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 .
Status of the Claims
Claims 1-13 are pending and rejected.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 1 and 3-13 are rejected under 35 U.S.C. 103 as being unpatentable over Kirby, US 2011/0217511 A1 in view of Nagy, US 2020/0039892 A1 (provided on the IDS of 5/23/2024) and alternatively further in view of Beckloff, “Large grain polycrystalline silicon via chemical vapor deposition”, 1999, claim 2 is rejected over Kirby in view of Nagy, and Beckloff.
It is noted that the second inventor is used for US 2020/0039892 A1 to differentiate between Kiry references.
Regarding claim 1, 5, and 7, Kirby teaches forming a silicon bond coating on a surface of a substrate by chemical vapor deposition (0016, 0017, 0035, and Fig. 1). They teach that the bond coat layer may generally have a thickness of from about 0.1 mils to about 6 mils, i.e., about 2.54 to 152.4 microns (0017). They teach forming a transition layer on the bond coat layer to form an EBC (0016, 0031, and Fig. 1). They teach that the transition layer comprises a rare earth disilicate (0020), which meets the requirements of claim 5, such that it is considered to be a barrier coating in the EBC coating system. Therefore, they teach forming a silicon bond coating on the surface of a substrate by CVD having a thickness overlapping the range of claims 1 and 7, followed by forming a barrier coating on the bond coating. According to MPEP 2144.05, “in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.”
They do not teach the conditions of the CVD deposition or that the silicon comprises columnar crystalline grains.
Nagy teaches methods for forming a silicon-based bond coating on a surface of a substrate and forming a barrier coating on the silicon-based bond coating (abstract). They teach that the silicon-based bond coating comprises columnar grains of crystalline silicon, where the layer is formed by CVD (abstract). They teach depositing the silicon-based bond coating by CVD at a deposition temperature of about 1100°C to about 1150°C at a pressure of about 115 torr to about 150 torr using a silicon-containing precursor (0011). They teach that the silicon-based bond coating is stronger relative to a bond coating having a crystalline silicon microstructure with very large grains, where the silicon-based bond coating may bond the substrate to the barrier coating (e.g. EBC) thereon, as well as gettering of oxygen without releasing gas to prevent oxidation of the underlying substrate that would otherwise result in a gaseous by-product (0029). They teach using the bond coating in conjunction with a barrier coating to form a coated component with an increased operating temperature compared to that using only a silicon bond coating (0040). They teach that the barrier coating may be a rare earth silicate or disilicate (0040).
From the teachings of Nagy, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Kirby to have used the CVD process of Nagy to deposit a silicon bond coating with a columnar grain structure because Nagy teaches that such a silicon-based bond coating is stronger relative to a bond coating having a crystalline silicon microstructure with very large grains, where the silicon-based bond coating may bond the substrate to the barrier coating thereon, as well as gettering of oxygen without releasing gas to prevent oxidation of the underlying substrate that would otherwise result in a gaseous by-product such that it will be expected to provide a desirable bond coating layer. Therefore, in the process of Kirby in view of Nagy, a silicon bond coating will be formed on a surface of a substrate by CVD of a precursor comprising silicon, the bond coating comprising columnar grains of silicon, where the thickness overlaps the claimed range as noted above (the thickness taught by Kirby).
As noted above, Nagy suggests depositing the columnar silicon film at a temperature of about 1100°C to about 1150°C, which is outside of the claimed range, however, according to MPEP 2144.05 II A, “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have determined the optimum temperature for the deposition process by routine experimentation from the teachings of Kirby in view of Nagy.
Alternatively, Kirby in view of Nagy do not teach using a temperature meeting the claimed requirements. Nagy teaches forming columnar grains of crystalline silicon having an average width of about 1 micron to about 15 microns (0013).
Beckloff teaches forming large grain polycrystalline Si films by CVD using a SiCl4-H2 reagent system (abstract). They teach that grains as large as 15 to 20 microns are achieved for a coating thickness of about 50 microns (abstract). Beckloff teaches that columnar grains are preferred in poly-Si films (pg. 672, section I). They teach that the deposition rate of the films can be increased by using higher deposition temperature and pressures (pg. 672, section I). They teach that Si films have been deposited over a temperature range of 850-1200°C, where highly crystalline films were obtained at higher temperatures (pg. 672, section I). They teach that to obtain large grained polycrystalline Si, the use of high deposition temperature and reduced reactor pressures are needed (pg. 672, section I). They teach that in a study looking at deposition of Si using silane over the range of 950-1250°C, the deposition at low temperature and high deposition rates, micrometer-sized crystallites were formed, where, as deposition temperatures were increased, the deposition rate was decreased and the grain size of the crystallites increased (pg. 672-673, section I). They teach that using trichlorosilane over the same temperature range, the growth mechanism at higher temperatures and slower deposition rates produced larger crystallites, but that using SiHCl3 resulted in grain size smaller and less uniform than using SiH4 (pg. 672-673, section I). They teach depositing various doped polycrystalline silicon films at temperatures of 1200°C, 1250°C, and 1300°C (abstract, pg. 674, section II C, Table I, and Table II). They teach that the process resulted in average grain sizes ranging from 8.3-20.18 microns, where the pressure during the process was 2.8 kPa (pg. 764, section II C and Table III). They teach that the grain structure was columnar, indicating that polycrystalline films formed at temperatures of 1200°C or greater have a columnar structure (pg. 676, section III B, pg. 680, section IV, and Fig. 6). They teach that the temperature, ratio of SiCl4:H2, and the flow rate of the dopant all had an effect on the grain size, where temperature had the highest effect (pg. 679, section III E). Therefore, Beckloff indicates that the deposition temperature and pressure of polycrystalline silicon films affects the deposition rate and grain size, where films deposited at 1200-1300°C have a columnar structure with grain sizes ranging from 8.3-20.18 microns. It is noted that while Beckloff teaches forming doped films, since the dopant is considered to be a small amount and the temperature is indicated as being the dominant feature, similar results are expected for the undoped films.
