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 Amendment
Claims 1 and 3-22 are pending, claim 2 having been cancelled and claims 20-22 having been withdrawn. Applicant's response filed April 29, 2026 is acknowledged.
Claims 1 and 3-19 will be examined on the merits.
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 3-10 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.
Claims 3-10 depend on cancelled claim 2. The claims will be interpreted as depending on claim 1. Appropriate correction is required.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 4-9 and 11-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent App. Pub. No. 2013/0252427 to Song in view of U.S. Patent App. Pub. No. 2011/0079250 to Reinhardt et al.
As to claim 1, Song discloses a method for cleaning a semiconductor substrate for a solar cell (see Song paragraph [0016]), the method comprising: providing a semiconductor substrate (see Song Fig. 1, ref.#100, paragraphs [0016]-[0017]); pre-oxidizing the substrate with a pre-oxidizing solution wherein the pre-oxidizing solution is configured to remove metal ions from the surface of the substrate prior to the formation of the oxide on the substrate’s surface and wherein the pre-oxidizing solution is an acid solution comprising hydrogen chloride and no other acid forming component (see Song Fig. 1, ref.#102; paragraphs [0016]-[0017] where substrates are immersed in RCA-2 solution (HCl/H2O2) removes metallic particles on the surface); oxidizing the substrate with an oxidizing solution to form an oxide on the surface of the substrate (see Song Fig. 1, ref.#108; paragraphs [0016]-[0017] where a solution containing HF and HNO3 is used); and removing the oxide from the surface of the substrate with an oxide removing solution (see Song Fig. 1, ref.#112; paragraphs [0016]-[0017] where diluted HF and HCL is used to strip off the surface oxide and metallic particles). Regarding the recitation of oxidizing the substrate to form an oxide on the substrate surface, Song discloses use of an HF/HNO3 solution and a following step of removing the oxide from the substrate surface. Since Song discloses the use of HF on the substrate surface, which is the same component used in the present application as the oxidizing solution, and Song discloses that oxide is removed in the subsequent step, it is inherent or reasonably expected that the use of HF/HNO3 on the substrate oxidizes the substrate surface to form an oxide that is later removed.
Song does not explicitly disclose that the step of pre-oxidizing the substrate includes pre-cleaning the substrate with a pre-cleaning solution followed by cleaning the substrate with a cleaning solution and wherein each of the pre-cleaning and cleaning solutions are acid solutions comprising hydrogen chloride and no other acid forming component and are configured to remove metal ions from the surface of the substrate prior to the oxidizing step. Reinhardt discloses a similar method wherein a pre-cleaning step with HCl and no other acid forming component is included (see, e.g., Reinhardt paragraph [0012]). It would have been obvious to one of ordinary skill in the art at the time of filing to modify Song to include a pre-cleaning step with HCl as disclosed by Reinhardt in order to improve cleaning by removing more contamination (see Reinhardt paragraph [0012]). While Reinhardt does not explicitly disclose two HCl rinsing steps (a pre-cleaning and cleaning step), duplication of steps is prima facie obvious (see In re Citron, 326 F.2d 418 (1964) (mere duplication of steps without change in function is obvious) and it would have been obvious to one of ordinary skill in the art at the time of filing to duplicate the HCl rinsing step as disclosed by Reinhardt in the combination of Song and Reinhardt and the results would have been prima facie obvious absent secondary considerations.
As to claims 4 and 5, the combination of Song and Reinhardt discloses that the pre-cleaning solution can be a dilute HCl solution (see Reinhardt paragraph [0012] and [0036] disclosing a dilute HCl bath and paragraph [0029] disclosing that dilute rinses can have a HCl at a concentration of 0.01-1%, extendable to 0.001 to 15%; see also MPEP 2144.05(II)(A) where differences in concentration or temperature will not support patentability unless there is evidence indicating such concentration or temperature is critical and where the general conditions of the claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
As to claims 6-8, Song discloses that the pre-oxidation step can be performed at a temperature of 70-80C (see Song paragraph [0017]). It would have been obvious to one of ordinary skill in the art at the time of filing to have the pre-cleaning step have substantially the same temperature as the cleaning step and the results would have been predictable since heated cleaning is known in the art to improve cleaning as evidenced by Song using heated cleaning solution. Furthermore, the temperature range of 70-80C meets the claimed limitations of claim 7 (heated to a temperature of at least 20C) and claim 8 (at a temperature of at least 15C).
As to claim 9, Song discloses a DI rinse between different processing steps (see Song Fig. 1). It would have been obvious to one of ordinary skill in the art at the time of filing to include a DI rinsing step between the pre-cleaning and cleaning steps in order to remove any residual contaminants or components.
As to claims 11 and 12, Song discloses that the method can further comprise directing a drying fluid at the substrate, the drying fluid being configured to remove remaining solution from the surface and wherein the drying fluid can be an inert gas (see Song Fig. 1, ref.#125; paragraphs [0016]-[0017] disclosing hot nitrogen gas drying).
