Nano porous structure processing method based on ice etching

Abstract

The invention discloses a nano porous structure processing method based on ice etching, which comprises the following steps: (1) mixing at least two gaseous substances in a mixing cavity in proportion to obtain mixed gas; (2) forming an ice film of the mixed gas on a surface in a low-temperature environment; (3) carrying out electron beam exposure on the mixed gas ice film; and raising the temperature to remove the unexposed part of the mixed ice film to obtain the nano-porous structure. By means of the method, the high-precision patterned porous nanostructure can be machined, and the machining precision can reach submicron or below. The whole process from gas mixing and injection to the surface of a low-temperature cooled sample to sublimation of an unexposed mixed ice film on the surface of the sample through temperature rise is free of environmental pollution, one-time machining forming is achieved, and the method has good application prospects in the aspects of optics, sensing, mechanics and the like.

Description

A method for fabricating nanoporous structures based on ice etching Technical Field

[0001] This invention belongs to the field of micro-nano fabrication, specifically relating to inorganic / organic nanomaterial preparation technology, and particularly to a fabrication process based on ice etching technology to achieve patternable and tunable nanoporous structures. Background Technology

[0002] Nanoporous structures, due to their high specific surface area, tunable mass transfer properties, and potential lightweight and high-strength characteristics, have wide applications in optics, sensing, energy storage, and biomedicine. For example, in optics, nanoporous structures can be used to prepare photonic crystals, metasurfaces, and plasmon-enhanced substrates, enabling precise control of light propagation, absorption, and emission. In sensing, their high specific surface area and tunable porosity help enhance molecular adsorption and recognition capabilities, improving the sensitivity and response speed of gas, biological, and chemical sensors. Existing fabrication routes mainly focus on two approaches: one is template-guided chemical methods (soft / hard templates); the other is micro / nano fabrication methods involving "patterned polymers → high-temperature pyrolysis and carbonization" (represented by ultraviolet lithography).

[0003] Traditional template methods typically involve three main steps: First, a template agent (surfactant, self-assembled macromolecule, SiO2, Al2O3, porous oxides, etc.) that provides a nanoporous structure is mixed with a carbon-containing precursor (solution / sol). Then, the carbon-containing precursor is pyrolyzed under an inert atmosphere to generate a carbon framework. Finally, the porous carbon structure is obtained through chemical etching (acid / base / hydrofluoric acid, etc.) or dissolution. This method allows for precise tuning of porosity and pore size. However, it lacks high-resolution patterning capabilities and has poor compatibility with micro / nano fabrication.

[0004] Ultraviolet (UV) lithography typically involves two main steps: First, a photoresist is spin-coated and exposed / developed under UV light to obtain the target pattern. Then, high-temperature pyrolysis in an inert atmosphere transforms the polymer into a carbon material; a small number of pores spontaneously form during this process. This method is suitable for fabricating complex patterns and is compatible with micro / nano fabrication techniques. However, porosity and pore size are difficult to control independently, and high-temperature pyrolysis leads to dimensional distortion.

[0005] In summary, there is a fundamental contradiction between existing technologies in terms of "tunability of pore structure" and "high-precision patterning capability": chemical template method can adjust pores but cannot pattern them, photolithography pyrolysis method can pattern them but cannot control the pore structure, and generally relies on high-temperature carbonization process, making it difficult to balance structural integrity, resolution and mechanical properties.

[0006] Therefore, there is an urgent need for a low-temperature preparation method that simultaneously possesses controllable pore structure and nanoscale patterning capabilities to achieve high-fidelity, high-mechanical-strength, and designable nanoporous carbon structures, thereby promoting the practical application of nanoporous materials in fields such as optical micro / nano devices, high-sensitivity sensors, and lightweight mechanical structures. Summary of the Invention

[0007] This invention provides a method for fabricating patternable nanoporous structures with tunable pore structures based on ice lithography. Compared with traditional template methods and ultraviolet lithography, the fabrication method proposed in this invention can achieve 2D / 3D patterned fine structure design of nanoporous materials.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] A method for fabricating nanoporous structures based on ice etching includes: (1) mixing at least two gas sources in a mixing chamber in proportion to obtain a mixed gas; (2) forming an ice film of the mixed gas on a surface in a low-temperature environment; (3) performing electron beam exposure on the mixed gas ice film; heating up to remove the unexposed portion of the mixed ice film to obtain the nanoporous structure.

