Preparation method and deposition device of nanomaterial

Abstract

This invention provides a method and deposition apparatus for preparing nanomaterials, comprising the following steps: providing a substrate; forming a first electrode and an insulating layer covering the first electrode on the substrate; forming a second electrode and a third electrode on the insulating layer, wherein the first electrode and the second electrode overlap on the projection of the substrate, but the first electrode and the third electrode do not overlap, and the first electrode, the second electrode, and the insulating layer between them constitute a first capacitor; providing a deposition source located at least between the second electrode and the third electrode; applying an alternating current voltage to the third electrode; and forming nanomaterials between the second electrode and the third electrode under dielectrophoresis. In this invention, the voltage between the second electrode and the third electrode is divided by the first capacitor to achieve self-termination of deposition, thereby precisely controlling the amount of nanomaterials deposited; furthermore, by adjusting whether the first electrode in different regions is grounded through a wire and the frequency of the alternating current voltage, precise control of different locations and quantities of nanomaterials can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of nanotechnology and relates to a method for preparing nanomaterials and a deposition apparatus. Background Technology

[0002] In existing technologies, when forming nanomaterials using dielectrophoresis, the deposition density is controlled by adjusting the concentration of the nanomaterial dispersion and regulating the deposition time. The principle is that the quantity of nanomaterials varies in dispersions of different concentrations, resulting in different deposition times. Controlling the concentration of the dispersion and the deposition time achieves quantity control. However, the distribution of nanomaterials in the dispersion is random, and methods relying solely on deposition time control are inherently random and difficult to control precisely.

[0003] Therefore, how to provide a method for preparing nanomaterials and a deposition device to achieve self-stopping deposition and thus achieve precise quantity control of nanomaterials has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for preparing nanomaterials and a deposition apparatus to solve the problems in the prior art where the deposition of nanomaterials cannot achieve self-termination and the deposition quantity cannot be precisely controlled.

[0005] To achieve the above and other related objectives, the present invention provides a method for preparing nanomaterials, comprising the following steps:

[0006] A substrate is provided, and a first electrode is formed on the substrate;

[0007] An insulating layer covering the first electrode is formed on the substrate;

[0008] A second electrode and a third electrode are formed on the insulating layer. On the projection of the substrate, the first electrode and the second electrode overlap, and the first electrode and the third electrode do not overlap. The first electrode, the second electrode, and the insulating layer between the first electrode and the second electrode constitute a first capacitor.

[0009] A deposition source is provided, the deposition source being at least located between the second electrode and the third electrode. The second electrode, the third electrode, and the deposition source between the second electrode and the third electrode constitute a second capacitor. An AC voltage is applied to the third electrode, and nanomaterials are formed between the second electrode and the third electrode under dielectrophoresis. After the nanomaterials are formed, the resistance between the second electrode and the third electrode changes, while the resistance between the first electrode and the second electrode does not change. The first capacitor divides the voltage of the second capacitor.

[0010] Optionally, the first capacitor and the second capacitor constitute a deposition combination, wherein a plurality of the deposition combinations are formed on the substrate.

[0011] Optionally, in the deposition assembly at the preset location, the first electrode is grounded via a wire, or the first electrode is not grounded via a conductive path.

[0012] Optionally, in the deposition combinations at different locations, the frequency of the AC voltage is equal; or the frequency of the AC voltage is unequal.

[0013] Optionally, the nanomaterial is a semiconductor material, and before forming the insulating layer, the step of forming a fourth electrode on the substrate is further included, the insulating layer covering the fourth electrode, and the projection of the fourth electrode on the substrate connecting / crossing the projections of the second electrode and the third electrode on the substrate.

[0014] The present invention also provides a nanomaterial deposition apparatus, comprising:

[0015] Substrate;

[0016] The first electrode is located on the substrate;

[0017] An insulating layer is located on the substrate and covers the first electrode;

[0018] The second electrode is located on the insulating layer;

[0019] The third electrode is located on the insulating layer. On the projection of the substrate, the first electrode and the second electrode overlap, but the first electrode and the third electrode do not overlap.

[0020] The first electrode, the second electrode, and the insulating layer between the first electrode and the second electrode constitute a first capacitor. When an AC voltage is applied to the third electrode, the first capacitor divides the voltage between the second electrode and the third electrode.

[0021] Optionally, the first electrode, the second electrode, and the third electrode constitute a deposition assembly, wherein a plurality of the deposition assemblies are provided on the substrate.

