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 .
Drawings
The drawings are objected to because the following reference character is not mentioned in the description: “110a” in Fig. 2. Appropriate correction of the drawings or amendment of the description to include the omitted reference character is required. See PCT Rule 11.13(l).
The drawings are objected to because Figs. 1 and 2 are described as cross-sectional views in the specification, but the sectional views are not illustrated in accordance with accepted conventions for section representations. See PCT Rule 11.13(b). Appropriate correction of the drawings is required.
Specification
The incorporation by reference of the international patent application PCT/KR2022/003810 and
of the Korean patent application KR10-2021-0036005 is ineffective as it was added on the date of entry into the national phase, which is after the filing date of the instant application. The filing date of this national stage application is the filing date of associated PCT, in this case 3/18/2022, see MPEP 1893.03(b). Therefore, the specification amendment of 9/18/2023 to include the incorporation by reference is new matter, per MPEP 608.01(p).
The disclosure is objected to because of the following informalities: “silicon nitride power” in p. 26, ln. 26, Table 2 and Table 3, which the examiner suggests should be corrected to read “silicon nitride powder.” Appropriate correction is required.
The abstract is objected to because it includes statements such as “excellent plasma resistance, chemical resistance and thermal shock resistance,” “heat dissipation performance of a level equivalent or similar to that of an aluminum nitride ceramic sintered body,” and “can be widely used in a semiconductor process,” which constitute statements of alleged advantages and comparisons with prior art rather than a concise statement of the technical disclosures. Appropriate correction is required. See MPEP 608.01(b).
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are: “cooling member” in claim 13.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
Regarding the term “cooling member” in claim 13, this limitation is interpreted as a means-plus-function limitation because the term “member” is a generic placeholder and the modifier “cooling” merely describes the function to be performed rather than reciting sufficient structure. The recited function is “control[ing] the temperature of the semiconductor wafer … and … cool[ing] the semiconductor wafer heater through the heater unit” (paragraph [0068]). The specification describes the corresponding structure including “a cooling substrate made of aluminum or titanium and a flow path through which coolant can flow inside the cooling substrate” (paragraph [0068]), and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 6 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 6 recites “minimize contamination with metal impurities during pulverizing.” The limitation “to minimize contamination” renders the claim indefinite because the specification does not provide an objective standard by which one of ordinary skill in the art can determine whether a particular pulverizing process satisfies the limitation. The claim does not specify the amount of contamination permitted, the degree of reduction required, a comparison baseline, or any measurable criterion for determining when contamination has been “minimized”.
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 1 and 5-8 and 10 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Aihara et al. (JP 4648030) hereinafter Aihara.
Regarding claim 1, Aihara discloses, in Fig. 1,
an electrostatic chuck (10, “electrostatic chuck”), comprising:
a silicon nitride sintered body (11, “substrate”; Aihara (translation), p. 3, lns. 12-13: “the substrate is formed of the yttria sintered body”; p. 2, ln. 25: “yttria sintered body … containing … silicon nitride”; the examiner interprets Aihara as teaching the silicon nitride containing sintered body corresponding to the “silicon nitride sintered body”) formed by sintering silicon nitride powder (Aihara (translation), p. 3, lns. 30-31: “[t]he method for producing a yttria sintered body [forming the substrate] … includes a step of producing a raw material powder containing … silicon nitride”); and
an electrostatic electrode (12, “electrostatic electrode”) buried inside the silicon nitride sintered body (11) (Fig. 1 shows the configuration).
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Fig. 1 of Nagasaki
Regarding claim 5, claim 5 is a product-by-process claim. That is, the claimed steps of manufacturing a mixed raw material powder ..., producing granules ..., nitriding the granules …, and pulverizing the nitrided granules are steps that describe the method of producing the electrostatic chuck of claim 1. "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." MPEP 2113. Accordingly, Aihara anticipates claim 5, since Aihara discloses all of the structure of the electrostatic chuck of claim 1, as described in the rejection of claim 1.
Regarding claims 6-8 and 10, Aihara anticipates claims 6-10 for the same reason set forth above with respect to claim 5. The additional limitations of claims 6-10 further define process conditions, raw materials, particle sizes, granule characteristics, additive concentrations, and nitriding conditions used in producing the silicon nitride powder, but the claims do not recite additional structural limitations of the electrostatic chuck itself beyond those already recited in claim 1. Accordingly, the patentability of claims 6-10 is determined based on the electrostatic chuck product itself rather than the recited manufacturing process. See MPEP 2113.
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 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.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Lee et al. (US 4234661) hereinafter Lee.
Regarding claim 2, Aihara teaches the electrostatic chuck (10) of claim 1 comprising the silicon nitride sintered body (11), but does not explicitly teach the silicon nitride sintered body contains 9% by weight or less of polycrystalline silicon.
However, Lee teaches a silicon nitride sintered body (col. 7, lns. 36-37: “sintered body comprised of silicon nitride”) contains 9% by weight or less of polycrystalline silicon (col. 15, lns. 22-30: “The polycrystalline silicon nitride substrate … comprised, by weight of the silicon nitride hot-pressed body, of … 2% free Si”; the examiner interprets the disclosed “2% free Si” in the polycrystalline silicon nitride substrate as corresponding to the claimed polycrystalline silicon contained in the silicon nitride sintered body, wherein the disclosed 2 weight % is within the claimed limitation of “9% by weight or less”).
Aihara and Lee are considered to be analogous to the claimed invention because they are in the same field of producing silicon nitride substrate composite. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have the silicon nitride sintered body of Aihara contain 9% by weight or less of polycrystalline silicon as taught by Lee, in order to provide a silicon nitride substrate having “a thermally stable strong bond”, “stability in form … [and] sufficient strength”, as well as “well-bonded hard[ness]” (Lee, col. 1, ln. 19; col. 2, lns. 36-37; col. 23, ln. 26), thereby improving the material characteristics and durability of the silicon nitride sintered body.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Yamamoto et al. (US 5204297) hereinafter Yamamoto.
