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 with traverse of Method Embodiment 1 in the reply filed on 03/09/2026 is acknowledged. The traversal is on the ground(s) that the inventions as claimed are shown to be independent or distinct. Applicant’s arguments against the species restriction are found persuasive because during the Examiner’s search for Method Embodiment 1, the limitations of claims directed to Method Embodiment 2 were discovered. Therefore Examiner withdraws the species election of the Election/Restriction office action mailed on 01/13/2026.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the limitation of “the feature extending a depth from the substrate surface to a bottom” of the 4th line of the claim 1 must be shown or the feature(s) canceled from the claim(s). Examiner notes in Fig 2A that currently only a depth D of the 5th line of Claim 1 is shown. No new matter should be entered.
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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 1 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Regarding Claim 1, the limitation of “the feature extending a depth from the substrate surface to a bottom” is recited in the 4th line of the claim and the limitation “the feature having a depth D” is recited in the 5th line of the claim. Referencing the specification of the instant application Examiner notes that Fig 2A discloses that depth D extends from the substrate surface to the bottom of the feature. So it is unclear if “the feature extending a depth from the substrate surface to a bottom” is the same feature or a different feature of the claim as the “the feature having a depth D”. For purposes of Examination, Examiner interprets the limitation “the feature extending a depth from the substrate surface to a bottom” as “the feature extending a depth D from the substrate surface to a bottom” and the limitation “the feature having a depth D” as “the feature having the depth D”.
Claim 14 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Regarding Claim 14, it cites the limitation “wherein the nucleation underlayer does not increase a resistance of the metal liner and the metal gapfill”. It is unclear as to what the recited claim limitation “not increased resistance” is relative too. Further the instant application, in Fig 2D, discloses elements metal liner 230 and gapfill 240 do not have a nucleation underlayer between them. So it is unclear how the recited limitation “wherein the nucleation underlayer does not increase a resistance of the metal liner and the metal gapfill” further defines the metes and bounds of the invention. Further the presence of the nucleation underlayer, where it contacts the metal liner and where it contacts the metal gapfill, as shown in Fig 2D of the instant application, will inherently impact some influence on adhesion. For purposes of examination, Examiner interprets the limitation “does not adversely affect” as “provides”.
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.
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Claims 1-14 and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Guan et al. (US 2014/0073135 A1, hereinafter Guan ‘135) in view of Chandrashekar et al. (US 8058170 B2, hereinafter Chandrashekar ‘170) and in further view of Drewery et al. (US 6,790,773 B1, hereinafter Drewery ‘773), in view of the following arguments.
With respect to Claim 1 Guan ‘135 discloses a method of metal gapfill (Fig 1-7), the method comprising:
exposing a substrate surface (substrate disclosed in Para [0032]) to a nucleation presoak (Step 301, Fig 3, Para [0034]) to form a nucleation underlayer (nucleation underlayer of Step 301 formation disclosed in Para [0034]),
depositing (Step 305) a metal liner (metal liner of Step 305, Fig 3, Para [0040], discloses step does not entirely fill feature (Para [0040] discloses “substantially fills”)) on the nucleation underlayer (nucleation underlayer of Step 301); and
depositing (Step 307) a metal gapfill (metal gapfill of Step 307, Fig 3, Para [0041]) on the metal liner (metal liner of Step 305) and the nucleation underlayer (nucleation underlayer of Step 301).
But Guan ‘135 fails to explicitly disclose a substrate with at least one feature therein, the feature extending a depth from the substrate surface to a bottom and having two sidewalls, the feature having a depth D and a width W defining an aspect ratio D:W.
