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 .
Status of Claims
Claims 1-17 are pending. Claim 13 is withdrawn. Claims 1-12 and 14-17 are examined below.
Election/Restrictions
Applicant's election with traverse of Species V, fig. 40/41 in the reply filed on 7/24/2026 is acknowledged. The traversal is on the ground(s) that species elections do not apply to method claims and claims directed to species must be present in the claims, not just the specification. This is not found persuasive because applicant’s position does not align with USPTO procedures. Restriction among species not claimed is allowed when “generic claims recite or encompass such a multiplicity of species that an unduly extensive and burdensome search would be necessary to search the entire scope of the claim”. See MPEP 808.01(a). In the instant case, where the process deviates among the disclosed species to the extent shown in the figures, it is the examiner’s position that examining the scope of the claims without an elected species would require multiple rejections of the generic claim with multiple primary prior art cites, creating an undue burden.
The requirement is still deemed proper and is therefore made FINAL.
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.
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.
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 non-obviousness.
Claims 1-2 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CN 110 137 274) in view of Huang et al. (US 2022/0115545), Padhamnath et al. (US 2024/0079506) as evidenced by Li et al. (Comparative study on front emitter and rear emitter n-type silicon heterojunction solar cells: The role of folded electrical fields), and Ye et al. (CN 116 632 080)
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The above figure is a marked-up fig. 40, applicant’s elected species.
Regarding claim 1, Zhang discloses a method for preparing a solar cell (see abstract), comprising:
providing a p-type semiconductor substrate (1) (see para [0046]), the semiconductor substrate comprising a first (back) surface and a second (front) surface opposite to each other (shown in fig. 1),
the second surface comprising a passivation contact region (under the electrode 9) and a passivation region adjacent to each other (outside of the electrode region) (see marked-up fig. 1 below) (see para [0032] and [0036]);
forming a first tunneling passivation structure (6,7) on the first (back) surface, the first tunneling passivation structure (6, 7) comprising a first tunnel layer (6) and a first passivation contact layer (7) stacked in a direction away from the semiconductor substrate (shown in fig. 1, see para [0032] and [0036]),
doping of the first passivation contact layer (see para [0027], [0045])
forming a second tunnel material layer (2) and a second passivation contact material layer (3) stacked on the second surface (front);
form a mask layer on the second passivation contact material layer (3) located in the passivation contact region (see fig. below); and
processing the second passivation contact material layer (3) located in the passivation region through the mask layer (not shown as removed by etch, see para [0039]-[0044]) thereby forming a second tunneling passivation structure (2/3) located in the passivation contact region (see mark-up figure below), wherein the second tunneling passivation structure comprises a second tunnel layer (2) and a second passivation contact layer (3), and the doping the second passivation contact layer (3) (see para [0039]-[0044]).
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The above is a marked-up figure from Zhang
Zhang does not disclose providing an n-type semiconductor substrate, the doping type of the first passivation contact layer is p- type, and the doping type of the second passivation contact layer is n-type.
Below are demonstrated a p-type doped substrate (column 1), an N-type doped substrate (column 2), a front-side emitter (row 1), a back-side emitter (row 2). These constructions are very well-known in the art. See discussion below.
Four well-known constructions:
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Huang is analogous art to Zhang as Huang is directed to a tunnel oxide passivated contact solar cell comprising a first type doped substrate and a second type doped semiconductor film (emitter) (see abstract). Huang discloses that the first type doped substrate may be either N-type doped semiconductor or a P-type doped semiconductor, wherein the emitter doped semiconductor film is oppositely doped (see para [0014]-[0015]).
The court has held it would be obvious to a person having ordinary skill in the art to modify Zhang to have an n-type doped semiconductor and a p-type doped emitter as Huang discloses choosing between a finite number of identified, predictable solutions, (i.e., either an n-type doped substrate or a p-type doped substrate with an oppositely doped emitter), one of ordinary skill in the art would have found obvious to pursue the known options with a reasonable expectation of success.
Zhang as modified by Huang does not disclose a back or rear side emitter.
Padhamnath is analogous art to modified Zhang as Padhamnath discloses a tunnel oxide passivated contact solar cell comprising either an n or p doped substrate and an oppositely doped emitter (see abstract and para [0054]). Further, Padhamnath discloses the emitter may be on the front side (fig. 1A) or the rear (fig. 1B) (see para [0104], e.g. “manufacturing of n-type rear junction passivated contact solar cells using carrier selective alloyed (p.sup.+) silicon layers (e.g. the solar cell 120 of FIG. 1B)”). The reasons for choosing either a front or back side emitter is well-known in the art as evidenced by Li (see entire document). Specifically, a rear emitter junction solar cell had a higher open-circuit voltage, fill factor, and conversion efficiency (see Li Highlights, page 1).
