Impressing female template and preparation method thereof

Abstract

The invention provides an imprinting female template and a preparation method thereof. The imprinting female template comprises a substrate layer, a pattern layer and a plasma enhancement layer which are sequentially stacked; the base layer is made of first perfluoroalkoxy resin, and the pattern layer is made of second perfluoroalkoxy resin and filler. According to the invention, the structure of the imprinting master template, the material of the pattern layer and the material of the substrate layer are designed, and the perfluoroalkoxy resin is further used, so that the imprinting master template with excellent performance is prepared. The imprinting female template provided by the invention has relatively high rigidity, relatively high resolution processing and relatively good thermal stability, and also has inertia and extremely low adhesion to PDMS on the premise of not arranging a temporary anti-sticking layer, so that the process integration level and the operation stability are improved, the service life of the template is prolonged, and the repeatability and the precision of nanostructure manufacturing are improved.

Description

Technical Field

[0001] This invention belongs to the field of nanoimprint template material technology, specifically relating to an imprint template and its preparation method. Background Technology

[0002] In the field of nanoimprint lithography, traditional hard templates (such as silicon and quartz) are indispensable tools in micro- and nano-manufacturing due to their excellent hardness and thermal stability, enabling high-precision and high-resolution pattern replication. However, these materials have high surface energy, making them prone to adhesion when transferring patterns with soft materials such as polydimethylsiloxane (PDMS), leading to difficulties in demolding and even damage to the pattern structure. To solve this problem, it is necessary to repeatedly coat the surface of the hard template with anti-stick coatings such as fluorosilanes to reduce its surface energy. This additional step not only significantly increases the complexity and time cost of the process but also introduces a series of reliability issues: the anti-stick layer is prone to degradation or local failure under mechanical friction, high temperature, and chemical action, resulting in PDMS residue during demolding, which seriously affects the consistency and yield of the transfer quality. At the same time, the uniformity of the coating and the stability of repeated coatings are also difficult to guarantee, becoming a key bottleneck restricting the efficiency and large-scale application of nanoimprint lithography technology.

[0003] Therefore, the development of a new type of rigid template material is particularly urgent. This material must retain the high rigidity, high-resolution processing, and thermal stability of traditional rigid templates, while its surface should naturally possess inertness and extremely low adhesion to PDMS. Such a material has the potential to fundamentally eliminate the reliance on temporary anti-stick coatings, thereby significantly improving process integration, operational stability, and template lifespan. This will not only reduce production and maintenance costs but also improve the repeatability and precision of nanostructure manufacturing. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an imprinting master template and its preparation method. The present invention designs the structure of the imprinting master template, as well as the graphic layer and base layer materials, and further utilizes perfluoroalkoxy resin to prepare an imprinting master template with excellent performance. The imprinting master template provided by the present invention possesses high rigidity, high-resolution processing capability, high precision, and good thermal stability. Furthermore, without the need for a temporary anti-stick coating, it exhibits inertness and low adhesion to PDMS, improving process integration, operational stability, template lifespan, and the repeatability and precision of nanostructure manufacturing.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides an embossing master template, the embossing master template comprising a base layer, a pattern layer and a plasma reinforcement layer stacked sequentially; the base layer is made of a first perfluoroalkoxy resin, and the pattern layer is made of a second perfluoroalkoxy resin and a filler.

[0007] Perfluoroalkoxy resins naturally possess inertness and low adhesion to PDMS. Furthermore, the transparent nature of perfluoroalkoxy resins after molding allows ultraviolet light to pass through, which is beneficial for the photocuring of the PDMS precursor filled onto the master mold. Other fluorinated resins, such as polytetrafluoroethylene (PTFE), are soft and opaque, resulting in poor rigidity and transparency of the prepared imprinting master mold. Their inherent mechanical strength and micro / nano processing properties remain major obstacles to their direct use as high-resolution hard templates. Additionally, the excessively high mechanical strength of ethylene-tetrafluoroethylene copolymers makes it difficult to reduce mechanical strength by controlling molecular weight, complicating the process.

[0008] This invention designs an imprinting master template by using a first perfluoroalkoxy resin as the pattern layer material and a second perfluoroalkoxy resin as the base layer material, thus preparing an imprinting master template with excellent performance. The imprinting master template provided by this invention has high rigidity, high transparency, high-resolution processing capability, and good thermal stability. Furthermore, without the need for a temporary anti-stick coating, it also exhibits inertness and extremely low adhesion to PDMS, improving process integration, operational stability, template lifespan, and the repeatability and precision of nanostructure manufacturing.

[0009] The use of filler in the pattern layer of this invention can further improve the rigidity of the embossing master template, thereby further improving the embossing accuracy of the embossing master template.

[0010] It should be noted that the graphic structure of the graphic layer in the embossing master template provided by the present invention has no special limitations and can be designed according to actual needs. The graphic structure includes, but is not limited to, protrusions or depressions, such as cylinders, cones, frustums, V-shaped pits, etc.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0012] Preferably, the number average molecular weight of the first perfluoroalkoxy resin is 100,000 to 200,000, for example, it can be 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000 or 200,000.

