Graphene optical sensor manufacturing method

Abstract

To effectively manufacture a graphene light sensor.SOLUTION: A manufacturing method of a graphene light sensor comprise the steps of: growing a graphene 30 on a metal layer 20 provided in a substrate 10 for growing; forming a pattern of an opening portion 41 by performing an imprint on a resist layer 40 formed in such a way to cover the graphene 30; etching the graphene 30 by using the resist layer 40 as a mask; then removing the metal layer 20 and separating the graphene 30 and the resist layer 40 holding the graphene 30 from the substrate 10 for growing; and transferring the separated graphene 30 and the resist layer 40 to a the substrate 50 for the device and removing the resist layer 40. Thus, the formation of a resist mask for a graphene etching by an EB lithography after the transference to substrate 50 for the device becomes unnecessary. The EB lithography requiring a relatively long time is unnecessary, and consequently, producibility of a graphene light sensor including the graphene 30 is increased.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a graphene optical sensor. [Background technology]

[0002] A known technique involves providing a graphene layer, which is an organic semiconductor layer, on a flexible substrate of a device, covering the graphene layer with an imprint layer, patterning the imprint layer by imprinting, and then forming non-conductive slits that penetrate the graphene layer by etching.

[0003] Another known technique involves forming an insulating film on a substrate on which a gate electrode is provided, forming a resist layer using PMMA on the insulating film, forming a mask by forming irregularities in the resist layer by nanoimprinting, and then forming recesses in the insulating film by etching. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2012 / 0305892 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-63059 Summary of the Invention [Problem to be solved by the invention]

[0005] A graphene optical sensor is known, which has a structure in which a source electrode and a drain electrode are connected to graphene that faces a gate portion via an insulating film. In manufacturing such a graphene optical sensor, graphene is grown on a catalytic metal layer provided on a growth substrate, and the grown graphene is transferred to a device substrate including a gate portion and an insulating film. The graphene transferred to the device substrate is then patterned using lithography technology, and a source electrode and a drain electrode are formed so as to be connected to the patterned graphene.

[0006] Here, electron beam (EB) lithography, which is less affected by steps on the device substrate, is sometimes used for graphene patterning. However, in this case, EB lithography takes a relatively long time, which can make it difficult to efficiently manufacture graphene optical sensors.

[0007] In one aspect, the present invention aims to efficiently fabricate graphene optical sensors. [Means for solving the problem]

[0008] In one embodiment, a method for manufacturing a semiconductor device includes growing graphene on a side of a metal layer provided on a first surface of a first substrate opposite the first substrate, forming a resist layer on the side of the graphene opposite the metal layer, forming a pattern on the resist layer by imprinting, and etching the graphene using the resist layer on which the pattern has been formed as a mask. after the step of etching the graphene, removing the metal layer and separating the graphene held by the resist layer from the first substrate; A method for manufacturing a graphene optical sensor is provided, comprising: [Effects of the Invention]

[0009] In one aspect, it enables efficient fabrication of graphene optical sensors. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram (part 1) illustrating an example of a method for manufacturing a graphene optical sensor. [Figure 2] FIG. 10 is a diagram (part 2) illustrating an example of a method for manufacturing a graphene optical sensor. [Figure 3] FIG. 10 is a diagram (part 3) illustrating an example of a method for manufacturing a graphene optical sensor. [Figure 4] FIG. 10 is a diagram (part 4) for explaining an example of a method for manufacturing a graphene optical sensor. [Figure 5]FIG. 1 is a diagram (part 1) illustrating an example of a method for manufacturing a graphene optical sensor using a device substrate having a step. [Figure 6] FIG. 10 is a diagram (part 2) illustrating an example of a method for manufacturing a graphene optical sensor using a device substrate having a step. [Figure 7] 1A to 1C are diagrams illustrating an example of a method for forming graphene having antidots on a device substrate having steps. [Figure 8] 1A to 1C are diagrams (part 1) illustrating an example of a method for manufacturing a graphene optical sensor according to a first embodiment. [Figure 9] FIG. 10 is a diagram (part 2) illustrating an example of a method for manufacturing the graphene optical sensor according to the first embodiment. [Figure 10] FIG. 10 is a diagram (part 3) illustrating an example of a method for manufacturing the graphene optical sensor according to the first embodiment. [Figure 11] FIG. 10 is a diagram (part 4) illustrating an example of a method for manufacturing the graphene optical sensor according to the first embodiment. [Figure 12] FIG. 5 is a diagram (part 5) illustrating an example of a method for manufacturing the graphene optical sensor according to the first embodiment. [Figure 13] 10A to 10C are diagrams illustrating an example of a method for manufacturing a graphene optical sensor according to a second embodiment. [Figure 14] 3A to 3C are diagrams illustrating a part of the manufacturing process of the graphene optical sensor according to the first and second embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0011] First, an example of a method for manufacturing a graphene optical sensor will be described. Figures 1 to 4 are diagrams illustrating an example of a method for manufacturing a graphene optical sensor. Figures 1(A) to 1(D), 2(A) to 2(C), 3(A) to 3(D), and 4(A) to 4(D) each show a schematic cross-sectional view of a main part of an example of a manufacturing process for a graphene optical sensor.

[0012] First, a growth substrate 10 for growing graphene is prepared, as shown in FIG. 1(A). A metal layer 20, which serves as a catalyst when growing graphene, is provided on one surface 10a of the growth substrate 10. The growth substrate 10 may be, for example, a sapphire substrate (α-Al2O3). The metal layer 20 may be, for example, copper (Cu). In this case, the copper of the metal layer 20 is provided on the surface 10a of the growth substrate 10 so that the surface 20a opposite to the growth substrate 10 is a (111) plane.

[0013] After preparing a growth substrate 10 provided with a catalytic metal layer 20, graphene 30 is grown on a surface 20a of the metal layer 20 provided on the growth substrate 10, as shown in FIG. 1(B). The graphene 30 is grown, for example, by a chemical vapor deposition (CVD) method. For example, hydrocarbons such as methane (CH4) and ethylene (CH2CH2) are used as carbon sources for growing graphene 30 using the CVD method. Graphene 30 may also be grown (or synthesized) using a fused polycyclic aromatic hydrocarbon in which multiple benzene rings are fused as a precursor.

[0014] After the growth of the graphene 30, as shown in FIG. 1(C), a resist layer 40 is formed on the side of the graphene 30 opposite to the metal layer 20 and the growth substrate 10. The resist layer 40 serves to hold the graphene 30 in place when it is separated from the growth substrate 10 as described below. The resist layer 40 may be made of, for example, polymethylmethacrylate (PMMA).

