JP7102364B2 - Electronic elements and molecular detectors - Google Patents

Description

Embodiments relate to electronic devices and molecular detectors.

Graphene has high carrier mobility, and the entire structure of the two-dimensional sheet is exposed to the surroundings. Therefore, it is expected to realize an electronic element such as a molecule detection sensor that detects adsorbed target molecules with high sensitivity by using a base material having a graphene layer, or a molecule detection device using the molecule detection sensor.

Graphene is formed, for example, by stripping from graphite or by chemical vapor deposition (CVD). However, it has been difficult to mass-produce graphene having a desired carrier mobility by the conventional method.

Patent No. 5614484

Nature Communications 9, 1413 (2018)

An object to be solved by the present invention is to provide a base material having a graphene layer having high carrier mobility, and an electronic element and a molecule detection device using the graphene layer.

The electronic element of the embodiment includes a substrate and a plurality of single-domain graphene layers juxtaposed on the substrate, and the plurality of single-domain graphene layers are centered on the center point of the single-domain graphene layer in a plan view. It has a 3n rotationally symmetric shape (n is a natural number) , the plurality of single domain graphene layers have a crystal phase having a six-membered ring structure of carbon atoms, and the crystal phases of the plurality of single domain graphene layers have different directions from each other. Oriented to.

It is a top view which shows the structural example of the base material of embodiment. It is a top view which shows the other shape example of a single domain graphene layer. It is a top view which shows the other shape example of a single domain graphene layer. It is a top view which shows the other shape example of a single domain graphene layer. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a figure for demonstrating an example of the manufacturing method of the base material of an embodiment. It is a block diagram which shows the molecule detection apparatus. It is a block diagram which shows another example of a molecule detection apparatus. It is a figure which shows the detector in the molecule detection apparatus. It is a schematic diagram which shows the structural example of a GFP. It is a schematic diagram which shows the structural example of a GFP. It is a schematic diagram which shows the structural example of a GFP. It is a figure which shows an example of the detection waveform of an object by a molecule detection apparatus. It is a figure which shows an example of a plurality of detection cells by a molecule detection apparatus. It is a figure which shows an example of the detection result of the object by a plurality of detection cells. It is a figure which shows the information processing part in a molecule detection apparatus.

Hereinafter, embodiments will be described with reference to the drawings. In each embodiment, substantially the same constituent parts may be designated by the same reference numerals, and the description thereof may be partially omitted. The drawings are schematic, and the relationship between the thickness of each part and the plane dimensions, the ratio of the thickness of each part, etc. may differ from the actual constituent parts.

(Base material)
FIG. 1 is a schematic top view showing a structural example of the base material of the embodiment. The base material 100 shown in FIG. 1 includes a substrate 101 and a plurality of single domain graphene layers 102 juxtaposed on the substrate 101. In addition, juxtaposed means that they are arranged at intervals. For example, the plurality of single domain graphene layers 102 may be arranged in an array.

As the substrate 101, a substrate having an insulating film such as silicon oxide on a semiconductor substrate such as a silicon substrate can be used. The substrate 101 is not limited to this, and a glass substrate, a quartz substrate, or the like may be used as the substrate 101.

The single domain graphene layer 102 is a layer having graphene (single domain graphene) having a single crystal phase that does not contain grain boundaries between graphenes. Single domain graphene comprises a two-dimensional sheet-like crystalline phase having a six-membered ring structure of carbon atoms. The crystal phases of the plurality of single domain graphene layers 102 are oriented in different directions from each other. Single domain graphene has few grain boundaries and defects, and has high carrier mobility. Therefore, by using single domain graphene for an electronic element, for example, a very sensitive sensor can be realized. The carrier mobility of the single domain graphene layer 102 is preferably, for example, 10000 cm ² / Vs or more. By increasing the carrier mobility of the single domain graphene layer 102 to 10000 cm ² / Vs or more, it is possible to realize a high-performance electronic element by using, for example, the single domain graphene layer 102. Examples of high-performance electronic devices include a molecule detection sensor that detects adsorbed target molecules with high sensitivity.

Each of the plurality of single domain graphene layers 102 has a 3n rotationally symmetric shape (n is a natural number) centered on the center point C of the surface in a plan view. The plan view is a view from a direction perpendicular to the formation surface of the single domain graphene layer 102 on the substrate 101 (direction perpendicular to the paper surface of FIG. 1). The center point C is appropriately set according to the shape of the single domain graphene layer 102 in a plan view.

