Vacuum magnetic force assisted nanoimprint device

Abstract

The application discloses a vacuum magnetic force auxiliary nano-imprint device, which comprises a supporting unit, a positioning unit and a vacuum magnetic force unit. The supporting unit comprises a supporting table and a fixing block, and is used for adjusting the position of a lower substrate during imprinting. The positioning unit comprises a guide rail, a positioning block and a sliding block, and is used for adjusting the position of an upper soft film substrate during imprinting and ensuring the accuracy of imprinting. The vacuum magnetic force unit comprises a vacuum box and magnets inside and outside the vacuum box, and is used for maintaining a vacuum environment during imprinting and providing a magnetic force to control the start of a nano-imprint process. The application utilizes a vacuum magnetic force means to assist the nano-imprint process, can avoid structure defects such as collapse and insufficient filling generated by conventional nano-imprint means when processing high aspect ratio structures, and realizes reliable nano-imprint processing of high-precision high-aspect-ratio structures.

Description

Technical Field

[0001] This invention relates to the field of nanoimprint technology, and more specifically to a vacuum magnetically assisted nanoimprint device. Background Technology

[0002] With the rapid development of micro-nano fabrication technology, various micro-nano structure forming techniques are constantly emerging. Among them, nanoimprint lithography, with its high-efficiency processing capabilities and ultra-high resolution, has been widely used in fields such as micro energy storage, micro-nano optics, and flexible electronics. The basic principle of nanoimprint lithography is to use thermoplastic polymers or silicon-based materials as templates to prepare the desired micron or nanoscale structures on their surfaces, and then use high-temperature hot pressing to copy the micro-nano structures on the template onto the target material.

[0003] However, when existing nanoimprinting equipment processes high aspect ratio structures, due to the narrow and deep structural characteristics of such micro-nano structures, the air remaining in the gaps between the structures on the template cannot be completely expelled during the extremely short nanoimprinting process, resulting in structural defects such as collapse and incomplete filling of the imprinted structure. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a vacuum magnetic-assisted nanoimprinting device. This device places the entire imprinting process in a vacuum environment to avoid air bubble defects caused by air during imprinting in common imprinting equipment. At the same time, it utilizes magnetic force as the imprinting operation switch and power source in a vacuum environment, thus solving the problem of inconvenient operation in a vacuum environment.

[0005] The aforementioned vacuum magnetic-assisted nanoimprinting device includes a support unit, a positioning unit, and a vacuum magnetic unit. During operation, the device releases the magnetic switch of the vacuum magnetic unit, using the positioning and support units to ensure alignment and adhesion between the soft mold and the nanoimprinting adhesive. Magnetic force is then used to tightly press the two together, achieving the transfer of the microstructure from the soft film to the nanoimprinting adhesive.

[0006] The support unit includes a support platform and a fixing block; the fixing block is placed on the support platform and their sides overlap; the support unit is used to adjust the position of the substrate during imprinting.

[0007] The positioning unit includes a guide rail, a positioning block, and a slider. The positioning block is located on the upper surface of the guide rail and its sides overlap. The outer protrusion of the slider overlaps with the inner wall groove of the guide rail and the positioning block. During operation, the positioning unit aligns the slider with the guide rail through the positioning block, and then releases the magnetic switch to allow the slider to move vertically downward along the groove of the positioning block and the guide rail under the combined action of magnetic force and gravity. The positioning unit is used to adjust the position of the upper soft film substrate during imprinting and to ensure imprinting accuracy.

[0008] The vacuum magnetic unit includes a vacuum chamber and magnets inside and outside it. The inner and outer magnets are placed on the inner and outer sides of the upper wall of the vacuum chamber, respectively. During operation, the vacuum magnetic unit removes the magnet outside the vacuum chamber, allowing the inner magnet and slider to move vertically downward along the guide rail, and finally presses the soft mold tightly against the adhesive substrate. The vacuum magnetic unit is used to maintain the vacuum environment during imprinting and to provide magnetic force to control the start of the nanoimprinting process.