[0015] After the resist layer 40 is formed, the metal layer 20 used for growing the graphene 30 is removed, as shown in FIG. 1(D). For example, if copper is used for the metal layer 20, the copper metal layer 20 is selectively removed by wet etching using an aqueous solution of iron nitrate (Fe(NO3)3). By removing the metal layer 20, the graphene 30 is separated from the growth substrate 10 while being held by the resist layer 40.

[0016] The graphene 30 separated from the growth substrate 10 by removing the metal layer 20 and the resist layer 40 holding it are transferred to a device substrate 50 for forming a graphene optical sensor, for example, as shown in Figures 2(A) to 2(C).

[0017] Here, the device substrate 50 includes a semiconductor substrate 51, an insulating film 52, a gate electrode 53, and an insulating film . A low-resistivity silicon (Si) substrate heavily doped with impurities of a predetermined conductivity type is used as the semiconductor substrate 51. The semiconductor substrate 51 functions as a back gate of the graphene optical sensor. The semiconductor substrate 51 is an example of a gate portion of the graphene optical sensor.

[0018] The insulating film 52 is made of an insulating material such as silicon oxide (SiO2). The insulating film 52 is formed on the surface of a semiconductor substrate 51 that functions as a back gate of the graphene optical sensor. The insulating film 52 is stacked on the semiconductor substrate 51. The insulating film 52 functions as a back gate insulating film of the graphene optical sensor. The insulating film 52 is an example of a gate insulating film of the graphene optical sensor.

[0019] The gate electrode 53 is made of a metal material such as gold (Au). The gate electrode 53 is an example of a conductive layer formed on a part of the insulating film 52 that functions as a back gate insulating film of the graphene optical sensor. The gate electrode 53 is stacked on a part of the insulating film 52. The gate electrode 53 functions as a half gate of the graphene optical sensor. The gate electrode 53 is an example of a gate portion of the graphene optical sensor.

[0020] The insulating film 54 is made of an insulating material such as aluminum oxide (Al2O3). The insulating film 54 is formed so as to cover the insulating film 52, which functions as a back-gate insulating film of the graphene optical sensor, and the gate electrode 53, which is laminated on a part of the insulating film 52 and functions as a half-gate of the graphene optical sensor. The insulating film 54 is laminated on the insulating film 52 and the gate electrode 53. The insulating film 54 functions as a half-gate insulating film of the graphene optical sensor. The insulating film 54 is an example of a gate insulating film of the graphene optical sensor.

[0021] An insulating film 54 that covers a conductive layer such as the gate electrode 53 is provided on one surface 50 a of the device substrate 50 . The device substrate 50 may have a step on the surface 50a on which the gate electrode 53, the insulating film 54, etc. are formed, due to the arrangement of the conductive layers such as the gate electrode 53. The configuration of the device substrate 50 having such a step will be described in detail later.

[0022] The graphene 30 separated from the growth substrate 10 as described above and the resist layer 40 holding it are transferred to the prepared device substrate 50. 2(A), for example, the graphene 30 held by the resist layer 40 is floated on a liquid 100 (a liquid surface 100a) such as water. At this time, the graphene 30 held by the resist layer 40 is floated on the liquid surface 100a so that the graphene 30 faces the liquid surface 100a. Then, the graphene 30 floating on the liquid surface 100a and the resist layer 40 holding it are scooped up on the surface 50a side of the device substrate 50 on which the gate electrode 53, the insulating film 54, and the like are formed.

[0023] By scooping up the structure 2 in this manner, a structure 2 as shown in FIG. 2(B) is obtained, i.e., a structure 2 in which graphene 30 supported by the resist layer 40 is laminated on the surface 50a side of the device substrate 50. The obtained structure 2 is subjected to a heat treatment. This heat treatment is performed for the purpose of evaporating and removing the liquid 100 remaining on the surface of the structure 2 and between the device substrate 50 and the graphene 30, and fixing the graphene 30 to the device substrate 50. For example, the heat treatment is performed under conditions of 180°C and 3 minutes.

[0024] After the heat treatment, the resist layer 40 is removed as shown in Fig. 2(C). For example, the PMMA resist layer 40 is selectively removed by wet etching using an organic solvent. This results in a structure 3 as shown in Fig. 2(C), i.e., a structure 3 in which graphene 30 is laminated on the surface 50a side (insulating film 54 provided on the surface 50a) of the device substrate 50 on which the gate electrode 53, insulating film 54, etc. are formed.

[0025] After the structure 3 is formed, as shown in FIG. 3A, a resist layer 60 is formed on the side of the graphene 30 opposite to the device substrate 50. The resist layer 60 is made of, for example, PMMA. The resist layer 60 is patterned by, for example, photolithography. The resist layer 60 is formed so as to cover the arrangement region of the graphene 30 in the graphene optical sensor.

[0026] After the resist layer 60 is formed, as shown in Fig. 3(B), a portion of the graphene 30 is selectively removed by etching using the resist layer 60 as a mask. For example, a portion of the graphene 30 is removed by dry etching such as reactive ion etching (RIE) using a gas containing oxygen (O).

[0027] After etching the graphene 30, the resist layer 60 is removed. This results in a structure 4 as shown in Fig. 3(C), i.e., a structure 4 in which the graphene 30 is patterned in an arrangement region of the graphene optical sensor. The graphene 30 is arranged in a region where a part of it faces the gate electrode 53 with the insulating film 54 interposed therebetween.

[0028] In order to increase the sensitivity of the graphene optical sensor, antidots may be formed by surface plasmon excitation to increase the light absorption efficiency of the graphene 30. The antidots are patterns in which some carbon atoms in the graphene 30 are missing.

[0029] When forming such antidots on the graphene 30, after the formation of the structures 4, a resist layer 70 is first formed to cover the graphene 30, as shown in Fig. 3(D) . The resist layer 70 is made of, for example, PMMA.

[0030] After the resist layer 70 is formed, as shown in FIG. 4A, openings 71 of a pattern for forming a plurality of antidots in the graphene 30 are formed in the resist layer 70. EB lithography is used to form the openings 71 in the resist layer 70. EB exposure (or drawing) and development are performed on the resist layer 70, and the openings 71 for forming antidots in the graphene 30 are formed in the resist layer 70.

[0031] After the openings 71 are formed in the resist layer 70, the graphene 30 in the openings 71 is selectively removed by etching using the resist layer 70 as a mask, as shown in FIG. 4B. For example, the graphene 30 in the openings 71 in the resist layer 70 is removed by dry etching such as RIE using a gas containing oxygen. As a result, antidots 31 are formed in the graphene 30.