Regarding claim 3, Aihara teaches the electrostatic chuck (10) of claim 1, wherein the silicon nitride sintered body (11) is formed by sintering silicon nitride powder (Aihara (translation), p. 3, lns. 30-31), but does not explicitly teach silicon nitride powder in which a weight ratio of an α crystal phase is 0.7 or more in a total weight of the α crystal phase and a β crystal phase.
However, Yamamoto teaches silicon nitride powder (col. 2, lns. 37-38: “a Si3N4 source powder having a percentage α crystallization of 93% or more”) in which a weight ratio of an α crystal phase is 0.7 or more in a total weight of the α crystal phase and a β crystal phase (col. 2, lns. 20-23: “sintered body comprising crystal phases containing both an α-Si3N4 crystal phase and a β’-sialon crystal phase, the relative density of the sintered body being 98% or more,” from which the examiner interprets the disclosed predominance of the α-Si3N4 crystal phase corresponding to the disclosed crystallization percentage of 93% or more as teaching a weight ratio of an α crystal phase of 0.7 or more in total weight of the α crystal phase and β crystal phase).
Aihara and Yamamoto are considered to be analogous to the claimed invention because they are in the same field of producing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to form the silicon nitride sintered body of Aihara by the composition of α crystal phase and a β crystal phase as taught by Yamamoto, for the purpose of ensuring “the relative density of the sintered body being 98% or more” (Yamamoto, col. 2, lns. 22-23), in order to “stably provide a sintered body having a high strength on an industrial scale without limitation” (Yamamoto, col. 3, lns. 47-49).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Kim et al. (US 20180237347) hereinafter Kim.
Regarding claim 4, Aihara teaches the electrostatic chuck (10) of claim 1 comprising the silicon nitride sintered body (11), but does not explicitly teach the silicon nitride sintered body has a thermal conductivity of 70 W/mK or more and a three-point bending strength of 650 MPa or more.
However, Kim teaches a silicon nitride sintered body (abstract: “silicon nitride sintered body”) has a thermal conductivity of 70 W/mK or more and a three-point bending strength of 650 MPa or more (paragraph [0018]: “the silicon nitride … sintered body has a high mechanical strength of about 660 to 870 MPa and a high thermal conductivity of 70 W/mK or more”).
Aihara and Kim are considered to be analogous to the claimed invention because they are in the same field of manufacturing a silicon nitride body with high thermal conductivity. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate the silicon nitride sintered body having the properties including the thermal conductivity and the three-point bending strength as taught by Kim into the electrostatic chuck of Aihara, for the purpose of ensure “excellent thermal and mechanical properties as well as high thermal conductivity, and thus [the silicon nitride sintered body] can be used for various purposes” (Kim, paragraph [0019]).
*Note: The rejections below directed to claims 5-8 and 10 are not intended to supersede the anticipatory product by process rejections made above. Examiner has provided them in an effort to further advance prosecution.
Claims 5 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Imamura et al. (US 20190031566) hereinafter Imamura, and further in view of Park et al. (KR 20110083009) hereinafter Park.
Regarding claim 5, Aihara teaches the electrostatic chuck (10) of claim 1, wherein the silicon nitride sintered body (11) is formed by sintering silicon nitride powder (Aihara (translation), p. 3, lns. 30-31), but does not explicitly teach the silicon nitride powder is manufactured by processes comprising:
manufacturing a mixed raw material powder containing a metallic silicon powder, and a crystal phase control powder containing a rare earth element-containing compound and a magnesium-containing compound;
producing granules having a predetermined particle diameter by mixing the mixed raw material powder with a solvent and an organic binder to form a slurry and then spray drying;
nitriding the granules at a predetermined temperature within a range of 1200 °C to 1500 °C while applying nitrogen gas at a predetermined pressure, to obtain nitrided granules; and pulverizing the nitrided granules.
However, Imamura teaches a silicon nitride powder is manufactured by processes (paragraph [0001]: “method for producing the silicon nitride sintered substrate”) comprising:
manufacturing a mixed raw material powder (“material powder”) containing a metallic silicon powder (“Si powder”) (paragraph [0071]: “the material powder contains the Si powder”), and a crystal phase control powder containing a rare earth element-containing compound and a magnesium-containing compound (paragraph [0071]: “Mg compound powder … and … rare earth element compound powder”; paragraph [0070]: “sintering additive is a combination of MgO powder and Y2O3 powder”; paragraph [0113]: “the crystallization of the sintering additive”; the examiner interprets Imamura as teaching the claimed crystal phase control powder because the disclosed sintering additive includes Mg compound powder and rare earth element compound powder for controlling formation and crystallization of the grain boundary phase during sintering);
mixing the mixed raw material powder with a solvent (“organic solvent”) and an organic binder (“organic binder”) to form a slurry (“slurry”) (paragraph [0077]: “The material powder … is mixed with … an organic binder … and an organic solvent … to form a slurry”);
nitriding material formed from the slurry (paragraph [0079]: “After the slurry is defoamed and made viscous, the greensheet is formed by … a doctor blade method”) at a predetermined temperature within a range of 1200 °C to 1500 °C (paragraph [0103]: “the atmosphere temperature in the sintering furnace is raised and is maintained at temperature Tn in the range of 1350° C. or higher and 1450° C. or lower … the Si powder reacts with nitrogen, which is the atmosphere in the sintering furnace, to generate silicon nitride.”) while applying nitrogen gas at a predetermined pressure (paragraph [0102]: “the pressure in the sintering furnace is 1 atmospheric pressure or higher and about 20 atmospheric pressure or lower”), to obtain nitrided material (paragraph [0103]: “to generate silicon nitride”).
