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 Specie V (embodiment of figure 6) in the reply filed on 01/20/2026 is acknowledged.
Although applicant suggests that claims 1-10, 12-13, 15-21 and 24 read on elected specie V, pending claim set still contains claims that are directed to non-elected species.
Claim 4 requires the first heavily doped layer to be stacked on the semiconductor substrate, which is directed to non-elected embodiment (for example, fig. 5). Elected specie V (fig. 6) shows second heavily doped layer 511 is embedded within the semiconductor substrate 500.
Claims 12-13 and 17 require the second heavily doped layer to be stacked on the semiconductor substrate, which is directed to non-elected embodiment (for example, fig. 5). Elected specie V (fig. 6) shows second heavily doped layer 512 is embedded within the semiconductor substrate 500.
Claim 19 requires a tunneling oxide layer between first heavily doped layer and the semiconductor substrate, which is directed to non-elected embodiment (for example, fig. 7, tunneling oxide layer 613 between 611 and 600). Elected specie V (fig. 6) does not require a tunneling oxide layer as claimed.
Accordingly, claims 4, 12-13, 17 and 19-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected specie, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 01/20/2026.
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 1-3, 5-6, 8-10, 15-16, 18 and 24 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Hagino (US 2004/0112426 A1).
Regarding claim 1, Hagino discloses a solar cell (see figure 2 or fig. 5H, [0041-0042] and [0065-0072]), comprising:
a semiconductor substrate (silicon wafer 1, fig. 2 and [0041]),
a first heavily doped layer (back surface field layer 16, fig. 2/5H and [0041-0042]),
a front electrode (13B, fig. 2/5H, and [0071]),
an emitter layer (dopant diffusion layer 6, [0070]), and
a back electrode (8B, [0071]); wherein
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Figure 1: Solar cell of fig. 2/5H of Hagino with annotations
the semiconductor substrate (1) is first-type doped (p-type, [0041] and [0066]) and comprises includes opposing front (bottom) and back (top) surfaces (see fig. 5B);
the first heavily doped layer (16) and the front electrode (13) are disposed on the front surface (bottom) of the semiconductor substrate (1) (see fig. 2/5H),
the first heavily doped layer (16) is first-type doped (P-type via Aluminum doping, [0016], [0041], [0063] and claim 11),
a doping concentration of the first heavily doped layer (16) is higher than a doping concentration of the semiconductor substrate (1) (layer 16 has p-type Al dopant, [0063], and thus has higher Al dopant concentration) (see also [0072] that discloses the cell has n++/n+/p-/p+ structure, which implies that layer 16 has p+ or higher concentration that the substrate p-),
the first heavily doped layer (16) is disposed between the front electrode (13B) and the semiconductor substrate (1) (see annotated figure above),
the front electrode (13B) is electrically connected to the semiconductor substrate (1) through the first heavily doped layer (16);
the emitter layer (6) and the back electrode (8B) are disposed on the back surface (top surface) of the semiconductor substrate (1),
the emitter layer (6) is second-type (n-type) doped ([0070]),
the second type (n-type) is different from the first type (p-type), and
the emitter layer (6) is disposed between the back electrode (8B) and the semiconductor substrate (1) (see annotated figure 1).
Regarding claim 2, Hagino further discloses an orthographic projection of the front electrode (vertical portion of electrode 13B) on the semiconductor substrate (1) is located within an orthographic projection of the first heavily doped layer (16) on the semiconductor substrate (1) (see fig. 2/5H or annotated figure 1).
Regarding claim 3, Hagino further discloses the front electrode (13B) is in direct contact with the first heavily doped layer (16) (see fig. 2/5H or annotated figure 1).
Regarding claim 5, Hagino further discloses a portion of the first heavily doped layer (16) is embedded within the semiconductor substrate (1) (see fig. 2/5H or annotated figure 1).
Regarding claim 6, Hagino further discloses that the localized back surface filed (16) is formed by diffusing aluminum paste into the opening portion (4B) ([0016] and [0041]). Therefore, the concentration of aluminum would decrease as it moves away further from the opening portion (4B). Thus, the portion of the localized back surface filed (16) which is close to the opening portion (4B) is interpreted as the first heavily doped layer (shaded portion of 16, see annotated figure 2 below) and the portion of the localized back surface filed (16) that is away from the opening portion (4B) is interpreted as the second heavily doped layer (unshaded portion of 16, see annotated figure 2 below).
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Figure 2: Solar cell of fig. 2/5H of Hagino with annotated first and second heavily doped layers
Thus, Hagino discloses a second heavily doped layer (unshaded portion of 16) disposed on the front surface (back surface) of the semiconductor substrate (1), wherein the second heavily doped layer (unshaded portion) is first-type doped (p-type via Al doping), and a doping concentration of the second heavily doped layer (unshaded portion) is higher than the doping concentration of the semiconductor substrate (1) (because the BSF has Al doping, and the substrate does not) but lower than the doping concentration of the first heavily doped layer (shaded portion of 16); an electric field that hinders movement of front side carriers is formed between the second heavily doped layer (unshaded portion of 16) and the semiconductor substrate (1).
