Prosecution Insights
Last updated: April 19, 2026
Application No. 17/924,248

METHOD FOR ETCHING SILICON WAFER

Non-Final OA §112
Filed
Nov 09, 2022
Examiner
PHAM, THOMAS T
Art Unit
1713
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Shin-Etsu Handotai Co. Ltd.
OA Round
3 (Non-Final)
52%
Grant Probability
Moderate
3-4
OA Rounds
3y 3m
To Grant
67%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
292 granted / 565 resolved
-13.3% vs TC avg
Strong +15% interview lift
Without
With
+15.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
69 currently pending
Career history
634
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
49.1%
+9.1% vs TC avg
§102
17.6%
-22.4% vs TC avg
§112
30.3%
-9.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 565 resolved cases

Office Action

§112
DETAILED ACTION This is the Office action based on the 17924248 application filed November 09, 2022, and in response to applicant’s argument/remark filed on October 6, 2025. Claims 6-22 are currently pending and have been considered below. Applicant’s cancellation of claims 1-5 acknowledged. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a):(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. Claim 6 rejected under 35 U.S.C. 112(a) as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor(s), at the time the application was filed, had possession of the claimed invention. Examiner is unable to find support for the negative limitation “after the impinging jet area is covered with the acid mixture, the rotation of the silicon wafer is started without supplying the acid mixture to perform the spin etching steр while the acid etching solution is being supplied” in the specification. It is noted that the specification discloses in paragraph ([0028]) that “Note that, as will be described later, the acid mixture 10 and the acid etching solution 8 can be the same chemical solution”. Applicant argues that the support is provided in paragraphs [0037], [0038] and [0043]. These paragraphs are copied and shown below:“[0037] Next, the spin etching step is performed. Within a period of 1 second or more and 2 seconds or less after the acid mixture is added dropwise within the impinging jet area 20, the rotation of the silicon wafer is preferably started to start the spin etching step of performing the acid etching. When a time of 1 second or more elapses before the rotation of the silicon wafer is started, this enables sufficient generation of nitrite ions autocatalytically generated from nitrogen oxide. When the time is 2 seconds or less, the productivity is not impaired, and it is possible to more effectively prevent surface roughness due to excessive reaction 12 between the silicon and the acid mixture, and the like.”“[0038] Next, an example of the spin etching step will be described in detail. When a predetermined number of rotations reaches after the rotation of the silicon wafer is started, the acid etching solution 8 is supplied from the etching-solution tank 6 to the supply nozzle 3 located above the vacuum sucking stage 2. The acid etching solution 8 is supplied onto the silicon wafer 1 being held and rotated on the vacuum sucking stage 2. As the silicon wafer 1 rotates, the acid etching solution 8 supplied on the silicon wafer 1 is moved on the silicon wafer 1 and discharged from the top of the wafer in the form of droplets 11 via an outer periphery of the silicon wafer 1. When the etching processing is ended after a predetermined etching margin is filled, the supply of the acid etching solution 8 from the etching-solution tank 6 is stopped, and the water 9 is supplied from the water supply source 7 to the supply nozzle 3. The water 9 is supplied onto the silicon wafer 1 being held and rotated on the vacuum sucking stage 2. As the silicon wafer 1 rotates, the water 9 supplied on the silicon wafer 1 is moved on the silicon wafer 1 and discharged as the droplets 11 from the outer periphery of the silicon wafer 1 while the acid etching solution 8 left on the silicon wafer 1 is replaced with the water 9. After the replacement of the acid etching solution 8 with water on the silicon wafer 1 is ended, the supply of the water 9 from the water supply source 7 is stopped, and the silicon wafer 1 is rotated at high speed to scatter all the water on the silicon wafer 1, so that dried silicon wafer 1 is obtained.“[0043] (Example) A silicon wafer was etched using a spin etching apparatus. The acid etching solution used was a mixture solution of hydrofluoric acid and nitric acid, and the mixing ratio in terms of mass% was such that hydrofluoric acid was 10% and nitric acid was 51%. This acid etching solution was also used as the acid mixture which was added dropwise within the impinging jet area. Note that the inner diameter of the supply nozzle was 25 mm. On the vacuum sucking stage in the etching apparatus, a PW having a diameter of 300 mm was placed as the silicon wafer and held by vacuum sucking. Before the rotation of the silicon wafer was started, 30 mL of the acid etching solution was added dropwise from supply nozzle, so that a region having a diameter of 30 mm immediately below the supply nozzle was covered with the acid etching solution. Two seconds after the addition dropwise, the rotation of the silicon wafer was started. When a predetermined number of rotations reached, the acid etching solution was supplied to perform spin etching, and the supply was switched to pure water to remove the acid etching solution. Further, supplying