[0022] Optionally, in the deposition assembly at the preset location, the first electrode is grounded via a wire, or the first electrode is not grounded via a wire.

[0023] Optionally, in the deposition combinations at different locations, the frequency of the AC voltage is the same; or the frequency of the AC voltage is not the same.

[0024] Optionally, it further includes a fourth electrode located on the substrate, the insulating layer covering the fourth electrode, and the projection of the fourth electrode on the substrate connecting / across the projections of the second electrode and the third electrode on the substrate.

[0025] As described above, in the nanomaterial preparation method and deposition apparatus of the present invention, the voltage between the second electrode and the third electrode is divided by the first capacitor to achieve self-termination of nanomaterial deposition, so as to precisely control the amount of nanomaterial deposited; and, by adjusting whether the first electrode in different regions is grounded through a wire and the AC voltage frequency, precise control of nanomaterials in different positions and in different quantities can be achieved, so as to achieve array deposition of nanomaterials with controllable quantity. Attached Figure Description

[0026] Figure 1 The diagram shown is a process flow chart of the preparation method of nanomaterials in Embodiment 1 of the present invention.

[0027] Figure 2 The diagram shows a substrate provided in Embodiment 1 of the present invention, on which a first electrode is formed.

[0028] Figure 3 This is a schematic diagram showing the formation of an insulating layer covering the first electrode on a substrate in Embodiment 1 of the present invention.

[0029] Figure 4 This is a schematic diagram showing the formation of a second electrode and a third electrode on an insulating layer in Embodiment 1 of the present invention.

[0030] Figure 5 The diagram shown illustrates the formation of a deposition source on an insulating layer in Embodiment 1 of the present invention.

[0031] Figure 6 This diagram illustrates the formation of nanomaterials between the second and third electrodes in Embodiment 1 of the present invention.

[0032] Figure 7 The diagram shows the voltage change between the second and third electrodes before and after deposition in Embodiment 1 of the present invention.

[0033] Figure 8 The image shown is an electron microscope image of a single nanomaterial formed by grounding the first electrode through a wire in Embodiment 1 of the present invention.

[0034] Figure 9 The image shown is an electron microscope image of multiple nanomaterials formed by the first electrode not being grounded through a wire in Embodiment 1 of the present invention.

[0035] Figure 10 The image shown is an electron microscope image of a low-density nanomaterial formed by applying a low-frequency high-frequency AC voltage to the first electrode in Embodiment 1 of the present invention while it is grounded by a wire.

[0036] Figure 11 The image shown is an electron microscope image of high-density nanomaterials formed by applying a high-frequency AC voltage to the first electrode in Embodiment 1 of the present invention while it is grounded by a wire.

[0037] Figure 12 This is a schematic diagram showing multiple deposition combinations formed on a substrate in Embodiment 1 of the present invention.

[0038] Figure 13 The diagram shown is a schematic diagram of the separation setup of multiple deposition combinations in Embodiment 1 of the present invention.

[0039] Figure 14 The diagram shows a first electrode and a fourth electrode formed on a substrate in Embodiment 2 of the present invention.

[0040] Figure 15 The diagram shows an insulating layer formed on a substrate covering the first electrode and the fourth electrode in Embodiment 2 of the present invention.

[0041] Figure 16 This is a schematic diagram showing the formation of a second electrode and a third electrode on an insulating layer in Embodiment 2 of the present invention.

[0042] Figure 17 This is a schematic diagram of forming a deposition source on an insulating layer in Embodiment 2 of the present invention.

[0043] Figure 18 This is a schematic diagram showing the formation of nanomaterials between the second and third electrodes in Embodiment 2 of the present invention.

[0044] Figure 19 This is a schematic diagram showing the formation of multiple depositional combinations on the deposition surface in Embodiment 2 of the present invention.

