N-type carbon-based field effect transistor and preparation method thereof

Abstract

The invention relates to the technical field of semiconductor devices, in particular to an N-type carbon-based field effect transistor and a preparation method thereof. The preparation method of the N-type carbon-based field effect transistor comprises the steps that a basic carbon-based field effect transistor of a bottom gate structure is prepared, the bottom gate structure comprises a conductive channel layer, and the conductive channel layer is made of a carbon-based material; cleaning the basic carbon-based field effect transistor and heating the basic carbon-based field effect transistor to remove impurities and groups of the basic carbon-based field effect transistor; soaking the basic carbon-based field effect transistor in a second solution to generate a molecular film on the surface of the conductive channel layer; and drying the soaked basic carbon-based field effect transistor to obtain the N-type carbon-based field effect transistor. Organic molecules are adsorbed on the surface of the carbon-based material through pi-pi non-covalent interaction, a molecular film is formed, electrons are efficiently provided, electron doping of the carbon-based material is achieved, meanwhile, the integrity of the atomic structure of the carbon-based material is kept, and finally the N-type carbon-based field effect transistor is prepared.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to an N-type carbon-based field effect transistor and a method for preparing the same. Background Art

[0002] Traditional silicon-based semiconductor technology has reached its physical limits (such as quantum tunneling effect and short channel effect), and it is difficult to further reduce the size of devices. Carbon-based materials (such as graphene, carbon nanotubes, graphyne, etc.) have higher carrier mobility (for example, the mobility of carbon nanotubes can be more than 10 times that of silicon), which makes it possible to develop nanoscale or even molecular-level devices. At the same time, carbon materials can be bent and stretched, making them suitable for flexible electronic devices and wearable devices.

[0003] The surface of carbon-based materials easily absorbs oxygen or water molecules. These molecules act as electron acceptors and take electrons from carbon-based materials, causing holes to become the majority carriers, so that the field effect transistor constructed with carbon-based materials exhibits P-type dominant characteristics (hole conduction). The stable manufacture of N-type carbon-based field effect transistors is a prerequisite for building carbon-based CMOS circuits. In related technologies, the conductive properties of carbon-based field effect transistors are generally controlled by electric field control or chemical doping. However, the process of electric field control is relatively complicated, and chemical doping destroys the atomic structure of carbon-based materials and reduces their conductive properties.

[0004] Therefore, it is urgent to propose a new method to solve the above technical problems, so as to realize the preparation of N-type carbon-based field effect transistors in a simple, efficient and low-cost manner, while keeping the atomic structure of the carbon-based material intact. Summary of the invention

[0005] The present application discloses an N-type carbon-based field effect transistor and a preparation method thereof, wherein the basic carbon-based field effect transistor is first cleaned and then Non-covalent interactions allow the organic molecules in the second solution to adsorb on the surface of the carbon-based material to form a molecular film to isolate the hole doping of the carbon-based material by water and oxygen in the air, and efficiently provide electrons, thereby achieving electron doping of the carbon-based material while maintaining the integrity of its atomic structure, thereby simply and efficiently realizing the preparation of N-type carbon-based field effect transistors.

[0006] In some embodiments, a method for preparing an N-type carbon-based field effect transistor is provided, comprising: preparing a base carbon-based field effect transistor with a bottom gate structure, the bottom gate structure comprising a conductive channel layer, the conductive channel layer being a carbon-based material; using a first solution to cleanse the base carbon-based field effect transistor, and performing a heat treatment on the cleansed base carbon-based field effect transistor to remove impurities and groups of the base carbon-based field effect transistor; immersing the base carbon-based field effect transistor in a second solution to generate a molecular film on the surface of the conductive channel layer; and performing a drying treatment on the immersed base carbon-based field effect transistor to obtain an N-type carbon-based field effect transistor.

