Anisotropic device and its preparation method and application

Abstract

The present invention provides an anisotropic device, comprising a substrate layer, an isolation layer and a two-dimensional nano film layer sequentially stacked on the substrate layer, wherein the two-dimensional nano film layer covers part of the isolation layer, and further comprises a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes; the central source electrode / central drain electrode is arranged in the middle of the two-dimensional nano film layer, and a plurality of peripheral drain electrodes / peripheral source electrodes are arranged on the isolation layer along the circumference of the central source electrode / central drain electrode, and the plurality of peripheral drain electrodes / peripheral source electrodes extend toward the two-dimensional nano film layer until they contact the two-dimensional nano film layer. The anisotropic device can utilize the anisotropic characteristics of the two-dimensional nano film layer to realize the detection of the current magnitude in different directions on the material, fully utilize the anisotropy of the material, and has great potential applications in the fields of electronics and optoelectronics. The present invention also provides a preparation method and application of the anisotropic device.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor electronic devices, and in particular to an anisotropic device and a preparation method and application thereof. Background Art

[0002] Anisotropy refers to the fact that all or part of the chemical, physical and other properties of a substance change with the change of direction, showing different properties in different directions. From a microscopic point of view, the anisotropy of crystals is that in the same crystal, due to the different orientations of the crystal planes, the physical and chemical properties of the crystals in different directions are also different. The anisotropy of crystals is specifically manifested in the different elastic modulus, hardness, fracture resistance, yield strength, thermal expansion coefficient, thermal conductivity, resistivity, electric displacement vector, electric polarization, magnetic susceptibility and refractive index in different directions of the crystal. Anisotropy, as an important property of crystals, has considerable research value. In recent years, anisotropy has attracted more and more attention, especially in epitaxial thin film materials.

[0003] III-VI semiconductor materials have great potential applications in electronics and optoelectronics due to their special electrical and optical properties. However, traditional semiconductor electronic devices only utilize the performance of the corresponding material in one dimension, and do not take advantage of the anisotropy of the material. Summary of the invention

[0004] In view of this, the present invention provides an anisotropic device and a preparation method and application thereof. The anisotropic device can utilize the anisotropic properties of two-dimensional nano-thin film layer materials to realize the detection of current magnitudes in different directions on the material, making full use of the anisotropy of the material, and has great potential applications in the fields of electronics and optoelectronics.

[0005] In a first aspect, the present invention provides an anisotropic device, comprising a substrate layer, an isolation layer and a two-dimensional nanofilm layer sequentially stacked on the substrate layer, wherein the two-dimensional nanofilm layer covers a portion of the isolation layer, and further comprises a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes;

[0006] The central source electrode / central drain electrode is arranged in the middle of the two-dimensional nanofilm layer, the plurality of peripheral drain electrodes / peripheral source electrodes are arranged on the isolation layer along the circumference of the central source electrode / central drain electrode, and the plurality of peripheral drain electrodes / peripheral source electrodes extend toward the two-dimensional nanofilm layer until they contact the two-dimensional nanofilm layer;

[0007] The two-dimensional nanofilm layer is an anisotropic two-dimensional nanofilm layer.

[0008] In a specific embodiment of the present invention, the material of the two-dimensional nano-thin film layer is rhenium disulfide, or rhenium diselenide, or black phosphorus, or black arsenic phosphorus, or β-phase indium selenide.

[0009] In another specific embodiment of the present invention, the material of the two-dimensional nano-thin film layer includes two or more of rhenium disulfide, rhenium diselenide, black phosphorus, black arsenic phosphorus and β-phase indium selenide.

[0010] Preferably, the material of the two-dimensional nanofilm layer is β-phase indium selenide.

[0011] Optionally, the two-dimensional nanofilm layer is configured to be disc-shaped, the central source electrode / central drain electrode is disposed at the center of the two-dimensional nanofilm layer, and the plurality of peripheral drain electrodes / peripheral source electrodes are arranged in a circular array along the outer periphery of the two-dimensional nanofilm layer.

[0012] Optionally, the number of the plurality of surrounding drain electrodes / surrounding source electrodes is 4-36, and the angle between any two adjacent surrounding drain electrodes / surrounding source electrodes is 10-90°.

[0013] Optionally, a distance between the central source electrode / central drain electrode and the peripheral drain electrode / peripheral source electrode is 10 μm-50 μm.

[0014] Optionally, the anisotropic device comprises a plurality of spaced-apart two-dimensional nano-thin film layers stacked on the isolation layer, and a distance between any two adjacent two-dimensional nano-thin film layers is 10 μm-500 μm.

[0015] Optionally, the thickness of the two-dimensional nanofilm layer is 2nm-80nm.

[0016] Optionally, the thicknesses of the two-dimensional nanofilm layers may be the same or different.

[0017] Further, optionally, the materials of each of the two-dimensional nanofilm layers may be the same or different.

[0018] Optionally, the material of the source electrode (specifically the central source electrode or the peripheral source electrode) and the drain electrode (specifically the central drain electrode or the peripheral drain electrode) includes at least one of chromium and gold; the thickness of the source electrode and the drain electrode is 25nm-90nm.

[0019] Optionally, the resistivity of the base layer is 1-10Ω·cm, the thickness of the base layer is 300μm-500μm; and the thickness of the isolation layer is 200nm-500nm.

[0020] Optionally, the material of the base layer includes silicon, and the material of the isolation layer includes silicon dioxide.

