Diode device based on single carbon nanotube structure, and manufacturing method therefor

Abstract

Provided in the present invention are a diode device based on a single carbon nanotube, and a manufacturing method therefor. The diode device is either a Schottky diode or a p-n junction diode. The Schottky diode consists of a metal end and a semiconductor end, and is formed by axial tailoring, wherein the metal end has no band gap, the semiconductor end has a band gap greater than 0, and the metal end and the semiconductor end come into contact to form a Schottky junction. In the p-n junction diode, one end of a carbon nanotube is doped with boron to form a p-type region, the other end is tailored to introduce dangling electrons to form an n-type region, and a p-n junction is formed at a contact interface. The diode device and the manufacturing method therefor of the present invention solve the difficult problem of forming regions having different conductive properties on a single nanotube, thus break through the size constraints of existing semiconductor processes, and achieve nanoscale diode devices having a diameter less than a few nanometers or even less than one nanometer, thereby providing a new solution for miniaturized electronic devices.

Description

Diode device based on single carbon nanotube structure and manufacturing method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic devices, in particular to a diode device based on single carbon nanotube structure and manufacturing method thereof. BACKGROUND

[0002] With the development of integrated circuits towards higher density, lower power consumption and higher speed, traditional semiconductor materials and devices face performance limitations due to size effects. Nanoscale diodes have the characteristics of being lighter, smaller, more efficient and extremely low power consumption, which can meet the large computing performance requirements of future artificial intelligence chips and learning. Single nanotube diodes are suitable for extremely miniaturized electronic devices, and due to their excellent electrical, mechanical and thermal properties, they become the ideal candidate for the next generation of electronic devices. The electron mobility of single carbon nanotubes is very high, far exceeding traditional semiconductor materials, which can achieve high-speed switching and rapid response. And the conductivity of single carbon nanotubes is close to metal, which has obvious advantages in low resistance applications. And it has high strength and flexibility, high efficiency of electron-hole recombination, low power consumption, low noise and other characteristics, making single carbon nanotube diodes have broad application prospects in future microelectronics, nanoelectronics, optoelectronic devices, high-performance devices, sensors and flexible electronic devices.

[0003] The synthesis technology of carbon nanotubes is constantly optimized, and single carbon nanotubes with high purity, single chirality and high crystallinity can be prepared. These high-quality carbon tubes lay the foundation for the improvement of device performance. High-precision electron beam lithography and chemical vapor deposition and other micro-nano processing technologies can realize efficient contact between carbon tubes and electrodes.

[0004] The difficulty in designing single nanotube diodes lies in forming a stable Schottky junction or p-n junction between the metal material part and the semiconductor material in the same nanotube.

[0005] It should be noted that the information disclosed in the above background section is only for understanding the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] The main purpose of the present application is to overcome the defects and difficulties of the above background technology, and to provide a diode device based on single carbon nanotube structure and manufacturing method thereof.

[0007] To achieve the above purpose, the present application adopts the following technical solutions:

[0008] In the first aspect of the present application, a diode device based on single carbon nanotube structure comprises:

[0009] a single carbon nanotube;

[0010] a metal end, formed by cutting one end of the carbon nanotube along the axial direction, having metallic property and no band gap in its energy band structure;

[0011] a semiconductor end, formed by the other end of the carbon nanotube, keeping the complete chirality, having semiconductor property and having a band gap greater than 0 in its energy band structure;

[0012] a Schottky junction, formed at the contact interface between the metal end and the semiconductor end, forming a depletion region at the interface, and allowing current to flow from the metal end to the semiconductor end under forward bias condition, while preventing current from passing due to the potential barrier formed by the depletion region under reverse bias condition;

[0013] electrodes, assembled on the metal end and the semiconductor end.

[0014] Further, the carbon nanotube has chirality (n, m), m = 0 or n - m ≠ 3q, wherein n and m are integers, q is an integer, and n > m.

[0015] Further, the carbon nanotube has a radius of 0.4-30 nm.

[0016] Further, the energy band of the semiconductor end has a band gap of 0.1-2.0 eV.

