Graphene device and method for producing same

Abstract

To provide a graphene device having an intermediate layer that achieves both flatness and phonon reduction and improved mobility of a graphene layer.SOLUTION: A graphene device 1 includes a laminated film including an inorganic insulating layer 3 on a semiconductor substrate 2, a phonon blocking layer 4, and a graphene layer 5. The phonon blocking layer 4 is composed of a mixed film of an inorganic material containing a metal element and an organic material containing a metal element. As a result, the phonon blocking layer 4 becomes an intermediate layer having a configuration in which the phonon blocking effect of the organic material and the flatness of the inorganic material are compatible, and the mobility in the graphene layer 5 is improved as compared with the conventional one.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a graphene device in which graphene is used as a functional layer, and a method for producing the same. [Background technology]

[0002] Graphene, a one-atom-thick sheet structure in which carbon atoms are arranged in a hexagonal lattice, has been studied for its high mobility and its application to various devices such as transistors and Hall sensors. Hereinafter, various devices using graphene as a functional layer are referred to as "graphene devices." Examples of graphene devices include those described in Patent Document 1.

[0003] The graphene device described in Patent Document 1 is a graphene transistor with a bottom-gate / top-contact structure in which a gate insulating layer, a graphene layer, and source / drain electrodes are formed in that order on a silicon substrate, with the graphene layer functioning as a channel layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5697069 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, a structure in which an intermediate layer is interposed between an insulating layer and a graphene layer has been investigated to improve the mobility of the graphene layer. This intermediate layer is thought to improve the mobility of the graphene layer by reducing phonons from the insulating layer containing Si or the like and improving the surface smoothness of the insulating layer. For example, CR Dean, Nature Nanotechnology 5, 722 (2010) reported that the mobility of the graphene layer was improved in a structure in which a graphene layer was formed on an intermediate layer formed by mechanical peeling using single crystal h-BN.

[0006] However, for example, A. Dankert et al., Scientific Reports 7, 15231 (2017) reported that in the case of an h-BN intermediate layer formed by chemical vapor deposition (CVD), which is a mass-production method, no improvement in the mobility of the graphene layer could be confirmed.

[0007] The present inventors have conducted extensive research into graphene devices in which an intermediate layer is formed by a mass-production method and the mobility of the graphene layer is improved. Specifically, the inventors have conducted research into configurations in which an intermediate layer is provided by a method such as CVD, which is made of an inorganic material such as Al2O3 or h-BN, or an organic material such as a self-assembled monolayer (SAM) or AlCHO. However, in either case, the improvement in the mobility of the graphene layer could not be confirmed. This result is believed to be due to the fact that when the intermediate layer is made of an inorganic material, flatness can be ensured but the phonon reduction effect is low, and when the intermediate layer is made of an organic material, the phonon reduction effect can be expected but the flatness cannot be ensured.

[0008] In view of the above, an object of the present invention is to provide a graphene device having an intermediate layer that achieves both flatness and phonon reduction and has improved mobility in the graphene layer, and a method for manufacturing the same. [Means for solving the problem]

[0009] In order to achieve the above object, the graphene device described in claim 1 is a graphene device comprising a semiconductor substrate (2) and a laminated film formed on the semiconductor substrate and including an inorganic insulating layer (3), a phonon blocking layer (4), and a graphene layer (5), wherein the phonon blocking layer is sandwiched between the graphene layer and the inorganic insulating layer and is a mixed film of an inorganic material (41) having a metal element and an organic material (42) having a metal element.

[0010] In this graphene device, a phonon blocking layer is interposed between the inorganic insulating layer and the graphene layer, and the phonon blocking layer is a mixed film of an inorganic material containing a metal element and an organic material. As a result, the phonon blocking layer is composed of a mixed film of an inorganic material and an organic material, and by achieving both the phonon reduction effect of the organic material and the flatness of the inorganic material, the mobility of the graphene layer is improved compared to conventional methods.