[0013] The first perfluoroalkoxy resin with a low number-average molecular weight has moderate elasticity and hardness, and a certain degree of deformation capability. The substrate layer prepared by this first perfluoroalkoxy resin has suitable elasticity and hardness and a certain degree of deformation capability. The substrate layer is not completely rigid, which is beneficial for its adhesion and adaptation to different imprinting objects, which can be planar, curved, or other irregular surfaces.

[0014] Preferably, the number average molecular weight of the second perfluoroalkoxy resin is 200,000 to 500,000, for example, it can be 200,000, 220,000, 250,000, 270,000, 300,000, 330,000, 350,000, 370,000, 400,000, 420,000, 440,000, 460,000, 480,000 or 500,000.

[0015] Second-perfluoroalkoxy resins with high number-average molecular weight exhibit low elasticity, high hardness, and excellent creep resistance. They show minimal deformation under sustained high temperatures and stress, resulting in superior long-term reliability. Patterned layers prepared using this second-perfluoroalkoxy resin exhibit good performance, and the resulting embossing master templates demonstrate good precision and stability.

[0016] This invention makes the mechanical properties (elasticity, hardness) of the embossing master template controllable by selecting perfluoroalkoxy resins with different number-average molecular weights as the base layer and pattern layer, respectively.

[0017] Preferably, the filler comprises any one or a combination of at least two of graphite, molybdenum dioxide nanoparticles, and tungsten trioxide nanoparticles.

[0018] Preferably, the average particle size of the filler is ≤5 nm, for example, it can be 0.1 nm, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm or 5 nm, etc.

[0019] Preferably, based on a mass percentage of 100 wt% for the material formed in the figure, the mass percentage of the filler is 0.1-5 wt%, for example, it can be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%, etc.

[0020] This invention uses the aforementioned filler and a second perfluoroalkoxy resin as the materials for the pattern layer, resulting in a pattern layer with excellent performance. The filler has no negative impact on the anti-sticking ability of PDMS, but it does improve the rigidity of the imprinting master template. This invention helps reduce surface protrusions in the pattern layer by controlling the amount, type, and average particle size of the filler. If the average particle size of the filler is >5 nm, the surface of the pattern layer in the prepared imprinting master template is too rough, resulting in poor repeatability and precision in the fabrication of nanostructures. If the filler content in the pattern layer is <0.1 wt%, the rigidity of the prepared imprinting master template is poor. If the filler content in the pattern layer is >5 wt%, the rigidity of the imprinting master template will be too high, and the surface of the pattern layer will be relatively rough.

[0021] Preferably, the thickness of the substrate layer is ≥30 mm (e.g., it can be 30 mm, 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, 42 mm, 44 mm, 46 mm, 48 mm, 50 mm, 52 mm, 55 mm or 57 mm, etc.), and more preferably 30-50 mm.

[0022] Preferably, the thickness of the graphic layer is 2-20 mm, for example, it can be 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm or 20 mm, etc.

[0023] Preferably, the thickness of the plasma enhancement layer is 5-20 nm, for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm, etc.

[0024] In a second aspect, the present invention provides a method for preparing an imprint master template as described in the first aspect, the method comprising the following steps:

[0025] (1) The material of the graphic layer is injection molded on the substrate with the pattern, and the material is held under pressure and cooled to obtain the graphic layer; wherein the pattern on the substrate is complementary to the pattern in the graphic layer of the imprinting master template.

[0026] (2) Inject the base layer material on the side of the pattern layer away from the substrate, hold pressure and cool to obtain a base layer and a pattern layer that are in contact;

[0027] (3) Under a protective atmosphere, the substrate layer and the pattern layer that are bonded together are irradiated and then subjected to plasma treatment to form a plasma enhancement layer on the side of the pattern layer away from the substrate layer, thereby obtaining the imprint master template.

[0028] In this invention, the rigidity of the embossing master template can be improved by irradiating the mating base layer and pattern layer in step (3).

[0029] Preferably, the patterned substrate is prepared by the following method, which includes the following steps: plating chromium on the substrate to obtain a chromium layer, coating photoresist on the side of the chromium layer away from the substrate, exposing and developing with an electron beam, and dry etching to form a pattern in the chromium layer that is complementary to the pattern in the patterned layer of the imprint master template, thereby completing the preparation of the patterned substrate.

[0030] It should be noted that dry etching does not penetrate the chromium layer; this is because chromium has extremely low compatibility with PFA (perfluoroalkoxy resin), which is beneficial for subsequent demolding.

[0031] Preferably, the substrate comprises a quartz substrate.

[0032] Preferably, step (1) further includes a pretreatment step before injection molding, wherein the pretreatment method includes a first pre-drying treatment of the material of the graphic layer.

[0033] Preferably, the temperature of the first pre-drying treatment is 110-130℃ (e.g., it can be 110℃, 112℃, 114℃, 116℃, 118℃, 120℃, 122℃, 124℃, 126℃, 128℃ or 130℃, etc.), and the time is 5-7 h (e.g., it can be 5 h, 5.5 h, 6 h, 6.5 h or 7 h, etc.).