Nevertheless, in a related endeavor (Fig 1-7 of Chandrashekar ‘170), Chandrashekar ‘170 teaches a substrate with at least one feature therein (103, Fig 1 of Chandrashekar ‘170, Col 3, Line 36 and Col 4, Lines 9-11), the feature (103) extending a depth (Note above interpretation; Examiner interprets the limitation “the feature extending a depth from the substrate surface to a bottom” as “the feature extending a depth D from the substrate surface to a bottom”) (depth as shown in annotated Fig 1 of Chandrashekar ‘170, hereinafter depth D) from the substrate surface (top of substrate as disclosed in annotated Fig 1 of Chandrashekar ‘170) to a bottom (bottom of feature as disclosed in annotated Fig 1 of Chandrashekar ‘170) and having two sidewalls (sidewalls of 103 as disclosed in annotated Fig 1 of Chandrashekar ‘170), the feature (103) having a depth D (Note above interpretation; Examiner interprets the limitation “the feature having a depth D” as “the feature having the depth D”) (depth D as shown in annotated Fig 1 of Chandrashekar ‘170) and a width W (W2, Fig 1, Col 3, Line 40 of Chandrashekar ‘170) defining an aspect ratio D:W (depth D:W2, Col 4, Lines 9-11 disclose a depth to width of 103 as an aspect ratio).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s teaching of a substrate with at least one feature therein, the feature extending a depth D from the substrate surface to a bottom and having two sidewalls, the feature having the depth D and a width W defining an aspect ratio D:W into Guan ‘135’s method. Guan ‘135 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an metal formation. Chandrashekar ‘170 further teaches filling high aspect ratio features and provides details of that feature. Therefore the ordinary artisan would have been motivated to modify Guan ‘135 with the substrate features in the manner set forth above, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for process details, and Chandrashekar ‘170 teaches that a nucleation underlayer method can reduce resistivity in high aspect ratio features.
As incorporated, the substrate feature (103 of Chandrashekar ‘170) extending a depth from the substrate surface to a bottom and having two sidewalls, the feature having a depth D and a width W defining an aspect ratio D:W would be used in the substrate of Guan ‘135 so that the nucleation underlayer (nucleation underlayer of Step 301), the metal liner (metal liner of Step 305) and metal gapfill (metal gapfill of Step 307) of Guan ‘135 are formed in feature 103 of Chandrashekar ‘170.
But Guan ‘135 as modified by Chandrashekar ‘170 fails to explicitly disclose depositing a metal liner by physical vapor deposition (PVD).
However, in a related endeavor, (Fig 3A-3C of Drewery ‘773), Drewery ‘773 teaches depositing a metal liner (300, Fig 3A of Drewery ‘773, Col 7, Lines 35-37) by physical vapor deposition (PVD) (PVD process disclosed in Col 7, Lines 49-51).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Drewery ‘773’s teaching of depositing a metal liner by physical vapor deposition (PVD) into Guan ‘135 as modified by Chandrashekar ‘170’s method. Guan ‘135 as modified by Chandrashekar ‘170 teaches a method to partially fill a feature. Drewery ‘773 teaches an interconnect and a process to partially fill the interconnect with a conductive material. The PNL process taught by Guan ‘135 and the PVD process taught by Drewery ‘773 are both well-known processes for filling features with conductive material. The person having ordinary skill in the art would therefore have a reasonable expectation of success in using the PVD process of Drewery ‘773 to partially fill the feature of Guan ‘135 as modified by Chandrashekar ‘170 and would be motivated to use PVD because of the low process temperature and low process costs a PVD process can provide.
Therefore the ordinary artisan would have been motivated to incorporate the PVD process taught by Drewery ‘773 as the process to deposit the metal liner (metal liner of Step 305) of Guan ‘135 as modified by Chandrashekar ‘170.
With respect to Claim 2 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses further wherein the aspect ratio (depth D:W2 of 103 as shown in annotated Fig 1 of Chandrashekar ‘170) of the at least one feature (103 of Chandrashekar ‘170 as incorporated in Guan ‘135 as described above) is at least 5:1. (Chandrashekar ‘170 disclose 103 having an aspect ratio of 5:1-30:1 in Col 4, Line 9-11).