The single domain graphene layer 102 has a regular hexagonal shape in a plan view, for example, as shown in FIG. 1, but is not limited to this, and may have other 3n square shapes. 2 to 4 are schematic views showing other shape examples of the single domain graphene layer 102. The single domain graphene layer 102 shown in FIG. 2 has a triangular shape in a plan view. The single domain graphene layer 102 shown in FIG. 3 has a star-shaped hexagonal shape in a plan view. The single domain graphene layer 102 shown in FIG. 4 has a hexagonal shape in which the first side and the second side having a length different from the first side face each other in a plan view. The 3n rotationally symmetric shape is not limited to the regular 3n square shape, and includes, for example, a substantially regular 3n square shape having distortion or unevenness on at least one side of the regular 3n square shape.

The area of each of the plurality of single domain graphene layers 102 in a plan view is preferably, for example, 1 μm ² or more and 1000000 μm ² or less. By controlling the area of the single domain graphene layer 102 to 1 μm ² or more and 1000000 μm ² or less, it is possible to suppress the formation of grain boundaries between graphenes, so that it is possible to facilitate the formation of single domain graphene. The shortest distance between adjacent single domain graphene layers 102 is preferably, for example, 10 μm or more and 10000 μm or less. By controlling the shortest distance between adjacent single domain graphene layers 102 to 10 μm or more and 10000 μm or less, it is possible to suppress the formation of grain boundaries between graphenes, so that it is possible to facilitate the formation of single domain graphene. As a result, the productivity of the base material 100 can be improved.

Next, an example of a method for manufacturing the base material of the embodiment will be described. 5 to 14 are views for explaining an example of a method for manufacturing a base material according to an embodiment. An example of a method for producing a base material according to an embodiment includes a Cu—M alloy layer forming step, an annealing step, a graphene layer forming step, and a peeling / transfer step.

In the Cu—M alloy layer forming step, as shown in FIG. 5, a plurality of Cu—M alloy layers 104 juxtaposed on the substrate 103 are formed. For example, the plurality of Cu—M alloy layers 104 may be arranged in an array. The plurality of Cu-M alloy layers 104 are formed by forming a Cu-M alloy film by, for example, sputtering or a vapor deposition method, and etching a part of the Cu-M alloy film by using a photolithography technique.

As the substrate 103, it is preferable to use an inexpensive substrate, for example, a quartz substrate, a substrate having silicon oxide and a silicon substrate, a metal substrate, a ceramics substrate, or the like can be used. Since the photolithography technique is used to form the Cu—M alloy layer 104, the surface of the substrate 103 is preferably flat. Further, since annealing is performed to form the Cu—M alloy layer 104, it is preferable to use a substrate that is stable even at an annealing temperature. For example, a quartz substrate has a flat surface with a surface roughness of about 0.4 nm and is stable even when annealed at 1000 ° C.

The Cu—M alloy layer 104 has a function as a base layer for forming the single domain graphene layer 102. As shown in FIG. 6, the Cu—M alloy layer 104 has a polycrystalline structure having a plurality of crystal phases 104a and grain boundaries 104b. The shape of the Cu—M alloy layer 104 in a plan view is not particularly limited.

The Cu—M alloy layer 104 has an alloy compound containing a copper (Cu) element and an M element. The copper element is an element for allowing the Cu—M alloy layer 104 to function as a base layer, and the M element is an element for adjusting the distance between the closest atoms of the Cu—M alloy layer 104. When graphene is epitaxially grown on the Cu—M alloy layer 104, graphene grows along the crystal plane of the Cu—M alloy layer 104. Therefore, in order to form a single domain graphene, the distance between the closest atoms of the underlying layer Is preferably matched with the closest atom-to-atom distance of graphene. However, the interatomic distance of copper is different from the closest interatomic distance of graphene, and the in-plane interatomic distance of graphene is about 2.82 Å, but the closest interatomic distance of the (111) plane of copper is 2.56 Å. Is. Therefore, it is difficult to form single domain graphene by epitaxially growing graphene on the copper layer because the closest atomic distances do not match.

On the other hand, for example, by adding a metal element having a nearest atom-to-atom distance larger than 2.82 Å to copper at an arbitrary ratio, the crystal lattice size of the alloy can be approached to 2.82 Å. The compatibility of the tangent-atom distance can be improved, that is, it can be roughly matched with the nearest atom-to-atom distance of graphene. The closest atom-to-atom distance is controlled, for example, by adjusting the concentration of M element in the Cu—M alloy layer 104.

