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 .
Response to Amendment
This Office Action is in response to Applicant's amendments filed July 25, 2025. Claims 1-2, 4, 6, and 19-20 have been amended. Claim 21 has been added. Claims 3 and 18 have been canceled. Claims 10-17 stand withdrawn. Currently, claims 1-2, 4-9, and 19-21 are pending.
Applicant’s cancellation of claim 18 and amendments to claim 20 overcome the 112(a) rejection outlined in the previous Office Action. The 112(a) rejection of claims 18 and 20 has been withdrawn.
Applicant’s amendment to claim 6 overcomes the 112(b) rejection outlined in the previous Office Action. The 112(b) rejection of claim 6 has been withdrawn.
Response to Arguments
Applicant's arguments filed July 25, 2025 have been fully considered but they are not persuasive.
The Applicant asserts that the combination of An and Kim fails to disclose the limitations of newly amended claim 1, which were presented in original claim 3. Specifically, that An “discloses the MOS structure and the Schottky junction structure, but does not mention anything about the components of the insulating layer that increase the photocurrent for improving photo-responsiveness and detectivity” and Kim discloses “the optical sensor completely different from the cited reference An, but the purpose of configuring the ion gel layer to function as a gate insulating layer is to obtain the effect of enabling gating operation with a less electrical field due to the high dielectric constant of the ion gel, that is, the effect of lowering the operating voltage of the optical sensor”. The Applicant asserts that since neither reference considers the advantage of “photo-responsiveness and detectability of the photodiode are improved as a photocurrent increases due to a high electric capacitance of the ion gel” the combination fails to render obvious the limitations of newly amended claim 1.
The Examiner respectfully disagrees with these assertions. Firstly, the fact that the structure of Kim is different from that of An does not mean that one of ordinary skill in the art would not consider combining the references as proposed by the previous Office Action. An and Kim are in the closely related fields of optoelectronic devices and optical sensors. Therefore, one of ordinary skill in the art could easily identify benefits or advantages of a material in one as applying to the device of the other. Kim discloses that the use of ion gel in the dielectric layer of the optical sensor provides favorable dielectric and mechanical properties (see Kim, ¶ [0054]), which would also be favorable in the optoelectronic device of An, motivating one of ordinary skill in the art to combine the references as proposed by the previous Office Action.
Furthermore, in response to applicant's argument that the prior art does not consider the advantages of the claimed structure, specifically improved photo-responsiveness and detectability, 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).
Therefore, the previous rejection of claims 1 and 19 in view of An and Kim is maintained as appropriate and presented in full herein.
However, the Examiner concedes that the combination of An and Kim failed to disclose the limitations of claim 8 as applied in the previous Office Action. Therefore, the rejection of claim 8 has been withdrawn. Upon further consideration, a new grounds of rejection is made in view of An et al. (“Tunable Graphene–Silicon Heterojunctions for Ultrasensitive Photodetection”, pub. 02/05/2013) in view of Kim et al. (US 20180138231 A1) and Frisbie et al. (US 7999020 B2).
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.
Claims 1-2, 7, 9, and 19-21 are rejected under 35 U.S.C. 103 as being unpatentable over An et al. (“Tunable Graphene–Silicon Heterojunctions for Ultrasensitive Photodetection”, pub 02/05/2013) hereinafter “An” in view of Kim et al. (US 20180138231 A1) hereinafter “Kim”.
