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 II in the reply filed on 11/20/2025 is acknowledged.
Claims 2-6 are withdrawn from consideration as being directed to a non-elected invention. For the purposes of maintaining consistency and ensuring proper antecedent basis for the limitations in the elected method, Claim 1 is being examined concurrently with Claims 7-10.
The restriction between the product of Group I and the process of Group II remains proper under MPEP 806.05(f). The photodetection element of Claim 1 is a structural invention that is not limited by the specific heating steps of the elected method. For example, the device defined in Claim 1 could be fabricated by materially different processes, such as Molecular Beam Epitaxy (MBE) or Chemical Vapor Deposition (CVD), which do not utilize the thermal sequence of the elected method.
Prior Art of Record
The applicant's attention is directed to additional pertinent prior art cited in the accompanying PTO-892 Notice of References Cited, which, however, may not be currently applied as a basis for the following rejections. While these references were considered during the examination of this application and are deemed relevant to the claimed subject matter, they are not presently being applied as a basis for rejection in this Office action. The pertinence of these documents, however, may be revisited, and they may be applied in subsequent Office actions, particularly in light of any amendments or further clarification of the claimed invention.
Treatment of Claims for Compact Prosecution
In the interest of compact prosecution, Claims 7-10 are being examined on the merits as if rewritten in independent form. While Claim 7 is drafted in dependent form, it is treated for the purpose of this examination as an independent claim incorporating the features of the parent claim (Claim 1) by reference. To ensure a clear and consistent record regarding the antecedent basis for "the silicon layer" and "the germanium layer" acted upon by the method, the structural limitations of Claim 1 have been considered alongside the elected process steps.
Claim Objections
Claims 7-10 are objected to because of the following informalities:
Claims 7-10 are objected to under the guidance of MPEP 821.01 as being improper in form.
While the structural limitations of Claim 1 are being considered for the purpose of providing antecedent basis for the elected process, Claim 1 remains a member of the non-elected Product Group (Group I). Under Office practice, a claim that depends from a claim of a non-elected group is improper in form. To ensure the record is clear and the elected invention is self-contained, Claim 7 should be rewritten in independent form to incorporate all the limitations of the claim(s) from which it depends.
Appropriate correction is required.
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.
Claim(s) 1, 7-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (US 20130034950 A1) in view of Akiyama et al. (US 20090061557 A1).
CLAIMS 1 & 7. Lin et al. in view of Akiyama et al. teach the method for manufacturing a photodetection element (Note: solar cell, as in Lin, is a species of the genus “photodetection element” as both are semiconductor p-n junction devices that utilize the photovoltaic effect to convert incident light into electrical energy; they are functionally equivalent for the purposes of photoelectric conversion.) comprising:
a silicon layer 10 formed in a single crystal state (Lin et al - Fig. 1C & ¶[0015]);
a germanium-containing layer 13 formed in a polycrystal state (Lin et al - Fig. 1C & ¶[0016]);;
a first electrode 40 electrically connected to the silicon layer 10; and a second electrode 11electrically connected to the germanium- containing layer 13,
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the method for manufacturing a photodetection element comprising:
a first step of performing film formation of a layer including germanium 12 on the silicon layer 10 (Lin ¶[0013]1); and
a second step of polycrystallizing the layer including germanium and forming the germanium-containing layer by heating the layer including germanium after the first step (Lin ¶[0014-15]2).
Lin may however be silent upon the capability of the layers specifically forming a PN heterojunction where the silicon layer is specifically N-type and the germanium containing layer is P-type. Solar cells such as disclosed in Lin are understood to be PN junctions. Akiyama et al. teaches solar cells with Si/Ge pn hetero junctions may specifically be doped such that the Si layer is N-type (¶[0052] - substrate 100 is N-type) and the Ge containing layer 20 layer has P-type conductivity (¶[0054] – Note: ¶54 explicitly teaches germanium containing layer 20A is opposite conductivity to that of silicon layer 10B thereby forming a PN heterojunction.. See also Akiyama et al. fig. 41
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Akiyama et al. thereby demonstrates discloses the known concept of explicitly forming Si/Ge heterojunctions (¶[0004]3) between single crystal Si cells and Ge cells (e.g. 1B/2A interface), and demonstrates both single crystal Si and polycrystalline Ge are known materials for solar cell design and may be N or P type (¶[0002] ). As shown in the figure, even in a tandem solar cell electrodes 3&4 will be formed and electrically connected at opposing sides to complete the device.
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the method of Lin et al. to specifically form an N-type single crystal silicon layer and a P-type germanium-containing layer as suggested by the semiconductor configurations in Akiyama et al. The motivation for this modification would be to optimize the photoelectric conversion efficiency of the device by creating an additional functional P-N heterojunction at the interface of the substrate and the germanium-containing layer. A person of ordinary skill in the art would have recognized that while Lin et al. disclose the physical stacking of these layers, configuring them with opposite conductivity types, specifically N-type silicon and P-type germanium, is a known technique for forming tandem-style junctions as demonstrated by Akiyama et al.
Furthermore, it would have been a routine design choice for a person of ordinary skill in the art to interchange or select specific N-type or P-type dopants (e.g., selecting N-type for the silicon layer and P-type for the germanium layer) to achieve a desired carrier flow. The selection of specific conductivity types for a P-N junction is a matter of routine optimization among a limited number of known configurations to achieve the predictable result of a functioning heterojunction.
