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
The Applicants arguments presented on pages 5 and 6 of the response filed 07/23/2026 regarding the previous Restriction Requirement (mailed 06/01/2026) are convincing. The previous Restriction Requirement is withdrawn and claims 1 through 20 will be examined herein.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 07/15/2024, 03/24/2025, 10/25/2025, 12/09/2025 and 05/21/2026 are considered by the examiner.
It is noted that none of the foreign documents or non-patent literature documents cites on the IDS filed 07/15/2024 have copies provided in the file, however, copies of the references have been provided in the parent application, 17/814653, and therefore the cited references have been considered.
The information disclosure statement filed 03/24/2025 and 10/27/2025 fails to comply with 37 CFR 1.98(a)(3)(i) because it does not include a concise explanation of the relevance, as it is presently understood by the individual designated in 37 CFR 1.56(c) most knowledgeable about the content of the information, of each reference listed that is not in the English language. It has been placed in the application file, but the information referred to therein has not been considered.
Drawings
The drawings are objected to because reference number 406 in Figure 4 does not have an arrow or line pointing to a corresponding feature of the substrate processing system (see annotated figure below).
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Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
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.
Claims 1-12 and 15-20 are rejected under 35 U.S.C. 103 as being unpatentable over Chandrashekar et al. (US 2012/0015518; cited on IDS).
Regarding claims 1, 4, 5, 6 and 8, Chandrashekar et al. teaches a method of forming low resistivity tungsten films with good uniformity and adhesion for semiconductor fabrication (abstract, [0003]). In Figure 5, Chandrashekar et al. presents a cross section diagram of a film stack, including a titanium substrate layer (503; substrate) with a feature (opening) having a high aspect ratio or narrow width ([0022]), as shown in the figure reproduced below.
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The stack further comprises a titanium nitride layer (505; adhesion layer) on the titanium substrate layer (503; substrate) and a tungsten nucleation layer (507) disposed along the side walls of the feature having a high aspect ratio or narrow width ([0023-0026, 0031-0033, 0078]). The stack further comprises a tungsten bulk layer (509; fill layer) disposed over the tungsten nucleation layer (507) within the opening ([0031-0032, 0078]). Chandrashekar et al. further teaches that the tungsten nucleation layer (507) is formed by alternatingly applying a reducing agent, such as diborane, and a tungsten containing precursor such as WF6, which would thus result in a nucleation layer comprises both boron and tungsten ([0022-0023]).
Chandrashekar et al. teaches that the bulk tungsten can be deposited to any thickness, however the total tungsten thickness (nucleation + bulk tungsten) is typically no more than 600 Å, resulting in a resistivity of less than about 14mΩ-cm, and in certain cases less than about 11 mΩ-cm ([0032]).
Chandrashekar et al. does not expressly teach that the thickness of the tungsten containing layer is half a width of the tungsten containing layer disposed within the opening between the opposing sidewall portions of the opening, however, such a modification would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention. Chandrashekar et al. teaches that the bulk tungsten can be deposited to any thickness between 20 and 1000 Å and a resistivity of no greater than about 30 mΩ-cm, further teaching that the film typically has a no more than 600 Å, resulting in a resistivity of less than about 14mΩ-cm ([0032]). Therefore, it would have been obvious to one of ordinary skill in the art to modify the thickness as based upon the desired resistivity.
Regarding claims 2 and 3, Chandrashekar et al. teaches all the limitations of claim 1 above, and further teaches that the tungsten nucleation layer (507) is formed by alternatingly applying a reducing agent, such as diborane, and a tungsten containing precursor such as WF6 ([0022-0023]). Chandrashekar et al. teaches that efficient tungsten deposition processes that require tungsten nucleation layers typically have higher resistivities, thus, in order to form a low resistivity film, the nucleation layer should be kept as thin as possible but sufficiently thick to fully cover the underlying layer to support high quality bulk distribution of the tungsten bulk layer ([0018-0023]). Reducing agents, such as diborane, are important in the formation of the nucleation layer in order to reduce the overall stack resistivity ([0020-0021]).
While the reference does not expressly teach that the ratio of boron to tungsten in the nucleation layer is between about 1:4 to 1:1 as recited by claim 2 or between 1:3 to 1:2 as recited by claim 3, such a modification would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention based on the teachings of Chandrashekar et al. The reference teaches that reducing the nucleation layer is required to reduce the overall stack resistivity, therefore, it would have been obvious to one of ordinary skill in the art to modify the formation of the nucleation layer by to have as many desired alternating applications of reducing agent, such as diborane, and tungsten containing precursor such as WF6 ([0018-0023]), based on the desired resistivity such that the ratio of boron to tungsten falls within the claimed ranges.