As the M element, a metal element in which the (111) plane of the face-centered cubic structure (fcc) having high compatibility with the six-membered ring structure of graphene and the (0001) plane of the hexagonal close-packed structure (hcp) are preferentially oriented. Is preferable. Further, it is preferable to have an alloy composition that does not melt or decompose at the graphene film formation temperature. In addition, it is preferable to select it in consideration of the expansion coefficient of the alloy and the graphene formation conditions.

Examples of the M element include gold (Au), magnesium (Mg), aluminum (Al), calcium (Ca), scandium (Sc), titanium (Ti), strontium (Sr), yttrium (Y), and zirconium (Zr). , Silver (Ag), Cadmium (Cd), Hafnium (Hf), Yttrium (Tl), and Lead (Pb) at least one element selected from the group. Gold is more preferable as the M element. The M element may be a combination of two or more kinds of elements.

The shortest distance between the adjacent Cu—M alloy layers 104 is preferably the same as the shortest distance between the adjacent single domain graphene layers 102, and is preferably 10 μm or more and 10,000 μm or less, for example.

In the annealing step, the Cu—M alloy layer 104 is annealed, for example, in a vacuum atmosphere or an inert gas atmosphere. As a result, the Cu—M alloy layer 104 having a polycrystalline structure is melted, the atoms are rearranged, and then cooled, whereby the Cu—M alloy layer 104 is recrystallized (single) as shown in FIGS. 7 and 8. It can be crystallized to form a Cu—M alloy layer 104 having a single crystal structure. The annealing temperature and time are appropriately set according to the desired single crystal structure.

The Cu—M alloy layer 104 after the annealing step has a 3n rotationally symmetric shape centered on the center point of the Cu—M alloy layer 104 in a plan view. Examples of the 3n rotationally symmetric shape include, but are not limited to, a regular hexagonal shape.

The single crystal structure preferably has a (111) plane of a face-centered cubic structure having a low surface energy and high compatibility with a six-membered ring structure of graphene, a (0001) plane of a hexagonal close-packed structure, and the like. The surface is located in the direction perpendicular to the surface of the substrate 103, and the in-plane direction is random. The area of the Cu—M alloy layer 104 after the annealing step in a plan view is designed in consideration of improving the mass productivity of electronic devices and the size required for device formation, and is generally 1 μm ² or more and 1000000 μm ² or less. By making it smaller, the degree of device integration and mass productivity can be improved, and it is easy to single crystallize at the time of annealing. Larger areas are more likely to generate domains and increase the likelihood that single-domain graphene will become multi-domain. The thickness of the Cu—M alloy layer 104 is not particularly limited as long as it has a size that facilitates single crystal formation during annealing, but is, for example, 10 nm or more and 1000 nm or less.

In the graphene layer forming step, as shown in FIG. 9, a plurality of single domain graphene layers 102 are formed by forming graphene on each of the plurality of single crystallized Cu—M alloy layers 104.

As a graphene film forming method, for example, a method of bringing the Cu—M alloy layer 104 into contact with a carbon raw material in a chamber using CVD is preferable. Examples of the carbon raw material include methane, ethane, ethylene, acetylene and the like, and two or more kinds of carbon raw materials may be used in combination.

As a condition for epitaxially growing graphene, for example, an inert gas or hydrogen gas may be supplied, and it is preferable to form a film at a film forming temperature of 500 ° C. or higher and 1200 ° C. or lower. The pressure in the chamber is preferably, for example, 1 × ^10-5 Pa or more and 1 × 10 ⁵ Pa or less. Before forming the graphene film, the object to be treated may be subjected to a treatment such as cleaning or annealing in advance. By forming a graphene film using CVD, the single domain graphene can be epitaxially grown to form the single domain graphene layer 102.

As shown in FIGS. 9 and 10, the graphene formed in a plan view has a 3n rotationally symmetric shape corresponding to the 3n rotationally symmetric shape of the Cu—M alloy layer 104 that functions as an underlayer. Further, the growth may proceed in the in-plane direction, and the single domain graphene layer 102 may be formed so as to protrude from the 3n rotationally symmetric shape of the Cu—M alloy layer 104. Also in this case, graphene has a 3n rotationally symmetric shape. Each of the single domain graphene layers 102 is preferably a single layer, but 90% or more of the single domain graphene layers 102 may be a single layer.