With respect to Claim 3 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 discloses further wherein the metal liner (metal liner of Step 305) and the metal gapfill (metal gapfill of Step 307) comprise tungsten (Para [0021] discloses process of Guan ‘135 teaches method to deposit tungsten films and layers in a structure).
With respect to Claim 4 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 discloses further wherein the nucleation presoak (Step 301) comprises a silicon compound (Para [0034] discloses using silane for nucleation process).
With respect to Claim 5 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 4, and Guan ‘135 discloses further wherein the nucleation presoak (Step 301) consists essentially of silane (SiH4) (Para [0034] discloses using silane (“…instead of alternating boron-containing reducing agent…”) for nucleation process).
With respect to Claim 6 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 discloses further wherein the nucleation presoak (Step 301) comprises a boron compound (Para [0034] discloses using boron containing agents for nucleation process).
With respect to Claim 7 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 6, and Guan ‘135 discloses further wherein the nucleation presoak (Step 301) consists essentially of diborane (B2H6) (Para [0034] discloses using diborane for nucleation process).
With respect to Claim 8 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Chandrashekar ‘170 further teaches wherein the nucleation underlayer (nucleation, Fig 1 of Chandrashekar ‘170, Col 2, Lines 46-50) comprises 1- 2 monolayers of silicon and/or boron (Col 2, Lines 46-50 of Chandrashekar ‘170 teaches the nucleation process comprised depositing > 1 monolayer per cycle and Col 4, Lines 37-40 discloses silicon and/or boron as materials of nucleation underlayer).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s further teaching of wherein the nucleation underlayer comprises 1- 2 monolayers of silicon and/or boron into Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773’s method. Guan ‘135 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an metal formation. Therefore the ordinary artisan would have been motivated to further modify Guan ‘135 as modified by Chandrashekar ‘170 in the manner set forth above, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for nucleation process details, and Chandrashekar ‘170 teaches in Col 2, Lines 62-65 that the nucleation method results in “…good plugfill, have low resistivity and exhibit good micro-adhesion”.
As incorporated, the nucleation process taught by Chandrashekar ‘170 wherein the nucleation underlayer comprises 1-2 monolayers of silicon and/or boron in the nucleation process (Step 301 of Guan ‘135) in the method of Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773.
With respect to Claim 9 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, but Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 fails to explicitly disclose wherein the metal liner has an average thickness on the substrate surface outside of the at least one feature of about 50 Å.
Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 fails to expressly disclose wherein the metal liner has an average thickness on the substrate surface outside of the at least one feature of about 50 Å. However, the examiner notes that the applicants disclosure, in Para [0035], teaches wherein the recited thickness has the advantage of preventing the nucleation underlayer from forming high resistance in the feature. Having this mind, Drewery ‘773 teaches a metal liner (300) with a thickness of 10 nm (100Å)(Col 7, Lines 48-50 of Drewery ‘773 discloses a tungsten metal layer of 10nm(100Å). Therefore, it would have been obvious to a person of ordinary skill in the art to arrive at the recited limitation through routine optimization, to obtain the well-known advantage of preventing the nucleation underlayer from forming high resistance in the feature. See MPEP§2144.05 (II)(A),(B).
With respect to Claim 10 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 discloses an embodiment wherein the metal gapfill (metal gapfill of Step 307) is deposited by atomic layer deposition (ALD) (Para [0036] discloses bulk metal gapfill can be deposited by ALD).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Guan ‘135’s further teaching of wherein the metal gapfill is deposited by atomic layer deposition (ALD) into Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773’s method. Therefore the ordinary artisan would have been motivated to modify Guan ‘135 with the ALD process to deposit the metal gapfill by atomic layer deposition (ALD) in the manner set forth above, at least, because a ALD, CVD and PNL are well-known processes for metal deposition; therefore the person of ordinary skill in the art would have a reasonable expectation of success in using the ALD process and because of the well-known advantage of ALD depositing a uniform thin layer which would provide a precise metal gapfill method.
