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 Interpretation
It is noted that with regard to the limitation “wherein the first regions and the second regions are comprised in the back surface” in claim 1, the limitation is interpreted in a manner consistent with the description in paragraph [0084] of the as-filed specification in which the regions exist in the back surface of the substrate.
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.
Claims 1-3 and 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 11,489,080).
Regarding claim 1, Chen discloses a back contact solar cell (Fig. 9) comprising: a silicon substrate (C7/L39); a first doped semiconductor layer on a back surface of the silicon substrate in first regions (20 in Fig. 9; C13/L9); and a second doped semiconductor layer on the back surface of the silicon substrate in second regions (30 in Fig. 9; C13/L9), wherein the first regions and the second regions are comprised in the back surface and are alternately distributed at intervals (shown in annotated Fig. 9 below), wherein a conductivity type of the first doped semiconductor layer is opposite to a conductivity type of the second doped semiconductor layer (C13/L11), wherein the back surface of the silicon substrate comprises an isolation region, wherein the isolation region is located between a first region of the first regions and a second region of the second regions adjacent to the first region, and the isolation region separates the first doped semiconductor layer and the second doped semiconductor layer (shown in annotated Fig. 9 below), and wherein: a surface of at least one of the second regions is recessed into the silicon substrate relative to a surface of at least one of the first regions (shown in annotated Fig. 9 below); a surface of the isolation region is recessed into the silicon substrate relative to a surface of at least one of the second regions (shown in annotated Fig. 9 below).
While Chen does disclose a trench provided between the first and second doped regions in order to realize blocking between the first and second doped regions (C18/L27-30; C20/L23), Chen does not explicitly disclose a depth by which the surface of the isolation region is recessed into the silicon substrate relative to the surface of the at least one of the first regions is less than 3000 nm.
As the manufacturing cost and efficiency of operation are variables that can be modified, among others, by adjusting said depth by which the surface of the isolation region is recessed into the silicon substrate relative to the surface of the at least one of the first regions, with said manufacturing cost and efficiency of operation both increasing as the depth of the recess is increased, the precise depth of the recess would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed depth of the recess cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the depth of the recess in the device of Chen to obtain the desired balance between the manufacturing cost and the operation efficiency (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Additionally, with regard to the limitation “a depth by which the surface of the isolation region is recessed into the silicon substrate relative to the surface of the at least one of the first regions is less than 3000 nm,” it would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the trench of Chen such that a depth by which the surface of the isolation region is recessed into the silicon substrate relative to the surface of the at least one of the first regions is less than 3000 nm, because such a modification would have involved a mere change in the size (or dimension) of a component. A change in size (dimension) is generally recognized as being within the level of ordinary skill in the art. In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955). Where the only difference between the prior art and the claims is a recitation of relative dimensions of the claimed device, and the device having the claimed dimensions would not perform differently than the prior art device, the claimed device is not patentably distinct from the prior art device, 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).
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Regarding claim 2, modified Chen discloses all the claim limitations as set forth above. It is noted that while Chen does disclose a surface shape of the trench that is in contact with the silicon substrate 10 may further have a rough texture structure disposed thereon, the disclosure encompasses a surface shape of the trench which does not have a rough texture structure due to the word “may” in the disclosure (Chen - C18/L34-36). Therefore, the limitation “a roughness of the surface of the isolation region is less than or equal to 30 microns per 10000 square micrometers” is satisfied by the disclosure of Chen because the range claimed includes a roughness of zero to 30 microns per 10000 square micrometers. Additionally, with regard to the limitation “a length of the isolation region along an arrangement direction of the first regions and the second regions is greater than or equal to 20 microns and less than or equal to 110 microns,” it is noted that the claimed isolation region is not defined in terms of the type of isolation, the material/composition it is comprised of, or a structural boundary; but instead is simply required to be a region between a first region and a second region, therefore, any portion between the first region and the second region satisfy the limitation “isolation region.” Such a modification would have involved a mere change in the size (or dimension) of a component. A change in size (dimension) is generally recognized as being within the level of ordinary skill in the art. In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955). Where the only difference between the prior art and the claims is a recitation of relative dimensions of the claimed device, and the device having the claimed dimensions would not perform differently than the prior art device, the claimed device is not patentably distinct from the prior art device, 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).