[0007] By using the method for preparing an N-type carbon-based field effect transistor provided in the embodiment of the present application, a basic carbon-based field effect transistor can be generated by using a carbon-based material as a conductive channel layer. The basic carbon-based field effect transistor is cleaned by using a first solution, and the basic carbon-based field effect transistor after the cleaning treatment is heated to remove impurities and groups on the surface of the carbon-based material, so that the surface of the carbon-based material is The conjugated structure can be fully exposed. By immersing the basic carbon-based field effect transistor in the second solution, the organic molecules in the second solution can be combined with the surface of the carbon-based material. Conjugated structure occurs Non-covalent interactions form a molecular film to isolate the hole doping of carbon-based materials by water and oxygen in the air, and efficiently provide electrons, thereby achieving electron doping of carbon-based materials while maintaining the integrity of their atomic structure, and ultimately preparing N-type carbon-based field effect transistors.

[0008] Optionally, a basic carbon-based field effect transistor with a bottom-gate structure is prepared, including: providing a substrate layer, the substrate layer is a doped silicon wafer with a silicon dioxide layer covered on the surface; integrating a carbon-based material on the surface of the silicon dioxide layer to generate a conductive channel layer, the carbon-based material is at least one of graphyne, graphene nanoribbons and carbon nanotubes with semiconductor properties; and preparing a source and a drain on the carbon-based material using a micro-nano processing technology.

[0009] Optionally, the base carbon-based field effect transistor is cleansed using a first solution, and the base carbon-based field effect transistor after the cleansing treatment is subjected to a heat treatment, including: preparing a first solution, wherein the organic solution in the first solution is at least one of N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, methanol, ethanol and toluene; placing the base carbon-based field effect transistor in the first solution, and taking it out after soaking for a first preset time; and performing a heat treatment on the soaked base carbon-based field effect transistor to remove impurities and groups on the surface of the carbon-based material, wherein the groups include at least one of hydroxyl, carboxyl, amino and methyl.

[0010] In this way, the organic solution in the first solution can be used to dissolve the impurities and groups on the surface of the carbon-based material of the basic carbon-based field effect transistor, and the impurities and groups on the surface of the carbon-based material can be further removed by heat treatment, so that the surface of the carbon-based material The conjugated structure can be fully exposed, providing good conditions for the subsequent generation of molecular films.

[0011] Optionally, the first preset time is 1 minute to 5 minutes, the temperature of the first solution is within a first temperature range, and the first temperature range is 50 degrees Celsius to 80 degrees Celsius.

[0012] In this way, by controlling the temperature and immersion time of the first solution, the impurities and groups on the surface of the carbon-based material of the basic carbon-based field effect transistor can be fully dissolved in the organic solution in the first solution, thereby improving the effect of removing impurities and groups on the surface of the carbon-based material.

[0013] Optionally, before performing a heating treatment on the immersed basic carbon-based field effect transistor, the method further includes: immersing the basic carbon-based field effect transistor in a third solution and a fourth solution in sequence, wherein the third solution is an acetone solution and the fourth solution is deionized water.

[0014] In this way, the acetone solution can be used to further dissolve organic impurities on the surface of the carbon-based material, thereby improving the cleaning effect. The acetone solution remaining on the surface of the basic carbon-based field effect transistor can be removed by deionized water, thereby improving the purity of the surface of the basic carbon-based field effect transistor.

[0015] Optionally, the base carbon-based field effect transistor after immersion is subjected to a heat treatment, including: providing an annealing furnace, the interior of the annealing furnace is a vacuum or an inert gas, the inert gas is at least one of nitrogen and argon; placing the base carbon-based field effect transistor in the annealing furnace for heating, the temperature of the annealing furnace is within a second temperature range, and the second temperature range is 150 degrees Celsius to 550 degrees Celsius.

[0016] In this way, impurities and groups on the surface of carbon-based materials can undergo thermal decomposition reaction and decompose into small molecular gases at high temperature, thereby detaching from the surface of carbon-based materials, making the surface of carbon-based materials The conjugated structure can be fully exposed, providing good conditions for the subsequent generation of molecular films.

[0017] Optionally, immersing the basic carbon-based field effect transistor in a second solution includes: preparing the second solution, wherein the organic solution in the second solution is at least one of acridine orange, methylene blue, rhodamine and cyanine derivatives containing electron donor groups; placing the basic carbon-based field effect transistor in the second solution, and taking it out after immersing it for a second preset time, wherein the second preset time is greater than or equal to 5 seconds.