[0017] In the second aspect of the present application, a method for manufacturing the single carbon nanotube structure-based diode device, comprising the following steps:

[0018] dispersing the carbon nanotube in a solvent;

[0019] dropping or spraying the dispersed carbon nanotube solution on a clean substrate and drying it to form a uniform carbon nanotube film;

[0020] cutting one end of the carbon nanotube along the axial direction to form a metal end, and keeping the other end of the carbon nanotube as a complete nanotube structure to form a semiconductor end; the contact interface between the metal end and the semiconductor end forms a Schottky junction;

[0021] assembling electrodes on the metal end and the semiconductor end.

[0022] In the third aspect of the present application, a single carbon nanotube structure-based p-n junction diode device, comprising:

[0023] a single carbon nanotube, having different conductive property regions;

[0024] a p-type semiconductor end formed by one end of the carbon nanotube, doped with boron atoms to have p-type semiconductor properties;

[0025] an n-type semiconductor end formed by cutting the other end of the carbon nanotube along the axial direction, introduced with extra dangling electrons, having n-type semiconductor properties;

[0026] a p-n junction formed at the contact interface between the p-type semiconductor end and the n-type semiconductor end, a depletion region formed at the interface, and under forward bias condition, allowing current to flow from the n-type semiconductor end to the p-type semiconductor end, and under reverse bias condition, the current is blocked due to the potential barrier formed by the depletion region;

[0027] electrodes assembled on the p-type semiconductor end and the n-type semiconductor end.

[0028] Further, the carbon nanotube has chirality (n, m), m=0 or n-m≠3q, wherein n and m are integers, q is an integer, and n>m.

[0029] Further, the carbon nanotube has a radius of 0.4-30 nm.

[0030] In the fourth aspect of the present application, a method for manufacturing the single carbon nanotube structure-based p-n junction diode device includes the following steps:

[0031] dispersing the carbon nanotube in a solvent;

[0032] drop-casting or spray-casting the dispersed carbon nanotube solution on a clean substrate and drying to form a uniform carbon nanotube film;

[0033] performing boron atom doping on one end of the carbon nanotube to form a p-type semiconductor end, and cutting the other end of the carbon nanotube along the axial direction to form an n-type semiconductor end; the contact interface between the p-type semiconductor end and the n-type semiconductor end forms a p-n junction;

[0034] assembling electrodes on the p-type semiconductor end and the n-type semiconductor end.

[0035] Further, the assembling electrodes on the p-type semiconductor end and the n-type semiconductor end specifically includes: using electron beam lithography, exposing according to the designed electrodes, forming a pattern after development, forming electrodes through metal deposition and stripping photoresist, and performing heat treatment and annealing to ensure the contact between the electrodes and the carbon nanotube.

[0036] The present application has the following beneficial effects:

[0037] The application provides a diode device based on a single carbon nanotube structure and an atomic-level manufacturing method thereof, and successfully realizes a high-performance and low-power Schottky diode and a p-n junction diode on a nanometer scale. The design utilizes the unique properties of the carbon nanotube, forms a metal end and a semiconductor end on the single carbon nanotube through accurate tailoring and doping technology, and further constructs a stable Schottky junction, or forms a p-type semiconductor end on one end of the single carbon nanotube through doping of an acceptor impurity, forms an n-type semiconductor end on the other end through tailoring to introduce additional suspended electrons, and further constructs a stable p-n junction. The diode device based on the single carbon nanotube structure of the application not only breaks through the size limitation of the existing semiconductor process on a nanometer scale, but also solves the problem of forming regions with different conductive properties on the same nanotube, realizes a nanometer-scale diode device with a diameter of less than a few nanometers, even less than one nanometer, and breaks through the size bottleneck of the existing semiconductor process on a nanometer scale. In addition, the diode device of the application exhibits low impedance when forward biased, allowing current to flow smoothly, and exhibits high impedance due to the potential barrier formed by the depletion region when reverse biased, thereby having ideal diode rectification characteristics. The innovative device scheme and manufacturing method provide new possibilities for applications in the fields of microelectronics, nanoelectronics and the like, and are expected to promote the development and application of related technologies.