[0009] In some embodiments, the support unit further includes a heating stage, on which a lower substrate is placed, and a support platform is connected below the heating stage. The vertical position of the heating stage is adjusted by the height of the support platform, and a fixing block is connected to the side of the heating stage. The horizontal position of the heating stage is positioned by the fixing block.

[0010] In some embodiments, the guide rail and positioning block of the positioning unit are integrated or separate, and the upper soft film substrate is fixedly connected below the slider. The movement of the slider is limited by the cooperation of the guide rail and the positioning block.

[0011] In some embodiments, the vacuum magnetic unit further includes a vacuum pump and a controller. The vacuum pump is connected to the vacuum chamber via a gas path, and the controller is fixedly connected to the vacuum chamber. The controller can adjust the gas pressure and vacuum level inside the vacuum chamber.

[0012] In some embodiments, the above-described apparatus further includes an ultraviolet irradiation unit for curing nanoimprint adhesive.

[0013] In some embodiments, the method of using the above-described vacuum magnetically assisted nanoimprinting device includes:

[0014] S1: Place the hot stage on the support platform of the support unit inside the vacuum chamber, with its side in contact with the fixing block to fix the hot stage; fix the substrate with nano-imprint adhesive on the lower substrate, with the nano-imprint adhesive facing upwards, and place the lower substrate on the upper surface of the hot stage; fix the transparent substrate with soft film on the upper soft film substrate, with the soft film facing downwards, and fix the upper soft film substrate on the slider of the positioning unit; place the inner and outer magnets of the vacuum magnetic unit on the inner and outer sides of the upper wall of the vacuum chamber respectively, and fix the inner and outer magnets by magnetic force, and fix the slider with the upper soft film substrate below the inner magnet; fit the edge of the slider with the positioning block to achieve the positioning of the slider, and adjust the position of the lower substrate so that the positions of the upper soft film substrate and the lower substrate correspond;

[0015] S2: The vacuum chamber is kept at a vacuum level of 1~4×10-2 Pa by the vacuum pump and controller; the magnet outside the vacuum chamber is removed, and the slider with the upper soft film substrate is moved downward by the positioning block and the guide rail. During the movement, the soft film comes into contact with the nanoimprint adhesive, and the structure on the soft film is copied to the nanoimprint adhesive.

[0016] S3: Use the vacuum pump and controller to restore the standard atmospheric pressure in the vacuum chamber, open the vacuum chamber, and take out the hot stage and the lower substrate, upper soft film substrate, slider, and inner magnet placed on it.

[0017] S4: Remove the fixedly connected slider and inner magnet, align the ultraviolet irradiation unit with the upper soft film substrate, and use the ultraviolet light emitted by it to pass through the upper soft film substrate and transparent substrate to cure the nano-imprint adhesive.

[0018] S5: Move the upper soft film substrate upward to separate the soft film from the nano-imprint adhesive, completing the demolding process.

[0019] Furthermore, the aforementioned hot plate is maintained at 80~120℃ during operation. The material of the lower substrate is one of hard magnetic materials such as alloy permanent magnet material and ferrite permanent magnet material. The upper soft film substrate has a hollow structure with light transmission in the middle area. The material of the upper soft film substrate is one of hard magnetic materials such as alloy permanent magnet material and ferrite permanent magnet material.

[0020] Furthermore, the aforementioned magnet is one of hard magnetic materials such as alloy permanent magnet material and ferrite permanent magnet material; the nanoimprint adhesive is one of SUN-1621N-500cp, PS01 or PS02; the soft film has a high aspect ratio structure, which is a microstructure with a width-to-depth ratio greater than 3:1 and a structural accuracy of 100 nm to 10 μm; and the soft film material is one of PDMS, PMMA, PVA, PET, PVC, PTFE, PC or PUA.

[0021] Furthermore, the ultraviolet light emitted by the aforementioned ultraviolet irradiation unit is g-line ultraviolet light or i-line ultraviolet light, the irradiation method of the ultraviolet irradiation unit is parallel light irradiation, and the irradiation time of the ultraviolet irradiation unit is 20 s to 2 min, so that during the curing process of the nanoimprint adhesive, the upper soft film substrate and the lower substrate are attracted by magnetic force to keep the soft film and the nanoimprint adhesive in close contact at all times.