Regarding claim 3, modified Chen discloses all the claim limitations as set forth above. Modified Chen further discloses the surface of the at least one of the second regions is a planar surface (shown in annotated Fig. 9 above).
While modified Chen does not explicitly disclose a depth by which the surface of the at least one of the second regions is recessed into the silicon substrate is greater than or equal to 100nm and less than or equal to 1000 nm; and a depth by which the surface of the isolation region is recessed into the silicon substrate relative to the surface of the at least one of the second regions is greater than or equal to 300 nm and less than 2000 nm, such a modification would have involved a mere change in the size (or dimension) of a component. A change in size (dimension) is generally recognized as being within the level of ordinary skill in the art. In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955). Where the only difference between the prior art and the claims is a recitation of relative dimensions of the claimed device, and the device having the claimed dimensions would not perform differently than the prior art device, the claimed device is not patentably distinct from the prior art device, 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).
Regarding claim 5, modified Chen discloses all the claim limitations as set forth above. Modified Chen further discloses a surface passivation layer covering the first doped semiconductor layer, the second doped semiconductor layer, and the isolation region (50 in annotated Fig. 9 above); and a first passivation layer between the first regions and the first doped semiconductor layer (C8/L23; C13/L19-21), wherein the first passivation layer is a tunneling passivation layer (C8/L23), the first doped semiconductor layer is a doped polysilicon layer (C11/L19-21; C13/L19-21).
It is noted that with regard to the limitations “passivation” and “tunneling”, the structure described in modified Chen is capable of performing the functions disclosed and therefore satisfies the limitations as claimed.
Regarding claim 6, modified Chen discloses all the claim limitations as set forth above. Modified Chen further discloses a second passivation layer between the second regions and the second doped semiconductor layer (C8/L23; C11/L27-29; C13/L19-21; porous layer depicted in Fig. 10 between the surface of the second region (shown in annotated Fig. 9 above) and second doped semiconductor layer 30), wherein the second passivation layer is a tunneling passivation layer (C8/L23; C11/L27-29), the second doped semiconductor layer is a doped polysilicon layer (C11/L19-21; C13/L19-21).
It is noted that with regard to the limitations “passivation” and “tunneling”, the structure described in modified Chen is capable of performing the functions disclosed and therefore satisfies the limitations as claimed.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 11,489,080) in view of Li et al. (CN 106784161 A – see attached machine translation).
Regarding claim 7, Chen discloses a back contact solar cell (Fig. 9) comprising: a silicon substrate (C7/L39); a first doped semiconductor layer on a back surface of the silicon substrate in first regions (20 in Fig. 9; C13/L9); and a second doped semiconductor layer on the back surface of the silicon substrate in second regions (30 in Fig. 9; C13/L9), wherein the first regions and the second regions are comprised in the back surface and are alternately distributed at intervals (shown in annotated Fig. 9 below), wherein a conductivity type of the first doped semiconductor layer is opposite to a conductivity type of the second doped semiconductor layer (C13/L11), wherein the back surface of the silicon substrate comprises an isolation region, wherein the isolation region is located between a first region of the first regions and a second region of the second regions adjacent to the first region, and the isolation region separates the first doped semiconductor layer and the second doped semiconductor layer (shown in annotated Fig. 9 above).
While Chen does disclose a first side surface of the first doped semiconductor layer close to the isolation region is textured (C18/L34-52), Chen does not explicitly disclose a first side surface of the first doped semiconductor layer close to the isolation region or a second side surface of the second doped semiconductor layer close to the isolation region is wave-shaped.
It is noted that Chen does disclose the means of texturing includes but is not limited to an alkali polished surface (C18/L38-39). It is further noted that paragraph [0125] of the as-filed specification describes a wet chemical etching solution used in the wet chemical process may be an alkaline wet chemical etching solution, the wet chemical process with a process temperature of greater than or equal to 60°C and less than or equal to 80°C, and a process time of greater than or equal to 40 sec and less than or equal to 200 seconds, and a volume proportion of an alkaline component (for example, NaOH or KOH) in the alkaline wet chemical etching solution may be greater than or equal to 2% and less than or equal to 20%.