[0038] Other beneficial effects in the embodiments of the application will be further described below. BRIEF DESCRIPTION OF DRAWINGS

[0039] Fig. 1 is a structure schematic diagram of a Schottky diode device based on a single carbon nanotube according to an embodiment of the application.

[0040] Fig. 2 is a band structure diagram of a carbon nanotube of the anode of the Schottky diode according to an embodiment of the application.

[0041] Fig. 3 is a band structure diagram of a complete carbon nanotube of the cathode of the Schottky diode according to an embodiment of the application.

[0042] Fig. 4 is a structure schematic diagram of a p-n diode device based on a single carbon nanotube according to an embodiment of the application.

[0043] Fig. 5 is a band structure diagram of a carbon nanotube n-type semiconductor of the anode of the p-n junction diode according to an embodiment of the application.

[0044] Fig. 6 is a band structure diagram of a carbon nanotube p-type semiconductor of the boron-doped cathode of the p-n junction diode according to an embodiment of the application. DETAILED DESCRIPTION

[0045] The embodiments of the application are described in detail below. It should be emphasized that the following description is only exemplary, and is not intended to limit the scope of the application and its applications.

[0046] It is to be noted that when an element is referred to as being "on" or "connected to" another element, it can be directly on the other element or indirectly on the other element with intervening elements present. In addition, the connection can be fixed or it can be a removable connection.

[0047] It is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, specify relative positions and orientations as shown in the drawings, and are used only for the purpose of illustrating the application and simplifying the description, and are not intended to limit the scope of the application to the positions and orientations described. Thus, the application is not limited to the relative positions and orientations described and shown in the drawings.

[0048] In addition, the terms "first", "second", "third", etc. are used herein only to describe different instances, and are not used to indicate or imply relative importance or a number of instances. Thus, a feature with a "first" and a "second" designation can include one or more of the features. In the description of embodiments of the application, the meaning of "a plurality" is two or more, unless explicitly specified otherwise.

[0049] Embodiments of the application provide a single carbon nanotube based diode device. By taking advantage of the unique properties of carbon nanotubes, a metal end and a semiconductor end are realized on the same carbon nanotube through tailoring and doping techniques, and a stable Schottky junction or p-n junction is constructed, which can be used to fabricate extremely miniaturized electronic devices. In a single carbon nanotube, a p-n junction or a Schottky junction exists in the middle of the carbon tube, and the entire structure can be used to make a carbon nanotube diode. Such a diode can be used for rectification and other nonlinear elements in electronic circuits.

[0050] Referring to FIG. 1, embodiments of the application provide a single carbon nanotube based diode device, which includes: a single carbon nanotube; a metal end 1 formed by axially tailoring one end of the carbon nanotube, having metallic properties, and having no band gap in its energy band structure; a semiconductor end 3 formed by the other end of the carbon nanotube, maintaining complete chirality, having semiconductor properties, and having a band gap greater than 0 in its energy band structure; a Schottky junction 2 formed at the contact interface between the metal end 1 and the semiconductor end 3, forming a depletion region at the interface, and allowing current to flow from the metal end to the semiconductor end under forward bias conditions, and preventing current from passing due to the potential barrier formed by the depletion region under reverse bias conditions; electrodes (not shown) assembled on the metal end 1 and the semiconductor end 2.

[0051] The Schottky junction 2 is formed by the direct contact of the metal end 1 with the semiconductor end 3. At this interface, due to the difference in work function of the two materials, the electrons redistribute at the interface, forming a depletion region. The device of the present embodiment can be configured as a diode by the formation of the Schottky junction 2.

[0052] For single-walled chiral carbon nanotubes, when the chiral vector is m=0 or n-m≠3q (q is an integer, and n>m), the carbon nanotube has semiconducting properties. When the carbon nanotube is cut along the axial direction to form a nanobelt with curvature, or a line defect is formed, due to the dangling electrons of the edge atoms, the carbon nanotube is converted to a metallic property. In a single carbon nanotube, there are both a complete carbon nanotube and a cut carbon tube portion, and a stable Schottky junction can be formed at the junction of the two portions.

