A method for preparing a nanoimprint hard mold

Abstract

The present disclosure discloses a method for preparing a nanoimprint die. The method includes: providing an imprint sheet having an adhesive layer, the adhesive layer forming first grating grooves, the first grating grooves forming a predetermined pattern; modifying the first grating grooves to form modified grooves, the modified grooves having a width greater than the width of the first grating grooves and a depth equal to the depth of the first grating grooves; and coating the modified grooves with a thin film layer to form second grating grooves, the hardness of the thin film layer being greater than the hardness of the adhesive layer, the second grating grooves having the same dimensions as the first grating grooves, and the second grating grooves forming the predetermined pattern.

Description

Technical Field

[0001] The present invention relates to the technical field of diffraction grating preparation, and more particularly to a method for preparing a nanoimprint hard mold. Background Art

[0002] A diffraction grating is a type of grating. Through its regular structure, it causes the amplitude or phase (or both) of the incident light to be periodically spatially modulated. The diffraction grating used in actual applications is usually a flat plate with grooves or indentations on the surface. Among them, the grooves or indentations can be produced by nanoimprinting technology. At present, nanoimprinting processing technology has replaced traditional mechanical methods and become the main means of processing gratings. The current mainstream nanoimprinting solution is the UV soft film imprinting solution, in which the hard mold is the master mold for nanoimprinting. After multiple imprinting, the performance and structure of the hard mold will be damaged and need to be replaced frequently. However, the production of a new hard mold is relatively complicated and requires electron beam exposure, development and etching, with low yield, long time consumption and high cost.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the Invention

[0004] One object of the present invention is to provide a new technical solution for the preparation method of a nanoimprint hard mold.

[0005] According to one aspect of the present invention, a method for preparing a nanoimprint die is provided. The method comprises: providing an imprint sheet having an adhesive layer, the adhesive layer being formed with first grating grooves, the first grating grooves forming a predetermined pattern;

[0006] Modifying the first grating groove to form a modified groove, wherein the width of the modified groove is greater than the width of the first grating groove, and the depth of the modified groove is equal to the depth of the first grating groove;

[0007] A thin film layer is plated on the modified groove to form a second grating groove. The hardness of the thin film layer is greater than that of the glue layer. The size of the second grating groove is the same as that of the first grating groove. The second grating groove forms the set texture.

[0008] Optionally, the adhesive layer is made of UV nano-imprint adhesive.

[0009] Optionally, modifying the first grating grooves to form modified grooves includes:

[0010] The first grating grooves are modified by a reactive ion beam etching process.

[0011] Optionally, the first grating groove is modified to form a modified groove.

[0012] The ratio of the width of the modified groove to the width of the first grating groove is 1.2:1 to 1.5:1.

[0013] Optionally, the step of coating a thin film layer on the modified groove to form a second grating groove comprises:

[0014] A thin film layer is deposited on the modified groove by an atomic layer thin film deposition process.

[0015] Optionally, the material of the thin film layer is silicon dioxide or titanium dioxide.

[0016] Optionally, after coating a thin film layer on the modified groove to form a second grating groove, the method further comprises:

[0017] The film layer is subjected to surface activation treatment.

[0018] Optionally, the thin film layer is subjected to surface activation treatment by a plasma cleaning process.

[0019] Optionally, after the film layer is subjected to surface activation treatment, the method further comprises:

[0020] An anti-stick layer is coated on the film layer.

[0021] Optionally, the material of the anti-sticking layer is a fluorine-containing low surface energy organic compound.

[0022] In the disclosed embodiments, by etching the grating grooves on the adhesive layer of an existing stamping sheet and coating it with a thin film layer, the stamping sheet can be modified into a new hard mold that meets the required hardness. This effectively improves the production efficiency and yield of the hard mold and avoids the inconvenience of having to go through a complex process to produce a new hard mold. Furthermore, the existing stamping sheet is low-cost, and using it to improve the new hard mold can reduce the manufacturing cost of the hard mold.