[0018] In this way, the surface of organic molecules in organic solution can be used Conjugated structure, and the surface of carbon-based materials Conjugated structures occur between Non-covalent interactions can achieve self-adsorption of organic molecules, complete the functional modification of carbon-based materials, and generate molecular films.

[0019] Optionally, a drying treatment is performed on the base carbon-based field effect transistor after immersion, including: using a clean gas to purge the surface of the base carbon-based field effect transistor to remove the second solution remaining on the surface of the base carbon-based field effect transistor, and the clean gas is at least one of oxygen, nitrogen, and argon.

[0020] In this way, excess solution on the surface of the carbon-based field effect transistor can be removed, keeping the carbon-based field effect transistor dry.

[0021] In some embodiments, an N-type carbon-based field effect transistor is provided, comprising: a substrate layer, the substrate layer being a doped silicon wafer having a surface covered with a silicon dioxide layer; a conductive channel layer, the conductive channel layer being disposed above the silicon dioxide layer, the conductive channel layer being a carbon-based material; an electrode, the electrode being disposed above the conductive channel layer; and a molecular film, the molecular film covering a first region above the conductive channel layer, the first region being a region on the surface of the conductive channel layer excluding the electrode, the molecular film comprising organic molecules.

[0022] Optionally, the conductive channel layer is at least one of graphyne, graphene nanoribbon and carbon nanotube having semiconductor properties.

[0023] It can be understood that the beneficial effects that can be achieved by the N-type carbon-based field effect transistor provided above can refer to the beneficial effects of the preparation method of the N-type carbon-based field effect transistor and any optional implementation thereof, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 A schematic flow chart of a method for preparing an N-type carbon-based field effect transistor provided in an embodiment of the present application; Figure 2 A schematic diagram of a process for preparing a basic carbon-based field effect transistor provided in an embodiment of the present application; Figure 3 A schematic diagram of a process for cleaning a carbon-based field effect transistor according to an embodiment of the present application; Figure 4A structural diagram of an N-type carbon-based field effect transistor provided in an embodiment of the present application; Figure 5 An example diagram of an experimental test circuit provided in an embodiment of the present application; Figure 6 An example diagram of a transfer characteristic curve of a basic carbon-based field effect transistor provided in an embodiment of the present application; Figure 7 This is an example diagram of the transfer characteristic curve of the N-type carbon-based field effect transistor provided in an embodiment of the present application.

[0026] Reference numerals: 1. Substrate layer; 11. Doped silicon wafer; 12. Silicon dioxide layer; 2. Conductive channel layer; 3. Electrode; 4. Molecular film. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, other embodiments obtained by ordinary technicians in this field without making creative work all belong to the protection scope of the present application.

[0028] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0029] In addition, in the present application, directional terms such as "upper", "lower", "inner" and "outer" are defined relative to the orientation of the components schematically placed in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to the changes in the orientation of the components placed in the drawings.

[0030] In order to facilitate the understanding of the technical solution of the application, the relevant technologies involved in this application are first explained below.

[0031] A carbon-based field effect transistor is a device that uses carbon materials with semiconductor properties as a conductive channel to realize the function of a field effect transistor. A voltage is applied between the gate and the source to form an electric field perpendicular to the conductive channel. The electric field changes the type (electrons or holes) and concentration of carriers in the conductive channel through capacitive coupling. Under the action of the voltage between the source and the drain, the carriers flow along the channel to form a current.

[0032] Carbon-based materials (graphyne, carbon nanotubes, graphene) have high carrier mobility, but due to their small size and large specific surface area, they are very easy to adsorb water and oxygen molecules in the air. As electron acceptors, water and oxygen molecules will take electrons from carbon-based materials, making holes the majority carriers, so that field effect transistors based on carbon-based materials show P-type dominant characteristics. This characteristic makes the preparation of N-type carbon-based field effect transistors challenging.

[0033] The N-type conductive properties of carbon-based field effect transistors can be regulated by electric field regulation or chemical doping, but the electric field regulation process is relatively complicated, and chemical doping destroys the atomic structure of carbon-based materials and reduces their conductive properties. In order to solve the problems existing in the above-mentioned related technologies, the present application embodiment provides an N-type carbon-based field effect transistor and a preparation method thereof, which utilizes the molecular Non-covalent interactions adsorb organic molecules on the surface of carbon-based materials to form a molecular film to isolate the hole doping of carbon-based materials by water and oxygen in the air, and efficiently provide electrons, thereby achieving electron doping of carbon-based materials while maintaining the integrity of their atomic structure, and ultimately preparing N-type carbon-based field effect transistors.

