DETAILED ACTION
Table of Contents
I. Notice of Pre-AIA or AIA Status 3
II. Claim Objections 3
III. Claim Rejections - 35 USC § 112 3
A. Claims 1-14 and 19 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. 3
1. Claim 1 3
2. Claim 8 4
3. Claim 3 4
4. Claim 19 4
IV. Claim Rejections - 35 USC § 103 4
A. Claims 1, 2, 5-7, 9, and 11-19 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0351072 (“Chen”). 5
B. Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US 2017/0241019 (“Sowa”). 10
C. Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US 6,743,473 (“Parkhe”). 11
D. Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US 2010/0221577 (“Dussarrat”). 12
V. Pertinent Prior Art 13
Conclusion 13
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I. 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 .
II. Claim Objections
Claim 19 objected to because of the following informalities:
In the last line of claim 19, replace “ntiride” with “nitride” for correct spelling.
Appropriate correction is required.
III. 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.
A. Claims 1-14 and 19 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
1. Claim 1
The last two lines of claim 1 recite the limitation “a ruthenium doped niobium nitride barrier layer”. The antecedent basis is unclear because the same limitation is recited in the claim preamble.
Claims 2-14 are rejected for including the same indefinite feature by depending from claim 1 either directly or indirectly.
2. Claim 8
Claim 8 reads,
8. The method of claim 1, wherein the first NbN barrier film and the second NbN barrier film comprise Nb3N4.
Claim 8 is unclear because it is unclear because it may be read in more that one way. In this regard, the chemical formula NbN has a stoichiometric ratio of Nb:N of 1:1, while Nb3N4 has a stoichiometric ratio of Nb:N of 3:4. As such, the claim may be interpreted as requiring both NbN and Nb3N4 to be present in the niobium nitride barrier films or just Nb3N4.
3. Claim 3
Claim 12 recites the limitation “the doped barrier layer”. There is insufficient antecedent basis for this limitation in the claim. As such, it is unclear if the antecedence is to one of the first and second barrier films or to the “ruthenium doped niobium nitride barrier layer” recited in claim 1.
4. Claim 19
Claim 19 recites each of the limitations, “the first metal nitride film” and “the second metal nitride [sic] film”. There is insufficient antecedent basis for these limitations in the claim.
IV. 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 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 of this title, 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.
A. Claims 1, 2, 5-7, 9, and 11-19 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0351072 (“Chen”).
The applied reference has a common Assignee with the Instant Application. Based upon the earlier effectively filed date of the reference, it constitutes prior art under 35 U.S.C. 102(a)(2). This rejection under 35 U.S.C. 102(a)(2) might be overcome by: (1) a showing under 37 CFR 1.130(a) that the subject matter disclosed in the reference was obtained directly or indirectly from the inventor or a joint inventor of this application and is thus not prior art in accordance with 35 U.S.C. 102(b)(2)(A); (2) a showing under 37 CFR 1.130(b) of a prior public disclosure under 35 U.S.C. 102(b)(2)(B) if the same invention is not being claimed; or (3) a statement pursuant to 35 U.S.C. 102(b)(2)(C) establishing that, not later than the effective filing date of the claimed invention, the subject matter disclosed in the reference and the claimed invention were either owned by the same person or subject to an obligation of assignment to the same person or subject to a joint research agreement.
In addition to including any one of the statements pursuant to 35 U.S.C. 102(b)(2)(A) through (C), (supra), to overcome Chen as prior art available under 35 USC 102(a)(2), it is still applicable as prior art under 35 U.S.C. 102(a)(1) that cannot be excepted under 35 U.S.C. 102(b)(2)(C). In this instance, Applicant may rely on the exception under 35 U.S.C. 102(b)(1)(A) to overcome this rejection under 35 U.S.C. 102(a)(1) by a showing under 37 CFR 1.130(a) that the subject matter disclosed in the reference was obtained directly or indirectly from the inventor or a joint inventor of this application, and is therefore not prior art under 35 U.S.C. 102(a)(1). Alternatively, applicant may rely on the exception under 35 U.S.C. 102(b)(1)(B) by providing evidence of a prior public disclosure via an affidavit or declaration under 37 CFR 1.130(b).
Turning now to the rejection …
With regard to claim 1, Chen discloses,
1. A method for forming a ruthenium doped niobium nitride barrier layer, the method comprising:
[1] forming a first niobium nitride (NbN) barrier film 214 on a substrate 102(202) by a first ALD process [¶¶ 40-46; step 104 in Fig. 1; Fig. 3A];
[2] doping the first barrier film 214 with ruthenium by a flash chemical vapor deposition process [¶¶ 5, 6, 47, and Examples 1 through 6 on p. 8, ¶¶ 87-92; step 106 in Fig. 1; Fig. 3B]; and
[3] forming a second niobium nitride barrier film 218 on the doped first barrier film by a second ALD process to form a ruthenium doped niobium nitride barrier layer [¶¶ 55-56 and Examples 1 through 6 on p. 8, ¶¶ 87-92; step 108 in Fig. 1; Fig. 3C].
