Optical Sensor Device

Abstract

To provide an optical sensor device that has both weatherability and sensitivity.SOLUTION: An optical sensor device has: a substrate; a graphene layer provided on the substrate; a pair of electrodes connected to the graphene layer; and a resin layer which covers a light reception region of the graphene layer, and is transparent to light to be detected.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to optical sensor devices. [Background technology]

[0002] Infrared sensors detect infrared rays emitted by hot objects and are used in automatic doors, surveillance cameras, infrastructure inspections, etc. Infrared rays have a wide wavelength range, so there is a demand for broadband, highly sensitive sensors that can operate at room temperature.

[0003] Electromagnetic wave detectors using graphene layers have been proposed (see, for example, Patent Document 1). Graphene has high mobility and absorbs light in a wide wavelength range, including visible and infrared. Due to these properties of graphene, research and development is being conducted toward practical use of sensors that are smaller than conventional ones and operate at room temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 121408 Summary of the Invention [Problem to be solved by the invention]

[0005] A typical graphene sensor has a transistor structure with electrodes on both ends of the graphene layer, and detects carriers generated when light is incident on the graphene as a current. In a graphene sensor with a transistor structure, if the graphene is exposed to the air, the drain current-gate voltage curve changes due to the influence of moisture in the air, contamination, climate change, etc. If the drain current-gate voltage curve changes, the change characteristics of the drain current depending on whether or not light is incident fluctuates, and the amount of received light cannot be detected correctly. If a protective film is provided to cover the graphene surface, sufficient sensitivity cannot be obtained depending on the type of protective film.

[0006] In one aspect, an object of the present invention is to provide an optical sensor device that is both weather resistant and sensitive. [Means for solving the problem]

[0007] In one embodiment, the optical sensor device comprises: A substrate; a graphene layer provided on the substrate; A pair of electrodes connected to the graphene layer; a resin layer covering a light receiving region of the graphene layer and transparent to a wavelength band of light to be detected; has. Effect of the Invention

[0008] This realizes an optical sensor device that is both weather resistant and sensitive. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates the environmental effects on a graphene-based optical sensor device. [Diagram 2] FIG. 1 is a diagram showing the weather resistance of a protective film formed by an atomic layer deposition (ALD) method. [Diagram 3] 1 is a diagram illustrating the principle of an optical sensor device using graphene. [Figure 4] FIG. 2 is a schematic plan view of the optical sensor device according to the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view taken along line IV-IV in FIG. [Figure 6A] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 6B] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 6C] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 6D] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 6E] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 6F] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 6G] 3A to 3C are manufacturing process diagrams of the optical sensor device according to the first embodiment. [Figure 7] FIG. 1 is a diagram showing the effect of a resin layer according to an embodiment in comparison with an ALD alumina film. [Figure 8] FIG. 11 is a schematic plan view of an optical sensor device according to a second embodiment. [Figure 9] 9 is a cross-sectional view taken along line VV in FIG. 8. [Figure 10A] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10B] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10C] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10D] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10E] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10F] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10G] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10H] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10I] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10J] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 10K] 10A to 10C are manufacturing process diagrams of the optical sensor device according to the second embodiment. [Figure 11] FIG. 13 is a schematic plan view of an optical sensor device according to another embodiment. [Figure 12] 12 is a cross-sectional view taken along line VI-VI in FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In the embodiment, the light receiving region of the optical sensor device using graphene is covered with a resin layer that is transparent to the light to be detected, thereby improving weather resistance and sensitivity. Weather resistance generally refers to the property of being able to withstand the outdoor natural environment and its changes, but in the optical sensor device 10 of the embodiment, the weather resistance includes the property of suppressing the fluctuation of the Dirac point even if the environment in which the optical sensor device is used changes.

[0011] Preferably, the resin layer has photosensitivity to light having a wavelength different from that of the light to be detected, or to electron beams. Such a resin layer is formed by a coating method such as spin coating, spray coating, dip coating, die coating, or bar coating, and is easy to form and pattern. The baking temperature is also 100° C. or less, and has little effect on graphene.