[0034] Figure 1 The schematic diagram of the process for preparing the N-type carbon-based field effect transistor provided in the embodiment of the present application is as follows: Figure 1 The preparation method of the N-type carbon-based field effect transistor of the embodiment of the present application is described in detail. Figure 1 As shown, the method for preparing an N-type carbon-based field effect transistor includes steps S100 to S400.

[0035] Step S100: preparing a basic carbon-based field effect transistor with a bottom-gate structure.

[0036] In some embodiments, the basic carbon-based field effect transistor is a bottom gate structure. In the bottom gate structure, the gate is located on the substrate layer, an insulating layer is deposited on the gate, and a conductive channel layer is formed on the insulating layer, the conductive channel layer is a carbon-based material, and a source and a drain are made on the conductive channel layer, thereby obtaining a basic carbon-based field effect transistor with a bottom gate structure.

[0037] Figure 2 A schematic diagram of a process for preparing a basic carbon-based field effect transistor provided in an embodiment of the present application, such as Figure 2 As shown, the preparation of a basic carbon-based field effect transistor with a bottom-gate structure includes steps S101 to S103.

[0038] Step S101: providing a substrate layer.

[0039] In some embodiments, the substrate layer is a doped silicon wafer with a silicon dioxide layer on its surface. In the process of preparing the substrate layer, a silicon dioxide insulating layer is grown on the surface of the clean doped silicon wafer by any method selected from thermal oxidation, deposition and epitaxial growth to obtain the substrate layer.

[0040] Step S102: Integrate a carbon-based material on the surface of the silicon dioxide layer to generate a conductive channel layer.

[0041] In some embodiments, the carbon-based material may be at least one of graphyne, graphene nanoribbons and carbon nanotubes having semiconductor properties. Among them, graphyne is a new type of carbon material with rich carbon chemical bonds and a large conjugated system. Graphene is a two-dimensional carbon nanomaterial composed of hexagonal carbon atoms. Carbon nanotubes are seamless, hollow tubular objects formed by carbon atoms.

[0042] When the carbon-based material is carbon nanotubes, the carbon-based material can be integrated on the surface of the silicon dioxide layer by chemical vapor deposition. In addition, the conductive channel layer can be formed by depositing a carbon nanotube dispersion into a film by spin coating, spray coating, dip coating or dip-pulling.

[0043] When the carbon-based material is graphene or graphyne, the carbon-based material can be stripped from the graphite surface by mechanical stripping and transferred to the surface of the silicon dioxide layer to generate a conductive channel layer. In addition, a chemical deposition method can be used to grow graphene or graphyne on the surface of a metal substrate at high temperature using a carbon-containing gas, and then transfer it to the surface of the silicon dioxide layer to generate a conductive channel layer. The present application does not specifically limit the method of integrating carbon-based materials on the surface of the silicon dioxide layer.

[0044] Step S103: Prepare source and drain electrodes on the carbon-based material using micro-nano processing technology.

[0045] In some embodiments, a layer of photoresist is spin-coated on the surface of the carbon-based material, and a photochemical reaction is caused in a specific area of ​​the photoresist by means of an ultraviolet exposure process (for example, ultraviolet exposure using a mask). The exposed photoresist is developed to remove the photoresist in the area where the source and drain are to be formed, and a metal (such as gold, palladium, titanium, chromium, etc.) is deposited on the surface of the carbon-based material by physical vapor deposition. The remaining photoresist is then removed by a stripping process to prepare the source and drain on the carbon-based material.

[0046] Step S200: using a first solution to clean the basic carbon-based field effect transistor, and performing a heat treatment on the cleaned basic carbon-based field effect transistor.