It would be obvious for a person having skill in the art to modify the solar cell of modified Zhang to be a rear emitter solar cell, (i.e. layers 3 and 4, and substrate 1, n-type doped semiconductor, layer 7 p-type doped emitter), because a rear side emitter has certain advantages of a higher open-circuit voltage, fill factor, and conversion efficiency.
Further, Zhang does not disclose forming the mask by the method of oxidizing a surface of the second passivation contact material layer located in the passivation contact region to form a mask layer.
Ye is analogous art to modified Zhang as Ye discloses a method of forming a photovoltaic component (see abstract). Ye discloses forming a mask by oxidizing a surface of a (first) crystalline silicon layer material disposed over a (first) tunnel layer, selective etching using the mask (see para [n0063]-[n0064]).
The Courts have held that it would be obvious to a person having ordinary skill in the art to use a known technique (i.e., the laser mask method of Wang) to improve similar methods or products (i.e., the mask of Zhang), in the same way (i.e., selective etch).
Regarding claim 2, modified Zhang discloses a method according to claim 1, wherein oxidizing the surface of the second passivation contact material layer located in the passivation contact region to form the mask layer comprises: laser oxidizing the surface of the second passivation contact material layer located in the passivation contact region to form the mask layer (see Wang abstract and Zhang para [0033]-[0039], see also discussion of claim 1).
Regarding claim 17, modified Zhang discloses a method according to claim 1, wherein before forming the second tunnel material layer and the second passivation contact material layer stacked on the second surface, the method further comprises: texturizing the semiconductor substrate to form pyramidal textured structures in the second surface (see para [0014]).
Modified Zheng does not disclose the texturizing, nor the formation of the second tunnel material layer and the second passivation contact material layer on the second surface occurs after forming the first tunneling passivation structure on the first surface.
It would be obvious to a person having ordinary skill in the art to modify the preparation of the first tunneling passivation structure on the first surface to be prior to texturizing as the court has held selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results. See In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946). See also MPEP 2144.04 IV C.
Claims 3-8, 10-12 and 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang, Huang et al., Padhamnath et al., Li et al., and Ye et al. as applied to claim 1 above, and further in view of Xu et al. (US 2024/0395963).
Regarding claim 3, modified Zhang discloses a method according to claim 1, wherein forming the first tunneling passivation structure on the first surface comprises:
forming a first tunnel material layer (6) on the first surface; and
forming a first passivation contact material layer (7) stacked on the first tunnel material layer (see para [0021]).
Zhang as modified by Padhamnath discloses the passivation contact layer is n-type (see discussion of claim 1, Padhamnath para [0104]). Zhang discloses doping of the n-type layer comprises forming a medium layer on the passivation contact material (i.e., phosphorosilicate glass, see Zhang para [0018]-[0019]).
Zhang does not disclose the tunnel oxide layer, the polysilicon layer, and the medium layer are wraparound layers (i.e., deposited on both first and second side), therefore Zhang does not disclose removing the first tunnel material layer, the first passivation contact material layer, and the first medium layer from the second surface.
Xu is analogous art to modified Zhang as Xu discloses methods of forming a TOPCON photovoltaic cell (see abstract).
Xu discloses forming a first tunnel material layer on the first surface and the second surface (i.e., wraparound);
forming a first passivation contact material layer and a first medium layer (may be second oxide surface or phosphorosilicate (n-type)/boronsilicate glass (p-type) from doping) stacked on the first tunnel material layer; and
removing the first tunnel material layer, the first passivation contact material layer, and the first medium layer from the second surface (see Xu para [0008]-[0012]).
Further, Xu discloses p-type doping can be performed in the same manner Zhang discloses p-type doping, i.e. the dopant boron is diffused into the silicon and a borosilicate glass is obtained (see para [0080]-[0084]).
The Courts have held that it would be obvious to a person having ordinary skill in the art to use a known technique (i.e., the wraparound method followed by removal on the second surface) to improve similar methods or products (i.e., tunnel oxide, passivated contact layer and medium layer of Zhang), in the same way (i.e., to form a passivated contact).
