DETAILED ACTION
This office action is in response to the RCE filed 8/27/2026.
Currently, claims 1-20 are pending. Claims 9-20 remain withdrawn from consideration.
Claim Objections
Claim 1 is objected to because of the following informalities: In lines 5-6, the limitation “inner sidewalls of the via and a trench” has been amended to “inner sidewalls of the via and on inner surfaces of a trench”. However, in lines 10 and 10-11, the original limitation remains.
Appropriate correction is required.
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.
Claims 1-8 are 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.
Claim 1 recites the limitation “forming a barrier layer selectively on inner sidewalls of the via and on inner surfaces of a trench”. It is not clear what is meant by the term “selectively” in view of the disclosure. “Selectively” is understood to mean preferential to one thing over another. Therefore, “selectively on inner sidewalls of the via and on inner surfaces of a trench” implies that the barrier layer is formed preferentially on the inner sidewalls of the via and on inner surfaces of the trench relative to other surfaces. However, as shown in FIG. 3C, the barrier layer 320 is formed in regions other than the inner sidewalls of the via and on inner surfaces of the trench, namely the top surface of the dielectric layer 312. In fact, FIG. 3C seems to show the barrier layer is actually thicker on the top surface of the dielectric layer compared with the inner sidewalls, implying that if there is any preference, it is to the top surface over the inner sidewalls. Thus, the meaning of the term “selectively” as recited in claim 1 is not clear.
Furthermore, claim 1 recites the limitation “selectively filling the via at least partially with a first conductive material”. Again, it is not clear what is meant by the term “selectively”. As seen in FIG. 3D-E, the first conductive material is grown on every surface. Indeed, the claim goes on to recite “growing the first conductive material from an exposed surface of the conductive layer at the bottom of the via and simultaneously on an exposed surface of the barrier layer on the inner sidewalls of the via and the trench. With the first conductive material being grown on all exposed surfaces, it is not clear what is meant by “selectively.
Finally, claim 1 recites the limitations “selectively filling the via at least partially with a first conductive material” and “filling a remaining portion of the via and the trench with a second conductive material”. The term “at least partially” allows for two scenarios – partially filling the via or entirely filling the via. In the case that the via is filled entirely with the first conductive material, there would be no space left to further fill the via with the second conductive material, as claimed.
Claims 2-8 recite the same limitations via dependency.
Claim Rejections - 35 USC § 102
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim 1-2 and 4-8 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Liu et al. (US 2022/0165616, cited in previous office action).
Pertaining to claim 1, Liu shows, with reference to FIG. 5-6, 15 and 18-21, a method of selectively filling a via with a simultaneous liner deposition in a semiconductor structure, comprising:
forming a passivation layer (601) selectively on a bottom of a via (2091 or 2111) formed in a dielectric layer (205/207) formed over a conductive layer (115);
forming a barrier layer (1501) selectively on inner sidewalls of the via and on inner surfaces of a trench (2092 or 2112) formed in the dielectric layer;
selectively filling the via at least partially with a first conductive material by growing the first conductive material from an exposed surface of the conductive layer at the bottom of the via and simultaneously on an exposed surface of the barrier layer on the inner sidewalls of the via and the trench (para. [0068]), to form a liner (1901) on the inner sidewalls of the via and the trench, wherein the first conductive material grows from the exposed surface of the conductive layer at a faster rate than that from the exposed surface of the barrier layer (FIG. 19 shows the rate of growth in the vertical direction is greater at the bottom than on the sides); and
filling a remaining portion of the via and the trench with a second conductive material (2003).
Pertaining to claim 2, Liu shows removing the passivation layer (FIG. 18), subsequent to the forming of the barrier layer (FIG. 15) and prior to the growing of the first conductive material (FIG. 19).
Pertaining to claim 4, Liu shows the passivation layer comprises a self-assembled monolayer (SAM) of organic molecules (para. [0046] – [0047]).
Pertaining to claim 5, Liu shows the dielectric layer comprises low k dielectric (SiOCH), silicon dioxide (SiO2), silicon nitride (Si3N4), silicon carbide (SiC), aluminum oxide (Al2O3), or aluminum nitride (AlN) (para. [0033], [0029]).
Pertaining to claim 6, Liu shows the barrier layer comprises tantalum nitride (TaN), metal doped TaN, titanium nitride (TiN), tungsten nitride (WN), or tungsten nitride carbide (WCN) (Liu, para. [0064]).
Pertaining to claim 7, Liu shows the first conductive material comprises copper (Cu), cobalt (Co), molybdenum (Mo), tungsten (W), or ruthenium (Ru) (Liu, para. [0068]).
Pertaining to claim 8, Liu shows the second conductive material comprises copper (Cu), cobalt (Co), ruthenium (Ru), or molybdenum (Mo) (Liu, para. [0069]).
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.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of Wu et al. (US 6,093,639, cited in previous office action).
Liu shows the method of claim 1, but fails to explicitly show the step of performing a liner treatment process to densify the liner, the liner treatment process comprising a plasma treatment or a gas soak.
However, Wu teaches in col. 2, lines 50-53 that, in a similar method for forming an interconnect structure, the liner layer is densified by a plasma process prior to depositing the metal fill.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to densify the liner layer of Liu using a plasma process, as taught by Wu, with the motivation that the densification process prevents the formation of voids in the subsequently formed metal fill (col. 2, lines 60-63).
Response to Arguments
Applicant's arguments filed 7/17/2026 have been fully considered but they are not persuasive.
With respect to the rejections under 35 U.S.C. 112, Applicant argues “As amended, claim 1 clearly indicates the barrier layer is formed on inner sidewalls of the via (314V) and on inner surfaces of a trench (314T), including the top surface of the dielectric layer 312, consistent with FIG. 3C. Thus, the claim expressly identifies the surface relative to which the selective formation occurs and clarifies the meaning of the term ‘selectively.’”
This is merely an assertion, with which the Examiner disagrees. Particularly, it is not clear how the top surface of the dielectric layer is considered to be an inner surface of the trench, as Applicant argues. There is no claim language about the top surface of the dielectric layer. It is still unclear how the deposition could be considered to be selective to the inner sidewalls of the via and the inner surfaces of the trench, when deposition also occurs on the top surface of the dielectric.
With respect to the prior art rejections, Applicant argues that Liu does not disclose “selectively filling the via at least partially with the first conductive material” because Liu describes the first conductive material as a thin adhesion layer and not as a material that selectively fills the via from the bottom while simultaneously forming the liner.
In response, the claim does not require a certain thickness to be associated with the term “filling”. Even for a relatively thin layer, its presence redefines the space that is empty within the via to a smaller space. Thus, Liu indeed discloses the partial filling of the via with the first conductive material. Even so, Liu shows the first conductive material to be thicker at the bottom of the via relative to the sidewalls (FIG. 19), just as in Applicant’s FIG. 3E.
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
