Electron beam lithography micro-nano structure processing method, device, anti-counterfeiting mark and reflective grating

Abstract

The application relates to an electron beam lithography micro-nano structure processing method and device, an anti-fake mark and a reflection grating. The method comprises the following steps: preparing an acrylic substrate; obtaining a design structure; and irradiating the acrylic substrate by using an electron beam according to the design structure, so as to obtain a micro-nano structure with the design structure. The acrylic material is subjected to micro-nano structure processing, the process of electron beam lithography micro-nano structure processing is simplified, and the material cost and the labor cost can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro-nano processing, and in particular to an electron beam lithography micro-nano structure processing method and device, an anti-counterfeiting mark and a reflective grating. BACKGROUND

[0002] Micro-nano processing is an advanced processing technology. The technology is a technology for transferring micro-nano structures on a template to a material to be processed by a light beam, and is an important processing means in the fields of microelectronics and materials.

[0003] In conventional electron beam lithography micro-nano structure processing, a series of steps including substrate processing, glue coating, exposure, development, etching or film plating are usually required. In the electron beam lithography process, the selection of electron beam resist is very important, and a resist with very good molecular weight consistency is often required to better maintain the process stability of electron beam lithography. Therefore, the substrate and resist in the process will cause a large cost consumption.

[0004] It can be seen that the electron beam lithography micro-nano processing method in the prior art has high cost and process stability dependent on the consistency of raw materials. SUMMARY

[0005] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides an electron beam lithography micro-nano structure processing method, device, anti-counterfeiting mark and reflective grating.

[0006] In a first aspect, the present application provides an electron beam lithography micro-nano structure processing method, the method comprising:

[0007] preparing an acrylic substrate;

[0008] obtaining a design structure;

[0009] irradiating the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure.

[0010] Optionally, the preparation of the acrylic substrate comprises:

[0011] plating a metal layer on the irradiation surface of an acrylic substrate to prepare the acrylic substrate, wherein the acrylic substrate comprises an irradiation surface and a bottom surface, and the irradiation surface and the bottom surface of the acrylic substrate are oppositely arranged.

[0012] Optionally, the irradiation of the acrylic substrate with an electron beam according to the design structure comprises:

[0013] dividing the design structure into a dot matrix comprising a plurality of processing points;

[0014] obtaining a processing sequence and a processing depth of each processing point according to the design structure;

[0015] According to the machining point, an irradiation point on the acrylic substrate is obtained;

[0016] According to the machining sequence, an irradiation sequence on the acrylic substrate is obtained;

[0017] According to the irradiation sequence, the acrylic substrate is irradiated by the electron beam according to the machining depth at the irradiation point.

[0018] Optionally, according to the design structure, the machining depth of each machining point is obtained, including:

[0019] Depth information contained in each machining point of the design structure is obtained;

[0020] According to the depth information, the machining depth of each machining point is obtained.

[0021] Optionally, according to the design structure, the machining depth of each machining point is obtained, including:

[0022] Color information contained in each machining point of the design structure is obtained;

[0023] The machining depth corresponding to the color information contained in each machining point is obtained.

[0024] Optionally, the irradiation by the electron beam according to the machining depth includes:

[0025] An irradiation dose corresponding to the machining depth is obtained;

[0026] The electron beam is irradiated according to the irradiation dose.

[0027] Optionally, the irradiation dose corresponding to the machining depth is obtained, including:

[0028] An irradiation intensity within a preset time period is obtained; and / or

[0029] An irradiation time period under a preset irradiation intensity is obtained.

[0030] In a second aspect, an electron beam lithography micro-nano structure machining device is provided, and the device includes:

[0031] A substrate preparation unit is configured to prepare an acrylic substrate;

[0032] A structure design unit is configured to obtain a design structure;

[0033] A machining unit is configured to irradiate the acrylic substrate by an electron beam according to the design structure, so as to obtain a micro-nano structure with the design structure.

[0034] In a third aspect, there is provided a security mark, prepared by the method of any one of the above.

[0035] In a fourth aspect, there is provided a reflective grating, prepared by the method of any one of the above.

[0036] The present application relates to an electron beam lithography micro-nano structure processing method and device, a security mark and a reflective grating. The method comprises: preparing an acrylic substrate; obtaining a design structure; and irradiating the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure. In the method of the present application, the acrylic substrate is irradiated with an electron beam to obtain a micro-nano structure with the design structure, without the need for coating a resist on the substrate, and without the need for steps such as gluing and developing, thereby simplifying the process of traditional electron beam lithography micro-nano structure processing. In addition, without the need for additional gluing and developing, and without the need for coating a resist, the material cost and labor cost can be reduced. At the same time, since the electron beam lithography of the acrylic material is the change in the height of the surface of the acrylic material caused by the change in the density of the acrylic material, the micro-nano structure processed by the method of the present application has good continuity and high resolution. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0039] Figure 1 A flowchart of the electron beam lithography micro-nano structure processing method of the present application is shown.

[0040] Figure 2 A schematic diagram of the electron beam lithography micro-nano structure processing of the reflective structure of the present application is shown.

[0041] Figure 3 A schematic diagram of the design structure of the present application is shown.

[0042] Figure 4 A structural block diagram of the electron beam lithography micro-nano structure processing device of the present application is shown.

[0043] Figure 5 A schematic diagram of a security mark of the present application is shown.

