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 Objections
Claim 17 objected to because of the following informalities:
Claim 17 ends in two periods however only a single period is allowed. Appropriate correction is required.
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.
Claim(s) 1-11, 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Murakami et al. (US 20220216026 A1) hereafter referred to as Murakami in view of Tang et al. (CN 109273554 A) hereafter referred to as Tang. For claim 11 Zarrine-Afsar et al. (US 20200144044 A1) hereafter referred to as Zarrine-Afsar is provided as evidence.
In regard to claim 1 Murakami teaches a Hot Electron Cathode [see Fig. 1, see paragraph 0033, 0047 “electrons are accelerated by the electric field in the h-BN12 and become hot electrons”, see also paragraph 0044 “Comparative Example 1, an electron emission device including a lower electrode 1 of a silicon semiconductor substrate, an insulating film 6 of SiO.sub.2, and an electron transmission electrode 3 of graphene or graphite was manufactured”] device comprising:
a semiconductor layer [see paragraph 0043 “lower semiconductor electrode of a silicon semiconductor substrate (n-Si)”];
a graphene monolayer [see paragraph 0035 “a single layer graphene film is more preferable” “In the case of a single layer of graphene, it is necessary to form a continuous film in order to emit electrons from the entire surface”] disposed over the semiconductor layer, the graphene monolayer configured as a gate [see paragraph 0043 “the lower semiconductor electrode (cathode) was grounded, a voltage was applied to the upper graphene electrode (gate) in a 0.1 V step from 0 V to approximately +20 V”] for the cathode device; and
an insulator layer [“a thin insulating film 6 functioning as an electron acceleration layer”, see both BN and SiO2 are disclosed] interposed between the semiconductor layer and graphene monolayer, the insulator layer allowing a voltage drop [see paragraph 0047 “An electric field is generated in the h-BN12 by the voltage applied between the upper metal electrode (the upper graphene electrode) and the lower semiconductor electrode”] between the semiconductor layer and graphene, wherein the cathode device is configured with an emitter surface [“electrons are accelerated by the electric field in the h-BN12 and become hot electrons” “At the time of reaching the interface between the upper graphene electrode 13 and vacuum 14, that is, the surface of the upper graphene electrode, all electrons have energy greater than the work function of the surface, so all electrons other than the electrons elastically scattered backward at the interface between the upper graphene electrode 13 and vacuum 14 are released into the vacuum 14”] and to emit hot electrons therefrom,
but does not teach Hot Electron Laser-Assisted Cathode (HELAC) and that the semiconductor layer that absorbs incident photons and that the cathode device is configured to receive photons on an emitter surface.
The Examiner notes that a person of ordinary skill in the art is aware that a LASER is a light source and stands for “Light Amplification by Stimulated Emission of Radiation” and is aware of how a laser works. Also see that claim 1 is a structure claim i.e. the laser is not part of the claimed device, the laser only produces the light absorbed by the device.
See Tang teaches light absorption in InGaAs, see Fig. 1 “a graphite alkenyl field indium gallium arsenic detector adopts indium phosphide as substrate material, on the substrate is grown on a layer of p-doped indium gallium arsenide material layer, an intrinsic layer of indium gallium arsenic material; a layer of n-doped indium gallium arsenide material layer, a layer silicon oxide medium layer, transferring or depositing a single-layer graphene on silicon oxide medium layer central region, two side growth source electrode and drain electrode of a single-layer graphene on the silicon oxide dielectric layer to grow back gate electrode under the indium phosphide substrate”, “said silicon oxide dielectric layer is 90 nm ~ 300 nm thick”, see Fig. 1 see that light comes from the top, passes through the graphene, and is absorbed in the InGaAs, see that layer 4 is n-type InGaAs is under the SiO2 layer 5, see “Single-layer graphene is has been found that thin, two-dimensional layered material because of its excellent high specific surface area, high carrier mobility, good mechanical property and other physical and chemical characteristics, and the optoelectronic device, an optical composite material, sensor and other fields to be widely used”.
Thus it can be seen that like Murakami even in the device of Tang the substrate is biased, however in Tang hole-electron pairs are created by absorption in InGaAs by light entering from above and passing through the graphene of Tang.
Thus, it 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 to modify Murakami to include Hot Electron Laser-Assisted Cathode (HELAC) and that the semiconductor layer that absorbs incident photons and that the cathode device is configured to receive photons on an emitter surface.