Li discloses a solar cell and further discloses a wet chemical process with a process temperature of greater than or equal to 60°C and less than or equal to 80°C ([0028]), and a process time of greater than or equal to 40 sec and less than or equal to 200 seconds ([0028]), and a wet chemical etching solution used in the wet chemical process may be an alkaline wet chemical etching solution, and a volume proportion of an alkaline component (for example, NaOH or KOH) in the alkaline wet chemical etching solution may be greater than or equal to 2% and less than or equal to 20% ([0028]).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to achieve the alkali polished surface of Chen using the process parameters disclosed by Li, because as evidenced by Li, the use of the wet chemical process disclosed amounts to the use of a known method in the art for its intended purpose to achieve an expected result, and one of ordinary skill in the art would have a reasonable expectation of success when achieving the alkali polished surface of Chen using the disclosed wet chemical process based on the teaching of Li.
With regard to the limitation “at least one of a first side surface of the first doped semiconductor layer close to the isolation region or a second side surface of the second doped semiconductor layer close to the isolation region is wave-shaped,” as set forth above both modified Chen and the as-filed specification disclose similar process parameters for the alkali etch process, and when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977).
Response to Arguments
Applicant's arguments filed 12/31/2025 have been fully considered but they are not persuasive. Specifically, Applicant argues that the claimed depth range of “less than 3000 nm” is not merely an arbitrary change in dimension but provides specific, unexpected technical benefits as described in detail in the specification.
In response to Applicant’s arguments, unexpected results must be established by
factual evidence; mere argument or conclusory statements in the specification do not suffice. In re Geisler, 116 F.3d 1465, 1470, 43 USPQ2d 1362, 1365 (Fed. Cir. 1977) (quoting In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984)).
Applicant’s argument is not persuasive because Applicant’s assertions of unexpected results constitute mere argument (MPEP 716.01(c)). Unexpected results must be established by factual evidence (MPEP 716.01(c)). Mere conclusions in the as-filed specification and Applicant’s Remarks, without evidence in support of the assertions, are insufficient in showing the criticality of the claimed range. MPEP 716.02(d) II. states “To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside of the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).” It is also well settled that where patentability is predicated upon a change in a condition of a prior art composition, such as a change in size, concentration or the like, the burden is on the applicant to establish with objective evidence that the change is critical, i.e., it leads to a new, unexpected result. In re Woodruff 919 F.2d 1575, 1578 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456 (CCPA 1955).
Applicant argues that paragraphs [0148]-[0151] provide examples demonstrating the improvements in performance achieved with the claimed depth range.
In response to Applicant’s argument, paragraphs [0148]-[0151] do not compare a sufficient number of tests both inside and outside of the claimed range to show the criticality of the claimed range.
Further, it is noted that Applicant’s comparison of the range of “less than 3000 nm” with a range of “more than 5 microns” would not demonstrate the criticality of the range “less than 3000 nm” because values between 3000 nm and 5 microns have not been considered. For example, Applicant has not shown the results achieved from a range of “less than 3000 nm” are different than results achieved at 3500 nm.
Applicant argues that Examiner’s assertion that “manufacturing cost and efficiency of operation” would be result-effective variables influenced by the recess depth is not supported by evidence of record.
In response to Applicant’s argument, as set forth in the office action, Chen discloses a trench provided between the first and second doped regions in order to realize blocking between the first and second doped regions (C18/L27-30; C20/L23). Additionally, there is necessarily a manufacturing cost associated with producing the disclosed trench. This position is supported by Applicant’s argument on page 11 of 13 of the Remarks filed 12/31/2025 which asserts that deeper recesses generally require more processing time and material removal which typically increases cost rather than decreases it.
Therefore, Applicant’s argument that manufacturing cost and efficiency of operation as result-effective variables influenced by the recess depth is not supported by evidence of record is not persuasive.
Applicant argues that this reasoning does not address the specific technical problem solved by the claimed range: improving carrier collection efficiency by reducing carrier movement distances around isolation regions. Applicant further asserts that this is not merely a matter of manufacturing cost or general “efficiency of operation” but relates to a specific technical advantage that produces measurable improvements in device performance.