[0023] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0025] Figure 1 4 is a flow chart of a method for preparing a nanoimprint hard mold according to an embodiment of the present disclosure.

[0026] Figure 2 is a schematic diagram of an embossed sheet according to an embodiment of the present disclosure.

[0027] Figure 3 Schematic diagram of a modified tank according to an embodiment of the present disclosure.

[0028] Figure 4 Schematic diagram of a thin film layer according to an embodiment of the present disclosure.

[0029] Figure 5 Schematic diagram of an anti-sticking layer according to an embodiment of the present disclosure.

[0030] 1. Embossed sheet; 2. Adhesive layer; 3. First grating groove; 4. Modified groove; 5. Thin film layer; 6. Second grating groove; 7. Anti-sticking layer. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0033] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0034] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0035] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] According to one embodiment of the present disclosure, a method for preparing a nanoimprint hard mold is provided. Figure 1 As shown, the method includes:

[0037] An embossing sheet 1 is provided. The embossing sheet 1 has a glue layer 2. The glue layer 2 is formed with first grating grooves 3. The first grating grooves 3 form a predetermined pattern.

[0038] The first grating groove 3 is modified to form a modified groove 4. The width of the modified groove 4 is greater than the width of the first grating groove 3. The depth of the modified groove 4 is equal to the depth of the first grating groove 3.

[0039] A thin film layer 5 is deposited on the modified grooves 4 to form second grating grooves 6. The hardness of the thin film layer 5 is greater than that of the adhesive layer 2. The dimensions of the second grating grooves 6 are the same as those of the first grating grooves 3. The second grating grooves 6 form a predetermined pattern.

[0040] It's important to note that the nanoimprint process involves three components: a hard mold, a soft mold, and the product. Typically, the texture structure on the soft mold mirrors that of the hard mold. The user can transfer the texture structure from the hard mold to the product using the soft mold. However, repeated imprinting or accidental damage to the hard mold can degrade its performance and structure.

[0041] In this embodiment, the stamping sheet 1 is the product described above. Since the stamping sheet 1 has a low production cost, the stamping sheet 1 is improved to obtain a new hard mold, which can significantly reduce the production cost of the hard mold.

[0042] In addition, the adhesive layer 2 of the embossing sheet 1 is modified and coated with a thin film layer 5 to obtain a hard mold that meets the hardness requirements, which can reduce the difficulty of hard mold production, avoid the original complex process of hard mold production, and improve the production efficiency of the hard mold.

[0043] In this embodiment, if Figure 2 As shown, the embossing sheet 1 has an adhesive layer 2. The adhesive layer 2 is formed with first grating grooves 3. These first grating grooves 3 form a predetermined pattern. It should be noted that the predetermined pattern of the first grating grooves 3 formed on the embossing sheet 1 is identical to the predetermined pattern on the die. In other words, the predetermined pattern of the first grating grooves 3 formed on the original embossing sheet 1 is identical to the predetermined pattern on the die, with precise accuracy.

[0044] like Figure 3 As shown, the first grating groove 3 is modified to form a modified groove 4. The width of the modified groove 4 is greater than the width of the first grating groove 3. The depth of the modified groove 4 is equal to the depth of the first grating groove 3. Figure 4 As shown, a thin film layer 5 is plated on the modified groove 4 to form a second grating groove 6. The size of the second grating groove 6 is the same as that of the first grating groove 3, and the second grating groove 6 forms the set texture.

[0045] In this embodiment, the first grating groove 3 is modified to obtain a modified groove 4, and a thin film layer 5 is plated in the modified groove 4 to form a second grating groove 6. In this way, the thin film layer 5 is formed on the surface of the first grating groove 3 without changing the size of the first grating groove 3, effectively ensuring the embossing accuracy of the hard mold obtained by improving the embossing sheet 1.

