DETAILED ACTION
Status of Claims
As of the amendment filed 12/22/25, no claims have been added or canceled, and claims 1, 2, 5-9, 11, and 14-19 have been amended. Therefore, claims 1-20 remain pending, with claims 1, 11, and 17 being independent.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 1-3, 5-7, and 11-15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Nag (US 2017/0213792).
As to claim 1, Nag teaches a method (figs. 1-5) comprising: forming a metal plug (24) having a top surface (32) formed with a seam (30, fig. 2, [0018] and [0020]); depositing a film (34) over the top surface of the metal plug and at least partially filling the seam (fig. 3); and removing the film from over the metal plug to uncover the top surface ([0022]), wherein a remaining portion of the film remains in the seam (fig. 3).
As to claim 2, Nag further teaches after removing the film from over the metal plug, depositing an etch stop layer (38) on the metal plug (24, fig. 4, [0023]); forming a layer of dielectric material (40) over the metal plug (fig. 4, [0023]); etching the layer of dielectric material over the metal plug to form a trench (46, fig. 4, [0025]); removing the etch stop layer from over the metal plug (fig. 4, [0025], the etch stop layer is removed when forming the trench); and depositing a conductive material (56) in the trench to form a conductive interconnect in contact with the metal plug (fig. 5, [0027]).
As to claim 3, Nag further teaches the film (34) is an oxide, nitride, oxynitride, or metal layer ([0022]).
As to claim 5, Nag further teaches forming a conductive interconnect (56) directly on the top surface of the metal plug (24) and directly on the remaining portion of the film (34, fig. 5, [0027]).
As to claim 6, Nag further teaches forming a conductive interconnect (56) directly on the top surface of the metal plug (24) and directly on the remaining portion of the film (34, fig. 5), wherein the conductive interconnection (54) comprises a barrier layer (52) directly on the top surface of the metal plug (24) and directly on the remaining portion of the film (34), and wherein the conductive interconnection (54) comprises a conductive material (56) on the barrier layer (52, fig. 5, [0028]).
As to claim 7, Nag further teaches the seam has a seam depth defined as a vertical distance from a deepest point in the seam to the top surface of the metal plug; the remaining portion of the film has a vertical height from a lowest end to an uppermost end; and the vertical height is equal to the seam depth (fig. 5, the plug is grown inside the seam and fills it completely, thus the depths are equal).
As to claim 11, Nag teaches a method (Figs. 1-5) comprising: forming a metal structure (24) having a top surface (32) formed with a seam (30); sealing the seam with a cap (34); and forming a conductive interconnect (54) on the top surface of the metal structure (24, [0018], [0020]-[0023], and [0027]).
As to claim 12, Nag further teaches the metal structure is tungsten ([0018], “can also include one or more electrically conductive metals such as tungsten (W)”).
As to claim 13, Nag further teaches the cap (34) is an oxide, nitride, oxynitride, or metal layer ([0022]).
As to claim 14, Nag further teaches depositing an etch stop layer (38) on the over the metal structure (24) and cap (34, fig. 4, [0023]); forming a layer of dielectric material (40) over the etch stop layer (fig. 4, [0023]); etching the layer of dielectric material over the etch stop layer to form a trench (46, fig. 4, [0025]); removing the etch stop layer from over the metal structure to uncover the top surface of the metal structure (fig. 4, [0025], the etch stop layer is removed when forming the trench); and depositing a conductive material (56) in the trench to form a conductive interconnect in contact with the metal plug (fig. 5, [0027]), wherein forming the conductive interconnect (54) on the metal structure comprises depositing a conductive material in the trench ([0028]).
As to claim 15, Nag further teaches sealing the seam (30) with the cap (34) comprises: depositing a film (34) over the top surface of the metal structure (24) and at least partially filling the seam (fig. 3); and removing the film from over the metal structure to uncover at least a portion of the top surface of the metal structure, wherein the film remains in the seam (Fig. 3, [0022] – [0023]).
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.
Claim(s) 4 is rejected under 35 U.S.C. 103 as being unpatentable over Nag.
As to claim 4, Nag is silent on the thickness of the remaining portion of the film. However, it appears the Applicant does perform any special step that causes the thickness to be in the range claimed. Thus, it is a by-product of the steps performed, which are taught by Nag. Therefore, it is obvious, if not inherent, that the seam of Nag would also have a thickness of from 10 to 100 Angstrom.
Allowable Subject Matter
Claims 17-20 are allowed and claims 8-10 and 16 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: The prior art taken either singularly or in combination fails to anticipate or fairly suggest the limitations of the claims listed above in such a manner that a rejection under 35 U.S.C. 102 or 103 would be proper.
The prior art fails to teach a combination of all of the features in the claims. As to claim 8, the prior art fails to teach the seam has a seam depth defined as a vertical distance from a deepest point in the seam to the top surface of the metal plug; the remaining portion of the film has a vertical height less than the seam depth; and an air gap is enclosed within the seam and under the remaining portion of the film. There is no teaching or motivation for an air gap beneath the seam. In fact, Nag specifically grows the material of fill the seam so that there would NOT be an airgap.
As to claim 9, Nag further teaches forming the metal plug comprises forming the metal plug (24) in a dielectric layer (16, [0018], FIG. 2); depositing the film (34) over the top surface of the metal plug (24) and at least partially filling the seam comprises depositing the film over the dielectric layer (fig. 3).
Nag fails to teach after etching removing the film from over the metal plug, the film remains over the dielectric layer. Nag teaches completely etching the excess material away without leaving any on or over the dielectric layer.
Claim 10 depends from allowable claim 9.
As to claim 16, Nag further teaches forming the metal structure comprises forming the metal structure (24) in a dielectric layer (16, [0018], FIG. 2); and sealing the seam with the cap (34) comprises depositing a film over the dielectric layer, over the top surface of the metal structure, and at least partially filling the seam, and removing the film from over the metal structure (fig. 3).
Nag fails to teach the film remains in the seam and over the dielectric layer. Nag teaches completely etching the excess material away without leaving any on or over the dielectric layer.
As to claim 17, Nag teaches a metal interconnect (50, fig. 5) comprising: a metal structure (24) having a top surface (32) and a seam (30) extending from the top surface (32) into the metal structure (24), wherein the top surface of the metal structure terminates at a lateral sidewall (fig. 5); a liner (28) located on the lateral sidewall; a cap (34) located in the seam (30); and a conductive interconnect (54) located over the metal structure (24) and the cap (34).
Nag fails to teach the liner and the cap are formed from a same material. The “liner “ of Nag is a barrier layer formed on the inside sidewall of the via trench. The barrier layer and the cap are formed at different times for different purposes; thus it is not obvious that they would be formed of the same material.
Claims 18-20 depend on allowable claim 17.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
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 extension fee 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 date of this final action.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to KAREN M KUSUMAKAR whose telephone number is (571)270-3520. The examiner can normally be reached on Monday – Friday from 7:30a – 4:30p EST.
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/KAREN KUSUMAKAR/
Primary Examiner, Art Unit 2897
1/28/26