In the peeling / transfer step, the single domain graphene layer 102 is peeled from the Cu—M alloy layer 104, and the peeled single domain graphene layer 102 is transferred to the substrate 101. Since the single domain graphene layer 102 formed on the Cu—M alloy layer 104 is not chemically bonded to the Cu—M alloy layer 104, it can be easily peeled off and transferred to the substrate 101. Peeling methods include stamping with silicon rubber, etching of Cu-M alloy layer 104, peeling after coating with resin, separation method using reduction potential difference of Cu-M alloy layer 104, laser peeling, heating and cooling method, etc. Can be mentioned. Further, the polymer can be applied, dried, peeled off, and transferred to the substrate 101. Not limited to this, other transfer methods may be used as long as the single domain graphene is less likely to be contaminated, the shape is less likely to be broken such as torn, and the position of the single domain graphene layer 102 is less likely to deviate from the design position.

Further, a sacrificial layer for peeling off the single domain graphene layer 102 may be formed. Materials such as ceramics, compounds, and metals can be used as the sacrificial layer, but a material that can withstand the heat treatment temperature when forming the Cu—M alloy layer or the single domain graphene layer 102 and can be dissolved, decomposed, and removed by etching or the like. It is preferable to use.

In an example of the peeling / transfer step, as shown in FIG. 11, the resin layer 105 is formed on the substrate 103 so as to cover the plurality of Cu—M alloy layers 104. After that, as shown in FIG. 12, the support substrate 106 is adhered to the opposite surface of the adhesive surface of the substrate 103 of the resin layer 105. Then, as shown in FIG. 13, the resin layer 105 is peeled off from the substrate 103 and the Cu—M alloy layer 104 is peeled off from the single domain graphene layer 102. Then, as shown in FIG. 14, the peeled single domain graphene layer 102 is transferred to the substrate 101.

Further, an electronic element can be formed by forming an electrode on the single domain graphene layer 102. Further, by modifying the surface of the single domain graphene layer 102 with a functional group or the like, it is possible to produce a chemical sensor that can impart responsiveness to a specific gas and can detect even an extremely low concentration gas.

As described above, in the example of the method for producing a base material of the embodiment, a single crystal Cu—M alloy layer having a distance between closest atoms suitable for forming single domain graphene is formed on a substrate, and a Cu—M alloy is formed. Graphene is epitaxially grown on the layer.

Examples of conventional methods for forming single-layer graphene include a method of peeling from graphite with tape or the like. However, the above method has low mass productivity and is difficult to put into practical use. Another method is to grow graphene on a metal foil by the CVD method in order to produce a large-area single-layer graphene sheet. However, since single-layer graphene is generally formed in the form of a copper foil, the quality is in the crystalline state of copper. It depends on. Generally, the orientation of the copper metal foil is random, grain boundaries and surface irregularities occur, and the surface condition is not uniform. Moreover, since the distance between the closest atoms of the copper crystal and the distance between the closest atoms of graphene do not match, the graphene layer has grain boundaries and defects when graphene is grown on the copper surface. This causes the carrier mobility of the graphene layer.

As another example of the conventional graphene forming method, for example, a method of epitaxially growing a metal layer such as copper on a single crystal sapphire substrate and growing graphene on the surface thereof can be mentioned. However, since the desired carrier mobility cannot be obtained, the sapphire substrate is expensive, and the size is limited to the wafer shape, mass productivity is low.

As another example of the conventional graphene forming method, there is a method of observing a single-layer exfoliated graphene from graphite randomly scattered on a substrate with a camera, determining the shape, and transferring the graphene in the manner of a stamp. However, it has problems such as shape variation and installation loss. Further, in this method, since the single-layer exfoliated graphene is observed and transferred one by one, the mass productivity is low.

On the other hand, in the method for producing a base material of the embodiment, a plurality of single domain graphene layers can be formed in the same step. Further, since the number of patterning steps after the formation of the single domain graphene layer can be reduced and the contamination of the single domain graphene layer can be suppressed, graphene having a desired carrier mobility can be easily formed. Therefore, it is possible to increase the mass productivity of graphene having a desired carrier mobility.