[0032] After the antidots 31 of the graphene 30 are formed, the resist layer 70 is removed, thereby obtaining the structure 5 as shown in Fig. 4(C), that is, the structure 5 including the graphene 30 on which the antidots 31 are formed.

[0033] After the structure 5 is formed, as shown in FIG. 4(D), a source electrode 80 and a drain electrode 90, which are electrode layers, are formed on the ends of the graphene 30 on which the antidots 31 are formed. The source electrode 80 and the drain electrode 90 are made of a metal material such as gold. The source electrode 80 and the drain electrode 90 are each connected to the ends of the graphene 30. The source electrode 80 and the drain electrode 90 are connected to the ends of the graphene 30 so that the gate electrode 53 is located between them.

[0034] As described above, by the steps shown in Figures 1(A) to 1(D), 2(A) to 2(C), 3(A) to 3(D), and 4(A) to 4(D), a graphene optical sensor 1 having a configuration as shown in Figure 4(D) is manufactured.

[0035] In addition, when the antidots 31 are not provided on the graphene 30, after the step of FIG. 3(C), a source electrode 80 and a drain electrode 90 are formed on the ends of the graphene 30 according to the example of the step of FIG. 4(D).

[0036] Next, the configuration of the device substrate 50 used in the graphene photosensor 1 as described above, and the formation of the graphene 30, the source electrode 80, and the drain electrode 90 on the device substrate 50 will be further described.

[0037] In the device substrate 50 on which the graphene 30, the source electrode 80, and the drain electrode 90 are formed as described above, there may be a step on the surface 50a on which they are formed due to the arrangement of conductive layers such as the gate electrode 53.

[0038] 5 and 6 are diagrams illustrating an example of a method for manufacturing a graphene optical sensor using a device substrate having a step. FIGS. 5(A) to 5(D) each show a schematic cross-sectional view of a key part of an example of a manufacturing process for a graphene optical sensor using a device substrate having a step. FIG. 6(A) shows a schematic cross-sectional view of a key part of an example of a graphene optical sensor manufactured using a device substrate having a step, and FIG. 6(B) shows a schematic plan view of a key part of an example of a graphene optical sensor manufactured using a device substrate having a step. FIG. 6(A) is a cross-sectional view corresponding to the position of line VI-VI in FIG. 6(B). For convenience, the insulating film 52 and insulating film 54 shown in FIG. 6(A) are omitted in FIG. 6(B).

[0039] As shown in FIG. 5A, the device substrate 50 includes a semiconductor substrate 51 that functions as a back gate, an insulating film 52 that functions as a back gate insulating film, a gate electrode 53 that functions as a half gate, and an insulating film 54 that functions as a half gate insulating film. The gate electrode 53 is interposed between the insulating film 52 and the insulating film 54. As shown in FIG. 5A, the device substrate 50 further includes wiring 55 and wiring 56 that are interposed between the insulating film 52 and the insulating film 54, similar to the gate electrode 53. The wiring 55 and wiring 56 are made of a metal material such as gold. The wiring 55 and wiring 56 are examples of conductive layers. Parts of the wiring 55 and wiring 56 are exposed from the insulating film 54. A source electrode 80 and a drain electrode 90 are connected to the parts of the wiring 55 and wiring 56 that are exposed from the insulating film 54, respectively, as described below.

[0040] An insulating film 54 covering conductive layers such as a gate electrode 53, wiring 55, and wiring 56 is provided on one surface 50a of the device substrate 50. The device substrate 50 has a step on its surface 50a due to the arrangement of conductive layers such as the gate electrode 53. As shown in FIG. 5B, graphene 30 is transferred onto the surface 50a of the device substrate 50 (the insulating film 54 provided on the surface 50a) having such a step. For example, the graphene 30 is transferred onto the device substrate 50 by the method shown in FIGS. 2A to 2C, i.e., by floating the graphene 30 held by a resist layer 40 on a liquid surface 100a, scooping it up with the device substrate 50, and then removing the resist layer 40 after a heat treatment. This results in the formation of a structure 3 as shown in FIG. 5B (corresponding to the structure 3 in FIG. 2C). The graphene 30 is transferred onto the surface 50a of the device substrate 50 in such a way that it conforms to the steps formed by the conductive layers such as the gate electrode 53 .

[0041] The graphene 30 transferred to the device substrate 50 is patterned by etching, leaving a predetermined arrangement region of the graphene 30, as shown in Fig. 5(C). For example, the graphene 30 can be patterned by the method shown in Figs. 3(A) to 3(C) above, that is, by covering a portion of the transferred graphene 30 with a resist layer 60, performing etching using the resist layer 60 as a mask, and then removing the resist layer 60. As a result, a structure 4 (corresponding to structure 4 in Fig. 3(C)) as shown in Fig. 5(C) is formed.

[0042] To increase the sensitivity of the graphene optical sensor 1, antidots 31 are formed on the graphene 30 as shown in FIG. 5(D). EB lithography is used to form the antidots 31 on the graphene 30. For example, the method shown in FIG. 3(D) and FIGS. 4(A) to 4(C) above can be used. That is, a resist layer 70 covering the graphene 30 is subjected to EB exposure and development to form openings 71, the graphene 30 is etched using the resist layer 70 as a mask, and then the resist layer 70 is removed. By this method, the antidots 31 are formed on the graphene 30. As a result, a structure 5 as shown in FIG. 5(D) (corresponding to the structure 5 in FIG. 4(C)) is formed.

[0043] As shown in FIGS. 6(A) and 6(B), a source electrode 80 and a drain electrode 90 are formed on the ends of the graphene 30 on which the antidots 31 are formed. For convenience, the insulating films 52 and 54 shown in FIG. 6(A) are omitted from FIG. 6(B). As shown in FIGS. 6(A) and 6(B), a portion of the source electrode 80 is connected to the graphene 30, and another portion is connected to a wiring 55 exposed from the insulating film 54. As shown in FIGS. 6(A) and 6(B), a portion of the drain electrode 90 is connected to the graphene 30, and another portion is connected to a wiring 56 exposed from the insulating film 54. The source electrode 80 and the drain electrode 90 are formed on the surface 50a of the device substrate 50 so as to follow steps formed by the gate electrode 53, the wiring 55, and the wiring 56, as shown in FIG. 6(A).

[0044] In this manner, graphene 30 having antidots 31, a source electrode 80, and a drain electrode 90 are formed on a device substrate 50 having a step, and a graphene optical sensor 1 as shown in Figures 6(A) and 6(B) is manufactured.