[0021] In the present invention, based on the anisotropic two-dimensional nanofilm layer, a back-gate semiconductor can be formed. Based on the anisotropy of the two-dimensional nanofilm layer itself in terms of conductivity, the current distribution characteristics of the two-dimensional nanofilm layer material in different directions, etc., based on the anisotropic material, the different current sizes in different directions can be used to perform corresponding information editing and storage; the anisotropic device can provide important detection data for realizing the storage of information in the integrated circuit, greatly exerting the anisotropic function of the material itself. The two-dimensional nanofilm layer prepared from ReS2, ReSe2, BP, b-AsP or β-InSe materials has outstanding anisotropic properties, especially the two-dimensional β-InSe nanofilm layer has both good semiconductor properties and special anisotropic properties.

[0022] The anisotropic device described in the first aspect of the present invention can effectively detect the photoelectric properties of the two-dimensional nanofilm layer in different directions, and can fully utilize the anisotropic effects of the two-dimensional nanofilm layer material; it is of great significance in the application field of anisotropic materials.

[0023] In a second aspect, the present invention further provides a method for preparing an anisotropic device, comprising the following steps:

[0024] Providing a base layer and an isolation layer;

[0025] A two-dimensional nanofilm layer is obtained by a peeling method, and then the two-dimensional nanofilm layer is transferred to the isolation layer, wherein the material of the two-dimensional nanofilm layer is an anisotropic two-dimensional nanofilm layer;

[0026] Depositing electrode materials to form a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes to obtain an anisotropic device;

[0027] The central source electrode / central drain electrode is arranged in the middle of the two-dimensional nanofilm layer, the plurality of surrounding drain electrodes / peripheral source electrodes are arranged on the isolation layer along the circumference of the central source electrode / central drain electrode, and the plurality of surrounding drain electrodes / peripheral source electrodes extend toward the two-dimensional nanofilm layer until they contact the two-dimensional nanofilm layer.

[0028] Optionally, during the deposition of the electrode material, photoresist is spin-coated on the two-dimensional nanofilm layer and on the isolation layer not covered by the two-dimensional nanofilm layer, and after exposure and development, an electrode pattern is formed;

[0029] After the electrode material is deposited, the photoresist is then removed to form a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes.

[0030] Optionally, the process of obtaining a two-dimensional nanofilm layer by the peeling method includes: taking a small amount of single crystal raw material and sticking it to a tape, repeatedly tearing it 10-40 times, and then transferring the torn two-dimensional nanofilm sample to an isolation layer to form a two-dimensional nanofilm layer.

[0031] Optionally, the process of transferring the two-dimensional nanofilm sample to the isolation layer includes: transferring the two-dimensional nanofilm sample to a polydimethylsiloxane film, and then transferring the two-dimensional nanofilm sample on the polydimethylsiloxane film to the isolation layer.

[0032] The preparation method described in the second aspect of the present invention has simple steps, low cost, and can be used for large-scale industrial production; the anisotropic device prepared can effectively detect the photoelectric properties of the two-dimensional nanofilm layer in different directions, fully explore the anisotropy of the material, and has huge potential applications in the fields of electronics and optoelectronics.

[0033] In a third aspect, the present invention further provides an application of the anisotropic device as described in the first aspect of the present invention in the field of information storage.

[0034] The anisotropic device of the present invention can fully measure the specific anisotropic characteristics of materials, for example, the current distribution characteristics of two-dimensional nano-thin film materials in different directions, etc. The anisotropic device has high potential application value in the fields of optics, electrical conduction, thermal conduction or magnetic field. In particular, based on the anisotropic material, the different current sizes in different directions can be used to edit and store corresponding information; the anisotropic device can provide important detection data for realizing the storage of information in integrated circuits, greatly exerting the anisotropic function of the material itself.

[0035] Advantages of the present invention will be partially set forth in the following description, and partly will be obvious from the description, or may be learned through implementation of the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the content of the present invention, it is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Figure 1 A schematic structural diagram of an anisotropic device provided in one embodiment of the present invention;

[0038] Figure 2 A schematic structural diagram of an anisotropic device provided in another embodiment of the present invention;

[0039] Figure 3 A schematic diagram of the structure of the preparation process of an anisotropic device provided in one embodiment of the present invention;

[0040] Figure 4This is an electrical test diagram of the anisotropic device prepared in Example 1. DETAILED DESCRIPTION

[0041] The following is a preferred embodiment of the present invention. It should be noted that a person skilled in the art may make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

[0042] Please refer to Figure 1 , Figure 1 An anisotropic device 100 provided in one embodiment of the present invention comprises a substrate layer 10, an isolation layer 20 and a two-dimensional nano film layer 30 sequentially stacked on the substrate layer 10, wherein the two-dimensional nano film layer 30 covers part of the isolation layer 20, that is, the two-dimensional nano film layer 30 only covers part of the isolation layer 20, and there is a part on the surface of the isolation layer 20 that is not covered by the two-dimensional nano film layer 30 and is directly exposed. The anisotropic device 100 also includes a central source electrode 41 and twelve surrounding drain electrodes 42, wherein the central source electrode 41 is arranged in the middle (middle position) of the two-dimensional nano film layer 30, that is, the central source electrode 41 is completely arranged on the two-dimensional nano film layer 30, and the central source electrode 41 does not contact the isolation layer 20 and the surrounding drain electrodes 42; the twelve surrounding drain electrodes 42 are arranged on the isolation layer 20 along the circumference of the central source electrode 41 (arranged around the central source electrode 41), and the twelve surrounding drain electrodes 42 extend toward the two-dimensional nano film layer 30 to contact the two-dimensional nano film layer 30. The two-dimensional nanofilm layer 30 is an anisotropic two-dimensional nanofilm layer. Thus, the central source electrode 41 can be connected to the twelve surrounding drain electrodes 42 through the two-dimensional nanofilm layer 30. With the help of the anisotropic characteristics of the two-dimensional nanofilm layer 30, the central source electrode 41 and different surrounding drain electrodes 42 have different conductivities. This characteristic can be used to prepare anisotropic devices and applied to the field of detectors. Based on the anisotropic material, the different currents in different directions can also be used to edit and store corresponding information; the anisotropic device can provide important detection data for the storage of information in the integrated circuit, greatly giving play to the anisotropic function of the material itself.