[0012] By covering the light receiving region of the graphene with a resin layer, the effect of p-doping to the graphene is greater than that of an inorganic insulating film formed by the ALD method, as described below, and the sensitivity of the optical sensor device is improved. The "effect of p-doping" here refers to the effect of increasing the carrier (hole) concentration in the graphene. The effect of p-doping increases the difference in drain current between when light is incident and when it is not, improving the light receiving sensitivity.

[0013] Figure 1 shows the effect of the environment on a graphene-based optical sensor device. As a sample, a graphene optical device with a transistor structure is fabricated, in which a pair of electrodes is provided on a graphene layer on a substrate and a gate electrode is provided on the back side of the substrate. Using the fabricated sample, the gate voltage-drain current characteristics are measured in vacuum when no light is incident. The sample is vacuum annealed at 150°C for 1 hour to simulate a state in which the moisture content of the device surface is low. A sample that is not vacuum annealed is used to simulate a state in which the moisture content of the device surface is high.

[0014] The gate voltage-drain current characteristics are significantly different when the moisture content of the device surface is low (line A) and when the moisture content is high (line B). When the moisture content of the device surface is low, the Dirac point, i.e., the point at which the drain current is at a minimum relative to the gate voltage, is near 0 V. In contrast, when the moisture content of the device surface is high, the Dirac point shifts significantly to the positive side of the gate voltage, and the drain current-gate voltage characteristics themselves change, narrowing the dynamic range.

[0015] In order to improve the weather resistance of a graphene-based optical sensor device, it is possible to cover the entire device with a protective film. For example, a transparent insulating protective film can be formed by the ALD method, which can form a dense film, to prevent the effects of moisture and contamination.

[0016] Figure 2 shows the weather resistance of a protective film formed by the ALD method. A 20 nm thick Al2O3 film was formed as a protective film on the same sample as in Figure 1. Line C shows the electrical properties of the sample that was annealed after the protective film was formed by ALD. Line D shows the electrical properties measured in vacuum after the protective film was formed by ALD without annealing. Line E shows the electrical properties measured in air after the protective film was formed by ALD without annealing.

[0017] Regardless of whether annealing is performed or not, the Dirac point remains almost constant and is located near the gate voltage of 0 V. It can be seen that by forming a protective layer using the ALD method, fluctuations in the Dirac point are suppressed regardless of changes in the moisture content of the environment, improving weather resistance.

[0018] The inventors found that the protective film formed by the ALD method has weather resistance, but the effect of p-doping is insufficient. If weather resistance and the effect of p-doping can be achieved at the same time, a highly sensitive optical sensor device with stable operation can be realized. In the embodiment, a resin layer that is transparent to the light to be detected is used as the protective layer.

[0019] Figure 3 shows the principle of the optical sensor device. The horizontal axis is the gate voltage, and the vertical axis is the drain current. When there is no incident light, the Dirac point where the drain current is at a minimum is at DP1. When light is incident on the graphene, carriers are generated in the graphene, and the Dirac point shifts to DP2 on the lower voltage side. In other words, the drain current increases with the same gate voltage. The amount of incident light can be determined by measuring the change in the drain current. Instead of measuring the drain current, the change in electrical resistance may be measured.

[0020] In the vicinity of the Dirac point, the change in current (slope) when light is incident is large. By applying a bias voltage between the source and drain, the change in current or electrical resistance at the Dirac point can be read. If the effect of p-doping is large, the change in drain current or electrical resistance becomes large with the same amount of incident light, and the sensitivity becomes high. The inventors found that the effect of p-doping can be fully obtained by using a resin layer as a protective layer. The effect of p-doping by the resin layer will be described later with reference to FIG. 7.

[0021] First Embodiment Fig. 4 is a schematic plan view of the optical sensor device 10A of the first embodiment, and Fig. 5 is a cross-sectional view taken along line IV-IV in Fig. 4. The optical sensor device 10A includes a substrate 11, a graphene layer 15 provided on the substrate 11 via an insulating film 13, electrodes 18 and 19 connected to the graphene layer 15, and a resin layer 25 covering at least a light receiving region 155 of the graphene layer 15. The light receiving region 155 of the graphene layer 15 is a region extending between the electrodes 18 and 19. The resin layer 25 is transparent to light detected by the optical sensor device 10A, and is transparent to visible light and infrared light in this example.