[0022] Furthermore, the method of moving the upper soft film substrate upwards described above is either manually controlled or mechanically operated.

[0023] The vacuum magnetically assisted nanoimprinting device proposed in this invention places the entire imprinting process in a vacuum environment using a vacuum chamber and vacuum pump, eliminating air bubble defects introduced during the imprinting process. Simultaneously, a magnet acts as a release switch; when the external magnet is removed, the internal magnet, along with the slider, soft film substrate, and soft film, falls vertically along a guide rail. Upon contact with the substrate coated with nanoimprinting adhesive, the attraction between the internal magnet and the lower substrate tightly bonds the soft film to the substrate, achieving microstructure transfer. The imprinting force can be controlled by adjusting the structural dimensions of the internal magnet. Addressing the problems existing in current nanoimprinting equipment for processing high aspect ratio structures, this invention utilizes a vacuum environment and magnetically assisted imprinting to effectively solve problems such as air bubble defects that occur during nanoimprinting preparation, resulting in high aspect ratio structures with complete morphology. Attached Figure Description

[0024] To make the content of this invention clearer, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0025] Figure 1 This is a schematic diagram of the support unit structure of a vacuum magnetically assisted nanoimprinting device provided by the present invention.

[0026] Figure 2 This is a schematic diagram of the positioning unit structure of a vacuum magnetically assisted nanoimprinting device provided by the present invention.

[0027] Figure 3 This is a schematic diagram of the vacuum magnetic unit structure of a vacuum magnetic assisted nanoimprinting device provided by the present invention.

[0028] Figure 4 The working process of a vacuum magnetically assisted nanoimprinting device provided by the present invention.

[0029] Figure 5 The imprinting results are from existing nanoimprinting equipment.

[0030] Figure 6 The imprinting result of a vacuum magnetically assisted nanoimprinting device provided by the present invention.

[0031] Figure label:

[0032] 1 is a support unit, 11 is a support platform, and 12 is a fixing block;

[0033] 2 is the positioning unit, 21 is the guide rail, 22 is the positioning block, and 23 is the slider;

[0034] 3 is a vacuum magnetic unit, 31 is a vacuum box, and 32 is a magnet;

[0035] 4 is a hot plate;

[0036] 5 is the lower substrate;

[0037] 6 represents the upper flexible film substrate;

[0038] 7 is the ultraviolet irradiation unit. Detailed Implementation

[0039] To gain a more detailed understanding of the features and technical content of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the specification, claims, and accompanying drawings of the embodiments of this invention, the terms "first," "second," etc., are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that, where appropriate, the data represented by these terms can be interchanged to adapt to different application scenarios of the embodiments of this invention. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to express a non-exclusive inclusion relationship, meaning that in addition to the explicitly listed elements, other unlisted elements may also be included.

[0041] In embodiments of the present invention, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., are used to indicate orientation or positional relationships based on the accompanying drawings. These terms are intended to more clearly describe the embodiments of the present invention and their specific application scenarios, and are not intended to limit the related devices, elements, or components to following a specific orientation or construction method. Furthermore, these terms may have other meanings besides indicating orientation or positional relationships; for example, "upper" may indicate a dependency or connection relationship in some contexts. Those skilled in the art should be able to accurately understand the actual meaning of these terms in the embodiments of the present invention according to the specific context.

[0042] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly in the embodiments of this invention. Specifically, "connect" not only covers fixed and detachable connections but also includes integral structures; it can be a mechanical or electrical connection, a direct connection or an indirect connection through an intermediate medium, or even refer to direct communication within two devices, components, or parts. Similarly, "set up" and "fix" should be interpreted flexibly according to the specific context. Those skilled in the art can accurately determine the specific meaning of these terms in the embodiments of this invention based on the specific circumstances.