any chemical solution was stopped, and the silicon wafer was dried. The etching was performed such that the etching amount was 10 µm on average.” (all emphases added). For a better understanding, Fig. 2 is also copied and shown below PNG media_image1.png 524 710 media_image1.png Greyscale One of skill in the art would interpret paragraph [0037] as the rotation is started 1-2 seconds after the acid mixture is added dropwise within the impinging jet area 20. The phrase “after the acid mixture is added” would be interpreted as the time period after when the acid mixture is added, which is the time period after the start of the adding of the acid mixture. Paragraph [0037] does not disclose stopping of the adding dropwise of the acid mixture, or the claimed feature “the rotation of the silicon wafer is started without supplying the acid mixture”. One of skill in the art would interpret paragraph [0038] as when the silicon wafer is rotated reaches a predetermined number of turns, the acid etching solution 8 is supplied onto the silicon wafer, moves across the wafer and flows over the edge. After it is determined that the etching is ended, the flow of acid etching solution 8 is stopped. It is noted that the acid etching solution 8 is not the claimed “acid mixture” that is added dropwise. Again, paragraph [0038] does not disclose a stopping of the adding dropwise of the acid mixture, or the claimed feature “the rotation of the silicon wafer is started without supplying the acid mixture”. One of skill in the art would interpret paragraph [0043] as before the rotation of the silicon wafer was started, 30 mL of the acid etching solution was added dropwise from supply nozzle, and two seconds after the addition dropwise, the rotation of the silicon wafer was started, and the paragraph does not exclude additional addition of the acid etching solution subsequent to the adding 30 mL of the acid etching solution. In fact, the same paragraph teaches that “(w)hen a predetermined number of rotations reached, the acid etching solution was supplied to perform spin etching”. Again, paragraph [0043] does not disclose a stopping of the adding dropwise of the acid mixture, or the claimed feature “the rotation of the silicon wafer is started without supplying the acid mixture”. It is well established that “[T]he PTO must give claims their broadest reasonable construction consistent with the specification. . . . Therefore, we look to the specification to see if it provides a definition for claim terms, but otherwise apply a broad interpretation.” In re ICON Health & Fitness, Inc., 496 F.3d 1374, 1379 (Fed. Cir. 2007). “[A]s applicants may amend claims to narrow their scope, a broad construction during prosecution creates no unfairness to the applicant or patentee.” Id. Claims 7-22 rejected under 35 U.S.C. 112(a) because they are directly or indirectly dependent on claim 6. 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. Claim 6 rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Claim 6 recites “after the impinging jet area is covered with the acid mixture, the rotation of the silicon wafer is started without supplying the acid mixture to perform the spin etching steр while the acid etching solution is being supplied”. Since the specification discloses in paragraph ([0028]) that “Note that, as will be described later, the acid mixture 10 and the acid etching solution 8 can be the same chemical solution”, one of skill in the art would not be clear how to both supplying the acid etching solution and not supplying the acid mixture when the acid etching solution is the same as the acid mixture. Claims 7-21 rejected under 35 U.S.C. 112(b) because they are directly or indirectly dependent on claim 6. Response to Arguments Applicant's arguments filed October 6, 2025 have been fully considered as follows:--Regarding Applicant’s argument that the previously cited prior arts do not teach the amended feature “after the impinging jet area is covered with the acid mixture, the rotation of the silicon wafer is started without supplying the acid mixture to perform the spin etching steр while the acid etching solution is being supplied”, this arguments is persuasive. Previous rejection based on Suzuki modified by Rohner and Zi is withdrawn. However, the amendment does not have support in the specification under 35 USC 112(a), and is indefinite under 35 USC 112(b), as explained above. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to THOMAS PHAM whose telephone number is (571) 270-7670 and fax number is (571) 270-8670. The examiner can normally be reached on MTWThF9to6 PST. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Allen can be reached on (571) 270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /THOMAS T PHAM/Primary Examiner, Art Unit 1713
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Prosecution Timeline

Nov 09, 2022
Application Filed
Jan 24, 2025
Non-Final Rejection — §112
Apr 15, 2025
Response Filed
Jul 08, 2025
Final Rejection — §112
Oct 06, 2025
Request for Continued Examination
Oct 09, 2025
Response after Non-Final Action
Nov 15, 2025
Non-Final Rejection — §112 (current)

Precedent Cases

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

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Prosecution Projections

3-4
Expected OA Rounds
52%
Grant Probability
67%
With Interview (+15.3%)
3y 3m
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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