Nanoscale vertical electrode array, multichannel nanowire electrode and preparation method thereof

Abstract

The application provides a nanometer vertical electrode array, a multi-channel nano array electrode and a preparation method of both. The preparation method of the nanometer vertical electrode array is based on a scanning electron microscope and / or a transmission electron microscope in which a nanometer operation robot is installed in a sample chamber, and a precursor metal material is directly written and deposited to form the nanometer vertical electrode array under a near-field and / or far-field electromagnetic field. The preparation method of the nanometer vertical electrode array based on an energy field control adopts the nanometer operation robot, replaces a traditional pick-and-place operation with a direct writing technology, greatly improves the operation speed of a nano structure or even a single atom, and obtains super-high machining precision, so that the speed and machining precision bottleneck of the nanometer robot operation is broken through.

Description

Technical Field

[0001] This invention relates to the field of nanoelectrode technology, specifically to a nanoscale vertical electrode array, a multi-channel nanoarray electrode, and methods for preparing both. Background Technology

[0002] Nanoelectrodes are electrodes with at least one dimension at the nanometer scale (1-100 nanometers). With the development of micro- and nano-manufacturing technology, microelectrodes, due to their advantages such as high current density, multiple recording points, small size, and minimal cell damage, are expected to be gradually applied to the detection of electrochemical, biological cells, and neural engineering systems.

[0003] Nanoscale vertical electrode arrays are crucial experimental tools for single-cell electrophysiological research. Existing patch clamps, limited by manufacturing processes, cannot be easily replicated using traditional methods after scaling down. Patch clamp probes based on atomic force microscopy typically only accommodate single pairs of electrodes. Applying multiple electrodes to single neurons and synapses allows for simultaneous recording of neuronal responses during electrical stimulation. It enables signal mapping between single neurons and multiple synapses, and decoding of neural signals between cells and between neurons and synapses. These are key general-purpose components for neuroscience research, brain-computer interface technology, and the control and feedback of intelligent prostheses based on peripheral nerve signals, with broad applications and market prospects in various fields such as public welfare and rehabilitation. In public welfare and rehabilitation, research on rehabilitation equipment for the disabled will promote harmonious social development and bring significant social and economic benefits.

[0004] In recent years, with the development of neuromorphic nanodevices, ion batteries, and memristors, nanorobot manipulators in transmission electron microscopy (TEM), as an extremely important and unique cutting-edge technological tool, have become a powerful tool for in-situ prototyping and characterization of ion-migrating devices. They provide important technical means and scientific basis for the development of new materials, artificial intelligence hardware, new energy devices, brain-computer interfaces, and quantum devices, including ion migration mechanisms, electrode and electrolyte selection, charge-discharge efficiency improvement, and failure mechanism analysis. Nanorobot manipulation within TEM has been successfully used for the manipulation, fabrication, characterization, and assembly of nanomaterials and structures, thus serving as an ideal platform for studying near-field ion behavior. In recent years, perhaps the most exciting breakthrough in TEM has been the application of spherical aberration (Cs) and chromatic aberration (Cc) correction in commercially available TEMs, which has significantly improved imaging resolution from the sub-nanometer level to the sub-angstrom level.

[0005] TEM offers sub-nanometer to subatomic imaging resolution (with aberration-corrected TEMs achieving resolutions as high as approximately 60-70 pm), fully real-time imaging capabilities independent of scanning, and no requirements on sample conductivity. Furthermore, TEMs are typically equipped with elemental-level material characterization devices, making them particularly suitable for high-precision nanomanipulation related to atomic / ionic structure and physical / chemical properties. However, the small size of the TEM cavity (the two main commercially available TEMs have cavity diameters of only about 10 mm and 15 mm) and the requirement for ultra-thin sample thicknesses (<100 nm) pose significant challenges to the development of nanorobot manipulation techniques for TEMs.

[0006] Electron beam focusing deposition technology developed gradually with the application of electron microscopy. It was initially noticed during the observation of samples in a vacuum environment, and later attributed to surface contamination caused by residual pump oil decomposing under electron beam irradiation. Focused electron beams generally refer to electron beams focused by electromagnetic lenses deflecting the electron trajectory in a high vacuum environment. Focused electron beams are widely used for high-resolution imaging in scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electron beam is accelerated by voltages ranging from tens to hundreds of kilovolts from a high vacuum (×10⁻⁶). -7 The electron beam, drawn from a chamber (Pa), is repeatedly focused by electromagnetic coils to form an extremely fine spot on the material surface. The size of the spot is typically between a few nanometers and tens of nanometers. The electron gun in a commercial scanning electron microscope has a high degree of integration and is mainly adjusted by factors such as the field emission electron gun, accelerating voltage, working distance, electron beam spot size, and aperture size.