[0045] Component designation explanation

[0046] 1 Substrate

[0047] 2 First electrode

[0048] 3 Insulation layer

[0049] 4 Second electrode

[0050] 5 Third electrode

[0051] 6. Sediment source

[0052] 7 nanomaterials

[0053] 8 First sedimentary assemblage

[0054] 9 Second sedimentary assemblage

[0055] 10 Third sedimentary assemblage

[0056] 11. Fourth electrode

[0057] Steps S1 to S4 Detailed Implementation

[0058] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0059] Please see Figures 1 to 19 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0060] Example 1

[0061] This embodiment provides a method for preparing nanomaterials, used for depositing low-resistivity nanomaterials. Please refer to [link to relevant documentation]. Figure 1 This includes the following steps:

[0062] S1: Provide a substrate, and form a first electrode on the substrate;

[0063] S2: An insulating layer covering the first electrode is formed on the substrate;

[0064] S3: A second electrode and a third electrode are formed on the insulating layer. On the projection of the substrate, the first electrode and the second electrode overlap, while the second electrode and the third electrode do not overlap. The first electrode, the second electrode, and the insulating layer between the first electrode and the second electrode constitute a first capacitor.

[0065] S4: Provide a deposition source, the deposition source being at least located between the second electrode and the third electrode, the second electrode, the third electrode, and the deposition source between the second electrode and the third electrode constituting a second capacitor, applying an AC voltage to the third electrode, and forming nanomaterials between the second electrode and the third electrode under dielectrophoresis, wherein, after the formation of the nanomaterials, the resistance between the second electrode and the third electrode changes, while the resistance between the first electrode and the second electrode does not change, and the first capacitor divides the voltage of the second capacitor.

[0066] The preparation method of the nanomaterials in this embodiment will be described in detail below with reference to the specific accompanying drawings.

[0067] First, please refer to Figure 2 Step S1: Provide a substrate 1 and form a first electrode 2 on the substrate 1.

[0068] As an example, the substrate 1 is an insulating substrate, or the substrate 1 is a conductive substrate with an insulating film on its surface, including but not limited to intrinsic silicon, flexible polymer, doped silicon with a silicon dioxide insulating film on its surface, etc., and the surface of the substrate 1 is smooth and flat.

[0069] As an example, the substrate 1 is cleaned before the first electrode 2 is formed.

[0070] Specifically, in this embodiment, the substrate 1 is a polished quartz substrate with dimensions of 1cm×1cm×500μm. The substrate 1 is ultrasonically cleaned in acetone, isopropanol and alcohol for 10 minutes in sequence, and then dried.

[0071] As an example, the material of the first electrode 2 includes, but is not limited to, conductive metals such as gold and copper, and one or more conductive films such as indium tin oxide and graphene.

[0072] Specifically, in this embodiment, a 5nm thick Cr metal layer and a 40nm thick Au metal layer are stacked from bottom to top on the substrate 1. Then, the shape and position of the first electrode are defined by photolithography or electron beam direct writing. Then, the Cr metal layer and Au metal layer are etched by ICP etching to form the first electrode 2. Since the Au metal layer has low adhesion on the quartz substrate, the Cr metal layer is used as an adhesion layer to increase the adhesion.

[0073] As an example, the method for forming the conductive material layer of the first electrode 2 includes, but is not limited to, one or more of the following methods: MOCVD, ALD, sputtering, evaporation, etc.

[0074] Next, please refer to Figure 3 Step S2: An insulating layer 3 covering the first electrode 2 is formed on the substrate 1.

[0075] As an example, the material of the insulating layer 3 includes, but is not limited to, one or more of silicon oxide, aluminum oxide, and hafnium oxide, and the method of forming the insulating layer 3 includes, but is not limited to, one or more of PECVD, ALD, sputtering, and vapor deposition.

[0076] Specifically, in this embodiment, the insulating layer 3 is made of silicon oxide and is formed by PECVD. The thickness of the insulating layer 3 is 1 μm.

[0077] Next, please refer to Figure 4 Step S3 is executed: a second electrode 4 and a third electrode 5 are formed on the insulating layer 3. On the projection of the substrate 1, the first electrode 2 and the second electrode 4 overlap, and the first electrode 2 and the third electrode 5 do not overlap. The first electrode 2, the second electrode 4, and the insulating layer 3 between the first electrode 2 and the second electrode 4 constitute a first capacitor.

[0078] As an example, the materials of the second electrode 4 and the third electrode 5 include, but are not limited to, conductive metals such as gold and copper, and conductive films such as indium tin oxide and graphene.

[0079] Specifically, in this embodiment, a 5nm thick Cr metal layer and a 40nm thick Au metal layer are stacked from bottom to top on the insulating layer 3. Then, the shape and position of the second electrode and the third electrode are defined by photolithography or electron beam direct writing. Then, the Cr metal layer and the Au metal layer are etched by ICP etching to form the second electrode 4 and the third electrode 5. Since the Au metal layer has low adhesion on the insulating layer 3, the Cr metal layer is used as an adhesion layer to increase the adhesion.

