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 .
Claim Objections
Claim 28 is objected to because of the following informalities: There is a minor grammatical error in Claim 28; “the” appears to be omitted between “wherein” and “nitrogen”. Appropriate correction is required.
In the interest of compact prosecution, Claim 28 is being examined as requiring the nitrogen-containing reactant of Claim 25.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 21-26 and 28-31 are rejected under 35 U.S.C. 103 as being unpatentable over Shrestha ‘014 (U.S. PGPub 2019/0067014) in view of Zierath ‘949 (U.S. PGPub 2015/0371949).
Claim 21 – Shrestha ‘014 teaches a method (e.g. PG 0088-0096, Fig 4A and 4B) comprising:
(a) providing a substrate having a plurality of features spaced apart, each feature having a feature opening width (PG 0089, exemplifying a singular feature; PG 0088 expressly contemplates substrates with multiple features commensurate with the claim; the feature comprises an aspect ratio which necessitates the presence of a feature height and a feature opening width) with a metal nitride layer in the features (PG 0090, metal nitride present in the features prior to deposition); and
(b) depositing a bulk molybdenum layer in the feature (PG 0090). Examiner notes that disclosed methods of formation comprise e.g. ALD (PG 0059-0060).
Shrestha ‘014 does not expressly teach or suggest the following limitations of Claim 21:
depositing a conformal molybdenum nitride liner layer in the features; and
after depositing the conformal molybdenum nitride liner layer in the features, depositing a bulk molybdenum layer in the feature.
Zierath ‘949 is drawn to the formation of metal-filled semiconductor substrate features via e.g. ALD processes (Abstract, PG 0019, 0027, 0028) and discloses a process where layered materials are deposited into a semiconductor substrate feature followed by bulk deposition of a fill material (PG 0026-0032 broadly; PG 0032 discloses the deposition of an ESM material followed by an EFM material. The ESM material is discussed at PG 0028 and defined at PG 0010; the ESM may be chosen to be e.g. molybdenum nitride at PG 0028. The EFM material is discussed at PG 0030 and defined at PG 0010; the EFM material may be chosen to be metal at PG 0030. Therefore, it would have been obvious to a person having ordinary skill in the art at the time the invention was made or filed to have modified the invention of Shrestha ‘014 to deposit molybdenum nitride in its semiconductor features as suggested by Zierath ‘949 prior to bulk filling with molybdenum, as Shrestha ‘014 discloses the desirability of depositing bulk molybdenum in semiconductor features over metal nitride liner layers and Zierath ‘949 discloses that molybdenum nitride is a known barrier liner layer used in the process of filling semiconductor features with bulk metals. As discussed above, both methods contemplate operations with ALD processes.
Claim 22 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 21, wherein the conformal molybdenum nitride liner layer has a thickness between 10 and 40 Angstroms (Zierath ‘949 discloses an ESM layer thickness of one monolayer to several hundred nanometers at PG 0028; this corresponds to fractions of an Angstrom to several thousand Angstroms. Selection of a value commensurate with the claims from within the encompassing range disclosed by Zierath ‘949 is held as prima facie obvious).
Claim 23 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 21, further comprising after (c), (d) depositing molybdenum in the feature having a higher impurity level than the molybdenum deposited in (c) (Zierath ‘949 renders obvious partial filling of a gap at PG 0030 and discloses an express embodiment at PG 0046-0052 which renders obvious partial gap fill of an EFM, deposition and etching of ESM, and deposition of cap material [specifically PG 0051 and Figure 0051]. In the combined structure of Shrestha ‘014 / Zierath ‘949, this renders obvious further deposition of molybdenum nitride after deposition of bulk molybdenum given the previous choices of those materials as ESM and EFM materials in the rejection of Claim 21. Since bulk molybdenum does not contain nitrogen, the further deposited molybdenum nitride has a higher impurity of nitrogen than the bulk molybdenum.).
Claim 24 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 23, wherein the impurity deposited in (d) reduces interatomic forces between molybdenum atoms on opposing sidewalls of a feature (molybdenum nitride is a semiconductor; a film of molybdenum nitride connecting both sides of a substrate feature as discussed in the rejection of Claim 23 reduces electrical resistance between the sidewalls compared to the alternative of an air gap between them).
Claim 25 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 23, wherein the molybdenum nitride liner in (b) is deposited by reacting a molybdenum-containing precursor with a nitrogen-containing reactant (Shrestha ‘014 PG 0061 for molybdenum containing precursors; Shrestha ‘014 PG 0065 for nitrogen containing precursors).
Claim 26 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 25, wherein the molybdenum-containing precursor is a molybdenum halide or molybdenum oxyhalide (Shrestha ‘014 PG 0061).
Claim 28 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 25, wherein nitrogen-containing reactant is ammonia (Shrestha ‘014 PG 0065).
Claim 29 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 21, wherein the plurality of features are horizontally-oriented (Shrestha ‘014 PG 0094, a substrate with one or more horizontal high aspect ratio gap features).
Claim 30 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 21, wherein the plurality of features are vertically-oriented (Shrestha ‘014 PG 0088 and 0089, a substrate with one or more vertical high aspect ratio gap features).
Claim 31 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 23, wherein the impurity is nitrogen (Shrestha ‘014 PG 0090, metal nitride generally; Zierath ‘949 PG 0028, molybdenum nitride specifically).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Shrestha ‘014 / Zierath ‘949 as applied to claim 25 above, and further in view of Zhu ‘573 (U.S. PGPub 2019/0027573).
Claim 27 – Shrestha ‘014 / Zierath ‘949 render obvious the method of claim 25, but do not expressly teach or suggest wherein the molybdenum-containing precursor is an organometallic precursor. Zhu ‘573 discloses precursor chemistries for ALD of molybdenum nitride (PG 0020-0029 broadly) and discloses that molybdenum halides and organomolybdenum precursors are both suitable as ALD molybdenum sources (PG 0023 specifically). Therefore, it would have been obvious to a person having ordinary skill in the art at the time the invention was made or filed to have modified the invention of Shrestha ‘014 / Zierath ‘949 to use an organomolybdenum precursor, e.g. tetrachloro(cyclopentadienyl)molybdenum, as the ALD molybdenum source as suggested by Zhu ‘573, as Shrestha ‘014 discloses molybdenum halides as known ALD molybdenum sources and Zhu ‘573 discloses organomolybdenum precursors as suitable alternative ALD molybdenum sources to molybdenum halides. Selection of a material disclosed in the prior art as suitable for the inventive purpose is held as prima facie obvious.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL G MILLER whose telephone number is (571)270-1861. The examiner can normally be reached M-F 9:00-5:30 EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Michael Cleveland can be reached at 571-272-1418. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/MICHAEL G MILLER/ Primary Examiner, Art Unit 1712