[0043] The anisotropic device provided in another embodiment of the present invention has a similar structure to the anisotropic device 100, the only difference being that the central source electrode 41 is configured as a central drain electrode, and the twelve peripheral drain electrodes 42 are configured as twelve peripheral source electrodes, and the working principle is the same, and the anisotropy is the same. Hereinafter, the specific structure and parameters of the anisotropic device are described in detail by taking the anisotropic device 100 as an example, and the specific structure and parameters of the central source electrode 41 of the anisotropic device 100 of this embodiment are also applicable to the central drain electrode of the anisotropic device of another embodiment, and the specific structure and parameters of the peripheral drain electrode 42 of the anisotropic device 100 of this embodiment are also applicable to the peripheral source electrode of the anisotropic device of another embodiment.

[0044] In an embodiment of the present invention, the two-dimensional nanofilm layer 30 may be, but not limited to, a two-dimensional β-InSe nanofilm layer, or a two-dimensional ReS2 nanofilm layer, or a two-dimensional ReSe2 nanofilm layer, or a two-dimensional BP nanofilm layer, or a two-dimensional b-AsP nanofilm layer. Alternatively, the two-dimensional nanofilm layer 30 may be, but not limited to, a mixed film layer composed of a two-dimensional β-InSe nanofilm, a two-dimensional ReS2 nanofilm, a two-dimensional ReSe2 nanofilm, a two-dimensional BP nanofilm, and a two-dimensional b-AsP nanofilm, which can also ensure that the prepared two-dimensional nanofilm layer 30 has anisotropic properties. More preferably, the two-dimensional nanofilm layer 30 is a two-dimensional β-InSe nanofilm layer. Wherein, the thickness of the above-mentioned two-dimensional nanofilm layer 30 is 2nm-80nm.

[0045] Furthermore, the thickness of the two-dimensional nanofilm layer 30 is 10 nm-50 nm.

[0046] Furthermore, the thickness of the two-dimensional nanofilm layer 30 is 50nm-80nm.

[0047] For example, in one embodiment of the present invention, the thickness of the two-dimensional nanofilm layer 30 is 2 nm, or 5 nm, or 10 nm, or 20 nm, or 30 nm, or 35 nm, or 45 nm, or 50 nm, or 60 nm, or 70 nm, or 80 nm.

[0048] Furthermore, the two-dimensional nanofilm layer 30 is arranged in a disk shape, the central source electrode 41 is arranged at the center of the two-dimensional nanofilm layer 30, and the surrounding drain electrodes 42 are arranged in a circular array along the outer periphery of the two-dimensional nanofilm layer 30, that is, Figure 1As shown, the peripheral drain electrodes 42 are radially distributed on the outer periphery of the two-dimensional nano film layer 30 in a centrally symmetrical manner, and the peripheral drain electrodes 42 extend from the two-dimensional nano film layer 30 to the isolation layer 20, and the distances between any two adjacent peripheral drain electrodes 42 are equal. Thus, it is ensured that the distances from each peripheral drain electrode 42 to the central source electrode 41 are equal, and only the orientations of the two-dimensional nano film layer 30 are different, that is, the conductivity characteristics between the peripheral drain electrodes 42 and the central source electrode 41 are characterized by the anisotropy of the two-dimensional nano film layer 30 itself. In other embodiments, the distances from each peripheral drain electrode 42 to the central source electrode 41 may be unequal, and the two-dimensional nano film layer may also be set to an ellipse, polygon, star, or irregular shape, and only the conductivity characteristics between the peripheral drain electrodes 42 and the central source electrode 41 are ensured to be different in each direction, which can also be applied to the detector field and the information editing and storage field.

[0049] Optionally, the length and width of the two-dimensional nano film layer 30 are 15 μm-80 μm.

[0050] Further optionally, the length and width of the two-dimensional nano film layer 30 are 20 μm-50 μm.

[0051] For example, in one embodiment of the present invention, the length and width of the two-dimensional nanofilm layer are 15 μm, or 20 μm, or 30 μm, or 40 μm, or 50 μm, or 60 μm, or 70 μm, or 80 μm.

[0052] In an embodiment of the present invention, the material of the base layer 10 includes silicon. Further, optionally, the base layer 10 is p-type or n-type doped silicon.

[0053] Optionally, the base layer 10 has a thickness of 300 μm-500 μm.

[0054] Further, optionally, the base layer 10 has a thickness of 400 μm-500 μm.

[0055] The resistivity of the base layer 10 is 1-10Ω·cm.