[0080] As an example, the methods for forming the conductive material layers of the second electrode 4 and the third electrode 5 include, but are not limited to, one or more of the following methods: MOCVD, ALD, sputtering, evaporation, etc.

[0081] Next, please refer to Figure 5 and Figure 6Step S4 is executed: a deposition source 6 is provided, the deposition source 6 being located at least between the second electrode 4 and the third electrode 5. The second electrode 4, the third electrode 5, and the deposition source 6 between the second electrode 4 and the third electrode 5 constitute a second capacitor. An AC voltage is applied to the third electrode 5, and nanomaterial 7 is formed between the second electrode 4 and the third electrode 5 under dielectrophoresis. After the nanomaterial 7 is formed, the resistance between the second electrode 4 and the third electrode 5 changes, while the resistance between the first electrode 2 and the second electrode 4 does not change. The first capacitor divides the voltage of the second capacitor.

[0082] As an example, the first electrode 2, the second electrode 4, and the insulating layer 3 between the first electrode 2 and the second electrode 4 constitute the first capacitor, and the second electrode 4, the third electrode 5, and the deposition source 6 between the second electrode 4 and the third electrode 5 constitute the second capacitor. That is, the second electrode 4 is the common electrode of the first capacitor and the second capacitor. When a high-frequency AC voltage is applied to the third electrode 5, the first electrode 2 serves as the ground terminal of the AC voltage, and the first capacitor and the second capacitor are connected in series.

[0083] As an example, the first capacitor acts as a pairing capacitor and the second capacitor acts as a trapping capacitor. When a high-frequency AC voltage is applied, the nanomaterial 7 is formed between the second electrode 4 and the third electrode 5 under the action of dielectrophoresis.

[0084] As an example, in this embodiment, the nanomaterial 7 is a low-resistivity material. After the nanomaterial 7 is formed between the second electrode 4 and the third electrode 5, the resistance between the second electrode 4 and the third electrode 5 changes. Since the first electrode 2 and the second electrode 4 are arranged in a vertical direction and isolated by the insulating layer 3, the deposition of the nanomaterial 7 between the first electrode 2 and the second electrode 4 is avoided. The nanomaterial 7 is only deposited between the second electrode 4 and the third electrode 5. The deposition of the nanomaterial 7 will not affect the resistance between the first electrode 2 and the second electrode 4, that is, the first capacitance will not change due to the deposition of the nanomaterial 7. After the nanomaterial 7 is deposited, the second electrode 4 and the third electrode 5 are connected. Due to the voltage division effect of the first capacitance, the voltage between the second electrode 4 and the third electrode 5 drops, hindering the subsequent deposition of nanomaterials and achieving self-termination of deposition.

[0085] As an example, in this embodiment, the deposition source 6 is a nanomaterial dispersion. In other examples, the deposition source 7 can also be a nanomaterial source suspended in a gaseous environment or a nanomaterial source suspended in a gel. The nanomaterial 7 includes, but is not limited to, nanoparticles, nanowires, nanotubes, nanosheets, etc. Specifically, in this embodiment, the deposition source 6 is a xylene dispersion of carbon nanotubes, and the formed nanomaterial 7 is a nanotube.

[0086] As an example, after forming the nanomaterial 7, the process further includes removing the residual deposition source 6 and disconnecting the AC voltage. Specifically, in this embodiment, xylene and acetone are used for cleaning to remove the residual deposition source 6.