[0011] The method for producing a graphene device described in claim 11 is a method for producing a graphene device in which a laminated film consisting of an inorganic insulating layer (3), a phonon blocking layer (4) and a graphene layer (5) is formed on a semiconductor substrate (2), and includes the steps of preparing a semiconductor substrate, forming a graphene layer on the semiconductor substrate, forming an inorganic insulating layer on the semiconductor substrate, and forming a phonon blocking layer on the semiconductor substrate at a position between the graphene layer and the inorganic insulating layer, and in forming the phonon blocking layer, an atomic layer deposition method is used to form the phonon blocking layer consisting of a mixed film of an inorganic material (41) having a metal element and an organic material (42) having a metal element.

[0012] In this method for manufacturing a graphene device, a phonon blocking layer interposed between an inorganic insulating layer and a graphene layer is formed by atomic layer deposition as a mixed film of an inorganic material having a metal element and an organic material. A phonon blocking layer that combines the phonon reduction effect of the organic material with the flatness of the inorganic material can be formed, and a graphene device can be manufactured in which the mobility of the graphene layer is improved compared to conventional methods.

[0013] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of a graphene device according to an embodiment. [Diagram 2] FIG. 1 is a diagram showing the configuration of a sample for measuring the mobility of a graphene layer. [Diagram 3] FIG. 13 is a diagram showing the mobility measurement results of a graphene layer in a sample of a comparative example. [Figure 4] FIG. 2 is a schematic diagram showing a case where an intermediate layer is made of only an inorganic material. [Diagram 5] FIG. 13 is a schematic diagram showing a case where an intermediate layer is made of only an organic material. [Figure 6] FIG. 13 is a schematic diagram showing a case where the intermediate layer is formed of a mixed film of an inorganic material and an organic material. [Figure 7] 13A and 13B are diagrams showing the results of measuring the mobility and surface roughness of the graphene layer in samples in which the mixture ratio of the inorganic material and the organic material in the phonon blocking layer is changed. [Figure 8] 1 is a schematic diagram showing the charge state of a phonon blocking layer when the metal elements of the inorganic material and the organic material are different. FIG. [Figure 9] 3 is a schematic diagram showing the surface roughness of a phonon blocking layer when the metal elements of the inorganic material and the organic material are different. FIG. [Figure 10] FIG. 11 is a cross-sectional view showing another configuration example of the graphene device according to the embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing another configuration example of the graphene device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0016] (Embodiment) A graphene device 1 according to an embodiment will be described. The graphene device 1 is suitable for application to various devices utilizing the high mobility of the graphene layer 5 described below, for example, a magnetic sensor such as a transistor or a Hall sensor. In this specification, a case in which the graphene device 1 is applied to a transistor will be described as a representative example, but the present invention is not limited to this example.

[0017] As shown in FIG. 1, for example, a graphene device 1 includes a semiconductor substrate 2, an inorganic insulating layer 3, a phonon blocking layer 4, a graphene layer 5, a first electrode 6, and a second electrode 7, and can be a graphene transistor with a bottom-gate / top-contact structure.

[0018] The semiconductor substrate 2 is made of a semiconductor material such as Si (silicon) or SiC (silicon carbide), and may be a silicon wafer or a SiC wafer obtained by a known method. When the graphene device 1 has a bottom gate / top contact structure, the semiconductor substrate 2 has a gate electrode (not shown) formed on one surface thereof and the gate electrode is covered with an inorganic insulating layer 3.

[0019] In the case of a graphene transistor, the inorganic insulating layer 3 functions as a gate insulating layer and is made of an inorganic insulating material such as SiO2 or Al2O3. For example, when the semiconductor substrate 2 is a Si substrate, the inorganic insulating layer 3 is made of SiO2, and is obtained by thermally oxidizing the Si substrate, but is not limited to this. For example, the inorganic insulating layer 3 is formed on one surface of the semiconductor substrate 2 by a film formation method such as CVD or atomic layer deposition (ALD), and may be made of SiO2 or other known inorganic insulating materials.