[0010] Using the method of this invention, both two-dimensional nanoporous structures can be fabricated, and three-dimensional nanoporous structures can be fabricated layer by layer. That is, by following the method in steps (1) to (3), the obtained nanoporous structure layers are fabricated layer by layer to finally obtain a three-dimensional nanoporous structure. When performing layer-by-layer fabrication, the thickness of each layer is determined by the material and the electron beam exposure capability. Similarly, by controlling the electron beam acceleration voltage, the thickness of the electron beam exposure can be achieved. By matching the layer thickness with the electron beam acceleration voltage, the fabrication of each layer can be realized.

[0011] Furthermore, a method for fabricating nanoporous structures based on ice etching includes: determining the gas source and its mixing ratio, the number of layers, the thickness of each ice film, and electron beam exposure parameters according to the structural characteristics of the nanoporous structure to be processed; depositing a mixed ice film according to the thickness of a single-layer nanoporous structure; processing layer by layer in sequence; for each layer, forming the structure in the following order: (i) first, mixing two gas sources in a mixing chamber in proportion; (ii) forming an ice film on the surface of an adjacent layer (or substrate); (iii) performing electron beam exposure on the mixed ice film; after processing, removing the unexposed portion of the mixed ice film by thermal development to obtain the nanoporous structure.

[0012] Furthermore, before processing, a patterning design is performed based on the target structure, and the electron beam exposure process described in step (3) is performed in the patterned area to obtain a 2D / 3D patterned nanoporous structure.

[0013] As a preferred embodiment, a nanoporous structure fabrication process based on ice etching includes the following steps:

[0014] (1) Place the planar substrate or non-planar sample to be processed into the vacuum sample chamber of the scanning electron microscope (SEM) and cool the sample to a low temperature (preferably below 130K);

[0015] (2) Mix organic molecular gas with water or oxide gas in a certain proportion;

[0016] (3) Inject the mixed gas and rapidly cool it on the sample surface to form a mixed ice film;

[0017] (4) Electron beam exposure of the mixed ice film causes changes in the material properties of the exposed area: the organic molecular gas ice film undergoes cross-linking and solidification, while the water or oxide gas ice film undergoes decomposition and vaporization.

[0018] (5) Repeat the above mixing (step (2)), injection (step (3)) and exposure steps (step (4)) according to the target structure design.

[0019] (6) Heat up until all remaining ice film material in unexposed areas is completely sublimated in a vacuum environment to obtain a finely patterned nanoporous structure.

[0020] Furthermore, the mixed gas includes: at least one substance A, which, after being exposed to an electron beam, can form a stable solid structure, and the unexposed portion can be liquefied or vaporized upon heating; and at least one substance B, which is a substance that can decompose / liquefy / vaporize upon being exposed to an electron beam or / and is unaffected by electron beam exposure or can be liquefied or vaporized upon heating.

[0021] For ease of operation, as a preferred option, the raw materials used for the ice film deposited in this invention are (A) substances that are solid / liquid / gas at room temperature, solid at low temperature, and can be transformed into a stable solid structure at room temperature after being irradiated by an electron beam, and the unexposed parts become liquid / gas after heating treatment; (B) substances that are solid / liquid / gas at room temperature, solid at low temperature, and can be decomposed / vaporized after being irradiated by an electron beam; or substances that are not affected by electron beam irradiation and become liquid / gas after heating.

[0022] Furthermore, the raw materials (gas source) used to form the ice film in this invention are divided into two categories: positive and negative, corresponding to the aforementioned substance A and substance B.

[0023] The determination of the raw materials for negative ice film mainly considers two factors: ① It is in a solid / liquid / gas state at room temperature (or other suitable temperatures) and in a solid state at low temperatures. ② The gas source is a precursor to the target material and will be converted into the target material under low-temperature electron beam irradiation. For example, if the target material for porous carbon is carbon, then a carbon-containing compound should be selected as the gas source (preferably anisole C7H8O).

[0024] Positive ice film raw materials should consider the following: ① They are in solid / liquid / gas state at room temperature and solid state at low temperature. ② They can decompose / vaporize after being irradiated by an electron beam.