Aihara and Imamura are considered to be analogous to the claimed invention because they are in the same field of method for producing the silicon nitride sintered substrate. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the manufacturing process of the silicon nitride powder as taught by Imamura in forming the silicon nitride sintered body of Aihara, in order to “provide a [various]-sized silicon nitride sintered substrate having a high insulation reliability” (Imamura, paragraph [0020]), thereby improving the insulation reliability and manufacturability of the silicon nitride sintered body.
Regarding claim 5, Aihara and Imamura does not explicitly teach the processes comprising:
producing granules from the slurry by spray drying;
nitriding the granules to obtain nitride granules; and
pulverizing the nitride granules.
However, Park teaches a process (Park (translation), p. 1, ln. 12: “method of manufacturing [a silicon nitride sintered body]”) comprising:
producing granules (p. 2, ln. 36: “granular powder”) from the slurry (p. 2, ln. 49: “spray slurry”) by spray drying (p. 2, ln. 49: “The spray slurry was prepared by planetary milling”; p. 2, ln. 36: “granulated powder was prepared by spray drying”; p. 3, ln. 1: “As a result of spray drying, coarse granules … were formed”; the examiner interprets Park as teaching that the spray slurry prepared beforehand is processed by spray drying to produce the claimed granules);
nitriding the granules (“granular powder”) to obtain nitride granules (p. 3, ln. 34: “[h]igh melting point YA-based granules … were sintered by nitriding at 1300 ° C-6h,” which the examiner interprets as resulting in nitride granules); and
pulverizing the nitride granules (p. 3, lns. 41-42: “the sintering in the granules as well as … between the granules proceeded by nitriding and sintering, … most of the spherical granules were broken in an angular form by grinding,” which the examiner interprets as teaching that the granules are pulverized after being nitrided).
Aihara, Imamura and Park are considered to be analogous to the claimed invention because they are in the same field of a method of manufacturing silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the process of producing and processing the granular powder as taught by Park in forming the silicon nitride sintered body taught by Aihara and Imamura, in order to “promote[] nitriding reaction and sintering of silicon” (Park (translation), p. 2, ln. 37).
Regarding claim 8, Aihara in view of Imamura and Park teaches the electrostatic chuck (Aihara: 10) of claim 5, wherein the granules (Park: “granular powder”) have a D50 value (Park: “median particle diameter”) of 20 um to 55 um (Park (translation), p. 3, ln. 30: “The granular powder used in this example has a median particle diameter of 38.5 μm”).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Imamura et al. (US 20190031566) hereinafter Imamura, Park et al. (KR 20110083009) hereinafter Park, and further in view of Zhao et al. (CN 111086991) hereinafter Zhao.
Regarding claim 6, Aihara in view of Imamura and Park teaches the electrostatic chuck (Aihara: 10) of claim 5, wherein the metallic silicon powder is pulverized nitride granules including Si powder, as discussed in the claim 5 rejection (Imamura, paragraph [0071]; Park (translation), p. 3, lns. 41-42).
Aihara, Imamura and Park does not explicitly teach the metallic silicon powder is dry-pulverized polycrystalline metallic silicon scrap or single crystal silicon wafer scrap to minimize contamination with metal impurities during pulverizing.
However, Zhao teaches,
the metallic silicon powder is dry-pulverized (Zhao (translation), p. 4, ln. 21: “dry ball milling”) polycrystalline metallic silicon scrap or single crystal silicon wafer scrap (Zhao (translation), p. 2, ln. 9: “photovoltaic industrial silicon waste”) (p. 2, ln. 20: “Most of silicon powder produced by cutting a silicon wafer by diamond wires in a multi-wire mode,” which the examiner interprets the recovered silicon waste from wafer cutting as corresponding to the claimed metallic silicon scrap)
to minimize contamination with metal impurities during pulverizing (abstract: “utilizing photovoltaic industrial silicon wastes… characterized in that the content of impurity elements is controlled”; p. 2, lns. 23-24: “the multistage ball milling method is high in energy consumption and many in impurities”; p. 4, lns. 4-5: “when the small-particle silicon suspension passes through a group of magnetic separators, iron and nickel impurities caused by abrasion of diamond wires can be removed”; the examiner interprets Zhao as teaching dry pulverization and impurity-reduction processing for minimizing metallic contamination during pulverizing).
Aihara, Imamura, Park and Zhao are considered to be analogous to the claimed invention because they are in the same field of producing and processing silicon containing materials for silicon nitride sintered bodies. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the dry-pulverization process using polycrystalline metallic silicon scrap or single crystal silicon wafer scrap as taught by Zhao in the silicon powder preparation process taught by Imamura and Park in forming the silicon nitride sintered body of Aihara, in order to ensure that “the resource utilization of the silicon waste is realized through a series of treatment processes, so that the waste of resources is avoided” (Zhao (translation), p. 3, lns. 18-19), thereby utilizing recycled silicon waste materials while minimizing contamination with metal impurities during pulverizing (Zhao (translation), abstract: “a method … characterized in that the content of impurity elements is controlled”).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Imamura et al. (US 20190031566) hereinafter Imamura, Park et al. (KR 20110083009) hereinafter Park, Zhao et al. (CN 111086991) hereinafter Zhao, and further in view of Yamamoto et al. (US 5204297) hereinafter Yamamoto.
Regarding claim 7, Aihara in view of Imamura, Park and Zhao teaches the electrostatic chuck (Aihara: 10) of claim 5, wherein the metallic silicon powder has an average particle diameter of 0.5 um to 4 um (Zhao (translation), p. 2, lns. 20-21: “Most of silicon powder produced by cutting a silicon wafer by diamond wires in a multi-wire mode is of a flaky structure with the dimensions of nanoscale thickness (50-150 nm) and submicron or micron-scale length (0.3-3 microns), and can be called as micro-nano silicon powder,” which the examiner interprets as corresponding to the claimed metallic silicon powder, and Zhao’s disclosed submicron or micron-scale length of 0.3-3 um overlaps the claimed average particle diameter range of 0.5-4 um),
Aihara, Imamura, Park and Zhao does not explicitly teach rare earth element-containing compound powder has an average particle diameter of 0.1 um to 1 um, and magnesium-containing compound powder has an average particle diameter of 0.1 um to 1 um.