[0007] Nanomanipulation robots mainly manipulate objects through the surface energy field of their end effectors. The short range of the surface energy field means that nanomanipulation robots can only directly grasp and place the manipulated objects to assemble and process electrodes. Each electrode needs to be prepared individually, which is inefficient, time-consuming, and cannot meet the needs of modern industries. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a nanoscale vertical electrode array, a multi-channel nanoarray electrode, and a method for preparing both, thereby improving the preparation rate and precision of nanoelectrodes.

[0009] To achieve the above objectives, the first aspect of the present invention provides a method for fabricating a nanoscale vertical electrode array based on energy field control, which is based on a scanning electron microscope and / or a transmission electron microscope with a nanomanipulation robot installed in the sample chamber, so as to directly deposit the precursor metal material under the electromagnetic fields of near field and / or far field to form the nanoscale vertical electrode array.

[0010] The nanomanipulation robot is equipped with multiple end effectors; during near-field direct writing, the end effectors provide visual servoing based on electron beam imaging from a transmission electron microscope or a scanning electron microscope; during far-field direct writing, the end effectors provide visual servoing based on electron beam imaging from a scanning electron microscope.

[0011] To address the shortcomings of existing nanomanipulation robots, the present invention employs a nanorobot equipped with a high-energy electromagnetic field-type end effector to fabricate a nanoscale vertical electrode array. This allows the precursor metal material to be ionized and emitted or migrated to the sample substrate under the control of a high-energy electromagnetic field. Combined with position servo control, a nanoscale vertical electrode array is formed, improving the fabrication precision of the electrodes. Furthermore, the electrode array fabrication method of this invention uses direct writing instead of assembly and can be equipped with multiple end effectors to achieve parallel processing at multiple locations, significantly improving the fabrication efficiency of the nanoelectrodes.

[0012] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, preferably, during near-field direct write deposition, the end effector is equipped with a nanoscale metal ion source, and the nanomanipulation robot adjusts the nanoscale metal ion source to the processing position on the sample end substrate via visual servoing. The nanoscale metal ion source is deposited onto the sample end substrate under the action of a near-field high-energy electromagnetic field to form the nanoscale vertical electrode array.

[0013] The near-field direct-write deposition method of this invention replaces the traditional far-field generator with a near-field ion and electron generator, generating a field strength at a voltage of several volts that would require tens of kilovolts in the far field, greatly improving ionization efficiency and reducing production costs. Simultaneously, the near-field ionization of this invention provides a universal method for metal atom ionization, overcoming the limitation of traditional focused ion beam (FIB) to only a few precursor materials such as gallium ions. Using metal particles as a nano-metal ion source to achieve 3D direct writing expands the quality and scale of 3D metal structure additive manufacturing to the atro-scale (10^6 kilovolts). -18 g) and nanoscale, can impact a small number of atoms or even a single atom; the ability of single ions to manipulate in the nanofield also brings new possibilities for local doping of nanostructures.

[0014] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, during near-field direct write deposition, preferably, the near-field electromagnetic field is formed by applying a bias voltage between the nanoscale metal ion source and the sample end substrate, and the near-field working voltage is the bias voltage, which is 1-50V, more preferably 10V.

[0015] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, during near-field direct writing deposition, preferably, the near-field working distance is the distance between the nanoscale metal ion source and the sample end substrate, wherein the near-field working distance is 1-30 nm, and more preferably 10 nm.

[0016] In the above-mentioned method for fabricating nanoscale vertical electrode arrays based on energy field control, during near-field direct writing deposition, preferably, the radius of curvature of the tip of the nanoscale metal ion source is <20nm, so as to achieve the concentration and convergence of the electric field.

[0017] For near-field direct write deposition, the energy field is determined by the working voltage and working distance between the nano-metal ion source and the electrode, as well as the morphology of the ion source tip. Changing these parameters can adjust the taper, tip curvature radius, tip atomic structure, and deposition rate of the direct write deposition electrode.

[0018] In the above-described method for fabricating a nanoscale vertical electrode array based on energy field control, during near-field direct-write deposition, preferably, the material of the nanoscale metal ion source is selected from silver nanowires, gold nanowires, or tungsten nanowires. The nanoscale metal ion source of this invention refers to a metal nanomaterial that can be ionized and supply metal ions to the outside under the influence of lasers, strong electric fields, electron beam irradiation, etc.