With respect to Claim 11 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 discloses further wherein the metal gapfill (metal gapfill of Step 307) is deposited by chemical vapor deposition (CVD) (Fig 3 and Para [0040] disclose a CVD process for the metal gapfill Step 307).
With respect to Claim 12 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Guan ‘135 as modified by Chandrashekar ‘170 further discloses wherein the metal gapfill (metal gapfill of Step 307) is formed directly on the metal liner (metal liner of Step 305 as modified by Chandrashekar ‘170 as described above)
But Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 does not explicitly disclose wherein the metal gapfill is formed directly on the nucleation underlayer
However, Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 teaches the metal liner does not entirely fill the feature (Para [0040] of Guan ‘135, discloses step 305 does not entirely fill feature (Para [0040] discloses “substantially fills”)).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, that the metal gapfill (metal gapfill of Step 307) is formed directly on the nucleation underlayer (nucleation underlayer of Step 301)(Para [0041] discloses metal of gapfill of Step 307 being formed on metal liner of Step 305 and nucleation underlayer of Step 301. Para [0040], discloses step does not entirely fill feature (Para [0040] discloses “substantially fills”).
Therefore, as Fig 1 of Chandrashekar ‘170 shows, the feature (103 of Chandrashekar ‘170 as incorporated in Guan 135 as described above) shows the nucleation liner covers the entire sidewalls of 103, so if the metal liner does not fill the entire feature the nucleation feature would be exposed in the region were the metal liner is not present and therefore it would be obvious that the metal gapfill will form directly on the nucleation underlayer in the regions where they metal liner has not filled the feature.
With respect to Claim 13 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, but Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 does not explicitly disclose wherein the nucleation underlayer does not increase a resistance of the metal liner and the metal gapfill.
However, Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 teaches the nucleation monolayer is below the interface of the metal line and the metal gapfill, as described above. Therefore, it would be obvious to one of ordinary skill in the art that the nucleation underlayer would not be involved in the electrical resistance between the metal line and the metal gapfill and therefore it would be obvious to a person of ordinary skill in the art that the nucleation underlayer of Guan ‘135 as modified by Chandrashekar ‘170 does not increase a resistance of the metal liner and the metal gapfill Guan ‘135 as modified by Chandrashekar ‘170.
With respect to Claim 14 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 1, and Chandrashekar ‘170 further discloses wherein the nucleation underlayer (nucleation underlayer of Step 203, Fig 2 of Chandrashekar ‘170, Col 4, Lines 22-24) does not adversely affect (Note Examiner’s interpretation of “does not adversely affect” as “provides”) adhesion of the metal liner and metal gapfill (Step 207, Fig 2 of Chandrashekar ‘170, Col 2, Lines 62-65 discloses process of nucleation underlayer provides good micro-adhesion).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s further teaching of wherein the nucleation underlayer provides adhesion of the metal liner and metal gapfill into Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773’s method. Guan ‘135 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an metal formation. Therefore the ordinary artisan would have been motivated to further modify Guan ‘135 as modified by Chandrashekar ‘170 with the nucleation layer method in the manner set forth above, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for nucleation process details, and Chandrashekar ‘170 teaches in Col 2, Lines 62-65 that the nucleation method “…exhibit good micro-adhesion”.
As incorporated, the nucleation process taught by Chandrashekar ‘170 wherein the nucleation underlayer provides adhesion of the metal liner and metal gapfill in the nucleation process (Step 301 of Guan ‘135) in the method of Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773.