Chen provides six examples of forming a Ru doped TaN barrier layer by repeating cycles of a first phase of ALD deposition of TaN followed a second phase of Ru doping of the TaN by flash CVD, followed by a final ALD layer of TaN (Examples 1 and 2) or then repeating both phases at least one more time, and finishing with a final ALD layer of TaN (Examples 3-6).
Chen does not provide a specific example of making the metal nitride from niobium. However, Chen explicitly states that each of the first 214 and second 218 metal nitrides deposited by ALD that is doped with, e.g. Ru, may be niobium nitride (¶¶ 45-46, 55-56).
In addition, Chen indicates that the metal dopant deposited by flash CVD may be Ru (¶ 47) and provides six examples wherein flash CVD doping with specifically Ru, albeit with the example metal nitride of TaN (p. 8, ¶¶ 87-92).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to make each of the first, second, and subsequent metal nitride films from ALD NbN, each doped with Ru by flash CVD except for the final NbN film because Chen explicitly suggests using each of NbN as the barrier metal nitride and Ru dopant.
This is all of the features of claim 1.
Claim 2 reads,
2. The method of claim 1, wherein the first ALD process and the second ALD process are performed with the same reactants and the same processing conditions.
Chen states that each of the first 214 and second 218 films making the doped metal nitride barrier layer is the “same material” (¶ 55) and uses the same conditions for each of the TaN films in the six examples on page 8, i.e. the same Ta precursor as the Ta source and same ammonia reactant as the N source at the same temperature range of 250 ℃ to 275 ℃.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use the same conditions to deposit each of the ALD films of NbN because Chen teaches, by the six examples on page 8, that each of the ALD metal nitride layers can be deposited using the same conditions. Moreover, one having ordinary skill in the art would recognize that using the same conditions would simplify the deposition process.
With regard to claims 5-7, Chen further discloses,
5. The method of claim 2, wherein the ALD process comprises ammonia [¶¶ 6, 30, Examples 1 through 6 on p. 8, ¶¶ 87-92].
6. The method of claim 2, wherein the ALD process comprises a plasma reactant [¶¶ 26, 31].
7. The method of claim 2, wherein the ALD process is performed at a temperature less than or equal to 300 ℃ [Examples 1-6 on p. 8, ¶¶ 87-92].
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use each of ammonia, PEALD, and a temperature in the range of 250 ℃ to 275 ℃ to deposit the NbN film because Chen teaches that these conditions are suitable for depositing a metal nitride film.
With regard to claim 9, Chen further discloses,
9. The method of claim 1, wherein the flash chemical vapor deposition process comprises a ruthenium precursor and hydrogen gas (H2) [¶ 33, ].
Chen states,
[0033] Depending on the dopant precursor used, a co-reactant may be used to deposit the dopant. For example, reducing gases such as hydrogen and ammonia can be used as co-reactants for depositing some dopants. Metal dopant precursors and co-reactants may be either co-flowed or flowed sequentially.
(Chen: ¶ 33; emphasis added)
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to co-flow hydrogen gas along with the Ru precursor in the flash CVD of the Ru dopant because Chen suggests including hydrogen.
With regard to claims 11-14, Chen further discloses,
11. The method of claim 1, wherein the ruthenium dopant forms an intermetallic composite with the first barrier film and the second barrier film [¶ 50].
12. The method of claim 1, wherein the doped barrier layer has a thickness less than about 15 Å [abstract, ¶¶ 57, Examples 1 through 6 on p. 8, ¶¶ 87-92].
13. The method of claim 1, further comprising exposing the doped barrier layer to one or more of plasma treatment, physical vapor deposition (PVD) treatment, thermal anneal, or chemical enhancement after doping [step 110 in Fig. 1; ¶¶ 37, 60, and Examples 5 and 6 on p. 8, ¶¶ 91-92].
14. The method of claim 1, wherein the substrate 202(102) comprises at least one feature 206 [¶ 40; Figs. 2, 3A-3C].
Claim 15 reads,
15. A method of forming a ruthenium doped niobium nitride layer, the method comprising:
[1a] exposing a substrate to a niobium precursor and ammonia to form a first barrier film on the substrate,
[1b] the substrate comprising a dielectric layer having at least one feature;
[2] doping the first barrier film with ruthenium by exposing the first barrier film to a ruthenium precursor and hydrogen gas (H2) in a flash chemical vapor deposition process; and
[3] exposing the substrate to the niobium precursor and ammonia to form a second barrier film on the doped first barrier film; and
[4] repeating the flash chemical vapor deposition process or the flash chemical vapor deposition process and formation of the second barrier film to form a doped metal nitride layer.
Each of the limitations of claim 15 has been addressed above under claims 1, 5, 9, and 14, the repeating step(s) of feature [4] of claim 15 discussed in conjunction with Examples 4, 5, and 6 of Chen at page 8.