[0045] In the graphene optical sensor 1, a predetermined bias is applied to the back-gate semiconductor substrate 51, the source electrode 80, and the drain electrode 90, and a current flows from the drain electrode 90 to the source electrode 80 through the graphene 30. The half-gate gate electrode 53 is used to adjust the threshold of the graphene 30. When light such as infrared light is received at a portion of the graphene 30 between the drain electrode 90 and the source electrode 80, the current flowing between the drain electrode 90 and the source electrode 80 changes in accordance with a change in the electrical conductivity of the graphene 30 or a change in the resistance between the drain electrode 90 and the source electrode 80 due to the received light. This change in current is detected, and the graphene optical sensor 1 detects light.

[0046] Although FIG. 6(B) shows an example in which a plurality of antidots 31 having a planar circular shape are arranged on the graphene 30, antidots 31 having various planar shapes, sizes, numbers and arrangements may be formed on the graphene 30.

[0047] When graphene 30 having antidots 31 is formed on a device substrate 50 having steps, it is preferable to use EB lithography as described above. 7A to 7D are diagrams illustrating an example of a method for forming graphene having antidots on a device substrate having a step. Each of Fig. 7A to Fig. 7D is a schematic cross-sectional view of a main part of an example of a process for forming graphene having antidots on a device substrate having a step.

[0048] 7(A) to 7(D) schematically show how graphene 30 having antidots 31 is formed on a step formed on a device substrate 50 due to a gate electrode 53. FIGS. 7(A) to 7(D) show the steps (including intermediate steps) from FIGS. 5(C) to 5(D) above.

[0049] The graphene 30 transferred to the device substrate 50 is patterned so as to be provided in a predetermined arrangement region, thereby obtaining a state as shown in FIG. 7(A) (corresponding to the structure 4 in FIG. 5(C)). The graphene 30 is provided so that a portion thereof faces the gate electrode 53 via the insulating film 54. The graphene 30 is provided on the surface 50a side of the device substrate 50 so as to climb up on a step formed by the gate electrode 53.

[0050] A resist layer 70 is formed on the surface 50a of the device substrate 50 so as to cover the graphene 30 thus formed. The formed resist layer 70 is then subjected to EB exposure and development, thereby forming a resist layer 70 having openings 71 as shown in FIG. 7(B). The graphene 30 is etched using the resist layer 70 having the openings 71 as a mask, thereby forming graphene 30 having antidots 31 as shown in FIG. 7(C). After etching the graphene 30, the resist layer 70 is removed, thereby obtaining a state as shown in FIG. 7(D) (corresponding to the structure 5 in FIG. 5(D)).

[0051] When EB lithography is used to form the opening 71 in the resist layer 70 shown in FIG. 7(B), it becomes possible to form the opening 71 in the resist layer 70 while suppressing the influence of steps on the device substrate 50.

[0052] That is, if a step exists in the device substrate 50, a step will also be formed in the graphene 30 formed thereon. As a result, a step may also be formed in the resist layer 70 formed on such graphene 30, or the resist layer 70 may be formed with a different film thickness above and below the step. Even in such cases, EB lithography can suppress the effects of the step in the graphene 30 or the resist layer 70, or the uneven film thickness of the resist layer 70, and form a plurality of openings 71 in the resist layer 70 with reduced variation in opening size. Therefore, a plurality of antidots 31 with a predetermined opening size and reduced variation in opening size can be formed in the graphene 30 that is etched using the resist layer 70 having such a plurality of openings 71 as a mask.

[0053] However, while the method using EB lithography can pattern the resist layer 70 and the graphene 30 while suppressing the influence of steps on the device substrate 50 as described above, it takes a relatively long time for EB exposure. Therefore, it takes a relatively long time to pattern the resist layer 70, i.e., to form the openings 71 by EB exposure and development, and as a result, it may not be possible to efficiently form the graphene 30 having the antidots 31. As described above, the method using EB lithography takes time to pattern the resist layer 70 and does not efficiently obtain the graphene 30 having the antidots 31, which may reduce the manufacturing efficiency and mass productivity of the graphene optical sensor 1 including such graphene 30.

[0054] In view of the above, the graphene optical sensor 1 is efficiently manufactured using a method as will be described below as an embodiment. [First embodiment] Figures 8 to 12 are diagrams illustrating an example of a method for manufacturing the graphene optical sensor according to the first embodiment. Figures 8(A) to 8(C), 9(A) to 9(C), 10(A) to 10(C), 11(A) to 11(C), and 12(A) to 12(D) each show a schematic cross-sectional view of a main part of an example of a manufacturing process for the graphene optical sensor according to the first embodiment.

[0055] First, a growth substrate 10 is prepared, having a catalytic metal layer 20 provided on one surface 10a, as shown in Fig. 8(A). The growth substrate 10 is, for example, a sapphire substrate. The metal layer 20 is, for example, copper. In this case, the copper of the metal layer 20 is provided on the surface 10a of the growth substrate 10 so that the surface 20a opposite to the growth substrate 10 is a (111) plane.

[0056] After preparing a growth substrate 10 provided with a catalytic metal layer 20, graphene 30 is grown on a surface 20a of the metal layer 20, as shown in FIG. 8(B). The graphene 30 is grown by a CVD method using a hydrocarbon such as methane as a carbon source. The graphene 30 may also be grown using a condensed polycyclic aromatic hydrocarbon as a precursor.

[0057] After the growth of the graphene 30, as shown in FIG. 8(C), a resist layer 40 is formed on the side of the graphene 30 opposite to the metal layer 20 and the growth substrate 10. The resist layer 40 functions to mask the graphene 30 to be etched as described below, and to hold the graphene 30 in place when it is separated from the growth substrate 10. For example, PMMA is used for the resist layer 40. At the stage of the process shown in FIG. 8(C), the resist layer 40 is formed in an uncured state that is not completely cured, for example, in a liquid or semi-cured state.

[0058] After the resist layer 40 is formed, the resist layer 40 is patterned by imprinting (or nanoimprinting) as shown in FIGS. 9(A) to 9(C). In patterning the resist layer 40 by imprinting, a mold 200 (die) as shown in FIG. 9(A) is prepared. The mold 200 is provided with protrusions 201 corresponding to antidots to be formed in the graphene 30. Various substrate materials such as a semiconductor substrate, a glass substrate, a ceramic substrate, a metal substrate, and a resin substrate can be used for the mold 200. The mold 200 is formed by forming openings in a resist layer formed on the substrate material using a photolithography technique or EB lithography, and then etching the substrate material using the resist layer with the openings formed as a mask. Recesses 202 are formed in the etched portions of the substrate material, and protrusions 201 are formed in the unetched portions, thereby forming the mold 200 as shown in FIG. 9(A).