[0046] The hardness of the thin film layer 5 is greater than that of the adhesive layer 2. This allows the thin film layer 5 to effectively improve the hardness of the first grating grooves 3, thereby enabling the hard mold obtained by improving the embossing sheet 1 to meet the corresponding hardness requirements, ultimately achieving the purpose of improving the preparation efficiency of the hard mold.

[0047] In one example, the material of the adhesive layer 2 is UV nano-imprint adhesive.

[0048] It should be noted that, typically, the texture structure on the soft mold mirrors that of the hard mold. Users can transfer the texture structure on the hard mold to the product using the soft mold. The adhesive layer 2 of the imprint sheet 1 is made of a UV-type nanoimprint adhesive. This allows the adhesive layer 2 to be cured by UV light. This creates a structure that is less prone to deformation, and the resulting first grating grooves 3 have high dimensional accuracy. Furthermore, UV light irradiation is simple and easy to operate.

[0049] Another method for transferring the texture structure from the hard mold to the product using a soft mold is "hot embossing." This method uses heat to transfer the structure from the hard mold to the adhesive layer of the embossing sheet 1, followed by cooling to solidify the thermosetting embossing adhesive structure. This "hot embossing" method involves heating, which can cause deformation of the first grating grooves 3, hindering the achievement of high dimensional accuracy.

[0050] In one example, modifying the first grating groove 3 to form the modified groove 4 includes:

[0051] The first grating groove 3 is modified by a reactive ion beam etching process.

[0052] It should be noted that the principle of reactive ion beam etching process is:

[0053] Argon gas is decomposed into argon ions under the action of the glow discharge principle. The argon ions are accelerated by the anode electric field and physically bombard the sample surface to achieve the etching effect. Argon gas is filled into the ion source discharge chamber and ionized to form a plasma. Then, the ions are extracted and accelerated through the grid in a beam shape. The ion beam with a certain energy enters the working chamber and is fired at the solid surface to bombard the atoms on the solid surface, causing the material atoms to sputter and achieve the etching purpose. This is a pure physical etching.

[0054] The characteristics of reactive ion beam etching process are:

[0055] 1. Universality of ion beam etching:

[0056] Ion beam etching systems can etch a wide variety of materials, including many compounds and alloys, even without suitable volatile etchants. The target etch rate typically varies by no more than a factor of three due to material differences. Therefore, ion beam etching systems are widely used in the fabrication of YBaCuO, InAlGaAs, and other ternary and quaternary compound systems.

[0057] 2. Directionality of ion beam etching:

[0058] The directional nature of etching is due to the fact that the ions in the ion beam are accelerated by a strong vertical electric field. The very low pressure in the reaction chamber makes collisions between atoms almost impossible. As a result, when the atoms impact the wafer surface, their speed is close to that of a perfectly vertical one. Since it is independent of chemical properties, anisotropic etching can be performed on any material.

[0059] In the disclosed embodiment, the first grating grooves 3 are modified by a reactive ion beam etching process. A RIBE etcher can be used, with CHF3 as the working gas. The ion energy, acceleration voltage, and etching time are adjusted to control the etched groove shape of the modified grooves 4. This effectively improves the etching accuracy of the modified grooves 4, and the subsequent thin film layer 5 deposited in the modified grooves 4 also has a high degree of precision. Ultimately, the resulting second grating grooves 6 have the same dimensions as the first grating grooves 3. The use of the reactive ion beam etching process effectively improves the accuracy of the etching process.

[0060] In one example, the first grating groove 3 is modified to form a modified groove 4.

[0061] The ratio of the width of the modified groove 4 to the width of the first grating groove 3 is 1.2:1 to 1.5:1.

