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 Rejections - 35 USC § 102
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 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(s) 1-3, 5, and 6 is/are rejected under 35 U.S.C. 102(a)(1) as being unpatentable by Li et al. (US 20200350159).
Regarding claim 1, Li et al. taches a method of forming a film of a low-resistance material on a semiconductor su3bstrate using physical vapor deposition (PVD) [¶0006], the method comprising:
Step (a) of depositing a barrier layer on a SiO2 wafer using low-temperature [¶0062, low temperature in chamber in range 16-25°C] magnetron sputtering at a pressure of 1 to 40 pascal (Pa) [¶0033, pressure from about 1 mTorr to 150 mTorr which is about 0.1 to 20 Pa];
Step (b) of modifying, after the barrier layer is deposited, the surface of the barrier layer by applying a radio frequency (RF) bias in an argon (Ar) gas atmosphere without applying direct current (DC) power [¶¶0023 and 0034, Rf and/or DC in some embodiments, so there could be embodiments with only RF, argon used as inert gas to facilitate sputtering]; and
Step (c) of depositing a low-resistance material on the barrier layer using magnetron sputtering [¶0019],
Wherein the low-resistance material is at least one selected from the group consisting of tungsten (W), ruthenium (Ru), molybdenum (Mo), cobalt (Co), and rhodium (Rh) [¶0018, cobalt].
Regarding claim 2, Li et al. teaches the method of claim 1, wherein the barrier layer is at least on selected from the group consisting of titanium nitride (TiN), tantalum nitride (TaN), and silicon nitride (SiNx, where x>0) [¶0026, TiN and TaN].
Regarding claim 3, Li et al. teaches the method of claim 1, wherein the thickness of the barrier layer is 4 nanometers (nm) or less [¶0026, 10-50A which is 1-5 nm].
Regarding claim 5, Li et al. teaches the method of claim 1, wherein step (b) comprises:
Applying the RF bias of 100 to 300 W for 10 to 60 seconds [¶0021, RF bias power between 0.25-6kW].
Regarding claim 6, Li et al. teaches the method of claim 1, wherein step (b) comprises:
Applying the RF bias of 300 W for 10 seconds [¶0021, within the range of 0.25-6 kW].
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.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 20200350159) in further view of Klawuhn et al. (US 7510634 B1) and Berg & Nyberg (“Fundamental understanding and modeling of reactive sputtering processes,” Thin Solid Films 476 (2005) 215–230) hereafter "Berg" .
Regarding claim 4, Li et al. teaches the method of claim 1, wherein the barrier layer is a TiN layer.
Li et al. doesn’t teach the operating conditions for performing the magnetron sputtering.
Klawuhn et al. teaches the method for deposition in a semiconductor wafer that has operating conditions for performing the magnetron sputtering step (a) comprise DC of 10 kilowatts (kW) to 30 kW, RF of 200 watts (W) or less [Col. 5, Lines 18-35, DC 10-70kW and RF bias 0 to 1200W], and pressure of 1 to 40 Pa [Col. 6, Lines 51-57, pressure conditions optimized based on other conditions as stated in art].
It would have been obvious for a person with ordinary skill in the art before the effective filing date to combine the deposition methods of Li et al. with the deposition methods of Klawuhn et al. to the obtain the claimed conditions for performing magnetron sputtering because through routine experimentation, the desired operating conditions for performing the magnetron sputtering can be found.
In addition, the selection of operating conditions, it's obvious because it is a matter of determining optimum process conditions by routine experimentation with a limited number of species of result effective variables. These claims are prima facie obvious without showing that the claimed ranges achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996)(claimed ranges or a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill or art) and In re Aller, 105 USPQ 233 (CCPA 1995) (selection of optimum ranges within prior art general conditions is obvious).
Note that the specification contains no disclosure of either the critical nature of the operating conditions or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen operating conditions or upon another variable recited in a claim, the Applicant must show that the chosen operating conditions is critical. In re Woodruf, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Li et al. in view of Klawuhn et al. doesn’t teach the operating condition of Ar/N2 ratio of 1/10 or less.