Thus it would be obvious to combine the references to arrive at the claimed invention.
The motivation is to use a light source such as the well known laser to control the device of Murakami, at the speed of a laser light and because light absorption is a known to be a good way to create hole-electron pairs which can separate in an electric field to provide charge carriers as needed and that semiconductor layers are useful for band gap control in the device for absorption of light and separation of charges.
In regard to claim 2 Murakami and Tang as combined teaches in electrical communication with a power supply for positively biasing [see Murakami paragraph 0043 “the lower semiconductor electrode (cathode) was grounded, a voltage was applied to the upper graphene electrode (gate) in a 0.1 V step from 0 V to approximately +20 V”] the graphene monolayer relative to the semiconductor layer.
In regard to claim 3 Murakami and Tang as combined teaches wherein the semiconductor layer is deposited [see combination, see Tang Fig. 1 see layers 2, 3, 4 on substrate 1] over a wafer substrate.
In regard to claim 4 Murakami and Tang as combined teaches wherein the wafer substrate is a indium phosphide (InP) wafer [see combination, see Tang “a graphite alkenyl field indium gallium arsenic detector adopts indium phosphide as substrate material, on the substrate is grown on a layer of p-doped indium gallium arsenide material layer ...”] but does not state p-doped.
However see that layer 2 in Tang Fig. 1 is p-type and see the “back gate electrode 9”, thus having substrate as p-type would give good conduction.
Thus, it 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 to modify Murakami to include the wafer substrate is p-doped.
Thus it would be obvious to combine the references to arrive at the claimed invention.
The motivation is to obtain good conduction.
In regard to claim 5 Murakami and Tang as combined teaches wherein the semiconductor layer is [see combination, see Tang Fig. 1 see layers 2, 3, 4 are InGaAs] an indium gallium arsenide layer.
In regard to claim 6 Murakami and Tang as combined teaches wherein the indium gallium arsenide layer has a thickness [see combination, see Tang “thickness is 0.95 to μ, Zn-doped concentration is 4 * 1018 cm (3) of p-doped indium gallium arsenic (InGaAs) layer 2, 2) is an intrinsic indium gallium arsenic material layer of 1.5 μ m 3, 3) has a thickness of 1 μ m, Si-doped concentration is 2 * 1018 cm (3) of n-doped InGaAs material layer 4”] from about 0.25 to 3 microns.
In regard to claim 7 Murakami and Tang as combined teaches wherein the insulator layer has a thickness [see Murakami teaches two embodiments with materials BN and SiO2, see for BN “film thickness of about 4 nm or more and 20 nm or less is preferable because the electron emission efficiency increases” however for SiO2 Murakami states “As Comparative Example 1, an electron emission device including a lower electrode 1 of a silicon semiconductor substrate, an insulating film 6 of SiO.sub.2” and “optimization of the SiO.sub.2 film thickness or the like was performed”] from about 5to15 nm.
In regard to claim 8 Murakami and Tang as combined teaches wherein the insulator layer is composed of a dielectric selected from the group consisting [see Murakami teaches two embodiments with materials BN and SiO2, “As Comparative Example 1, an electron emission device including a lower electrode 1 of a silicon semiconductor substrate, an insulating film 6 of SiO.sub.2” ] of SiO2, Si3N4, HfO2, and Al2O3.
In regard to claim 9 Murakami and Tang as combined teaches [see combination, see Tang “short wave infrared (1~3 μ m)” “the short wave infrared detection field, indium gallium arsenic (InGaAs) infrared detector”] wherein the semiconductor layer absorbs photons at or near 1550 nm.
In regard to claim 10 Murakami and Tang as combined teaches [see Murakami paragraph 0043 “the lower semiconductor electrode (cathode) was grounded, a voltage was applied to the upper graphene electrode (gate) in a 0.1 V step from 0 V to approximately +20 V, +1000 V was applied to the SUS plate (anode) opposing the electron emission device, and the current flowing in the lower semiconductor electrode, the upper graphene electrode, and the SUS plate was measured. From the measurement results, it was confirmed that electron emission started from an applied voltage of 13 V, and that the emission current increased as the applied voltage increased. It was confirmed that the emission current density reached 2 A/cm2 at an applied voltage of 55 V, and that a sufficient emission current was obtained”] wherein current density is from ~1 mA/cm2 to 1 A/cm2.
