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 .
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1 – 6 and 16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tang et al. (CN 101540351).
(Claim 1) Tang et al. teach a surface treatment method for forming a passivated contact of a solar cell, the solar cell comprising a silicon layer having a textured surface, the method comprising:
(i) etching a portion of the silicon layer using a first etchant (15wt % NaOCl) to reduce surface protrusions of the textured surface and to provide an intermediate surface of the silicon layer (Preferred Embodiment ); and
(ii) etching the intermediate surface of the silicon layer using a second etchant (5wt % NaOCl) to form a treated surface of the silicon layer having a desired roughness for forming the passivated contact of the solar cell, the second etchant having a slower etching rate on silicon than that of the first etchant (Preferred Embodiment).
Claim 2) Tang et al. teach the method, further comprising etching the silicon layer anisotropically to form the textured surface of the silicon layer (NaOCl etching of silicon is inherently anisotropic).
(Claim 3) Tang et al. teach wherein the second etchant is a single component etching solution (Preferred Embodiment, alcohol and water are not etchants).
(Claim 4) Tang et al. teach wherein the second etchant includes sodium hypochlorite (NaOCI, Preferred Embodiment).
(Claim 5) Tang et al. teach wherein the step (ii) of the method is performed at a temperature of 30 *C to 85 *C for a duration of 5 minutes to 15 minutes (Preferred Embodiment).
(Claim 6) Tang et al. teach wherein a concentration of the NaOCI is in a range of 10 % to 15 % by weight (Preferred Embodiment).
(Claim 16) Tang et al. teach wherein the method is performed using a batch wet chemical tool or an inline wet chemical tool.
Claims 1 – 3, 7, 8 and 16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Harrington et al. (US 2019/0207040).
(Claim 1) Harrington et al. teach a surface treatment method for forming a passivated contact of a solar cell, the solar cell comprising a silicon layer having a textured surface, the method comprising:
(i) etching a portion of the silicon layer using a first etchant (KOH) to reduce surface protrusions of the textured surface and to provide an intermediate surface of the silicon layer (paragraph 41); and
(ii) etching the intermediate surface of the silicon layer using a second etchant (KOH) to form a treated surface of the silicon layer having a desired roughness for forming the passivated contact of the solar cell (paragraphs 44, 45), the second etchant having a slower etching rate on silicon than that of the first etchant (paragraph 47).
(Claim 2) Harrington et al. teach the method, further comprising etching the silicon layer anisotropically to form the textured surface of the silicon layer (KOH etching of silicon is inherently anisotropic).
(Claim 3) Harrington et al. teach wherein the second etchant is a single component etching solution (paragraphs 44, 45).
(Claim 7) Harrington et al. teach wherein the desired roughness of the treated surface of the silicon layer is in a range of 0.2 micron to 0.5 microns (paragraphs 47 – 52).
(Claim 8) Harrington et al. teach wherein the silicon layer (fig. 2 #200) has a front side (204) arranged to receive incident light and a rear side (202), the silicon layer is doped (paragraph 37) on both the front side and the rear side in a process for forming an emitter on the front side of the silicon layer,
the step (i) of the method is adapted to etch away a doped layer of the silicon layer on the rear side for forming the passivated contact on the rear side of the silicon layer (fig. 2B, paragraph 38).
(Claim 16) Tang et al. teach wherein the method is performed using a batch wet chemical tool or an inline wet chemical tool (paragraph 29).
Claim Rejections - 35 USC § 103
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.
Claims 9 – 10 are rejected under 35 U.S.C. 103 as being unpatentable over Harrington et al. (US 2019/0207040) in view of Basu et al. (US 2015/0044812).
(Claim 9) Harrington et al. lack wherein the process includes doping the silicon layer using a boron dopant source, the first etchant includes a mixture of hydrofluoric (HF) and nitric acid (HNO3).
However, Basu et al. teach wherein the process includes doping the silicon layer using a boron dopant source (paragraphs 20, 43), the first etchant includes a mixture of hydrofluoric (HF) and nitric acid (HNO3) as conventional in the art (paragraph 5).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the references as conventional in the art.
(Claim 10) Harrington et al. lack the method, further comprising depositing a masking layer on the front side of the silicon layer after the silicon layer is doped and prior to the step (i) of the method to protect a doped layer of the front side of the silicon layer.
However, Basu et al. teach the method, further comprising depositing a masking layer on the front side of the silicon layer after the silicon layer is doped and prior to the step (i) of the method to protect a doped layer of the front side of the silicon layer for the benefit of achieving selective etching (paragraphs 4, 5).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the references for the benefit of achieving selective etching.
Claims 11 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (CN 101540351) in view of Harrington et al. (US 2019/0207040).
(Claim 11) Tang et al. lack wherein the first etchant includes a potassium hydroxide (KOH) solution or a mixture of hydrofluoric (HF) and nitric acid (HNO3).
However, Harrington et al. teach wherein the first etchant includes a potassium hydroxide (KOH) solution or a mixture of hydrofluoric (HF) and nitric acid (HNO3) for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell (paragraphs 38 – 39).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the references for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell.
(Claim 12) Tang et al. lack wherein the first etchant includes the KOH solution, the concentration of KOH is in a range of 2 % to 20 % by weight.
However, Harrington et al. teach wherein the first etchant includes the KOH solution, the concentration of KOH is in a range of 2 % to 20 % by weight (paragraph 41) for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell (paragraphs 38 – 39).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the references for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell.
Claims 11 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (CN 101540351) in view of Zhou et al. (CN 106299031),
(Claim 11) Tang et al. lack wherein the first etchant includes a potassium hydroxide (KOH) solution or a mixture of hydrofluoric (HF) and nitric acid (HNO3).
However, Zhou et al. teach wherein the first etchant includes a potassium hydroxide (KOH) solution or a mixture of hydrofluoric (HF) and nitric acid (HNO3) (Claim 7) for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell (Abstract).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the references for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell.
(Claim 14) Tang et al. lack wherein the first etchant includes the mixture of HF and HNO3, the concentration of HF is in a range of 2 % to 10% by weight and the concentration of HNO3 is in a range of 25 % to 45 % by weight.
However, Zhou et al. teach wherein the first etchant includes the mixture of HF and HNO3, the concentration of HF is in a range of 2 % to 10% by weight and the concentration of HNO3 is in a range of 25 % to 45 % by weight (Claim 7) for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell (Abstract).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the references for the benefit of texturizing the surface, thereby decreasing reflectance and increasing the efficiency of the solar cell.
Allowable Subject Matter
Claims 13 and 15 are 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.
(Claim 13) wherein the step (i) of the method is performed at a temperature of 30 *C to 85 *C for a duration of 15 seconds to 3 minutes.
(Claim 15) wherein the step (i) of the method is performed at a temperature of 18 *C to 30 *C for a duration of 30 seconds to 3 minutes.
Conclusion
Prior art made of record and not relied upon, considered pertinent to applicant's disclosure are listed in PTO – 892 Form.
Contact Information
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/IGWE U ANYA/Primary Examiner, Art Unit 2891
December 6, 2025