Preparation method of nanostructure and nanostructure

Abstract

The present invention provides a method for preparing a nanostructure and the nanostructure. The method for preparing the nanostructure forms a stack by alternately and repeatedly laminating a first material layer and a second material layer on a substrate; then forms a groove pattern on the upper surface of the stack, etches the stack to the surface of the substrate, and transfers the groove pattern into the stack; then fills a molding material into the groove pattern of the stack, and removes the remaining first material layer or second material layer in the stack, so as to form an array of nanopore patterns in the stack. Compared with the existing method, it can not only ensure that the nanopore patterns are arranged in a regular geometric array, but also control the diameter and density of the nanopores by adjusting the groove spacing of the groove pattern, the thicknesses of the first material layer and the second material layer.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano sieve pores, and particularly to a preparation method of a nanostructure and a nanostructure. Background Art

[0002] Micro-nano sieve pore channel materials have very wide application values in the fields of biology / medicine, such as DNA sequencing, macromolecule detection, nano templates, drug delivery, etc. At present, there are mainly two types of schemes for manufacturing micro-nano sieve pores: the first type uses chemically synthesized materials, such as porous metal oxide films formed by anodic oxidation and chemical etching. The disadvantage of this scheme is that the pore size cannot be controlled to be uniform, and the distribution cannot form a regular array; the second type is to use the processing method of integrated circuits by combining photolithography and etching, which can prepare pores with consistent sizes and a geometrically regular pore array, but the diameter and density of the pores are limited by photolithography and etching technologies. Summary of the Invention

[0003] The present invention provides a preparation method of a nanostructure and a nanostructure, which can not only ensure that the nano-pore pattern is arranged in a regular geometric array, but also control the diameter and density of the nano-pores by adjusting the groove spacing of the groove pattern, and the thicknesses of the first material layer and the second material layer.

[0004] In a first aspect, the present invention provides a preparation method of a nanostructure, and the preparation method includes:

[0005] Providing a substrate;

[0006] Alternately and repeatedly laminating a first material layer and a second material layer on the substrate to form a laminated layer; wherein, the etching selectivity ratios of the first material layer and the second material layer are different;

[0007] Forming a mask on the upper surface of the laminated layer, and forming a groove pattern in the mask; wherein, the groove pattern includes a plurality of grooves arranged side by side, and the bottom wall of each groove is the upper surface of the laminated layer;

[0008] Etching the laminated layer from top to bottom to the upper surface of the substrate, and transferring the groove pattern to the laminated layer;

[0009] Filling a molding material in the groove pattern in the laminated layer, and performing planarization treatment on the molding material until it reaches the upper surface of the laminated layer;

[0010] Removing the remaining first material layer or second material layer in the laminated layer to form an arrayed nano-pore pattern in the laminated layer.

[0011] In the above solution, a stack is formed by alternately and repeatedly laminating a first material layer and a second material layer on a substrate; then a groove pattern is formed on the upper surface of the stack, and the stack is etched to the surface of the substrate to transfer the groove pattern into the stack; then a molding material is filled into the groove pattern of the stack, and the remaining first material layer or second material layer in the stack is removed, so as to form an array of nanopore patterns in the stack. Compared with the existing method, it can not only ensure that the nanopore patterns are arranged in a regular geometric array, but also control the diameter and density of the nanopores by adjusting the groove spacing of the groove pattern, the thickness of the first material layer and the second material layer.

[0012] In a specific embodiment, the molding material is silicon dioxide or aluminum oxide, which improves the stiffness and stability of the formed nanostructure.

[0013] In a specific embodiment, the material of the first material layer is a silicon-germanium material, and the material of the second material layer is silicon, which is convenient for depositing and etching the first material layer and the second material layer by using semiconductor deposition and etching processes.

[0014] In a specific embodiment, the concentration of germanium in the silicon-germanium material is 5% - 100%, so that the first material layer and the second material layer have a large etching selectivity ratio, which is convenient for removing the first material layer or the second material layer by using a selective etching process.

[0015] In a specific embodiment, the thicknesses of both the first material layer and the second material layer are between 0.5 nm and 100 nm, and the total number of the first material layer and the second material layer included in the stack is 2 - 1000 layers, which is convenient for adjusting the pore diameter and density of the nanopores within a large range.

[0016] In a specific embodiment, removing the remaining first material layer or second material layer in the stack to form an array of nanopore patterns in the stack includes: using a gaseous etching or liquid etching method to remove the remaining first material layer or second material layer in the stack, which is convenient for removing the remaining first material layer and second material layer in the stack.