[0022] The resin layer 25 is a resin coat formed by a method such as spin coating, spray coating, dip coating, die coating, or bar coating, and has good adhesion to the base. The thickness of the resin layer 25 is 1 μm to several μm. When the resin layer 25 is used as a protective layer, a large-scale film forming device equipped with a vacuum chamber is not required.

[0023] In the substrate 11, the surface on which the graphene layer 15 and the electrodes 18, 19 are formed is referred to as the main surface, and the side opposite to the main surface is referred to as the back surface. For convenience, the stacking direction of the main surface is referred to as the "upper" side, but such an expression of a direction does not indicate an absolute positional relationship. The substrate 11 is, for example, a silicon substrate, and a gate electrode 14 is provided on the back surface of the substrate 11. The gate electrode 14 and the electrodes 18 and 19 form a transistor structure.

[0024] The electrode pads 16 and 17 are provided for wire bonding with a bonder. The electrode pads 16 and 17 are formed, for example, of a laminate of titanium (Ti) and gold (Au). Chromium (Cr) may be used as the base for Au instead of Ti.

[0025] The electrodes 18, 19 are formed of Au, Ti, Cr, palladium (Pd), platinum (Pt), a combination of these, etc. If the electrodes 18, 19 have sufficient adhesion to the insulating film 13, the electrode pads 16, 17 may be omitted.

[0026] Contact holes 22, 23 reaching the electrodes 18, 19 are formed in the resin layer 25. By filling the contact holes 22, 23 with a conductive material to provide wiring or terminals, the current flowing through the channel of the graphene layer 15 can be extracted to the outside.

[0027] The resin layer 25 may be a photosensitive resin having photosensitivity to, for example, ultraviolet light. In this case, the contact holes 22, 23 can be easily formed by only exposing and developing the resin layer 35. When the resin layer 25 is formed of a photoresist, the photoresist may be either negative or positive from the viewpoint of patterning, but in terms of weather resistance, the negative type may be superior to the positive type.

[0028] By protecting the optical sensor device 10A with the resin layer 25, the intrusion of moisture and contamination is prevented, and weather resistance is improved. In addition, as will be described later, the p-doping effect on the graphene layer 15 is improved, and the light receiving sensitivity can be increased.

[0029] 6A to 6G are diagrams showing the manufacturing process of the optical sensor device 10A of the first embodiment. In FIG. 6A, for example, a silicon substrate with a thermal oxide film is prepared. The silicon substrate is used as the substrate 11, and the thermal oxide film on one surface (main surface) is used as the insulating film 13. The thermal oxide film on the surface (back surface) of the substrate 11 opposite the insulating film 13 is removed to form a gate electrode 14. A two-layer electrode of Ti and Au may be formed on the back surface of the substrate 11 by electron beam (EB) deposition to serve as the gate electrode. The gate electrode 14 serves as a back gate.

[0030] 6B, electrode pads 16 and 17 are formed on the insulating film 13. The electrode pads 16 and 17 are formed as a two-layer metal film of Ti and Au, for example, by a lift-off method. In order to keep the electrical conductivity as high as possible, the thickness of the underlying Ti film, which serves as an adhesive layer, may be formed as thin as possible.

[0031] In FIG. 6C, a graphene layer 15 is provided on the entire surface. The graphene layer 15 may be applied onto the insulating film 13 and the electrode pads 16 and 17 by a mechanical peeling method in which HOPG (Highly oriented pyrolytic graphite) is peeled off with a tape or the like, or a transfer method in which graphene synthesized on a catalyst such as copper foil by chemical vapor deposition is peeled off and transferred using a resin or the like. The graphene layer 15 may be a single layer of graphene, or may be a layer having a thickness of several atomic layers. Since the amount of light absorption per layer of graphene is small, the amount of light absorption may be increased by stacking multiple layers of graphene. After providing the graphene layer 15, annealing may be performed at a temperature of 150 to 200° C. to increase the adhesion between the insulating film 13 and the graphene.

[0032] 6D, the graphene layer 15 is patterned into a predetermined shape. Graphene can be processed by oxygen ashing, oxygen ion beam, or the like.

