DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114 was filed in this application after a decision by the Patent Trial and Appeal Board, but before the filing of a Notice of Appeal to the Court of Appeals for the Federal Circuit or the commencement of a civil action. Since this application is eligible for continued examination under 37 CFR 1.114 and the fee set forth in 37 CFR 1.17(e) has been timely paid, the appeal has been withdrawn pursuant to 37 CFR 1.114 and prosecution in this application has been reopened pursuant to 37 CFR 1.114. Applicant’s submission filed on 02/05/2026 has been entered.
Status
The reply filed 02/05/2026 has been entered. Claims 1-15, 17, and 21-24 are pending. In the reply filed 02/05/2026, claims 1 and 22 were amended, no claims were canceled, and no claims were newly added. Note that applicant’s claim status identifiers labeled claim 21 as “previously presented” despite containing clearly marked amendments. Applicant is kindly requested to ensure claim status identifiers are correct.
Claim Rejections - 35 USC § 112(a)
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.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
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 of carrying out his invention.
Claim 1-15, 17, and 21-24 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, 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 or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 line 15-17 and claim 21 line 15-17 recite “has an average measured conductivity determined from a plurality of conductivity measurements taken during active etching and during at least one feed or bleed event over a predetermined period of time”. This limitation represents new matter because there is no support in the instant specification for averaging conductivity measurements taken during etching AND during a feed or bleed event (i.e. there is no support for the idea of averaging the measurements during these two distinct events). The instant specification provides support for repetitive measurements during etching [0021] and also support for repetitive measurements during a feed or bleed event [0028] but does not support averaging the values of each event together. Therefore this limitation represents new matter. For purpose of examination on the merits and compact prosecution on the merits, the claims will be examined as if this limitation is supported by the instant specification as filed. This is not an indication that such support is present.
Claim 1 line 28-30 and claim 21 line 29-31 recite “the controller uses the assigned relationship to distinguish conductivity changes caused by etchant consumption during etching from conductivity changes caused by dilution during the feed or bleed”. This limitation represents new matter because there is no indication in the instant specification that the controller can distinguish between conductivity changes caused by the etchant consumption and conductivity changes caused by dilution during the feed or bleed. This limitation is neither explicitly or implicitly taught by the instant specification as originally filed. Applicant’s reply filed 02/05/2026 did not indicate where support for such an amendment was made and Examiner’s review of the specification has found no support. For purpose of examination on the merits and compact prosecution on the merits, the claims will be examined as if this limitation is supported by the instant specification as filed. This is not an indication that such support is present.
The remaining claims are included for their dependence from a claim addressed above.
Claim Rejections - 35 USC § 112(b)
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.
Claim 1-15, 17, and 21-24 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.
Regarding claim 1 and 21, the claims require in line 15-17 that the conductivity during etching and during a feed or bleed event is averaged. Then in claim 1 line 28-30 and claim 21 line 29-31 recites “the controller uses the assigned relationship to distinguish conductivity changes caused by etchant consumption during etching from conductivity changes caused by dilution during the feed or bleed”. It is unclear if applicant is intending to claim that the controller can, despite averaging the values of both events together, distinguish between the two events, or if applicant intended to claim that the controller can distinguish between the events and that the averaging is done separately for each event (i.e. measurements are averaged for etching and separately measurements are averaged for feeding/bleeding). Either interpretation represents new matter (see rejection above). For purpose of examination on the merits the claim will be examined using the interpretation that the controller can distinguish between the events and that the averaging is done separately for each event (i.e. measurements are averaged for etching and separately measurements are averaged for feeding/bleeding) because this is most consistent with the instant specification teachings despite also representing new matter.
Claim 21 recites “the assigned relationship” in line 29. There is insufficient antecedent basis for this term in the claim. For purpose of examination on the merits, the assigned relationship is interpreted as an assigned relationship between the pH, concentration, and conductivity (see line 25-28 of the claim that refers to these as correlations).
The remaining claims are included for their dependence from a claim addressed above.