[0062] For example, if the ratio of the width of the modified groove 4 to the width of the first grating groove 3 is within the above-mentioned range, the thin film layer 5 deposited in the modified groove 4 can be deposited while maintaining the required hardness without excessive waste of thin film layer 5 material. Furthermore, etching the modified groove 4 too deeply means that more thin film layer 5 material will need to be subsequently deposited in the modified groove 4, which is detrimental to the improvement of the imprint sheet 1. Excessive deposition of thin film layer 5 material will affect the size of the first grating groove 3, thereby affecting the imprint accuracy of the hard mold produced by the imprint sheet 1.

[0063] In one example, a thin film layer 5 is deposited on the modified groove 4 to form a second grating groove 6, comprising:

[0064] A thin film layer 5 is deposited on the modified groove 4 by an atomic layer deposition process.

[0065] For example, atomic layer deposition (ALD) is a method that deposits a substance onto a substrate layer by layer in the form of a single-atom film. ALD allows for precise control of film thickness at the atomic level. Furthermore, multilayer structures of different materials can be formed relatively easily.

[0066] In this embodiment, the thin film layer 5 is plated on the modified groove 4 through the atomic layer thin film deposition process, which can effectively control the accuracy of the deposition thickness of the thin film layer 5, thereby avoiding the problem that an excessively thick thin film layer 5 affects the initial size of the first grating groove 3, thereby causing the hard mold imprinting error made by the imprinting sheet 1 to be too large.

[0067] In addition, the atomic layer deposition method can effectively adapt to the structure of the adhesive layer 2 itself, so that the deposited thin film layer 5 can match the structure of the modified groove 4, ensuring the effectiveness and accuracy of the imprinting sheet 1 provided with the thin film layer 5 in the subsequent imprinting process, and avoiding the uneven setting of the thin film layer 5 in the modified groove 4, which leads to imprinting errors during the imprinting process.

[0068] In one example, the material of the thin film layer 5 is silicon dioxide or titanium dioxide.

[0069] For example, a thin film layer 5 is plated on the modified groove 4. The material of the thin film layer 5 is silicon dioxide or titanium dioxide. The above materials of the thin film layer 5 have high strength, so that the thin film layer 5 disposed on the modified groove 4 can effectively improve the strength of the stamping sheet 1.

[0070] In one example, after coating the thin film layer 5 on the modified groove 4 to form the second grating groove 6, the method further includes:

[0071] The thin film layer 5 is subjected to a surface activation treatment.

[0072] For example, the film layer 5 may be subjected to a surface activation treatment to activate the surface effect of the film layer 5 so that the surface of the film layer 5 has good wettability, thereby allowing the film layer 5 to adhere well to the adhesive material during subsequent spraying, bonding, printing, or pressure welding processes.

[0073] In one example, the surface activation treatment of the thin film layer 5 is performed by a plasma cleaning process.

[0074] For example, a plasma cleaning machine can be used with a power of 500W, an O2 working gas at a flow rate of 50 sccm, and a cleaning time of 100s to perform surface activation treatment on the thin film layer 5 on the imprinted sheet 1 .

[0075] Specifically, in the plasma cleaning process, the stamped sheet 1 is dry after being cleaned by the plasma cleaning equipment and can be sent to the next process without further drying, thereby improving the processing efficiency of the entire process line.

[0076] Plasma cleaning allows the operator to avoid harm to the human body caused by harmful solvents, and also avoids the problem of easily damaging the stamped sheet 1 in wet cleaning.

[0077] The plasma cleaning process avoids the use of harmful ODS solvents such as trichloroethane, so no harmful pollutants are produced after cleaning. Therefore, this cleaning method is an environmentally friendly green cleaning method.

[0078] Plasma cleaning equipment uses high frequencies in the radio wave range to generate plasma, which differs from direct light such as lasers. Plasma has a low directivity, allowing it to penetrate deep into tiny pores and recesses, eliminating the need to consider the shape of the stamped sheet.

[0079] Plasma cleaning can significantly improve cleaning efficiency. The entire cleaning process can be completed in just a few minutes, resulting in high productivity.