In regard to claim 11 Murakami and Tang as combined does not specifically teach wherein the HELAC device can be modulated at rates from 10-250 GHz.
However see that the hole-electrons are created by laser and swept away by tunneling, thus the issue is only the speed of turn-on/turn-off of the laser.
See evidence Zarrine-Afsar, a person of ordinary skill in the art is aware that lasers can operate in the pico-second range, seeAbstract “laser is provided having a pulse range of about 1-1000 picoseconds” “the method may comprise using pico-second infrared laser ablation or desorption” .
It 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 to use “wherein the HELAC device can be modulated at rates from 10-250 GHz ”, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233
In regard to claim 17 Murakami and Tang as combined teaches wherein photo-excited electrons are swept to [see combination, see Murakami “a thin insulating film 6 functioning as an electron acceleration layer”] an insulator-graphene interface, tunnel through [because of the acceleration] the insulator layer, and are emitted from the graphene monolayer into vacuum [“electrons are accelerated by the electric field in the h-BN12 and become hot electrons” “At the time of reaching the interface between the upper graphene electrode 13 and vacuum 14, that is, the surface of the upper graphene electrode, all electrons have energy greater than the work function of the surface, so all electrons other than the electrons elastically scattered backward at the interface between the upper graphene electrode 13 and vacuum 14 are released into the vacuum 14”] when a positive bias is applied to the [see Murakami paragraph 0043 “the lower semiconductor electrode (cathode) was grounded, a voltage was applied to the upper graphene electrode (gate) in a 0.1 V step from 0 V to approximately +20 V”] graphene monolayer relative to the semiconductor layer.
Claim(s) 12, 14-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Murakami et al. (US 20220216026 A1) hereafter referred to as Murakami in view of Tang et al. (CN 109273554 A) hereafter referred to as Tang.
In regard to claim 12 Murakami teaches a method for fabricating a Hot Electron Cathode device [see Fig. 1, see paragraph 0033, 0047 “electrons are accelerated by the electric field in the h-BN12 and become hot electrons”, see also paragraph 0044 “Comparative Example 1, an electron emission device including a lower electrode 1 of a silicon semiconductor substrate, an insulating film 6 of SiO.sub.2, and an electron transmission electrode 3 of graphene or graphite was manufactured”] comprising:
a semiconductor layer [see paragraph 0043 “lower semiconductor electrode of a silicon semiconductor substrate (n-Si)”];
depositing an insulator layer [“a thin insulating film 6 functioning as an electron acceleration layer”, see both BN and SiO2 are disclosed, see paragraph 0039 “a CVD method using ammonia borane (H.sub.6NB), borazine (B.sub.3N.sub.3H.sub.6), or diborane (B.sub.2H.sub.6) and ammonia (NH.sub.3) as source gas materials, and the like”] over the semiconductor layer by chemical vapor deposition;
forming a graphene layer [see paragraph 0035 “a single layer graphene film is more preferable” “In the case of a single layer of graphene, it is necessary to form a continuous film in order to emit electrons from the entire surface” see paragraph 0041 “Subsequently, a graphene or graphite surface electrode is formed on the surface of the boron nitride film”] on the insulator layer
but does not specifically teach Hot Electron Laser-Assisted Cathode (HELAC) and
epitaxially depositing a semiconductor layer over a top face of a wafer substrate;
depositing an insulator layer over the semiconductor layer by atomic layer deposition and/or plasma-enhanced chemical vapor deposition;
depositing a bottom contact over a bottom face of the wafer substrate; and
transferring a graphene layer onto the insulator layer
The Examiner notes that a person of ordinary skill in the art is aware that a LASER is a light source and stands for “Light Amplification by Stimulated Emission of Radiation” and is aware of how a laser works.
See also the claim 12 is method of fabricating the device, i.e. the laser is not part of the claimed device, the laser only produces the light absorbed by the device.
See Tang teaches light absorption in InGaAs, see Fig. 1 “a graphite alkenyl field indium gallium arsenic detector adopts indium phosphide as substrate material, on the substrate is grown on a layer of p-doped indium gallium arsenide material layer, an intrinsic layer of indium gallium arsenic material; a layer of n-doped indium gallium arsenide material layer, a layer silicon oxide medium layer, transferring or depositing a single-layer graphene on silicon oxide medium layer central region, two side growth source electrode and drain electrode of a single-layer graphene on the silicon oxide dielectric layer to grow back gate electrode under the indium phosphide substrate”, “said silicon oxide dielectric layer is 90 nm ~ 300 nm thick”, see Fig. 1 see that light comes from the top, passes through the graphene, and is absorbed in the InGaAs, see that layer 4 is n-type InGaAs is under the SiO2 layer 5, see “Single-layer graphene is has been found that thin, two-dimensional layered material because of its excellent high specific surface area, high carrier mobility, good mechanical property and other physical and chemical characteristics, and the optoelectronic device, an optical composite material, sensor and other fields to be widely used”.