[0034] Preferably, the injection molding in step (1) includes a first melt plasticizing and a first high-pressure injection.

[0035] Preferably, the temperature of the first melting and plasticizing is 330-370℃, for example, it can be 330℃, 335℃, 340℃, 345℃, 350℃, 355℃, 360℃, 365℃ or 370℃, etc.

[0036] Preferably, the temperature of the first melting and plasticizing feeding zone is 310-330℃ (e.g., it can be 310℃, 312℃, 314℃, 316℃, 318℃, 320℃, 322℃, 324℃, 326℃, 328℃, or 330℃, etc.), the temperature of the plasticizing zone is 340-360℃ (e.g., it can be 340℃, 342℃, 344℃, 346℃, 348℃, 350℃, 352℃, 354℃, 356℃, 358℃, or 360℃, etc.), and the temperature of the injection zone is 350-370℃ (e.g., it can be 350℃, 352℃, 354℃, 356℃, 358℃, 360℃, 362℃, 364℃, 366℃, 368℃, or 370℃, etc.).

[0037] Preferably, the pressure of the first high-pressure injection is 100-150 MPa, for example, it can be 100 MPa, 105 MPa, 110 MPa, 115 MPa, 120 MPa, 125 MPa, 130 MPa, 135 MPa, 140 MPa, 145 MPa or 150 MPa, etc.

[0038] Preferably, the temperature of the mold used in the injection molding in step (1) is 180-230℃, for example, it can be 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, 220℃, 225℃ or 230℃, etc.

[0039] In this invention, the mold used in the injection molding process in step (1) is kept within a high range, and internal stress is reduced by using a high mold temperature.

[0040] Preferably, the pressure holding and cooling time in step (1) is 6-9 hours, for example, it can be 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours or 9 hours.

[0041] Preferably, the pressure holding and cooling process further includes a demolding step.

[0042] Preferably, step (2) further includes a pretreatment step before injection molding, wherein the pretreatment method includes a second pre-drying treatment of the substrate material.

[0043] Preferably, the temperature of the second pre-drying treatment is 110-130℃ (e.g., it can be 110℃, 112℃, 114℃, 116℃, 118℃, 120℃, 122℃, 124℃, 126℃, 128℃ or 130℃, etc.), and the time is 5-7 h (e.g., it can be 5 h, 5.5 h, 6 h, 6.5 h or 7 h, etc.).

[0044] Preferably, the injection molding in step (2) includes a second melt plasticizing and a second high-pressure injection.

[0045] Preferably, the second melting and plasticizing temperature is 330-370°C, for example, it can be 330°C, 335°C, 340°C, 345°C, 350°C, 355°C, 360°C, 365°C or 370°C, etc.

[0046] Preferably, the temperature of the second melting and plasticizing feeding zone is 310-330℃ (e.g., it can be 310℃, 312℃, 314℃, 316℃, 318℃, 320℃, 322℃, 324℃, 326℃, 328℃, or 330℃, etc.), the temperature of the plasticizing zone is 340-360℃ (e.g., it can be 340℃, 342℃, 344℃, 346℃, 348℃, 350℃, 352℃, 354℃, 356℃, 358℃, or 360℃, etc.), and the temperature of the injection zone is 350-370℃ (e.g., it can be 350℃, 352℃, 354℃, 356℃, 358℃, 360℃, 362℃, 364℃, 366℃, 368℃, or 370℃, etc.).

[0047] Preferably, the pressure of the second high-pressure injection is 100-150 MPa, for example, it can be 100 MPa, 105 MPa, 110 MPa, 115 MPa, 120 MPa, 125 MPa, 130 MPa, 135 MPa, 140 MPa, 145 MPa or 150 MPa, etc.

[0048] Preferably, the temperature of the mold used in the injection molding in step (2) is 180-230℃, for example, it can be 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, 220℃, 225℃ or 230℃, etc.

[0049] In this invention, the mold used in injection molding in step (2) is controlled to be within a high range, and internal stress is reduced by high mold temperature.

[0050] Preferably, the pressure holding and cooling time in step (2) is 6-9 hours, for example, it can be 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours or 9 hours.

[0051] Preferably, the pressure holding and cooling process further includes a demolding step.

[0052] Preferably, the protective gas includes nitrogen.

[0053] Preferably, the wavelength used for irradiation is 280-315 nm, such as 280 nm, 285 nm, 290 nm, 295 nm, 300 nm, 305 nm, 310 nm or 315 nm.

[0054] Preferably, the irradiation time is 1-2 hours, for example, 1 hour, 1.5 hours or 2 hours.

[0055] Preferably, the plasma treatment is performed in an F-based plasma atmosphere.

[0056] Preferably, the plasma treatment time is 25-35 min, for example, it can be 25 min, 26 min, 27 min, 28 min, 29 min, 30 min, 31 min, 32 min, 33 min, 34 min or 35 min, etc.