However, Yamamoto teaches a silicon nitride sintered body (abstract: “silicon nitride sintered body”) wherein
rare earth element-containing compound powder has an average particle diameter of 0.1 um to 1 um (col. 6, ln. 47-48: “powder of Y2O3 … having mean grain diameter of 0.8 um”), and
magnesium-containing compound powder has an average particle diameter of 0.1 um to 1 um (col. 6, ln. 47-48: “powder of … MgO having mean grain diameters of … 0.5 um”).
Aihara, Imamura, Park, Zhao and Yamamoto are considered to be analogous to the claimed invention because they are in the same field of producing and processing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to include the rare earth element-containing compound powder and the magnesium-containing compound powder having the particle size ranges taught by Yamamoto in the metallic silicon powder of Aihara, Imamura, Park and Zhao for forming the silicon nitride sintered body, for the purpose of ensuring “the relative density of the sintered body being 98% or more” (Yamamoto, col. 2, lns. 22-23), in order to “stably provide a sintered body having a high strength on an industrial scale without limitation” (Yamamoto, col. 3, lns. 47-49), thereby improving the density and strength properties of the resulting silicon nitride sintered body.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Imamura et al. (US 20190031566) hereinafter Imamura, Park et al. (KR 20110083009) hereinafter Park, further in view of Yamamoto et al. (US 5204297) hereinafter Yamamoto.
Regarding claim 9, Aihara in view of Imamura and Park teaches the electrostatic chuck (Aihara: 10) of claim 5, wherein
the rare earth element-containing compound is yttrium oxide, and the magnesium-containing compound is magnesium oxide (Imamura, paragraph [0071]: “Mg compound powder … and … rare earth element compound powder”; paragraph [0070]: “sintering additive is a combination of MgO powder and Y2O3 powder”).
Aihara, Imamura and Park does not explicitly teach the mixed raw material powder contains 2 mol% to 5 mol% of yttrium oxide and 2 mol% to 10 mol% of magnesium oxide.
However, Yamamoto teaches a silicon nitride sintered body (abstract: “silicon nitride sintered body”) wherein
mixed raw material powder contains 2 mol% to 5 mol% of yttrium oxide (Table 1 teaches Y2O3 composition ranging between 1.2 and 6.1 % by mole, overlapping the claimed 2-5 mol%) and 2 mol% to 10 mol% of magnesium oxide (Table 1 teaches MgO composition ranging between 1.6 to 10.0 % by mole overlapping the claimed 2-10 mol%).
MPEP 2144.05 (I) states, “[i]n the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.”
Aihara, Imamura, Park and Yamamoto are considered to be analogous to the claimed invention because they are in the same field of producing and processing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the overlapping mol% ranges of yttrium oxide and magnesium oxide taught by Yamamoto in the mixed raw material powder of Aihara in view of Imamura and Park, because the additive composition amounts are recognized result-effective variables in preparing silicon nitride sintered bodies. Such optimization through routine experimentation would have predictably yielded “the relative density of the sintered body being 98% or more” (Yamamoto, col. 2, lns. 22-23), in order to “stably provide a sintered body having a high strength on an industrial scale without limitation” (Yamamoto, col. 3, lns. 47-49), thereby improving the density and strength properties of the resulting silicon nitride sintered body.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Aihara et al. (JP 4648030) hereinafter Aihara, in view of Imamura et al. (US 20190031566) hereinafter Imamura, Park et al. (KR 20110083009) hereinafter Park, further in view of Yamao et al. (US 20170107109) hereinafter Yamao.
Regarding claim 10, Aihara in view of Imamura and Park teaches the electrostatic chuck (Aihara: 10) of claim 5, but does not explicitly teach
during nitriding, a temperature is heated from 1000 °C or higher to the predetermined temperature at a temperature increase rate of 0.5 °C/min to 10 °C/min, and the nitrogen gas is applied at a pressure of 0.1 MPa to 0.2 MPa.
However, Yamao teaches a production method for a silicon nitride powder, wherein a temperature is heated from 1000 °C or higher to the predetermined temperature at a temperature increase rate of 0.5 °C/min to 10 °C/min (paragraph [0031]: “a nitrogen-containing inert gas … the amorphous Si—N(—H)-based compound is heated at a temperature rising rate of 250 to 1,000° C./hour in the temperature range of 1,000 to 1,400° C”; the temperature rising rate of 250 to 1,000 °C/hour is converted to 4.17 to 16.7 °C/min, overlapping the claimed range of 0.5 to 10 °C/min), and the nitrogen gas is applied at a pressure of 0.1 MPa to 0.2 MPa (paragraph [0061]: “gas pressure sintering where the gas pressure in an inert gas atmosphere such as nitrogen … is raised to approximately from 0.2 to 10 MPa,” overlapping the claimed range of 0.1 to 0.2 MPa).
MPEP 2144.05 (I) states, “[i]n the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.”
Aihara, Imamura, Park and Yamao are considered to be analogous to the claimed invention because they are in the same field of producing and processing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the overlapping temperature rising rate and nitrogen gas pressure conditions as taught by Yamao in the nitriding process taught by Aihara, Imamura and Park, since the heating rate and gas pressure are recognized result-effective variables in producing silicon nitride powder and silicon nitride sintered bodies. Such optimization through routine experimentation would have predictably yielded improved nitriding and sintering characteristics, in order to “obtain a dense silicon nitride sintered body having both an excellent mechanical strength and high thermal conductivity” (Yamao, paragraph [0036]).