With respect to Claim 18 Guan ‘135 discloses a method of metal gapfill (Fig 1-7), the method comprising:
exposing a substrate surface (substrate disclosed in Para [0032]) to a nucleation presoak (Step 301, Fig 3, Para [0034]) comprising diborane (Para [0034] discloses using diborane for nucleation process) to form a boron nucleation underlayer (Para [0034] discloses diborane forming boron nucleation underlayer);
depositing (Step 305) a metal liner (metal liner of Step 305, Fig 3, Para [0040], discloses step does not entirely fill feature (Para [0040] discloses “substantially fills”)) comprising tungsten (Para [0021] discloses process of Guan ‘135 teaches method to deposit tungsten films and layers in a structure) on the boron nucleation underlayer(Para [0034] discloses diborane forming boron nucleation underlayer); and
depositing (Step 307) a metal gapfill (metal gapfill of Step 307, Fig 3, Para [0041]) comprising tungsten (Para [0021] discloses process of Guan ‘135 teaches method to deposit tungsten films and layers in a structure) on the metal liner (metal liner of Step 305) and the boron nucleation underlayer (Para [0034] discloses diborane forming boron nucleation underlayer).
But Guan ‘135 fails to explicitly disclose a substrate with at least on feature therein, the feature extending a depth from the substrate surface to a bottom and having two sidewalls.
Nevertheless, in a related endeavor (Fig 1-7 of Chandrashekar ‘170), Chandrashekar ‘170 teaches a substrate with at least one feature therein (103, Fig 1 of Chandrashekar ‘170, Col 3, Line 36 and Col 4, Lines 9-11), the feature (103) extending a depth (depth D as shown in annotated Fig 1 of Chandrashekar ‘170, hereinafter depth D) from the substrate surface (top of substrate as disclosed in annotated Fig 1 of Chandrashekar ‘170) to a bottom (bottom of feature as disclosed in annotated Fig 1 of Chandrashekar ‘170) and having two sidewalls (sidewalls of 103 as disclosed in annotated Fig 1 of Chandrashekar ‘170);
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s teaching of a substrate with at least one feature therein, a silicon nucleation underlayer, the feature extending a depth from the substrate surface to a bottom and having two sidewalls into Guan ‘135’s method. Guan ‘135 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar ‘170 for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an metal formation. Chandrashekar ‘170 further teaches filling high aspect ratio features and provides details of that feature. Therefore the ordinary artisan would have been motivated to modify Guan ‘135 with the substrate features in the manner set forth above, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for process details, and Chandrashekar ‘170 teaches that a nucleation underlayer method can reduce resistivity in high aspect ratio features.
As incorporated, the substrate feature (103 of Chandrashekar ‘170) extending a depth from the substrate surface to a bottom and having two sidewalls would be used in the substrate of Guan ‘135 so that the nucleation underlayer (nucleation underlayer of Step 301), the metal liner (metal liner of Step 305) and metal gapfill (metal gapfill of Step 307) of Guan ‘135 are formed in feature 103 of Chandrashekar ‘170.
But Guan ‘135 as modified by Chandrashekar ‘170 fails to explicitly disclose depositing a metal liner by physical vapor deposition (PVD).
However, in a related endeavor, (Fig 3A-3C of Drewery ‘773), Drewery ‘773 teaches depositing a metal liner (300, Fig 3A of Drewery ‘773, Col 7, Lines 35-37) by physical vapor deposition (PVD) (PVD process disclosed in Col 7, Lines 49-51).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Drewery ‘773’s teaching of depositing a metal liner by physical vapor deposition (PVD) into Guan ‘135 as modified by Chandrashekar ‘170’s method. Guan ‘135 as modified by Chandrashekar ‘170 teaches a method to partially fill a feature. Drewery ‘773 teaches an interconnect and a process to partially fill the interconnect with a conductive material. The PNL process taught by Guan ‘135 and the PVD process taught by Drewery ‘773 are both well-known processes for filling features with conductive material. The person having ordinary skill in the art would therefore have a reasonable expectation of success in using the PVD process of Drewery ‘773 to partially fill the feature of Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Desai ‘796 and would be motivated to use PVD because of the low process temperature and low process costs a PVD process can provide.
Therefore the ordinary artisan would have been motivated to incorporate the PVD process taught by Drewery ‘773 as the process to deposit the metal liner (metal liner of Step 305) of Guan ‘135 as modified by Chandrashekar ‘170.