Regarding claim 4, modified Zhang discloses a method according to claim 3, wherein forming the first passivation contact material layer and the first medium layer stacked on the first tunnel material layer comprises:
forming the first passivation contact material layer on the first tunnel material layer; performing a first heat treatment to the first passivation contact material layer to activate a dopant in the first passivation contact material layer or to diffuse the dopant into the first passivation contact material layer, and to form the first medium layer on the first passivation contact material layer (see discussion of claim 3, and Zhang para [0018]-[0019], [0021], and Padhamnath para [0104]).
Regarding claim 5,
Claim interpretation: the limitation “forming the first passivation contact material layer containing a dopant” can mean depositing the material and dopant simultaneously or depositing a material and doping as a second step. “Forming” does not limit the method to a single or dual step process.
Modified Zhang discloses a method according to claim 3, wherein forming the first passivation contact material layer and the first medium layer stacked on the first tunnel material layer comprises:
forming the first passivation contact material layer containing a dopant on the first tunnel material layer; and
forming the first medium layer on the first passivation contact material layer (see Xu para [0003], [0008]-[0012], [0080]-[0084]) wherein the silicon oxide is the medium layer).
The courts have held it would be obvious to a person having ordinary skill in the art to combine prior art elements (the polycrystalline layer of Zhang with the doping method of Xu) according to known methods (as disclosed by Xu) wherein the result is predictable (i.e., a doped polycrystalline layer)
Regarding claim 6, modified Zhang discloses a method according to claim 1, wherein forming the second tunnel material layer and the second passivation contact material layer stacked on the second surface comprises: forming the second tunnel material layer on the second surface; and forming the second passivation contact material layer and a second medium layer (medium layer may be second oxide surface or phosphorosilicate (n-type)/boronsilicate glass (p-type) stacked on the second surface (see Zheng para [0012]-[0021] and Xu [0080]-[0084]).
Zheng does not disclose the passivation contact material and the first surface and the medium layer are deposited on both sides, i.e., are wraparound layers (see discussion of claim 3).
Xu is analogous art to Zheng as Xu is directed to a TOPCON solar cell. Xu discloses a method of using a wraparound deposition and removing the unwanted layers on the second side deposition (see Xu para [0003], [0008]-[0012]). Further, Xu discloses p-type doping can be performed in the same manner Zhang discloses n-type doping, i.e. the dopant boron is diffused into the silicon and a borosilicate glass is obtained (see Xu para [0080]-[0084]).
It would be obvious to a person having ordinary skill in the art to use a wraparound method of deposition and removal on the second side of the wraparound deposition as the court has held it would be obvious to use a known technique (i.e., wraparound deposition and removal of layer on second side) to a similar device (i.e., the passivation contact material and medium layer of modified Zhang) wherein the result is predictable, (i.e., the passivation contact layer and medium layer where desired and removed where not desired).
Regarding claim 7,
Claim interpretation: applicant has named a process step “second” heat treatment. Claim 7 is dependent on claim 6 and claim 1, which do not require a “first” heat treatment. Therefore, no significance is given to the term “second”.
Modified Zheng discloses a method according to claim 6, wherein forming the second passivation contact material layer and the second medium layer stacked on the first surface and the second surface comprises: forming the second passivation contact material layer on the first surface and the second surface (see discussion of claim 6); and
performing a second heat treatment (doping) to the second passivation contact material layer to activate a dopant in the second passivation contact material layer or to diffuse a dopant into the second passivation contact material layer (see Zhang para [0012]-[0021] and Xu para [0003], [0080]-[0084]), and
to form the second medium layer (the medium layer can be the phosphorosilicate (n-type)/borosilicate (p-type) on the second passivation contact material layer) (see discussion claim 1 and 6) (see Zhang para [0012]-[0021] and Xu para [0003], [0008]-[0012] and [0080]-[0084]).
Regarding claim 8,
Claim interpretation: the limitation “forming the second passivation contact material layer containing a dopant” can mean depositing the material and dopant simultaneously or depositing a material and doping as a second step. “Forming” does not limit the method to a single or dual step process.
Modified Zhang discloses a method according to claim 6, wherein forming the second passivation contact material layer and the second medium layer stacked on the first surface and the second surface comprises: forming the second passivation contact material layer containing a dopant on the first surface and the second surface; and forming the second medium layer on the second passivation contact material layer (see discussion of layer 7) (see Zhang para [0012]-[0084] and Xu para [0003], [0008]-[0012] and [0080]-[0084]).