[0057] Plasma treatment in an F-based plasma atmosphere makes the surface of the patterned layer smoother and further increases the F atom concentration on the surface of the patterned layer, forming a plasma reinforcement layer and improving the anti-sticking performance of the imprinting master template.

[0058] Preferably, the method for preparing the imprint master template specifically includes the following steps:

[0059] (1) Chromium is plated on the substrate to obtain a chromium layer. Photoresist is coated on the side of the chromium layer away from the substrate. Electron beam exposure, development, and dry etching are used to form a pattern in the chromium layer that is complementary to the pattern in the pattern layer of the imprint master template, and a substrate with a pattern is obtained.

[0060] The material of the graphic layer after the first pre-drying treatment is injected onto the patterned substrate, held under pressure and cooled for 6-9 hours, and then demolded to obtain the graphic layer; wherein the pattern on the substrate is complementary to the pattern in the graphic layer of the embossing master template, the temperature of the first pre-drying treatment is 110-130℃ and the time is 5-7 hours, the injection molding includes the first melt plasticizing and the first high-pressure injection, the temperature of the feeding zone of the first melt plasticizing is 310-330℃, the temperature of the plasticizing zone is 340-360℃, the temperature of the injection zone is 350-370℃, the pressure of the first high-pressure injection is 100-150 MPa, and the temperature of the mold used in the injection molding process is 180-230℃;

[0061] (2) Inject the material of the base layer after the second pre-drying treatment on the side of the graphic layer away from the substrate, hold pressure and cool for 6-9 h, demold, and obtain the base layer and graphic layer that are in contact; wherein, the temperature of the second pre-drying treatment is 110-130℃ and the time is 5-7 h, the injection molding includes the second melt plasticizing and the second high pressure injection, the temperature of the feeding zone of the second melt plasticizing is 310-330℃, the temperature of the plasticizing zone is 340-360℃, the temperature of the injection zone is 350-370℃, the pressure of the second high pressure injection is 100-150 MPa, and the temperature of the mold used in the injection molding process is 180-230℃;

[0062] (3) Under a protective atmosphere, at a wavelength of 280-315 nm, the substrate layer and pattern layer are irradiated for 1-2 h, and then plasma-treated for 25-35 min under an F-based plasma atmosphere to form a plasma enhancement layer on the side of the pattern layer away from the substrate layer, thus obtaining the imprint master template.

[0063] It should be noted that the present invention does not impose any special limitations on the exposure, development, and dry etching methods when preparing substrates with patterns, and all commonly used methods and process conditions in the art are applicable.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] (1) This invention designs the structure of the imprinting master template and the materials of the graphic layer and the base layer, and further prepares an imprinting master template with excellent performance by using perfluoroalkoxy resin. The imprinting master template provided by this invention has high rigidity, high resolution processing and good thermal stability. At the same time, without the need to set a temporary anti-sticking layer, it also has inertness and extremely low adhesion to PDMS, which improves the process integration, operational stability and template service life, and the repeatability and precision of nanostructure manufacturing.

[0066] (2) By controlling the average particle size of the filler to ≤5 nm and controlling the amount of filler in the pattern layer to 0.1-5 wt%, the present invention can further improve the overall performance of the embossing master template.

[0067] (3) By designing a medium molecular weight perfluoroalkoxy resin as the base layer material and a high molecular weight perfluoroalkoxy resin as the main resin of the pattern layer, the present invention further improves the overall performance of the embossing master template. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the structure of the embossing master template provided in Embodiment 1 of the present invention;

[0069] Among them, 1-base layer, 2-patterning layer, 3-plasma enhancement layer;

[0070] Figure 2 This is a schematic diagram of the preparation process of the imprint master template provided in Embodiment 1 of the present invention. Detailed Implementation

[0071] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0072] The sources of some components in the following examples and comparative examples are shown in Table 1 below:

[0073] Table 1

[0074]

[0075] Example 1

[0076] This embodiment provides an embossing master template and its preparation method. A schematic diagram of the embossing master template is shown below. Figure 1 As shown, it includes a base layer 1, a pattern layer 2, and a plasma enhancement layer 3 stacked sequentially.

[0077] The base layer 1 is made of perfluoroalkoxy resin-1 and has a thickness of 30 mm.

[0078] The material of the patterned layer 2 is perfluoroalkoxy resin-3 (98 wt%) and graphite (2 wt%), and the thickness is 12 mm;

[0079] The thickness of the plasma enhancement layer 3 is 10 nm;

[0080] The preparation process of the above-mentioned imprinting master template is as follows: Figure 2 As shown, its preparation method is as follows:

[0081] (1) Chromium is plated on a substrate (quartz glass) to obtain a chromium layer. Photoresist is coated on the side of the chromium layer away from the substrate. Electron beam exposure, development, and dry etching are used to form a pattern in the chromium layer that is complementary to the pattern in the pattern layer of the imprint master template, and a substrate with a pattern is obtained.