However, Berg provides the additional teaching needed for the Ar/N₂ ≤ 1/10 limitation. Berg explain that to achieve stoichiometric TiN films in reactive sputtering, it is conventional to operate in a nitrogen-rich regime, i.e., at high N₂ partial pressure relative to Ar. See, e.g., pages 216–217 (Introduction and Figs. 1–2), and page 220, Fig. 6, which show that increasing the supply or partial pressure of N₂ results in target poisoning and deposition of stoichiometric nitride films. The review further states that the reactive gas fraction is the main control knob for moving between metallic, transition, and poisoned (fully-nitrided) modes, and that operating at high N₂ partial pressure (i.e., Ar/N₂ flow ratio well below unity) is conventional and necessary to achieve fully reacted (stoichiometric) TiN. Therefore, one of ordinary skill in the art would have been motivated to select an Ar/N₂ ratio of 1/10 or less as a routine parameter for obtaining stoichiometric TiN films by reactive sputtering, as taught by Berg.
Accordingly, it would have been obvious to combine the TiN barrier layer and magnetron sputtering process of Li et al. and Klawuhn et al. with the high N₂ fraction reactive sputtering regime taught by Berg & Nyberg, thereby arriving at the claimed method with an Ar/N₂ ratio of 1/10 or less, with predictable results.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being obvious over Li et al. (US 20200350159).
Regarding claim 7, Li et al. teaches the method of claim 1, wherein a deposited thickness in step (c) is 10 nm [¶0030, Cobalt is 10-100 A which is 0.1-10nm].
Li et al. doesn’t teach the method of claim 1, wherein the deposited thickness in step (c) is 10 to 30 nm.
It would have been obvious to a person with ordinary skill in the art before the effective filing date to implement the claimed range of deposited thickness in the methods found through routine experimentation to achieve the optimal adhesion.
In addition, the selection of low-resistance material thickness, it's obvious because it is a matter of determining optimum process conditions by routine experimentation with a limited number of species of result effective variables. These claims are prima facie obvious without showing that the claimed ranges achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996)(claimed ranges or a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill or art) and In re Aller, 105 USPQ 233 (CCPA 1995) (selection of optimum ranges within prior art general conditions is obvious).
Note that the specification contains no disclosure of either the critical nature of the claimed low-resistance material thickness or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen low-resistance material layer thickness or upon another variable recited in a claim, the Applicant must show that the chosen low-resistance material layer thickness is critical. In re Woodruf, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Claim(s) 8, 9, 11, and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 20200350159) in further view of Shaviv et al. (US 8298933 B2).
Regarding claim 8, Li et al. teaches the method of claim 1.
Li et al. doesn’t teach what step (c) comprises.
Shaviv et al. teaches the deposition method of step (c) comprises:
Forming a nucleation layer (seed layer) of the low-resistance material [Col. 3, Lines 1-16]; and
Forming a crystal layer of the low-resistance material [Col. 3, Lines 1-16, crystal layer is a broad term that can be encompassed by seed layer especially in the context which it is in and the same material is used for both, as written in claims and spec, and is within reason as adding a crystal layer could decrease warping as is known in the art].
It would have been obvious to a person with ordinary skill in the art before the effective filing date of the claimed methods to combine the deposition methods of Li et al. with the deposition methods of Shaviv et al. because the formation of the nucleation and crystal layers would help with the stability of the semiconductor.
Regarding claim 9, Li et al. in further view of Shaviv et al. teaches the method of claim 8, wherein the thickness of the nucleation layer (seed layer) is 4nm or more [Col. 3 Lines 1-16, first deposited amount between 20-100 Angstroms, Shaviv et al.].
Regarding claim 11, Li et al. in further view of Shaviv et al. teaches the method of claim 8, wherein RF in the forming of the nucleation layer is 0 W [¶0023, states RF energy or DC energy and it is reasonable to interpret that forming the nucleation layer can be done through just DC energy, Li et al.].
Regarding claim 12, Li et al. in further view of Shaviv et al. teaches the method of claim 9, wherein a sum of the thickness of the nucleation layer (seed layer) and the thickness of the crystal layer is 10 to 30 nm [Col. 3 Lines 1-16, first deposition from 20 to 100 Angstroms and second deposition from 5 to 50 Angstroms, total can be found in claimed range].