(Molecular detector)
The base material can be applied to, for example, a molecule detection device. FIG. 15 is a block diagram showing the molecule detection device of the embodiment. The molecule detection device 1 shown in FIG. 15 is, for example, a device that detects a target molecule 2 from a target gas 3 generated from a gas generation source, and includes a detector 10 and a classifier 20. The target gas 3 containing the target molecule 2 is first sent to the detector 10 of the molecule detection device 1. Here, the target gas 3 may contain a substance having a molecular weight, a molecular structure, or the like similar to the target molecule 2 as an impurity. Further, as shown in FIG. 16, the target molecule 2 floating in the air often exists in a state of being mixed with various impurities 4 (4a, 4b) such as an odor component and fine particles. From such a point, as shown in FIG. 16, the target gas 3 may be sent to the detector 10 of the molecule detection device 1 after being pretreated by the filter device 5 or the molecule distribution device 6 in advance.

As the filter device 5 of the pretreatment devices, a general medium-high performance filter or the like is used. In the filter device 5, particulate matter such as fine particles contained in the target gas 3 is removed. The target gas 3 from which the particulate matter has been removed by the filter device 5 is sent to the molecular partitioning device 6. As the molecular distributor 6, the target gas 3 is ionized into an ionized substance group, a voltage is applied to the ionized substance group to fly at a speed proportional to the mass, and the flight speed due to this mass difference and the flight time based on the flight speed are used. Then, an apparatus for separating the ionized substance of the target molecule 2 from the ionized substance group is exemplified. As such a molecular distribution device 6, a device including an ionization unit, a voltage application unit, and a flight time separation unit is used.

The target gas 3 containing the target molecule 2 is guided to the detector 10 either directly or after being pretreated by a device such as a filter device 5 or a molecule distribution device 6. The detector 10 comprises the base material 100 of the embodiment, and the base material 100 includes a detection surface partitioned into a plurality of detection cells 111 as shown in FIG. Note that FIG. 17 shows a state in which the detection surface 10A of the detector 10 is arranged toward the end 6a of the molecular distribution device 6, but the arrangement of the detector 10 is not limited to this. Each of the plurality of detection cells 111 includes a sensor 11 and a detection element 13 having an organic probe 12 provided on the sensor 11. FIG. 17 shows a detection element 13 using a graphene field effect transistor (GFFT) for the sensor 11. The sensor 11 is not limited to the FET, and may be a field effect transistor using carbon nanotubes, a surface acoustic wave sensor, or the like.

The GFET has a semiconductor substrate 101a having a function as a gate electrode, a substrate 101 having an insulating film 102b having a function as a gate insulating layer on the gate electrode, and a function as a channel forming region on the gate insulating layer 15. The single domain graphene layer 102 is provided with a source electrode 17 connected to the single domain graphene layer 102, and a drain electrode 18 connected to the single domain graphene layer 102. The gate electrode is superimposed on the single domain graphene layer 102 and used as a back gate. The source electrode 17 or the drain electrode 18 may be formed by using, for example, gold (Au). Further, the source electrode 17 or the drain electrode 18 may be formed by depositing titanium (Ti), chromium (Cr) or the like by several nm for the purpose of improving the adhesion to the gate insulating layer 15.

An organic probe 12 is provided on the single domain graphene layer 102. As the organic substance probe 12, an organic compound that selectively binds to the target molecule 2 is used. The target molecule 2 guided to the detector 10 is captured by the organic probe 12 on the single domain graphene layer 102. Some impurities cannot interact with the organic probe 12 and are not captured by the detection element 13. Electrical detection is performed by the movement of electrons from the target molecule 2 captured by the organic probe 12 to the FET. As a result, the target molecule 2 of interest is selectively detected.

18 to 20 are schematic views showing a structural example of a FET. The FET shown in FIG. 18 is provided with a source electrode 17 and a drain electrode 18 so as to overlap diagonally with the single domain graphene layer 102 having a regular hexagonal shape in a plan view. The FET shown in FIG. 19 is provided with a source electrode 17 and a drain electrode 18 so as to overlap the opposite sides of the regular hexagonal single domain graphene layer 102 in a plan view. The FET shown in FIG. 20 is provided with a source electrode 17 and a drain electrode 18 so as to overlap one side of the single domain graphene layer 102 having a regular triangular shape in a plan view and diagonally thereof.

Since the organic substance constituting the organic substance probe 12 has a property of being soluble in a solvent, the organic substance probe 12 can be installed on the single domain graphene layer 102 by applying it as a solution dissolved in a solvent. The organic probe 12 preferably has a site having a structure like a pyrene ring in order to facilitate interaction with graphene. Molecules with a structure like a pyrene ring interact with a hexagonal π-electron system composed of graphene carbon and form an interaction state called so-called π-π stacking. When low-concentration probe molecules are dissolved in a solvent and applied to graphene, π-π stacking is formed between the pyrene ring and graphene, and the probe molecules are aligned and immobilized on the graphene. The organic probe 12 can be placed on the single domain graphene layer 102 by utilizing such a self-arrangement action.