[0056] In an embodiment of the present invention, the material of the isolation layer 20 includes silicon dioxide. Optionally, the thickness of the isolation layer 20 is 200nm-500nm.

[0057] Further, optionally, the isolation layer 20 has a thickness of 300nm-500nm.

[0058] For example, in one embodiment of the present invention, the thickness of the isolation layer 20 is 200 nm, or 250 nm, or 300 nm, or 350 nm, or 400 nm, or 450 nm, or 500 nm.

[0059] Optionally, the number of surrounding drain electrodes 42 is 4-36, and the angle between any two adjacent surrounding drain electrodes 42 is 10-90°. For example, in this embodiment, the number of surrounding drain electrodes 42 is 12, and the angle between any two adjacent surrounding drain electrodes 42 is 30°.

[0060] Optionally, the material of the central source electrode 41 and the peripheral drain electrode 42 includes at least one of chromium and gold; the thickness of the central source electrode 41 and the peripheral drain electrode 42 is 25 nm-90 nm.

[0061] Optionally, the thickness of the central source electrode 41 and the peripheral drain electrode 42 is 25 nm-50 nm.

[0062] Optionally, the thickness of the central source electrode 41 and the peripheral drain electrode 42 is 50 nm-90 nm.

[0063] For example, in one embodiment of the present invention, the thickness of the central source electrode 41 and the surrounding drain electrode 42 is 25 nm, or 30 nm, or 35 nm, or 40 nm, or 50 nm, or 60 nm, or 70 nm, or 80 nm, or 90 nm.

[0064] In the embodiment of the present invention, the material of the central source electrode 41 and the peripheral drain electrode 42 includes at least one of gold and chromium. In this embodiment, the material of the central source electrode 41 and the material of the peripheral drain electrode 42 can be the same or different.

[0065] Optionally, the cross-sectional shape of the peripheral drain electrode 42 may be, but is not limited to, rectangular, circular, triangular or polygonal.

[0066] For example, in this embodiment, the cross-sectional shape of the peripheral drain electrode 42 is a rectangle.

[0067] In this embodiment, in order to ensure that the distances from the central source electrode 41 to each peripheral drain electrode 42 are equal and to ensure that the conductivity characteristics between the central source electrode 41 and the peripheral drain electrodes 42 are only affected by the direction angle, a disc-shaped central source electrode 41 is used and the central source electrode 41 is arranged at the center of the two-dimensional nanofilm layer 30. Preferably, as Figure 1As shown, the central source electrode 41 may further extend electrode feet radially toward each peripheral drain electrode 42, so as to highlight the conductivity characteristics of the anisotropic device 100. In other embodiments, the central source electrode 41 may also be configured as a regular dodecagon, and any corner of the regular dodecagon central source electrode 41 faces one of the peripheral drain electrodes 42, which can also ensure that the distances from the central source electrode 41 to each peripheral drain electrode 42 are equal.

[0068] In other embodiments, the distances from each peripheral drain electrode 42 to the central source electrode 41 may not be equal, and the central source electrode 41 may be set to an ellipse, polygon, star, or irregular shape, as long as the conductivity characteristics between the peripheral drain electrodes 42 and the central source electrode 41 are different as the direction angle changes.

[0069] For example, in one embodiment of the present invention, the central source electrode 41 and the surrounding drain electrode 42 are composed of a chromium layer and a gold layer sequentially stacked on the two-dimensional nano-film layer 30, wherein the thickness of the chromium layer is 5nm-10nm, and the thickness of the gold layer is 20nm-80nm. The central source electrode 41 and the surrounding drain electrode 42 composed of the chromium layer and the gold layer have better electrochemical properties and can maintain good contact with the two-dimensional nano-film layer 30.

[0070] In one embodiment of the present invention, the central source electrode 41 and the peripheral drain electrode 42 may include both a chromium layer and a gold layer; and a portion of the peripheral drain electrode 42 contacts the two-dimensional nanofilm layer 30 , and another portion contacts the isolation layer 20 .

[0071] In this implementation, the anisotropic device includes N peripheral drain electrodes 42 , where N is a positive integer greater than or equal to 4. Furthermore, the number N may be less than 20.

[0072] Optionally, the included angle between any two adjacent peripheral drain electrodes 42 may also be other angles a.

[0073] Optionally, the distance between the central source electrode 41 and the peripheral drain electrode 42 is 10 μm-50 μm. In this embodiment, the distance between the central source electrode 41 and the peripheral drain electrode 42 is the distance between the proximal end of the peripheral drain electrode 42 and the center of the disk-shaped central source electrode 41 .

[0074] In an embodiment of the present invention, the material of the two-dimensional nano film layer 30 is selected from one or more of ReS2, ReSe2, BP, b-AsP and β-InSe. The two-dimensional nano film layer 30 has both good semiconductor properties and special anisotropic properties; but since anisotropy is in the same crystal, the orientation of the crystal plane is different, resulting in different physical and chemical properties of the crystal in different directions. The anisotropic device of the present invention utilizes the anisotropic properties of the two-dimensional nano film layer material and can have huge potential applications in the fields of electronics and optoelectronics.