[0047] In some embodiments, there are impurities on the surface of the basic carbon-based field effect transistor, which will affect the adsorption force of organic molecules on the surface of the carbon-based material, reduce the efficiency and quality of organic molecule adsorption film formation, and reduce the efficiency of charge transfer between molecules. The basic carbon-based field effect transistor is cleaned by using the first solution and heated to remove impurities and groups, so that the surface of the carbon-based material The conjugated structure can be fully exposed, providing good conditions for the subsequent generation of molecular films.

[0048] Figure 3 A schematic diagram of a process for cleaning a carbon-based field effect transistor according to an embodiment of the present application is shown in FIG. Figure 3 As shown, the cleaning process of the carbon-based field effect transistor includes steps S201 to S203.

[0049] Step S201, preparing a first solution.

[0050] In some embodiments, the organic solution in the first solution is at least one of N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, methanol, ethanol and toluene. In this way, the organic solution in the first solution can dissolve part of the organic matter on the surface of the basic carbon-based field effect transistor to achieve the purpose of removing impurities.

[0051] Step S202: placing the basic carbon-based field effect transistor in a first solution, and taking it out after soaking it for a first preset time.

[0052] In some embodiments, the temperature of the first solution is controlled within a first temperature range, the basic carbon-based field effect transistor is placed in the first solution, and taken out after being immersed for a first preset time, wherein the first preset time is 1 minute to 5 minutes, and the first temperature range is 50 degrees Celsius to 80 degrees Celsius.

[0053] Exemplarily, the temperature of the first solution is set to 55 degrees Celsius, and the basic carbon-based field effect transistor is placed in the first solution and immersed for 2 minutes and then taken out to remove impurities on the surface of the basic carbon-based field effect transistor.

[0054] Step S203, performing a heating treatment on the soaked basic carbon-based field effect transistor.

[0055] In some embodiments, since the impurities and groups on the surface of the basic carbon-based field effect transistor have a certain adsorption force, by performing a heating treatment on the basic carbon-based field effect transistor, the thermal motion of the molecules can be intensified, so that the impurities and groups obtain sufficient energy to overcome the adsorption force, thereby desorbing and decomposing from the surface of the carbon-based material, and the decomposed impurities and groups are separated from the basic carbon-based field effect transistor in a gaseous form to remove the impurities and groups on the surface of the carbon-based material. Wherein, the group includes at least one of a hydroxyl group, a carboxyl group, an amino group and a methyl group.

[0056] In some embodiments, before performing a heat treatment on the immersed base carbon-based field effect transistor, the base carbon-based field effect transistor needs to be immersed in a third solution and a fourth solution in sequence, wherein the third solution is an acetone solution and the fourth solution is deionized water.

[0057] It should be understood that acetone is an organic solvent with strong dissolving power, which can effectively dissolve grease, organic residues and some polymer impurities on the surface of the basic carbon-based field effect transistor. Deionized water is a high-purity water that can remove water-soluble impurities on the surface of the basic carbon-based field effect transistor. In this way, by immersing the basic carbon-based field effect transistor in the third solution and the fourth solution in turn, the cleanliness of the basic carbon-based field effect transistor can be further improved.

[0058] In some embodiments, an annealing furnace can be used to perform a heat treatment on the basic carbon-based field effect transistor. An annealing furnace is first provided, and the interior of the annealing furnace is a vacuum or an inert gas, and the inert gas is at least one of nitrogen and argon. In this way, it is possible to prevent the carbon-based material from undergoing an oxidation reaction with oxygen at high temperature, resulting in changes in the structure and performance of the carbon-based material. In a specific embodiment, providing an annealing furnace specifically includes: filling the annealing furnace with an inert gas, but the inert gas maintains a flowing state, so that the gas enters from one end of the annealing furnace and exits from the other end. In another specific embodiment, providing an annealing furnace specifically includes: making the interior of the annealing furnace in a vacuum state.

[0059] Furthermore, the basic carbon-based field effect transistor is placed in an annealing furnace and heated. The temperature of the annealing furnace is within a second temperature range, which is 150 degrees Celsius to 550 degrees Celsius. In this way, impurities and groups on the surface of the carbon-based material can undergo a thermal decomposition reaction and decompose into small molecular gases at high temperatures, thereby detaching from the surface of the carbon-based material, making the surface of the carbon-based material The conjugated structure can be fully exposed, providing good conditions for the subsequent generation of molecular films.