[0053] As shown in Figure 1, the embodiment is based on a single carbon nanotube diode device, and the metal end 1 and the semiconductor end 2 of the diode are based on the same carbon nanotube. The metal end 1 is a nanobelt with curvature cut along the axial direction. The semiconductor end 2 is a complete chiral carbon nanotube. The metal end 1 is the anode (positive electrode), and the semiconductor end 2 is the cathode (negative electrode). The semiconductor end 2 is in contact with the metal end 1. The chiral of the semiconductor carbon nanotube is (n,m), and the types include m=0 and a carbon nanotube with a radius of 0.4-30 nm and n-m≠3q (q is an integer, and n>m). The method of forming the axial cut of the carbon nanotube metal end includes but is not limited to laser-induced cutting, arc discharge, and molecular knife cutting.

[0054] Referring to Figure 4, the embodiment of the present application also provides a single carbon nanotube structure-based p-n junction diode device, which includes: a single carbon nanotube having different conductive property regions; a p-type semiconductor end 6 formed by one end of the carbon nanotube, doped with boron atoms to have p-type semiconductor properties; an n-type semiconductor end 4 formed by partially cutting the other end of the carbon nanotube along the axial direction, introducing additional dangling electrons, and having n-type semiconductor properties; a p-n junction 5 formed at the contact interface between the p-type semiconductor end 6 and the n-type semiconductor end 4, forming a depletion region at the interface, and allowing current to flow from the n-type semiconductor end 4 to the p-type semiconductor end 6 under forward bias conditions, and preventing current from passing due to the potential barrier formed by the depletion region under reverse bias conditions; electrodes (not shown) assembled on the p-type semiconductor end 6 and the n-type semiconductor end 4.

[0055] When a p-type semiconductor and an n-type semiconductor are in contact, due to the recombination of electrons and holes, a p-n junction will be formed at the interface. The formed p-n junction exhibits low impedance under forward bias and high impedance under reverse bias, and is the basic structure of semiconductor devices such as diodes.

[0056] For single-walled chiral carbon nanotubes, when the chiral vector is m = 0 or n - m ≠ 3q (q is an integer and n > m), the carbon nanotube has a semiconducting property. When an electric field is applied to the axially cut carbon nanotube, the material will exhibit an n-type semiconductor property due to the movement of electrons. The boron atom-doped carbon nanotube will exhibit a P-type semiconductor property due to the lack of valence electrons. The combination of n-type and P-type semiconductors can form a p-n junction.

[0057] The present application forms a Schottky diode or a p-n junction diode in a single carbon nanotube by means of carbon nanotube cutting and doping. The single carbon nanotube diode device proposed in the present application can be used to realize extremely miniaturized electronic devices.

[0058] Example 1

[0059] The example of Figure 1 is a Schottky diode structure design based on a single carbon nanotube. The structure contains a carbon nanotube, one end of which is a complete nanotube structure and the other end is an axially cut nanotube structure (the structure is close to a curled nanobelt). The anode end shown in Figure 1 is an axially cut nanotube, which has a metallic property (as shown in Figure 2, the band gap disappears after cutting and changes to a metallic property). The cathode end shown in Figure 1 is a complete nanotube structure, which has a semiconducting property (as shown in Figure 3, the energy band has a 1.1 eV band gap, which is a semiconductor). The Schottky junction shown in Figure 1 is the connection of the metal material of the anode and the semiconductor material of the cathode, and a Schottky junction with a potential barrier of about 1 eV is formed at the interface. When forward biased, the current flows from the metal end (anode) to the semiconductor end (cathode), i.e. the current flows out of the cathode, and the diode is turned on. When reverse biased, due to the potential barrier of the Schottky junction, the current is blocked and almost no current passes through the diode, and the diode is turned off.