[0020] The phonon blocking layer 4 is, for example, an intermediate layer located between the inorganic insulating layer 3 and the graphene layer 5, and is sandwiched between these two layers while being in contact with each other. When the phonon blocking layer 4 is located closer to the semiconductor substrate 2 than the graphene layer 5, it may also be called an "underlayer". The phonon blocking layer 4 is, for example, laminated on the inorganic insulating layer 3, and serves to reduce surface roughness such as Ra, that is, to improve flatness. The phonon blocking layer 4 also functions as a phonon reduction layer that suppresses, for example, the propagation of phonons from the inorganic insulating layer 3 to the graphene layer 5, thereby preventing the mobility of the graphene layer 5 from decreasing. In other words, the phonon blocking layer 4 is configured to ensure flatness and reduce phonons at the same time.

[0021] The phonon blocking layer 4 is a mixed film of an inorganic material 41 having a metal element, which will be described later, and an organic material 42 having a metal element. The phonon blocking layer 4 is an organic-inorganic hybrid film in which the inorganic material 41 and the organic material 42 are mixed, and thus has both the property of improving flatness due to the inorganic material 41 and the property of reducing phonons due to the organic material 42. The phonon blocking layer 4 is formed by ALD, and is formed by repeatedly forming a film of the inorganic material 41 and a film of the organic material 42 according to the ratio of the inorganic material 41 and the organic material 42. Details of the phonon blocking layer 4 will be described later.

[0022] The inorganic material 41 is, for example, an oxide or nitride of a metal element such as Al, Hf (hafnium), or Zr (zirconium). It is believed that the mobility of graphene is determined by the balance between surface phonon scattering and impurity diffusion. For example, when the underlayer of graphene is made of Al2O3 or AlN, it is expected that the phonon blocking effect is particularly high (for example, A. Konar, et al., Phys. Rev. B 82, 115452 (2010)). In addition, since films containing Al are used in various devices, are highly suitable for mass production, and the composition ratio can be easily controlled in the film formation process by ALD, it is preferable that the inorganic material 41 is an oxide or nitride of Al.

[0023] The organic material 42 is composed of an organometallic material in which organic molecules having an alkyl group, an aldehyde group, or the like are bonded to a metal element such as Al. The organic material 42 is, for example, AlCHO, and is preferably configured to have the same metal element as the inorganic material 41. This will be described later.

[0024] The graphene layer 5 is a layer made of graphene, which is a one-atom sheet structure in which carbon atoms are arranged in a hexagonal lattice and bonded together, and can be formed, for example, by forming a film on another catalyst substrate or the like by CVD and then transferring it. Specifically, for example, a single layer or multiple layers (multiple atomic layers) of graphene are grown on an arbitrary catalyst substrate such as Cu, Fe (iron), Ni, etc., by CVD using a hydrocarbon gas such as methane or ethylene as a raw material. Thereafter, the catalyst substrate is dissolved by a wet process to extract only the graphene. Then, this graphene is transferred onto the phonon blocking layer 4. For example, the graphene layer 5 made of a single layer or multiple layers of graphene is formed through the above-mentioned steps.

[0025] In this formation process, the number of graphene layers is determined mainly by the supply amount of source gas and the growth time, and therefore, by optimizing these, it is possible to produce the graphene layer 5 with high accuracy. In addition, the number of graphene layers grown by CVD can be confirmed by a technique such as Raman spectroscopy.

[0026] When the graphene device 1 is configured as a transistor, for example, the graphene layer 5 is a single-layer graphene of one atom and functions as a carrier layer. Note that the graphene layer 5 is not limited to a single-layer graphene, and may be an n-graphene layer in which n (n≧2) single-layer graphenes are stacked, and the thickness of the graphene layer 5 may be appropriately changed depending on the application of the graphene device 1.

