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 .
Election/Restrictions
Restriction to one of the following inventions is required under 35 U.S.C. 121:
I. Claims 1-10, drawn to a method, classified in C30B 33/02.
II. Claims 11-18, drawn to an apparatus, classified in F27B 17/0016.
The inventions are independent or distinct, each from the other because:
Inventions I and II are related as process and apparatus for its practice. The inventions are distinct if it can be shown that either: (1) the process as claimed can be practiced by another and materially different apparatus or by hand, or (2) the apparatus as claimed can be used to practice another and materially different process. (MPEP § 806.05(e)). In this case the apparatus as claimed can be used to practice another and materially different process, such as heat treatment of another material other than SiC, such as a silicon crystal.
Restriction for examination purposes as indicated is proper because all the inventions listed in this action are independent or distinct for the reasons given above and there would be a serious search and/or examination burden if restriction were not required because one or more of the following reasons apply:
--the inventions require a different field of search (e.g., searching different
classes/subclasses or electronic resources, or employing different search strategies or search queries).
Applicant is advised that the reply to this requirement to be complete must include (i) an election of an invention to be examined even though the requirement may be traversed (37 CFR 1.143) and (ii) identification of the claims encompassing the elected invention.
The election of an invention may be made with or without traverse. To reserve a right to petition, the election must be made with traverse. If the reply does not distinctly and specifically point out supposed errors in the restriction requirement, the election shall be treated as an election without traverse. Traversal must be presented at the time of election in order to be considered timely. Failure to timely traverse the requirement will result in the loss of right to petition under 37 CFR 1.144. If claims are added after the election, applicant must indicate which of these claims are readable upon the elected invention.
Should applicant traverse on the ground that the inventions are not patentably distinct, applicant should submit evidence or identify such evidence now of record showing the inventions to be obvious variants or clearly admit on the record that this is the case. In either instance, if the examiner finds one of the inventions unpatentable over the prior art, the evidence or admission may be used in a rejection under 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a) of the other invention.
During a telephone conversation with Laurence Greenberg on 05/19/2026 a provisional election was made without traverse to prosecute the invention of Group I, claims 1-10. Affirmation of this election must be made by applicant in replying to this Office action. Claims 1-10 are withdrawn from further consideration by the examiner, 37 CFR 1.142(b), as being drawn to a non-elected invention.
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
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.
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) 1-2 and 6-7 is/are rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Chen et al (CN 113564719A), an English computer translation (CT) is provided.
Chen et al teaches a method for the thermal post-treatment of at least one silicon carbide (SiC) volume monocrystal which has a substantially cylindrical basic shape with a crystal length measured in an axial direction, with a crystal diameter measured in a radial direction, with a crystal central longitudinal axis extending in the axial direction, and with three boundary surfaces, namely, a bottom surface, a top surface, and a circumferential edge surface (Fig 1 shows SiC crystal 7 with three boundary surfaces; CT [n0040] teaches a crystal diameter of 4 to 8 inches, a thickness of 10 to 60 mm) and, the method comprising the following steps: a) bringing the SiC volume monocrystal to a post-treatment temperature to reduce mechanical stresses present in the SiC volume monocrystal after completion of a previous growth (CT n[0028] teaches secondary annealing and keeping radial temperature gradients between 2 and 6°C, so that internal stresses can be released), and thereby b) setting an inhomogeneous temperature profile in the SiC volume monocrystal with a radial thermal gradient (CT [n0028] teaches a radial and axial temperature gradient between 2 and 6°C so that internal stresses can be released slowly); and c) effecting a heat exchange of the SiC volume monocrystal with a free space surrounding the SiC volume monocrystal by way of free heat radiation on at least two of the three boundary surfaces (Fig 1 shows crystal 7 supported by graphite ring 8 so that a free space surrounding the SiC volume monocrystal on all three exposed boundary surfaces which reads on free heat radiation on at least two of the three boundary surfaces).
Chen et al teaches an annealing process with a crystal having free space on all three boundary surface (Fig 1), and setting an inhomogeneous radial temperature gradient between 2 and 6°C ([n0032]). Chen et al does not explicitly teach a radial thermal gradient, which increases continuously from the crystal central longitudinal axis to the circumferential edge surface. Chen et al teaches substantially the same method of heating a crystal on at least two exposed boundary surfaces to produce a radial temperature gradient, as applicant, therefore, the same effect of a radial thermal gradient, which increases continuously from the crystal central longitudinal axis to the circumferential edge surface. Also, the heater 2 is adjacent the peripheral boundary surface of the crystal 7; therefore, a radial thermal gradient, which increases continuously from the crystal central longitudinal axis to the circumferential edge surface would be inherent. In the alternative, any differences would have been minor and would have been obvious to one of ordinary skill in the art at the time of filing.
Referring to claim 2, Chen et al teaches the crystal 7 is surround by free space on all three boundary surface (Fig 1).
Referring to claim 6-7, Chen et al teaches Ar gas (CT [n0100]-[n0104]).