Regarding claim 8, Hagino further discloses an orthographic projection of the first heavily doped layer (shaded portion of 16, see annotated figure) on the semiconductor substrate (1) is located within an orthographic projection of the second heavily doped layer (unshaded portion of 16) on the semiconductor substrate (1) (see annotated figure 2).
Regarding claim 9, Hagino further discloses at least part of the first heavily doped layer (shaded portion of 16) is embedded within the second heavily doped layer (unshaded portion of 16) (see annotated figure 2).
Regarding claim 10, Hagino further discloses the first heavily doped layer (shaded portion) is spaced apart from the semiconductor substrate (1) by the second heavily doped layer (unshaded portion of 16) (see annotated figure 2).
Regarding claim 15, Hagino further discloses that the second heavily doped layer (unshaded portion of 16) is embedded within the semiconductor substrate (1), the first heavily doped layer (shaded portion of 16) is embedded within the second heavily doped layer (unshaded portion of 16), and top surfaces of the first heavily doped layer, the second heavily doped layer, and the semiconductor substrate are flush with each other (see annotated figure 2).
Regarding claim 16, Hagino further discloses that the first heavily doped layer (shaded portion of 16) is stacked on a side of the second heavily doped layer (unshaded portion of 16) away from the semiconductor substrate (1) (see annotated fig. 2).
Regarding claim 18, Hagino further discloses that the first type doping is p-type doping ([0041] and [0066]), and the second type doping is n-type doping ([0070]).
Regarding claim 24, Hagino further discloses a passivation film structure (see annotated fig. 1) disposed on the back surface (top surface), wherein the passivation film structure includes a first dielectric layer (passivation film 3A) and a second dielectric layer (antireflection film 5) sequentially stacked in a direction away from the semiconductor substrate (1) (see figure 2.5H or annotated fig.1, [0070]); wherein the first dielectric layer (3A) is a silicon oxide layer ([0028]), and the second dielectric layer (5) is an aluminum oxide layer ([0055]).
It is further noted that the limitation “a thickness of the first dielectric layer is in a range from 0.1 nm to 2 nm, and a thickness of the second dielectric layer is in a range from 3 nm to 20 nm” is optional.
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.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Hagino (US 2004/0112426 A1) as applied above, and further in view of Boukai (US 2012/0152354 A1).
Regarding claim 7, Hagino further discloses the first doped layer (shaded portion) has higher concentration than the second doped layer (unshaded portion) as concentration of aluminum would decrease as it moves away further from the opening portion (4B).
However, Hagino does not explicitly disclose a doping concentration of the first heavily doped layer is in a range from 1×1018 cm−3 to 3×1018 cm−3, and the doping concentration of the second heavily doped layer is in a range from 5×1016 cm−3 to 9×1017 cm−3.
Boukai discloses a solar cell wherein a heavily doped BSF layer is formed with a dopant concentration of 1×1018 cm−3 ([0059]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have used a dopant concentration 1×1018 cm−3 as taught by Boukai to form the BSF 16 of Hagino such that heavily doped BSF layer can be formed, as taught by Boukai and also desired by Hagino.
Thus, Hagino as modified by Boukai discloses a doping concentration of the first heavily doped layer is 1×1018 cm−3.
The dopant concentration of Al starts with at 1×1018 cm−3 at the opening portion (4B) and diminishes as it moves away from the opening portion (4B). Thus, the second doped layer has a doping concentration of less than 1×1018 cm−3, which lies or overlaps with the claimed range of 5×1016 cm−3 to 9×1017 cm−3.
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976)) (MPEP § 2144.05 - (I)).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Hagino (US 2004/0112426 A1) as applied above.
Regarding claim 21, Hagino further discloses that the emitter layer (6) includes a first region (high concentration dopant diffusion layer 6B) and a second region (low concentration dopant diffusion layer 6A) located outside the first region (6B), the back electrode (8B) is disposed on the first region (6B), and a thickness of the first region (6B) is greater than a thickness of the second region (6A) (see fig. 2 or 5H).
However, Hagino does not explicitly disclose a thickness difference between the first region and the second region is in a range from 20 nm to 120 nm.
Regarding the limitation “a thickness difference between the first region and the second region is in a range from 20 nm to 120 nm”, selection of element’s dimension is considered to be a matter of design choice, depending upon the dimensions and gradient present in the installation site, among other considerations. In the absence of evidence of criticality, selection of thicknesses of the first and second heavily doped layers as claimed is considered obvious to one having ordinary skill in the art. Also note that in Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984), the Federal Circuit held that, where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to GOLAM MOWLA whose telephone number is (571)270-5268. The examiner can normally be reached M-Th, 7am - 4pm.
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/GOLAM MOWLA/ Primary Examiner, Art Unit 1721
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