[0060] Example 2

[0061] The example of FIG. 4 is a single carbon nanotube based p-n junction diode structure design. The structure contains a single carbon nanotube, one end is a boron-doped carbon nanotube structure with p-type semiconductor properties; the other end is an axially cut nanotube structure (structure close to a curled nanobelt). The positive electrode end shown in FIG. 4 is an axially cut carbon nanotube, which introduces additional dangling electrons due to cutting, and has n-type conductive material properties in an electric field. As shown in FIG. 5, the cutting structure causes the material to move down in the electric field, exhibiting charge carrier semiconductor properties. The negative electrode end shown in FIG. 4 is a boron-doped complete nanotube structure with p-type semiconductor properties. As shown in FIG. 6, boron atom doping causes the band to move up, exhibiting hole carrier semiconductor properties. The p-n junction shown in FIG. 4 is the connection of the n-type material of the positive electrode and the p-type semiconductor material of the negative electrode, forming a p-n junction with charge carriers and hole carriers at the interface. When forward biased, the current flows from the n-type semiconductor end (positive electrode) to the p-type semiconductor end (negative electrode), i.e. the current flows out of the negative electrode, and the diode is turned on. When reverse biased, the current is blocked due to the depletion layer of the p-n junction, and almost no current passes through the diode, and the diode is turned off.

[0062] Fabrication Example

[0063] Cutting carbon nanotubes:

[0064] Carbon nanotube selection: select carbon nanotubes with a radius of 0.4-30 nm, chirality of m=0 or n-m≠3q, or boron-doped single-walled carbon nanotubes:

[0065] Disperse the nanotubes: disperse the carbon nanotubes in a solvent (ethanol, isopropanol, water, etc.) to avoid agglomeration.

[0066] Prepare the substrate: drop or spray the dispersed carbon nanotube solution onto a clean substrate (such as a silicon wafer, glass sheet, etc.) and allow it to dry to form a uniform distribution of carbon nanotube film.

[0067] Cutting process of laser atomic-scale fabrication method: select femtosecond laser or attosecond laser atomic-scale rapid cold cutting fabrication method, and precisely position the carbon nanotube area to be cut by microscope or other imaging equipment. Control the movement path of the laser beam on the sample surface, so that it scans and cuts the carbon nanotube along the predetermined track. Due to the local heating of the laser beam on the carbon nanotube, the material vaporizes or breaks, thereby achieving cutting. Avoid excessive damage to the adjacent area during the cutting process.

[0068] Characterize the cutting effect: after cutting, clean the sample to remove debris and impurities generated during the cutting process. Use nanoscale high-resolution microscopy (such as scanning electron microscopy SEM, transmission electron microscopy TEM, high-resolution scanning transmission electron microscopy STEM, etc.) to characterize the cutting effect.

[0069] Electrode assembly:

[0070] Position the single carbon nanotube and record the position. Design the electrode to ensure that the electrode contact area coincides with the carbon nanotube. Select appropriate electrode materials (such as gold, platinum, chromium, titanium, etc.) to ensure good contact with the carbon nanotube.

[0071] Use atomic-scale manufacturing methods such as electron beam lithography to expose according to the designed electrode, and after development, a pattern is formed in the exposed area. Through metal deposition and stripping of photoresist, high-precision electrodes are formed.

[0072] Finally, heat treatment and annealing are performed to ensure the contact between the electrode and the carbon nanotube.

[0073] In summary, the present application proposes a diode device based on single carbon nanotube structure and its atomic-scale manufacturing method, which successfully realizes high-performance and low-power Schottky diode and p-n junction diode on a nanoscale. This design takes advantage of the unique properties of carbon nanotubes, through precise atomic-scale tailoring and doping technology, to form metal ends and semiconductor ends on a single carbon nanotube, and then build a stable Schottky junction, or by doping acceptor impurities on one end of a single carbon nanotube to form a p-type semiconductor end, and by tailoring to introduce additional suspended electrons on the other end to form an n-type semiconductor end, and then build a stable p-n junction. The diode device based on single carbon nanotube structure of the present application not only breaks through the size limit of existing semiconductor process on a nanoscale, but also solves the problem of forming different conductive property regions on the same nanotube, realizing a nanoscale diode device with a diameter of less than a few nanometers, even less than one nanometer, breaking through the size bottleneck of existing semiconductor process on a nanoscale. In addition, the diode device of the present application exhibits low impedance when forward biased, allowing current to flow smoothly, and exhibits high impedance when reverse biased due to the potential barrier formed by the depletion region, thereby possessing ideal diode rectification characteristics. This innovative device scheme and manufacturing method provides new possibilities for applications in the fields of microelectronics, nanophotonic electronics, etc., and is expected to promote the development and application of related technologies.