[0033] 6E, electrodes 18 and 19 are formed to overlap both ends of the processed graphene layer 15. The electrodes 18 and 19 cover the electrode pads 16 and 17, respectively, on the substrate 11, but may be integrally formed of the same material. The region of the graphene layer 15 that extends between the electrodes 18 and 19 is the light-receiving region 155. The graphene layer 15 forms a channel between the electrodes 18 and 19.

[0034] In FIG. 6F, a resin layer 25 is formed on the entire surface. For the resin layer 25, a resin that is transparent in the wavelength region of the light to be detected and has a p-doping effect on the graphene layer 15, such as an epoxy-based resin, is used. In this example, SU-8 resist manufactured by MicroChem is used. The SU-8 resist is applied to the entire surface with a thickness of 1 μm to several μm (1 μm in this example) using a spinner, and baked at 95° C. using a hot plate.

[0035] In Fig. 6G, contact holes 22, 23 reaching the electrodes 18, 19 are formed at predetermined positions of the resin layer 25 by exposure and development. Exposure may be by irradiation with ultraviolet light using a mask aligner exposure device. Depending on the type of resin used, exposure may also be by electron beams. Wiring or terminals may be formed in the contact holes 22, 23.

[0036] Although the manufacturing process has been described above with a focus on individual optical sensor devices 10A, a large number of optical sensor devices 10A may be simultaneously formed in each chip region on a silicon wafer to form an optical sensor device array.

[0037] By applying a predetermined bias voltage between electrodes 18 and 19, an electric field is applied to the graphene layer 15, and electron-hole pairs generated by light (e.g., infrared light) incident on the light receiving region 155 of the graphene layer 15 flow through the graphene layer 15. The drain current can be controlled by the gate voltage. By applying a gate voltage at the Dirac point where the drain current is minimized with the light incidence OFF, the drain current increases due to the light incidence. The light incidence can be detected by detecting this increase in the drain current.

[0038] Fig. 7 shows the p-doping effect of the resin layer 25. In order to confirm the p-doping effect of the resin layer 25, the drain current-gate voltage characteristics are measured without light incidence for the sample fabricated by the steps of Figs. 6A to 6G. For comparison, a sample is fabricated in which an alumina film formed by the ALD method is used as a protective layer, and the drain current-gate voltage characteristics are similarly measured without light incidence.

[0039] Figure 7(a) shows the measurement results in air of seven types of samples a to g that have a protective layer of resin layer 25. Figure 7(b) shows the measurement results in air of five types of samples h to l that have a protective layer of a 20 nm-thick ALD alumina film.

[0040] In samples a to g having resin layer 25, single-layer graphene is used, the length of graphene layer 15 (length between electrodes 18 and 19) is constant at 30 mm, and the width is varied between 1 mm and 50 mm. Resin layer 25 is SU-8 resist. In samples h to l of the comparative example, single-layer graphene is used, the length of graphene layer is constant at 30 mm, and the width is varied between 5 mm and 300 mm.

[0041] In the samples of the embodiment, except for sample a with a width of 1 mm, the Dirac point is stable near 15 V regardless of changes in the width of the graphene layer 15. It can be seen that the effect of p-doping is apparent.

[0042] In contrast, in the comparative samples h to l, the Dirac point shifts due to the change in the width of the graphene layer 15, so the gate voltage setting must be changed according to the device design. In addition, the Dirac point is 5 V or less except for sample h, and the effect of p-doping is small.

[0043] From this measurement result, it is understood that by providing the resin layer 25 that is transparent to the light to be detected, the optical sensor device 10A having both weather resistance and sensitivity can be realized.

[0044] <Second embodiment> Fig. 8 is a schematic plan view of an optical sensor device 10B according to the second embodiment, and Fig. 9 is a cross-sectional view taken along line VV in Fig. 8. In the second embodiment, in order to enhance light absorption by the graphene layer 15, a plurality of holes 151 are provided in a light receiving region 155 of the graphene layer 15.

[0045] The optical sensor device 10B has a substrate 11, a graphene layer 15 provided on the substrate 11 via an insulating film 13, electrodes 18 and 19 connected to the graphene layer 15, and a resin layer 25 covering at least a light receiving region 155 of the graphene layer 15. The resin layer 25 is transparent to light detected by the optical sensor device 10B, and is transparent to visible light and infrared light in this example.