Regarding claim 7, Chandrashekar et al. teaches all the limitations of claim 1 above, and further teaches that the feature has a high aspect ratio opening between the ranges of 5:1 to 30:1, and in certain embodiments from 10:1 to 20:1 ([0022]), both of which overlap the claimed range of 3:1 to 10:1. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exits.
Regarding claims 9, 10 and 11, Chandrashekar et al. teaches a method of forming low resistivity tungsten films with good uniformity and adhesion for semiconductor fabrication (abstract, [0003]). In Figure 5, Chandrashekar et al. presents a cross section diagram of a film stack, including a titanium substrate layer (503; substrate) with a feature (opening) having a high aspect ratio or narrow width ([0022]), as shown in the figure reproduced below.
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The stack further comprises a titanium nitride layer (505; adhesion layer) disposed on the sidewalls of the feature (opening) within the titanium substrate layer (503; substrate) and a tungsten nucleation layer (507) disposed on the titanium nitride layer (505; adhesion layer) along the side walls of the feature having a high aspect ratio or narrow width ([0023-0026, 0031-0033, 0078]). The stack further comprises a tungsten bulk layer (509; fill layer) disposed over the tungsten nucleation layer (507) within the opening ([0031-0032, 0078]). Chandrashekar et al. further teaches that the tungsten nucleation layer (507) is formed by alternatingly applying a reducing agent, such as diborane, and a tungsten containing precursor such as WF6, which would thus result in a nucleation layer comprises both boron and tungsten ([0022-0023]).
Chandrashekar et al. teaches that the bulk tungsten can be deposited to any thickness, however the total tungsten thickness (nucleation + bulk tungsten) is typically no more than 600 Å, resulting in a resistivity of less than about 14mΩ-cm, and in certain cases less than about 11 mΩ-cm ([0032]).
Chandrashekar et al. does not expressly teach that the thickness of the tungsten containing layer is half a width of the tungsten containing layer disposed within the opening between the opposing sidewall portions of the opening, however, such a modification would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention. Chandrashekar et al. teaches that the bulk tungsten can be deposited to any thickness between 20 and 1000 Å and a resistivity of no greater than about 30 mΩ-cm, further teaching that the film typically has a no more than 600 Å, resulting in a resistivity of less than about 14mΩ-cm ([0032]). Therefore, it would have been obvious to one of ordinary skill in the art to modify the thickness as based upon the desired resistivity.
Regarding claim 12, Chandrashekar et al. teaches all the limitations of claim 9 above, and further teaches that the tungsten nucleation layer (507) is formed by alternatingly applying a reducing agent, such as diborane, and a tungsten containing precursor such as WF6 ([0022-0023]). Chandrashekar et al. teaches that efficient tungsten deposition processes that require tungsten nucleation layers typically have higher resistivities, thus, in order to form a low resistivity film, the nucleation layer should be kept as thin as possible but sufficiently thick to fully cover the underlying layer to support high quality bulk distribution of the tungsten bulk layer ([0018-0023]). Reducing agents, such as diborane, are important in the formation of the nucleation layer in order to reduce the overall stack resistivity ([0020-0021]).
While the reference does not expressly teach that the ratio of boron to tungsten in the nucleation layer is between about 1:4 to 1:1 as recited by claim 10, such a modification would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention based on the teachings of Chandrashekar et al. The reference teaches that reducing the nucleation layer is required to reduce the overall stack resistivity, therefore, it would have been obvious to one of ordinary skill in the art to modify the formation of the nucleation layer by to have as many desired alternating applications of reducing agent, such as diborane, and tungsten containing precursor such as WF6 ([0018-0023]), based on the desired resistivity such that the ratio of boron to tungsten falls within the claimed ranges.
Regarding claim 15, 16, 17, 18, 19 and 20, Chandrashekar et al. teaches a method of forming low resistivity tungsten films with good uniformity and adhesion for semiconductor fabrication (abstract, [0003]). In Figure 5, Chandrashekar et al. presents a cross section diagram of a film stack, including a titanium substrate layer (503; substrate) with a feature (opening) having a high aspect ratio or narrow width ([0022]), as shown in the figure reproduced below.