[0043] Combination Figures 1-3 As shown in the figure, this invention proposes a vacuum magnetic assisted nanoimprinting device, including a support unit 1, a positioning unit 2, and a vacuum magnetic unit 3. The support unit 1 includes a support platform 11 and a fixing block 12, used to adjust the position of the lower substrate during imprinting. The positioning unit 2 includes a guide rail 21, a positioning block 22, and a slider 23, used to adjust the position of the upper soft film substrate during imprinting and to ensure imprinting accuracy. The vacuum magnetic unit 3 includes a vacuum box 31 and magnets 32 inside and outside it, used to maintain the vacuum environment during imprinting and to provide magnetic force to control the start of the nanoimprinting process.

[0044] Furthermore, the support unit 1 also includes a heating stage, on which a lower substrate is placed. A support platform 11 is connected below the heating stage. The vertical position of the heating stage is adjusted by the height of the support platform 11. A fixing block 12 is connected to the side of the heating stage, and the horizontal position of the heating stage is positioned by the fixing block 12.

[0045] Furthermore, the guide rail 21 and positioning block 22 of the positioning unit 2 are either integrated or separate, and the upper soft film substrate 6 is fixedly connected to the lower part of the slider 23. The movement of the slider 23 is limited by the cooperation of the guide rail 21 and the positioning block 22.

[0046] Furthermore, the vacuum magnetic unit 3 also includes a vacuum pump and a controller. The vacuum pump is connected to the vacuum chamber 31 through a gas path, and the controller is fixedly connected to the vacuum chamber 31. The controller can adjust the gas pressure and vacuum level inside the vacuum chamber 31.

[0047] Furthermore, the vacuum magnetically assisted nanoimprinting device obtained in this embodiment of the invention also includes an ultraviolet irradiation unit 7, which is used to cure the nanoimprinting adhesive.

[0048] Combination Figure 4 As shown in the embodiment of the present invention, the method of using a vacuum magnetically assisted nanoimprinting device includes:

[0049] S1: Place the heating stage on the support platform 11 of the support unit 1 inside the vacuum chamber 31, with its side in contact with the fixing block 12 to fix the heating stage. Connect the power supply to the heating stage and set the temperature to 110℃. Fix the substrate with nano-imprint adhesive onto the lower substrate 5. The lower substrate 5 is a hard magnetic ferrite in ferrite permanent magnet material. Place the lower substrate 5 on the upper surface of the heating stage with the nano-imprint adhesive facing upwards. Fix the pre-treated transparent substrate with PDMS soft template onto the upper soft film substrate 6 with heat release tape. Fix the upper soft film substrate 6 onto the slider 23 of the positioning unit 2 with the soft film facing downwards. Place the inner and outer magnets 32 of the vacuum magnetic unit 3 on the inner and outer sides of the upper wall of the vacuum chamber 31, respectively. Fix the inner and outer magnets 32 by magnetic force. Fix the slider 23 with the upper soft film substrate 6 below the inner magnet 32. Attach the edge of the slider 23 to the positioning block 22 to position the slider 23, so that the upper soft film substrate 6 and the lower substrate 5 are in corresponding positions.

[0050] S2: The vacuum chamber 31 is maintained at a vacuum level of 4×10-2 Pa by the vacuum pump and controller. The external magnet 32 ​​of the vacuum chamber 31 is removed, and the slider 23 with the upper soft film substrate 6 is limited by the positioning block 22 and the guide rail 21 to move downward. During the movement, the soft film comes into contact with the nanoimprint adhesive, and the structure on the soft film is replicated onto the nanoimprint adhesive by the attraction between the magnet 32 ​​and the lower substrate 5.

[0051] S3: Restore the standard atmospheric pressure inside the vacuum chamber 31 by using a vacuum pump and controller, open the vacuum chamber 31, and take out the hot stage 4 and the lower substrate 5, upper soft film substrate 6, slider 23, and inner magnet 32 ​​placed on it.

[0052] S4: Remove the fixedly connected slider 23 and inner magnet 32, align the ultraviolet irradiation unit 7 with the upper soft film substrate 6, and use the g-ray ultraviolet light emitted by it to irradiate the nanoimprint adhesive 60 s through the hollowed-out upper soft film substrate 6 and the transparent substrate, so that the nanoimprint adhesive is cured. During this process, the upper soft film substrate 6 and the lower substrate 5 are attracted by magnetic force to keep the soft film and the nanoimprint adhesive in close contact at all times.