When the target molecule 2 is captured by the organic probe 12 provided on the single domain graphene layer 102, the output of the FETC changes. Since graphene is a single layer and has a zero gap, electricity normally continues to flow between the source electrode 17 and the drain electrode 18. When the gate insulating layer 15 has a dielectric constant of about that of a silicon oxide film, electricity often continues to flow between the source electrode 17 and the drain electrode 18.

The target molecule 2 that has flown in the vicinity of the organic probe 12 is attracted to the organic probe 12 by the force of hydrogen bonding and, in some cases, comes into contact with the organic probe 12. When the target molecule 2 comes into contact with the organic probe 12, electrons are exchanged with the organic probe 12 to transmit an electrical change to the single domain graphene layer 102 in contact with the organic probe 12. The electrical change transmitted from the organic probe 12 to the single domain graphene layer 102 disturbs the flow of electricity between the source electrode 17 and the drain electrode 18, so that the FETF functions as a sensor 11.

According to the FETF using the single domain graphene layer 102, even a very slight electric change appears as a remarkable output. Therefore, the highly sensitive detection element 13 can be configured. Since graphene has the property of a zero-gap semiconductor in the sensor 11 using the GFET, there is a tendency for a current to flow between the source electrode 17 and the drain electrode 18 without applying a voltage to the gate electrode. Although it functions as a sensor 11 as it is, normally, a current is passed between the source electrode 17 and the drain electrode 18 with a voltage applied to the gate electrode, and the gate electrode when the target molecule 2 is captured by the organic probe 12 Observe electrical changes.

FIG. 21 shows an example of the detection waveform of the target molecule 2 by the molecule detection device 1. When the organic probe 12 captures the target molecule 2, the detected waveform changes as shown in FIG. 21. Various methods can be considered for converting the detected waveform into the signal intensity. For example, a value calculated from the areas of P1 and P2 in FIG. 21 and P3 which is the tip of the peak is set as the intensity. However, the method is not always limited to this method.

In the detection of the target molecule 2 by the detection element 13 described above, the higher the movement of electrons from the target molecule 2 captured by the organic probe 12, the higher the function as the sensor 11. The sensor 11 using a FET is considered to be the most sensitive FET sensor, and the sensitivity can be improved by about 3 times as compared with the sensor using carbon nanotubes. Therefore, by using the detection element 13 in which the GFP and the organic probe 12 are combined, highly sensitive detection of the target molecule 2 becomes possible.

FIG. 22 shows a hexagonal grid-like sensor in which the detection surface 10A of the detector 10 is divided into six detection cells, that is, detection cell A, detection cell B, detection cell C, detection cell D, detection cell E, and detection cell F. ing. At least a part of the detection cells A to F is provided with an organic probe 12 having a functional group of a different type, that is, a plurality of organic probes 12 having different binding strengths with the target molecule 2. The plurality of organic probes 12 interact with the target molecule 2 respectively, but since the binding strength with the target molecule 2 is different, detection signals having different strengths are output. The signal intensities of the detection signals from the detection cells A to F differ depending on the binding strength of the organic probe 12 with the target molecule 2.

The signals detected in the detection cells A to F are sent to the classifier 20 for signal processing. The classifier 20 converts the detection signals from the detection cells A to F into intensities, and analyzes a signal pattern (for example, a pattern of six detection signals shown in FIG. 23) based on the intensity difference of these detection signals. The classifier 20 stores signal patterns corresponding to the substances to be detected, and by comparing these signal patterns with the signal patterns detected in the detection cells A to F, the target detected by the detector 10 is stored. The molecule 2 is identified. Such signal processing is referred to here as a pattern recognition method. According to the pattern recognition method, the target molecule 2 can be detected and identified by a signal pattern peculiar to the object, for example, as in a fingerprint test. Therefore, it is possible to selectively and highly sensitively detect a gas component (target molecule 2) having an extremely low concentration on the order of ppt to ppb.