[0060] Step S300: immersing the basic carbon-based field effect transistor in a second solution.

[0061] In some embodiments, a second solution needs to be prepared. The organic solution in the second solution is at least one of acridine orange, methylene blue, rhodamine and cyanine derivatives containing an electron donor group. The basic carbon-based field effect transistor is placed in the second solution and taken out after being immersed for a second preset time, and the second preset time is greater than or equal to 5 seconds.

[0062] By immersing the basic carbon-based field effect transistor in a second solution, the organic molecules in the second solution can be connected by molecular The organic molecules are adsorbed on the surface of the carbon-based material by non-covalent interactions to form a molecular film. In this way, through the functional modification of the carbon-based material, the precise functionalization of the organic molecules on the carbon-based material can be achieved, effectively avoiding the disadvantage of non-selective coverage. Specifically, the organic solution in the second solution is Solutions of conjugated structures and electron donor groups.

[0063] Specifically, the organic solution in the second solution is an organic solution containing a conjugated structure and an electron donor group.

[0064] Step S400: performing a drying process on the soaked basic carbon-based field effect transistor.

[0065] Since the second solution remains on the surface of the base carbon-based field effect transistor after immersion, it is necessary to perform a drying process on the base carbon-based field effect transistor after immersion to obtain an N-type carbon-based field effect transistor.

[0066] In some embodiments, the surface of the base carbon-based field effect transistor is purged with a clean gas to remove the second solution remaining on the surface of the base carbon-based field effect transistor, and the clean gas is at least one of oxygen, nitrogen, and argon. In this way, the excess solution on the surface of the carbon-based field effect transistor can be removed to keep the carbon-based field effect transistor dry.

[0067] It can be seen from the above technical solution that the preparation method of the N-type carbon-based field effect transistor provided in the embodiment of the present application can use the carbon-based material as the conductive channel layer to generate a basic carbon-based field effect transistor. The basic carbon-based field effect transistor is cleaned and heated by using the first solution to remove impurities and groups on the surface of the carbon-based material, so that the surface of the carbon-based material The conjugated structure can be fully exposed. By immersing the basic carbon-based field effect transistor in the second solution, the organic molecules in the second solution can be combined with the surface of the carbon-based material. Conjugated structure occurs Non-covalent interactions form a molecular film to isolate the hole doping of carbon-based materials by water and oxygen in the air, and efficiently provide electrons, thereby achieving electron doping of carbon-based materials while maintaining the integrity of their atomic structure, and ultimately preparing N-type carbon-based field effect transistors.

[0068] Figure 4 This is a structural diagram of an N-type carbon-based field effect transistor provided in an embodiment of the present application.

[0069] The present application also provides an N-type carbon-based field effect transistor. Figure 4As shown, the N-type carbon-based field effect transistor includes a substrate layer 1, a conductive channel layer 2, an electrode 3 and a molecular film 4. Among them, the substrate layer 1 is a doped silicon wafer 11 with a silicon dioxide layer 12 on the surface, the conductive channel layer 2 is arranged on the silicon dioxide layer 12, and the conductive channel layer 2 is a carbon-based material; the electrode 3 is arranged on the conductive channel layer; the molecular film 4 covers the first area of ​​the conductive channel layer 2, and the first area is the area on the surface of the conductive channel layer 2 except the electrode 3, and the molecular film 4 includes organic molecules containing a conjugated structure and an electron donor group. The conductive channel layer 2 is at least one of graphyne, graphene nanoribbons and carbon nanotubes with semiconductor properties.

[0070] It can be understood that the beneficial effects that can be achieved by the N-type carbon-based field effect transistor provided above can refer to the beneficial effects of the preparation method of the N-type carbon-based field effect transistor and any optional implementation thereof, and will not be repeated here.

[0071] Figure 5 This is an example diagram of an experimental test circuit provided in an embodiment of the present application. Figure 6 This is an example diagram of the transfer characteristic curve of the basic carbon-based field effect transistor provided in the embodiment of the present application, Figure 7 This is an example diagram of the transfer characteristic curve of the N-type carbon-based field effect transistor provided in the embodiment of the present application. In order to make the technical scheme and technical effect of the present invention clearer, the following is combined with Figure 5 , Figure 6 and Figure 7 The present invention is described in further detail.