[0075] A second aspect of the present invention provides a method for preparing an anisotropic device, such as Figure 3 As shown, the following steps are included:

[0076] S01, providing a base layer, and disposing an isolation layer on the base layer, or providing a base layer provided with an isolation layer;

[0077] S02, obtaining a two-dimensional nanofilm layer by a peeling method, and then transferring the two-dimensional nanofilm layer to the isolation layer;

[0078] S03, spin-coating photoresist on the two-dimensional nanofilm layer and on the isolation layer not covered by the two-dimensional nanofilm layer, and forming an electrode pattern after exposure and development;

[0079] S04, depositing electrode materials, then removing the photoresist, forming peripheral drain electrodes and central source electrodes laid on the two-dimensional nanofilm layer and distributed radially, the central source electrode is arranged in the middle of the two-dimensional nanofilm layer, the peripheral drain electrodes are arranged on the isolation layer along the circumference of the central source electrode, and the peripheral drain electrodes extend toward the two-dimensional nanofilm layer until they contact the two-dimensional nanofilm layer. Then, after cleaning, an anisotropic device is obtained.

[0080] In the embodiment of the present invention, in step S01, the base layer and the isolation layer can be cut into 1×1 cm by using a silicon wafer cutter to cut a commercial standard 4-inch p-type or n-type doped single-throw silicon oxide wafer (including a silicon portion with a thickness of 300 μm-500 μm and a resistivity of 1-10 Ω·cm, and a silicon dioxide portion with a thickness of 300 nm) into 1×1 cm 2 The base layer and the isolation layer can also be formed by stacking a silicon dioxide isolation layer on a p-type or n-type doped silicon layer.

[0081] Optionally, after the isolation layer is provided and before the two-dimensional nanofilm layer is transferred, the substrate layer and the isolation layer are pretreated; the pretreatment process includes: placing the obtained substrate layer containing the isolation layer in an acetone solution and an alcohol solution for ultrasonic treatment for 5-15 minutes respectively, then transferring it to deionized water for ultrasonic treatment for 5-15 minutes, and then quickly drying it with high-purity nitrogen for standby use. The alcohol solution includes at least one of an ethanol solution or an isopropanol solution.

[0082] In the embodiment of the present invention, in step S02, the process of obtaining the two-dimensional nanofilm layer by the peeling method includes: taking a small amount of single crystal raw material (such as β-InSe single crystal), sticking it to a tape (such as Scotch tape), repeatedly tearing it 10-40 times, and then transferring the torn two-dimensional nanofilm sample to a polydimethylsiloxane (PDMS) film 50 (such as Figure 3 As shown), the two-dimensional nanofilm sample on the polydimethylsiloxane film 50 is then transferred to the isolation layer.

[0083] In the embodiment of the present invention, multiple two-dimensional nanofilm samples can be obtained by repeatedly tearing 10-40 times, and at least one two-dimensional nanofilm sample can be transferred to the isolation layer through the PDMS film. For example, multiple two-dimensional nanofilm samples can be distributed on the isolation layer at intervals to obtain multiple two-dimensional nanofilm layers arranged at intervals on the isolation layer.

[0084] In an embodiment of the present invention, in step S04, a layer of photoresist (PMMA) is spin-coated on the two-dimensional nanofilm layer and on the isolation layer not covered by the two-dimensional nanofilm layer; then baked on a hot plate for 1-5 minutes, the drying temperature is 50-180°C, wherein the spin coating speed is 2000-4000 rpm. The sample coated with the photoresist is subjected to electron beam exposure, and a specific electrode pattern is obtained through a development process. In the embodiment of the present invention, the electrode pattern includes multiple pairs of through holes that penetrate the photoresist and expose part of the two-dimensional nanofilm layer.

[0085] In the embodiment of the present invention, by pre-designing the electrode pattern, various types of central source electrodes and peripheral drain electrodes can be obtained accordingly. Figure 1 The plurality of surrounding drain electrodes are radially distributed on the two-dimensional nanofilm layer, and the angles between two adjacent surrounding drain electrodes are different.

[0086] Optionally, a plurality of spaced-apart two-dimensional nanofilm layers 30 may be stacked on the isolation layer. The distance L between any two adjacent two-dimensional nanofilm layers is 10 μm-500 μm, see Figure 2 .

[0087] Optionally, the cross-sectional shape of the through hole may be, but is not limited to, rectangular, circular, triangular or polygonal.

[0088] Optionally, the model of the photoresist may be but is not limited to 950 (A4-A10).

[0089] In the embodiment of the present invention, in step S04, electrode material is deposited above the through hole, and the electrode material fills the through hole and contacts the light absorbing layer to form a plurality of peripheral drain electrodes and a central source electrode.

[0090] Optionally, the deposition is performed by thermal evaporation or magnetron sputtering. For example, in one embodiment of the present invention, the source electrode and the drain electrode are formed by first depositing a chromium layer with a thickness of 5-10 nm and then depositing a gold layer with a thickness of 20-80 nm.

[0091] Optionally, after depositing the electrode material, the process also includes soaking the sample after depositing the electrode material in an acetone organic solvent to remove the photoresist, and heating it on a heating plate for 10-30 minutes, wherein the temperature of the heating plate is set to 30-50°C, and finally taking out the sample and quickly blowing it dry with high-purity nitrogen for cleaning.

[0092] Optionally, after the anisotropic device is prepared, a semiconductor characteristics analyzer may be used to perform relevant performance tests on the anisotropic device.

[0093] In this embodiment, the schematic diagram of the preparation process of the anisotropic device can be found in Figure 3 shown.