[0027] The first electrode 6 and the second electrode 7 function as a source electrode and a drain electrode, and have a laminated structure in which, for example, Ti (titanium) / Au (gold) are laminated in this order from the graphene layer 5 side. In addition to the above-mentioned materials, any conductive material such as Ni (nickel), Cr (chromium), Pt (platinum), Cu (copper), Al (aluminum), Ag (silver), Pd (palladium), and ITO (indium tin oxide) may be used for the first electrode 6 and the second electrode 7. The first electrode 6 and the second electrode 7 are formed by a vacuum film formation method such as a deposition method, and are arranged parallel to each other on the graphene layer 5 with a space between them.

[0028] The above is the basic configuration of the graphene device 1 when used as a transistor. The graphene device 1 can be obtained, for example, by preparing a silicon substrate as the semiconductor substrate 2, forming an inorganic insulating layer 3 by thermal oxidation, forming a phonon blocking layer 4 by ALD, laminating a graphene layer 5 by CVD and transfer, and forming electrodes 6 and 7 by vapor deposition.

[0029] [Phonon blocking layer] Next, the configuration and effects of the phonon blocking layer 4 will be described.

[0030] The present inventors fabricated an evaluation sample in which an inorganic insulating layer 3, an intermediate layer 10, and a graphene layer 5 were laminated in this order on a semiconductor substrate 2, as shown in FIG.

[0031] In the evaluation sample, for example, a pair of electrodes (not shown) arranged in parallel at a predetermined distance apart is formed on the graphene layer 5, and the mobility of the graphene layer 5 is measured by evaluating electrical characteristics using the pair of electrodes. In addition, in the evaluation sample, the semiconductor substrate 2 is a Si substrate, the inorganic insulating layer 3 is SiO2 obtained by thermally oxidizing the Si substrate, the graphene layer 5 is a monolayer of graphene formed by ALD, and the intermediate layer 10 is made of an inorganic material, an organic material, or a mixed film of these.

[0032] First, when the intermediate layer 10 is made of SiO2, the evaluation sample has a mobility of about 1200 cm of the graphene layer 5, as shown in FIG. 2 / Vs, and no significant improvement in mobility was observed. This is thought to be because when the intermediate layer 10 is made only of inorganic materials, as shown in FIG. 4, the intermediate layer 10 becomes a dense film and the flatness is improved, but the effect of reducing phonons is low.

[0033] On the other hand, when the intermediate layer 10 is formed of a SAM film made of an organic material having a metal element, the mobility of the graphene layer 5 of the evaluation sample is about 1470 cm 2 The SAM film was, for example, but not limited to, OTMS (octadecyltrimethoxysilane, CH3(CH2) 17 An organic silane-based SAM film such as Si(OCH3)3) or a carboxylic acid-based SAM film can be used. The thickness of the SAM film in this evaluation sample was approximately 2 nm. The evaluation sample in which the intermediate layer 10 was a SAM film had a slightly higher mobility of the graphene layer 5 than the SiO2 sample, but no significant improvement was observed. This result is probably due to the fact that while the phonon reduction effect was improved by making the intermediate layer 10 only from an organic material, the structure of the intermediate layer 10 became unstable, as shown in FIG. 5, for example, and flatness could not be obtained.

[0034] Therefore, as a result of intensive investigations by the present inventors, the present invention has been devised in which intermediate layer 10 is formed of a mixed film of an inorganic material and an organic material, and while obtaining the phonon reduction effect by using the organic material, the inorganic material is also used to ensure flatness and improve the mobility of graphene layer 5. For example, as shown in Fig. 6, it was thought that by having a configuration having a portion made of an organic material having a metal element and a portion made of an inorganic material having a metal element, intermediate layer 10 can be obtained that can achieve both the phonon reduction effect by organic molecules and flatness due to the denseness of the inorganic material.