By applying the pattern recognition method described above, it is possible to selectively and highly sensitively detect and identify the target molecule 2 even when impurities are mixed in the target gas 3 guided to the detector 10. can. Further, since the signal patterns detected in the detection cells A to F differ depending on the type of the target molecule 2, by applying the pattern recognition method, even if impurities having similar molecular weights and similar constituent elements are mixed. , The substance to be detected can be selectively and highly sensitively detected.

The detection and identification results of the target molecule 2 obtained by the molecule detection device 1 may be transmitted and utilized via the information network. FIG. 24 is provided with an information processing unit 30 having at least one selected from a function of transmitting the detection information of the target molecule 2 via the information network and a function of collating the detection information with the reference information acquired from the information network. The in-house molecular detection device 1 is shown. The information processing unit 30 includes an information transmitting unit 31 that transmits the detection information of the target molecule 2, an information receiving unit 32 that receives the reference information, and an information collating unit 33 that collates the detected information with the reference information. .. The information processing unit 30 may have only one of an information transmission function and an information reception and collation function.

The detection information of the target molecule 2 is transmitted from the information transmission unit 31 to the information user via the network N. Further, in order to collate the detection information of the target molecule 2 with the existing reference information, the reference information is acquired by the information receiving unit 32 via the network N. The acquired reference information is collated with the detection information by the information collation unit 33. By acquiring and referencing information from the external network N, the function of carrying and analyzing a large amount of information can be replaced with the outside, so that the molecule detection device 1 can be miniaturized and portability can be improved. Further, by using the network N, it is possible to immediately acquire a new signal pattern in the pattern recognition method. The side receiving the information can take the next action based on this information. The portable molecule detection device 1 can be arranged in various places, and the obtained data can be collected and analyzed from various places to be useful for evacuation guidance in an abnormal situation. By combining the network N and the molecule detection device 1, many uses that could not be achieved in the past are created, and the industrial value is improved.

According to the molecule detection device 1 of the embodiment, it is possible to selectively and highly sensitively detect gas component molecules having an extremely low concentration on the order of ppt to ppb. Further, the molecule detection device 1 can be miniaturized by increasing the detection sensitivity and the detection accuracy by the detector 10 and the discriminator 20. Therefore, it becomes possible to provide the molecule detection device 1 having both portability and detection accuracy.

(Example 1)
A ceramic layer having a thickness of about 20 nm was formed on a 100 mm square quartz substrate, and a plurality of circular Cu—Au alloy layers having a diameter of 10 μm having a composition ratio of Au: Cu = 4: 1 were formed using photolithography technology. After annealing in a hydrogen atmosphere at 1000 ° C. for 3 hours in an electric furnace, the mixture was slowly cooled. When taken out, the Cu—Au alloy layer had a regular hexagonal shape in plan view. From the Low Energy Electron Diffraction (LED) image, six spots lined up at equal intervals or slightly wider were confirmed, and it was found that the Cu—Au alloy layer had a single crystal structure. Spots were seen in the Cu-Au alloy layer at different positions when the substrate was rotated at a different angle from the Cu-Au alloy layer described above, and it was found that the in-plane orientation of the two Cu-Au alloy layers was random. rice field.

Next, graphene was formed on the Cu—Au alloy layer by CVD. Using methane gas as a carbon raw material, graphene was formed at a film forming temperature of 900 ° C. When the formed graphene was confirmed, it had a regular hexagonal shape having the same size as the Cu—Au alloy layer in a plan view.

Next, graphene was peeled off from the Cu—Au alloy layer and graphene was transferred to another substrate. First, PMMA was spin-coated and baked, and a plastic substrate coated with PMMA was adhered as a support substrate. It was immersed in an acid solution and gradually peeled off from the edge of the plastic substrate while dissolving the sacrificial layer and the metal layer. The single domain graphene layer was brought into close contact with the silicon oxide / silicon substrate, and the plastic substrate and PMMA were dissolved and removed.

Au / Ti was vapor-deposited using a photolithography technique to form a source electrode and a drain electrode. The functionalized pyrene derivative solution was brought into contact with the graphene layer, and the graphene and the pyrene portion of the pyrene derivative were bonded by a π stack. As a result, a detection element using a FETC was manufactured.

When the carrier mobility of the produced graphene layer was measured, it was about 10,000 cm ² / Vs. In addition, the manufactured detection element was able to detect the C agent simulated gas diluted to the order of ppt, and functioned as a high-sensitivity gas sensor.