[0072] Step 1: Prepare a basic carbon-based field effect transistor with a bottom-gate structure, wherein the carbon-based material of the basic carbon-based field effect transistor is a carbon nanotube with semiconductor properties.

[0073] Step 2: Clean the basic carbon-based field effect transistor with ethanol, acetone and deionized water in sequence.

[0074] Step 3: Place the cleaned basic carbon-based field effect transistor into an annealing furnace and anneal it in a vacuum environment at 300 degrees Celsius for 60 minutes.

[0075] Step 4: Connect the experimental test circuit to test the transfer characteristics of the basic carbon-based field effect transistor.

[0076] like Figure 5As shown, the experimental test circuit connected in step 4 specifically includes: connecting the source S of the basic carbon-based field effect transistor to the negative electrode of the first power supply V1, connecting the drain D of the basic carbon-based field effect transistor to the positive electrode of the first power supply V1, and setting an ammeter between the positive electrode of the first power supply V1 and the drain D. Connecting the gate G of the basic carbon-based field effect transistor to the negative electrode of the second power supply V2, connecting the positive electrode and the drain of the second power supply V2 to the first node N, and the first node N is grounded.

[0077] During the test, the source voltage and drain voltage were fixed at -0.5V, and the gate voltage was gradually increased from -30V to 30V in steps of 0.5V. The current values ​​at different gate voltages were recorded. The test curve of the basic carbon-based field effect transistor was drawn, and then the Figure 6 Transfer characteristic curves of carbon-based field effect transistors. Figure 6 In the figure, under negative gate voltage (-20 V), the hole transport current is much larger than the electron transport current under positive gate voltage (20 V). In addition, at zero gate voltage, the conductive channel is mainly conducted by holes.

[0078] Step 5: Immerse the basic carbon-based field effect transistor annealed in step 3 in a solution containing rhodamine B and take it out after 15 seconds to generate a molecular film.

[0079] Step 6: Use nitrogen to blow dry the liquid remaining on the surface of the basic carbon-based field effect transistor to obtain an N-type carbon-based field effect transistor.

[0080] Step 7: Connect the experimental test circuit to test the transfer characteristics of the N-type carbon-based field effect transistor.

[0081] According to the circuit connection method and voltage regulation method in step 4, the transfer characteristics of the N-type carbon-based field effect transistor are tested, and the test curve of the N-type carbon-based field effect transistor is drawn, thereby obtaining Figure 7 Transfer characteristic curve of N-type carbon-based field effect transistor. Figure 7 In the figure, under negative gate voltage (-20 V), the hole transport current is much smaller than the electron transport current under positive gate voltage (20 V). In addition, at zero gate voltage, the conductive channel is mainly conducted by electrons.

[0082] By comparison Figure 6 Carbon-based field effect transistors and Figure 7The transfer characteristic curve of the N-type carbon-based field effect transistor in the figure shows that the electron transfer characteristics of the carbon-based field effect transistor with organic molecular film are greatly improved compared with the carbon-based field effect transistor without organic molecular film. It can be seen that the molecular film can isolate the water and oxygen in the air from the hole doping of the carbon-based material and efficiently provide electrons, thereby achieving the electron doping of the carbon-based material while maintaining the integrity of its atomic structure, and realizing the preparation of the N-type carbon-based field effect transistor in a simple and efficient way.

[0083] It should be noted that those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope of the present application is indicated by the claims.

[0084] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for preparing an N-type carbon-based field effect transistor, characterized in that: include: Prepare a basic carbon-based field effect transistor with a bottom-gate structure, wherein the bottom-gate structure includes a conductive channel layer, and the conductive channel layer is a carbon-based material; Using a first solution to clean the basic carbon-based field effect transistor, and performing a heat treatment on the basic carbon-based field effect transistor after the cleaning treatment to remove impurities and groups of the basic carbon-based field effect transistor; immersing the basic carbon-based field effect transistor in a second solution to form a molecular film on the surface of the conductive channel layer; The immersed basic carbon-based field effect transistor is dried to obtain an N-type carbon-based field effect transistor.