[0080] Plasma cleaning requires a controlled vacuum of approximately 100 Pa, a condition easily achieved. This reduces the equipment cost, and the fact that the cleaning process does not require the use of expensive organic solvents significantly reduces overall cleaning costs.

[0081] The plasma cleaning process avoids the transportation, storage, discharge and other treatment measures of the cleaning fluid, so the production site is easy to keep clean and hygienic.

[0082] Plasma cleaning is a process that can be applied to a wide variety of materials, regardless of the target. Whether metals, semiconductors, oxides, or polymers (such as polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyimide, polyester, epoxy resin, and other polymers), plasma can be used to treat them. Therefore, plasma is particularly suitable for materials that are sensitive to heat and solvents. Furthermore, plasma can be used to selectively clean entire materials, parts of them, or even complex structures.

[0083] The plasma cleaning process can not only clean and remove dirt, but also improve the surface properties of the material itself, such as improving the surface wettability and improving the adhesion of the film.

[0084] In one example, Figure 5 As shown, after the film layer 5 is subjected to surface activation treatment, the following steps are further included:

[0085] An anti-stick layer 7 is applied on the film layer 5 .

[0086] For example, a coating machine can be used to apply the anti-sticking layer 7 so that the anti-sticking layer 7 can be evenly disposed on the surface of the film layer 5. Providing the anti-sticking layer 7 on the surface of the film layer 5 can reduce the ejection force between the hard mold obtained by improving the embossing sheet 1 and the soft mold during the subsequent embossing process, thereby preventing the problem of mold release failure caused by adhesion between the soft mold and the hard mold.

[0087] In one example, the material of the anti-sticking layer 7 is a fluorine-containing low surface energy organic compound.

[0088] For example, the material of the anti-sticking layer 7 is an anti-sticking agent used for nanoimprinting containing fluorosilane.

[0089] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0090] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for preparing a nanoimprint hard mold, characterized in that: include: Providing an embossing sheet, the embossing sheet having an adhesive layer, the adhesive layer being formed with first grating grooves, the first grating grooves forming a set pattern; Modifying the first grating groove to form a modified groove, wherein the width of the modified groove is greater than the width of the first grating groove, and the depth of the modified groove is equal to the depth of the first grating groove; A thin film layer is plated on the modified groove to form a second grating groove. The hardness of the thin film layer is greater than that of the glue layer. The size of the second grating groove is the same as that of the first grating groove. The second grating groove forms the set texture.

2. The preparation method according to claim 1, characterized in that The material of the adhesive layer is UV nano-imprint adhesive.

3. The preparation method according to claim 1, characterized in that The step of modifying the first grating groove to form a modified groove comprises: The first grating grooves are modified by a reactive ion beam etching process.

4. The preparation method according to claim 1, characterized in that The first grating groove is modified to form a modified groove, The ratio of the width of the modified groove to the width of the first grating groove is 1.2:1 to 1.5:

1.

5. The preparation method according to claim 1, characterized in that The step of coating a thin film layer on the modified groove to form a second grating groove comprises: A thin film layer is deposited on the modified groove by an atomic layer thin film deposition process.

6. The preparation method according to claim 1, characterized in that The material of the thin film layer is silicon dioxide or titanium dioxide.

7. The preparation method according to claim 1, characterized in that After coating a thin film layer on the modified groove to form a second grating groove, the method further comprises: The film layer is subjected to surface activation treatment.

8. The preparation method according to claim 7, characterized in that The thin film layer is subjected to surface activation treatment by a plasma cleaning process.

9. The preparation method according to claim 7, characterized in that After the film layer is subjected to surface activation treatment, the method further comprises: An anti-stick layer is coated on the film layer.

10. The preparation method according to claim 9, characterized in that The material of the anti-sticking layer is a fluorine-containing low surface energy organic matter.

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