From the teachings of Beckloff, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Kirby in view of Nagy to have optimized the deposition temperature to be within the claimed range because Beckloff indicates that the deposition temperature and pressure of polycrystalline silicon films affects the deposition rate and grain size, where films deposited at 1200-1300°C have a columnar structure with grain sizes ranging from 8.3-20.18 microns so as to overlap the range desired by Nagy such that it will be expected to provide a desirable columnar crystalline film deposited at a desirable rate with grain sizes in the desired size. According to MPEP 2144.05 II A, “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.”
Regarding claim 2, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Nagy further teaches depositing the silicon film using a pressure of e.g., about 115 Torr to about 150 Torr (0011), i.e., about 15.3 to 20 kPa.
They do not teach using a pressure meeting the claimed range.
Beckloff teaches that the deposition rate of the films can be increased by using higher deposition temperature and pressures (pg. 672, section I). They teach that to obtain large grained polycrystalline Si, the use of high deposition temperature and reduced reactor pressures are needed (pg. 672, section I). They teach that the pressure during the process was 2.8 kPa because when the pressure was 29.3 kPa, the deposition rate was so fast that nearly all of the Si was deposited on the walls of the reactor below the substrate and the reagent stream was severely depleted prior to reaching the substrate (pg. 764, section II C).
From the teachings of Beckloff, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have optimized the pressure to be within the claimed range because Beckloff indicates that columnar crystals are provided at a pressure within the claimed range, where having too high of a pressure increases the deposition rate causing the reagent stream to be depleted before reaching the substrate such that it will be expected to provide the columnar film as desired with a deposition rate that is suitable.
Regarding claim 3, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Nagy further teaches using trichlorosilane as the silicon-containing precursor (0011), such that it will be used as the precursor in the process of Kirby in view of Nagy and alternatively further in view of Beckloff.
Regarding claim 4, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Kirby further teaches forming the transition layer by a slurry deposition cycle, where the slurry includes a solvent (0038-0039), such that the barrier coating will be formed by a liquid deposition process.
Regarding claim 6, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Kirby teaches forming an outer layer 20 which may comprise a rare earth monosilicate, where rare earth elements include ytterbium or yttrium (0018, 0023, and Fig. 1). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the outer coating of ytterbium monosilicate or yttrium monosilicate because Kirby teaches that the outer layer is a rare earth monosilicate, where ytterbium or yttrium are suitable rare earth metals. Therefore, the outer coating is expected to be a protective coating against degradation by CMAS as indicated by [0018] of the instant specification, where ytterbium is in the written compound name and yttrium is in the formula (Y2SiO5).
Regarding claims 8 and 11, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Kirby further teaches that each transition layer may have a thickness of from about 0.1 mils to about 40 mils (0022), i.e., about 2.54 to about 1016 microns. They teach that the structure includes at least one transition layer (0016 and 0022). Therefore, the thickness of the barrier coating layer will overlap the claimed range, for example, when having 1 or 2 transition layers, the lower thickness range will be 2.54 microns or 5.08 microns. According to MPEP 2144.05, “in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.”
Regarding claims 9 and 13, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Kirby further teaches that the EBCs are suitable for use in conjunction with CMCs or monolithic ceramics, where CMCs refer to silicon-containing matrix and reinforcing materials (0014). Therefore, the substrate comprises an at least partially ceramic material and in particular a ceramic matrix composite material.
Regarding claim 10, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Kirby further teaches that the barrier coatings are suitable for use on components used in turbine engines (0015), such that the substrate will form a turbine part or component.
Regarding claim 12, Kirby in view of Nagy and alternatively further in view of Beckloff suggest the process of claim 1. Kirby further teaches that the transition layer comprises a rare earth disilicate (Ln2Si2O7) (0020 and 0021). They teach that “rare earth” represented “(Ln)” refers to elements including ytterbium (0018). From this, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have used ytterbium disilicate as the transition layer or barrier layer because Kirby teaches that ytterbium is a suitable rare earth element and that the transition layer is a rare earth disilicate such that it will be expected to provide a desirable material for the layer.
Response to Arguments
Applicant’s arguments dated 9/30/2025 have been fully considered.
In light of the amendment to the specification, the previous objection has been withdrawn.
In light of the amendments to the claims, the previous 112(b) rejections have been withdrawn.
Regarding the temperature of the process, as discussed above, according to MPEP 2144.05 II A, “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Therefore, the determination of the optimum temperature is considered to be obvious over Kirby in view of Nagy by routine experimentation in the absence of evidence that the temperature is critical. However, an alternate rejection has been provided with the addition of Beckloff, which indicates that a columnar grain structure is provided at higher temperatures with the suggestion to optimize the temperature of the process.
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 CHRISTINA D MCCLURE whose telephone number is (571)272-9761. The examiner can normally be reached Monday-Friday, 8:30-5:00 EST.
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/CHRISTINA D MCCLURE/Examiner, Art Unit 1718 /GORDON BALDWIN/Supervisory Patent Examiner, Art Unit 1718