[0087] As an example, by controlling whether the first electrode 2 is grounded through a wire and the frequency of the AC voltage, precise control of different quantities of nanomaterials can be achieved. When the first electrode 2 is grounded through a conductive path, the resistance between the first electrode 2 and the ground is small, and they can be considered to be directly connected. When the first electrode 2 is not grounded through a wire, since the substrate 1 cannot be completely insulated, a large resistor can be considered to be connected in series between the first electrode 2 and the ground. The value of this large resistor is determined by the degree of insulation of the substrate 1. Please refer to [link to relevant documentation]. Figure 7 The diagram illustrates the voltage change between the second and third electrodes before and after deposition in this embodiment. For example, at 5 kHz, with the first electrode 2 grounded via a wire, depositing one nanomaterial can reduce the voltage between the second electrode 4 and the third electrode 5 to approximately 1% of its pre-deposition value. However, with the first electrode 2 not grounded via a wire, depositing 100 nanomaterials would result in such a voltage change. This indicates that under the same frequency and voltage conditions, the first electrode 2 can deposit more nanomaterials without grounding via a wire compared to the first electrode 2 with grounding via a wire. At lower voltage and frequency, a smaller number of nanomaterials can be deposited. The material allows the second electrode 4 and the third electrode 5 to reach a deposition self-stop voltage drop. When the voltage frequency is high, the deposition of a large number of nanomaterials can cause the second electrode 4 and the third electrode 5 to reach a deposition self-stop voltage drop, indicating that the amount of nanomaterials deposited at different frequencies is different. The deposition amount can be controlled by adjusting the deposition frequency. Furthermore, the frequency-voltage curve of depositing one nanomaterial through a grounded wire is close to the curve of depositing 100 nanomaterials without grounding the wire, indicating that there is a specific frequency range. It is possible to maintain single-particle deposition between the capture electrodes in the grounded state while controlling the deposition amount between the capture electrodes in the non-grounded state by adjusting the frequency.

[0088] Specifically, please refer to Figure 8The image shown is an electron microscope image of a single nanomaterial formed by grounding the first electrode via a wire, where the applied AC piezoelectric current has an amplitude of 0.8 Vpp and a frequency of 1 kHz; please refer to [link to image]. Figure 9 The image shows an electron microscope image of multiple nanomaterials formed by the first electrode without being grounded by a wire. The applied AC piezoelectric amplitude is 0.8 Vpp and the frequency is 1 kHz.

[0089] Specifically, please refer to Figure 10 The image shows an electron microscope (EM) image of a low-density nanomaterial formed by applying a low-frequency AC piezoelectric voltage to the first electrode with it grounded via a wire. The applied AC piezoelectric voltage has an amplitude of 0.8 Vpp and a frequency of 5 kHz. Please refer to [link to image]. Figure 11 The image shows an electron microscope image of a high-density nanomaterial formed by applying a high-frequency AC voltage to the first electrode while it is grounded via a wire. The applied AC piezoelectric voltage has an amplitude of 0.8 Vpp and a frequency of 10 kHz.

[0090] As an example, the frequency and amplitude of the AC voltage are determined based on parameters such as the resistance of the nanomaterial, the values ​​of the first capacitor and the second capacitor.

[0091] As an example, the first capacitor and the second capacitor constitute a deposition combination; please refer to [link to documentation]. Figure 12 Multiple deposition assemblies are formed on the substrate 1. Depending on the deposition requirements at different locations, the first electrode 2 in each deposition assembly is either grounded via a wire or not. The AC voltage frequency in the deposition assembly is also set as needed to achieve precise control of different quantities of nanomaterials in different regions. Figure 12 Example 1: The electrode array is configured with three deposition combinations, including a first deposition combination 8, a second deposition combination 9, and a third deposition combination 10. The three third electrodes 5 of the three deposition combinations share a common connection terminal. A first quantity of nanomaterials is pre-formed in the region of the first deposition combination 8, a second quantity of nanomaterials is pre-formed in the region of the second deposition combination 9, and a third quantity of nanomaterials is pre-formed in the region of the third deposition combination 10. The first quantity is one nanomaterial, the second quantity is greater than the first quantity, and the third quantity is greater than the second quantity. Specifically, the deposition methods for different quantities are as follows:

[0092] (i) The first electrode 2 in each of the three deposition combinations is grounded through a wire, and then an AC voltage of the first frequency is applied, and each of the three deposition combinations deposits a first amount of nanomaterials;

[0093] (ii) Adjust the frequency of the AC voltage to the second frequency, disconnect the grounding wire of the first electrode 2 in the second deposition combination 9, and the second deposition combination 9 region will continue to deposit the second amount of nanomaterials, while the first electrode 2 in the first deposition combination 8 and the third deposition combination 10 is grounded through the wire and still maintains the first amount. At this time, the first deposition combination 8 region is the first amount of deposition, the second deposition combination 9 region is the second amount of deposition, and the third deposition combination 10 region is the first amount of deposition.