[0094] The preparation method described in the second aspect of the present invention has simple steps, low cost, and can be used for large-scale industrial production; the anisotropic device prepared can effectively detect the anisotropic photoelectric properties of the two-dimensional nanofilm layer in different directions, and is of great significance in the preparation of anisotropic photoelectric devices, anisotropic detectors and information storage applications.

[0095] Example 1

[0096] A method for preparing an anisotropic device based on a two-dimensional β-InSe nanofilm comprises the following steps:

[0097] (1) Clean the silicon wafer; cut a commercial standard 4-inch p-type or n-type doped single-throw silicon oxide wafer (thickness of the silicon portion is 300 μm-500 μm, resistivity is 1-10 Ω·cm, and thickness of silicon dioxide is 300 nm) into 1×1 cm 2 The size was ultrasonically applied to an acetone solution and isopropanol for 5 minutes respectively, and then ultrasonically applied to deionized water for 5 minutes and then quickly blown dry with high-purity nitrogen gas for standby use to obtain a silicon substrate layer and a silicon dioxide isolation layer stacked together.

[0098] (2) Sample preparation: Take a small amount of β-InSe single crystal and stick it to Scotch tape, tear it repeatedly 10-20 times, then transfer the torn β-InSe nanofilm sample to the polydimethylsiloxane film, and then transfer the β-InSe nanofilm sample on the polydimethylsiloxane film to the silicon dioxide isolation layer in step (1).

[0099] (3) Spin coating and drying; a layer of PMMA (A4) photoresist was spin coated on the surface of the silicon wafer at a speed of 3000 rpm, and baked on a heating plate for 5 minutes at a drying temperature of 120 degrees Celsius.

[0100] (4) Electron beam exposure and development: The sample coated with the photoresist is subjected to electron beam exposure, and a specific electrode pattern is obtained through a development process.

[0101] (5) Coating; 10 nm of chromium and 80 nm of gold are successively deposited by thermal evaporation to obtain a chromium / gold central source electrode and a peripheral drain electrode, and the peripheral drain electrodes are arranged in a circular array about the center of the two-dimensional nanofilm layer.

[0102] (6) Removing gold; soaking the sample with the evaporated chromium / gold central source electrode and the surrounding drain electrode in acetone and heating it on a heating plate for 10-30 minutes, wherein the temperature of the heating plate is set in the range of 30-50 degrees Celsius. Finally, taking out the sample and quickly blowing it dry with high-purity nitrogen to obtain an anisotropic device based on the two-dimensional β-InSe nanofilm.

[0103] Example 2

[0104] A method for preparing an anisotropic device based on a two-dimensional ReSe2 nanofilm comprises the following steps:

[0105] (1) Clean the silicon wafer; cut a commercial standard 4-inch p-type or n-type doped single-throw silicon oxide wafer (thickness of the silicon portion is 300 μm-500 μm, resistivity is 1-10 Ω·cm, and thickness of silicon dioxide is 300 nm) into 1×1 cm 2 The size was ultrasonically applied to an acetone solution and isopropanol for 5 minutes respectively, and then ultrasonically applied to deionized water for 5 minutes and then quickly blown dry with high-purity nitrogen gas for standby use to obtain a silicon substrate layer and a silicon dioxide isolation layer stacked together.

[0106] (2) Prepare samples; take a small amount of ReSe2 single crystal and stick it to Scotch tape, tear it repeatedly 10-20 times, then transfer the torn sample to a polydimethylsiloxane film, and then transfer the sample on the polydimethylsiloxane film to the silicon dioxide isolation layer in step (1).

[0107] (3) Spin coating and drying; a layer of PMMA (A4) photoresist was spin coated on the surface of the silicon wafer at a speed of 3000 rpm, and baked on a heating plate for 5 minutes at a drying temperature of 120 degrees Celsius.

[0108] (4) Electron beam exposure and development: The sample coated with the photoresist is subjected to electron beam exposure, and a specific electrode pattern is obtained through a development process.

[0109] (5) Coating; 10 nm of chromium and 80 nm of gold are successively deposited by thermal evaporation to obtain a chromium / gold central source electrode and a peripheral drain electrode, and the peripheral drain electrodes are arranged in a circular array about the center of the two-dimensional nanofilm layer.

[0110] (6) Removing gold; soaking the sample with the evaporated chromium / gold central source electrode and the surrounding drain electrode in acetone, and heating it on a heating plate for 10-30 minutes, wherein the temperature of the heating plate is set in the range of 30-50 degrees Celsius. Finally, taking out the sample and quickly blowing it dry with high-purity nitrogen to obtain an anisotropic device based on the two-dimensional ReSe2 nanofilm.

[0111] Example 3

[0112] A method for preparing an anisotropic device based on a two-dimensional ReS2 nanofilm comprises the following steps:

[0113] (1) Clean the silicon wafer; cut a commercial standard 4-inch p-type or n-type doped single-throw silicon oxide wafer (thickness of the silicon portion is 300 μm-500 μm, resistivity is 1-10 Ω·cm, and thickness of silicon dioxide is 300 nm) into 1×1 cm 2 The size was ultrasonically applied to an acetone solution and isopropanol for 5 minutes respectively, and then ultrasonically applied to deionized water for 5 minutes and then quickly blown dry with high-purity nitrogen gas for standby use to obtain a silicon substrate layer and a silicon dioxide isolation layer stacked together.

[0114] (2) Prepare samples; take a small amount of ReS2 single crystal and stick it to Scotch tape, tear it repeatedly 10-20 times, then transfer the torn sample to a polydimethylsiloxane film, and then transfer the sample on the polydimethylsiloxane film to the silicon dioxide isolation layer in step (1).