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) 1-15, 17, and 21-24 is/are rejected under 35 U.S.C. 103 as being unpatentable over US Patent Application Publication 2008/0035609 of Kashkoush et al., hereinafter Kashkoush, in view of Fanjat (prev. presented US 2009/0141583) and Chow (prev. presented US 5,965,410).
Regarding claim 1, Kashkoush teaches a system (Fig 5) configured for etching at least one silicon substrate [0003] comprising: a closed-loop circulation system (Fig 5, see loop for recycling etchant) having a process chamber (10 Fig 5) and a recirculation line (40 Fig 5) fluidly coupled to the process chamber [0033], the closed-loop circulation system configured to circulate a circulation volume [0037-0038] of an etchant solution [0044] while the etchant solution is in contact with the at least one silicon substrate (wafer Fig 5) [0044-0045] and etching the at least one silicon substrate [0044-0045]; a bleed line (90 Fig 5) for bleeding a contaminated etchant solution from the circulation volume of the etchant solution [0036]; a first feed line (30 Fig 5) for adding a first fresh etchant solution to the circulation volume of the etchant solution [0033]; a concentration sensor (50 Fig 5) operably coupled to the closed-loop circulation system and configured to repetitively measure concentration [0047] of the circulation volume of the etchant solution during etching of the at least one silicon substrate [0033], [0047]; and a controller (200 Fig 5) configured so that upon detecting that the circulation volume of the etchant solution has an average measured concentration determined from a plurality of conductivity measurements taken during active etching [0047-0048] and during at least one feed or bleed event [0047-0054] over a predetermined period of time that is at or below a lower threshold of conductivity [0047-0051], the controller automatically: (1) activates the bleed line to bleed a first volume of the contaminated etchant solution from the circulation volume of the etchant solution [0018-0020]; and (2) activates the first feed line to add a first volume of the fresh etchant solution to the circulation volume of the etchant solution to increase the concentration of the circulation volume of the etchant solution to a value that is greater than the lower threshold of concentration but less than or equal to an upper threshold of concentration [0018-0020]; wherein the controller distinguishes between changes caused by etchant consumption during etching from conductivity changes caused by dilution during the feed or bleed ([0047-0051] (note that by controlling when feed and bleed occur in the same controller that is obtaining the concentration measurements, the controller can distinguish between the values because the controller program includes the data one when feed and bleed is occurring has an “awareness” of whether feeding and bleeding is occurring); and wherein the controller uses the concentration to control at least one of a timing or a volume of the feed or bleed [0018-0020]. Kashkoush fails to teach specifically using conductivity measurements for the concentration sensor and fails to teach the controller stores a set of predetermined conductivity values that have an assigned relationship to a previously measured and correlated set of pH values, etchant concentrations, and conductivity values, and wherein the predetermined conductivity values comprise the lower threshold of conductivity such that the concentration control is based on this assigned relationship. Regarding using conductivity sensors for the concentration, in the same field of endeavor of semiconductor processing systems (abstract), Fanjat teaches a conductivity sensor configured to measure conductivity of the circulation volume of the etchant solution (528 Fig 5 [0073] note that cleaning fluids are a type of etching fluid) and operably coupled to the closed-loop circulation system (Fig 5); and a controller (126 Fig 5) configured so that upon detecting that the circulation volume of the etchant solution has a conductivity over a that is at or below a lower threshold of conductivity ([0071] outside of a target range is inclusive of a lower threshold and an upper threshold and [0136]), the controller automatically: (1) activates the bleed line to bleed a first volume of the contaminated etchant solution from the circulation volume of the etchant solution [0074]; and (2) activates the first feed line to add a first volume of the fresh etchant solution to the circulation volume of the etchant solution to increase the conductivity of the circulation volume of the etchant solution to a value that is greater than the lower threshold of conductivity but less than or equal to an upper threshold of conductivity ([0088], [0090]) (note that the inclusion of NH4OH increases the conductivity of the solution). Fanjat teaches the controller stores a set of predetermined conductivity values [0065], [0067], [0091], [0136] and the predetermined conductivity values comprise the lower threshold of conductivity ([0136], note the teaching of the range includes the lower and the upper thresholds). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Kashkoush to use a conductivity sensor as the concentration sensor because this represents a simple substitution of one known element (conductivity concentration sensor of Fanjat) for another (concentration sensor of Kashkoush) to achieve predictable results (concentration detection in the closed loop system). Regarding the predetermined conductivity values have an assigned relationship to a previously measured and correlated set of pH values, etchant concentrations, and conductivity values, Fanjat teaches storing predetermined conductivity values and teaches monitoring conductivity (sensor 528 [0073]) and pH [0130] and teaches a relationship between conductivity and concentration (Fig 11), but the combination fails to teach storing a relationship between conductivity and pH and concentration. Addressing the same problem of monitoring a solution in a flowing channel using conductivity (abstract, col 1, ln 15-25), Chow teaches correlating a conductivity to a pH and concentration using a known relationship (look-up table or calculation) that is stored by the controller (col 29, ln 18-27). It would have been obvious to a person having ordinary skill in the art at the time the invention was filed to modify Kashkoush in view of Fanjat to include these relationships including pH because Fanjat has already taught relating conductivity to concentration and has taught measuring pH [0130]. It is noted that the inclusion of additional data improves the measurement by reducing the impact of additional components on the conductivity measurement.