See in Tang:
the substrate “firstly, using indium phosphide as substrate material, and cleaning the substrate, indium phosphide (InP) substrate 1 material”,
see growing epitaxial layers “then using metal organic chemical vapor deposition (MOCVD) technique on the indium phosphide substrate 1 orderly growing 1) thickness is 0.95 to μ, Zn-doped concentration is 4 * 1018 cm (3) of p-doped indium gallium arsenic (InGaAs) layer 2, 2) is an intrinsic indium gallium arsenic material layer of 1.5 μ m 3, 3) has a thickness of 1 μ m, Si-doped concentration is 2 * 1018 cm (3) of n-doped InGaAs material layer 4” under broadest reasonable interpretation, MOCVD is epitaxial growth,
see depositing insulator “after that, using the plasma enhanced chemical vapor deposition (PECVD) technique the deposition thickness 90 nm of the SiO2 dielectric layer 5”
see transferring graphene “then using dry transfer technology, the single-layer graphene 6 transfer to SiO2 medium layer 5”
see depositing metal electrodes “finally depositing a metal electrode, depositing a source electrode 7 and drain electrode 8, lower central deposition on indium phosphide substrate 1 back gate electrode 9 by the ion beam sputtering technology to deposit metal electrode, the vacuum degree is 2~5 * 10-2Pa, the ion beam energy is 80eV to 250eV on the SiO2 dielectric layer 5 on a single-layer graphene 6 two side”.
Thus it can be seen that like Murakami even in the device of Tang the substrate is biased, however in Tang hole-electron pairs are created by absorption in InGaAs by light entering from above and passing through the graphene of Tang.
Thus, it 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 to modify Murakami to include Hot Electron Laser-Assisted Cathode (HELAC) and epitaxially depositing a semiconductor layer over a top face of a wafer substrate; depositing an insulator layer over the semiconductor layer by atomic layer deposition and/or plasma-enhanced chemical vapor deposition; depositing a bottom contact over a bottom face of the wafer substrate; and transferring a graphene layer onto the insulator layer.
Thus it would be obvious to combine the references to arrive at the claimed invention.
The motivation is to use a light source such as the well known laser to control the device of Murakami, at the speed of a laser light and because light absorption is a known to be a good way to create hole-electron pairs which can separate in an electric field to provide charge carriers as needed and that semiconductor layers are useful for band gap control in the device for absorption of light and separation of charges, and using epitaxial growth is for obtaining good crystal, PECVD is a common technique known to give good results for growth, contacts are useful to make connection to the device to pass electricity, transferring graphene for ease of growth of good quality graphene for good electrical response.
In regard to claim 14 Murakami and Tang as combined teaches wherein the graphene layer is [see Murakami paragraph 0035 “a single layer graphene film is more preferable” “In the case of a single layer of graphene, it is necessary to form a continuous film in order to emit electrons from the entire surface”, see combination Tang, “then using dry transfer technology, the single-layer graphene 6 transfer to SiO2 medium layer 5”] a graphene monolayer.
In regard to claim 15 Murakami and Tang as combined teaches [see combination, see Tang “a graphite alkenyl field indium gallium arsenic detector adopts indium phosphide as substrate material, on the substrate is grown on a layer of p-doped indium gallium arsenide material layer ...”] wherein the wafer substrate is an InP wafer.
In regard to claim 16 Murakami and Tang as combined teaches wherein the insulator layer is composed of a dielectric selected from the group consisting [see Murakami teaches two embodiments with materials BN and SiO2, “As Comparative Example 1, an electron emission device including a lower electrode 1 of a silicon semiconductor substrate, an insulating film 6 of SiO.sub.2” ] of SiO2, Si3N4, HfO2, and Al2O3.
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Murakami and Tang as combined and further in view of Kuroiwa et al. (WO 2006112455 A1) hereafter referred to as Kuroiwa
In regard to claim 13 Murakami and Tang as combined teaches further comprising depositing a [see Murakami “contact electrode 4”, see combination Tang depositing electrodes] top contact over the graphene layer but does not state mesh.