Claims 11-12 and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara.
Regarding claim 11, Ishida teaches, in Fig. 1,
an electrostatic chuck heater (10, “substrate”; Ishida (translation), p. 4, ln. 17: “electrostatic chuck with a heater,” which the examiner interprets as corresponding to the substrate 10) having a first surface (11, “first substrate portion”) on which a wafer is adsorbed (Ishida (translation), p. 4, lns. 22-23: “the first substrate portion 11 constitutes a mounting surface S on which the semiconductor wafer is mounted”) and a second surface (12, “second substrate portion”) opposing the first surface (11), the electrostatic chuck heater (10) comprising:
an electrostatic chuck unit (10) comprising a first ceramic sintered body (“ceramic sintered body”; p. 4, lns. 18-19: “a first substrate portion 11 … made of a ceramic sintered body”) and an electrostatic electrode (21, “electrostatic chuck electrode”) buried inside the first ceramic sintered body (“ceramic sintered body”) (p. 4, ln. 21: “The first base portion 11 is configured by integral firing with the electrostatic chuck electrode 21 embedded therein”; Fig. 1 also teaches the configuration), wherein the first ceramic sintered body is the first surface (11) (p. 4, lns. 18-19), and
a heater unit (22, “heating resistor”) comprising a second ceramic sintered body (p. 4, lns. 18-19: “a second substrate portion 12 made of a ceramic sintered body”) and at least one resistance heating element (22) buried inside the second ceramic sintered body (“ceramic sintered body”) (p. 4, ln. 26: “The second base portion 12 is configured by being integrally fired in a state where the heating resistor 22 is embedded”; Fig. 1 also teaches the configuration), wherein the second ceramic sintered body is the second surface (12) (p. 4, lns. 18-19).
Regarding claim 11, Ishida does not explicitly teach at least one of the first ceramic sintered body and the second ceramic sintered body is a silicon nitride sintered body formed by sintering silicon nitride powder.
However, Aihara teaches, in Fig. 1, an electrostatic chuck (10, “electrostatic chuck”), wherein
at least one of the first ceramic sintered body and the second ceramic sintered body is a silicon nitride sintered body (11, “substrate”; Aihara (translation), p. 3, lns. 12-13: “the substrate is formed of the yttria sintered body”; p. 2, ln. 25: “yttria sintered body … containing … silicon nitride”; the examiner interprets Aihara as teaching the silicon nitride containing sintered body corresponding to the “silicon nitride sintered body”) formed by sintering silicon nitride powder (Aihara (translation), p. 3, lns. 30-31: “[t]he method for producing a yttria sintered body [forming the substrate] … includes a step of producing a raw material powder containing … silicon nitride”).
Ishida and Aihara are considered to be analogous to the claimed invention because they are in the same field of electrostatic chucks and heaters. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to form at least one ceramic sintered body of Ishida using a silicon nitride-containing sintered ceramic material as taught by Aihara, in order to obtain “an electrostatic chuck excellent in corrosion resistance and mechanical strength.” Aihara (translation), p. 3, lns. 7-8.
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Fig. 1 of Ishida
Regarding claim 12, Ishida in view of Aihara teaches the electrostatic chuck heater (Ishida: 10) of claim 11, wherein the first ceramic sintered body (Ishida: 11) and the second ceramic sintered body (Ishida: 12) are simultaneously sintered and implemented as one body (Ishida (translation), p. 8, lns. 40-41: “The first raw material powder compact in which the electrostatic chuck electrode is embedded and the second raw material powder compact in which the heating resistor is embedded are superposed and hot-press sintered together”; p. 9, ln. 18: “the compact was sintered by a hot press sintering method”; p. 4, lns. 18-19: “The substrate 1[0] is configured by integrating a first substrate portion 11 and a second substrate portion 12 … without a gap”; the examiner interprets Ishida as teaching the first ceramic sintered body and the second ceramic sintered body being simultaneously sintered and implemented as one body).
Regarding claim 17, claim 17 is a product-by-process claim. That is, the claimed steps of manufacturing a mixed raw material powder ..., producing granules ..., nitriding the granules …, and pulverizing the nitrided granules are steps that describe the method of producing the electrostatic chuck heater of claim 11. "[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." MPEP 2113. Accordingly, Ishida and Aihara renders claim 17 obvious, since Ishida and Aihara teaches all of the structure of the electrostatic chuck heater of claim 11, as described in the rejection of claim 11.
Regarding claims 18-20, Ishida in view of Aihara renders claims 18-20 obvious for the same reason set forth above with respect to claim 17. The additional limitations of claims 18-20 further define process conditions, raw materials, particle sizes, granule characteristics, additive concentrations, and nitriding conditions used in producing the silicon nitride powder, but the claims do not recite additional structural limitations of the electrostatic chuck heater itself beyond those already recited in claim 11. Accordingly, the patentability of claims 18-20 is determined based on the electrostatic chuck heater product itself rather than the recited manufacturing process. See MPEP 2113.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, and further in view of Sugimoto (JP 4986830).
Regarding claim 13, Ishida in view of Aihara teaches a semiconductor holding device (Ishida (translation), p. 4, ln. 17: “electrostatic chuck with a heater”; p. 4, lns. 22-23: “the first substrate portion 11 constitutes a mounting surface S on which the semiconductor wafer is mounted”; the examiner interprets Ishida as teaching the claimed semiconductor holding device), comprising: the electrostatic chuck heater according to claim 11 (Ishida: 10), but does not explicitly teach a cooling member disposed on the second surface of the electrostatic chuck heater.