Regarding claim 2, Kashkoush teaches controlling the temperature [0046] and teaches temperature affects the etch rate [0060] but fails to teach a temperature sensor as claimed. Fanjat teaches a temperature sensor operably coupled to the closed-loop circulation system [0075] configured to measure temperature of the circulation volume of the etchant solution [0075]. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Kashkoush to include the temperature sensor because monitoring of the temperature allows for feedback control and correction of the temperature which improves temperature control. Regarding being configured to repetitively measure, it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to modify the temperature sensor of Fanjat to repeatedly measure because Fanjat requires monitoring over the processing time (taught as maintaining a temperature during processing [0065]) and repeated measurements allow for monitoring over time.
Regarding claim 3, Kashkoush teaches a higher temperature range [0046] but is capable of being operated with lower temperatures. Fanjat teaches the temperature is maintained in the range of 25-125 °C [0087]. Note the temperature during operation is directed to the manner in which the system is intended to be operated.
Regarding claim 4, Kashkoush teaches the recirculation line includes a heater (70 Fig 5) [0046] to heat the circulation volume [0046].
Regarding claim 5, Kashkoush teaches the heater is operably coupled to the controller [0040].
Regarding claim 6, Kashkoush fails to teach a pH sensor. Fanjat teaches including a pH sensor [0130] coupled to the circulation system [0130]. Regarding the pH sensor being configured to repetitively measure, it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to modify the pH sensor of Fanjat to repeatedly measure because Fanjat requires monitoring over the processing time [0130-0131] and repeated measurements allow for monitoring over time. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Kashkoush to include the pH sensor because Fanjat teaches this is a functional additional sensor for monitoring the chemical characteristics of the liquid [0130].
Regarding claim 7, Kashkoush teaches the etchant (sulfuric acid) is 030% by weight [0048].
Regarding claim 8, Kashkoush fails to teach the claimed etchants. Fanjat teaches alternative etchants include KOH, HF, and HCl [0069]. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Kashkoush to include these etchants to increase the number and type of etching processes that may be performed by the same system and to allow for substrate cleaning (i.e. etching of residues).
Regarding claim 9, Kashkoush teaches water [0048] (Fig 5) and Fanjat teaches specifically deionized water (DIW) [0069]. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to use deionized water as the water of Kashkoush because deionized water is the standard water used in laboratories during reactions to avoid unnecessary contaminants and because Fanjat demonstrates deionized water is a known water used in substrate processing.
Regarding claim 10, the combination remains as applied to claim 1 above. In the combination as applied, the repetitively measured conductivity is used to determine an average conductivity because averaging is standard scientific principle to reduce noise in measurements.
Regarding claim 11, Kashkoush teaches maintaining at a substantially constant temperature [0038], [0046], Further Fanjat as applied in the combination teaches the etchant solution is maintained at a substantially constant temperature [0065], [0087]; and wherein the upper and lower thresholds of conductivity are based, at least in part, on the substantially constant temperature [0142] (note this teaches conductivity depends on temperature and therefore the set range of the conductivity also depends on the temperature).
