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 .
Election/Restrictions
Applicant’s election without traverse of Group I, Species A1 (claims 1-19) in the reply filed on December 2, 2025 is acknowledged.
Claims 20-22 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention or species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on December 2, 2025.
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 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.
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.
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) 2-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent App. Pub. No. 2013/0252427 to Song as applied to claim 1 above, and further in view of U.S. Patent App. Pub. No. 2011/0079250 to Reinhardt et al.
Song is relied upon as discussed above with respect to the rejection of claim 1.
As to claim 2, while Song discloses that the step of pre-oxidizing the substrate comprises cleaning the substrate with a cleaning solution wherein the cleaning solution is an acid solution containing HCl 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), Song does not explicitly disclose that the step of pre-oxidizing the substrate includes a pre-cleaning the substrate with a pre-cleaning solution before the cleaning of the substrate with the cleaning solution wherein the pre-cleaning solution is an acid solution containing HCl and no other acid forming component. 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]).
As to claims 3-5, 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%) and the cleaning solution can have an HCl concentration of around 12% (see Song paragraph [0017] disclosing a Hcl:H2O2:H2O ratio of 1:1:6; 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.
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 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.
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).
Conclusion
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