However, Sugimoto teaches, in Fig. 1, a semiconductor holding device (10, “substrate holder”), comprising:
a cooling member (20, “second substrate” including a flow path 22 for coolant) disposed on the second surface of the electrostatic chuck heater (12, “first base”; Fig. 2 shows the second substrate 20 disposed on the second/bottom surface of the first base 12) (Sugimoto (translation), p. 3, lns. 20-21: “A spiral groove is provided on the upper surface of the second substrate 20 as a flow path 22 through which a coolant for cooling the substrate to be processed placed on the upper surface of the first substrate 12 flows”).
Ishida, Aihara and Sugimoto are considered to be analogous to the claimed invention because they are in the same field of a manufacturing process of electrostatic chucks. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate the coolant-flow second substrate structure as taught by Sugimoto into the electrostatic chuck heater of Ishida and Aihara, in order to “suppress a decrease in cooling efficiency and … reduce manufacturing costs.” Sugimoto (translation), p. 2, lns. 35-36.
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Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, and further in view of Lee et al. (US 4234661) hereinafter Lee.
Regarding claim 14, Ishida and Aihara teaches the electrostatic chuck heater (Ishida: 10) of claim 11, comprising the silicon nitride sintered body (Aihara: 11), but does not explicitly teach the silicon nitride sintered body contains 9% by weight or less of polycrystalline silicon.
However, Lee teaches a silicon nitride sintered body (col. 7, lns. 36-37: “sintered body comprised of silicon nitride”) contains 9% by weight or less of polycrystalline silicon (col. 15, lns. 22-30: “The polycrystalline silicon nitride substrate … comprised, by weight of the silicon nitride hot-pressed body, of … 2% free Si”; the examiner interprets the disclosed “2% free Si” in the polycrystalline silicon nitride substrate as corresponding to the claimed polycrystalline silicon contained in the silicon nitride sintered body, wherein the disclosed 2 weight % is within the claimed limitation of “9% by weight or less”).
Ishida, Aihara and Lee are considered to be analogous to the claimed invention because they are in the same field of producing silicon nitride substrate composite. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have the silicon nitride sintered body of Ishida and Aihara contain 9% by weight or less of polycrystalline silicon as taught by Lee, in order to provide a silicon nitride substrate having “a thermally stable strong bond”, “stability in form … [and] sufficient strength”, as well as “well-bonded hard[ness]” (Lee, col. 1, ln. 19; col. 2, lns. 36-37; col. 23, ln. 26), thereby improving the material characteristics and durability of the silicon nitride sintered body.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, and further in view of Yamamoto et al. (US 5204297) hereinafter Yamamoto.
Regarding claim 15, Ishida and Aihara teaches the electrostatic chuck heater (Ishida: 10) of claim 11, comprising the silicon nitride sintered body (Aihara: 11), but does not explicitly teach the silicon nitride sintered body is formed by sintering silicon nitride powder in which a weight ratio of an α crystal phase is 0.7 or more in a total weight of the α crystal phase and a β crystal phase.
However, Yamamoto teaches silicon nitride powder (col. 2, lns. 37-38: “a Si3N4 source powder having a percentage α crystallization of 93% or more”) in which a weight ratio of an α crystal phase is 0.7 or more in a total weight of the α crystal phase and a β crystal phase (col. 2, lns. 20-23: “sintered body comprising crystal phases containing both an α-Si3N4 crystal phase and a β’-sialon crystal phase, the relative density of the sintered body being 98% or more,” from which the examiner interprets the disclosed predominance of the α-Si3N4 crystal phase corresponding to the disclosed crystallization percentage of 93% or more as teaching a weight ratio of an α crystal phase of 0.7 or more in total weight of the α crystal phase and β crystal phase).
Ishida, Aihara and Yamamoto are considered to be analogous to the claimed invention because they are in the same field of producing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to form the silicon nitride sintered body of Ishida and Aihara by the composition of α crystal phase and a β crystal phase as taught by Yamamoto, for the purpose of ensuring “the relative density of the sintered body being 98% or more” (Yamamoto, col. 2, lns. 22-23), in order to “stably provide a sintered body having a high strength on an industrial scale without limitation” (Yamamoto, col. 3, lns. 47-49).
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, and further in view of Kim et al. (US 20180237347) hereinafter Kim.
Regarding claim 16, Ishida and Aihara teaches the electrostatic chuck heater (Ishida: 10) of claim 11, comprising the silicon nitride sintered body (Aihara: 11), but does not explicitly teach the silicon nitride sintered body has a thermal conductivity of 70 W/mK or more and a three-point bending strength of 650 MPa or more.
However, Kim teaches a silicon nitride sintered body (abstract: “silicon nitride sintered body”) has a thermal conductivity of 70 W/mK or more and a three-point bending strength of 650 MPa or more (paragraph [0018]: “the silicon nitride … sintered body has a high mechanical strength of about 660 to 870 MPa and a high thermal conductivity of 70 W/mK or more”).
Ishida, Aihara and Kim are considered to be analogous to the claimed invention because they are in the same field of manufacturing a silicon nitride body with high thermal conductivity. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate the silicon nitride sintered body having the properties including the thermal conductivity and the three-point bending strength as taught by Kim into the electrostatic chuck of Ishida and Aihara, for the purpose of ensure “excellent thermal and mechanical properties as well as high thermal conductivity, and thus [the silicon nitride sintered body] can be used for various purposes” (Kim, paragraph [0019]).
Claims 17 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, Imamura et al. (US 20190031566) hereinafter Imamura, and further in view of Park et al. (KR 20110083009) hereinafter Park.