Claim(s) 3 and 8-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al (CN 113564719A), an English computer translation (CT) is provided, as applied to claims 1-2 above.
Chen et al teaches all of the limitations of claim 3, as discussed above, except the total surface area is composed of a sum of the three boundary surfaces and the radiant surface portion lies in a range from 63% to 83% of the total surface area.
Chen et al teaches 4-8 inch (~100-200 mm) diameter SiC crystal 7, 10-60 mm thickness (CT [n0040]), and an annular graphite felt support 8 is preferably 1/3 to 2/3 of the diameter of the silicon carbide crystal (CT [n0061]). The total surface area of a cylinder can be determined by the formula total surface=2pr(r+h), r is radius and h is height; and a portion of the upper surface and lower surface of the cylinder would be covered by the graphite felt which is 1/3 to 2/3 of the diameter; therefore, an exposed radiant surface portion lies in a range from 63% to 83% of the total surface area would have been obvious to one of ordinary skill in the art at the time of filing by modifying Chen et al, to have a graphite felt and crystal having dimensions within the ranges taught by Chen et al. Changes in size and shape are prima facie obvious (MPEP 2144.05). For example, a 150 mm diameter (radius 75 mm), 50 mm thick and an annular felt with 1/3 of the inner radius (50 mm radius exposed), would have a TSA=2pr(r+h) TSA=2x3.14x75x(75+50)=58875 mm2. The lateral surface area of a cylinder is LSA=2prh, so LSA=2*3.14x75x50=23550. The top surface area of a circle is area=pr2, thus area with the felt cover 1/3 of radius for the exposed top and bottom surface area would be 2x(pr2)=15701.57 mm2. The later surface area, the top exposed and bottom exposed surface area would be 39251.57 mm2. 39251.57/58875=66.669%.
Referring to claim 8-9, Chen et al teaches 4-8 inch (~100-200 mm) diameter SiC crystal 7, 10-60 mm thickness (CT [n0040]). Overlapping ranges are prima facie obvious (MPEP 2144.05). Furthermore, changes in size and shape are prima facie obvious (MPEP 2144.04).
Referring to claim 10, Chen et al teaches 4-8 inch (~100-200 mm) diameter SiC crystal 7, 10-60 mm thickness (CT [n0040]), which would produce a crystal have the claimed aspect ratio. Overlapping ranges are prima facie obvious (MPEP 2144.05). Furthermore, changes in size and shape are prima facie obvious (MPEP 2144.04).
Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al (CN 113564719A), an English computer translation (CT) is provided, as applied to claims 1-3 and 6-10 above, and further in view of Noguchi (US 2024/0200227).
Chen et al teaches all of the limitations of claim 4, as discussed above, except the radial thermal gradient is between 0.1 K/cm to 0.3 K/cm in a central region to half of the crystal diameter. Chen et al teaches a radial temperature gradient of 2-6°C, however does not explicitly teach 0.1 K/cm to 0.3 K/cm in a central region to half of the crystal diameter.
In a method of annealing SiC, Noguchi teaches after a SiC ingot 27 is produced, the SiC ingot 27 is annealed, and the annealing is performed so that the maximum temperature is 1,500°C or higher, and annealing is performed by creating a temperature gradient of the SiC ingot 27 in the radial direction, wherein the temperature gradient of the SiC ingot 27 in the radial direction on the offset-upstream side is made to be less than 0.7° C/cm so a wafer is less likely to warp ([0067]-[0070]).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Chen et al by optimizing the radial temperature gradient to be less than 0.7 C/cm, as taught by Noguchi, to prevent warping. Overlapping ranges are prima facie obvious (MPEP 2144.05).
Referring to claim 5, the combination of Chen et al and Noguchi teaches radial temperature gradient to be less than 0.7 C/cm. Overlapping ranges are prima facie obvious (MPEP 2144.05).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2013/0269598 teaches an in-situ annealing of a SiC crystal comprising a temperature gradient of less than 5°C/cm ([0008]-[0030], claim 15-16).
US 2023/0392285 teaches a heating means and the heat-insulating member 30 are adjusted so that the temperature gradient of the SiC single crystal ingot in the radial direction is 20° C/cm or less and the temperature gradient of the SiC single crystal ingot in the growth direction is in the range of 0°C/cm to 50° C/cm, and the ingot is annealed at 1800°C to 2000° C for 10 hours to 20 hours ([0139]).
US 2023/0243064 teaches based on a defined spatial arrangement of the thermal insulation surrounding the crucible which consists of several zones with different insulation properties, i.e. of different thermal conductivity; and the radial temperature gradient can thereby be reduced to a value less than or equal to 0.1 K/cm ([0014]).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MATTHEW J SONG whose telephone number is (571)272-1468. The examiner can normally be reached Monday-Friday 10AM-6PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kaj Olsen can be reached at 571-272-1344. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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MATTHEW J. SONG
Examiner
Art Unit 1714
/MATTHEW J SONG/ Primary Examiner, Art Unit 1714
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