A method for manufacturing a large-area atomic-level structure mold and device on a free-form surface

Abstract

The application discloses a manufacturing method of a large-area atomic-level hierarchical structure device on a free-form surface, which comprises the following steps: coating, photoetching, film plating, electroforming, metal mold demolding, nano-imprinting, metal sheet demolding, anodic oxidation, atomic layer deposition, pouring and polymer film demolding. The photoresist is coated on the surface of the free-form substrate, and the photoetching step is performed, so that the patterned concave surface structure is obtained. The patterned surface is metallized by film plating, and then the electroforming replication process step is performed, so that the convex metal mold is obtained by demolding. Then, the nano-imprinting of the metal sheet is performed by taking the metal mold as a template, so that the structure transfer is realized. The hierarchical nano-structure is formed by anodic oxidation on the structured metal sheet, and the nano-structure is filled to the atomic size by atomic layer deposition. Finally, the polymer pouring process is performed by taking the atomic-level metal sheet as a template, so that the large-area atomic-level hierarchical structure device on the free-form surface is obtained by demolding. The application provides a precise manufacturing method.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano manufacturing and semiconductor processing technology, and in particular relates to a method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface. Background Technology

[0002] With the rapid development of micro / nanotechnology and microelectromechanical systems (MEMS) technology, the applications of micro / nano structures in optoelectronic devices, gene sequencing, and optical imaging are attracting increasing attention. In particular, many devices or systems require the construction of functional structures on curved or non-planar surfaces. The precision and complexity of these structures need to be precisely controlled at the atomic scale to meet specific functional requirements. From optical components to biomedical sensors, atomic-scale fabrication on curved surfaces can alter the optical, electrical, and mechanical properties of devices, bringing innovation to multiple fields such as optoelectronics, biomedicine, and mechanical engineering. Furthermore, curved surface design can optimize device performance, such as improving the transmittance or reflectance of optical devices, and enabling better utilization of limited space, especially in micro and nanodevices. Therefore, atomic-scale fabrication on curved surfaces is of great significance in today's technological development.

[0003] However, fabrication on free-form surfaces is a challenging task. The diverse and complex shapes of surface structures make precise control at the atomic scale exceptionally difficult. Furthermore, the local curvature, unevenness, and three-dimensional morphology of the surface further complicate manufacturing. Traditional planar micro / nano fabrication techniques are difficult to apply directly to curved structures, and also struggle to meet the demands of atomic-scale fabrication on curved surfaces. Therefore, fabrication of free-form surfaces requires specialized processes and technologies, particularly in the preparation of large-area, atomically hierarchical structure molds and devices.

[0004] Based on existing micro / nano fabrication technologies, it is virtually impossible to fabricate atomic-scale structures on curved surfaces using a single process. Therefore, exploring new manufacturing methods is urgently needed. Anodizing is a fabrication method that forms porous nanostructures through self-assembly. The shape and size of these nanostructures can be flexibly controlled according to the anodizing process, with pore sizes ranging from a few nanometers to micrometers. For atomic-scale fabrication, common techniques utilize atomic layer deposition (ALD) and chemical vapor deposition (CVD) to deposit materials layer by layer with precise control at the molecular level. Furthermore, with technological advancements, photolithography has continuously developed, enabling the creation of increasingly smaller feature sizes. In recent years, advanced manufacturing processes, such as those using extreme ultraviolet (EUV) lithography, have achieved structural dimensions approaching or even smaller than 3 nanometers. Electroforming technology offers atomic-level surface replication precision and can be used to fabricate metal parts or molds with fine structures and high precision. By combining these precision micro / nano structure fabrication methods, it becomes possible to fabricate large-area atomic-level hierarchical structures on free-form surfaces. Summary of the Invention

[0005] This invention provides a method for manufacturing large-area atomic-level hierarchical structure molds and devices on free-form surfaces, aiming to break through the current micro-nano manufacturing scale, and to provide a micro-nano processing method on curved surfaces, combined with methods such as anodizing to obtain atomic-level hierarchical structure molds and devices.

[0006] The present invention provides a method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized by comprising the following steps in sequence:

[0007] (1) Applying adhesive;

[0008] Aluminum is precisely cut using ultra-precision laser cutting to obtain a free-form aluminum substrate, and a photoresist layer with a thickness of about tens of nanometers is uniformly coated on the aluminum substrate.

[0009] (2) Photolithography steps;

[0010] After the photoresist is dried and cured, it is exposed to ultraviolet light / electron beam to prepare nanoscale patterns. After baking, developing and shaping, a photoresist pattern structure with nanoscale pits is obtained on an aluminum sheet. The specific structure size depends on the photolithography process capability, ranging from a few nanometers to several hundred nanometers.