[0017] In a specific embodiment, when using the gaseous etching method to remove the remaining first material layer or second material layer in the stack, the etching gas used in the gaseous etching is ClF 3 、CF 4 / O 2 / He composition mixed gas, or NF 3 / NH 3 / O 2 composition mixed gas, which improves the efficiency and effect of gaseous etching. When using the liquid etching method to remove the remaining first material layer or second material layer in the stack, the etching liquid used in the liquid etching is CH 3COOH / H 2 O 2 A mixed liquid composed of / HF is used to improve the effect and efficiency of liquid etching.

[0018] In a specific embodiment, a mask is formed on the upper surface of the stack, and a wire groove pattern is formed in the mask, including: using a direct lithography patterning process, or a sidewall transfer patterning process, or a lithography + sidewall transfer patterning process to form a mask on the upper surface of the stack and form a wire groove pattern in the mask. This facilitates adjusting the width of the wire grooves in the wire groove pattern, and further adjusting the pore diameter of the processed nanopores.

[0019] In a specific embodiment, a lithography + sidewall transfer patterning process is used to form a mask on the upper surface of the stack and form a wire groove pattern in the mask, including:

[0020] Deposit a transition mask on the upper surface of the stack;

[0021] Use a direct lithography patterning process to form a transition wire groove pattern in the transition mask; wherein, the transition wire groove pattern contains a plurality of transition wire grooves arranged side by side, and the bottom wall of each transition wire groove is the upper surface of the stack;

[0022] Deposit a mask on the sidewalls of the transition wire groove pattern and the protruding surfaces between adjacent transition wire grooves;

[0023] Use an anisotropic etching process to etch away the mask on the protruding surfaces between adjacent transition wire grooves;

[0024] Remove the remaining transition mask, and the remaining mask forms sidewalls, and a wire groove in the wire groove pattern is formed between two adjacent sidewalls. This facilitates processing a nanopore structure with a smaller pore diameter.

[0025] In a second aspect, the present invention also provides a nanostructure, which is a nanostructure prepared by using the preparation method of any one of the above nanostructures. First, a first material layer and a second material layer are alternately and repeatedly stacked on a substrate to form a stack; then a wire groove pattern is formed on the upper surface of the stack, and the stack is etched to the surface of the substrate to transfer the wire groove pattern into the stack; then a molding material is filled in the wire groove pattern of the stack, and the remaining first material layer or second material layer in the stack is removed, so as to form an array of nanopore patterns in the stack. Compared with the existing method, it can not only ensure that the nanopore patterns are arranged in a regular geometric array, but also control the diameter and density of the nanopores by adjusting the wire groove spacing of the wire groove pattern, and the thicknesses of the first material layer and the second material layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flowchart of a preparation method of a nanostructure provided by an embodiment of the present invention;

[0027] Figures 2 to 12 This is a schematic cross-sectional view of each step in the method for preparing a nanostructure provided by an embodiment of the present invention.

[0028] Reference numerals:

[0029] 10 - Substrate; 11 - First material layer; 12 - Second material layer; 20 - Mask; 21 - Groove; 30 - Forming material

[0030] 40 - Nanopore; 51 - Transition mask; 52 - Photoresist; 53 - Transition groove; 54 - Sidewall Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] To facilitate understanding of the method for preparing a nanostructure provided by an embodiment of the present invention, the application scenario of the method for preparing a nanostructure provided by an embodiment of the present invention will be first described below. The method for preparing a nanostructure is applied to the preparation process of a nanopore array. The method for preparing a nanostructure will be described in detail below with reference to the accompanying drawings.

[0033] Refer to Figure 1 , the method for preparing a nanostructure provided by an embodiment of the present invention includes:

[0034] Step10: Provide a substrate 10;

[0035] Step20: Alternately and repeatedly stack a first material layer 11 and a second material layer 12 on the substrate 10 to form a stack; wherein, the etching selectivity ratios of the first material layer 11 and the second material layer 12 are different;

[0036] Step30: Form a mask 20 on the upper surface of the stack, and form a groove pattern 21 in the mask 20; wherein, the groove pattern 21 includes a plurality of grooves 21 arranged side by side, and the bottom wall of each groove 21 is the upper surface of the stack;

[0037] Step40: Etch the stack from top to bottom to the upper surface of the substrate 10, and transfer the groove pattern 21 to the stack;

[0038] Step50: Fill the groove pattern 21 in the stack with a forming material 30, and perform planarization treatment on the forming material 30 until it reaches the upper surface of the stack;

[0039] Step 60: Remove the remaining first material layer 11 or second material layer 12 in the stack to form a pattern of nanopores 40 arranged in an array within the stack.