[0019] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, preferably, during far-field direct-write deposition, the nanomanipulation robot carries the deposition precursor material, and the end effector carries the sample end substrate. The nanomanipulation robot adjusts the position of the sample end substrate according to the visual servo of the imaging system of the scanning electron microscope, and works in conjunction with the electron source and electromagnetic lens system of the scanning electron microscope to focus the electron beam of the scanning electron microscope, which provides the far-field electromagnetic field, on the processing position of the sample end substrate, forming a local electric field. Under the action of the far-field electromagnetic field, the deposition precursor material is deposited to the electron beam focusing position, decomposes into metal ions during the deposition process, and is reduced to form the nanoscale vertical electrode array.

[0020] The present invention employs a far-field electromagnetic field preparation method. The nanorobot manipulator serves as a stage with sub-nanometer displacement resolution. Even when combined with a far-field particle beam or electron beam, it can precisely control the direct writing position of each vertical electrode through position servoing, and enhance its ability to model the 3D nanostructures of vertical electrodes (the tip taper, tip radius of curvature, and tip atomic structure of the electrode), thus achieving results that surpass the traditional electron beam induced deposition (EBID) and focused ion beam (FIB) methods.

[0021] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, during far-field direct writing deposition, preferably, the distance between the deposition precursor material and the sample end substrate is 0.2-3 cm, more preferably 1 cm.

[0022] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, during far-field direct writing deposition, preferably, the far-field electromagnetic field is formed by the electron beam system and electromagnetic lens system of a scanning electron microscope; the far-field working voltage is the electron beam accelerating voltage of the scanning electron microscope, and the far-field working voltage is 1-20kV; the far-field working current is the electron beam current of the scanning electron microscope, and the far-field working current is 10pA-50nA.

[0023] In the above-mentioned method for fabricating a nanoscale vertical electrode array based on energy field control, during far-field direct writing deposition, preferably, the far-field working distance is the distance between the sample end substrate and the electron beam pole piece, and the far-field working distance is 1-10 mm.

[0024] For far-field direct-write deposition, the energy field is determined by the working voltage, working current, and working distance of the electron beam in the scanning electron microscope system. Changing these parameters can adjust the taper, tip curvature radius, tip atomic structure, and deposition rate of the direct-write deposition electrode.

[0025] In the aforementioned method for fabricating nanoscale vertical electrode arrays based on energy field control, preferably, when near-field direct-write deposition and far-field direct-write deposition are combined, the fabrication method includes first fabricating nanoscale vertical electrodes using far-field direct-write deposition, and then using near-field direct-write deposition to controllably process the surface morphology and crystal structure of the fabricated electrodes, i.e., performing tip modification and shaping. When combined, the processing methods of near-field direct-write deposition and far-field direct-write deposition are consistent with those when used individually.

[0026] This invention enables the fabrication of more complex three-dimensional metal nanostructures through electrostatic migration, beam spot deflection, and servo control of the sample stage.

[0027] The second aspect of the present invention provides a method for fabricating a nanoscale vertical electrode array based on energy field control to obtain a nanoscale vertical electrode array.

[0028] In the above-mentioned nanoscale vertical electrode array, preferably, each vertical electrode includes an electrode body and an electrode tip, wherein the aspect ratio of the electrode body is >20, the electrode diameter is 20nm-10μm, the radius of curvature of the electrode tip is less than 5nm, and the diameter of the middle part of the vertical electrode is <50nm.

[0029] The metal electrode structure in this invention has superior toughness compared to silicon-based materials, and superior structural strength and conductivity compared to carbon-based electrode structures.

[0030] A fourth aspect of the present invention provides a multi-channel nanoarray electrode, comprising a three-dimensional electrode region, a terminal connection wire, and an external lead-out circuit connected in sequence; the three-dimensional electrode region includes an electrode wire, an electrode substrate, and the aforementioned nanoscale vertical electrode array, wherein one end of the electrode wire is connected to the nanoscale vertical electrode array through the electrode substrate, and the other end is connected to the terminal connection wire.

[0031] In the aforementioned multi-channel nanoarray electrode, preferably, the external lead-out circuit includes a lead-out electrode and a connection electrode, wherein the lead-out electrode is connected to the terminal connection wire through the connection electrode.

[0032] In the above-mentioned multi-channel nanoarray electrode, preferably, the vertical electrode array is uniformly arranged with an electrode spacing of 100-500 nm; the linewidth of the electrode wire is <100 nm; and the linewidth of the terminal connection wire is <100 nm.