[0011] (3) Coating steps;

[0012] A nanometer-thick metal conductive film is deposited on the surface of a concave photoresist pattern structure using chemical vapor deposition / physical vapor deposition methods. The thickness of the nanometer layer depends on the size of the structure after photolithography, ranging from about one micrometer to several micrometers.

[0013] (4) Electroforming steps;

[0014] Electroforming is performed on the pattern structure after the conductive film is deposited to accurately replicate the photoresist pattern by electrodeposition, resulting in a convex nickel mold with nanoscale feature size and a thickness of hundreds of micrometers.

[0015] (5) Demolding steps for metal molds;

[0016] The convex nickel mold and the aluminum substrate were etched using hydrofluoric acid / sodium hydroxide until the aluminum substrate was completely removed, leaving the convex nickel mold with the desired nanoscale feature size.

[0017] (6) Nanoimprinting steps;

[0018] A molecular coating is applied to the convex nickel mold to ensure that the nanoscale feature structure retains its shape during the demolding process. Then, using nanoimprinting technology, the pattern structure on the convex nickel mold is transferred to an aluminum sheet, with the convex nickel mold as a template.

[0019] (7) Demolding steps for aluminum sheets;

[0020] The aluminum sheet obtained by embossing is cleaned to obtain an aluminum sheet with a concave nanostructure.

[0021] (8) Anodizing step;

[0022] Anodizing aluminum sheets with concave nanostructures yields hierarchical nanoarray structures with different sizes.

[0023] (9) Atomic layer deposition steps;

[0024] Atomic layer deposition technology is used to deposit a metal thin film with a controllable single-atom layer thickness on the surface of the hierarchical nanoarray structure, and the gaps between the nanoarray structures are closed as much as possible to the atomic and near-atomic scale, resulting in an aluminum-based mold with an atomic-level hierarchical structure on a free-form surface.

[0025] (10) Pouring steps;

[0026] Using polymers to cast atomic-level hierarchical aluminum-based molds, the atomic-level hierarchical structure on the aluminum-based molds is copied and transferred to the polymer material.

[0027] (11) Polymer film demolding step;

[0028] After the polymer has fully cured, the polymer and aluminum mold are demolded and cleaned to obtain a convex polymer thin film device with a hierarchical structure at the atomic and near-atomic scale.

[0029] A method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized in that the photoresist needs to have high resolution and precise thickness control capabilities, and the aluminum substrate needs to be cleaned and treated before applying the photoresist to ensure stable adhesion of the photoresist layer.

[0030] A method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized in that the conductive film can be a material with good conductivity and a certain adhesion ability to ensure its durability and stability, such as copper, chromium, gold, etc.

[0031] A method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized in that the specific size of the nanostructure on the metal convex mold is determined by the photolithography process level.

[0032] A method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized in that the thickness of the convex nickel mold with nanoscale features is precisely controlled by the electroforming process conditions.

[0033] A method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized in that the specific size of the nanopores is determined by the anodizing process conditions, which can be adjusted by conditions such as the anodizing electrolyte, voltage, and temperature.

[0034] A method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface, characterized in that the atomic layer deposition needs to be controlled with atomic-level precision to provide the required film thickness and a certain conductivity, and the metal film material can be chromium, copper, platinum, etc.

[0035] A method for manufacturing a mold and device with a large area atomic-level hierarchical structure on a free-form surface, characterized in that the polymer is selected from a specific polymer material with high hardness and stability to ensure that no deformation or damage occurs during the subsequent imprinting process.

[0036] The significant advantages of this invention are:

[0037] (1) By combining advanced processing technology and nano-manufacturing processes, the complexity of curved surface shapes can be overcome, enabling precise control and processing of free-form surfaces. Whether it is a curved, uneven surface or a structure with large curvature changes, it is possible to achieve fine atomic-level processing, expanding the applicability of atomic-level manufacturing.

[0038] (2) It breaks through the scale limit of a single manufacturing method and does not require the use of specialized atomic manufacturing equipment.

[0039] (3) Compared with traditional manufacturing methods, this method combines common processes such as photolithography, coating, electroforming, atomic layer deposition, and anodizing, and can achieve precise machining of free-form surfaces. Such a combination of processes means lower manufacturing costs, and the resulting atomic-level structured metal molds and polymer devices are suitable for large-scale mass production while maintaining high precision and complexity. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the manufacturing process for a large-area atomic-level hierarchical structure mold and device on a free-form surface.

[0041] In the figure: 1. Freeform aluminum substrate; 2. Photoresist; 3. Concave nanostructure surface; 4. Conductive metal thin film; 5. Convex nickel metal mold; 6. Concave aluminum sheet mold; 7. Concave nano-layer structure aluminum sheet mold; 8. Atomic layer metal thin film; 9. Convex atomic-layer polymer thin film device. Detailed Implementation

[0042] The specific embodiments of this invention patent are described in detail below with reference to the technical solution and accompanying drawings.