[0046] A plurality of holes 151 are formed in the light receiving region 155 of the graphene layer 15. By providing the holes 151 in the graphene layer 15, it is possible to enhance the absorption of light when the light is received. When light is incident, plasmons, i.e., collective oscillations of free electrons caused by the incident light, are excited on the surface of the graphene layer 15. In the vicinity of the edges of the holes 151, the confinement of the oscillating electric field of light is strong, and it is possible to enhance the absorption of light compared to a graphene layer in which the holes 151 are not formed. The holes 151 do not necessarily need to completely penetrate the graphene layer 15 to reach the insulating film 13.

[0047] Electrodes 18 and 19 are disposed on both ends of the graphene layer 15 so as to overlap the graphene layer 15. A gate electrode 19 is provided on the back surface of the substrate 11, forming a back-gate type transistor configuration.

[0048] Except for the holes 151 provided in the graphene layer 16, the optical sensor device 10B has the same configuration as the optical sensor device 10A of the first embodiment. The same components as those in the optical sensor device 10A are denoted by the same reference numerals, and duplicated explanations will be omitted. The weather resistance provided by the resin layer 25 and the effect of p-doping are also the same as in the first embodiment, but the amount of light absorption in the graphene layer 15 increases, thereby further improving sensitivity.

[0049] 10A to 10K are diagrams showing the manufacturing process of the optical sensor device 10B. The processes shown in FIG. 10A to FIG. 10D are the same as those shown in FIG. 6A to FIG. 6D. That is, the thermal oxide film on one side of a silicon substrate with a thermal oxide film is used as an insulating film 13, and the thermal oxide film on the other side is removed to form a gate electrode 14. After forming electrode pads 16 and 17 on the insulating film 13, a graphene layer 16 is provided on the entire surface, and the graphene layer 15 is patterned into a predetermined shape.

[0050] In FIG. 10E, a resist 31 for forming holes is applied to the entire surface. The resist 31 is a resin that is easy to pattern and to remove with a solvent. Examples of such resins include acrylic resin, polymethyl methacrylate (PMMA), hydrogen silsesquioxane (HSQ), etc. Alternatively, multiple types of these may be layered.

[0051] 10F, an opening 32 of a predetermined shape is formed in the resist 31 by electron beam lithography, and a part of the graphene layer 15 is exposed in the opening 32. The diameter of the opening 32 is about 100 to 400 nm.

[0052] 10G, resist 31 with openings 32 formed therein is used as a mask, and periodic holes 151 are formed in graphene layer 15 with a directional oxygen ion beam. The diameter of holes 151 formed in graphene layer 15 may be in the range of 100 to 400 nm, for example, and the diameter and arrangement of holes 151 can be adjusted depending on the wavelength of light to be absorbed. The planar shape of the holes is not limited to a circular shape, and any planar shape may be used as long as it is a shape that can excite plasmons.

[0053] 10H, the resist 31 is removed. This resist 31 is for patterning the holes 151, and is easily removed with a solvent or the like.

[0054] The steps of Fig. 10I to Fig. 10K are the same as the steps of Fig. 6E to Fig. G. That is, electrodes 18 and 19 are formed to cover the electrode pads 16 and 17 and connect to both ends of the graphene layer 15 in which the hole 151 is formed, and a resin layer 25 is formed on the entire surface. For the resin layer 25, a resin that is transparent in the wavelength region of the light to be detected, has a low dielectric constant, and has good adhesion to the base is used. For example, SU-8 resist manufactured by MicroChem is spin-coated to a thickness of 1 to several µm. After baking at a low temperature of 100°C or less, contact holes 22 and 23 reaching the electrodes 18 and 19 are formed by exposure and development. Wiring or terminals may be formed in the contact holes 22 and 23.

[0055] In the optical sensor device 10B, weather resistance is improved by the resin layer 25, and sensitivity is improved by the effect of p-doping. In the optical sensor device 10B, periodic holes 151 are provided in the graphene layer 25 to enhance light absorption and further improve sensitivity.