[0094] (III) The first electrode 2 in the second deposition assembly 9 is grounded through a wire, the frequency of the AC voltage is adjusted to the third frequency, and the grounding of the first electrode 2 in the third deposition assembly 10 is disconnected. Then, the third deposition assembly 10 region will continue to deposit the third number of nanomaterials, while the first electrode 2 in the first deposition assembly 8 and the second deposition assembly 9 are grounded through a wire, maintaining the first number in the region of the first deposition assembly 8 and the second number in the region of the second deposition assembly 9. Finally, the first number of depositions in the region of the first deposition assembly 8, the second number of depositions in the region of the second deposition assembly 9, and the third number of depositions in the region of the third deposition assembly 10 are achieved.

[0095] It should be noted that, Figure 12 Only three examples of deposition combinations are listed. In actual devices, more deposition combinations can be set according to requirements to achieve controllable nanomaterial deposition for large-scale array devices.

[0096] As an example, such as Figure 13 As shown, in another example, the first deposition assembly 8, the second deposition assembly 9, and the third deposition assembly 10 are separately configured. For example, the first electrode 2 in the first deposition assembly 8 is grounded via a wire, and an AC voltage of a first frequency is applied to deposit a first quantity of nanomaterials; the first electrode 2 in the second deposition assembly 9 is not grounded via a wire, and an AC voltage of a second frequency is applied to deposit a second quantity of nanomaterials; the first electrode 2 in the third deposition assembly 10 is not grounded via a wire, and an AC voltage of a third frequency is applied to deposit a third quantity of nanomaterials, ultimately achieving the first quantity deposition in the region of the first deposition assembly 8, the second quantity deposition in the region of the second deposition assembly 9, and the third quantity deposition in the region of the third deposition assembly 10. By independently controlling the application of different voltages to different deposition assemblies, controllable nanomaterial deposition of small-scale array devices can be achieved.

[0097] As an example, the nanomaterial preparation method of this embodiment can be applied to the preparation of devices with different performance in different regions in the construction of a physical reservoir computing system.

[0098] As described above, in the nanomaterial preparation method of this embodiment, the deposition of nanomaterials is self-terminated by dividing the voltage of the second capacitor by the first capacitor, so as to precisely control the deposition quantity of nanomaterials; and, by adjusting whether the first electrode in different regions is grounded through a wire and the AC voltage frequency, the precise control of different positions and different quantities of nanomaterials is achieved, so as to realize the array deposition of nanomaterials with controllable quantity.

[0099] Example 2

[0100] This embodiment provides a method for preparing nanomaterials, specifically for preparing high-resistivity semiconductor nanomaterials. In the preparation method of Embodiment 1, when the deposited nanomaterial is a high-resistivity material, the resistance between the second electrode 4 and the third electrode 5 is not easily changed or changes very little after deposition, making it impossible to achieve self-stopping deposition and precise deposition. The purpose of this embodiment is to achieve precise deposition of high-resistivity semiconductor nanomaterials.

[0101] Specifically, the main difference between this embodiment and Embodiment 1 is as follows:

[0102] (a) such as Figure 14 As shown, during the formation of the first electrode 2, a fourth electrode 11 is also formed;

[0103] (ii) Figure 15 As shown, the insulating layer 3 covers the first electrode 2 and the fourth electrode 11;

[0104] (III) Figure 16 As shown, the second electrode 4 and the third electrode 5 are formed on the insulating layer 3, and the projection of the fourth electrode 11 on the substrate 1 connects / crosses the projections of the second electrode 4 and the third electrode 5 on the substrate 1.

[0105] (iv) such as Figure 17 As shown, the deposition source 6 is provided;

[0106] (V) such as Figure 18 As shown, a high-frequency AC voltage is applied to the third electrode 5, and under the action of dielectrophoresis, the nanomaterial 7 is deposited between the second electrode 4 and the third electrode 5.

[0107] As an example, the nanomaterial 7 in this embodiment is a high-resistivity semiconductor, such as a semiconductor carbon nanotube with a resistance of up to 100 MΩ. The fourth electrode 11 directly below the nanomaterial 7 can be regarded as a gate (back gate). By applying a DC voltage to the fourth electrode 11, the electrical characteristics of the nanomaterial 7 are controlled and its resistance is adjusted to significantly increase the voltage difference between the second electrode 4 and the third electrode 5 before and after the deposition of the nanomaterial 7, thereby achieving self-stopping deposition and precise deposition of the nanomaterial.

