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 1-18 are, drawn to a method, classified in C30B 25/02.
II. Claim 19, drawn to a product, classified in H10P 14/3208.
The inventions are independent or distinct, each from the other because:
Inventions I and II are related as process of making and product made. The inventions are distinct if either or both of the following can be shown: (1) that the process as claimed can be used to make another and materially different product or (2) that the product as claimed can be made by another and materially different process (MPEP § 806.05(f)). In the instant case the process as claimed can be used to make another and materially different product, such as a substrate having a number of crystallographic defects of 1 ppm or more.
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 Gary Fedorochko on 05/11/2026 a provisional election was made without traverse to prosecute the invention of Group I, claims 1-18. Affirmation of this election must be made by applicant in replying to this Office action. Claim 19 is withdrawn from further consideration by the examiner, 37 CFR 1.142(b), as being drawn to a non-elected invention.
Claim Objections
Claim 17 is objected to because of the following informalities: Claim 17 recites “is carrier out continuously or discontinuously”. It appears “carrier” is a typo and should be “carried.” Appropriate correction is required.
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.
Claims 1-18 are 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 1 recites, “a process for producing silicon carbide (SiC) substrates” in the line, however the remaining claim limitations does not recite any steps for producing SiC. Claim 1 merely recites for a first buffer layer, a first epitaxial layer, a second buffer layer and a second epitaxial layer, however it is unclear if any of the layers are SiC. Furthermore, dependent claim 2 recites “first, second, third and fourth process gases comprise a gas selected from: SiHCl3, SiH4, Si2H6, H2SiCl2, Teos (tetraethyl orthosilicate)” which does not include any source of carbon for forming SiC. The same argument applies to dependent claims 2-18.
Claims 1-18 are 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 1 recites “1) growing a first buffer layer (B1) on a substrate (S) using a first process gas comprising a first concentration of doping agent, 2) growing a first epitaxial layer (epi1) above said first buffer layer (B1) using a second process gas comprising a second concentration of doping agent, 3) growing a second buffer layer (B2) above said first epitaxial layer (epi1) using a third process gas comprising a third concentration of doping agent, 4) growing a second epitaxial layer (epi2) above said second buffer layer (B2) using a fourth process gas comprising a fourth concentration of doping agent.” It is unclear how to grow the first buffer, first epitaxial, second buffer and second epitaxial layer having a dopant concentration when the first, second, third and fourth process gases comprise a gas selected from: SiHCl3, SiH4, Si2H6, H2SiCl2, Teos (tetraethyl orthosilicate) (See dependent claim 2). For the purposes of expediating examination, claim 1 is interpreted as including a dopant concentration of 0. The same argument applies to dependent claims 2-18.
Claim 15 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 15 recites “in steps 1) and 3) a carbon/silicon ratio up to 3.” It is unclear how to achieve a carbon/silicon ratio when claim 1 recites a “process gas” rather than a gas mixture. There is no carbon gas source or silicon gas source recited, and no gas mixture; therefore, it is unclear what the carbon/silicon ratio refers to.
Claim 16 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 16 recites “in steps 2) and 4) a carbon/silicon ratio up to 2.” It is unclear how to achieve a carbon/silicon ratio when claim 1 recites a “process gas” rather than a gas mixture. There is no carbon gas source or silicon gas source recited, and no gas mixture; therefore, it is unclear what the carbon/silicon ratio refers to.
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(s) 1-3, 11 and 13-18 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Li (EP 3547349 A1).
Li teaches 1) growing a first buffer layer (B1) on a substrate (S) using a first process gas comprising a first concentration of doping agent (low doping concentration Buffer layer 1), 2) growing a first epitaxial layer (epi1) above the first buffer layer (B1) using a second process gas comprising a second concentration of doping agent (high doping concentration Buffer layer 2), 3) growing a second buffer layer (B2) above the first epitaxial layer (epi1) using a third process gas comprising a third concentration of doping agent (second cycle of low doping concentration Buffer layer 1), 4) growing a second epitaxial layer (epi2) above the second buffer layer (B2) using a fourth process gas comprising a fourth concentration of doping agent (second cycle of high doping concentration Buffer layer 2). (abstract and [0009]-[0016] teaches epitaxially growing a high-low doping concentration composite buffer using a silicon source, carbon source and n-type or p-type dopant, wherein the buffer layer 1 has a doping concentration of 2 to 5E18 cm-3 and buffer layer 2 has a doping concentration of 5 to 8E18cm-3; and explicit examples of two cycles of highly-lightly doped structures).