[0043] The present invention provides a specific embodiment of a method for manufacturing atomic-level layered polymethyl methacrylate molds and devices on free-form surfaces.

[0044] Example 1, the manufacturing method of which follows these steps:

[0045] (1) Applying adhesive;

[0046] First, clean the aluminum surface with isopropanol or acetone to ensure it is free of dust and oil. Then, use a spin coater to evenly coat the photoresist onto the aluminum substrate surface, to a thickness of approximately tens of nanometers. Next, bake the photoresist at a preset temperature to cure it.

[0047] (2) Photolithography steps;

[0048] The photoresist surface was treated with electron beam exposure, and after development and setting, the aluminum wafer was cleaned to obtain... Figure 1 (b) shows the nanoscale microstructure;

[0049] (3) Coating steps;

[0050] The sample was placed in the vacuum chamber of a PVD (Physical Vapor Deposition) apparatus and heated to enhance surface activity. Then, metallic chromium was sputtered and deposited onto the sample surface via thermal evaporation or sputtering to form a conductive thin film, which served as the conductive layer for electroforming.

[0051] (4) Electroforming steps;

[0052] After the above-mentioned coated structure is activated with aminosulfonic acid, it is then subjected to nickel electroforming. During the nanostructure electrodeposition and filling stage, an A / dm² ratio of less than 0.01 is used. 2 The pulsed current density was adjusted to precisely replicate the photoresist pattern onto the nickel mold. Once the nanostructure was filled, the pulsed current density was increased to 1 A / dm². 2 The current density was used to electrodeposit and thicken the nickel mold substrate to a thickness of several hundred micrometers.

[0053] (5) Demolding steps for metal molds;

[0054] The bonding of the aluminum substrate and the nickel mold obtained after electroforming was performed using 2% hydrofluoric acid. Figure 1 (d) Etching is performed at a temperature maintained at 30°C to chemically etch the aluminum substrate. After demolding, the sample is removed and thoroughly cleaned with water or sodium bicarbonate solution to remove residual acidic solution and any other impurities, resulting in a nickel nanostructure mold with raised structures, such as... Figure 1 As shown in (e);

[0055] (6) Nanoimprinting steps;

[0056] To prevent deformation and distortion of the fine structure during demolding, a BGL-GZ-83 molecular film was pre-deposited onto the surface of the nickel concave mold using evaporation to facilitate non-destructive demolding between the mold and the polymer. Eight hours later, using the nickel concave mold as a template, the pattern structure of the nickel convex mold was transferred onto an aluminum sheet substrate using nanoimprint technology.

[0057] (7) Demolding steps for aluminum sheets;

[0058] The aluminum sheet mold with convex microstructure obtained by nanoimprinting is demolded and cleaned thoroughly (e.g. Figure 1 (g));

[0059] (8) Anodizing step;

[0060] The aluminum sheet mold obtained above is subjected to anodizing treatment. Different anodizing conditions are used for different aperture requirements.

[0061] Specifically, if a pore size structure of several nanometers to tens of nanometers is required, the aluminum sheet can be anodized for 10 minutes in a 20 wt.% H2SO4 solution using a voltage of 25V at 1℃. Then, after cleaning, it can be immersed in a mixed solution of 6 wt.% H3PO4 and 1.8 wt.% H2CrO4 at 60℃ for 15 minutes. Finally, after cleaning, it can be anodized in a 20 wt.% H2SO4 solution for 45-870 minutes.

[0062] Specifically, if a pore size structure of tens to hundreds of nanometers is required, the aluminum sheet can be anodized for 12 hours in a mixed solution of 0.4M H2CrO4 and 0.6M H2SO4 using a voltage of 15-55V at 0℃. After cleaning, it can be soaked in a mixed solution of 6wt.% H3PO4 and 1.8wt.% H2CrO4 at 60℃ for 90 minutes. Finally, after cleaning, it can be anodized for 12 hours in a mixed solution of 0.4M H2CrO4 and 0.6M H2SO4.

[0063] Specifically, if a pore size of several hundred nanometers is required, the aluminum sheet can be anodized for 200 seconds in a 2wt.% H3PO4 solution using a voltage of 40-120V at 10°C. After cleaning, it can be soaked in a 5wt.% H3PO4 solution at 30°C for 12.5 minutes. These two steps can be repeated 5 times.

[0064] (9) Atomic layer deposition steps;

[0065] Patterns with nanoscale hierarchical structures after anodizing ( Figure 1 (h) Atomic layer deposition is performed to deposit isotropic chromium films with atomically controllable thickness layer by layer on the surface, so that the nanoarray structure obtained by anodizing can be minimized to the atomic scale (e.g., Figure 1 (i));

[0066] (10) Pouring steps;

[0067] The pre-prepared PMMA (polymethyl methacrylate) solution is poured evenly into the mold frame, covering the entire atomic-level aluminum mold surface to achieve the required thickness of hundreds of micrometers. Ensure the PMMA liquid is evenly distributed and fills the mold frame, then expose it to ultraviolet light to cure.