Claims 16 and 17 read,
16. The method of claim 15, wherein the doped metal nitride layer has a thickness of less than about 15 Å.
17. The method of claim 15, further comprising exposing the doped metal nitride layer to one or more of plasma treatment, physical vapor deposition (PVD) treatment, thermal anneal, or chemical enhancement.
See discussion under claims 12 and 13.
With regard to claim 18, Chen further discloses
18. The method of claim 15, wherein the first metal nitride film 214 is substantially conformal over the at least one feature 206 [as shown in Fig. 3A which is identical to Fig. 3A of the Instant Application].
With regard to claim 19, Chen further discloses,
19. The method of claim 15, wherein the dopant metal diffuses through the first metal nitride film to the dielectric film (¶ 49), or wherein the dopant metal forms an intermetallic compound with the first metal nitride film and the second metal ntiride film.
B. Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US 2017/0241019 (“Sowa”).
Claims 3 and 4 read,
3. The method of claim 2, wherein the ALD process comprises a niobium precursor substantially free of halide.
4. The method of claim 3, wherein the niobium precursor comprises tris(diethylamido)(tert-butylimido)niobium.
The prior art of Chen, as explained above, teaches each of the features of claims 1 and 2.
Chen does not provide any specific Nb precursors for the ALD process.
Sowa, like Chen, teaches ALD and PEALD of metal-based films (Sowa: ¶ 2), which may be Nb-based films (Sowa: ¶¶ 14, 53), including specifically NbN (Sowa: ¶ 62). Sowa further discloses, using tris(diethylamido)(tert-butylimido)niobium as the Nb precursor (Sowa: ¶ 53), which is halide free.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use tris(diethylamido)(tert-butylimido)niobium as the Nb source in the ALD or PEALD deposition of the NbN film of Chen because Chen is merely silent as to the Nb precursor, such that one having ordinary skill in the art would use known Nb precursors suitable for the same purpose of ALD and PEALD of NbN films, such as the Nb precursor, tris(diethylamido)(tert-butylimido)niobium, taught in Sowa for this specific purpose.
As such, the selection of tris(diethylamido)(tert-butylimido)niobium amounts to obvious material choice. (See MPEP 2144.07.)
This is all of the limitations of claims 3 and 4.
C. Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US 6,743,473 (“Parkhe”).
Claim 8 reads,
8. The method of claim 1, wherein the first NbN barrier film and the second NbN barrier film comprise
The prior art of Chen, as explained above, teaches each of the features of claim 1.
Chen does not teach the stoichiometry Nb3N4 used as the niobium nitride film.
Parkhe, which shares as common assignee with each of Chen and the Instant Application, teaches a barrier layer 119 in a trench (Parkhe: Fig. 1; col. 8, lines 51-65), which may be a metal nitride (Parkhe: paragraph bridging cols. 3-4; , lines col. 7, line 65 to col. 8, line 24), e.g. niobium nitride (paragraph bridging cols. 1-2; col. 22, lines 14-37). Parkhe further teaches that the niobium nitride can have the Nb3N4 stoichiometry (col. 22, lines 14-16).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to make the first 214 and second 218 niobium nitride barrier films to have the Nb3N4 stoichiometry because Parkhe teaches that this stoichiometry is suitable for the same purpose as that for which the niobium nitride layer is used in Chen, i.e. diffusion barrier layer in a metallization structure.
This is all of the limitations of claim 8.
D. Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of US 2010/0221577 (“Dussarrat”).
Claim 10 reads,
10. The method of claim 9, wherein the ruthenium precursor comprises methylcyclohexadiene ruthenium tricarbonyl.
The prior art of Chen, as explained above, teaches each of the features of claims 1 and 9.
Chen teaches that the precursors for the metal dopants include “organic or carbonyl” ligands but does not give any examples of any metal precursor, not even the Ru precursor used in the six examples on page 8.
Dussarrat teaches methylcyclohexadiene ruthenium tricarbonyl as a CVD precursor along with H2 as a co-reactant for deposition of Ru films (Dussarrat: Fig. 2; ¶¶ 27, 39, 41, 47, 50, 58).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use methylcyclohexadiene ruthenium tricarbonyl as the precursor in the flash CVD of the Ru dopant because Dussarrat teaches that it is an old and well-known Ru precursor suitable for forming CVD Ru film, along with hydrogen, as used in the Instant Application and in Chen. As such the selection of methylcyclohexadiene ruthenium tricarbonyl amounts to obvious material choice. (See MPEP 2144.07.)
V. Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Thiede, Tobias B., et al., “Deposition of Niobium Nitride Thin Films from Tert-Butylamido-Tris-(Diethylamido)-Niobium by a Modified Industrial MOCVD Reactor” Chemical Vapor Deposition 2009, 15, pp. 334-341 is cited for teaching a halide-free organometallic Nb precursor along with ammonia co-reactant for depositing NbN films.
US 2008/0152793 (“Gatineau”) is cited for teaching a CVD deposition process usings a co-flow of hydrogen (¶¶ 35, 36, 39).
Conclusion
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Signed,
/ERIK KIELIN/
Primary Examiner, Art Unit 2814