[0025] Substance A includes one or more of ether compounds, aldehyde compounds, ketone compounds, alcohol compounds, carboxyl compounds, and hydrocarbon compounds; substance B includes one or more of water, carbon oxides (CO2, CO), nitrogen oxides (NO, NO2, N2O), and other oxides.

[0026] Furthermore, substance A is anisole, phenethyl ether, substituted phenyl ethers, other ethers, C3 or higher alkane alcohols, C4 or higher alkanes, etc. More preferably, the substance used to form the ice film includes one or more of anisole, phenethyl ether, substituted phenyl ethers, other ethers, C3-C20 alkane alcohols, and C4-C40 alkanes; substance B is one or more of water, CO2, CO, NO, NO2, and N2O.

[0027] Furthermore, substance A is one or more of the following liquid organic compounds (at room temperature): anisole, n-pentanol, octane, nonane, undecane, and tetradecane. Substance B is one or more of the following: water, CO2, and CO.

[0028] In this invention, the mixed gas source can be a mixture of two or more organic gases, water or other oxides.

[0029] The electron beam mask used in this invention is a hybrid ice film, unlike traditional photoresist. The method for removing the remaining mask in unexposed areas is heating-sublimation removal. The advantages of this development method are that it is fast, clean, and convenient. It does not require additional chemical cleaning agents; removal can be completed simply by controlling the substrate temperature, thus avoiding the introduction of chemical contamination.

[0030] In this invention, as a specific implementation, the gas used to form the ice film is introduced into the mixing chamber through a micro-leak valve and vacuum negative pressure. The intake volume and intake speed are monitored and controlled by installing a vacuum pressure gauge at the steam source. Combined with the vacuum pressure gauge at the mixing chamber, the mixing ratio of two or more gases is precisely controlled.

[0031] In this invention, the low-temperature range refers to the sublimation temperature of the raw material in its amorphous crystalline state under the corresponding pressure, or a temperature lower than the sublimation temperature of its amorphous crystalline state. Preferably, the low-temperature range is 20K-140K, and specific values ​​between these values. For example, for the formation of an amorphous ice film by anisole and water vapor, the low-temperature range is 120K-130K.

[0032] The surface on which the ice film forms can be a substrate surface or a pre-processed surface of the previous layer. The substrate can be a planar substrate (such as any one or more combinations of Au, Ag, Cu, Al, Pt, Pd, Mn, Fe, Co, Ni, Zn, Cd, Ge, Sn, Pb, Sb, Bi, Si, Ge, GaN, GaAs, GaP, ITO, InP, InAs, ZnS, ZnSe, CdS, CdSe, ZnO, TiO2, MgO, CdO, Al2O3, SiO2, or Si3N4), a non-planar substrate (such as the above-mentioned materials with non-flat surfaces, or fragile microstructures such as AFM probes, nanotubes and nanowires, fiber optic end faces, etc.), or the surface of the sample to be processed (planar or non-planar).

[0033] Preferably, the repetition of step (6) can theoretically be any number of times, up to the number of processing layers required for the desired nanoporous structure.

[0034] In this invention, the thickness of the hybrid ice film is measured using AFM at room temperature after the hybrid ice film has been cured by electron beam exposure. The thickness of a single-layer hybrid ice film ranges from 100 to 600 nm, and is more preferably 300 to 500 nm.

[0035] In this invention, the fabrication can be completed within the vacuum sample chamber of a scanning electron microscope. The scanning electron microscope is selected from one of thermal field emission scanning electron microscopy, cold field emission scanning electron microscopy, and environmental scanning electron microscopy. The entire nanoporous structure fabrication process is carried out within the sealed chamber of the scanning electron microscope.

[0036] In a mixed gas source, the ratio of the two gases is generally determined by the porosity of the target product. The gas that forms a stable solid structure after electron beam exposure is labeled A, and the other gas is labeled B. The volume ratio of the two gas sources is A:B = 1:1 to 10. For example, it could be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc. Further, the volume ratio of the two gas sources could be A:B = 1:2 to 5.

[0037] Using the method of this invention, the porosity of the product can be controlled by different electron beam exposure parameters. Appropriate electron beam exposure parameters need to be used according to the target nanoporous structure.