In response to Applicant’s argument, as set forth above, Applicant unexpected results must be established by factual evidence; mere argument or conclusory statements in the specification do not suffice. In re Geisler, 116 F.3d 1465, 1470, 43 USPQ2d 1362, 1365 (Fed. Cir. 1977) (quoting In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984)).
Additionally, mere conclusions in the as-filed specification and Applicant’s Remarks, without evidence in support of the assertions, are insufficient in showing the criticality of the claimed range. MPEP 716.02(d) II. states “To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside of the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).” It is also well settled that where patentability is predicated upon a change in a condition of a prior art composition, such as a change in size, concentration or the like, the burden is on the applicant to establish with objective evidence that the change is critical, i.e., it leads to a new, unexpected result. In re Woodruff 919 F.2d 1575, 1578 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456 (CCPA 1955).
Further, in response to Applicant’s argument that the reasoning does not address the specific technical problem; the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Applicant argues that deeper recesses generally require more processing time and material removal which typically increases cost rather than decreases it. Applicant further asserts that this inconsistent reasoning further demonstrates that the rejection is not based on proper technical understanding but rather on impermissible hindsight.
In response to Applicant’s argument, Applicant’s assertion that deeper recesses generally require more processing time and material removal which typically increases costs rather than decrease it, supports the position set forth in the office action that as the manufacturing cost and efficiency of operation are variables that can be modified, among others, by adjusting said depth by which the surface of the isolation region is recessed into the silicon substrate relative to the surface of the at least one of the first regions, with said manufacturing cost and efficiency of operation both increasing as the depth of the recess is increased, the precise depth of the recess would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed depth of the recess cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the depth of the recess in the device of Chen to obtain the desired balance between the manufacturing cost and the operation efficiency (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
The position set forth in the Office action does not assert that deeper recesses decrease cost. Instead, as set forth in the Office action, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the depth of the recess in the device of Chen to obtain the desired balance between the manufacturing cost and the operation efficiency (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
In response to Applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Applicant argues that as discussed in the specification at paragraphs [0018]-[0020] and [0110]-[0111], the wave-shaped side surfaces provide specific technical benefits, including improved carrier collection efficiency and reduced defects.
Applicant’s argument is not persuasive because Applicant’s assertions of unexpected results constitute mere argument (MPEP 716.01(c)). Unexpected results must be established by factual evidence (MPEP 716.01(c)). Mere conclusions in the as-filed specification and Applicant’s Remarks, without evidence in support of the assertions, are insufficient in showing the criticality of the claimed range. MPEP 716.02(d) II. states “To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside of the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960).” It is also well settled that where patentability is predicated upon a change in a condition of a prior art composition, such as a change in size, concentration or the like, the burden is on the applicant to establish with objective evidence that the change is critical, i.e., it leads to a new, unexpected result. In re Woodruff 919 F.2d 1575, 1578 (Fed. Cir. 1990); In re Aller, 220 F.2d 454, 456 (CCPA 1955).
Applicant argues that the rejection of claim 7 relies on inherency from similar processes, but fails to establish that the processes disclosed in Chen and Li would necessarily result in the specific wave-shaped surfaces with the comparative characteristics recited in dependent claims 8 and 9.
In response to Applicant’s argument, claims 8 and 9 are cancelled in the claims currently presented for examination. Additionally, Applicant has not provided reasoning or an explanation detailing the difference between the process described in the as-filed specification and the process disclosed in the prior art references which would lead one skilled in the art to expect a different structure. As set forth in the office action, with regard to the limitation “at least one of a first side surface of the first doped semiconductor layer close to the isolation region or a second side surface of the second doped semiconductor layer close to the isolation region is wave-shaped,” as set forth above both modified Chen and the as-filed specification disclose similar process parameters for the alkali etch process, and when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977).
It is noted that claim 7 recites “wherein at least one of a first side surface of the first doped semiconductor layer close to the isolation region or a second side surface of the second doped semiconductor layer close to the isolation region is wave-shaped.” Applicant’s argument directed to wave-shaped surfaces with specific comparative fluctuation amplitudes and frequencies is therefore moot.
Conclusion
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/TAMIR AYAD/Primary Examiner, Art Unit 1726