[0059] As shown in FIG. 9(A), the prepared mold 200 is positioned so that the surface on which the convex portion 201 is provided faces the uncured resist layer 40 that covers the graphene 30 grown on the metal layer 20 provided on the growth substrate 10.

[0060] 9(B), the mold 200 is pressed against the uncured resist layer 40, so that the convex portions 201 of the mold 200 are pressed into the resist layer 40, and the resist layer 40 is pressed into the concave portions 202 of the mold 200. From this state, heating, for example, heating of the mold 200, is performed, and the resist layer 40 is cured.

[0061] 9(C), the mold 200 is separated from the resist layer 40, thereby obtaining the resist layer 40 in which openings 41 are formed in the portions of the mold 200 corresponding to the convex portions 201, i.e., the portions where the antidots of the graphene 30 are to be formed. In order to facilitate separation of the mold 200 from the resist layer 40, a release material having low adhesion to the resist layer 40 may be provided on at least the surface of the mold 200 on which the convex portions 201 are provided.

[0062] The graphene 30 is grown on the surface 20a of the metal layer 20 provided on the growth substrate 10 and has good flatness. A resist layer 40 is formed on the graphene 30 with such good flatness. Because the graphene 30 underlying the resist layer 40 has good flatness, openings 41 for forming antidots in the graphene 30 can be formed in the resist layer 40 by imprinting rather than EB lithography, which is less affected by unevenness in the underlying surface. Because the graphene 30 underlying the resist layer 40 has good flatness, even by imprinting, the openings 41 can be formed while suppressing variations in opening size due to unevenness in the underlying surface. Because the openings 41 can be formed in the resist layer 40 by imprinting rather than EB lithography, the openings 41 for forming antidots in the graphene 30 can be formed efficiently in a relatively short time.

[0063] 9(A) to 9(C), i.e., by imprinting, a resist layer 40 having openings 41 at locations corresponding to antidots to be formed in graphene 30 is formed. An example of the state of the resist layer 40 having openings 41 after being formed by imprinting is shown in FIG.

[0064] After forming the resist layer 40 having the openings 41 by imprinting, as shown in FIG. 10(B), the graphene 30 in the openings 41 is selectively removed by etching using the resist layer 40 as a mask. For example, the graphene 30 in the openings 41 of the resist layer 40 is removed by dry etching such as RIE using a gas containing oxygen. As a result, antidots 31 are formed in the graphene 30.

[0065] In this method, the openings 41 in the resist layer 40 for forming such antidots 31 in the graphene 30 are formed by imprinting, not by EB lithography. Therefore, the time required to obtain the graphene 30 having the antidots 31 is reduced compared to when EB lithography is used.

[0066] After the antidots 31 of the graphene 30 are formed, the metal layer 20 used for growing the graphene 30 is removed, as shown in FIG. 10(C). For example, the copper metal layer 20 is selectively removed by wet etching using an aqueous iron nitrate solution. By removing the metal layer 20, the graphene 30 with the antidots 31 formed thereon is separated from the growth substrate 10 while being held by the resist layer 40 having openings 41.

[0067] The graphene 30 separated from the growth substrate 10 by removing the metal layer 20 and the resist layer 40 holding it are transferred to a device substrate 50, for example, as shown in FIGS. 11(A) to 11(C).

[0068] The device substrate 50 includes a semiconductor substrate 51 that functions as a back gate, an insulating film 52 that functions as a back gate insulating film, a gate electrode 53 that functions as a half gate, and an insulating film 54 that functions as a half gate insulating film. The insulating film 52 is provided on the surface of the semiconductor substrate 51, and the gate electrode 53 is provided between the insulating film 52 and the insulating film 54. Although not shown here, the device substrate 50 may further include wiring 55 and wiring 56 interposed between the insulating film 52 and the insulating film 54, as shown in FIG. 5(A) above. The device substrate 50 may have a step on one surface 50a thereof that is formed due to the arrangement of conductive layers such as the gate electrode 53.

[0069] When the graphene 30 separated from the growth substrate 10 and the resist layer 40 holding it are transferred to the device substrate 50, for example, as shown in FIG. 11(A), the graphene 30 held by the resist layer 40 is floated on a liquid 100 such as water (its liquid surface 100a). At this time, the graphene 30 held by the resist layer 40 is floated on the liquid surface 100a so that the graphene 30 faces the liquid surface 100a. Then, the graphene 30 held by the resist layer 40 and floating on the liquid surface 100a is scooped up on the surface 50a of the device substrate 50 on which the gate electrode 53, the insulating film 54, and the like are formed.

[0070] 11(B), that is, a structure 6 in which graphene 30 supported by the resist layer 40 is laminated on the surface 50a side of the device substrate 50. The obtained structure 6 is subjected to a heat treatment. This heat treatment is performed for the purpose of evaporating and removing the liquid 100 remaining on the surface of the structure 6 and between the device substrate 50 and the graphene 30, and fixing the graphene 30 to the device substrate 50.

[0071] Antidots 31 are formed on the graphene 30 scooped up from the liquid surface 100a by the device substrate 50. The graphene 30 is held by the resist layer 40 having openings 41 communicating with the antidots 31. Therefore, when the graphene 30 is scooped up from the liquid surface 100a, the liquid 100 that has entered between the graphene 30 and the device substrate 50 easily escapes into the antidots 31 of the graphene 30 and the openings 41 of the resist layer 40.

[0072] When the structure 6 obtained by scooping up the graphene 30 and the resist layer 40 holding it from the liquid surface 100a with the device substrate 50 is subjected to a heat treatment, the liquid 100 remaining on the surface of the structure 6, including the antidots 31 and the inside of the openings 41, is removed by evaporation. During the heat treatment, the liquid 100 remaining between the device substrate 50 and the graphene 30 is also removed by evaporation. At this time, since the antidots 31 are formed in the graphene 30, the liquid 100 remaining between the device substrate 50 and the graphene 30 is likely to escape in a liquid or gas state from the antidots 31 to the outside through the openings 41.