[0035] Next, using AlO as the inorganic material and AlCHO as the organic material, (AlO) (100-X)(AlCHO) X A number of evaluation samples were fabricated in which the intermediate layer 10 was made of a film having the above composition. The mobility of the graphene layer 5 was measured for a number of evaluation samples in which the value of X was changed within the range of 0 to 100. The results are shown in FIG. 7. Note that in these evaluation samples, the intermediate layer 10 was configured to have a thickness of 5 nm.

[0036] When X=0, that is, when the intermediate layer 10 is composed of only AlO, the mobility of the graphene layer 5 in the evaluation sample is approximately 1280 cm 2 / Vs, which was slightly higher than that of SiO2.

[0037] On the other hand, when X=100, that is, when the intermediate layer 10 is composed of only AlCHO, the mobility of the graphene layer 5 in the evaluation sample is about 1380 cm 2 / Vs, which was slightly lower than that in the case of using the SAM film.

[0038] In addition, the mobility of the graphene layer 5 in the evaluation sample is approximately 1250 cm when X=16. 2 / Vs.

[0039] However, when X=50, the mobility of the graphene layer 5 in the evaluation sample is approximately 1680 cm 2 / Vs. In addition, when X=83.3, the mobility of the graphene layer 5 in the evaluation sample was about 2300 cm 2 / Vs. When X=50 and 83, a significant improvement was observed compared to when X=100 (only inorganic material) and X=0 (only organic material). This is believed to be the result of intermediate layer 10 being formed as a mixed film of inorganic material and organic material, and by controlling the composition ratio, it functions as a phonon blocking layer that combines the phonon reduction effect of the organic material with the flatness of the inorganic material.

[0040] In this way, by interposing the phonon blocking layer 4 composed of a mixed film of an inorganic material and an organic material between the inorganic insulating layer 3 and the graphene layer 5, it is possible to improve the mobility of the graphene layer 5.

[0041] 7, the surface roughness Rq (unit: nm) of the graphene layer 5 was measured for each sample with X=0, 83.3, 91, and 100, and was 0.34 nm, 0.48 nm, 0.54 nm, and 1.34 nm, respectively. Since the cause of the decrease in mobility of the graphene layer 5 in the case of the AlCHO only configuration is considered to be the deterioration of flatness described above, it is expected that the effect of improving the mobility will be obtained in the case of X=91 where flatness is maintained, similar to the case of X=83.3.

[0042] Therefore, the phonon blocking layer 4 is (AlO) (100-X) (AlCHO) X In this case, it is expected that the effect of improving the mobility in graphene layer 5 can be obtained so long as X is at least within the range of greater than 50 and less than 91. In other words, in this case, it is considered that phonon blocking layer 4 has a configuration in which both the phonon blocking effect and flatness are achieved when the AlO content is greater than about 9% and less than 50%.

[0043] The composition ratio in the phonon blocking layer 4 can be controlled by adjusting the number of ALD film formation steps of the inorganic material and the organic material according to the composition ratio of the inorganic material and the organic material. For example, (AlO) 16.7 (AlCHO) 83.3 When the composition ratio is set to 16.7:83.3, the ratio of AlO to AlCHO is approximately 1:5, so it is possible to control the ratio by, for example, performing 5 AlCHO film formation processes for one AlO film formation process. Also, in the evaluation sample, the thickness of the phonon blocking layer 4 was set to 5 nm, but when composed of a SAM film, a slight increase in mobility was confirmed even at a thickness of 2 nm, so it is expected that the same effect will be obtained if the phonon blocking layer 4 is at least 2 nm thick.