[0033] The multi-channel nanoarray electrode of this invention acquires electrical signals through a nanoscale vertical electrode array and transmits these signals to a signal acquisition device via terminal connecting wires and external lead-out circuits, thereby achieving data collection and processing. For the uniformly arranged electrode array in a plane, the distance between each electrode is 100-500 nm. The linewidth of the terminal connecting wire is less than 100 nm, and the aspect ratio of the needle-shaped electrode's three-dimensional structure is greater than 20. The average electrode diameter is less than 100 nm, and the tip curvature radius is 5 nm.

[0034] A fourth aspect of the present invention provides a method for preparing the above-mentioned multichannel nanoarray electrode, comprising the following steps:

[0035] S1: External lead-out circuits are fabricated on the substrate using photolithography, electron beam exposure, or vapor deposition methods;

[0036] S2: Terminal connection wires, electrode wires and electrode substrates are fabricated on the substrate using photolithography, electron beam exposure or focused ion beam etching;

[0037] S3: Using the above-described method for fabricating a nanoscale vertical electrode array based on energy field control, a nanoscale vertical electrode array is fabricated on the electrode substrate to obtain the multi-channel nanoarray electrode.

[0038] The fabrication method of the multichannel nanoarray electrode of the present invention has a simple manufacturing process. On a pre-prepared silicon wafer substrate, the array can be customized according to the required structure and size of the microelectrode through direct writing technology.

[0039] In the fabrication method of the multi-channel nanoarray electrode of the present invention, the terminal connecting wire is produced by micro-nano manufacturing technology such as photolithography, electron beam exposure or focused ion beam etching, with a width of less than 100 nanometers. It is connected to the external lead circuit and to the electrode growth position (electrode substrate) on the substrate, and to the three-dimensional vertical electrode array. Pt and Au three-dimensional vertical electrodes are fabricated on the electrode substrate by electron beam induced deposition.

[0040] Furthermore, the multi-channel nanoarray electrode of this invention can also have its surface modified with amorphous carbon or other biocompatible materials. Due to carbon contamination in the microscope vacuum chamber, a certain amount of free carbon accumulates on the surface of the deposited three-dimensional nanoelectrode, forming a carbon shell outside the metal structure. The carbon composition and content in the electrode can be altered through processes such as plasma cleaning, annealing, and tempering.

[0041] The technical solution provided by this invention has the following beneficial effects:

[0042] (1) The method for fabricating a nanoscale vertical electrode array provided by the present invention uses a nanomanipulation robot and replaces the traditional pick-and-place operation with direct writing technology, which greatly improves the operation speed of nanostructures or even single atoms, thereby breaking through the speed bottleneck of nanorobot operation and improving the fabrication efficiency of nanoelectrodes; at the same time, the nanoelectrode fabrication method based on energy field control greatly improves the fabrication precision of the electrode (to the single atom level), and can more flexibly adjust the taper and height of the fabricated electrode according to the requirements, and has a strong electrode shaping capability.

[0043] (2) The method for fabricating nanoscale vertical electrode arrays based on energy field control of the present invention realizes the fabrication of ultra-fine electrode array structures with large aspect ratio (>20) vertical arrays (tip curvature radius <5nm, probe middle diameter <50nm), and the electrode spacing can be controlled to below 100nm; through TEM near-field in-situ research, the acquisition of sub-10nm tips is attributed to self-focusing.

[0044] (3) The method for fabricating a nanoscale vertical electrode array based on energy field control of the present invention can be used for small-batch manufacturing of 3D electrodes. The portion of the electrode led out on the substrate that is less than 1 μm can be customized by FIB, which can reduce the difficulty of photolithography and electron beam exposure processing technology, improve the yield and modularity, increase the processing speed, and quickly process complex electrode structures. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the near-field direct-write fabrication principle of the nanoscale vertical electrode array in Example 1.

[0046] Figure 2The diagram below shows the near-field ion generation and emission process in Example 1. (a) is a schematic diagram of the near-field ion gun, (b) shows ions being ejected from the gun towards the target, and the near-field direct-write metal nanoelectrode, (c) shows the self-focusing and cascade emission of ions, (d) shows the time series of ion emission layer by layer, and (e) shows the time series of near-single-ion emission.

[0047] Figure 3 This refers to the ion gun position control and target-end ion self-assembly in near-field direct writing in Example 1.