[0108] For example, please refer to Figure 19 The first electrode 2, the second electrode 4, and the third electrode 5 constitute a deposition assembly. Multiple deposition assemblies are formed on the substrate 1. According to the deposition requirements at different locations, the first electrode 2 in the deposition assembly is set to be grounded by a wire or not, and the AC voltage frequency in the deposition assembly is set according to the requirements to achieve precise control of different amounts of nanomaterials in different regions.

[0109] As described above, in the nanomaterial preparation method of this embodiment, the resistance of the high-resistivity nanomaterial is adjusted by controlling the electrical properties of the high-resistivity nanomaterial through the fourth electrode, thereby achieving self-stopping deposition and realizing precise deposition of the high-resistivity nanomaterial.

[0110] Example 3

[0111] This embodiment provides a nanomaterial deposition apparatus for depositing low-resistivity nanomaterials. Please refer to [link to relevant documentation]. Figure 6 The nanomaterial deposition apparatus includes: a substrate 1, a first electrode 2, an insulating layer 3, a second electrode 4, and a third electrode 5. The first electrode 2 is located on the substrate 1; the insulating layer 3 is located on the substrate 1 and covers the first electrode 2; the second electrode 4 is located on the insulating layer 3; the third electrode 5 is located on the insulating layer 3. On the projection of the substrate 1, the first electrode 2 and the second electrode 4 overlap, but the first electrode 2 and the third electrode 5 do not overlap. The first electrode 2, the second electrode 4, and the insulating layer 3 between the first electrode 2 and the second electrode 4 constitute a first capacitor. When an AC voltage is applied to the third electrode 5, the first capacitor divides the voltage between the second electrode 4 and the third electrode 5.

[0112] As an example, the substrate 1 is an insulating substrate, or the substrate 1 is a conductive substrate with an insulating film on its surface, including but not limited to intrinsic silicon, flexible polymers, doped silicon with a silicon dioxide insulating film on its surface, etc.

[0113] As an example, nanomaterials can be formed between the second electrode 4 and the third electrode 5 under the action of dielectrophoresis; after the nanomaterials are formed between the second electrode 4 and the third electrode 5, the resistance between the second electrode 4 and the third electrode 5 changes, the voltage between the second electrode 4 and the third electrode 5 decreases, hindering the subsequent deposition of nanomaterials, and realizing the self-stopping of deposition.

[0114] As an example, by controlling whether the first electrode 2 is grounded through a wire and the frequency of the AC voltage, precise control of different quantities of nanomaterials can be achieved. For specific control methods, please refer to Example 1, which will not be described in detail here.

[0115] As an example, the first electrode 2, the second electrode 4, and the third electrode 5 constitute a deposition assembly. (See [link to documentation]). Figure 12 Multiple deposition combinations are formed on the substrate 1. According to the deposition requirements of different locations, the first electrode 2 in the deposition combination is set to be grounded by a wire or not, and the AC voltage frequency in the deposition combination is set according to the requirements, so as to achieve precise control of different amounts of nanomaterials in different regions.

[0116] As described above, in the nanomaterial deposition apparatus of this embodiment, the voltage between the second and third electrodes is divided by the first capacitor to achieve self-termination of nanomaterial deposition; and, by adjusting whether the first electrode in different regions is grounded through a wire and the AC voltage frequency, precise control of nanomaterials in different positions and quantities can be achieved, thereby realizing array deposition of nanomaterials with controllable quantity.

[0117] Example 4

[0118] This embodiment provides a nanomaterial deposition apparatus for depositing high-resistivity semiconductor nanomaterials. Please refer to [link to relevant documentation]. Figure 18 The difference between the nanomaterial deposition device in this embodiment and that in embodiment three is that it further includes a fourth electrode 11, which is located on the substrate 1. The insulating layer 3 covers the fourth electrode 11, and the projection of the fourth electrode 11 on the substrate 1 connects / crosses the projections of the second electrode 4 and the third electrode 5 on the substrate 1.

[0119] As an example, when the nanomaterial 7 formed between the second electrode 4 and the third electrode 5 is a high-resistivity semiconductor, the resistance between the second electrode 4 and the third electrode 5 before and after the deposition of the nanomaterial 7 is not easily changed or changes very little, making it impossible to achieve self-stop deposition. The fourth electrode 11 directly below the nanomaterial 7 can be regarded as a gate (back gate). By applying a DC voltage to the fourth electrode 11, the electrical characteristics of the nanomaterial 7 can be controlled, and its resistance can be adjusted to significantly increase the voltage difference between the second electrode 4 and the third electrode 5 before and after the deposition of the nanomaterial, thereby achieving self-stop deposition and precise deposition of the nanomaterial.