[0044] In the phonon blocking layer 4, the metal element in the inorganic material is A, and the metal element in the organic material is B. When the metal elements A and B are different, as shown in FIG. 8, for example, a region of non-uniform charge may occur on the film surface due to the difference in valence between A and B. In this case, the graphene layer 5 may have a reduced mobility due to Coulomb scattering of graphene electrons caused by the region of non-uniform charge in the phonon blocking layer 4. In addition, when the atomic sizes of the metal elements A and B are significantly different, the phonon blocking layer 4 may have an increased surface roughness due to the difference in atomic sizes, as shown in FIG. 9, for example, which may cause a reduction in mobility in the graphene layer 5. From these viewpoints, it is preferable that the metal element A in the inorganic material and the metal element B in the organic material in the phonon blocking layer 4 are the same.

[0045] In the graphene device 1 according to the embodiment, a phonon blocking layer 4 is interposed between an inorganic insulating layer 3 and a graphene layer 5, and the phonon blocking layer 4 is made of a mixed film of an inorganic material having a metal element and an organic material. The phonon blocking layer 4 is configured to achieve both the flatness of the inorganic material and the phonon reduction effect of the organic material. Therefore, the graphene device 1 has an effect that the mobility of the graphene layer 5 is improved by the phonon blocking layer 4 compared to the conventional case. In addition, since the phonon blocking layer 4 can be formed by ALD, which is highly mass-producible, the graphene device 1 has a structure with reduced manufacturing costs.

[0046] (Modification) The graphene device 1 according to the embodiment is not limited to an example having a laminate in which an inorganic insulating layer 3, a phonon blocking layer 4, and a graphene layer 5 are laminated in this order from the semiconductor substrate 2 side, and the configuration of the laminate can be appropriately changed depending on the type of device, etc.

[0047] 10, the graphene device 1 may have a configuration in which the electrodes 6 and 7, the graphene layer 5, the phonon blocking layer 4, and the inorganic insulating layer 3 are laminated in this order on the semiconductor substrate 2, and the third electrode 8 is formed on the inorganic insulating layer 3. In this case, the graphene device 1 becomes a graphene transistor with a top-gate / bottom-contact structure in which the third electrode 8 is the gate electrode, the electrodes 6 and 7 are the source / drain electrodes, the graphene layer 5 is the channel layer, and the inorganic insulating layer 3 is the gate insulating layer.

[0048] 11, the graphene device 1 may have a laminated film in which an inorganic insulating layer 3, a phonon blocking layer 4, a graphene layer 5, and a phonon blocking layer 4 are laminated in this order on a semiconductor substrate 2, and electrodes 6 and 7 are arranged on both sides of the laminated film. In this case, the graphene device 1 is a magnetic Hall sensor in which the graphene layer 5 functions as a charge carrier transfer layer. The first electrode 6 has a two-layer structure, for example, a first layer 61 in contact with the laminated film and the inorganic insulating layer 3, and a second layer 62 laminated on the first layer 61. The second electrode 7 has a two-layer structure, for example, a first layer 71 in contact with the laminated film and the inorganic insulating layer 3, and a second layer 72 laminated on the first layer 71, similar to the first electrode 6. For example, the first layers 61 and 71 are made of Ti (titanium) / Cr (chromium), and the second layers 62 and 72 are made of Au.

[0049] That is, the graphene device 1 may have a configuration in which the phonon blocking layer 4 is interposed between the inorganic insulating layer 3 and the graphene layer 5. For example, when the inorganic insulating layer 3 is located closer to the semiconductor substrate 2 than the graphene layer 5, the phonon blocking layer 4 is disposed under the graphene layer 5 to serve as an underlayer, and when the graphene layer 5 is located closer to the semiconductor substrate 2 than the inorganic insulating layer 3, the phonon blocking layer 4 serves as a covering layer that covers the graphene layer 5. In addition, when there are multiple inorganic insulating layers 3 and the layers are located on both sides of the graphene layer 5, the phonon blocking layers 4 are multiple, like the inorganic insulating layers 3, and are disposed above and below the graphene layer 5.