[0082] The material of the graphic layer 2, which has undergone the first pre-drying treatment, is injected onto a substrate with a pattern. After holding the pressure and cooling for 7 hours, the material is demolded to obtain the graphic layer 2. The pattern on the substrate is complementary to the pattern in the graphic layer 2 of the embossing master template. The temperature of the first pre-drying treatment is 120°C and the time is 6 hours. The injection molding includes the first melt plasticizing and the first high-pressure injection. The temperature of the feeding zone of the first melt plasticizing is 320°C, the temperature of the plasticizing zone is 350°C, the temperature of the injection zone is 360°C, the pressure of the first high-pressure injection is 120 MPa, and the temperature of the mold used in the injection molding process is 200°C.

[0083] (2) Inject the material of the base layer 1 that has undergone the second pre-drying treatment into the side of the graphic layer 2 away from the substrate, hold the pressure and cool for 7 h, demold, and obtain the base layer 1 and graphic layer 2 that are in contact; wherein, the temperature of the second pre-drying treatment is 120°C and the time is 6 h, the injection molding includes the second melt plasticizing and the second high-pressure injection, the temperature of the feeding zone of the second melt plasticizing is 320°C, the temperature of the plasticizing zone is 350°C, the temperature of the injection zone is 370°C, the pressure of the second high-pressure injection is 140 MPa, and the temperature of the mold used in the injection molding process is 210°C;

[0084] (3) Under a nitrogen atmosphere and at a wavelength of 280-315 nm, the substrate layer 1 and the pattern layer 2 are subjected to ultraviolet light irradiation for 1.5 h, and then plasma treatment is performed in an F-based plasma atmosphere for 30 min to form a plasma enhancement layer 3 on the side of the pattern layer 2 away from the substrate layer, thus obtaining the imprint master template.

[0085] Example 2

[0086] This embodiment provides an imprinting master template and its preparation method. The imprinting master template includes a base layer, a pattern layer, and a plasma reinforcement layer stacked sequentially.

[0087] The base layer is made of perfluoroalkoxy resin-2 and has a thickness of 40 mm.

[0088] The patterned layer is made of perfluoroalkoxy resin-3 (99 wt%) and molybdenum dioxide nanoparticles (1 wt%), and has a thickness of 18 mm.

[0089] The thickness of the plasma enhancement layer is 12 nm;

[0090] The preparation method of the above-mentioned imprinting master template is as follows:

[0091] (1) Chromium is plated on a substrate (quartz glass) to obtain a chromium layer. Photoresist is coated on the side of the chromium layer away from the substrate. Electron beam exposure, development, and dry etching are used to form a pattern in the chromium layer that is complementary to the pattern in the pattern layer of the imprint master template, and a substrate with a pattern is obtained.

[0092] The material of the graphic layer after the first pre-drying treatment is injected onto the patterned substrate, held under pressure and cooled for 8 hours, and then demolded to obtain the graphic layer; wherein the pattern on the substrate is complementary to the pattern in the graphic layer of the embossing master template, the temperature of the first pre-drying treatment is 120°C and the time is 6 hours, the injection molding includes the first melt plasticizing and the first high-pressure injection, the temperature of the feeding zone of the first melt plasticizing is 330°C, the temperature of the plasticizing zone is 360°C, the temperature of the injection zone is 370°C, the pressure of the first high-pressure injection is 140MPa, and the temperature of the mold used in the injection molding process is 230°C;

[0093] (2) Inject the material of the base layer after the second pre-drying treatment on the side of the graphic layer away from the substrate, hold pressure and cool for 8 hours, demold, and obtain the base layer and graphic layer that are in contact; wherein, the temperature of the second pre-drying treatment is 120°C and the time is 6 hours, the injection molding includes the second melt plasticizing and the second high-pressure injection, the temperature of the feeding zone of the second melt plasticizing is 330°C, the temperature of the plasticizing zone is 360°C, the temperature of the injection zone is 370°C, the pressure of the second high-pressure injection is 120 MPa, and the temperature of the mold used in the injection molding process is 220°C;

[0094] (3) Under a nitrogen atmosphere and at a wavelength of 280-315 nm, the substrate layer and the pattern layer are subjected to ultraviolet light irradiation for 1 h, and then plasma treatment is performed in an F-based plasma atmosphere for 32 min to form a plasma enhancement layer on the side of the pattern layer away from the substrate layer, thus obtaining the imprint master template.

[0095] Example 3

[0096] This embodiment provides an imprinting master template and its preparation method. The imprinting master template includes a base layer, a pattern layer, and a plasma reinforcement layer stacked sequentially.

[0097] The base layer is made of perfluoroalkoxy resin-1 and has a thickness of 35 mm.

[0098] The patterned layer is made of perfluoroalkoxy resin-4 (97 wt%) and tungsten trioxide nanoparticles-1 (3 wt%), and has a thickness of 5 mm.