[0053] S5: Move the upper soft film substrate 6 upward to separate the soft film from the nano-imprint adhesive and complete the demolding process.

[0054] The vacuum magnetically assisted nanoimprinting apparatus of this invention places the entire imprinting process in a vacuum environment using a vacuum chamber and vacuum pump, eliminating air bubble defects caused by air during the imprinting process. Simultaneously, a magnet is used as a release switch; when the external magnet is removed, the internal magnet, along with the slider, soft film substrate, and soft film, falls vertically along the guide rail. Upon contact with the substrate coated with nanoimprinting adhesive, the attraction between the internal magnet and the lower substrate tightly bonds the soft film to the substrate, achieving microstructure transfer. The imprinting force can be controlled by adjusting the structural dimensions of the internal magnet. Addressing the problems existing in current nanoimprinting equipment for processing high aspect ratio structures, this invention utilizes a vacuum environment and magnetically assisted imprinting to effectively solve problems such as air bubble defects that occur during nanoimprinting preparation of this structure, resulting in a high aspect ratio structure with a complete morphology.

[0055] The above embodiments are merely examples to clearly illustrate the present invention and are not intended to limit the implementation. Those skilled in the art should understand that the scope of the present invention includes, but is not limited to, the above embodiments. Various changes made to the present invention in other forms without departing from the spirit or basic characteristics of the present invention are all included within the protection scope of the present invention.

Claims

1. A vacuum magnetically assisted nanoimprinting device, characterized in that, The device includes a support unit, a positioning unit, and a vacuum magnetic unit. The outer side of the support unit is connected to the inner side of the positioning unit, and both are placed on the inner bottom surface of the vacuum magnetic unit. The device places the entire imprinting process in a vacuum environment to avoid structural defects caused by air bubbles during imprinting. Simultaneously, the magnetic force acts as both the imprinting switch and the power source in the vacuum environment. During operation, the device releases the magnetic switch of the vacuum magnetic unit, using the positioning unit and support unit to ensure alignment and adhesion between the soft mold and the nano-imprinting adhesive. The magnetic force then tightly presses the two together, achieving the transfer of the microstructure from the soft film to the nano-imprinting adhesive. The support unit includes a support platform and a fixing block; the fixing block is placed on the support platform and their sides overlap; the support unit is used to adjust the position of the lower substrate during imprinting; The positioning unit includes a guide rail, a positioning block, and a slider. The positioning block is located on the upper surface of the guide rail and its sides overlap. The outer protrusion of the slider overlaps with the inner wall groove of the guide rail and the positioning block. During operation, the positioning unit aligns the slider with the guide rail through the positioning block, and then releases the magnetic switch to allow the slider to move vertically downward along the groove of the positioning block and the guide rail under the combined action of magnetic force and gravity. The positioning unit is used to adjust the position of the upper soft film substrate during imprinting and to ensure imprinting accuracy. The vacuum magnetic unit includes a vacuum chamber and magnets inside and outside it; the inner and outer magnets are respectively placed on the inner and outer sides of the upper wall of the vacuum chamber; during operation, the vacuum magnetic unit removes the magnet outside the vacuum chamber, allowing the inner magnet and slider to move vertically downward along the guide rail, and finally presses the soft mold tightly against the adhesive substrate; the vacuum magnetic unit is used to maintain the vacuum environment during imprinting and to provide magnetic force to control the start of the nanoimprinting process.

2. The vacuum magnetic-assisted nanoimprinting device according to claim 1, characterized in that, The support unit also includes a heating platform, on which a lower base plate is placed. A support platform is connected below the heating platform. The vertical position of the heating platform is adjusted by the height of the support platform. A fixing block is connected to the side of the heating platform, and the horizontal position of the heating platform is positioned by the fixing block.

3. The vacuum magnetic-assisted nanoimprinting device according to claim 1, characterized in that, The guide rail and positioning block of the positioning unit are either integrated or separate. The upper soft film substrate is fixedly connected to the bottom of the slider, and the movement of the slider is limited by the cooperation of the guide rail and the positioning block.