[0050] In this modification, the phonon blocking layer 4 can achieve both flatness and a phonon reduction effect, and contributes to improving the mobility of the graphene layer 5, so that the graphene device 1 can achieve the same effects as in the above embodiment.

[0051] (Other embodiments) The graphene device 1 shown in each of the above-mentioned embodiments is an example of the graphene device 1 of the present invention, and is not limited to each of the above-mentioned embodiments, and can be appropriately modified within the scope of the claims. For example, the graphene device 1 may be formed in various combinations or forms of one or all of the elements of each of the above-mentioned embodiments, within the possible scope.

[0052] For example, although the graphene device 1 is applied to a Hall sensor or a transistor in the above description, the present invention is not limited thereto, and the graphene device 1 may be applied to other devices. For example, the graphene device 1 may be configured as shown in FIG. 1 and may be a gas sensor in which the graphene layer 5 functions as a gas adsorption layer that adsorbs gas molecules such as NO2 and NH3. In this manner, the graphene device 1 may be applied to various sensors and the like that utilize the high mobility of the graphene layer 5. [Explanation of symbols]

[0053] 2. Semiconductor Substrate 3. Inorganic insulating layer 4 Phonon blocking layer 41 Inorganic materials 42 Organic materials 5 Graphene layers

Claims

1. 1. A graphene device comprising: A semiconductor substrate (2); A laminated film formed on the semiconductor substrate, the laminated film being composed of an inorganic insulating layer (3), a phonon blocking layer (4), and a graphene layer (5); The graphene device, wherein the phonon blocking layer is disposed in a position sandwiched between the graphene layer and the inorganic insulating layer, and is a mixed film of an inorganic material (41) having a metal element and an organic material (42) having a metal element.

2. The graphene device according to claim 1 , wherein the laminated film is configured by laminating the inorganic insulating layer, the phonon blocking layer, and the graphene layer in this order from the semiconductor substrate side.

3. The graphene device according to claim 1 , wherein the laminated film is configured such that the graphene layer, the phonon blocking layer, and the inorganic insulating layer are laminated in this order from the semiconductor substrate side.

4. The laminated film comprises at least two of the phonon blocking layers, the graphene layer is sandwiched between at least two of the phonon blocking layers; The graphene device of claim 1 , wherein the inorganic insulating layer is disposed in contact with one of the at least two phonon blocking layers.

5. The graphene device according to claim 1 , wherein the inorganic material constituting the phonon blocking layer is an oxide or nitride of the metal element.

6. The graphene device according to claim 1 , wherein the inorganic material and the organic material constituting the phonon blocking layer have the same metal element.

7. The graphene device according to claim 1 , wherein the phonon blocking layer is made of an inorganic material that is AlO and an organic material that is AlCHO.

8. The graphene device of claim 7 , wherein the phonon blocking layer has a content of the inorganic material in the range of greater than 9% and less than 50%.

9. The graphene device according to claim 1 , wherein the phonon blocking layer has a thickness of 2 nm or more.

10. The inorganic insulating layer is made of SiO ２ The graphene device according to claim 1 ,

11. A method for producing a graphene device in which a laminated film made of an inorganic insulating layer (3), a phonon blocking layer (4) and a graphene layer (5) is formed on a semiconductor substrate (2), comprising: providing the semiconductor substrate; forming the graphene layer on the semiconductor substrate; forming the inorganic insulating layer on the semiconductor substrate; forming the phonon blocking layer on the semiconductor substrate at a position between the graphene layer and the inorganic insulating layer; In forming the phonon blocking layer, the method for manufacturing a graphene device includes forming the phonon blocking layer from a mixed film of an inorganic material (41) having a metal element and an organic material (42) having a metal element by atomic layer deposition.

12. In forming the inorganic insulating layer, a silicon substrate is used as the semiconductor substrate, and SiO ２ The method for producing a graphene device according to claim 11 , further comprising forming

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