[0040] In the above solution, by alternately and repeatedly stacking the first material layer 11 and the second material layer 12 on the substrate 10 first, a stack is formed; then a groove pattern 21 is formed on the upper surface of the stack, and the stack is etched to the surface of the substrate 10 to transfer the groove pattern 21 into the stack; then a molding material 30 is filled in the groove pattern 21 of the stack, and the remaining first material layer 11 or second material layer 12 in the stack is removed, so as to form a pattern of nanopores 40 arranged in an array within the stack. Compared with the existing method, it can not only ensure that the nanopore pattern 40 is arranged in a regular geometric array, but also control the diameter and density of the nanopores 40 by adjusting the groove spacing of the groove pattern 21, the thickness of the first material layer 11 and the second material layer 12. The following will introduce each of the above steps in detail with reference to the accompanying drawings.

[0041] First, refer to Figure 1 and Figure 2 , a substrate 10 is provided. The substrate 10 can specifically be a silicon substrate 10 or a substrate 10 made of other materials, and the upper surface of the substrate 10 has a flat surface area. The shape of the substrate 10 can specifically be rectangular or circular, etc. Preferably, a rectangular substrate 10 can be used.

[0042] Next, refer to Figure 1 and Figure 2 , the first material layer 11 and the second material layer 12 are alternately and repeatedly stacked on the substrate 10 to form a stack. Among them, the etching selectivity ratios of the first material layer 11 and the second material layer 12 are different. When alternately stacking the first material layer 11 and the second material layer 12, as Figure 2 shown, the first material layer 11 can be deposited on the substrate 10 first, then the second material layer 12 is deposited on the first material layer 11, and then the first material layer 11 is stacked on the second material layer 12, and the growth is repeated alternately in sequence. It should be noted that the number of layers of the first material layer 11 and the second material layer 12 in the stack can be equal or not equal. As Figure 2 shown, the number of layers of the first material layer 11 is one more than the number of layers of the second material layer 12.

[0043] When determining the materials of the first material layer 11 and the second material layer 12, the materials in the first material layer 11 and the second material layer 12 can be silicon and silicon germanium materials respectively, so that there is a large etching selectivity ratio between the two material layers. Of course, it should be noted that the material selection method of the first material layer 11 and the second material layer 12 is not limited to the above-mentioned materials of silicon or germanium-silicon materials. In addition, other methods can also be used.

[0044] Exemplarily, the material of the first material layer 11 can be silicon germanium material, and the material of the second material layer 12 can be silicon, which is convenient for depositing and etching the first material layer 11 and the second material layer 12 by using semiconductor deposition and etching processes. At this time, the concentration of germanium in the silicon germanium material can be any value between 5% and 100%, such as 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc., so that the first material layer 11 and the second material layer 12 have a large etching selectivity, which is convenient for removing the first material layer 11 or the second material layer 12 by using a selective etching process.

[0045] In addition, the thicknesses of the first material layer 11 and the second material layer 12 can both be in the range of 0.5 nm to 100 nm. Specifically, the thicknesses of the first material layer 11 and the second material layer 12 can be any value between 0.5 nm and 100 nm, such as 0.5 nm, 5 nm, 15 nm, 25 nm, 35 nm, 45 nm, 55 nm, 65 nm, 75 nm, 85 nm, 95 nm, 100 nm, etc. It should be noted that the pore diameter of the nanopore 40 in the vertical direction and the distribution density of the nanopore 40 in the vertical direction can be adjusted by adjusting the thicknesses of the first material layer 11 and the second material layer 12. Figures 2 to 11 For example, the second material layer 12 remaining after etching forms the nanopore 40. At this time, the thicker the thickness of the first material layer 11, the sparser the distribution density of the nanopore 40 in the vertical direction; the thinner the thickness of the first material layer 11, the denser the distribution density of the nanopore 40 in the vertical direction. The thicker the thickness of the second material layer 12, the larger the pore diameter of the nanopore 40 in the vertical direction; the thinner the thickness of the second material layer 12, the smaller the pore diameter of the nanopore 40 in the vertical direction. The total number of layers of the first material layer 11 and the second material layer 12 included in the stacked layer can be 2 to 1000 layers, that is, the total number of layers of the first material layer 11 and the second material layer 12 can be 3 layers, 100 layers, 300 layers, 500 layers, 800 layers, 1000 layers, etc., which is convenient for adjusting the pore diameter and density of the nanopore 40 within a large range.