[0068] (11) Polymer film demolding step;

[0069] The PMMA film is mechanically demolded from the aluminum mold and cleaned to obtain a polymer device with an atomic-level hierarchical structure.

[0070] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Any equivalent process flow utilizing the present invention and the accompanying drawings, or any direct or indirect application in other technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for fabricating a mold and a device of large-area atomic-level structure on a free-form surface, characterized in that, The sequence comprises the following steps: (1) a gluing step; precise cutting of aluminum by ultra-precision laser cutting processing to obtain a free-form curved aluminum substrate, and uniform coating of a photoresist layer on the aluminum substrate; (2) a photoetching step; after drying and curing of the photoresist, nanoscale patterns are prepared by UV / electron beam exposure treatment, and after post-baking and development, a photoresist pattern structure with nanoscale pits is obtained on the aluminum sheet, with a structure size of several nanometers to several hundred nanometers; (3) a film plating step; a layer of metal conductive film with a thickness of one to several microns is deposited on the surface of the concave photoresist pattern structure by chemical vapor deposition / physical vapor deposition method; (4) an electroforming step; the pattern structure after plating of the conductive film is electroformed to accurately copy the photoresist pattern, and a convex metal nickel mold with nanoscale feature size and a thickness of several hundred microns is obtained; (5) a metal mold demolding step; the combination of the convex metal nickel mold and the aluminum substrate is etched by hydrofluoric acid / sodium hydroxide until the aluminum substrate is completely removed, leaving the convex metal nickel mold with the required nanoscale features; (6) a nanoimprinting step; the convex metal nickel mold is subjected to molecular coating treatment to ensure that the nanoscale feature structure maintains its shape during demolding, and then nanoimprinting technology is used to transfer the pattern structure on the convex metal nickel mold to an aluminum sheet using the convex metal nickel mold as a template; (7) an aluminum sheet demolding step; the aluminum sheet obtained by imprinting is cleaned to obtain an aluminum sheet with a concave nanostructure; (8) an anodizing step; the aluminum sheet with a concave nanostructure is subjected to an anodizing process to obtain a hierarchical nanoarray structure with different sizes of nanoscale gaps; (9) an atomic layer deposition step; a metal thin film with a single atomic layer thickness is deposited on the surface of the hierarchical nanoarray structure using atomic layer deposition technology, the nanoscale array structure gaps are filled to the atomic and near-atomic scale, and an aluminum-based mold with an atomic-level hierarchical structure on a free-form surface is obtained; (10) a casting step; a polymer is used to cast the atomic-level hierarchical structure aluminum-based mold to copy the atomic-level hierarchical structure on the aluminum-based mold to a polymer material; (11) a polymer film demolding step; after the polymer is completely cured, the polymer and the aluminum mold are demolded and cleaned to obtain a hierarchical structure convex polymer film device with atomic and near-atomic scale.

2. The method of claim 1, wherein the mold and the device are formed on a free surface.

2. The method of claim 1, wherein the mold and the device are formed on a free surface. The photoresist in step (1) needs to have high resolution and precise thickness control capability, and the aluminum substrate needs to be cleaned and treated before gluing to ensure stable adhesion of the glue layer.

3. The method of claim 1, wherein the mold and the device are formed on a free surface.

3. The method of claim 1, wherein the mold and the device are formed on a free surface. The conductive film in step (3) is copper, chromium or gold with conductive properties and certain adhesion ability.

4. The method of claim 1, wherein the mold and the device are formed on a free surface. 5 1 The specific size of the nanostructure on the convex metal nickel mold in step (4) is determined by the photoetching process level.

5. The method of claim 1, wherein the mold and the device are formed on a free surface.

5. The method of claim 1, wherein the mold and the device are formed on a free surface. The thickness of the convex nickel mold with nanoscale features in step (5) is precisely controlled by the electroforming process conditions.

6. The method of claim 1, wherein the mold and the device are formed on a freeform surface. 5 The specific size of the nanopores in step (8) is determined by the anodizing process conditions, which are adjusted by the anodizing electrolyte, voltage size and temperature conditions.

7. The method of claim 1, wherein the mold and the device are formed on a free surface. The atomic layer deposition in the step (9) needs to control the deposition with atomic layer precision, to provide the required film thickness and certain conductivity, and the metal film material is chromium, copper and platinum. ​ 8. The method for manufacturing a large-area atomic-level hierarchical structure mold and device on a free-form surface as described in claim 1, characterized in that, The specific polymer material with high hardness and stability is selected in the step (10) to ensure that no deformation and damage occur in the subsequent embossing process.

Images