[0038] In this invention, the dose per unit area required for electron beam exposure is in the range of 0.1 mC / cm. 2 -10C / cm 2 Between. For example, it could be 0.2C / cm. 2 0.5C / cm 2 1C / cm 2 2C / cm 2 3C / cm 2 4C / cm 2 5C / cm 2 6C / cm 2 7C / cm 2 8C / cm 2 9C / cm 2 10C / cm 2 And the specific point values ​​between the above values, due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range. Preferably, it is 10 mC / cm. 2 -200mC / cm 2 The dose per unit area required for electron beam irradiation is related to the mechanical properties of the target product. Generally, the higher the dose per unit area required for electron beam irradiation, the more thorough the solidification of the material, and the greater the mechanical strength of the final target material.

[0039] In this invention, the electron beam energy range is between 1keV and 30keV. Examples include 2keV, 3keV, 4keV, 5keV, 6keV, 7keV, 8keV, 9keV, 10keV, 15keV, 20keV, 25keV, and 30keV, as well as specific values ​​within these ranges. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. Preferably, it is between 1keV and 10keV. The electron beam energy range corresponds to the thickness of each ice layer. In single-layer processing, it is only necessary to ensure penetration of the current layer; in multi-layer processing, in addition to ensuring penetration of the current layer, it is also necessary to ensure that it does not affect the structure of adjacent already processed layers.

[0040] In this invention, when an electron beam exposes a certain ice layer, it has no effect on the previously processed layers. For example, the exposure of the second ice film by the electron beam has no effect on the first ice film. This process achieves this by precisely controlling the electron beam acceleration voltage, ensuring that the maximum penetration depth of the electrons at that voltage matches the thickness of the ice film, thereby avoiding exposure of the first ice film.

[0041] In this invention, EDS / XPS / Raman analysis of the electron beam exposure region of the mixed ice film confirmed that the obtained nanoporous structure is amorphous carbon with high purity, and its carbon content is higher than 85%.

[0042] In this invention, when preparing the ice film, the corresponding gas injection system (GIS) can be one or more; the latter is used to simultaneously introduce water vapor source, organic vapor source and mixed vapor source respectively.

[0043] The processing technology proposed in this invention can produce nanoporous structures with adjustable porosity and pore size, and 2D / 3D patterned structures.

[0044] A nanoporous structure is obtained by the processing method described in any of the above technical solutions.

[0045] In this invention, after the hybrid ice film is cured by electron beam exposure, its pore size diameter ranges from sub-10nm to 300nm as observed by SEM, and its porosity ranges from 0-77% as calculated by the effective medium approximation (EMA) method.

[0046] This invention, based on ice etching technology, represents a novel micro / nano fabrication method belonging to the category of additive manufacturing. The method described herein can fabricate high-precision patterned porous nanostructures with sub-micron accuracy. From mixing a gas and injecting it onto a low-temperature cooled sample surface, to sublimating the unexposed mixed ice film on the sample surface through heating, the entire process is environmentally friendly and achieved in a single, one-step process, demonstrating promising application prospects. Attached Figure Description

[0047] Figure 1 is a schematic flowchart of the nanoporous structure processing method of the present invention;

[0048] Figure 2 shows the single-layer nanoporous film fabricated by the method of the present invention;

[0049] Figure 3 shows a two-dimensional patterned nanoporous structure with a “PAINT” pattern fabricated by the method of the present invention;

[0050] Figure 4 shows the three-dimensional patterned nanoporous structure with a "waffle" morphology produced by the method of the present invention.

[0051] Figure 5 shows the nanoporous structure with varying porosity produced by the method of the present invention using a variable dosage.

[0052] Figure 6 shows the mechanical parameters of nanoporous carbon obtained under different exposure parameters. Detailed Implementation

[0053] For ease of understanding, the present invention is illustrated below with examples. Those skilled in the art will understand that the following examples are merely preferred embodiments of the present invention and are intended only to aid in understanding the invention; therefore, they should not be considered as limiting the scope of the invention.

[0054] Figure 1 shows a schematic flowchart of the nanoporous carbon processing method of the present invention. The flowchart takes the processing of a single-layer thin film containing a nanoporous structure as an example, and specifically includes: gas mixing, mixed ice film deposition, electron beam exposure, and sublimation removal of the remaining ice film.