Regarding claim 1, Fig. 1(a) of An discloses a photodiode (Fig. 1(a), “monolayer graphene (1LG)/Si heterojunction device”, page 910, Fig. 1 caption) comprising:
a semiconductor substrate (Fig. 1(a), Silicon (lightly n doped));
an insulating layer (Fig. 1(a), SiO2 layer) on the semiconductor substrate (Silicon) to cover a portion of the semiconductor substrate (Silicon) (the SiO2 layer covers a portion of the silicon layer below it);
at least one electrode (Fig. 1(a), Au/Ti layer) on the insulating layer (SiO2 layer) to cover a portion of the insulating layer (SiO2 layer) (the Au/Ti layer covers a portion of the SiO2 layer below it); and
a graphene layer (Fig. 1(a), Graphene) on the semiconductor substrate (Silicon), the insulating layer (SiO2 layer), and the at least one electrode (Au/Ti layer) to cover a portion of the at least one electrode (AU/Ti layer), an exposed portion of the insulating layer (SiO2 layer) that is not covered by the electrode (Au/Ti layer), and an exposed portion of the semiconductor substrate (Silicon) that is not covered by the insulating layer (SiO2 layer) (the graphene layer covers the exposed portions of each layer that are not covered by the layer directly on top of each respectively layer).
An does not teach that the insulating layer comprises an ion gel.
In the similar field of endeavor of optical sensors, Fig. 2 of Kim discloses that the insulating layer comprises an ion gel (Fig. 2, "a dielectric layer (e.g., an ion gel layer) 50", ¶ [0039]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the dielectric layer including an ion gel as disclosed by Kim, to obtain the desired dielectric and physical properties (see Kim, ¶ [0054]) and/or because the use of conventional materials to perform their known function is prima-facie obvious (MPEP 2144.07).
Regarding claim 2, An and Kim together disclose the photodiode of claim 1 as applied above, and Fig. 1(a) of An further discloses that the graphene layer (Graphene) is formed to extend on the semiconductor substrate (Silicon), the insulating layer (SiO2 layer), and the electrode (Au/Ti layer) (the graphene layer extends on the silicon, SiO2, and Au/Ti layers).
Regarding claim 7, An and Kim together disclose the photodiode of claim 1 as provided above, but An does not teach that the ion gel comprises a block copolymer including at least one selected from a group comprising Polyethylene oxide (PEO), Polystyrene (PS), Polycaprolactone (PCL), Polyacrylonitrile (PAN), Polymethyl methacrylate (PMMA), Polyimide, and Polyvinylidene fluoride (PVDF) Polyvinylchloride (PVC).
In the similar field of endeavor of optical sensors, Fig. 2 of Kim discloses the ion gel comprises a block copolymer (“The polymer binder may include a block copolymer”, ¶ [0053]) including at least one selected from a group comprising Polyethylene oxide (PEO), Polystyrene (PS), Polycaprolactone (PCL), Polyacrylonitrile (PAN), Polymethyl methacrylate (PMMA), Polyimide, and Polyvinylidene fluoride (PVDF) Polyvinylchloride (PVC) ("polymer binder, any one of, for example, poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)), poly(styrene-block-ethylene oxide-block-styrene) (PSPEOPS), and poly(styrene-block-methylmethacrylate-block-styrene) (PSPMMAPS) may be applied", ¶ [0053]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the ion gel as disclosed by Kim, to obtain the desired dielectric and physical properties (see Kim, ¶ [0054]) and/or because the use of conventional materials to perform their known function is prima-facie obvious (MPEP 2144.07).
Regarding claim 9, An and Kim together disclose the photodiode of claim 1 as applied above, and Fig. 1(a) of An further discloses a photodetector comprising the photodiode of claim 1 (“graphene/Si heterojunctions can be used for a variety of tunable optoelectronic devices… makes them versatile and highly sensitive photodetectors for a variety of imaging, metrology, and analytical applications”, page 915, col. 1, lines 8-9 and 17-19).
Regarding claim 19, Fig. 1(a) of An discloses a photodiode (Fig. 1(a)) comprising:
a semiconductor substrate (Silicon);
an insulating layer (SiO2 layer) on the semiconductor substrate (Silicon) to cover a portion of the semiconductor substrate (Silicon) (the SiO2 layer covers a portion of the silicon layer below it); and
a graphene layer (Graphene) extending continuously on the semiconductor substrate (Silicon) and the insulating layer (SiO2 layer) to cover the insulating layer (SiO2) and an exposed portion of the semiconductor substrate (Silicon) that is not covered by the insulating layer (SiO2) (the graphene layer covers the exposed portions of the SiO2 and the Silicon that are not covered by the layer directly on top).