[0120] As an example, the first electrode 2, the second electrode 4, and the third electrode 5 constitute a deposition assembly. (See also...) Figure 19 Multiple deposition combinations are formed on the substrate 1. According to the deposition requirements of different locations, the first electrode 2 in the deposition combination is set to be grounded by a wire or not, and the AC voltage frequency in the deposition combination is set according to the requirements, so as to achieve precise control of different amounts of nanomaterials in different regions.

[0121] In summary, the nanomaterial preparation method and deposition apparatus of this invention utilize a first capacitor to divide the voltage between the second and third electrodes, achieving self-termination of nanomaterial deposition and precisely controlling the amount of nanomaterials deposited. Furthermore, by adjusting whether the first electrode in different regions is grounded via a wire and the AC voltage frequency, precise control over the quantity of nanomaterials at different locations is achieved, enabling controllable array deposition of nanomaterials. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and possesses high industrial applicability.

[0122] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing nanomaterials, characterized in that, Includes the following steps: A substrate is provided, and a first electrode is formed on the substrate; An insulating layer covering the first electrode is formed on the substrate; A second electrode and a third electrode are formed on the insulating layer. On the projection of the substrate, the first electrode and the second electrode overlap, and the first electrode and the third electrode do not overlap. The first electrode, the second electrode, and the insulating layer between the first electrode and the second electrode constitute a first capacitor. A deposition source is provided, the deposition source being at least located between the second electrode and the third electrode. The second electrode, the third electrode, and the deposition source between the second electrode and the third electrode constitute a second capacitor. An AC voltage is applied to the third electrode, and nanomaterials are formed between the second electrode and the third electrode under dielectrophoresis. After the nanomaterials are formed, the resistance between the second electrode and the third electrode changes, while the resistance between the first electrode and the second electrode does not change. The first capacitor divides the voltage of the second capacitor.

2. The method for preparing nanomaterials according to claim 1, characterized in that: The first capacitor and the second capacitor constitute a deposition assembly, wherein a plurality of the deposition assemblies are formed on the substrate.

3. The method for preparing nanomaterials according to claim 2, characterized in that: In the deposition assembly at the preset location, the first electrode is grounded via a wire, or the first electrode is not grounded via a wire.

4. The method for preparing nanomaterials according to claim 2, characterized in that: In the deposition combinations at different locations, the frequency of the AC voltage is the same; or the frequency of the AC voltage is not the same.

5. The method for preparing nanomaterials according to any one of claims 1-4, characterized in that: The nanomaterial is a semiconductor material. Before forming the insulating layer, the step of forming a fourth electrode on the substrate is further included. The insulating layer covers the fourth electrode. The projection of the fourth electrode on the substrate connects / crosses the projections of the second electrode and the third electrode on the substrate.

6. A nanomaterial deposition device, characterized in that, include: Substrate; The first electrode is located on the substrate; An insulating layer is located on the substrate and covers the first electrode; The second electrode is located on the insulating layer; The third electrode is located on the insulating layer. On the projection of the substrate, the first electrode and the second electrode overlap, but the first electrode and the third electrode do not overlap. The first electrode, the second electrode, and the insulating layer between the first electrode and the second electrode constitute a first capacitor. When an AC voltage is applied to the third electrode, the first capacitor divides the voltage between the second electrode and the third electrode.

7. The nanomaterial deposition apparatus according to claim 6, characterized in that: The first electrode, the second electrode, and the third electrode constitute a deposition assembly, wherein a plurality of the deposition assemblies are provided on the substrate.

8. The nanomaterial deposition apparatus according to claim 7, characterized in that: In the deposition assembly at the preset location, the first electrode is grounded via a wire, or the first electrode is not grounded via a wire.

9. The nanomaterial deposition apparatus according to claim 7, characterized in that: In the deposition combinations at different locations, the frequency of the AC voltage is the same; or the frequency of the AC voltage is not the same.

10. The nanomaterial deposition apparatus according to any one of claims 6-9, characterized in that: It also includes a fourth electrode located on the substrate, the insulating layer covering the fourth electrode, and the projection of the fourth electrode on the substrate connecting / across the projections of the second electrode and the third electrode on the substrate.

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