[0046] Next, referring to Figure 1 and Figures 3 to 8, a mask 20 is formed on the upper surface of the stack, and a wire groove 21 pattern is formed in the mask 20; wherein, the wire groove 21 pattern includes a plurality of wire grooves 21 arranged side by side, and the bottom wall of each wire groove 21 is the upper surface of the stack. In this step, specifically, the distance between two adjacent wire grooves 21 in the wire groove 21 pattern can be adjusted to adjust the aperture size of the finally formed nanopore 40 in the horizontal direction. If the distance between two adjacent wire grooves 21 is smaller, the aperture size of the formed nanopore 40 in the horizontal direction is smaller; if the distance between two adjacent wire grooves 21 is larger, the aperture size of the formed nanopore 40 in the horizontal direction is larger. Correspondingly, the width of the wire groove 21 in the wire groove 21 pattern can be adjusted to adjust the distribution density of the nanopores 40 in the horizontal direction. If the width of the wire groove 21 is larger, the distribution density of the nanopores 40 in the horizontal direction is sparser; if the width of the wire groove 21 is smaller, the distribution density of the nanopores 40 in the horizontal direction is denser.

[0047] Specifically, when forming the mask 20 on the upper surface of the stack and forming the wire groove 21 pattern in the mask 20, a direct photolithography patterning process, or a sidewall transfer patterning process, or a photolithography + sidewall transfer patterning process can be used to form the mask 20 on the upper surface of the stack and form the wire groove 21 pattern in the mask 20. This is convenient for adjusting the width of the wire groove 21 in the wire groove 21 pattern, and further adjusting the aperture size of the processed nanopore 40. When using the direct photolithography patterning process, the distance and width of the processed wire grooves 21 are limited by the accuracy of the photolithography process. When using the sidewall transfer patterning process, the distance between the wire grooves 21 can be reduced by the number of sidewall transfers, thereby reducing the aperture size of the nanopore 40 in the horizontal direction. Of course, the photolithography process can also be incorporated into the sidewall transfer patterning process, and a photolithography + sidewall transfer patterning process can be used to form the mask 20 on the upper surface of the stack and form the wire groove 21 pattern in the mask 20.

[0048] Exemplarily, such as Figures 3 to 8As shown, when using a lithography + sidewall transfer patterning process to form a mask 20 on the upper surface of the stack and form a groove 21 pattern in the mask 20, a transition mask 51 can be first deposited on the upper surface of the stack. The material of the transition mask 51 can be silicon nitride. Then, using a direct lithography patterning process, a transition groove 53 pattern is formed in the transition mask 51. Among them, the transition groove 53 pattern contains a plurality of transition grooves 53 arranged side by side. The bottom wall of each transition groove 53 is the upper surface of the stack. Specifically, the transition groove 53 pattern can be first transferred to a photoresist 52, and then, an etching process (which can be a dry plasma etching process, etc.) is used to transfer the transition groove 53 pattern to the transition mask 51. Then, a mask 20 is deposited on the sidewalls of the transition groove 53 pattern and the raised surfaces between adjacent transition grooves 53. Specifically, ALD, CVD or LPCVD technology can be used to deposit the mask 20 on the sidewalls of the transition groove 53 pattern and the raised surfaces between adjacent transition grooves 53. The material of the mask 20 can be different from that of the transition mask 51. For example, it can be a material such as silicon dioxide, which is convenient for subsequent selective etching to remove the remaining transition mask 51. Then, an anisotropic etching process is used to etch away the mask 20 on the raised surfaces between adjacent transition grooves 53. Then, the remaining transition mask 51 is removed (the remaining transition mask 51 can be etched away by a wet etching process such as phosphoric acid etching), and the remaining mask 20 forms a sidewall 54 pattern. A groove 21 in the groove 21 pattern is formed between two adjacent sidewalls 54. This is convenient for processing a nanopore 40 structure with a smaller aperture.

[0049] Next, referring to Figure 9 , the stack is etched from top to bottom to the upper surface of the substrate 10, and the groove 21 pattern is transferred to the stack. Specifically, a wet etching process can be used to etch the stack from top to bottom to the upper surface of the substrate 10. Phosphoric acid or other etching solutions can be used to etch the stack from top to bottom to the upper surface of the substrate 10.