An does not teach that the insulating layer comprises an ion gel.
In the similar field of endeavor of optical sensors, Fig. 2 of Kim discloses that the insulating layer comprises an ion gel (Fig. 2, "a dielectric layer (e.g., an ion gel layer) 50", ¶ [0039]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the dielectric layer including an ion gel as disclosed by Kim, to obtain the desired dielectric and physical properties (see Kim, ¶ [0054]) and/or because the use of conventional materials to perform their known function is prima-facie obvious (MPEP 2144.07).
Regarding claim 20, An and Kim together disclose the photodiode of claim 19 as applied above, and Fig. 1(a) of An further discloses an electrode (Au/Ti layer) on the insulating layer (SiO2 layer),
wherein the graphene layer (Graphene) extends continuously from the insulating layer (SiO2 layer) to the electrode (Au/Ti layer) to cover a portion of the at least one electrode (Au/Ti layer), an exposed portion of the insulating layer (SiO2) that is not covered by the at least one electrode (Au/Ti layer), and an exposed portion of the semiconductor substrate (Silicon) that is not covered by the insulating layer (SiO2) (the graphene layer covers the exposed portions of each layer that are not covered by the layer directly on top of each respectively layer).
Regarding claim 21, An and Kim together disclose the photodiode of claim 1 as applied above, and Fig. 1(a) of An further discloses wherein the insulating layer (SiO2) is interposed between the graphene layer (Graphene) and semiconductor substrate (Silicon).
An does not teach that the insulating layer comprises an ion gel.
In the similar field of endeavor of optical sensors, Fig. 2 of Kim discloses that the insulating layer comprises an ion gel (Fig. 2, "a dielectric layer (e.g., an ion gel layer) 50", ¶ [0039]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the dielectric layer including an ion gel as disclosed by Kim, to obtain the desired dielectric and physical properties (see Kim, ¶ [0054]) and/or because the use of conventional materials to perform their known function is prima-facie obvious (MPEP 2144.07).
Claims 4, 5, and 6 are rejected under 35 U.S.C. 103 as being unpatentable over An (“Tunable Graphene–Silicon Heterojunctions for Ultrasensitive Photodetection”) and Kim (US 20180138231 A1), and further in view of Di Bartolomeo et al. (“Graphene–Silicon Schottky Diodes for Photodetection”, pub 07/09/2018, hereinafter “Bartolomeo”).
Regarding claim 4, An and Kim together disclose the photodiode of claim 1 as applied above, but the combination fails to disclose a thickness of a first area of the semiconductor substrate covered by the insulating layer is smaller than a thickness of a second area of the semiconductor substrate not covered by the insulating layer.
In the similar field of endeavor of graphene/silicon Schottky junctions, Fig. 2b of Bartolomeo discloses a thickness of a first area (Fig. 2b, flat regions of the Si substrate) of the semiconductor substrate (Fig. 2b, n-Si layer) covered by the insulating layer (Fig. 2b, SiO2 layer) is smaller than a thickness of a second area (Fig. 2b, pointed triangle regions of Si substrate) of the semiconductor substrate (n-Si layer) not covered by the insulating layer (SiO2 layer) (the silicon substrate in the pointed regions that isn't covered by the SiO2 layer is thicker than the silicon substrate in the flat regions covered by the SiO2 layer).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the varying thickness as disclosed by Bartolomeo, to obtain the desired light absorption properties (see Bartolomeo, page 1136, section V, results and discussion section of the paper, right column, benefits 1-3).
Regarding claim 5, An, Kim and Bartolomeo together disclose the photodiode of claim 4 as applied above, but An and Kim fail to disclose the thickness of the second area is the same as a sum of the thickness of the first area and a thickness of the insulating layer.