[0048] Figure 4 This is a schematic diagram of the far-field direct-write fabrication principle of the nanoscale vertical electrode array in Example 2;

[0049] Figure 5 The image shows a transmission electron microscope (TEM) image of a single nano-vertical electrode from Example 2, where (a) is the overall view of the electrode, (b) is the middle part of the electrode, (c) is the tip of the electrode, and (d) is the root of the electrode.

[0050] Figure 6 The images are scanning micrographs of the 50nm tip deposited in Example 2 at write field sizes of 5K, 10K, 150K and 200K.

[0051] Figure 7 This is a schematic diagram of the structure of the multichannel nanoarray electrode in Example 3;

[0052] Figure 8 These are scanning electron microscope images of the terminal connection wire, electrode wire, and electrode substrate in Example 3;

[0053] Figure 9 This refers to the 4×4 high aspect ratio three-dimensional vertical electrode array in Example 3;

[0054] Figure 10A The wafer substrate pretreated in Example 3;

[0055] Figure 10B The wafer substrate for which external lead-out circuits and terminal connection wires were fabricated in Example 3;

[0056] Figure 10C The wafer substrate for which electrode wires and a three-dimensional vertical electrode substrate were fabricated in Example 3;

[0057] Figure 10D The wafer substrate for which the vertical electrode array was fabricated in Example 3 is shown. Detailed Implementation

[0058] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0059] Example 1

[0060] This embodiment provides a method for fabricating a nanoscale vertical electrode array based on energy field control, which employs near-field direct-write deposition, such as... Figure 1 As shown, this preparation method is based on a transmission electron microscope with a nanomanipulation robot installed in the sample chamber. The nanomanipulation robot is equipped with multiple end effectors, which provide visual servoing based on the imaging of the transmission electron microscope. The specific preparation method is as follows:

[0061] The target area to be deposited on the sample substrate is imaged and focused under a transmission electron microscope;

[0062] The end effector is equipped with silver nanowires as a nano-metal ion source, and the end effector is controlled to approach the target area to be deposited under the visual servo of a transmission electron microscope.

[0063] The distance between the nano-metal ion source and the target area to be deposited was adjusted to 10 nm. A 10 V positive bias voltage was applied to the ion source end, and the target area was grounded to form a 10 V operating voltage. This allowed the nano-metal ion source to deposit onto the sample substrate under the influence of a near-field electromagnetic field. The radius of curvature of the nano-metal ion source tip was less than 20 nm. Figure 2 As shown in (b) in the image;

[0064] After a 735s deposition process, an ultrafine nano-vertical electrode with a length of 23nm and a tip curvature radius of less than 10nm was deposited at the desired processing location. The resulting silver electrode has a face-centered cubic crystal structure. The deposition rate of this atomically controlled deposition process was 1.87nm / min. The resulting vertical electrode is shown in the figure. Figure 2 As shown in (b), the deposition rate can be increased to 500 nm / min by increasing the working voltage between the ion source and the substrate. The aspect ratio of the grown electrode is determined by the deposition time and the selection of the ion source.

[0065] Repeating the above deposition steps can achieve the growth of micrometer-long electrodes on the original substrate. By adjusting the relative position of the nano-metal ion source and the sample end substrate spacing, a nanoscale vertical electrode array can be obtained.

[0066] Figure 2This diagram illustrates the near-field ion generation and emission process. As shown in (a), with a 10V bias voltage applied to the probe and sample, ions are drawn from the silver particles held at the anode and directed towards the target, as shown in (b). (c) shows that the first ions to reach the target become pointed protrusions protruding from the cathode, causing electrons to concentrate at their tips, thus focusing subsequent ions. As the ions are consumed, the initial emission protrusion at the nano-metal ion source shifts laterally from the point of strongest electrostatic field to the point of strongest electrostatic field, resulting in a continuous emission phenomenon, or cascade emission. (d) shows the time series of layer-by-layer ion emission, and (e) shows a high-resolution TEM image of Ag ion epitaxial deposition at a specified location on the target. Excitingly, only a few ions are deposited at a time, and the entire event sequence demonstrates the ability to model the electric field releasing a small number of ions within 47 seconds according to the epitaxial deposition process with ultra-high resolution. A comparison of the edge regions reveals the boundary layer of the target in its initial state and the newly deposited atoms. As the experiment shows, changes in the target tip topology dynamically affect the final position of the ions. By effectively utilizing this self-organizing ability, atomic-level positioning and shaping will become possible.