[0073] When the antidots 31 are not formed on the graphene 30 (FIG. 2(B)), the liquid 100 remaining between the device substrate 50 and the graphene 30 travels a relatively long distance to the outer edge of the graphene 30, which is prone to escape to the outside, and escapes to the outside. In contrast, when the antidots 31 are formed on the graphene 30 (FIG. 11(B)), the liquid 100 remaining between the device substrate 50 and the graphene 30 travels a relatively short distance to the outer edge of the graphene 30 or the antidots 31, which are prone to escape to the outside. Therefore, when the antidots 31 are formed on the graphene 30 in this way, the liquid 100 remaining between the device substrate 50 and the graphene 30 is easily removed.

[0074] When the antidots 31 are formed on the graphene 30, the liquid 100 remaining between the device substrate 50 and the graphene 30 can be easily removed, and therefore, it is possible to suppress the remaining contaminant components (the liquid 100 and components in the liquid 100) between the device substrate 50 and the graphene 30. This makes it possible to favorably fix the graphene 30 to the device substrate 50. Furthermore, when the antidots 31 are formed on the graphene 30, the liquid 100 remaining between the device substrate 50 and the graphene 30 can be easily removed, and therefore, it is possible to shorten the time for the heat treatment and lower the temperature for the heat treatment.

[0075] After the heat treatment, the resist layer 40 is removed as shown in Fig. 11(C). For example, the PMMA resist layer 40 is selectively removed by wet etching using an organic solvent. This results in a structure 7 as shown in Fig. 11(C), i.e., a structure 7 in which graphene 30 having antidots 31 is stacked on the surface 50a side (insulating film 54 provided on the surface 50a) of the device substrate 50 on which the gate electrode 53, insulating film 54, etc. are formed.

[0076] After the structure 7 is formed, as shown in FIG. 12(A), a resist layer 60 is formed on the side of the graphene 30 on which the antidots 31 are formed, opposite the device substrate 50. The resist layer 60 is made of, for example, PMMA. The resist layer 60 is applied in a liquid state, then solidified by pre-baking, and patterned. The resist layer 60 also penetrates into the antidots 31. For example, photolithography is used to pattern the resist layer 60. The exposed portions (including those in the antidots 31) are removed during development. The resist layer 60 is formed so as to cover the arrangement area of ​​the graphene 30 in the graphene optical sensor.

[0077] After the resist layer 60 is formed, as shown in Fig. 12(B), a portion of the graphene 30 on which the antidots 31 are formed is selectively removed by etching using the resist layer 60 as a mask. For example, a portion of the graphene 30 is removed by dry etching such as RIE using a gas containing oxygen.

[0078] After etching the graphene 30, the resist layer 60 is removed. This results in a structure 8 as shown in Fig. 12(C), i.e., a structure 8 in which the graphene 30 on which the antidots 31 are formed is patterned in an arrangement region of the graphene optical sensor. The graphene 30 is arranged in a region in which a portion thereof faces the gate electrode 53 with the insulating film 54 interposed therebetween.

[0079] After the structure 8 is formed, as shown in FIG. 12(D), a source electrode 80 and a drain electrode 90, which are electrode layers, are formed on the ends of the graphene 30 on which the antidots 31 are formed. The source electrode 80 and the drain electrode 90 are made of a metal material such as gold. The source electrode 80 and the drain electrode 90 are each connected to the ends of the graphene 30. The source electrode 80 and the drain electrode 90 are connected to the ends of the graphene 30 so that the gate electrode 53 is located between them.

[0080] As described above, by the steps shown in Figures 8(A) to 8(C), 9(A) to 9(C), 10(A) to 10(C), 11(A) to 11(C), and 12(A) to 12(D), a graphene optical sensor 1 having the configuration shown in Figure 12(D) is manufactured.

[0081] In the method for manufacturing the graphene optical sensor 1 according to the first embodiment, graphene 30 is grown on a catalytic metal layer 20 provided on a growth substrate 10, a resist layer 40 is formed on the graphene 30, and openings 41 are formed in the resist layer 40 by imprinting. Then, the graphene 30 is etched using the resist layer 40 with the openings 41 formed therein as a mask, thereby forming antidots 31 in the graphene 30. The graphene 30 with the antidots 31 formed in this way is transferred to a device substrate 50 including a back-gate semiconductor substrate 51 and a half-gate gate electrode 53 (gate portion), and a source electrode 80 and a drain electrode 90 connected to the graphene 30 are formed.

[0082] As described above, in the manufacturing method of the graphene optical sensor 1 according to the first embodiment, imprinting is used to form the openings 41 in the resist layer 40 for forming the antidots 31 in the graphene 30. Because the graphene 30 grown on the metal layer 20 of the growth substrate 10 has good flatness, the openings 41 can be formed in the resist layer 40 formed thereon by imprinting, without relying on EB lithography, which is less affected by steps in the underlying layer. By using imprinting, the openings 41 in the resist layer 40 can be efficiently formed with reduced variation in opening size. This shortens the time required to obtain the graphene 30 having the antidots 31, and improves the manufacturing efficiency and mass productivity of the graphene optical sensor 1.

[0083] On the other hand, in the case of a method of forming antidots 31 after transferring graphene 30 grown on a catalytic metal layer 20 provided on a growth substrate 10 to a device substrate 50 having steps (FIGS. 1 to 7), EB lithography is used. That is, openings 71 for forming antidots 31 of graphene 30 are formed in a resist layer 70 formed on the graphene 30 by EB lithography, which is less affected by steps in the underlying layer. EB lithography makes it possible to form the openings 71 in the resist layer 70 while suppressing the effect of steps in the device substrate 50. However, in the method using EB lithography, EB exposure takes a relatively long time, which may reduce the manufacturing efficiency and mass productivity of the graphene optical sensor 1.

[0084] In contrast, in the method of the first embodiment, openings 41 are formed by imprinting in the resist layer 40 covering the graphene 30 on the growth substrate 10 before transfer to the device substrate 50, and antidots 31 are formed by etching using the openings 41 as a mask. This eliminates the need for EB lithography and makes it possible to efficiently manufacture the graphene optical sensor 1 including the graphene 30 having antidots 31.

[0085] [Second embodiment] Fig. 13 is a diagram illustrating an example of a method for manufacturing the graphene optical sensor according to the second embodiment. Fig. 13(A) to Fig. 13(C) each show a schematic cross-sectional view of a main part of an example of a manufacturing process of the graphene optical sensor according to the second embodiment.

[0086] In the method for manufacturing the graphene optical sensor 1 of the second embodiment, the steps up to those shown in Figures 8(A) to 8(C), 9(A) to 9(C), and 10(A) to 10(C) described in the first embodiment can be the same. As shown in Figure 10(C) above, the graphene 30 on which the antidots 31 are formed is separated from the growth substrate 10 while being held by a resist layer 40 having openings 41. Thereafter, in this second embodiment, the graphene 30 is transferred to a device substrate 50 by steps such as those shown in Figures 13(A) to 13(C).