With respect to Claim 19 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 18, and Chandrashekar ‘170 further teaches wherein the boron nucleation underlayer (nucleation, Fig 1 of Chandrashekar ‘170, Col 2, Lines 46-50) comprises 1- 2 monolayers of boron on average (Col 2, Lines 46-50 of Chandrashekar ‘170 teaches the nucleation process comprised depositing > 1 monolayer per cycle and Col 4, Lines 37-40 discloses boron as material of nucleation underlayer).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s further teaching of wherein the nucleation underlayer comprises 1- 2 monolayers of boron on average into Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773’s method. Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar ‘170 for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak and metal formation. Therefore the ordinary artisan would have been motivated to further modify Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for nucleation process details, and Chandrashekar ‘170 teaches in Col 2, Lines 62-65 that the nucleation method results in “…good plugfill, have low resistivity and exhibit good micro-adhesion”.
As incorporated, the nucleation process taught by Chandrashekar ‘170 wherein the nucleation underlayer comprises 1-2 monolayers of boron in the nucleation process (Step 301 of Guan ‘135) in the method of Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773.
With respect to Claim 20 Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 discloses all limitations of the method of claim 18, and Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 further discloses wherein the metal gapfill (metal gapfill of Step 307) is formed directly on the metal liner (metal liner of Step 305 as modified above),
But Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Drewery ‘773 does not explicitly disclose wherein the metal gapfill is formed directly on the boron nucleation underlayer
However, Guan ‘135 teaches the metal liner does not entirely fill the feature (Para [0040] of Guan ‘135, discloses step 305 does not entirely fill feature (Para [0040] discloses “substantially fills”)).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, that the metal gapfill (metal gapfill of Step 307) is formed directly on the boron nucleation underlayer (nucleation underlayer of Step 301 as modified above)(Para [0041] discloses metal of gapfill of Step 307 being formed on metal liner of Step 305 and nucleation underlayer of Step 301. Para [0040], discloses step does not entirely fill feature (Para [0040] discloses “substantially fills”).
Therefore, as Fig 1 of Chandrashekar ‘170 shows, the feature (103 of Chandrashekar ‘170 as incorporated in Guan 135 as described above) shows the nucleation liner covers the entire sidewalls of 103, so if the metal liner does not fill the entire feature the nucleation feature would be exposed in the region were the metal liner is not present and therefore it would be obvious that the metal gapfill will form directly on the nucleation underlayer in the regions where they metal liner has not filled the feature.
Claims 15-17 are rejected under 35 U.S.C. 103 as being unpatentable over Guan ‘135 in view of Chandrashekar ‘170 in view of Desai et al. (US 2002/0090796 A1, hereinafter Desai ‘796) and in further view of Drewery ‘773, in view of the following arguments.
With respect to Claim 15 Guan ‘135 discloses a method of metal gapfill (Fig 1-7), the method comprising:
exposing a substrate surface (substrate disclosed in Para [0032]) to a nucleation presoak (Step 301, Fig 3, Para [0034]) comprising silane (Para [0034] discloses using silane for nucleation process) to form nucleation underlayer (nucleation underlayer of Step 301 formation disclosed in Para [0034]),
depositing (Step 305) a metal liner (metal liner of Step 305, Fig 3, Para [0040], discloses step does not entirely fill feature (Para [0040] discloses “substantially fills”)) comprising tungsten (Para [0021] discloses process of Guan ‘135 teaches method to deposit tungsten films and layers in a structure) on the silicon nucleation underlayer (nucleation underlayer of Step 301); and
depositing (Step 307) a metal gapfill (metal gapfill of Step 307, Fig 3, Para [0041]) comprising tungsten (Para [0021] discloses process of Guan ‘135 teaches method to deposit tungsten films and layers in a structure) on the metal liner (metal liner of Step 305) and the nucleation underlayer (nucleation underlayer of Step 301).