[0067] Figure 3 The changes in the target structure as the nanometal ion source is moved are shown. (a)-(e) show the deposition on Pt@C: (a) the initial state of the Pt@C surface; (b) the deposited surface after 400 s, showing a clear and dense Ag particle film; (c) is a partial TEM image of the deposited film; the crystal structures corresponding to regions #1 and #2 in (c) are shown in (d) and (e); (f) is the initial state of the amorphous silicon surface; newly grown seeds are marked with dashed circles in (i); the position of the silver ion source has been shifted a few nanometers to the right; in (j), particle #1 has grown larger, and particle #5 has appeared; as shown in (k), the ions deposited on silicon self-organize into a rhombic octahedral appearance.

[0068] Example 2

[0069] This embodiment provides a method for fabricating a nanoscale vertical electrode array based on energy field control, which employs far-field direct-write deposition, such as... Figure 4 As shown, this preparation method is based on a scanning electron microscope with a nanomanipulation robot installed in the sample chamber. The nanomanipulation robot is equipped with multiple end effectors, which provide visual servoing based on electron beam imaging from the scanning electron microscope. The specific preparation method is as follows:

[0070] The target area to be deposited on the sample substrate is imaged and focused under a scanning electron microscope;

[0071] A nanomanipulation robot is equipped with a Pt deposition precursor material, and the end effector is equipped with a sample end substrate. The nanomanipulation robot servo adjusts the position of the sample end substrate.

[0072] The electron gun and electromagnetic lens system of the scanning electron microscope form a far-field electromagnetic field. The combined action of the nanomanipulation robot, the electron source of the scanning electron microscope, and the electromagnetic lens system enables the electron beam of the scanning electron microscope, which provides the far-field electromagnetic field, to be focused on the processing position of the sample end substrate.

[0073] The distance between the deposition precursor and the sample end substrate was controlled at 1 cm, the electron beam accelerating voltage was adjusted to 20 kV, the electron beam current to 50 pA, the distance between the sample end substrate and the electron beam pole piece (working distance) was 4 mm, and the irradiation electron dose was 1.1 × 10⁻⁶. - 5 pC / μm 2 At that time, the smallest electron beam spot is obtained, and the precursor material is deposited to the electron beam focusing position under the action of the far-field electromagnetic field;

[0074] After 30 seconds of direct-write deposition, the precursor material decomposes into metal ions and forms a single nano-vertical electrode at the electron beam focusing position. The nano-vertical electrode has a length of 1657 nm, an average diameter of about 72 nm, an aspect ratio of 23, a tip curvature radius of 7.1 nm, and a deposition rate of 3314 nm / min.

[0075] The single nanoscale vertical electrode prepared in this embodiment was characterized using transmission electron microscopy, and the results are shown in the figure. Figure 5 and Figure 6 . Figure 5 The transmission electron microscope (TEM) image shows that the three-dimensional electrode is composed of amorphous Pt clusters and free C clusters, with Pt accounting for approximately 75% of the mass. Here, the sub-10 nm tip radius is closely related to the self-focusing phenomenon, which is also an important factor in achieving a large aspect ratio. Figure 6 The images show scanned images of a 50 nm tip after deposition at magnifications of 5K, 10K, 150K, and 200K. The results indicate that the taper of the deposited structure can be effectively controlled by adjusting the size of the write field.

[0076] Example 3

[0077] This embodiment provides a multi-channel nanoarray electrode, such as Figure 7As shown, the multi-channel nanoarray electrode includes a three-dimensional electrode region, a terminal connection wire, and an external lead-out circuit connected in sequence. The three-dimensional electrode region includes an electrode wire, an electrode substrate, and the nanoscale vertical electrode array prepared in Example 2. One end of the electrode wire is connected to the nanoscale vertical electrode array through the electrode substrate, and the other end is connected to the terminal connection wire. The external lead-out circuit includes an lead-out electrode and a connection electrode. The lead-out electrode is connected to the terminal connection wire through the connection electrode.

[0078] In the multi-channel nanoarray electrode of this embodiment, the vertical electrode array is uniformly arranged with an electrode spacing of 100-500 nm; the linewidth of the electrode wire is <100 nm; and the linewidth of the terminal connection wire is <100 nm.

[0079] The fabrication method of the multichannel nanoarray electrode in this embodiment includes the following steps:

[0080] External lead circuits were fabricated on a silicon substrate (3mm◇4mm◇0.5mm) using photolithography and electron beam lithography processes.