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 20200350159) in further view of Shaviv et al. (US 8298933 B2) and Klawuhn et al. (US 7510634 B1).
Regarding claim 10, Li et al. in view of Shaviv et al. teaches the method of claim 8.
Li et al. in view of Shaviv et al. doesn’t teach the formation of the crystal layer having a higher DC power applied than during nucleation.
Klawuhn et al. teaches the deposition method where the forming of the crystal layer (multiple layers of seed layer with same material used) comprises: applying DC power higher than that used for the forming of the nucleation layer [Col. 5, Lines 18-35, the deposition at target would have a DC range from 10-70kW so it would be reasonable to have the seed/nucleation layer created at a lower DC power and the crystal layer created at a higher DC power].
It would have been obvious to a person of ordinary skill in the art to implement the Shaviv et al. two-stage seed/growth sequence in Li et al.’s PVD flow while selecting a lower DC target power during the seed (nucleation) step to promote uniform wetting/continuity and a higher DC target power during the subsequent crystal (bulk growth) step to increase deposition rate and promote the desired crystalline microstructure—i.e., to form the crystal layer at a higher DC than the nucleation layer—as a routine optimization of a result-effective variable within the DC power ranges taught by Klawuhn et al. Such stepwise power adjustment in sequential PVD steps is a predictable modification to achieve known outcomes in nucleation versus bulk growth and falls within ordinary skill in the art. See, e.g., In re Woodruff, 919 F.2d 1575, 1577–78, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456, 105 USPQ 233 (CCPA 1955) (selection of optimum values of known result-effective variables is obvious absent evidence of criticality or unexpected results).
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 20200350159) in further view of Rozbicki et al. (US 7682966 B1).
Regarding claim 13, Li et al. teaches the method of claim 1.
Li et al. doesn’t teach the low-resistance material being ruthenium.
Rozbicki et al. teaches the methods of deposition where the low-resistance material is ruthenium [Col. 4, Lines 40-59, the seed layers can be made from ruthenium].
It would have been obvious to a person with ordinary skill in the art to combine the deposition methods of Li et al. with the deposition methods of Rozbicki et al. because it would have better adhesion and improve the density of the crystal layer as known in the art.
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 20200350159) in further view of Zhang et al. (US 20190074219 A1).
Regarding claim 14, Li et al. teaches the method of claim 1.
Li et al. doesn’t teach the pitch of the barrier layer and low-resistance materials.
Zhang et al. teaches the method of deposition where the semiconductor substrate on which a film of the barrier layer and the low-resistance material is formed is used for a fine pattern with a pitch of less than 28nm [¶0075, conductive lines can be made from ruthenium, titanium, tantalum, or any combination thereof and pitch between conductive lines between about 2nm to about 500nm].
It would have been obvious to a person with ordinary skill in the art before the effective filing date to combine the deposition methods of Li et al. and the pitch range from Zhang et al. because this would make the semiconductor device compact and still retain the desired efficiency from the layers.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (US 20200350159) in further view of Shaviv et al. (US 8298933 B2) and Rozbicki et al. (US 7682966 B1).
Regarding claim 15, Li et al. in view of Shaviv et al. teaches the method of claim 8.
Li et al. in view of Shaviv et al. doesn’t teach the low-resistance material of the seed and crystal layers to be ruthenium.
Rozbicki et al. teaches the deposition method where the low-resistance material used for seed and crystal layers is ruthenium [Col. 4, Lines 40-59, the seed layers can be made from ruthenium].
It would have been obvious to a person with ordinary skill in the art to combine the deposition methods of Li et al. in view of Shaviv et al. with the deposition methods of Rozbicki et al. because it would have better adhesion and improve the density of the crystal layer as known in the art.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NOOR MOHAMMAD ISMAIL TAHIR whose telephone number is (571)272-6166. The examiner can normally be reached Monday Friday, 8 a.m. 5 p.m. ET..
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/NOOR MOHAMMAD ISMAIL TAHIR/Examiner, Art Unit 2893
/SUE A PURVIS/Supervisory Patent Examiner, Art Unit 2893
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