DETAILED ACTION
This office action is in response to the amendment filed 2/3/2026.
Currently, claims 1-16 and 18-20 are pending. Claims 2, 5, 7-8, 10, 15, 18 and 20 remain withdrawn from consideration. Claim 17 has been canceled.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1, 3-4, 6, 9, 11-14, 16 and 19 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Independent claims 1 and 19 have been amended to recite the limitation “depositing a first ruthenium layer directly on the underlying copper interconnect layer”, while independent claim 11 has been similarly amended to recite “depositing, directly on the conductive material of the underlying interconnect layer, the second metal layer”. Such a feature is not disclosed in the originally filed application, particularly in combination with the limitation that the first ruthenium layer has a thickness of 5 angstroms or less (claims 1 and 19), or that the second metal layer has a thickness that is 5% to 30% of the thickness of the first metal layer, which is itself 30 angstroms.
While FIG. 1 shows an Ru layer 104 as the first layer above substrate 102, there is explicitly not an underlying copper layer on which the Ru is formed. From para. [0025]:
The first interconnect layer, MO 104, can be formed using a thick ruthenium containing liner layer because no underlying copper is present on the substrate 102. However, subsequent interconnect layers such as MX1 106, MX2 108, and MXN 110 cannot be formed with a ruthenium liner layer due to migration issues of the underlying copper in the previously formed interconnect layer.
FIG. 2 has no Ru layer. Again from para. [0025]:
As depicted in a view 200 of Fig. 2, cobalt is then used as the liner layer material to produce a cobalt liner layer 216 on an opening 214 of an MX layer 210. The cobalt liner layer 216 traditionally has a thickness 220 of 30 angstroms to 35 angstroms.
FIG. 3 uses a Ru layer, but it is thick and causes issues. Also, there is no Co layer. From para. [0026]:
As depicted in a view 300 of Fig. 3, the inventors also found that the use of a thick ruthenium liner layer 330 on the MX layer 210 causes copper migration 336 issues from an underlying copper interconnect 340. The copper material migrates from the underlying copper interconnect 340 through the thick ruthenium liner layer 330 and into the opening 214 forming copper material 332 in the opening. The migrating copper from the underlying copper interconnect 340 leaves a void 334 in the underlying copper interconnect 340, reducing the performance of the underlying copper interconnect 340.
FIG. 4 shows both Co and Ru, but it is the Co layer that is directly on the underlying copper, not Ru.
Moving to FIG. 5, the only embodiment that shows the underlying copper is 500A. However, it is Co and not Ru that is deposited directly on the copper/interconnect. From para. [0029]:
The inventors have found that deposition of the first metal liner layer 402, for example cobalt, on the underlying conductive interconnect 506 allows the cobalt material of the first metal liner layer 402 to form a better first interfacial layer 504 with the underlying conductive interconnect 506.
500B and 500D are the only embodiments shown in FIG. 5 for which the bottom layer is the Ru layer. However, there is no mention anywhere in the disclosure that the Ru layer is directly deposited on the underlying copper/interconnect layer. On the contrary, the disclosure suggests that the Ru layer would instead be deposited on a barrier layer, and thus would be prevented from being deposited directly on the underlying copper/interconnect layer by the barrier layer. See FIG. 7, particularly step 706. Also, from para. [0032]:
In block 702, a barrier layer is deposited on a subsequently formed interconnect layer … In some embodiments, deposition methods of the metal liner layer of block 706 may include some embodiments (706A, 706B, 706C) as depicted in views 800A, 800B, 800C, and 800D of Fig. 8. In block 802A, a ruthenium layer is deposited with a thickness of approximately 5 angstroms or less (see, e.g., view 500B of Fig. 5). In block 804A, a cobalt layer of approximately 20 angstroms or less is deposited on the ruthenium layer (see, e.g., view 500B of Fig. 5).
Lastly, even if the limitation regarding the deposition of the Ru layer directly on the copper/interconnect layer were supported by the original disclosure, then the claims would be directed towards an invention other than the elected invention. The elected invention is the method depicted in FIG. 7, where step 706 is step 706A from FIG. 8. The method depicted in FIG. 7 includes step 702 in which the barrier layer is deposited, and step 706 in which the metal liner is deposited on the barrier layer (and thus would not be deposited directly on the copper/interconnect layer).
Response to Arguments
Applicant’s arguments have been considered and are persuasive. However, the amendments to the claims introduce new issues that lead to rejection under 35 U.S.C. 112(a) as discussed in the rejections above.
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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, William Kraig can be reached at (571) 272-8660. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/DANIEL LUKE/Primary Examiner, Art Unit 2896
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