DETAILED ACTION
This office action is in response to the RCE filed 5/28/2026.
Currently, claims 1-6, 8-17 and 21-24 are pending.
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.
Claims 21, 23 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Hsueh et al. (US 2021/0287994) in view of Lanzillo et al. (US 2023/0144842).
Pertaining to claim 21, Hsueh shows, with reference to FIG. 7-15 and 3A, a method, comprising:
depositing a first dielectric layer (104a) over a substrate (102);
forming a first conductive feature (106) in the first dielectric layer;
depositing a first conductive capping layer (112) over the first conductive feature;
depositing an etch stop layer (105) over the first conductive capping layer;
depositing a second dielectric layer (104b) over the etch stop layer;
etching through the second dielectric layer and the etch stop layer to form an opening exposing a top surface of the first conductive capping layer (FIG. 9);
depositing an inhibitor film (1002) on the top surface of the first conductive capping layer;
depositing a barrier layer (118) on sidewalls of the opening;
after the depositing of the barrier layer, removing the inhibitor film (FIG. 12);
depositing a liner (122) on the barrier layer and the top surface of the first conductive capping layer (para. [0062] – [0063]);
depositing a seed layer (para. [0064]) on the liner; and
depositing a conductive filling layer (120) in the opening and over the seed layer.
Hsueh fails to show the step of depositing a second conductive capping layer over the conductive filling layer, wherein the top surface of the barrier layer and the top surface of the second conductive capping layer are coplanar, and wherein the second conductive capping layer interfaces with the barrier layer.
However, Lanzillo teaches in FIG. 2A that, for a similar interconnect structure, a conductive capping layer 224 is formed over the filling layer 220 such that the top surface of the barrier layer 212/230 and the top surface of the conductive capping layer are coplanar. As seen in FIG. 2A, the conductive capping 224 interfaces with the barrier layer 212/230.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hsueh to include a step of forming a conductive capping layer over the conductive filling layer, as taught by Lanzillo, with the motivation that the cap prevents electromigration of the conductive fill material into surrounding materials (para. [0036]).
Pertaining to claim 23, in the case that the step of depositing second barrier layer 310 is omitted as described in para. [0062], liner 122 would instead occupy the space occupied by barrier layer 310 in FIG. 13, including a portion that separates the barrier layer 118 from contacting the first conductive capping layer 112.
Pertaining to claim 24, Lanzillo teaches, prior to the depositing of the second conductive capping layer, recessing a top surface of the conductive filling layer below the top surface of the barrier layer (para. [0059], FIG. 5A).
Allowable Subject Matter
Claims 1-6 and 8-17 are allowed.
Claim 22 is 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 reasons for the indication of allowable subject matter are the same as discussed in previous office actions.
Response to Arguments
Applicant's arguments filed 5/28/2026 have been fully considered but they are not persuasive.
Applicant argues that Lanzillo does not teach the second conductive capping layer interfaces with the barrier layer, as a spacer, which is the purpose of Lanzillo’s invention, separates the second conductive capping layer interfaces with the barrier layer.
In response, because the material of the liner is a diffusion barrier material (para. [0052]), and because the spacer material may be the same material as that of the liner (para. [0063]), the combination of the liner and the spacer may be considered to be a diffusion barrier. Indeed, as taught by Lanzillo in para. [0063]), “depositing the spacer material results in the deposited spacer material becoming integrally formed with the existing liner material such that the spacer material and the liner material form one continuous body of homogenous material”. Thus, Lanzillo indeed teaches the second conductive capping layer interfaces with the barrier layer.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANIEL M LUKE whose telephone number is (571)270-1569. The examiner can normally be reached Monday-Friday, 9am-5pm, EST.
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/DANIEL LUKE/Primary Examiner, Art Unit 2896
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