Prosecution Insights
Last updated: April 19, 2026
Application No. 17/485,617

GaN SUBSTRATE WAFER AND METHOD FOR MANUFACTURING GaN SUBSTRATE WAFER

Final Rejection §103
Filed
Sep 27, 2021
Examiner
HATFIELD, MARSHALL MU-NUO
Art Unit
2897
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Mitsubishi Chemical Corporation
OA Round
4 (Final)
94%
Grant Probability
Favorable
5-6
OA Rounds
3y 5m
To Grant
98%
With Interview

Examiner Intelligence

Grants 94% — above average
94%
Career Allow Rate
64 granted / 68 resolved
+26.1% vs TC avg
Minimal +3% lift
Without
With
+3.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
34 currently pending
Career history
102
Total Applications
across all art units

Statute-Specific Performance

§103
50.6%
+10.6% vs TC avg
§102
33.1%
-6.9% vs TC avg
§112
16.0%
-24.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 68 resolved cases

Office Action

§103
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 . Response to Arguments Applicant's arguments, see page 7, paragraph 6 of applicant’s arguments filed 10/01/2025 in regards to the rejection of claim 1 under 35 U.S.C. 103 over Ishihara(JP 2015214441 A1, hereafter Ishihara) in view of Masahiro et al.(WO 2017026196 A1, hereafter Masahiro) have been fully considered but they are not persuasive. The argument for the impropriety of the rejection appears to be that the two references use a method which are so different in their application(HVPE vs. flux) as to preclude their combination(See paragraph 5, Page 7 of applicant’s arguments). It is acknowledged that there are major differences in the process by which Ishihara’s and Masahiro’s wafers are produced. The argument that combining the methods would be non-obvious could be persuasive in the context of a claimed method. However, claim 1 is in regards to a component of a device, specifically a wafer. The justification for combination of features of the two wafers disclosed by Ishihara and Masahiro respectively is in regards to a wafer, and not a process for producing that wafer. The examiner maintains that one of ordinary skill in the art, in pursuit of addressing known problems such as cracks and dislocations, would look to roughness for a regrowth interface, such as the one disclosed by Masahiro(See Fig. 7 [C]), in order to address these issues. The following issue of the incompatibility of combining the methods disclosed by Ishihara and Masahiro is in regards to a resulting method, and not a GaN wafer. Furthermore, applicant’s argument that Ishihara and Masahiro teach away from each other due to their different heating rates, temperatures, and growth rates(See Applicant’s arguments, Page 10 final paragraph and Page 11 paragraphs 1-2) is not persuasive as the fact the two references give different specification for these parameters does not mean they teach away(See MPEP 2144.05, Sec. III, Par. B). The rejections of claims dependent on claim 1 as well as claim 14, of which the grounds for rejection are the same, are maintained. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Hachigo(US 20110073871 A1) discloses a gallium nitride substrate with a dopant concentration of a range of values. Fujita(US 8409350 B2) discloses a gallium nitride crystal growth method with a silicon dopant gas. Brown et al.(US 20190027644 A1) discloses a GaN substrate with varying emitted light wavelengths for use in light emitting diodes. THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARSHALL MU-NUO HATFIELD whose telephone number is (703)756-1506. The examiner can normally be reached Mon-Thus 11:00 AM-9:00PM EST. 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, Fernando Toledo can be reached on 571-272-1867. 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. /MARSHALL MU-NUO HATFIELD/Examiner, Art Unit 2897 /FERNANDO L TOLEDO/Supervisory Patent Examiner, Art Unit 2897
Read full office action

Prosecution Timeline

Sep 27, 2021
Application Filed
Apr 25, 2024
Non-Final Rejection — §103
Jul 30, 2024
Response Filed
Sep 30, 2024
Final Rejection — §103
Feb 28, 2025
Request for Continued Examination
Mar 04, 2025
Response after Non-Final Action
May 28, 2025
Non-Final Rejection — §103
Oct 01, 2025
Response Filed
Oct 01, 2025
Response after Non-Final Action
Dec 03, 2025
Final Rejection — §103 (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
94%
Grant Probability
98%
With Interview (+3.4%)
3y 5m
Median Time to Grant
High
PTA Risk
Based on 68 resolved cases by this examiner. Grant probability derived from career allow rate.

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