Regarding claim 17, Ishida and Aihara teaches the electrostatic chuck (Ishida: 10) of claim 11, wherein the silicon nitride sintered body (Aihara: 11) is formed by sintering silicon nitride powder (Aihara (translation), p. 3, lns. 30-31), but does not explicitly teach the silicon nitride powder is manufactured by processes comprising:
manufacturing a mixed raw material powder containing a metallic silicon powder, and a crystal phase control powder containing a rare earth element-containing compound and a magnesium-containing compound;
producing granules having a predetermined particle diameter by mixing the mixed raw material powder with a solvent and an organic binder to form a slurry and then spray drying;
nitriding the granules at a predetermined temperature within a range of 1200 to 1500 °C while applying nitrogen gas at a predetermined pressure, to obtain nitrided granules; and pulverizing the nitrided granules.
However, Imamura teaches a silicon nitride powder is manufactured by processes (paragraph [0001]: “method for producing the silicon nitride sintered substrate”) comprising:
manufacturing a mixed raw material powder (“material powder”) containing a metallic silicon powder (“Si powder”) (paragraph [0071]: “the material powder contains the Si powder”), and a crystal phase control powder containing a rare earth element-containing compound and a magnesium-containing compound (paragraph [0071]: “Mg compound powder … and … rare earth element compound powder”; paragraph [0070]: “sintering additive is a combination of MgO powder and Y2O3 powder”; paragraph [0113]: “the crystallization of the sintering additive”; the examiner interprets Imamura as teaching the claimed crystal phase control powder because the disclosed sintering additive includes Mg compound powder and rare earth element compound powder for controlling formation and crystallization of the grain boundary phase during sintering);
mixing the mixed raw material powder with a solvent (“organic solvent”) and an organic binder (“organic binder”) to form a slurry (“slurry”) (paragraph [0077]: “The material powder … is mixed with … an organic binder … and an organic solvent … to form a slurry”);
nitriding material formed from the slurry (paragraph [0079]: “After the slurry is defoamed and made viscous, the greensheet is formed by … a doctor blade method”) at a predetermined temperature within a range of 1200 °C to 1500 °C (paragraph [0103]: “the atmosphere temperature in the sintering furnace is raised and is maintained at temperature Tn in the range of 1350° C. or higher and 1450° C. or lower … the Si powder reacts with nitrogen, which is the atmosphere in the sintering furnace, to generate silicon nitride.”) while applying nitrogen gas at a predetermined pressure (paragraph [0102]: “the pressure in the sintering furnace is 1 atmospheric pressure or higher and about 20 atmospheric pressure or lower”), to obtain nitrided material (paragraph [0103]: “to generate silicon nitride”).
Ishida, Aihara and Imamura are considered to be analogous to the claimed invention because they are in the same field of method for producing the silicon nitride sintered substrate. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the manufacturing process of the silicon nitride powder as taught by Imamura in forming the silicon nitride sintered body of Ishida and Aihara, in order to “provide a [various]-sized silicon nitride sintered substrate having a high insulation reliability” (Imamura, paragraph [0020]), thereby improving the insulation reliability and manufacturability of the silicon nitride sintered body.
Regarding claim 17, Ishida in view of Aihara and Imamura does not explicitly teach the processes comprising:
producing granules from the slurry by spray drying;
nitriding the granules to obtain nitride granules; and
pulverizing the nitride granules.
However, Park teaches a process (Park (translation), p. 1, ln. 12: “method of manufacturing [a silicon nitride sintered body]”) comprising:
producing granules (p. 2, ln. 36: “granular powder”) from the slurry (p. 2, ln. 49: “spray slurry”) by spray drying (p. 2, ln. 49: “The spray slurry was prepared by planetary milling”; p. 2, ln. 36: “granulated powder was prepared by spray drying”; p. 3, ln. 1: “As a result of spray drying, coarse granules … were formed”; the examiner interprets Park as teaching that the spray slurry prepared beforehand is processed by spray drying to produce the claimed granules);
nitriding the granules (“granular powder”) to obtain nitride granules (p. 3, ln. 34: “[h]igh melting point YA-based granules … were sintered by nitriding at 1300 ° C-6h,” which the examiner interprets as resulting in nitride granules); and
pulverizing the nitride granules (p. 3, lns. 41-42: “the sintering in the granules as well as … between the granules proceeded by nitriding and sintering, … most of the spherical granules were broken in an angular form by grinding,” which the examiner interprets as teaching that the granules are pulverized after being nitrided).
Ishida, Aihara, Imamura and Park are considered to be analogous to the claimed invention because they are in the same field of a method of manufacturing silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the process of producing and processing the granular powder as taught by Park in forming the silicon nitride sintered body taught by Ishida, Aihara and Imamura, in order to “promote[] nitriding reaction and sintering of silicon” (Park (translation), p. 2, ln. 37).
Regarding claim 19, Ishida in view of Aihara, Imamura and Park teaches the electrostatic chuck heater (Ishida: 10) of claim 17, wherein the granules (Park: “granular powder”) have a D50 value (Park: “median particle diameter”) of 20 um to 55 um (Park (translation), p. 3, ln. 30: “The granular powder used in this example has a median particle diameter of 38.5 μm”).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, Imamura et al. (US 20190031566) hereinafter Imamura, Park et al. (KR 20110083009) hereinafter Park, Zhao et al. (CN 111086991) hereinafter Zhao, and further in view of Yamamoto et al. (US 5204297) hereinafter Yamamoto.
Regarding claim 18, Ishida in view of Aihara, Imamura and Park teaches the electrostatic chuck heater (Ishida: 10) of claim 17, wherein the silicon nitride sintered body (Aihara: 11) is formed by sintering silicon nitride powder (Aihara (translation), p. 3, lns. 30-31) containing the metallic silicon powder (Imamura: “Si powder”), but does not explicitly teach the metallic silicon powder has an average particle diameter of 0.5 um to 4 um.