As to claim 13, Song discloses the use of hot nitrogen gas for drying (see Song paragraphs [0016]-[0017] and is considered to generally disclose the conditions of the claim (see MPEP 2144.05(II)(A) where differences in concentration or temperature will not support patentability unless there is evidence indicating such concentration or temperature is critical and where the general conditions of the claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
As to claim 14, Song discloses further a rinsing step prior to directing the drying fluid at the substrate, wherein the rinsing step comprises directing DI water at the substrate (see Song Fig. 1, ref.#122; paragraphs [0016]-[0017]).
As to claim 15, Song does not disclose heating the DI water rinse and thus it is reasonably expected that the DI water temperature is around room temperature and falls within the recited ranges (see also MPEP 2144.05(II)(A) where differences in concentration or temperature will not support patentability unless there is evidence indicating such concentration or temperature is critical and where the general conditions of the claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
As to claim 16, Song discloses the method can further comprise a rinsing step which is performed between the pre-oxidizing and oxidizing method steps and/or between the oxidizing and removing method steps (see Song Fig. 1, ref.#104, 110, 114 and/or 118; paragraphs [0016]-[0017]).
As to claim 17, Song discloses that the step of oxidizing the substrate can comprise configuring the oxidizing solution with HF (see Song Fig. 1, ref.#108; paragraphs [0016]-[0017] where a solution containing HF and HNO3 is used).
As to claim 18, Song discloses that the oxidizing solution can comprise a HF solution wherein the solution contains HF (49-50%) and HNO3 (70%) at a concentration about 1:25 (see Song paragraph [0016]) and is considered to generally disclose the general conditions of the claim (see MPEP 2144.05(II)(A) where differences in concentration or temperature will not support patentability unless there is evidence indicating such concentration or temperature is critical and where the general conditions of the claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation).
As to claim 19, Song discloses that at least one of the pre-oxidizing, oxidizing, and removing method steps can comprise immersing the substrate into the associated solution (see Song paragraphs [0016]-[0017]).
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent App. Pub. No. 2013/0252427 to Song in view of U.S. Patent App. Pub. No. 2011/0079250 to Reinhardt et al. as applied to claim 2 (read as claim 1) above, and further in view of CN104993011A to Gao et al. (see machine translation).
Song and Reinhardt are relied upon as discussed above with respect to the rejection of claim 2 (read as claim 1).
As to claim 10, the combination of Song and Reinhardt does not explicitly disclose that the oxidizing solution comprises a HCl concentration of at least 0.001 wt.%. Gao discloses a similar solar cell cleaning method wherein HCl is included to oxidize a semiconductor substrate surface (see Gao paragraph [0041]). It would have been obvious to one of ordinary skill in the art at the time of filing to include HCl in the oxidizing solution as disclosed by Gao and the results would have been predictable (cleaning of the semiconductor substrate of a solar cell).
Response to Arguments
Applicant's arguments filed April 29, 2026 have been fully considered but they are not persuasive.
Regarding Applicant’s arguments that the cited prior art does not disclose that the pre-oxidizing set includes a pre-cleaning the substrate with a pre-cleaning solution followed by a cleaning the substrate with a cleaning solution wherein each of the pre-cleaning and cleaning solutions are acid solutions comprising HCl and no other acid forming components and configured to not to oxidize the surface of the substrate, as discussed in the rejections above, the cited prior art, Reinhardt, discloses a similar method wherein a pre-cleaning step with HCl and no other acid forming component is included (see, e.g., Reinhardt paragraph [0012]). It would have been obvious to one of ordinary skill in the art at the time of filing to modify Song to include a pre-cleaning step with HCl as disclosed by Reinhardt in order to improve cleaning by removing more contamination (see Reinhardt paragraph [0012]). While Reinhardt does not explicitly disclose two HCl rinsing steps (a pre-cleaning and cleaning step), duplication of steps is prima facie obvious (see In re Citron, 326 F.2d 418 (1964) (mere duplication of steps without change in function is obvious) and it would have been obvious to one of ordinary skill in the art at the time of filing to duplicate the HCl rinsing step as disclosed by Reinhardt in the combination of Song and Reinhardt and the results would have been prima facie obvious absent secondary considerations.
Allowable Subject Matter
Regarding claim 3, the cited prior art does not appear to disclose or suggest fairly that the pre-cleaning solution and the cleaning solution have different concentrations of HCl where the HCl concentration in the cleaning solution is greater than in the pre-cleaning solution. Assuming that Applicant addresses the 112 rejection above and have claim 3 depend on claim 1, claim 3 would only be objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 DOUGLAS LEE whose telephone number is (571)270-3296. The examiner can normally be reached M-F 7:30-4:30pm.
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/DOUGLAS LEE/Primary Examiner, Art Unit 1714
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