(Comparative Example 1)
Single-layer graphene is formed on a 4-inch SiO / Si wafer by CVD, the resist is patterned into 5 μm squares using photolithography technology, and multiple graphenes are formed by reactive ion etching (RIE). The layers were patterned. After removing the resist, Au / Ti was vapor-deposited using a photolithography technique to form a source electrode and a drain electrode. After lift-off of the resist, the functionalized pyrene derivative solution was brought into contact with the graphene layer, and the graphene and the pyrene portion of the pyrene derivative were bonded by a π stack. As a result, a detection element using a FETC was manufactured.

When the carrier mobility of the produced graphene layer was measured, it was about 700 cm ² / Vs. In addition, the manufactured detection element could not detect the C agent simulated gas diluted to the order of ppt.

(Comparative Example 2)
A resist was applied to the single-layer peeled graphene peeled and transferred by scotch tape on a 4-inch SiO / Si wafer, and Au / Ti was vapor-deposited using photolithography technology to form source and drain electrodes. After lift-off of the resist, the functionalized pyrene derivative solution was brought into contact with the graphene layer, and the graphene and the pyrene portion of the pyrene derivative were bonded by a π stack. As a result, a detection element using a FETC was manufactured.

When the carrier mobility of the produced graphene layer was measured, it was about 2000 cm ² / Vs. In addition, the manufactured detection element could not detect the C agent simulated gas diluted to the order of ppt.

Although some embodiments of the present invention have been described, these novel embodiments are presented as examples and are not intended to limit the scope of the invention. It can be carried out in various forms, and various omissions, replacements and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Molecule detector, 2 ... Target molecule, 3 ... Target gas, 4 ... Contaminants, 5 ... Filter device, 6 ... Molecular distributor, 6a ... End, 10 ... Detector, 10A ... Detection surface, 11 ... Sensor , 12 ... Organic probe, 13 ... Detection element, 17 ... Source electrode, 18 ... Drain electrode, 20 ... Discriminator, 30 ... Information processing unit, 31 ... Information transmission unit, 32 ... Information receiving unit, 33 ... Information collation unit, 100 ... Substrate, 101 ... Substrate, 101a ... Semiconductor substrate, 101b ... Insulation film, 102 ... Single domain graphene layer, 103 ... Substrate, 104 ... Cu—M alloy layer, 104a ... Crystal phase, 104b ... Crystal grain boundary, 105 ... resin layer, 106 ... support substrate, 111 ... detection cell.

Claims (9)

With the board
A plurality of single domain graphene layers juxtaposed on the substrate are provided.
The plurality of single-domain graphene layers have a 3n rotationally symmetric shape (n is a natural number) centered on the center point of the single-domain graphene layer in a plan view .
The plurality of single domain graphene layers have a crystalline phase having a six-membered ring structure of carbon atoms.
The crystal phases of the plurality of single domain graphene layers are electronic devices oriented in different directions from each other . With the board
A plurality of single domain graphene layers juxtaposed on the substrate are provided.
The plurality of single domain graphene layers have a regular hexagonal shape in a plan view and have a regular hexagonal shape.
The plurality of single domain graphene layers have a crystalline phase having a six-membered ring structure of carbon atoms.
The crystal phase of the plurality of single domain graphene layers is an electronic element oriented in different directions from each other . The electronic device according to claim 1 or 2 , wherein the plurality of single domain graphene layers are single layers. The electronic device according to any one of claims 1 to 3 , wherein the area of the plurality of single domain graphene layers in a plan view is 1 μm ² or more and 1000000 μm ² or less. The electronic device according to any one of claims 1 to 4 , wherein the shortest distance between adjacent single domain graphene layers is 10 μm or more and 10000 μm or less. The electronic device according to any one of claims 1 to 5 , wherein the carrier mobility of the plurality of single domain graphene layers is 10,000 cm ² / Vs or more. The electronic element according to any one of claims 1 to 6 is provided.
The electronic element has a plurality of detection cells and has a plurality of detection cells.
The plurality of detection cells are formed on one of the plurality of single domain graphene layers, a source electrode connected to the single domain graphene layer, a drain electrode connected to the single domain graphene layer, and the single domain graphene layer. A molecule detection device comprising a field effect transistor with a superposed gate electrode. The plurality of detection cells further include at least one organic probe provided on the single domain graphene layer, and the target molecule is detected by the interaction between the organic probe and the target molecule, according to claim 7 . The molecular detector according to description. The at least one organic probe
The molecule detection device according to claim 8 , further comprising a plurality of organic probes having different binding strengths with the target molecule.

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