Regarding claim 12-13, Kashkoush teaches a second feed line (31 Fig 1) for adding fresh etchant to the circulation line and teaches activating the second feed line to add a second volume of fresh etchant to the solution [0057].
Regarding claim 14, Kashkoush teaches the system further comprising a bleed valve (91 Fig 5) fluidly coupled to the process chamber and the bleed line (Fig 5) [0036].
Regarding claim 15, Kashkoush teaches the concentration sensor coupled to the controller (Fig 5 see dotted line indicating coupling) and Fanjat teaches the conductivity sensor (528 Fig 5) is coupled to the controller (126 536 Fig 5) [0077].
Regarding claim 17, Kashkoush teaches the controller stores parameters [0040] and Fanjat teaches the conductivity range is stored by the controller [0065], [0067], [0091], [0136].
Regarding claim 21, the combination remains as applied to the analogous limitations of claim 1 above. Fanjat teaches the conductivity range is based on a model or data [0142], such data is inclusive of previously recorded sets of date that were measured [0156-0160]. The previously recorded data (i.e. historical data) of Fanjat is inclusive of data from previous runts of the closed loop system of Fanjat. Note that in the combination as applied to claim 1, the data for conductivity includes relations to pH values and concentrations as explained above.
Regarding claim 22 and 24, Kashkoush teaches controlling the temperature [0046] and teaches temperature affects the etch rate [0060] but fails to teach a temperature sensor as claimed. Fanjat teaches a temperature sensor operably coupled to the closed-loop circulation system [0075] configured to measure temperature of the circulation volume of the etchant solution [0075]. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Kashkoush to include the temperature sensor because monitoring of the temperature allows for feedback control and correction of the temperature which improves temperature control. Regarding being configured to repetitively measure, it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to modify the temperature sensor of Fanjat to repeatedly measure because Fanjat requires monitoring over the processing time (taught as maintaining a temperature during processing [0065]) and repeated measurements allow for monitoring over time. Note that for claim 22, the previously recorded data (i.e. historical data) of Fanjat includes data regarding recorded temperatures because Fanjat has taught monitoring temperature and that temperature influences conductivity measurements [0142].
Regarding claim 23, Kashkoush teaches a second feed line (31 Fig 1) for adding fresh etchant to the circulation line and teaches activating the second feed line to add a second volume of fresh etchant to the solution [0057].
Response to Arguments
Applicant's arguments filed 02/05/2026, hereinafter reply, have been fully considered but they are not persuasive.
Regarding the amended limitations (reply p7-8), the rejection has been updated to include Kashkoush which teaches monitoring during operation and during feed/bleed events. Further the controller of Kashkoush includes both concentration monitoring and performing feed/bleed and can distinguish between concentration changes during etching or feed/bleed because the state of feed/bleed requires specific valves to be on or off and the same controller is controlling the state of these valves while receiving the concentration measurements.
Regarding Chow (reply p9), applicant argues that Chow fails to appreciate the advancement discovered by application regarding the relationships in a closed system. This is not persuasive because Fanjat has already disclosed relating concentration and conductivity and Chow renders obvious storing values of conductivity related to specific pH and concentration values. As explained above, Kashkoush teaches the monitoring of the closed system using conductivity as a monitor for concentration. If applicant believes the controller of the instant application is relying on a specific algorithm or process that is not taught by the prior art, applicant is kindly requested to incorporate such algorithm into the claim and demonstrate where support for the amendment is in the instant specification as originally filed.
For all of these reasons the arguments are not persuasive as to the patentability of the instant claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 4,745,953 teaches averaging to reduce noise in the signals (col 6, ln 45-55).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARGARET D KLUNK whose telephone number is (571)270-5513. The examiner can normally be reached Mon - Fri 9:30-5:30.
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/MARGARET KLUNK/Examiner, Art Unit 1716
/KEATH T CHEN/Primary Examiner, Art Unit 1716
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