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The stack further comprises a titanium nitride layer (505; adhesion layer) on the titanium substrate layer (503; substrate) and a tungsten nucleation layer (507) disposed along the side walls of the feature (opening) having a high aspect ratio or narrow width ([0023-0026, 0031-0033, 0078]). The stack further comprises a tungsten bulk layer (509; fill layer) disposed over the tungsten nucleation layer (507) within the opening ([0031-0032, 0078]). Chandrashekar et al. further teaches that the tungsten nucleation layer (507) is formed by alternatingly applying a reducing agent, such as diborane, and a tungsten containing precursor such as WF6, which would thus result in a nucleation layer comprises both boron and tungsten ([0022-0023]). Chandrashekar et al. teaches that efficient tungsten deposition processes that require tungsten nucleation layers typically have higher resistivities, thus, in order to form a low resistivity film, the nucleation layer should be kept as thin as possible but sufficiently thick to fully cover the underlying layer to support high quality bulk distribution of the tungsten bulk layer ([0018-0023]). Reducing agents, such as diborane, are important in the formation of the nucleation layer in order to reduce the overall stack resistivity ([0020-0021]).
While the reference does not expressly teach that the ratio of boron to tungsten in the nucleation layer is between about 1:4 to 1:1 as recited by claim 15 or between 1:3 to 1:2 as recited by claim 16, such a modification would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention based on the teachings of Chandrashekar et al. The reference teaches that reducing the nucleation layer is required to reduce the overall stack resistivity, therefore, it would have been obvious to one of ordinary skill in the art to modify the formation of the nucleation layer by to have as many desired alternating applications of reducing agent, such as diborane, and tungsten containing precursor such as WF6 ([0018-0023]), based on the desired resistivity such that the ratio of boron to tungsten falls within the claimed ranges.
Chandrashekar et al. teaches that the bulk tungsten can be deposited to any thickness, however the total tungsten thickness (nucleation + bulk tungsten) is typically no more than 600 Å, resulting in a resistivity of less than about 14mΩ-cm, and in certain cases less than about 11 mΩ-cm ([0032]).
Chandrashekar et al. does not expressly teach that the thickness of the tungsten containing layer is half a width of the tungsten containing layer disposed within the opening between the opposing sidewall portions of the opening, however, such a modification would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention. Chandrashekar et al. teaches that the bulk tungsten can be deposited to any thickness between 20 and 1000 Å and a resistivity of no greater than about 30 mΩ-cm, further teaching that the film typically has a no more than 600 Å, resulting in a resistivity of less than about 14mΩ-cm ([0032]). Therefore, it would have been obvious to one of ordinary skill in the art to modify the thickness as based upon the desired resistivity.
Claims 13 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Chandrashekar et al. (US 2012/0015518; cited on IDS) in view of Roy et al. (US 2017/0372953).
Regarding claims 13 and 14, Chandrashekar et al. teaches all the limitations of claim 9 above, however, the reference does not expressly teach that the surface roughness of the tungsten containing layer is 3.5nm or less as required by claim 13 or about 2nm to about 3 nm as requited by claim 14.
Roy et al. teaches a method of forming a metal layer for components in computer devices, wherein chemical vapor deposition of metal layers is known to have large grain size, high surface roughness and high tensile stress, which makes the metal layers prone to oxidation during subsequent oxide deposition process ([0004]). Roy et al. teaches that one method to reduce grain size and therefore surface roughness, is to deposit the metal layer on a seed layer, wherein the seed layer can be tungsten nitride and the metal layer is tungsten ([0024-0025]). Roy et al. further teaches an embodiment where in the metal layer is formed on a seed layer, and the resultant resistivity is less than about 30 mΩ-cm, and has a surface roughness less than about 1nm ([0030]).
Both Chandrashekar et al. and Roy et al. are in the field of metal components comprised of tungsten, therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to modify Chandrashekar et al. such that the surface roughness is less than about 1nm, as taught by Roy et al., as both references teach depositing a metal tungsten layer on a seed layer of tungsten.
Furthermore, the use of “about” with respect to the claimed ranges is a relative term (see MPEP2173.05(b)(III)), and the disclosure does not provide any guidance or definition as to the scope or bounds “about” provides for the claimed ranges. It would have been obvious to one of ordinary skill in the art that “less than about 1nm” taught by Roy et al. would fall within the approximate lower end point range of “about 2nm” recited by claim 14.
Conclusion
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LAURA POWERS
Examiner
Art Unit 1785
/LAURA C POWERS/Primary Examiner, Art Unit 1785