[0081] Terminal interconnect wires, electrode wires, and electrode substrates (4×4 array) were fabricated on a silicon substrate by focused ion beam etching. The electrode substrate spacing was set to 500 nm, the electrode wire width was approximately 50 nm, and the electrode wire material was gold. Figure 8 Scanning electron microscope images of the electrode wires and electrode substrate;

[0082] Using the preparation method of Example 2, a nanoscale vertical electrode array was fabricated on top of an electrode substrate to obtain the multi-channel nanoarray electrode; wherein, Figure 9 It is a 4×4 three-dimensional vertical electrode array with a large aspect ratio.

[0083] The fabrication method of the multichannel nanoarray electrode in this embodiment is as follows: Figures 10A-10D As shown, Figure 10A For the pre-treated wafer substrate, Figure 10B For fabricating wafer substrates with external lead-out circuits and terminal connection wires, Figure 10C For the fabrication of a wafer substrate with electrode wires and a three-dimensional vertical electrode substrate, Figure 10D For a wafer substrate with a vertical electrode array fabricated.

[0084] Example 4

[0085] This embodiment provides an electrode fabrication method that combines far-field and near-field fabrication methods based on an energy field. This method mainly includes the fabrication process of a high aspect ratio nanoelectrode using a scanning electron microscope based on a nanomanipulation robot, a far-field electromagnetic field, and a deposition precursor material; and the modification process of the near-field fabricated nanoelectrode using a nanomanipulation robot, a near-field electromagnetic field, and a metal ion source. The main structure of the electrode (a needle-like structure with a micrometer length) is fabricated using the higher fabrication rate of the far-field method, while the tip of the fabricated electrode body is modified with atomic-level processing precision using the near-field method to achieve an ultra-small (sub-nanometer) tip.

[0086] First, a silicon substrate is selected based on the application scenario of the nanoelectrode array. Typically, in this embodiment, the silicon substrate size is 3mm × 4mm × 0.5mm. The substrate electrode is first fabricated on the silicon substrate using processes such as ultraviolet lithography, evaporation deposition, and focused ion beam etching. The basic parameters and fabrication methods are consistent with those in Example 3.

[0087] First, the main structure of the electrode is fabricated using a far-field method. The basic steps and parameters are consistent with those described in Example 2. A vertical electrode structure with a micrometer-scale length and a curvature radius of tens of nanometers is fabricated on the electrode substrate. The main body of the vertical electrode structure has a diameter of less than 100 nm and an aspect ratio of more than 20.

[0088] After fabricating the main body of the vertical electrode structure using a far-field method, a nano-manipulation robot carrying a nano-metal ion source is used in a scanning electron microscope (SEM). Electron beam imaging from the SEM provides visual servoing for the nanorobot's movement, allowing the distance between the nano-metal ion source and the proximal end of the nano-electrode structure obtained in the previous fabrication step to be adjusted to 5 nm. The nano-electrode is partially grounded, and a 10V operating voltage is applied to the nano-metal ion source. Metal ions are emitted from the source surface and deposited at the tip of the nano-electrode, forming a modified electrode tip. By dynamically controlling the operating distance (5-20 nm), the precision of the modified electrode tip can be controlled at the single-atom level. Figure 2 Part (e). Visual servoing is provided by scanning electron microscopy imaging, which moves a nanomanipulation robot equipped with a nano-metal ion source to modify the previously prepared multiple metal electrode structures.

[0089] Thus, by combining the far and near fields, a vertical metal nanostructure array with a large aspect ratio (>20), micrometer-scale length, ultra-small diameter (>100nm), and single-atom-scale tip was achieved.

Claims

1. A method for fabricating a nanoscale vertical electrode array based on energy field control, wherein, The method for fabricating the nanoscale vertical electrode array based on energy field control is based on a scanning electron microscope and / or a transmission electron microscope with a nanomanipulation robot installed in the sample chamber. The precursor metal material is directly written and deposited under a near-field electromagnetic field to form the nanoscale vertical electrode array, or the precursor metal material is directly written and deposited under near-field and far-field electromagnetic fields to form the nanoscale vertical electrode array. The nanomanipulation robot is equipped with multiple end effectors; during near-field direct writing, the end effectors provide visual servoing based on electron beam imaging from a transmission electron microscope or a scanning electron microscope; during far-field direct writing, the end effectors provide visual servoing based on electron beam imaging from a scanning electron microscope. During near-field direct write deposition, the end effector is equipped with a nano-metal ion source, and the nanomanipulation robot adjusts the nano-metal ion source to the processing position on the sample end substrate via visual servoing. The nano-metal ion source is deposited onto the sample end substrate under the action of a near-field high-energy electromagnetic field to form the nanoscale vertical electrode array.

2. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 1, wherein, The near-field electromagnetic field is formed by applying a bias voltage between the nano-metal ion source and the sample end substrate, and the near-field operating voltage is the bias voltage, which is 1-50V.

3. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 2, wherein, The near-field operating voltage is 10V.

4. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 1, wherein, The near-field working distance is the distance between the nano-metal ion source and the sample end substrate, and the near-field working distance is 1-30nm.

5. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 4, wherein, The near-field working distance is 10 nm.

6. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 1, wherein, The tip curvature radius of the nano-metal ion source is <20 nm.

7. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 1, wherein, The material of the nano-metal ion source is selected from silver nanowires, gold nanowires, or tungsten nanowires.

8. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 1, wherein, During far-field direct-write deposition, the nanomanipulation robot carries the deposition precursor material, and the end effector carries the sample substrate. The nanomanipulation robot adjusts the position of the sample substrate according to the visual servo of the imaging system of the scanning electron microscope, and works in conjunction with the electron source and electromagnetic lens system of the scanning electron microscope to focus the electron beam of the scanning electron microscope, which provides the far-field electromagnetic field, on the processing position of the sample substrate, forming a local electric field. Under the action of the far-field electromagnetic field, the deposition precursor material is deposited to the electron beam focusing position, decomposes into metal ions during the deposition process, and is reduced to form the nanoscale vertical electrode array.

9. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 8, wherein, The distance between the deposition precursor and the sample substrate is 0.2-3 cm.

10. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 9, wherein, The distance between the deposition precursor and the sample substrate is 1 cm.

11. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 8, wherein, The far-field electromagnetic field is formed by the electron beam system and electromagnetic lens system of the scanning electron microscope; the far-field operating voltage is the electron beam accelerating voltage of the scanning electron microscope, and the far-field operating voltage is 1-20kV; the far-field operating current is the electron beam current of the scanning electron microscope, and the far-field operating current is 10pA-50nA.

12. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 8, wherein, The far-field working distance is the distance between the sample end substrate and the electron beam pole piece, and the far-field working distance is 1-10mm.

13. The method for fabricating a nanoscale vertical electrode array based on energy field control according to claim 1, wherein, When near-field direct-write deposition and far-field direct-write deposition are combined, the preparation method includes first fabricating a nano-vertical electrode using far-field direct-write deposition, and then controlling the surface morphology and crystal structure of the prepared electrode using near-field direct-write deposition.

14. A nanoscale vertical electrode array obtained by the fabrication method of the nanoscale vertical electrode array based on energy field control as described in any one of claims 1-13.

15. The nanoscale vertical electrode array according to claim 14, wherein, Each vertical electrode includes an electrode body and an electrode tip. The aspect ratio of the electrode body is >20, the electrode diameter is 20nm-10μm, the radius of curvature of the electrode tip is less than 5nm, and the diameter of the middle part of the vertical electrode is <50nm.

16. A multi-channel nanoarray electrode, comprising a three-dimensional electrode region, a terminal connection wire, and an external lead-out circuit connected in sequence; the three-dimensional electrode region includes an electrode wire, an electrode substrate, and a nanoscale vertical electrode array as described in claim 14 or 15, wherein one end of the electrode wire is connected to the nanoscale vertical electrode array through the electrode substrate, and the other end is connected to the terminal connection wire.

17. The multichannel nanoarray electrode according to claim 16, wherein, The external lead-out circuit includes lead-out electrodes and connection electrodes, and the lead-out electrodes are connected to the terminal connection wires through the connection electrodes.

18. The multichannel nanoarray electrode according to claim 16, wherein, The vertical electrode array is uniformly arranged with an electrode spacing of 100-500 nm; the linewidth of the electrode wire is <100 nm; and the linewidth of the terminal connection wire is <100 nm.

19. A method for fabricating a multichannel nanoarray electrode according to any one of claims 16-18, comprising the following steps: S1: External lead-out circuits are fabricated on the substrate using photolithography, electron beam exposure, or vapor deposition methods; S2: Terminal connection wires, electrode wires and electrode substrates are fabricated on the substrate using photolithography, electron beam exposure or focused ion beam etching; S3: A nanoscale vertical electrode array is fabricated on the electrode substrate using the fabrication method of the energy field-controlled nanoscale vertical electrode array according to any one of claims 1-13, thereby obtaining the multi-channel nanoarray electrode.

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