[0099] The thickness of the plasma enhancement layer is 10 nm;

[0100] The preparation method of the above-mentioned imprinting master template is as follows:

[0101] (1) Chromium is plated on a substrate (quartz glass) to obtain a chromium layer. Photoresist is coated on the side of the chromium layer away from the substrate. Electron beam exposure, development, and dry etching are used to form a pattern in the chromium layer that is complementary to the pattern in the pattern layer of the imprint master template, and a substrate with a pattern is obtained.

[0102] The material of the graphic layer after the first pre-drying treatment is injected onto the patterned substrate, held under pressure and cooled for 6 hours, and then demolded to obtain the graphic layer; wherein the pattern on the substrate is complementary to the pattern in the graphic layer of the embossing master template, the temperature of the first pre-drying treatment is 120°C and the time is 6 hours, the injection molding includes the first melt plasticizing and the first high-pressure injection, the temperature of the feeding zone of the first melt plasticizing is 310°C, the temperature of the plasticizing zone is 340°C, the temperature of the injection zone is 360°C, the pressure of the first high-pressure injection is 110MPa, and the temperature of the mold used in the injection molding process is 230°C;

[0103] (2) Inject the material of the base layer after the second pre-drying treatment on the side of the graphic layer away from the substrate, hold pressure and cool for 6 hours, demold, and obtain the base layer and graphic layer that are in contact; wherein, the temperature of the second pre-drying treatment is 120°C and the time is 6 hours, the injection molding includes the second melt plasticizing and the second high-pressure injection, the temperature of the feeding zone of the second melt plasticizing is 310°C, the temperature of the plasticizing zone is 340°C, the temperature of the injection zone is 360°C, the pressure of the second high-pressure injection is 140 MPa, and the temperature of the mold used in the injection molding process is 190°C;

[0104] (3) Under a nitrogen atmosphere and at a wavelength of 280-315 nm, the substrate layer and the pattern layer are subjected to ultraviolet light irradiation for 1.5 h, and then plasma treatment is performed in an F-based plasma atmosphere for 30 min to form a plasma enhancement layer on the side of the pattern layer away from the substrate layer, thus obtaining the imprint master template.

[0105] Example 4

[0106] This embodiment provides an embossing master template and its preparation method. The only difference from Embodiment 1 is that the material of the pattern layer is perfluoroalkoxy resin-3 (99.9 wt%) and graphite (0.1 wt%), and the other conditions are the same as in Embodiment 1.

[0107] Example 5

[0108] This embodiment provides an embossing master template and its preparation method. The only difference from Embodiment 1 is that the material of the pattern layer is perfluoroalkoxy resin-3 (95 wt%) and graphite (5 wt%), while the other conditions are the same as in Embodiment 1.

[0109] Example 6

[0110] This embodiment provides an embossing master template and its preparation method. The only difference from Embodiment 1 is that the material of the pattern layer is perfluoroalkoxy resin-3 (99.95 wt%) and graphite (0.05 wt%), while the other conditions are the same as in Embodiment 1.

[0111] Example 7

[0112] This embodiment provides an embossing master template and its preparation method. The only difference from Embodiment 1 is that the material of the pattern layer is perfluoroalkoxy resin-3 (93 wt%) and graphite (7 wt%), while the other conditions are the same as in Embodiment 1.

[0113] Example 8

[0114] This embodiment provides an imprinting master template and its preparation method. The only difference from Embodiment 3 is that tungsten trioxide nanoparticles-1 are replaced with an equal amount of tungsten trioxide nanoparticles-2, while other conditions are the same as in Embodiment 3.

[0115] Example 9

[0116] This embodiment provides an imprinting master template and its preparation method. The only difference from Embodiment 1 is that the material of the base layer is perfluoroalkoxy resin-3, and the other conditions are the same as in Embodiment 1.

[0117] Example 10

[0118] This embodiment provides an embossing master template and its preparation method. The only difference from Embodiment 1 is that the material of the pattern layer is perfluoroalkoxy resin-1 (98 wt%) and graphite (2 wt%), while the other conditions are the same as in Embodiment 1.

[0119] Example 11

[0120] This embodiment provides an imprinting master template and its preparation method. The only difference from Embodiment 1 is that the material of the base layer is perfluoroalkoxy resin-A, and the other conditions are the same as in Embodiment 1.

[0121] Example 12

[0122] This embodiment provides an embossing master template and its preparation method. The only difference from Embodiment 1 is that the material of the pattern layer is perfluoroalkoxy resin-B (98 wt%) and graphite (2 wt%), while the other conditions are the same as in Embodiment 1.

[0123] Comparative Example 1

[0124] This comparative example provides an embossing master template and its preparation method. The only difference from Example 1 is that the material of the base layer is polytetrafluoroethylene, and the material of the pattern layer is polytetrafluoroethylene (98 wt%) and graphite (2 wt%). Other conditions are the same as in Example 1.

[0125] Comparative Example 2

[0126] This comparative example provides an imprinting master template and its preparation method. The difference from Example 1 is that the imprinting master template does not have a plasma reinforcement layer.

[0127] Step (3) in the above method for preparing the imprint master template is as follows:

[0128] (3) Under a nitrogen atmosphere, at a wavelength of 280-315 nm, the bonded substrate layer and pattern layer are irradiated for 1.5 h to obtain the imprint master template;

[0129] Other conditions are the same as in Example 1.