[0115] (3) Spin coating and drying; a layer of PMMA (A4) photoresist was spin coated on the surface of the silicon wafer at a speed of 3000 rpm, and baked on a heating plate for 5 minutes at a drying temperature of 120 degrees Celsius.

[0116] (4) Electron beam exposure and development: The sample coated with the photoresist is subjected to electron beam exposure, and a specific electrode pattern is obtained through a development process.

[0117] (5) Coating; 10 nm of chromium and 80 nm of gold are successively deposited by thermal evaporation to obtain a chromium / gold central source electrode and a peripheral drain electrode, and the peripheral drain electrodes are arranged in a circular array about the center of the two-dimensional nanofilm layer.

[0118] (6) Removing gold; soaking the sample with the evaporated chromium / gold central source electrode and the surrounding drain electrode in acetone, and heating it on a heating plate for 10-30 minutes, wherein the temperature of the heating plate is set in the range of 30-50 degrees Celsius. Finally, taking out the sample and quickly blowing it dry with high-purity nitrogen to obtain an anisotropic device based on the two-dimensional ReS2 nanofilm.

[0119] Example 4

[0120] A method for preparing an anisotropic device based on a two-dimensional b-AsP nanofilm comprises the following steps:

[0121] (1) Clean the silicon wafer; cut a commercial standard 4-inch p-type or n-type doped single-throw silicon oxide wafer (thickness of the silicon portion is 300 μm-500 μm, resistivity is 1-10 Ω·cm, and thickness of silicon dioxide is 300 nm) into 1×1 cm 2 The size was ultrasonically applied to an acetone solution and isopropanol for 5 minutes respectively, and then ultrasonically applied to deionized water for 5 minutes and then quickly blown dry with high-purity nitrogen gas for standby use to obtain a silicon substrate layer and a silicon dioxide isolation layer stacked together.

[0122] (2) Prepare a sample; take a small amount of b-AsP material and stick it to Scotch tape, tear it repeatedly 10-20 times, and then transfer the torn sample to a polydimethylsiloxane film, and then transfer the b-AsP nanofilm sample on the polydimethylsiloxane film to the silicon dioxide isolation layer in step (1).

[0123] (3) Spin coating and drying; a layer of PMMA (A4) photoresist was spin coated on the surface of the silicon wafer at a speed of 3000 rpm, and baked on a heating plate for 5 minutes at a drying temperature of 120 degrees Celsius.

[0124] (4) Electron beam exposure and development: The sample coated with the photoresist is subjected to electron beam exposure, and a specific electrode pattern is obtained through a development process.

[0125] (5) Coating; 10 nm of chromium and 80 nm of gold are successively deposited by thermal evaporation to obtain a chromium / gold central source electrode and a peripheral drain electrode, and the peripheral drain electrodes are arranged in a circular array about the center of the two-dimensional nanofilm layer.

[0126] (6) Removing gold; soaking the sample with the evaporated chromium / gold central source electrode and the surrounding drain electrode in acetone, and heating it on a heating plate for 10-30 minutes, wherein the temperature of the heating plate is set in the range of 30-50 degrees Celsius, and finally taking out the sample and quickly blowing it dry with high-purity nitrogen to obtain an anisotropic device based on the two-dimensional b-AsP nanofilm.

[0127] Example 5

[0128] A method for preparing an anisotropic device based on a two-dimensional BP nanofilm comprises the following steps:

[0129] (1) Clean the silicon wafer; cut a commercial standard 4-inch p-type or n-type doped single-throw silicon oxide wafer (thickness of the silicon portion is 300 μm-500 μm, resistivity is 1-10 Ω·cm, and thickness of silicon dioxide is 300 nm) into 1×1 cm 2 The size was ultrasonically applied to an acetone solution and isopropanol for 5 minutes respectively, and then ultrasonically applied to deionized water for 5 minutes and then quickly blown dry with high-purity nitrogen gas for standby use to obtain a silicon substrate layer and a silicon dioxide isolation layer stacked together.

[0130] (2) Prepare samples; take a small amount of BP material and stick it on Scotch tape, tear it repeatedly 10-20 times, and then transfer the torn sample to a polydimethylsiloxane film, and then transfer the BP nanofilm sample on the polydimethylsiloxane film to the silicon dioxide isolation layer in step (1).

[0131] (3) Spin coating and drying; a layer of PMMA (A4) photoresist was spin coated on the surface of the silicon wafer at a speed of 3000 rpm, and baked on a heating plate for 5 minutes at a drying temperature of 120 degrees Celsius.

[0132] (4) Electron beam exposure and development: The sample coated with the photoresist is subjected to electron beam exposure, and a specific electrode pattern is obtained through a development process.

[0133] (5) Coating; 10 nm of chromium and 80 nm of gold are successively deposited by thermal evaporation to obtain a chromium / gold central source electrode and a peripheral drain electrode, and the peripheral drain electrodes are arranged in a circular array about the center of the two-dimensional nanofilm layer.

[0134] (6) Removing gold; soaking the sample with the evaporated chromium / gold central source electrode and the surrounding drain electrode in acetone, and heating it on a heating plate for 10-30 minutes, wherein the temperature of the heating plate is set in the range of 30-50 degrees Celsius, and finally taking out the sample and quickly blowing it dry with high-purity nitrogen to obtain an anisotropic device based on the two-dimensional BP nanofilm.