4. The vacuum magnetically assisted nanoimprinting device according to claim 1, characterized in that, The vacuum magnetic unit also includes a vacuum pump and a controller. The vacuum pump is connected to the vacuum chamber via a gas path, and the controller is fixedly connected to the vacuum chamber. The controller can adjust the gas pressure and vacuum level inside the vacuum chamber.

5. The vacuum magnetically assisted nanoimprinting device according to claim 1, characterized in that, The device also includes an ultraviolet irradiation unit for curing nanoimprint adhesive.

6. A method of using the vacuum magnetically assisted nanoimprinting device according to any one of claims 1-5, characterized in that, The method of use includes: S1: Place the hot stage on the support platform of the support unit inside the vacuum chamber, with its side in contact with the fixing block to fix the hot stage; fix the substrate with nano-imprint adhesive on the lower substrate, with the nano-imprint adhesive facing upwards, and place the lower substrate on the upper surface of the hot stage; fix the transparent substrate with soft film on the upper soft film substrate, with the soft film facing downwards, and fix the upper soft film substrate on the slider of the positioning unit; place the inner and outer magnets of the vacuum magnetic unit on the inner and outer sides of the upper wall of the vacuum chamber respectively, and fix the inner and outer magnets by magnetic force, and fix the slider with the upper soft film substrate below the inner magnet; fit the edge of the slider with the positioning block to achieve the positioning of the slider, so that the upper soft film substrate and the lower substrate are in corresponding positions; S2: The vacuum chamber is maintained at a vacuum level of 1×10⁻⁶ using a vacuum pump and controller. -2 ~4×10 -2 Pa; Remove the magnet outside the vacuum chamber, so that the slider with the upper soft film substrate moves downward under the limit of the positioning block and the guide rail. During the movement, the soft film comes into contact with the nanoimprint adhesive, and the structure on the soft film is copied onto the nanoimprint adhesive. S3: Use the vacuum pump and controller to restore the standard atmospheric pressure in the vacuum chamber, open the vacuum chamber, and take out the hot stage and the lower substrate, upper soft film substrate, slider, and inner magnet placed on it. S4: Remove the fixedly connected slider and inner magnet, align the ultraviolet irradiation unit with the upper soft film substrate, and use the ultraviolet light emitted by it to pass through the upper soft film substrate and transparent substrate to cure the nano-imprint adhesive. S5: Move the upper soft film substrate upward to separate the soft film from the nano-imprint adhesive, completing the demolding process.

7. The method of using the vacuum magnetic-assisted nanoimprinting device according to claim 6, characterized in that, The heating stage is maintained at 80~120℃ during operation. The material of the lower substrate is either an alloy permanent magnet material or a ferrite permanent magnet material. The upper soft film substrate has a hollow structure with light transmission in the middle area. The material of the upper soft film substrate is either an alloy permanent magnet material or a ferrite permanent magnet material.

8. The method of using the vacuum magnetic-assisted nanoimprinting device according to claim 6, characterized in that, The magnet is one of alloy permanent magnet material and ferrite permanent magnet material. The soft film has a high aspect ratio structure. The high aspect ratio structure is a microstructure with a width-to-depth ratio greater than 3:1 and a structural accuracy of 100 nm to 10 μm. The material of the soft film is one of PDMS, PMMA, PVA, PET, PVC, PTFE, PC or PUA.

9. The method of using the vacuum magnetic-assisted nanoimprinting device according to claim 6, characterized in that, The ultraviolet light emitted by the ultraviolet irradiation unit is g-line ultraviolet light or i-line ultraviolet light. The irradiation method of the ultraviolet irradiation unit is parallel light irradiation. The irradiation time of the ultraviolet irradiation unit is 20 s to 2 min. During the curing process of the nanoimprint adhesive, the upper soft film substrate and the lower substrate are attracted by magnetic force to keep the soft film and the nanoimprint adhesive in close contact at all times.

10. The method of using the vacuum magnetically assisted nanoimprinting device according to claim 6, characterized in that, The upward movement of the upper soft film substrate is achieved through manual control or mechanized operation.

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