But Guan ‘135 fails to explicitly disclose a substrate with at least one feature therein, the feature extending a depth from the substrate surface to a bottom and having two sidewalls;
Nevertheless, in a related endeavor (Fig 1-7 of Chandrashekar ‘170), Chandrashekar ‘170 teaches a substrate with at least one feature therein (103, Fig 1 of Chandrashekar ‘170, Col 3, Line 36 and Col 4, Lines 9-11), the feature (103) extending a depth (depth D as shown in annotated Fig 1 of Chandrashekar ‘170, hereinafter depth D) from the substrate surface (top of substrate as disclosed in annotated Fig 1 of Chandrashekar ‘170) to a bottom (bottom of feature as disclosed in annotated Fig 1 of Chandrashekar ‘170) and having two sidewalls (sidewalls of 103 as disclosed in annotated Fig 1 of Chandrashekar ‘170);
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s teaching of a substrate with at least one feature therein, a silicon nucleation underlayer, the feature extending a depth from the substrate surface to a bottom and having two sidewalls into Guan ‘135’s method. Guan ‘135 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an metal formation. Chandrashekar ‘170 further teaches filling high aspect ratio features and provides details of that feature. Therefore the ordinary artisan would have been motivated to modify Guan ‘135 with the substrate features in the manner set forth above, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for process details, and Chandrashekar ‘170 teaches that a nucleation underlayer method can reduce resistivity in high aspect ratio features.
As incorporated, the substrate feature (103 of Chandrashekar ‘170) extending a depth from the substrate surface to a bottom and having two sidewalls would be used in the substrate of Guan ‘135 so that the nucleation underlayer (nucleation underlayer of Step 301), the metal liner (metal liner of Step 305) and metal gapfill (metal gapfill of Step 307) of Guan ‘135 are formed in feature 103 of Chandrashekar ‘170.
Guan ‘135 as modified by Chandrashekar ‘170 fails to explicitly disclose a nucleation presoak comprising silane forms a silicon nucleation underlayer,
However, in a related endeavor (Fig 1-3 of Desai ‘796), Desai ‘796 teaches a nucleation presoak comprising silane (disclosed in Para [0036] of Desai ‘796) to form a silicon nucleation underlayer (30, Fig 2 of Desai ‘796, Para [0036]).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Desai ‘796’s teaching of a nucleation presoak comprising silane to form a silicon nucleation underlayer into Guan ‘135 as modified by Chandrashekar ‘170’s method. Guan ‘135 as modified by Chandrashekar ‘170 teaches a nucleation presoak comprising silane (as disclosed above) but does not explicitly state the end compositions of the presoak. Desai ‘796 teaches an interconnect and a process to fill the interconnect with a conductive material. Desai ‘796 further teaches that depositing a silane layer as part of a CVD process results in the creation of a silicon layer. The ordinary artisan, therefore, would have been motivated to modify Guan ‘135 as modified by Chandrashekar ‘170 in the manner set forth above, at least, because as Desai ‘796 teaches in Para [0002] forming this silicon layer from silane will increase the homogeneity of the electrically conductive material filling the plug.
As incorporated, the teaching of Desai ‘796 that a silane in a nucleation presoak would result in a silicon nucleation underlayer would be incorporated in the method of Guan ‘135 as modified by Chandrashekar ‘170 which would also result in the nucleation underlayer under the metal liner being a silicon nucleation underlayer.
But Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Desai ‘796 fails to explicitly disclose depositing a metal liner by physical vapor deposition (PVD).
However, in a related endeavor, (Fig 3A-3C of Drewery ‘773), Drewery ‘773 teaches depositing a metal liner (300, Fig 3A of Drewery ‘773, Col 7, Lines 35-37) by physical vapor deposition (PVD) (PVD process disclosed in Col 7, Lines 49-51).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Drewery ‘773’s teaching of depositing a metal liner by physical vapor deposition (PVD) into Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Desai ‘796’s method. Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Desai ‘796 teaches a method to partially fill a feature. Drewery ‘773 teaches an interconnect and a process to partially fill the interconnect with a conductive material. The PNL process taught by Guan ‘135 and the PVD process taught by Drewery ‘773 are both well-known processes for filling features with conductive material. The person having ordinary skill in the art would therefore have a reasonable expectation of success in using the PVD process of Drewery ‘773 to partially fill the feature of Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Desai ‘796 and would be motivated to use PVD because of the low process temperature and low process costs a PVD process can provide.