[0135] Effect embodiment:

[0136] A testing method for detecting transport anisotropy of two-dimensional β-InSe, the method comprising the following steps:

[0137] (1) Take the anisotropic device prepared in Example 1 and cut the silicon dioxide isolation layer at one corner of the silicon wafer using a silicon wafer knife.

[0138] (2) Place it on the probe platform of the semiconductor characteristics analyzer and use the matching CCD imaging system to find the exact position of the device on the silicon wafer.

[0139] (3) First, evacuate the chamber where the probe platform is placed with the sample. When the vacuum reaches 5×10 -2 When measuring Torr, two probes matching the probe station are selected, one probe contacts the central source electrode of the device, and the other probe contacts different surrounding drain electrodes. Another probe is selected to contact the silicon dioxide isolation layer cut in step (1) as a back gate electrode with anisotropic properties.

[0140] (4) Open the semiconductor characteristics analyzer test software, select the voltage scan mode for the drain probe, set the scan range to -1V-1V, set the gate voltage to 0V, and the source voltage to 0V.

[0141] (5) Run the test software to obtain the electrical test diagram of the device.

[0142] (6) Adjust the probe to measure the device in the directions of 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, 330°, and 360°, and obtain the electrical test diagram of the device respectively. Figure 4 .

[0143] from Figure 4 It can be seen that different source-drain voltages (V ds ) is the relationship between the current magnitude and the measurement direction. Each curve is obtained by measuring the current value at 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, and 360 degrees, and then fitting the result through the function. Figure 4 The content can specifically reflect the difference in the magnitude of the current of the material in different directions, thus reflecting the function of the anisotropic device. By obtaining the difference in the magnitude of the current in different directions based on the two-dimensional β-InSe nanofilm layer, it can be designed or made into an integrated circuit with information storage function, which will have great practical value.

[0144] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An anisotropic device, characterized in that: It includes a base layer, an isolation layer and a two-dimensional nano film layer sequentially stacked on the base layer, wherein the two-dimensional nano film layer covers part of the isolation layer, and further includes a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes; The central source electrode / central drain electrode is arranged in the middle of the two-dimensional nanofilm layer, the plurality of peripheral drain electrodes / peripheral source electrodes are arranged on the isolation layer along the circumference of the central source electrode / central drain electrode, and the plurality of peripheral drain electrodes / peripheral source electrodes extend toward the two-dimensional nanofilm layer until they contact the two-dimensional nanofilm layer; The two-dimensional nanofilm layer is an anisotropic two-dimensional nanofilm layer; The material of the two-dimensional nanofilm layer includes at least one of rhenium disulfide, rhenium diselenide, black phosphorus, black arsenic phosphorus and β-phase indium selenide; The material of the two-dimensional nanofilm layer is β-phase indium selenide; The two-dimensional nanofilm layer is arranged in a disk shape, the central source electrode / central drain electrode is arranged at the center of the two-dimensional nanofilm layer, and the plurality of peripheral drain electrodes / peripheral source electrodes are arranged in a circular array along the outer periphery of the two-dimensional nanofilm layer; The number of the plurality of surrounding drain electrodes / surrounding source electrodes is 4-36, and the angle between any two adjacent surrounding drain electrodes / surrounding source electrodes is 10-90°; The anisotropic device comprises a plurality of spaced two-dimensional nano-thin film layers stacked on the isolation layer, and the distance between any two adjacent two-dimensional nano-thin film layers is 10 μm-500 μm; The thickness of the two-dimensional nanofilm layer is 2nm-80nm.

2. A method for preparing an anisotropic device, characterized in that: The following steps are involved: Providing a base layer and an isolation layer; A two-dimensional nanofilm layer is obtained by a peeling method, and then the two-dimensional nanofilm layer is transferred to the isolation layer, wherein the material of the two-dimensional nanofilm layer is an anisotropic two-dimensional nanofilm layer; Depositing electrode materials to form a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes to obtain an anisotropic device; The central source electrode / central drain electrode is arranged in the middle of the two-dimensional nanofilm layer, the plurality of peripheral drain electrodes / peripheral source electrodes are arranged on the isolation layer along the circumference of the central source electrode / central drain electrode, and the plurality of peripheral drain electrodes / peripheral source electrodes extend toward the two-dimensional nanofilm layer until they contact the two-dimensional nanofilm layer; During the deposition of the electrode material, a photoresist is spin-coated on the two-dimensional nanofilm layer and on the isolation layer not covered by the two-dimensional nanofilm layer, and an electrode pattern is formed after exposure and development; After depositing the electrode material, the photoresist is then removed to form a central source electrode / central drain electrode and a plurality of peripheral drain electrodes / peripheral source electrodes; The process of obtaining a two-dimensional nanofilm layer by the peeling method includes: taking a small amount of single crystal raw material and sticking it to a tape, repeatedly tearing it 10-40 times, and then transferring the torn two-dimensional nanofilm sample to an isolation layer to form a two-dimensional nanofilm layer; The process of transferring the two-dimensional nanofilm sample to the isolation layer includes: transferring the two-dimensional nanofilm sample to the polydimethylsiloxane film, and then transferring the two-dimensional nanofilm sample on the polydimethylsiloxane film to the isolation layer.

3. Application of an anisotropic device in the field of information storage, applied to an anisotropic device as claimed in claim 1.

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