2. The method for preparing an N-type carbon-based field effect transistor according to claim 1, characterized in that: The method for preparing a bottom-gate structured basic carbon-based field effect transistor comprises: Providing a substrate layer, wherein the substrate layer is a doped silicon wafer with a silicon dioxide layer covering the surface; Integrating a carbon-based material on the surface of the silicon dioxide layer to generate the conductive channel layer, wherein the carbon-based material is at least one of graphyne, graphene nanoribbons and carbon nanotubes having semiconductor properties; A source electrode and a drain electrode are prepared on the carbon-based material by using a micro-nano processing technology.

3. The method for preparing an N-type carbon-based field effect transistor according to claim 1, characterized in that: The step of using the first solution to clean the base carbon-based field effect transistor and performing a heating treatment on the base carbon-based field effect transistor after the cleaning treatment comprises: preparing a first solution, wherein the organic solvent in the first solution is at least one of N-methylpyrrolidone, tetrahydrofuran, chloroform, dichloromethane, methanol, ethanol and toluene; Placing the basic carbon-based field effect transistor in the first solution and taking it out after soaking it for a first preset time; The immersed carbon-based field effect transistor is subjected to a heating treatment to remove impurities and groups on the surface of the carbon-based material, wherein the groups include at least one of hydroxyl, carboxyl, amino and methyl groups.

4. The method for preparing an N-type carbon-based field effect transistor according to claim 3, characterized in that: The first preset time is 1 minute to 5 minutes, the temperature of the first solution is within a first temperature range, and the first temperature range is 50 degrees Celsius to 80 degrees Celsius.

5. The method for preparing an N-type carbon-based field effect transistor according to claim 3, characterized in that: Before performing a heating treatment on the immersed carbon-based field effect transistor, the method further comprises: The basic carbon-based field effect transistor is sequentially immersed in a third solution and a fourth solution, wherein the third solution is an acetone solution and the fourth solution is deionized water.

6. The method for preparing an N-type carbon-based field effect transistor according to claim 3, characterized in that: The step of performing a heating treatment on the immersed carbon-based field effect transistor comprises: Providing an annealing furnace, wherein the interior of the annealing furnace is a vacuum or an inert gas, and the inert gas is at least one of nitrogen and argon; The basic carbon-based field effect transistor is placed in the annealing furnace for heating, wherein the temperature of the annealing furnace is within a second temperature range, and the second temperature range is 150 degrees Celsius to 550 degrees Celsius.

7. The method for preparing an N-type carbon-based field effect transistor according to claim 1, characterized in that: The step of immersing the basic carbon-based field effect transistor in a second solution comprises: preparing a second solution, wherein the organic solution in the second solution is at least one of acridine orange, methylene blue, rhodamine and cyanine derivatives containing an electron donor group; The basic carbon-based field effect transistor is placed in a second solution and taken out after being immersed for a second preset time, wherein the second preset time is greater than or equal to 5 seconds.

8. The method for preparing an N-type carbon-based field effect transistor according to claim 1, characterized in that: The step of performing a drying process on the soaked carbon-based field effect transistor comprises: The surface of the base carbon-based field effect transistor is purged with a clean gas to remove the second solution remaining on the surface of the base carbon-based field effect transistor, and the clean gas is at least one of oxygen, nitrogen, and argon.

9. An N-type carbon-based field effect transistor, characterized in that: include: A substrate layer (1), wherein the substrate layer (1) is a doped silicon wafer (11) with a silicon dioxide layer (12) covering the surface thereof; A conductive channel layer (2), the conductive channel layer (2) being arranged above the silicon dioxide layer (12), and the conductive channel layer (2) being a carbon-based material; An electrode (3), the electrode (3) being arranged on the conductive channel layer (2); A molecular film (4), the molecular film (4) covers a first region of the conductive channel layer (2), the first region being a region on the surface of the conductive channel layer (2) excluding the electrode (3), the molecular film (4) comprising organic molecules.

10. The N-type carbon-based field effect transistor according to claim 9, characterized in that: The conductive channel layer (2) is at least one of graphyne, graphene nanoribbons and carbon nanotubes having semiconductor properties.

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