In the similar field of endeavor of graphene/silicon Schottky junctions, Fig. 2b of Bartolomeo discloses the thickness of the second area (pointed triangle regions) is the same as a sum of the thickness of the first area (flat regions of the Si substrate) and a thickness of the insulating layer (SiO2 layer) (the thickness of the SiO2 layer + the thickness of the flat regions of the substrate = the thickness of the top most point of the pointed triangle regions).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the varying thickness as disclosed by Bartolomeo, to obtain the desired light absorption properties (see Bartolomeo, page 1136, section V, results and discussion section of the paper, right column, benefits 1-3).
Regarding claim 6, An, Kim and Bartolomeo together disclose the photodiode of claim 5 as applied above, and Fig. 1(a) of An further discloses:
the insulating layer (SiO2 layer) is formed to be spaced apart from each other on the semiconductor substrate (Silicon) (the two insulating SiO2 layer regions are spaced apart from one another on the substrate),
wherein, when the at least one electrode (Au/Ti) comprises a plurality of electrodes (Au/Ti), the plurality of electrodes (Au/Ti) are respectively formed on the insulating layer (SiO2) formed to be spaced apart from each other (the at least one electrode comprises the top Au/Ti layer and the bottom Au/Ti layer which are on the top and bottom of the insulating layer), and
wherein the graphene layer (Graphene) is formed to extend on the semiconductor substrate (Silicon), the insulating layer (SiO2) formed to be spaced apart from each other (the two insulating SiO2 layer regions are spaced apart from one another on the substrate), and the at least one electrode (Au/Ti layer) that is formed on the insulating layer (SiO2) formed to be spaced apart from each other (the graphene layer extends on the top portion of the Au/Ti layer).
An and Bartolomeo do not teach that the insulating layer comprises an ion gel.
In the similar field of endeavor of optical sensors, Fig. 2 of Kim discloses that the insulating layer comprises an ion gel (Fig. 2, "a dielectric layer (e.g., an ion gel layer) 50", ¶ [0039]).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the dielectric layer including an ion gel as disclosed by Kim, to obtain the desired dielectric and physical properties (see Kim, ¶ [0054]) and/or because the use of conventional materials to perform their known function is prima-facie obvious (MPEP 2144.07).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over An (“Tunable Graphene–Silicon Heterojunctions for Ultrasensitive Photodetection”) and Kim (US 20180138231 A1), and further in view of Frisbie et al. (US 7999020 B2) herein after “Frisbie”.
Regarding claim 8, An and Kim together disclose the photodiode of claim 7 as applied above, and Kim further discloses the use of 1-ethyl-3methylimidazolium based ionic liquids (see Kim, ¶ [0052]), however An and Kim fail to explicitly disclose the ion gel comprises at least one selected from a group comprising:
1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide([EMIM][TFSI]),
1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), and
1-ethyl-3-methylimidazolium n-octylsulfate ([EMIM][OctOSO3]).
In the similar field of endeavor of insulating materials for semiconductor devices, Fig. 6 of Frisbie discloses the ion gel comprises at least one selected from a group comprising:
1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide([EMIM][TFSI]),
1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), and
1-ethyl-3-methylimidazolium n-octylsulfate ([EMIM][OctOSO3]) (“the ionic liquid is selected from the group consisting of [BMIM][PF.sub.6], [EMIM][TFSI]”, col. 2, lines 48-49).
It would have been obvious to one of ordinary skill in the art before the time of the effective filling date of the invention to modify the photodiode of An with the ion gel as disclosed by Frisbie, to obtain the desired dielectric properties (see Frisbie, col. 11, lines 37-38) and/or because the use of conventional materials to perform their known function is prima-facie obvious (MPEP 2144.07).
Conclusion
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/C.A.N./ Examiner, Art Unit 2893
/YARA B GREEN/ Supervisor Patent Examiner, Art Unit 2893
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