[0056] <Other embodiments> Fig. 11 is a schematic plan view of an optical sensor device 10C according to another embodiment, and Fig. 12 is a cross-sectional view taken along line VI-VI in Fig. 11. The optical sensor device 10C has a buried gate electrode 24 instead of a back gate.

[0057] A gate electrode 24 is provided on an insulating film 13 on a substrate 11. The substrate 11 is not limited to a silicon substrate, and any insulating substrate such as a sapphire substrate, an MgO substrate, or a resin substrate may be used. When a silicon substrate is used, the insulating film 13 may be a thermally oxidized film, or may be an insulating film newly formed after removing the thermally oxidized film. When an insulating substrate is used, the insulating film 13 may be formed on the surface of the substrate 11 by sputtering or the like. The gate electrode 24 is formed on the insulating film 13 by EB deposition or the like.

[0058] Another insulating film 27 is provided to cover the gate electrode 24. The graphene layer 15 is disposed on the insulating film 27. The insulating film 27 directly below the graphene layer 15 serves as a gate insulating film. By applying a gate voltage to the graphene layer 15 via the insulating film 27, the density of carriers such as electrons and holes in the graphene layer 15 is controlled.

[0059] In the optical sensor device 10C, it is possible to fabricate an integrated circuit because all the electrodes are provided on the main surface side of the substrate 11. In the optical sensor device 10C, a resin layer 25 is provided to cover the graphene layer 15, improving weather resistance and improving sensitivity due to the effect of p-doping.

[0060] As another configuration, instead of forming the electrode pads 16, 17 on the insulating film 13, the contact holes 18, 19 may be formed in the resin layer 25, and then the electrode pads may be formed in the contact holes by a lift-off method.

[0061] Although the present disclosure has been described above based on specific examples, the present disclosure is not limited to the above examples. Each embodiment may be combined with each other. For example, the holed graphene layer 15 of the second embodiment may be combined with the configuration of the buried gate electrode of FIGS. 11 and 12. The shape (including width and length) and the number of layers of the graphene layer 15 may be appropriately designed. When forming holes 151 in the graphene layer 15, the holes 151 are not limited to circular holes, and may be polygonal, elliptical, or other holes. The arrangement of the holes 151 is not limited to the matrix arrangement of FIG. 8, and may be an alternating arrangement or a closely packed arrangement.

[0062] Resin layer 25 may be made of epoxy resin as a main component, with a few to 10% by weight of ultraviolet (UV) curable resin and about 1 to 5% of an adhesion promoter added. By protecting at least light receiving region 155 of graphene layer 15 with resin layer 25, it is expected that weather resistance will be improved and sensitivity will be improved due to the effect of p-doping. [Explanation of symbols]

[0063] 10A, 10B, 10C Optical sensor devices 11 Substrate 13. Insulating film 14, 24 Gate electrode 16, 17 Electrode pads 18, 19 electrode 15 graphene layers 25 Resin layer 151 holes

Claims

1. A substrate; a graphene layer provided on the substrate; A pair of electrodes connected to the graphene layer; a resin layer covering a light receiving region of the graphene layer and transparent to light to be detected; having The resin layer is mainly composed of an epoxy resin and has a p-doping effect on the graphene layer.

2. The resin layer has photosensitivity to light having a wavelength different from that of the light to be detected or to an electron beam. The optical sensor device of claim 1 .

3. The resin layer has photosensitivity to ultraviolet light. The optical sensor device according to claim 2 .

4. The resin layer is a negative or positive photoresist.

4. An optical sensor device according to claim 1.

5. A substrate, a graphene layer provided on the substrate; A pair of electrodes connected to the graphene layer; a resin layer covering a light receiving region of the graphene layer and transparent to light to be detected; having The optical sensor device, wherein the resin layer is SU-8 photoresist.

6. The resin layer is a layer formed by a coating method.

6. An optical sensor device according to any one of the preceding claims.

7. the graphene layer has a periodic arrangement of a plurality of holes formed in the light receiving region; The resin layer covers the light receiving area in which the hole is formed.

7. An optical sensor device according to any one of claims 1 to 6.

8. a gate electrode provided on the back surface of the substrate or between the substrate and the graphene layer; 8. The optical sensor device according to claim 1, further comprising:

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