[0130] The performance of the imprinting master templates provided in the above embodiments and comparative examples was tested, and the specific test methods are as follows:

[0131] Tensile test: The rigidity was quantitatively characterized by measuring the Young's Modulus of the imprinting master templates (cut to a length of 10 cm, a width of 2 cm, and a thickness equal to the overall thickness of the imprinting master template) provided in the above embodiments and comparative examples using a tensile testing machine.

[0132] Accuracy: The microstructure of the imprint master templates provided in the above examples and comparative examples was observed using a scanning electron microscope (SEM) to confirm the accuracy of the prepared imprint master templates;

[0133] Thermal stability: Differential scanning calorimetry (DSC) was used to measure the heat flow changes of the imprint master templates provided in the above embodiments and comparative examples when phase transitions (such as melting points) occurred under programmed temperature control;

[0134] Transparency: The total light transmittance and haze of the imprinting master templates provided in the above embodiments and comparative examples were measured using an integrating sphere haze meter.

[0135] Service life: The nanostructures prepared using the imprint master templates provided in the above embodiments and comparative examples are accumulated. If the number of uses is less than 100, it is deemed unqualified.

[0136] Adhesion to PDMS: After the embossing master templates provided in the above embodiments and comparative examples were bonded to PDMS, the force required for peeling per unit width was measured at 90°.

[0137] The performance of the imprinting master templates provided in the embodiments and comparative examples of the present invention, using the above method, was tested and found that:

[0138] This invention designs an embossing master template by considering its structure, graphic layer materials, and base layer materials. Through the use of perfluoroalkoxy resin and further design of fillers in the graphic layer, it achieves an embossing master template with suitable rigidity, high-resolution processing capabilities, and good thermal stability. This embossing master template exhibits inertness and extremely low adhesion to PDMS without requiring a temporary anti-stick coating, improving process integration, operational stability, template lifespan, and the repeatability and precision of nanostructure manufacturing.

[0139] In the imprinting master templates provided in Examples 1-5 of this invention, perfluoroalkoxy resin with a number average molecular weight of 100,000-200,000 is used as the base layer material, which gives the imprinting master template a certain deformation capability and can be adapted to different imprinting objects; perfluoroalkoxy resin with a number average molecular weight of 200,000-500,000 is used as the pattern layer material, and the amount of filler with an average particle size ≤5 nm in the pattern layer is controlled at 0.1-5 wt%, so that the pattern layer of the imprinting master template has high tensile modulus and hardness and small deformation, ensuring the repeatability and precision of the nanostructure fabrication prepared by the imprinting master template.

[0140] Compared with Example 1, the amount of filler in the pattern layer of the imprint master template provided in Example 6 is too small, which will result in low tensile strength and poor rigidity of the imprint master template; the amount of filler in the imprint master template provided in Example 7 is too large, and the average particle size of the filler in the imprint master template provided in Example 9 is too large. Both of these will result in the surface of the prepared imprint master template being too rough, which will lead to a decrease in the repeatability and precision of the nanostructure fabrication prepared by the imprint master template.

[0141] Compared to Example 1, the imprinting master template provided in Example 10 uses high molecular weight perfluoroalkoxy resin for both the base layer and the pattern layer, resulting in excessive rigidity that makes it unsuitable for different imprinting objects and reduces its service life. The imprinting master template provided in Example 11 uses low molecular weight perfluoroalkoxy resin for both the base layer and the pattern layer, resulting in poor rigidity, low hardness, and poor creep resistance. It is prone to deformation under high stress or temperature, leading to reduced repeatability and precision in the fabrication of nanostructures. The imprinting master template provided in Example 12 uses perfluoroalkoxy resin with a number-average molecular weight of less than 100,000 for the base layer, resulting in poor hardness and potentially rendering the imprinting master template unusable. The imprinting master template provided in Example 13 uses perfluoroalkoxy resin with a number-average molecular weight > 500,000 for the pattern layer, resulting in excessive brittleness and a shorter service life.

[0142] In Comparative Example 1, both the base layer and the pattern layer of the embossing master template are made of polytetrafluoroethylene. The resulting embossing master template has poor transparency and high adhesion to PDMS, which will cause PDMS residue during the demolding process.

[0143] The imprinting master template provided in Comparative Example 2 does not have a plasma reinforcement layer, which results in improved adhesion between the imprinting master template and PDMS compared to the imprinting master templates provided in other embodiments.

[0144] In summary, this invention designs the structure of the imprinting master template and the materials for the pattern layer and base layer. Furthermore, by using perfluoroalkoxy resin, a high-performance imprinting master template is prepared. The imprinting master template provided by this invention exhibits high rigidity, high-resolution processing capability, and good thermal stability. Simultaneously, without requiring a temporary anti-stick coating, it also possesses inertness and extremely low adhesion to PDMS, improving process integration, operational stability, template lifespan, and the repeatability and precision of nanostructure manufacturing.