[0050] Next, referring to Figure 10 , a molding material 30 is filled in the groove 21 pattern in the stack, and the molding material 30 is planarized to the upper surface of the stack. The molding material 30 can specifically be silicon dioxide or aluminum oxide to improve the stiffness and stability of the formed nanostructure. Of course, other molding materials 30 can also be used. After filling the molding material 30, a chemical mechanical polishing process can be used to planarize the molding material 30 and remove the sidewall 54 to the upper surface of the stack.

[0051] Next, referring to Figure 11 , the remaining first material layer 11 or second material layer 12 in the stack is removed to form an array of nanopore 40 patterns in the stack. Exemplarily, as Figure 11As shown, the remaining second material layer 12 in the stack is removed, and a pattern of nanopores 40 arranged in an array is formed in the stack. In Figure 11 , the extending direction of the nanopores 40 is perpendicular to the plane of the paper.

[0052] Exemplarily, when removing the remaining first material layer 11 or second material layer 12 in the stack and forming a pattern of nanopores 40 arranged in an array within the stack, a gaseous etching or liquid etching method can be used to remove the remaining first material layer 11 or second material layer 12 in the stack, facilitating the removal of the remaining first material layer 11 and second material layer 12 in the stack. Specifically, when using the gaseous etching method to remove the remaining first material layer 11 or second material layer 12 in the stack, the etching gas used in the gaseous etching is ClF 3 , CF 4 / O 2 / He - composed mixed gas, or NF 3 / NH 3 / O 2 - composed mixed gas, improving the efficiency and effect of the gaseous etching. When using the liquid etching method to remove the remaining first material layer 11 or second material layer 12 in the stack, the etching liquid used in the liquid etching is CH 3 COOH / H 2 O 2 / HF - composed mixed liquid, improving the effect and efficiency of the liquid etching.

[0053] As Figure 11 shown, the cross - section of the nanopores prepared by the above - shown method is rectangular. In a more preferred embodiment, the cross - section of the nanopores can be made square by adjusting the thickness of the second material layer and the width of the sidewall.

[0054] In addition, referring to Figure 11 and Figure 12 , the nanopores with a rectangular cross - section can also be rounded to obtain nanopores with a circular cross - section to meet the corresponding usage requirements. Specifically, when rounding the nanopores with a rectangular cross - section, an alternating method of oxidation and de - oxidation layer can be used to round the corners of the rectangle. Among them, the above - mentioned oxidation treatment method can be to place the semiconductor structure in a high - temperature environment filled with O 2 , at a temperature of 1050 °C, to oxidize the nanopores with a rectangular cross - section in the semiconductor structure to form an oxide layer. Of course, other oxidation treatment methods can also be used. For example, an oxygen ion oxidation method at room temperature can also be used, or it can also be filled with H 2 O 2 , O 3 , or HNO 3Oxidation is carried out in a gas environment such as the above. The above method of removing the oxide layer can selectively remove the oxide layer with HF in a ratio of 10:1 to 100:1. During the rounding process, the above methods of oxidation and removing the oxide layer can be alternately repeated, so that the rectangular cross-section nanopores can be continuously corrected into circular cross-section nanopores.

[0055] Of course, the above method of rounding the nanopores with a rectangular cross-section can also adopt other methods. For example, in an environment of 500-1000 °C, using H 2 Annealing can also make the sharp corners of the rectangular cross-section disappear and become a circular cross-section, thereby forming nanopores with a circular cross-section.

[0056] It should be explained that the principles of the above rounding processes are all based on the spontaneous driving direction in which the surface energy of the nanopores tends to decrease. Just as a burr-bearing metal will be polished when placed in a chemical solution for corrosion, it is consistent with the mechanism of rounding the nanopores with a rectangular cross-section.

[0057] In the various embodiments shown above, by alternately and repeatedly laminating the first material layer 11 and the second material layer 12 on the substrate 10 first, a stack is formed; then a wire groove 21 pattern is formed on the upper surface of the stack, and the stack is etched to the surface of the substrate 10 to transfer the wire groove 21 pattern into the stack; then a molding material 30 is filled in the wire groove 21 pattern of the stack, and the remaining first material layer 11 or the second material layer 12 in the stack is removed, so as to form an array of nanopore 40 patterns in the stack. Compared with the existing method, it can not only ensure that the nanopore 40 patterns are arranged in a regular geometric array, but also control the diameter and density of the nanopores 40 by adjusting the wire groove 21 spacing of the wire groove 21 pattern, the thickness of the first material layer 11 and the second material layer 12.

