Prosecution Insights
Last updated: April 19, 2026
Application No. 17/879,118

SiC EPITAXIAL WAFER AND METHOD FOR MANUFACTURING SiC EPITAXIAL WAFER

Non-Final OA §103§DP
Filed
Aug 02, 2022
Examiner
CHEN, JACK S J
Art Unit
2893
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Renosac Corporation
OA Round
5 (Non-Final)
76%
Grant Probability
Favorable
5-6
OA Rounds
2y 10m
To Grant
82%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
432 granted / 565 resolved
+8.5% vs TC avg
Moderate +6% lift
Without
With
+5.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 10m
Avg Prosecution
33 currently pending
Career history
598
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
30.0%
-10.0% vs TC avg
§102
34.2%
-5.8% vs TC avg
§112
26.3%
-13.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 565 resolved cases

Office Action

§103 §DP
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 . The Finality of the rejection of the last Office action 4/3/2025 is hereby withdrawn in view of the notice of panel decision from pre-appeal brief review. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-3, 10-14, 16-21 and 23-26 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-9 of U.S. Patent No. 12,546,030 B2. Although the claims at issue are not identical, they are not patentably distinct from each other because the instant claims are within the scope of the cited prior art’s claims. Claim Rejections - 35 USC § 103 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. Claims 1-3, 10-14, 16-21 and 23-26 are rejected under 35 U.S.C. 103 as being unpatentable over ETO et al. US Pub. No. 2019/0252504 A1. Re claims 1 and 17, ETO et al. disclose a SiC wafer, comprising: a SiC substrate (i.e., paragraphs 27, 36, 32 the substrate (i.e., n-type SiC single crystal, paragraph 27 Note: the lower portion/part of the n-type SiC single crystal substrate is considered as the SiC substrate) is comprising of a plurality of the sub-layers (i.e., lower and upper parts/portions) of the same material (i.e., regarding how it is formed, SiC doped with both donor (i.e., n-type, paragraph 71) and acceptor (i.e., boron, paragraph 71); the bottom/lower sub-layer/part/protion is considered as the SiC substrate; and an upper portion/part/sublayer of the n-type SiC single crystal is considered as the phrase “an epitaxial layer of SiC laminated on the SiC substrate” (the phrase “an epitaxial layer” of the instant claim is considered as an upper part/portion/sublayer of the n-type SiC single crystal substrate since the lower and upper part/portion are formed from the same material, SiC single crystal, having the same crystal structure and orientation and the epitaxial/upper portion/part/layer laminated on the SiC substrate, i.e., lower part/portion/layer of the SiC substrate); wherein the epitaxial layer (an upper portion/part/sublayer of the n-type SiC single crystal) contains an n-type impurity element (i.e., Nitrogen, paragraph 61, 71) and boron (i.e., paragraph 61, 71) and the concentration of boron in the center (paragraph 69), see figs. 1-6 and pages 1-9 for more details. Note: Epitaxy is a crystal growth technique/process to produce a layer having some inherently characteristics, i.e., the same crystal structure/orientation as the base layer. Re claims 1 and 17, the phrase “an epitaxial layer of SiC laminated on the SiC substrate” and/or “epitaxial” and/or “is measured by secondary ion mass spectrometry” the process limitation of how the film is formed and/or how the concentration is measured has no patentable weight in claim drawn to structure. Note that a product by process claim is directed to the product per se, no matter how actually made, In re Hirao, 190 USPQ 15 at 17 (footnote 3). See also In re Brown, 173 USPQ 685; In re Luck, 177 USPQ 523; In re Fessmann, 180 USPQ 324; In re Avery, 186 USPQ 161; In re Wertheim, 191 USPQ 90 (209 USPQ 554 does not deal with this issue); and In re Marosi et al, 218 USPQ 289, all of which make it clear that it is the patentability of the final product per se which must be determined in a product by process claim, and not the patentability of the process, and that an old or obvious product by a new method is not patentable as a product, whether claimed in product by process claims or not. Note that applicant has the burden of proof in such cases, as the above caselaw makes clear. Therefore, the above recited phrase is thus non-limiting. Although the exact recitations “a concentration of boron in the center of a main face of the epitaxial layer in plan view is 2.0 x 1012cm-3 or less” or “a concentration of boron in the center of a main face of the epitaxial layer in plan view, which is measured by secondary ion mass spectrometry, is 5.0 x 1012cm-3 or less” or “2.0 x 1012cm-3 or less” is not explicitly stated by ETO et al. in the related text; however, paragraph 67 of the cited prior art states “donor concentration and acceptor concentration in the central portion can be arbitrarily selected” therefore, the instant claim appear to be Prima Facie obvious over ETO et al. Therefore, one of ordinary skill in the requisite art before the invention was made would have used any acceptor (i.e., boron) concentration range (i.e., see paragraph 67) suitable to device of ETO et al. in order to optimize the device performance etc. Furthermore, the specification contains no disclosure of either the critical nature of the claimed arrangement (i.e. - a concentration of boron in the center of a main face of the epitaxial layer in plan view is 2.0 x 1012cm-3 or less or “a concentration of boron in the center of a main face of the epitaxial layer in plan view, which is measured by secondary ion mass spectrometry, is 5.0 x 1012cm-3 or less”) or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen limitations or upon another variable recited in a claim, the Applicant must show that the chosen limitations are critical. In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990). Re claim 10, The SiC epitaxial wafer according to claim 1, wherein a concentration of the n-type impurity element is 1.0x1014cm3 or more and 3.0x1016cm-3 or less (i.e., see paragraph 136). Re claim 25, The SiC epitaxial wafer according to claim 17, wherein a concentration of the n-type impurity element is 1.0x1014cm3 or more and 3.0x1016cm-3 or less (i.e., see paragraph 136). Re claim 11, The SiC epitaxial wafer according to claim 1, wherein the n-type impurity element is nitrogen (i.e., Nitrogen, paragraph 61). Re claim 26, The SiC epitaxial wafer according to claim 17, wherein the n-type impurity element is nitrogen (i.e., Nitrogen, paragraph 61). The wafer size range of claims 2-3, 23-24 and the concentration range of claims 1,10,16, 17, 18 and 25 are considered to involve routine optimization while has been held to be within the level of ordinary skill in the art. As noted in In re Aller, the selection of reaction parameters such as temperature and concentration etc. would have been obvious: “Normally, it is to be expected that a change in temperature, or in concentration, or in both, would be an unpatentable modification. Under some circumstances, however, changes such as these may impart patentability to a process if the particular ranges claimed produce a new and unexpected result which is different in kind and not merely degree from the results of the prior art...such ranges are termed Acritical ranges and the applicant has the burden of proving such criticality.... More particularly, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller 105 USPQ233, 255 (CCPA 1955). See also In re Waite 77 USPQ 586 (CCPA 1948); In re Scherl 70 USPQ 204 (CCPA 1946); In re Irmscher 66 USPQ 314 (CCPA 1945); In re Norman 66 USPQ 308 (CCPA 1945); In re Swenson 56 USPQ 372 (CCPA 1942); In re Sola 25 USPQ 433 (CCPA 1935); In re Dreyfus 24 USPQ 52 (CCPA 1934). Therefore, one of ordinary skill in the requisite art before the invention was made would have used any wafer size range and the concentration range suitable to device of ETO et al. in order to optimize the device performance etc. Re claims 12 and 19, wherein the epitaxial layer (i.e., upper portion/part of the substrate) serves as an active region. Furthermore, a recitation of the intended use and/or function of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use and/or function, then it meets the claim. Re claims 13-14 and 20-21, the phrase “is obtained by processing a bulk single crystal of SiC” and/or “is obtained by slicing a single crystal ingot of SiC” the process limitation of how the film is formed and/or how the concentration is measured has no patentable weight in claim drawn to structure. Note that a product by process claim is directed to the product per se, no matter how actually made, In re Hirao, 190 USPQ 15 at 17 (footnote 3). See also In re Brown, 173 USPQ 685; In re Luck, 177 USPQ 523; In re Fessmann, 180 USPQ 324; In re Avery, 186 USPQ 161; In re Wertheim, 191 USPQ 90 (209 USPQ 554 does not deal with this issue); and In re Marosi et al, 218 USPQ 289, all of which make it clear that it is the patentability of the final product per se which must be determined in a product by process claim, and not the patentability of the process, and that an old or obvious product by a new method is not patentable as a product, whether claimed in product by process claims or not. Note that applicant has the burden of proof in such cases, as the above caselaw makes clear. Therefore, the above recited phrase is thus non-limiting. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JACK CHEN whose telephone number is (571)272-1689. The examiner can normally be reached Monday to Friday, 8am to 4pm. 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, Yara J. Green can be reached at (571)270-3035. 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. /JACK S CHEN/ Primary Examiner, Art Unit 2893
Read full office action