[0145] The applicant declares that the detailed structural features and detailed process flow of the present invention are illustrated through the above embodiments, but the present invention is not limited to the above detailed structural features and detailed process flow, that is, it does not mean that the present invention must rely on the above detailed structural features or the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the components used in the present invention, additions of auxiliary components, selection of specific methods, equivalent substitutions of the raw materials of the product of the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An embossing master template, characterized in that, The embossing master template comprises a substrate layer, a pattern layer and a plasmonic enhancement layer arranged in sequence; The material of the substrate layer comprises a first perfluoroalkoxy resin, and the material of the pattern layer comprises a second perfluoroalkoxy resin and a filler.

2. The imprinted master template of claim 1, wherein, The number average molecular weight of the first perfluoroalkoxy resin is 100,000-200,000.

3. The imprinted master template according to claim 1 or 2, characterized in that, The number average molecular weight of the second perfluoroalkoxy resin is 200,000-500,000. Preferably, the filler comprises any one or a combination of at least two of graphite, molybdenum dioxide nanoparticles and tungsten trioxide nanoparticles. Preferably, the average particle size of the filler is ≤5 nm.

4. The imprinted master template according to any one of claims 1 to 3, wherein, The mass percentage of the filler is 0.1-5 wt% based on 100 wt% of the mass percentage of the material forming the pattern.

5. The imprinted master template according to any one of claims 1-4, wherein, The thickness of the substrate layer is ≥30 mm, and is further preferably 30-50 mm. Preferably, the thickness of the pattern layer is 2-20 mm. Preferably, the thickness of the plasmonic enhancement layer is 5-20 nm.

6. A method of producing an embossing master stamper as claimed in any one of claims 1-5, characterized in that, The preparation method comprises the following steps: (1) injection molding a material of the pattern layer on a substrate provided with a pattern, pressure holding and cooling to obtain the pattern layer; wherein the pattern on the substrate is complementary to the pattern in the pattern layer of the embossing master template; (2) injection molding a material of the substrate layer on the side of the pattern layer away from the substrate, pressure holding and cooling to obtain the substrate layer and the pattern layer in abutment; (3) under a protective atmosphere, irradiating the substrate layer and the pattern layer in abutment, then performing plasma treatment to form a plasmonic enhancement layer on the side of the pattern layer away from the substrate layer, thereby obtaining the embossing master template.

7. The production method according to claim 6, wherein The substrate provided with a pattern is prepared by the following method, which comprises the following steps: chromium plating on the substrate to obtain a chromium layer, coating photoresist on the surface of the side of the chromium layer away from the substrate, exposure and development, dry etching to form a pattern on the chromium layer which is complementary to the pattern in the pattern layer of the embossing master template, thereby completing the preparation of the substrate provided with a pattern; Preferably, the substrate comprises a quartz substrate.

8. The production method according to claim 6 or 7, characterized by, The injection molding of step (1) further comprises a pretreatment step, and the method of the pretreatment comprises first pre-drying treatment of the material of the pattern layer. Preferably, the temperature of the first pre-drying treatment is 110-130°C, and the time is 5-7 h. Preferably, the injection molding of step (1) comprises first melt plasticization and first high-pressure injection. Preferably, the temperature of the first melt plasticization is 330-370°C. Preferably, the temperature of the feeding area of the first melt plasticization is 310-330°C, the temperature of the plasticizing area is 340-360°C, and the temperature of the injection area is 350-370°C. Preferably, the pressure of the first high-pressure injection is 100-150 MPa. Preferably, the temperature of the mold used in the injection molding of step (1) is 180-230°C. Preferably, the time of the pressure holding and cooling of step (1) is 6-9 h. Preferably, the pressure holding and cooling is further followed by a demolding step.

9. The method of any one of claims 6-8, wherein, The injection molding of step (2) further comprises a pretreatment step, and the method of the pretreatment comprises second pre-drying treatment of the material of the substrate layer. Preferably, the temperature of the second pre-drying treatment is 110-130℃, and the time is 5-7 h; Preferably, the injection molding of step (2) comprises a second melt plasticizing and a second high-pressure injection; Preferably, the temperature of the second melt plasticizing is 330-370℃; Preferably, the temperature of the feeding zone of the second melt plasticizing is 310-330℃, the temperature of the plasticizing zone is 340-360℃, and the temperature of the injection zone is 350-370℃; Preferably, the pressure of the second high-pressure injection is 100-150 MPa; Preferably, the temperature of the mold used in the injection molding of step (2) is 180-230℃; Preferably, the time of the pressure-keeping cooling of step (2) is 6-9 h; Preferably, the pressure-keeping cooling is followed by a step of demolding.

10. The method of any one of claims 6-9, wherein, The protective gas comprises nitrogen; Preferably, the wavelength used in the irradiation is 280-315 nm; Preferably, the time of the irradiation is 1-2 h; Preferably, the plasma treatment is carried out in an F-based plasma atmosphere; Preferably, the time of the plasma treatment is 25-35 min.

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