Therefore the ordinary artisan would have been motivated to incorporate the PVD process taught by Drewery ‘773 as the process to deposit the metal liner (metal liner of Step 305) of Guan ‘135 as modified by Chandrashekar ‘170 and further modified by Desai ‘796.
With respect to Claim 16 Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773 discloses all limitation of the method of claim 15, and Chandrashekar ‘170 further teaches wherein the nucleation underlayer (nucleation, Fig 1 of Chandrashekar ‘170, Col 2, Lines 46-50) comprises 1- 2 monolayers of silicon and/or boron (Col 2, Lines 46-50 of Chandrashekar ‘170 teaches the nucleation process comprised depositing > 1 monolayer per cycle and Col 4, Lines 37-40 discloses silicon and/or boron as materials of nucleation underlayer).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chandrashekar ‘170’s further teaching of wherein the nucleation underlayer comprises 1- 2 monolayers of silicon and/or boron into Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773’s method. Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773 teaches a method for forming a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an initial metal formation and a bulk metal formation. Guan ‘135 further directs the person of ordinary skill in the art to refer to Chandrashekar for further details on the disclosed process in Para [0034] of Guan ‘135. Referencing Chandrashekar ‘170 teaches a method to form a low resistivity metal feature in an interconnect structure that comprises a nucleation presoak, an metal formation. Therefore the ordinary artisan would have been motivated to further modify Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773, at least, because Guan ‘135 directs the person of ordinary skill in the art to Chandrashekar ‘170 for nucleation process details, and Chandrashekar ‘170 teaches in Col 2, Lines 62-65 that the nucleation method results in “…good plugfill, have low resistivity and exhibit good micro-adhesion”.
As incorporated, the nucleation process taught by Chandrashekar ‘170 wherein the nucleation underlayer comprises 1-2 monolayers of silicon in the nucleation process (Step 301 of Guan ‘135) in the method of Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773.
With respect to Claim 17 Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773 discloses all limitation of the method of claim 15, and Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773 further discloses wherein the metal gapfill (metal gapfill of Step 307) is formed directly on the metal liner (metal liner of Step 305 as modified above),
But Guan ‘135 as modified by Chandrashekar ‘170 as modified by Desai ‘796 and further modified by Drewery ‘773 does not explicitly disclose wherein the metal gapfill is formed directly on the silicon nucleation underlayer
However, Guan ‘135 teaches the metal liner does not entirely fill the feature (Para [0040] of Guan ‘135, discloses step 305 does not entirely fill feature (Para [0040] discloses “substantially fills”)).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, that the metal gapfill (metal gapfill of Step 307) is formed directly on the silicon nucleation underlayer (nucleation underlayer of Step 301 as modified above)(Para [0041] discloses metal of gapfill of Step 307 being formed on metal liner of Step 305 and nucleation underlayer of Step 301. Para [0040], discloses step does not entirely fill feature (Para [0040] discloses “substantially fills”).
Therefore, as Fig 1 of Chandrashekar ‘170 shows, the feature (103 of Chandrashekar ‘170 as incorporated in Guan 135 as described above) shows the nucleation liner covers the entire sidewalls of 103, so if the metal liner does not fill the entire feature the nucleation feature would be exposed in the region were the metal liner is not present and therefore it would be obvious that the metal gapfill will form directly on the nucleation underlayer in the regions where they metal liner has not filled the feature.
Conclusion
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/PAUL A BERRY/Examiner, Art Unit 2898 /JULIO J MALDONADO/Supervisory Patent Examiner, Art Unit 2898
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