[0055] (1) Gas mixing: The total amount of gas entering the mixing chamber is precisely adjusted using a micro-leak valve and mixed according to a preset ratio.

[0056] (2) Mixed ice film deposition: Mixed gases (including organic molecular gases and water vapor or other oxide gases) condense on a pre-cooled substrate to form an amorphous ice film.

[0057] (3) Electron beam exposure: The organic molecular components in the mixed ice film in the exposed area are solidified into a non-volatile material, forming a porous framework; the exposed water ice or other oxide components decompose and form pores.

[0058] (4) Heating and sublimation: The sample is restored to room temperature, the remaining unexposed ice film sublimates, while the porous framework solidified in the exposed area is preserved, resulting in a nanoporous structure.

[0059] Example 1: Single-layer nanoporous film

[0060] A single-layer nanoporous film, as shown in Figure 2, was fabricated using a water vapor / anisole gas volume ratio of 3:1. The deposited mixed ice film was approximately 500 nm thick and was prepared via 5 keV electron beam exposure at a beam current of 0.32 nA. The dose per unit area was 80 mC / cm². 2 The exposed area is a 20µm x 20µm square. The substrate was then heated to room temperature to remove the remaining ice layer, resulting in a single-layer nanoporous film as shown in the figure.

[0061] Figure 2 shows SEM images of the thin film with a nanoporous structure. In Figure 2, the scale bar of a is 2 μm, and the scale bar of b is 400 nm.

[0062] Example 2: Two-dimensional patterned nanoporous structure with a “PAINT” pattern

[0063] A two-dimensional patterned nanoporous structure with a "PAINT" pattern, as shown in Figure 3, was fabricated. The water vapor / anisole gas volume ratio was 3:1, and a mixed ice film thickness of approximately 300 nm was deposited. The coordinates and path information of the area to be exposed were obtained using image processing software. A specific area was exposed using a 5 keV electron beam with an electron beam current of 0.32 nA, and a dose per unit area of ​​60 mC / cm². 2 After exposure, the substrate was brought back to room temperature to remove the ice layer in the unexposed areas, resulting in a two-dimensional patterned nanoporous structure with a "PAINT" pattern.

[0064] Figure 3 shows SEM images of a two-dimensional patterned nanoporous structure with a "PAINT" pattern. As shown in Figure 3a, the hybrid ice film can be patterned using an electron beam, and the overall structure has clear edges. Figure 3b shows that the patterned structure has a nanoporous microstructure. The scale bar in Figure 3a is 5 μm, and the scale bar in Figure 3b is 200 nm.

[0065] Example 3: Three-dimensional patterned nanoporous structure with a "waffle" morphology

[0066] When using the sample to design 3D nanoporous structures, it is necessary to pre-mark it for sample surface positioning and electron beam focusing, as well as for precise alignment during subsequent multilayer deposition and exposure processes.

[0067] Figure 4 shows the SEM image of the fabricated three-dimensional patterned nanoporous structure with a "waffle" morphology. The first layer of the mixed ice film used a water vapor / anisole gas volume ratio of 3:1, while the remaining layers used a ratio of 3.5:1. Each layer was approximately 300 nm thick. Exposure was performed using a 5 keV electron beam with a beam current of 0.32 nA and a dose per unit area of ​​80 mC / cm². 2 The single-layer exposure area is a rectangular array with dimensions of 20 μm x 2 μm. The substrate was then heated to room temperature to remove the remaining ice layer, resulting in a three-dimensional patterned nanoporous structure with a "waffle" morphology, as shown in Figure 4. In Figure 4a, the scale bar is 2 μm, and in Figure 4b, it is 100 nm.

[0068] Example 4: Nanoporous structures with varying porosity due to different dosages

[0069] Figure 5 illustrates the variable porosity nanoporous structure achieved through exposure dose modulation. The water vapor / anisole gas volume ratio used was 3:1, the deposited mixed ice film thickness was approximately 300 nm, and exposure was performed using a 5 keV electron beam with an electron beam current of 0.32 nA. The doses per unit area used were 30 / 40 / 50 / 60 / 70 / 80 mC / cm². 2 These correspond to a~f in Figure 5, respectively. The exposed area is a 5um*5um square. Subsequently, the substrate was heated to room temperature to remove the remaining ice layer, resulting in a variable porosity nanoporous structure as shown in the figure.

