.S. Patent Application Publication 20230049714).
With regards to claim 14, the modified teachings Joy renders obvious the limitations of claim 9 as previously discussed.
However the modified teachings of Joy are silent as to wherein the conductive layer comprises tungsten silicide or tungsten silicon nitride, and wherein the halogen-containing etch gas comprising dichlorine and dinitrogen.
Chiang discloses a method of processing a substrate for fabricating an integrated circuit comprising metal lines using a patterned mask on an tungsten silicide layer wherein the tungsten silicide layer is etched using a processing gas comprising dichlorine and dinitrogen (Paragraphs [0002], [0024]-[0027], [0040]) which renders obvious wherein the conductive layer comprises tungsten silicide, and wherein the halogen-containing etch gas comprising dichlorine and dinitrogen.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to further modify the modified teachings of Joy to include the tungsten silicide layer and etching gas as rendered obvious by Chiang because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired pattered substrate using the tungsten silicide layer and etching gas as rendered obvious by Chiang. MPEP 2143D
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over JOY et al (U.S. Patent Application Publication 2021/0313192), as applied to claims 1-7, 9-11, 13, 16-18 and 20 in further view of FUNG et al (U.S. Patent Application Publication 2022/0059365).
With regards to claim 15, the modified teachings Joy renders obvious the limitations of claim 9 as previously discussed and wherein the conductive layer comprises molybdenum, and wherein the halogen-containing etch gas comprising dichlorine, and dioxygen. (Paragraphs [0016], [0026], [0037])
However the modified teachings of Joy are silent as to wherein halogen containing etch gas comprises tetrafluoromethane.
Fung discloses a method of processing a substrate comprising etching a layer of molybdenum with a fluorine containing etching gas including CF4 (Paragraphs [0041]) which renders obvious wherein halogen containing etch gas comprises tetrafluoromethane.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to further modify the modified teachings of Joy to include the tetrafluoromethane as rendered obvious by Fung because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictable achieving the desired pattered substrate using the tetrafluoromethane as rendered obvious by Fung. MPEP 2143D
Conclusion
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/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713