However see Murakami Fig. 1 see that “contact electrode 4” is on “thick insulating film 2 defining an electron emitting surface 5”, thus if 2 is a window defining an emitting surface, it has a window or grid shape.
See Kuroiwa “the positive electrode 25 is a grid-like metal mesh electrode”.
Thus, it 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 to modify Murakami to include mesh top contact.
Thus it would be obvious to combine the references to arrive at the claimed invention.
The motivation is that a mesh electrode shape combines good contact and field distribution with enough holes for good emission.
Response to Arguments
Applicant's arguments filed 9/29/2025 have been fully considered but they are not persuasive.
On page 1 the Applicant argues “The Examiner has fundamentally mischaracterized the claimed invention and improperly combined non-analogous art to arrive at the rejection. Murakami discloses a laminated semiconductor/insulator/graphene emission stack pursued to achieve narrow energy width for electron microscopes. This reference neither uses a telecom absorber nor relies on photon-driven hot-electron emission from the illuminated surface as claimed. In contrast, Tang is a graphene/InGaAs photodetector that collects photocarriers within the device and does not emit electrons into vacuum”.
The Examiner responds the invention is a device and method of manufacturing a device and that the structural limitations of the claims were shown obvious in view of the prior art.
On page 1, 2 the Applicant argues “First, Murakami and Tang are non-analogous art that address entirely different problems in unrelated fields. Murakami is directed to electron emission devices for electron microscopes that require extremely narrow electron energy widths (100-600 meV) achieved through purely electrical means: An electric field is generated in the h-BN12 by the voltage applied between the upper metal electrode (the upper graphene electrode) and the lower semiconductor electrode. This electric field causes electrons to flow from the lower semiconductor electrode 11 into the h-BN12 due to the tunneling phenomenon. Murakami, paragraph [0047] The entire Murakami reference contains no mention of photons, light, laser, optical, illumination, or photo-generation. The Office Action appears to concede this point by admitting that Murakami " does not teach Hot Electron Laser-Assisted Cathode (HELAC) and that the semiconductor layer that absorbs incident photons and that the cathode device is configured to receive photons on an emitter surface." The Office Action alleges that Tang remedies this deficiency. While the Examiner correctly notes that Tang teaches light absorption in InGaAs, Tang uses this absorption for photodetection by measuring lateral current flow between source and drain electrodes. This is fundamentally different from the claimed HELAC device, which uses photo-generated carriers for electron emission into vacuum. Tang provides no teaching or suggestion to emit electrons from its structure. In fact, Tang's entire purpose is to keep carriers within the device for measurement, not emit them. One skilled in the art would not look to a photodetector that retains carriers to create an electron emitter that releases carriers. Neither Muraki nor Tang is directed to the field of photo-assisted electron emission for high-frequency modulation applications, which is the problem addressed by the claimed HELAC device. A person of ordinary skill in the art seeking to develop a photo-assisted cathode capable of ultrafast modulation would not look to combine an electron microscope source with a photodetector, as these devices operate on fundamentally different principles and serve incompatible purposes”.
The Examiner responds that secondary reference simply shows absorption of light to generate photogenerated carriers and this is true about semiconductors in general and should be known to any person of ordinary skill in the art, and the interaction of light with semiconductor is a fundamental property that is explained by hundreds of thousands of patent prior art of which Tang is only one, thus the Examiner cannot agree that description of a fundamental property of semiconductor is not relevant to all semiconductor including the primary reference Murakami and the Examiner cannot accept that the Applicants invention is novel because it uses light absorption in semiconductor, this is not novel and is known in the art.
On page 2, 3 the Applicant argues “Second, the proposed combination fails to teach or suggest critical elements of claim 1, particularly that the device is "configured to receive photons on an emitter surface and to emit hot electrons therefrom." Murakami's device operates through purely electrical tunneling without any photon involvement in which electrons tunnel from the semiconductor through the insulator and graphene based solely on applied voltage. Tang's device detects photons but measures lateral current flow between source and drain electrodes, not electron emission into vacuum. The Examiner provides no explanation for how combining these references would result in a device where photo-generated carriers are emitted as hot electrons from the graphene surface into vacuum, which is the fundamental operating principle of the claimed HELAC device”.