[0087] First, as shown in FIG. 13(A), a solvent 110 is applied to the surface 50a of the device substrate 50 on which the gate electrode 53, the insulating film 54, etc. are formed. An organic solvent can be used as the solvent 110. A non-polar solvent can be used as the solvent 110. A low-boiling-point solvent with a relatively low boiling point can be used as the solvent 110. For example, heptane (CH3(CH2)5CH3) is used as the solvent 110. The predetermined solvent 110 is applied to the surface 50a of the device substrate 50 by using a method such as dropping, coating, or spraying. Alternatively, the device substrate 50 may be immersed in the predetermined solvent 110 to have the solvent 110 applied to the surface 50a.

[0088] As shown in FIG. 13(B), graphene 30 held by a resist layer 40 is placed on the surface 50a of the device substrate 50 on which the solvent 110 has been provided. The placed graphene 30 and the resist layer 40 holding it are obtained in the step of FIG. 10(C) above, with openings 41 formed in the resist layer 40 and antidots 31 formed in the graphene 30 at the positions of the openings 41 in the resist layer 40. Such graphene 30 and resist layer 40 are placed on the solvent 110 provided on the surface 50a of the device substrate 50 so that the graphene 30 faces the solvent 110, as shown in FIG. 13(B).

[0089] 11(A), a solvent 110 may be used as the liquid 100, and the graphene 30 and the resist layer 40 floating in the solvent 110 may be scooped up on the surface 50a side of the device substrate 50, thereby obtaining the state shown in FIG. 13(B).

[0090] After the graphene 30 and the resist layer 40 are placed on the surface 50a of the device substrate 50 via the solvent 110, a heat treatment is performed. The heat treatment evaporates and removes the solvent 110. This results in a structure 9 as shown in FIG. 13(C), i.e., a structure 9 in which the graphene 30 held by the resist layer 40 is transferred onto the surface 50a side of the device substrate 50.

[0091] When a non-polar solvent is used as the solvent 110, the formation of wrinkles in the graphene 30 is suppressed when the graphene 30 (and the resist layer 40) is placed thereon (FIG. 13(B)) and when the solvent 110 is removed by heat treatment (FIG. 13(C)). Furthermore, the formation of cracks in the graphene 30 due to wrinkles is suppressed. Wrinkles and cracks formed in the graphene 30 may cause a decrease in the performance of the graphene optical sensor 1. Therefore, suppressing the formation of wrinkles and cracks in the graphene 30 is effective in achieving a high-performance graphene optical sensor 1.

[0092] Furthermore, if a low-boiling-point solvent is used as the solvent 110, the solvent 110 can be evaporated relatively easily when the solvent 110 is removed by heat treatment ( FIG. 13(C) ). This reduces the amount of solvent 110 remaining between the device substrate 50 and the graphene 30 after the heat treatment. This reduces the amount of contaminant components (the solvent 110 and components in the solvent 110) remaining between the device substrate 50 and the graphene 30, making it possible to favorably fix the graphene 30 to the device substrate 50.

[0093] After the structure 9 is formed, the steps of Fig. 11(C) and Fig. 12(A) to Fig. 12(D) described in the first embodiment are performed. That is, after the resist layer 40 is removed (Fig. 11(C)), the graphene 30 is patterned by etching using the resist layer 60 as a mask (Figs. 12(A) to 12(C)), and the source electrode 80 and the drain electrode 90 connected to the graphene 30 are formed (Fig. 12(D)). In this way, the graphene optical sensor 1 is manufactured.

[0094] The first and second embodiments have been described above. Part of the manufacturing process of the graphene optical sensor 1 in the first and second embodiments is further shown in Fig. 14. Fig. 14(A) to Fig. 14(E) each show a schematic cross-sectional view of a main part of an example of the manufacturing process.

[0095] 14(A), in the above-described method shown as an embodiment, graphene 30 is grown on a surface 20a of a metal layer 20 provided on a surface 10a of a growth substrate 10, the surface 20a being opposite to the growth substrate 10. Then, a resist layer 40 is formed on the side of the grown graphene 30 opposite to the metal layer 20, and openings 41 are formed in the resist layer 40 by imprinting.

[0096] 14(B), the graphene 30 is etched using the resist layer 40 with the openings 41 formed therein as a mask to form the graphene 30 having the antidots 31. For example, the antidots 31 are formed in the graphene 30 at the openings 41 of the resist layer 40 by dry etching using a gas containing oxygen.

[0097] 14(C), the metal layer 20 is removed, and the graphene 30 held by the resist layer 40 is separated from the growth substrate 10. For example, the metal layer 20 between the graphene 30 and the growth substrate 10 is removed by wet etching, thereby separating the graphene 30 held by the resist layer 40 from the growth substrate 10.

[0098] 14(D), the graphene 30 separated from the growth substrate 10 and the resist layer 40 holding the graphene 30 are transferred to a device substrate 50. For example, the graphene 30 and the resist layer 40, which are floated so that the graphene 30 faces the liquid surface 100a, are scooped up by the device substrate 50, and a heat treatment is performed, thereby transferring the graphene 30 held by the resist layer 40 to the device substrate 50. Alternatively, a solvent 110 is provided on the device substrate 50, and the graphene 30 and the resist layer 40 are placed thereon so that the graphene 30 faces the solvent 110, and a heat treatment is performed, thereby transferring the graphene 30 held by the resist layer 40 to the device substrate 50.

[0099] Next, as shown in FIG. 14(E), the resist layer 40 is removed from the graphene 30 transferred to the device substrate 50. In the above method, a resist layer 40 with openings 41 formed by imprinting is formed on graphene 30 grown on the metal layer 20 of the growth substrate 10 before transfer to the device substrate 50, and antidots 31 are formed by etching using the resist layer 40 as a mask. After the antidots 31 are formed in the graphene 30, the graphene 30 is transferred to the device substrate 50. Therefore, unlike the case where antidots 31 are formed in the graphene 30 by forming an etching mask by EB lithography, which is less affected by steps after transfer to the device substrate 50, EB lithography is not required to form the antidots 31. Eliminating the need for EB lithography to form the antidots 31 in the graphene 30 makes it possible to efficiently manufacture a graphene optical sensor 1 including graphene 30 having antidots 31.

[0100] Note that antidots 31 of various planar shapes, sizes, numbers, and arrangements, i.e., patterns in which some carbon atoms are missing, can be formed in the graphene 30. Openings 41 in the resist layer 40 for forming various patterns of the graphene 30 can be formed by imprinting.