Referring to claim 2, Li teaches silane, dichloro hydrogen silicon, trichlorosilane, tetrachloro hydrogen silicon; and explicit examples of using SiH4 ([0010]-[0015]).
Referring to claim 3, Li teaches silane, dichloro hydrogen silicon, trichlorosilane, tetrachloro hydrogen silicon; and explicit examples of using SiH4 ([0010]-[0015]), and silane is an alkane.
Referring to claim 11, Li teaches an explicit example with dopant concentration of 2E18 cm-3 and 5E17 cm-3 ([0015]), which is within the claimed range of up to 1%.
Referring to claim 13-14, Li teaches an explicit example of growth of buffer layer 1 to a thickness of 0.5 mm with a growth time of 6 min and buffer layer 2 to a thickness of 0.5 mm with a growth time of 6 min ([0015] 0.5/(6/60)=5 mm/h.
Referring to claim 15-16, Li teaches an explicit example of a C/Si ratio of 0.9 and 1.2 ([0015]).
Referring to claim 17, Li teaches a process which is either continuous or discontinuous because claim limitation encompasses all possibilities.
Referring to claim 18, Li teaches a second epitaxial layer thickness of 0.5 mm ([0015]).
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.
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li (EP 3547349 A1), as applied to claims 1-3, 11 and 13-18 above.
Li teaches all of the limitations of claim 12, as discussed above, except Li does explicitly teach the first and third concentrations are higher than each of the second and fourth concentration of doping agent.
Li teaches a high-low doping concentration epitaxial buffer layer (abstract) and repeating the steps a number of times ([0010]). It would have been obvious to one of ordinary skill in the art at the time of filing to modify Li by repeating the high-low steps at least 3 times to reduce defects [0016], which would meet the claimed limitation because the first high concentration layer formed reads on the first concentration; then a low concentration layer reads on a second concentration; then a high concentration layer and then a low concentration layer is formed.
Claim(s) 4-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Li (EP 3547349 A1), as applied to claims 1-3, 11 and 13-18 above, and further in view of Li et al (US 2023/0118623).
Li teaches all of the limitations of claim 4, as discussed above, except Li does not teach the flow rates of the process gases is 10-25 sccm.
In a method of making SiC, Li et al teaches a number of silicon carbide films 210 in a buffer layer 200; the silicon carbide film 210 may be formed by a chemical vapor deposition (CVD) process by introducing a carbon-source gas and a silicon-source gas into a process chamber; the carbon-source gas may include at least one of methane, ethylene, acetylene and propane; the silicon-source gas may include at least one of dichlorosilane, trichlorosilane and tetrachlorosilane; the carbon-source gas is introduced, for example, at a flow rate of 10 sccm to 200 sccm; the silicon-source gas is introduced, for example, at a flow rate of 10 sccm to 100 sccm; during the introduction of the carbon-source gas and the silicon-source gas, a hydrogen-source gas may be introduced to modify silicon carbide that has been grown to improve quality of the resulting silicon carbide film 210, wherein, the hydrogen-source gas may include hydrogen and/or hydrogen chloride; and hydrogen maybe introduced at a flow rate of 10 sccm to 200 sccm (Fig 1; [0023]-[0039]). Overlapping ranges are prima facie obvious (MPEP 2144.05).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Li by optimizing the flow rates of the process gas within the conventionally known range taught by Li et al, to obtain the claimed range by conducting routine experimentation of a result effective variable, to improve the quality of SiC.
Referring to claim 5-10, the combination of Li and Li et al teaches ; the silicon-source gas may include at least one of dichlorosilane, trichlorosilane and tetrachlorosilane; the carbon-source gas is introduced, for example, at a flow rate of 10 sccm to 200 sccm; the silicon-source gas is introduced, for example, at a flow rate of 10 sccm to 100 sccm; during the introduction of the carbon-source gas and the silicon-source gas, a hydrogen-source gas may be introduced to modify silicon carbide that has been grown to improve quality of the resulting silicon carbide film 210, wherein, the hydrogen-source gas may include hydrogen and/or hydrogen chloride; and hydrogen maybe introduced at a flow rate of 10 sccm to 200 sccm (Li et al [0035]-[0039]). Overlapping ranges are prima facie obvious (MPEP 2144.05).
Conclusion
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.
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, 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.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
MATTHEW J. SONG
Examiner
Art Unit 1714
/MATTHEW J SONG/ Primary Examiner, Art Unit 1714