[0074] The above further describes the present application in conjunction with specific / preferred embodiments, and cannot be deemed to limit the specific implementation of the present application to these descriptions. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, they can make several substitutions or variations to the described embodiments, and these substitutions or variations shall be deemed to fall within the protection scope of the present application. In the description of the present application, the description of the terms "an embodiment", "some embodiments", "a preferred embodiment", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the case of no mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples. Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A diode device based on a single carbon nanotube structure, characterized by, A single carbon nanotube; a metal end formed by cutting one end of the carbon nanotube along the axial direction, having metallic property, and having no band gap in its energy band structure; a semiconductor end formed by the other end of the carbon nanotube, keeping the complete chirality, having semiconductor property, and having a band gap greater than 0 in its energy band structure; a Schottky junction formed at the contact interface between the metal end and the semiconductor end, forming a depletion region at the interface, and allowing current to flow from the metal end to the semiconductor end under forward bias condition, and preventing current from passing due to the potential barrier formed by the depletion region under reverse bias condition; electrodes assembled on the metal end and the semiconductor end. The carbon nanotube has chirality (n, m) with m = 0 or n - m ≠ 3q, wherein n and m are integers, q is an integer, and n > m.

2. The single carbon nanotube structure based diode device of claim 1, wherein, The energy band of the semiconductor end has a band gap of 0.1-2.0 eV.

3. The single carbon nanotube structure based diode device of claim 1, wherein, The method comprises the following steps:

4. A method of fabricating a single-walled carbon nanotube structure-based diode device according to any one of claims 1 to 3, characterized by, dispersing the carbon nanotube in a solvent; drop-casting or spray-casting the dispersed carbon nanotube solution on a clean substrate to form a uniform carbon nanotube film after drying; cutting one end of the carbon nanotube along the axial direction to form a metal end, and keeping the other end of the carbon nanotube as a complete nanotube structure to form a semiconductor end; a Schottky junction is formed at the contact interface between the metal end and the semiconductor end; assembling electrodes on the metal end and the semiconductor end. A single carbon nanotube having different conductive property regions; 5. A single carbon nanotube structure based p-n junction diode device, characterized in that, a p-type semiconductor end formed by one end of the carbon nanotube, doped with boron atoms to have p-type semiconductor property; an n-type semiconductor end formed by cutting the other end of the carbon nanotube along the axial direction, introducing additional dangling electrons, and having n-type semiconductor property; a p-n junction formed at the contact interface between the p-type semiconductor end and the n-type semiconductor end, forming a depletion region at the interface, and allowing current to flow from the n-type semiconductor end to the p-type semiconductor end under forward bias condition, and preventing current from passing due to the potential barrier formed by the depletion region under reverse bias condition; electrodes assembled on the p-type semiconductor end and the n-type semiconductor end. The carbon nanotube has chirality (n, m) with m = 0 or n - m ≠ 3q, wherein n and m are integers, q is an integer, and n > m. The method comprises the following steps:

6. The single carbon nanotube structure based p-n junction diode device according to claim 5, wherein dispersing the carbon nanotube in a solvent; 7. A method of fabricating a single carbon nanotube structure based p-n junction diode device as claimed in any one of claims 5 to 6, wherein, drop-casting or spray-casting the dispersed carbon nanotube solution on a clean substrate to form a uniform carbon nanotube film after drying; boron atom doping at one end of the carbon nanotube to form a p-type semiconductor end, and cutting the other end of the carbon nanotube along the axial direction to form an n-type semiconductor end; a p-n junction is formed at the contact interface between the p-type semiconductor end and the n-type semiconductor end; assembling electrodes on the p-type semiconductor end and the n-type semiconductor end. ​ ​ 8. The method for fabricating a pn junction diode device based on a single carbon nanotube structure as described in claim 7, characterized in that, The assembling the electrode at the p-type semiconductor end and the n-type semiconductor end specifically comprises: using electron beam lithography, exposing according to the designed electrode, forming a pattern in the exposed area after developing, forming the electrode through metal deposition and stripping photoresist; and performing heat treatment and annealing to ensure the contact between the electrode and the carbon nanotube.

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