[0058] In addition, the embodiment of the present invention also provides a nanostructure, which is a nanostructure prepared by using the preparation method of any one of the above nanostructures. By alternately and repeatedly laminating the first material layer 11 and the second material layer 12 on the substrate 10 first, a stack is formed; then a wire groove 21 pattern is formed on the upper surface of the stack, and the stack is etched to the surface of the substrate 10 to transfer the wire groove 21 pattern into the stack; then a molding material 30 is filled in the wire groove 21 pattern of the stack, and the remaining first material layer 11 or the second material layer 12 in the stack is removed, so as to form an array of nanopore 40 patterns in the stack. Compared with the existing method, it can not only ensure that the nanopore 40 patterns are arranged in a regular geometric array, but also control the diameter and density of the nanopores 40 by adjusting the wire groove 21 spacing of the wire groove 21 pattern, the thickness of the first material layer 11 and the second material layer 12.

[0059] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for preparing a nanostructure, characterized in that, comprising: providing a substrate; alternately and repeatedly stacking a first material layer and a second material layer on the substrate to form a stack; wherein, the etching selectivity ratios of the first material layer and the second material layer are different; forming a mask on the upper surface of the stack, and forming a wire groove pattern in the mask; wherein, the wire groove pattern includes a plurality of wire grooves arranged side by side, and the bottom wall of each wire groove is the upper surface of the stack; etching the stack from top to bottom to the upper surface of the substrate to transfer the wire groove pattern into the stack; filling a molding material into the wire groove pattern in the stack, and planarizing the molding material until it reaches the upper surface of the stack; removing the remaining first material layer or second material layer in the stack by gaseous etching or liquid etching to form an array of nanopore patterns in the stack.

2. The preparation method according to claim 1, characterized in that, the molding material is silicon dioxide or aluminum oxide.

3. The preparation method according to claim 1, characterized in that, the material of the first material layer is a silicon-germanium material, and the material of the second material layer is silicon.

4. The preparation method according to claim 3, characterized in that, the concentration of germanium in the silicon-germanium material is 5% to 100%.

5. The preparation method according to claim 1, characterized in that, the thicknesses of both the first material layer and the second material layer are between 0.5 nm and 100 nm, and the total number of layers of the first material layer and the second material layer included in the stack is 2 to 1000 layers.

6. The preparation method according to claim 1, characterized in that, the removing the remaining first material layer or second material layer in the stack to form an array of nanopore patterns in the stack includes: removing the remaining first material layer or second material layer in the stack by gaseous etching or liquid etching.

7. The preparation method according to claim 6, characterized in that, When removing the remaining first material layer or second material layer in the stack using a gaseous etching method, the etching gas used during the gaseous etching is ClF 3 , CF 4 / O 2 / He composition of the mixed gas, or NF 3 / NH 3 / O 2 composition of the mixed gas; When removing the remaining first material layer or second material layer in the stack using a liquid etching method, the etching liquid used during the liquid etching is a mixed liquid composed of CH 3 COOH / H 2 O 2 / HF.

8. The preparation method according to claim 1, characterized in that, the forming a mask on the upper surface of the stack and forming a wire groove pattern in the mask includes: forming a mask on the upper surface of the stack and forming a wire groove pattern in the mask by using a direct photolithography patterning process, or a sidewall transfer patterning process, or a photolithography + sidewall transfer patterning process.

9. The preparation method according to claim 8, characterized in that, the forming a mask on the upper surface of the stack and forming a wire groove pattern in the mask by using a photolithography + sidewall transfer patterning process includes: depositing a transition mask on the upper surface of the stack; forming a transition wire groove pattern in the transition mask by using a direct photolithography patterning process; wherein, the transition wire groove pattern includes a plurality of transition wire grooves arranged side by side, and the bottom wall of each transition wire groove is the upper surface of the stack; depositing a mask on the sidewalls of the transition wire groove pattern and on the protruding surfaces between adjacent transition wire grooves; using an anisotropic etching process to etch away the mask on the protruding surfaces between adjacent transition wire grooves; Remove the remaining transition mask, and the remaining mask forms sidewalls, and a trench in the trench pattern is formed between two adjacent sidewalls.

10. A nanostructure, characterized in that the nanostructure is a nanostructure prepared by using the preparation method of the nanostructure according to any one of claims 1 to 9.

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