However, Zhao teaches metallic silicon powder has an average particle diameter of 0.5 um to 4 um (Zhao (translation), p. 2, lns. 20-21: “Most of silicon powder produced by cutting a silicon wafer by diamond wires in a multi-wire mode is of a flaky structure with the dimensions of nanoscale thickness (50-150 nm) and submicron or micron-scale length (0.3-3 microns), and can be called as micro-nano silicon powder,” which the examiner interprets as corresponding to the claimed metallic silicon powder, and Zhao’s disclosed submicron or micron-scale length of 0.3-3 um overlaps the claimed average particle diameter range of 0.5-4 um).
MPEP 2144.05 (I) states, “[i]n the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.”
Ishida, Aihara, Imamura, Park and Zhao are considered to be analogous to the claimed invention because they are in the same field of producing and processing silicon containing materials for silicon nitride sintered bodies. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the overlapping average particle diameter range of the metallic silicon powder as taught by Zhao in the silicon powder preparation process of Ishida in view of Aihara, Imamura and Park, since the particle diameter of metallic silicon powder is a recognized result-effective variable affecting the preparation and sintering characteristics of silicon nitride sintered bodies. Such optimization through routine experimentation would have predictably yielded suitable silicon powder for nitriding and sintering processes, in order to ensure that “the resource utilization of the silicon waste is realized through a series of treatment processes, so that the waste of resources is avoided” (Zhao (translation), p. 3, lns. 18-19), thereby utilizing recycled silicon waste materials while minimizing contamination with metal impurities during pulverizing (Zhao (translation), abstract: “a method … characterized in that the content of impurity elements is controlled”).
Regarding claim 18, Ishida in view of Aihara, Imamura, Park and Zhao does not explicitly teach
rare earth element-containing compound powder has an average particle diameter of 0.1 um to 1 um, and magnesium-containing compound powder has an average particle diameter of 0.1 um to 1 um.
However, Yamamoto teaches a silicon nitride sintered body (abstract: “silicon nitride sintered body”) wherein
rare earth element-containing compound powder has an average particle diameter of 0.1 um to 1 um (col. 6, ln. 47-48: “powder of Y2O3 … having mean grain diameter of 0.8 um”), and
magnesium-containing compound powder has an average particle diameter of 0.1 um to 1 um (col. 6, ln. 47-48: “powder of … MgO having mean grain diameters of … 0.5 um”).
Ishida, Aihara, Imamura, Park, Zhao and Yamamoto are considered to be analogous to the claimed invention because they are in the same field of producing and processing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to include the rare earth element-containing compound powder and the magnesium-containing compound powder having the particle size ranges taught by Yamamoto in the metallic silicon powder of Ishida, Aihara, Imamura, Park and Zhao for forming the silicon nitride sintered body, for the purpose of ensuring “the relative density of the sintered body being 98% or more” (Yamamoto, col. 2, lns. 22-23), in order to “stably provide a sintered body having a high strength on an industrial scale without limitation” (Yamamoto, col. 3, lns. 47-49), thereby improving the density and strength properties of the resulting silicon nitride sintered body.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Ishida et al. (JP 2013157570) hereinafter Ishida, in view of Aihara et al. (JP 4648030) hereinafter Aihara, Imamura et al. (US 20190031566) hereinafter Imamura, Park et al. (KR 20110083009) hereinafter Park, and further in view of Yamamoto et al. (US 5204297) hereinafter Yamamoto.
Regarding claim 20, Ishida in view of Aihara, Imamura and Park teaches the electrostatic chuck heater (Ishida: 10) of claim 17, wherein
the rare earth element-containing compound is yttrium oxide, and the magnesium-containing compound is magnesium oxide (Imamura, paragraph [0071]: “Mg compound powder … and … rare earth element compound powder”; paragraph [0070]: “sintering additive is a combination of MgO powder and Y2O3 powder”).
Ishida, Aihara, Imamura and Park does not explicitly teach the mixed raw material powder contains 2 mol% to 5 mol% of yttrium oxide and 2 mol% to 10 mol% of magnesium oxide.
However, Yamamoto teaches a silicon nitride sintered body (abstract: “silicon nitride sintered body”) wherein
mixed raw material powder contains 2 mol% to 5 mol% of yttrium oxide (Table 1 teaches Y2O3 composition ranging between 1.2 and 6.1 % by mole, overlapping the claimed 2-5 mol%) and 2 mol% to 10 mol% of magnesium oxide (Table 1 teaches MgO composition ranging between 1.6 to 10.0 % by mole overlapping the claimed 2-10 mol%).
MPEP 2144.05 (I) states, “[i]n the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists.”
Ishida, Aihara, Imamura, Park and Yamamoto are considered to be analogous to the claimed invention because they are in the same field of producing and processing a silicon nitride sintered body. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to employ the overlapping mol% ranges of yttrium oxide and magnesium oxide taught by Yamamoto in the mixed raw material powder of Ishida in view of Aihara, Imamura and Park, because the additive composition amounts are recognized result-effective variables in preparing silicon nitride sintered bodies. Such optimization through routine experimentation would have predictably yielded “the relative density of the sintered body being 98% or more” (Yamamoto, col. 2, lns. 22-23), in order to “stably provide a sintered body having a high strength on an industrial scale without limitation” (Yamamoto, col. 3, lns. 47-49), thereby improving the density and strength properties of the resulting silicon nitride sintered body.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Minakata et al. (US 20200406586), Kim et al. (US 20200165167), Imai (US 20200064375), Matsumoto et al. (JP 2019052072), Tsutsumi et al. (JP 2018098164), Komatsubara et al. (JP 6235700), Kano (US 20090242544), Nagasaki (JP 3488334), Oyama et al. (US 20010003277), Komatsu (US 6242374), Matsui et al. (US 5352641).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JE HWAN JOHN PARK whose telephone number is (571)272-6405. The examiner can normally be reached Monday-Friday 9AM-5PM.
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, Edward F. Landrum can be reached at 571-272-5567. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/J.J.P./Examiner, Art Unit 3761 /EDWARD F LANDRUM/Supervisory Patent Examiner, Art Unit 3761
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