The Examiner responds that the secondary reference teaches photogenerated carriers by absorption of light and that the electrical behaviour of these carriers in the device of Murakami is taught by Murakami.
On page 3, 4 the Applicant argues “Third, the proposed combination would destroy the intended purpose of Murakami's device and render it inoperable. Murakami explicitly teaches that its device achieves narrow energy width by minimizing electron scattering, stating that "inelastic scattering of electrons does not occur" (Murakami, 47-48). The entire design philosophy of Murakami centers on using h-BN and graphene specifically to suppress electron scattering to maintain the narrow energy distribution. In order to suppress the scattering of electrons at the electron transmission electrode as much as possible, a single layer graphene film is more preferable. Murakami, paragraph [0035] The elements constituting the insulating layer of h-BN are B and N, and the atomic numbers of the constituent elements are smaller than those of conventional SiO2 and A1203. Since the inelastic scattering cross-sectional area of electrons is generally proportional to the atomic number, the inelastic scattering of electrons in the electron accelerating layer is suppressed by using h-BN as the insulating material of the electron accelerating layer. Therefore, the energy distribution 22 of the electrons accelerated by h-BN and reaching the upper graphene electrode 13 becomes the same as the energy distribution 21 of the electrons immediately after tunneling through the lower semiconductor electrode 11. Furthermore, in the upper graphene electrode, the element constituting the electrode is C, and the atomic number is small compared to the conventionally used elements (Al, Au, Pt, and the like) of the upper metal electrode material, so it is possible to suppress inelastic scattering of electrons in the upper graphene electrode. Murakami, paragraph [0047] Introducing photo-generation as suggested by the Examiner would introduce additional scattering mechanisms and carrier interactions that would destroy the narrow energy distribution that is Murakami's primary objective. One of ordinary skill would recognize this fundamental incompatibility and would not be motivated to combine the references.”
The Examiner responds that the secondary reference teaches photogenerated carriers by absorption of light and the Examiner notes that a laser has a known energy and the bandgap of the semiconductor is known and so is the doping and electric field and other design parameters, and that basics of semiconductors such as Fermi-Dirac statistics, density of staes etc are well known to a person of ordinary skill in the art and that the electrical behaviour of these carriers in the device of Murakami is taught by Murakami and that a person of ordinary skill in the art is very much capable of applying the teachings of Tang to Murakami and can make the device function normally to emit electrons as desired.
On page 4, 5 the Applicant argues “Fourth, the Examiner's stated motivation to combine Murakami and Tang as being "to use a light source such as the well-known laser to control the device" is conclusory and finds no support in either reference. Neither Murakami nor Tang provides any teaching, suggestion, or motivation to convert Murakami's purely electrical emission device into a photo-assisted one, to use Tang's photodetector structure for electron emission rather than detection, or to achieve the specific claimed configuration where incident photons generate hot electrons that are emitted from the graphene surface. The Examiner's reasoning appears to rely on impermissible hindsight reconstruction using Applicant's own disclosure”.
The Examiner responds that that this is a fact, because light absorption in semiconductor creates photogenerated carries and alters i.e. controls the device behavior, thus the Applicants argument is not based on fact.
On page 5 the Applicant argues “Finally, the specification demonstrates that the claimed HELAC device achieves unexpected results that further distinguish it from any combination of the cited art. The HELAC achieves quantum efficiency greater than 30%, compared to less than 0.05% for previous photo- gated emitters, while enabling modulation rates up to 250 GHz and current densities up to 1 A/cm2. (Specification, paragraphs [0006], [0010], and [0011]). These remarkable improvements are not predictable from combining an electron microscope source designed for narrow energy width with a photodetector designed to measure infrared radiation. The claimed invention represents a distinct breakthrough in photo-assisted electron emission technology that solves long-standing problems in high-frequency vacuum electronics. Zarrine-Afsar is irrelevant to the deficiencies of Murakami and Tang. The Examiner merely relies on this reference for "laser [being] provided having a pulse range of about 1-1000.”
The Examiner responds the invention is a device and method of manufacturing a device and that the structural limitations of the claims were shown obvious in view of the prior art and that the results are based on the physical properties of the device and thus there is nothing unexpected in the results.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SITARAMARAO S YECHURI whose telephone number is (571)272-8764. The examiner can normally be reached M-F 8:00-4:30 PM.
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/SITARAMARAO S YECHURI/ Primary Examiner, Art Unit 2893