Such a modification represents the simple substitution of known doping parameters within a known vertical semiconductor architecture to obtain a predictable result. By utilizing the specific doping scheme taught in Akiyama et al. for the materials and method disclosed in Lin et al., the practitioner would achieve improved spectral response across a broader range of incident light wavelengths.
CLAIM 8. Lin et al. in view of Akiyama et al teaches the method for manufacturing a photodetection element according to claim 7, wherein in the second step, the layer including germanium is heated at a temperature of 500"C or higher for one hour or longer (Lin ¶[0014-15]).
CLAIM 10. Lin et al. in view of Akiyama et al teaches the method for manufacturing a photodetection element according to claim 8, wherein in the second step, the layer including germanium is heated for one hour or longer (Lin ¶[0014-15]).
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lin et al. (US 20130034950 A1) in view of Akiyama et al. (US 20090061557 A1).in view of Atwater et al. (J. Appl. Phys. 64, 2337–2353 (1988))
CLAIM 9. Lin et al. in view of Akiyama et al teaches method for manufacturing a photodetection element according to claim 8, wherein in the second step, the layer including germanium is heated at a temperature of 400-650'C. While Lin may be silent upon the temperature of 700'C or higher, it was well known in the art of semiconductor fabrication that increasing annealing temperatures promotes larger grain growth and reduces internal defects in polycrystalline layers.
The principle that grain size in polycrystalline semiconductors, such as Ge, increases as a function of annealing temperature is well established in the art. For example, Atwater characterizes the growth of grains in germanium and identifies that thermal annealing provides the necessary activation energy for grain boundary motion and grain growth. See Atwater page 2341 and figures 6 and 8, noting figure 6 explicitly discloses annealing Ge at 775C.
Therefore, it would have been obvious to a person of ordinary skill in the art to increase the temperature to 700C or higher as a matter of routine optimization to enhance the electrical conductivity and performance of the resulting photodetection element. The specific temperature is a result effective variable that one would naturally adjust to achieve a desired degree of crystallinity.
It would have been obvious to a PHOSITA of making semiconductor devices to determine the workable or optimal value for the annealing temperature through routine experimentation and optimization to obtain optimal or desired device performance because the temperature is a result-effective variable and there is no evidence indicating that it is critical or produces any unexpected results and it has been held that it is not inventive to discover the optimum or workable ranges of a result-effective variable within given prior art conditions by routine experimentation. See MPEP § 2144.05
Given the teaching of the references, it would have been obvious to determine the optimum thickness, temperature as well as condition of delivery of the layers involved. See In re Aller, Lacey and Hall (10 USPQ 233-237) “It is not inventive to discover optimum or workable ranges by routine experimentation.” Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the Applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Any differences in the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected. In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicants have the burden of explaining the data in any declaration they proffer as evidence of non-obviousness. Ex parte Ishizaka, 24 USPQ2d 1621, 1624 (Bd. Pat. App. & Inter. 1992).
An Affidavit or declaration under 37 CFR 1.132 must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JARRETT J STARK whose telephone number is (571)272-6005. The examiner can normally be reached 8-4 M-F.
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JARRETT J. STARK
Primary Examiner
Art Unit 2822
2/4/2026
/JARRETT J STARK/Primary Examiner, Art Unit 2898
1 Lin et al. - [0013] Step S1--deposition: Form an aluminum layer 11 and an amorphous germanium layer 12 on the P-type monocrystalline silicon substrate 10 in sequence. As shown in FIG. 1A, the aluminum layer 11 is interposed between the P-type monocrystalline silicon substrate 10 and the amorphous germanium layer 12. In one embodiment, the aluminum layer 11 and the amorphous germanium layer 12 are formed through a film deposition technology at a pressure of smaller than 1.times.10.sup.-5 mbar. In one embodiment, each of the aluminum layer 11 and the amorphous germanium layer 12 has a thickness of 500 nm.
2 Lin et al. - [[0014] Step S2--annealing: Anneal the P-type monocrystalline silicon substrate 10, the aluminum layer 11 and the amorphous germanium layer 12 at a temperature of 400-650.degree. C. for 0.5-6 hours.
[0015] Step S3--aluminum-induced crystallization: Undertake an aluminum-induced crystallization process in which the germanium atoms of the amorphous germanium layer 12 and the silicon atoms of the P-type monocrystalline silicon substrate 10 pass through the aluminum layer 11 (as shown in FIG. 1B), and then the amorphous germanium layer 12 is induced and converted into a P-type polycrystalline silicon-germanium layer 13 between the P-type monocrystalline silicon substrate 10 and the aluminum layer 11 (as shown in FIG. 1C).
3 Akiyama et al. - [0004] FIG. 1 is a cross-sectional schematic view used to explain the structure of a conventional tandem-structured photoelectric conversion element laminated with a silicon crystal cell and a germanium-based crystal cell. This element has a tandem structure in which a germanium-based crystal cell 2 for absorbing and photoelectrically converting light (hv.sub.1) having a band of wavelengths greater than 1.1 .mu.m and a silicon crystal cell 1 for absorbing and photoelectrically converting light (hv.sub.2) having a band of wavelengths equal to or less than 1.1 .mu.m are laminated. These cells are pn junction type cells in which layers (1A and 1B, and 2A and 2B) of mutually opposite conductivity types ("p" type and "n" type) are respectively laminated. A pn junction is also formed at a boundary face between the silicon crystal cell 1 and the germanium-based crystal cell 2.