[0070] Figure 5 shows SEM images of nanoporous structures with different porosities. As can be seen from Figure 5a, the mixed ice film, when subjected to a low dose (dose per unit area of ​​30 mC / cm²), exhibits [the following effect / effect]: 2During electron beam exposure, no obvious porous structure was generated. As shown in Figure 5 (bf), the porosity of the resulting nanoporous structure increases with increasing electron dose. This process allows for precise control of the product's porosity by adjusting the electron dose, thus enabling free porosity adjustment. The scale bars in Figure 5 are all 100 nm.

[0071] Figure 6 shows the different exposure parameters (in a: dose per unit area is 30 / 40 / 50 / 60 / 70 mC / cm). 2 In b: the dose per unit area is 30 / 40 / 50 / 60 / 70 / 80 / 90 mC / cm. 2 The mechanical parameters of the nanoporous carbon obtained by the present invention are shown in Figure 6. Compression tests using a nanoindenter show that the Young's modulus of the nanoporous carbon processed by the method of this invention can be controlled within the range of 20 MPa to 170 MPa by adjusting the electron dose used during exposure. Figure 6 also demonstrates another significant advantage of this invention: the method of this invention can produce nanoporous structures with tunable mechanical properties, a feature not found in other nanoporous carbon processing methods.

[0072] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0073] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0074] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for fabricating nanoporous structures based on ice etching, characterized in that, include: (1) Mix at least two gaseous substances in a mixing chamber in proportion to obtain a mixed gas; (2) Form an ice film of the mixed gas on a surface in a low temperature environment; (3) Expose the mixed gas ice film with an electron beam; heat up to remove the unexposed part of the mixed ice film to obtain the nanoporous structure.

2. The method for fabricating nanoporous structures based on ice etching according to claim 1, characterized in that, The mixed gas includes: at least one substance A, which, after being exposed to an electron beam, can form a stable solid structure, and the unexposed portion can be liquefied or vaporized upon heating; and at least one substance B, which is a substance that can decompose / liquefy / vaporize upon being exposed to an electron beam or / and a substance that can be liquefied or vaporized upon heating.

3. The method for fabricating nanoporous structures based on ice etching according to claim 2, characterized in that, Substance A is one or more of the following: ether compounds, aldehyde compounds, ketone compounds, alcohol compounds, carboxyl compounds, and hydrocarbon compounds; Substance B is one or more of the following: water, carbon oxides, nitrogen oxides, and other oxides.

4. The method for fabricating nanoporous structures based on ice etching according to claim 3, characterized in that, Substance A is one or more of anisole, phenethyl ether, C3-C20 alkane alcohols, and C4-C40 alkanes; Substance B is one or more of water, CO2, CO, NO, NO2, and N2O.

5. The method for fabricating nanoporous structures based on ice etching according to claim 2, characterized in that, In the mixed gas source, the volume ratio of substance A to substance B is A:B = 1:(1~10).

6. The method for fabricating nanoporous structures based on ice etching according to claim 1, characterized in that, The low temperature range is 20K-140K.

7. The method for fabricating nanoporous structures based on ice etching according to claim 1, characterized in that, The required dose per unit area for electron beam exposure is in the range of 0.1 mC / cm². 2 -10C / cm 2 Between; the electron beam energy ranges from 1keV to 30keV.

8. The method for fabricating nanoporous structures based on ice etching according to claim 1, characterized in that, The low temperature range is 120K-130K; the volume ratio of substance A and substance B in the mixed gas is A:B=1:(2~5); the dose per unit area required for electron beam exposure is 10mC / cm². 2 -200mC / cm 2 The electron beam energy is 1keV-10keV.

9. The method for fabricating nanoporous structures based on ice etching according to claim 1, characterized in that, Before processing, a pattern design is carried out according to the target structure, and the electron beam exposure process described in step (3) is performed in the pattern area.

10. The method for fabricating nanoporous structures based on ice etching according to any one of claims 1 to 9, characterized in that, The three-dimensional nanoporous structure is finally obtained by processing layer by layer according to the method of steps (1) to (3).

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