Prosecution Timeline

Aug 02, 2022
Application Filed
Feb 02, 2023
Response after Non-Final Action
Jun 14, 2023
Non-Final Rejection — §103, §DP
Sep 14, 2023
Applicant Interview (Telephonic)
Sep 14, 2023
Examiner Interview Summary
Sep 20, 2023
Response Filed
Oct 19, 2023
Final Rejection — §103, §DP
Jan 31, 2024
Applicant Interview (Telephonic)
Jan 31, 2024
Examiner Interview Summary
Mar 14, 2024
Examiner Interview Summary
Mar 14, 2024
Applicant Interview (Telephonic)
Apr 24, 2024
Response after Non-Final Action
Apr 24, 2024
Notice of Allowance
May 29, 2024
Response after Non-Final Action
Aug 25, 2024
Non-Final Rejection — §103, §DP
Feb 28, 2025
Response Filed
Mar 30, 2025
Final Rejection — §103, §DP
Sep 15, 2025
Response after Non-Final Action
Oct 03, 2025
Notice of Allowance
Oct 03, 2025
Response after Non-Final Action
Nov 12, 2025
Response after Non-Final Action
Nov 12, 2025
Response after Non-Final Action
Mar 20, 2026
Non-Final Rejection — §103, §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
76%
Grant Probability
82%
With Interview (+5.9%)
2y 10m
Median Time to Grant
High
PTA Risk
Based on 565 resolved cases by this examiner. Grant probability derived from career allow rate.

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