Regarding claim 10,
Claim interpretation: claim 10 is dependent on claims 8, 6 and 1. Claim 1 and the intervening claims do not comprise a limitation for a first and/or second heat treatment. Therefore the limitation in claim 10 specifying a “third” heat treatment, no significance is given to the term “third”.
Modified Zhang discloses a method according to claim 8, wherein after forming the second passivation contact material layer and the second medium layer stacked on the first surface and the second surface, the method further comprises: performing a third heat treatment (i.e. can be doping and/or forming an oxide mask) on the first tunneling passivation structure, the second tunnel material layer, and the second passivation contact material layer (see Zhang para [0012]-[0021] and Xu para [0003], [0008]-[0012] and [0080]-[0084]).
Regarding claim 11, modified Zhang discloses a method according to claim 6, wherein after forming the second passivation contact material layer and the second medium layer stacked on the first surface and the second surface, the method further comprises: removing the second medium layer and removing the second passivation contact material layer from the first surface (see Xu para [0008]-[0012] and [0080]-[0084], wherein the wraparound layers are removed from the opposite layer) (see discussion of claim 6).
Regarding claim 12, method according to claim 11, wherein removing the second medium layer and removing the second passivation contact material layer from the first surface comprises: removing the second medium layer from the first surface; removing the second passivation contact material layer from the first surface; and removing the second medium layer from the second surface (see discussion of claim 6 and 10) (see Zhang para [0012]-[0021] and Xu para [0008]-[0012] and [0080]-[0084]).
Regarding claim 15, modified Zhang discloses a method according to claim 6, wherein after forming the second passivation contact material layer and the second medium layer stacked on the first surface and the second surface, and before oxidizing the surface of the second passivation contact material layer located in the passivation contact region to form the mask layer, the method further comprises: removing the second medium layer (see Zhang para [0012]-[0021] and Xu para [0008]-[0021], i.e. the mask of Zhang is formed after the removal of the glass layer formed from doping, i.e., either from p-type or n-type, see discussion of claim 1).
Regarding claim 16,
Claim interpretation: claim 16 depends from claims 1, 6 and 15, which do not require a first, second, or third heat treatment. Therefore, for the limitation of a “fourth” heat treatment, no significance is given to the term “fourth”.
Modified Zhang discloses a method according to claim 15, wherein processing the second passivation contact material layer located in the passivation region through the mask layer to form the second tunneling passivation structure located in the passivation contact region comprises: removing the second tunnel material layer and the second passivation contact material layer located in the passivation region (see Zhang para [0012]-[0021]);
performing a fourth heat treatment on the first tunneling passivation structure, the second tunnel material layer, and the second passivation contact material layer (see Zhang para [0012]-[0021], wherein the heat treatment may be doping as Zhang discloses depositing the layers on the first (back side) second, which was not modified in claims 1, 16, or 15), and
removing a heat treatment by-product (i.e., borosilicate glass for p-type, see discussion of claim 1, and Xu para [0008]-[0012] and [0080]-[0084]) from the semiconductor substrate to form the second tunneling passivation structure.
Allowable Subject Matter
Claims 9 and 14 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.
The following is a statement of reasons for the indication of allowable subject matter:
Specifically, the prior art does not disclose wherein forming the second passivation contact material layer containing the dopant on the first surface and the second surface comprises: forming a first passivation contact material sub-layer on the first surface and the second surface; forming a barrier material layer on the first passivation contact material sub-layer; and forming a second passivation contact material sub-layer on the barrier material layer to form the second passivation contact material layer.
Specifically, the prior art does not disclose wherein processing the second passivation contact material layer located in the passivation region through the mask layer to form the second tunneling passivation structure located in the passivation contact region comprises: thinning the second passivation contact material layer located in the passivation region through the mask layer to form the second tunneling passivation structure located in the passivation contact region, and forming a third tunnel layer and a third passivation layer stacked in the passivation region.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Yang et al. (US 2023/0307573) (texturizing after formation of back tunnel), Wang et al. (US 2024/0266460) (activate dopant and crystallize silicon), Zhang et al. (CN116936675) (disclosed in IDS submitted 1/27/2025).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAYNE L MERSHON whose telephone number is (571)270-7869. The examiner can normally be reached 10:00 to 6:00 M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Allison Bourke can be reached at (303) 297-4684. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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JAYNE L. MERSHON
Primary Examiner
Art Unit 1721
/JAYNE L MERSHON/ Primary Examiner, Art Unit 1721