[0101] The above-described method shown as an embodiment is not limited to the formation of antidots 31 in a region inside the outer edge of graphene 30, but can also be applied to the formation of antidots 31 on the outer edge of graphene 30, patterning for defining the outer edge of graphene 30, and the like.

[0102] The following additional notes are provided regarding the above-described embodiment. (Supplementary Note 1) A step of growing graphene on a side of a metal layer provided on a first surface of a first substrate, the side being opposite to the first substrate; forming a resist layer on the side of the graphene opposite the metal layer; forming a pattern in the resist layer by imprinting; etching the graphene using the resist layer on which the pattern has been formed as a mask; A method for manufacturing a graphene optical sensor, comprising:

[0103] (Appendix 2) The method for producing a graphene optical sensor according to appendix 1, wherein the resist layer is made of polymethyl methacrylate. (Supplementary Note 3) The step of forming the pattern in the resist layer includes the step of forming the pattern by imprinting to form antidots in which carbon atoms are missing in the graphene, 3. The method for manufacturing a graphene optical sensor according to claim 1, wherein the step of etching the graphene includes a step of forming the antidots in the graphene by etching using the resist layer on which the pattern is formed as a mask.

[0104] (Appendix 4) The method for manufacturing a graphene optical sensor according to any one of Appendices 1 to 3, further comprising the steps of removing the metal layer and separating the graphene held by the resist layer from the first substrate after the step of etching the graphene.

[0105] (Appendix 5) A method for producing a graphene optical sensor according to appendix 4, comprising the step of transferring the graphene held by the resist layer to a second surface of a second substrate. (Appendix 6) The method for manufacturing a graphene optical sensor according to appendix 5, wherein the second substrate has a step on the second surface to which the graphene held by the resist layer is transferred.

[0106] (Supplementary Note 7) The second substrate is a semiconductor substrate; a first insulating film laminated on the semiconductor substrate; a conductive layer laminated on a portion of the first insulating film; a second insulating film laminated on the first insulating film and the conductive layer; and the second insulating film is provided on the second surface of the second substrate, 7. The method for manufacturing a graphene optical sensor according to claim 5, wherein the graphene held by the resist layer is transferred to the second insulating film on the second surface.

[0107] (Supplementary Note 8) The step of transferring the graphene held by the resist layer to the second surface of the second substrate includes: floating the graphene held by the resist layer on the liquid surface so that the graphene faces the liquid surface; scooping up the graphene held by the resist layer, which is floated on the liquid surface, on the second surface side of the second substrate; 8. A method for producing a graphene optical sensor according to any one of claims 5 to 7, comprising:

[0108] (Supplementary Note 9) The step of transferring the graphene held by the resist layer to the second surface of the second substrate includes: applying a solvent to the second surface of the second substrate; placing the graphene supported by the resist layer in the solvent so that the graphene faces the solvent; removing the solvent between the graphene held by the resist layer and the second surface of the second substrate; 8. A method for producing a graphene optical sensor according to any one of claims 5 to 7, comprising:

[0109] (Appendix 10) The method for producing a graphene optical sensor according to appendix 9, characterized in that a non-polar solvent is used as the solvent. (Appendix 11) The method for manufacturing a graphene optical sensor according to any one of Appendices 5 to 10, further comprising the step of removing the resist layer from the graphene transferred to the second surface of the second substrate.

[0110] (Appendix 12) A method for manufacturing a graphene optical sensor according to appendix 11, comprising forming an electrode layer on the second surface side of the second substrate, the electrode layer being connected to the graphene from which the resist layer has been removed. [Explanation of symbols]

[0111] 1. Graphene optical sensor 2,3,4,5,6,7,8,9 structure 10 Growth substrate 10a,20a,50a side 20 metal layer 30 Graphene 31 Antidot 40,60,70 resist layer 41,71 Opening 50 Device substrates 51 Semiconductor substrate 52,54 Insulating film 53 Gate electrode 55,56 Wiring 80 Source electrode 90 Drain electrode 100 liquid 100a liquid level 110 Solvent 200 molds 201 Convex 202 recess

Claims

1. growing graphene on a side of a metal layer disposed on a first surface of a first substrate opposite the first substrate; forming a resist layer on the side of the graphene opposite the metal layer; forming a pattern in the resist layer by imprinting; etching the graphene using the resist layer on which the pattern is formed as a mask; removing the metal layer after the step of etching the graphene, and separating the graphene held by the resist layer from the first substrate; A method for manufacturing a graphene optical sensor, comprising:

2. the step of forming the pattern in the resist layer includes the step of forming the pattern by imprinting to form antidots in which carbon atoms are missing in the graphene, 2. The method for manufacturing a graphene optical sensor according to claim 1, wherein the step of etching the graphene includes a step of forming the antidots in the graphene by etching using the resist layer on which the pattern is formed as the mask.

3. The method for manufacturing a graphene optical sensor according to claim 1 or 2, further comprising the step of transferring the graphene held by the resist layer to a second surface of a second substrate.

4. The method for manufacturing a graphene optical sensor according to claim 3 , wherein the second substrate has a step on the second surface to which the graphene held by the resist layer is transferred.

5. The second substrate is a semiconductor substrate; a first insulating film laminated on the semiconductor substrate; a conductive layer laminated on a portion of the first insulating film; a second insulating film laminated on the first insulating film and the conductive layer; and the second insulating film is provided on the second surface of the second substrate, The method for manufacturing a graphene optical sensor according to claim 3 or 4, wherein the graphene held by the resist layer is transferred to the second insulating film on the second surface.

6. The step of transferring the graphene held by the resist layer to the second surface of the second substrate includes: floating the graphene held by the resist layer on the liquid surface so that the graphene faces the liquid surface; scooping up the graphene held by the resist layer, which is floated on the liquid surface, on the second surface side of the second substrate; The method for manufacturing a graphene optical sensor according to any one of claims 3 to 5, comprising:

7. The step of transferring the graphene held by the resist layer to the second surface of the second substrate includes: applying a solvent to the second surface of the second substrate; placing the graphene supported by the resist layer in the solvent so that the graphene faces the solvent; removing the solvent between the graphene held by the resist layer and the second surface of the second substrate; The method for manufacturing a graphene optical sensor according to any one of claims 3 to 5, comprising:

8. The method for manufacturing a graphene optical sensor according to any one of claims 3 to 7, further comprising the step of removing the resist layer from the graphene transferred to the second surface of the second substrate.

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