[0044] Figure 6 Fig. 1 is a schematic diagram of an electron beam lithography micro-nano structure processing system according to an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0046] The embodiments of the present application provide an electron beam lithography micro-nano structure processing method, as shown in the method comprises the following steps. Figure 1

[0047] Step 110, preparing a PMMA substrate;

[0048] Step 120, obtaining a design structure;

[0049] Step 130, according to the design structure, using an electron beam to irradiate the PMMA substrate to obtain a micro-nano structure with the design structure.

[0050] The basic principle of electron beam lithography is that through irradiation of an electron beam, the molecular chains of a resist are broken or bonded, so as to change the solubility of the resist in a developing solution, so as to achieve the effect of distinguishing the exposed area from the non-exposed area. PMMA (polymethyl methacrylate) is the most common positive resist in electron beam lithography, which will be converted from a long-chain molecule to a short-chain molecule after irradiation of an electron beam, so as to increase the solubility in the developing solution. Through experiments, after the PMMA is converted from a long-chain molecule to a short-chain molecule, the density will change, so that the difference between the exposed area and the non-exposed area can be shown before developing. The height of the area irradiated by the electron beam will be significantly smaller than that of the non-exposed area. Moreover, the shrinkage depth of PMMA and the dose are linearly related within a certain range, and with the increase of the exposure dose, the processing depth also increases, so that the processing depth can be accurately controlled by controlling the exposure dose.

[0051] PMMA material is also PMMA in nature, so the PMMA material can also be converted from a long-chain molecule to a short-chain molecule after irradiation of an electron beam, and can be used as a material for electron beam lithography micro-nano structure processing. In fact, the method of the present application can be applied to other PMMA, and can also be applied to other materials that will produce obvious deformation due to irradiation of an electron beam.

[0052] ​The method of the embodiment of the present application adopts electron beam irradiation on the acrylic substrate to obtain the micro-nano structure with the design structure, without coating resist on the substrate, without coating glue, developing and other steps, and simplifies the process of traditional electron beam lithography micro-nano structure processing. In addition, without additional coating of glue and developing, and without coating of resist, the material cost and labor cost can be reduced.

[0053] Meanwhile, since the electron beam lithography on the acrylic material is the height change of the surface of the acrylic material caused by the density change of the acrylic material, the micro-nano structure processed by the method of the embodiment of the present application has good continuity and high resolution. It is verified by experiments that the resolution of the processed plane can reach below 10 nm, and the resolution of the processed depth can exceed 1 nm.

[0054] The method of the embodiment of the present application can process the micro-nano structure of the transmission type structure, for example Figure 1 The method of the embodiment of the present application can also process the micro-nano structure of the reflection type structure, at this time, a metal layer needs to be plated.

[0055] In the embodiment of the present application, the design structure can be various patterns, characters, or anti-counterfeiting marks, and the like, which will not be described here.

[0056] In the embodiment of the present application, the preparation of the acrylic substrate can include cutting, slicing and the like of the acrylic base material, and can also include surface polishing and the like. The irradiation surface and the bottom surface of the acrylic substrate need to ensure a certain flatness, and generally the surface of the acrylic substrate is relatively flat and can meet the processing requirements, at this time, the irradiation surface and the ground do not need to be polished again.

[0057] In the embodiment of the present application, the preparation of the acrylic substrate includes:

[0058] A metal layer is plated on the irradiation surface of the acrylic base material to prepare the acrylic substrate, wherein the acrylic base material includes an irradiation surface and a bottom surface, and the irradiation surface and the bottom surface of the acrylic base material are oppositely arranged.

[0059] Figure 2 Fig. 4 shows a schematic diagram of the electron beam lithography micro-nano structure processing of the reflection type structure of the embodiment of the present application. Figure 2 Fig. 1 shows an acrylic base material, Figure 2 Fig. 2 shows plating of a metal layer on the irradiation surface, Figure 2 Fig. 3 shows the micro-nano structure after processing.

[0060] In the embodiment of the present application, in step 130, the electron beam irradiation on the acrylic substrate according to the design structure includes:

[0061] The design structure is divided into a plurality of processing points;

[0062] According to the design structure, the machining sequence and the machining depth of each machining point are obtained.

[0063] According to the machining point, the irradiation point on the acrylic substrate is obtained.

[0064] According to the machining sequence, the irradiation sequence on the acrylic substrate is obtained.

[0065] According to the irradiation sequence, the irradiation is performed on the irradiation point of the acrylic substrate by using the electron beam according to the machining depth.

[0066] Figure 3 The design structure of the embodiment of the present application is shown in the schematic diagram, Figure 3 (a) is a design structure, Figure 3 (b) is a dot matrix divided according to the design structure.

[0067] The machining sequence can be in row order, column order, or alphabetical order, for example Figure 3 In which E is processed first, then B, and finally L.

[0068] In the embodiment of the present application, according to the design structure, the machining depth of each machining point is obtained, including:

[0069] The depth information contained in each machining point of the design structure is obtained.

[0070] According to the depth information, the machining depth of each machining point is obtained.

[0071] In the embodiment of the present application, according to the design structure, the machining depth of each machining point is obtained, including:

[0072] The color information contained in each machining point of the design structure is obtained.

[0073] The machining depth corresponding to the color information contained in each machining point is obtained.

[0074] The acrylic material / acrylic substrate itself has very good light transmittance and is transparent, and even after e-book irradiation, it cannot directly carry color. The surface of the light acrylic substrate after electron beam irradiation is different in height, and the refractive index of light of different wavelengths is also different, so the acrylic substrate after electron beam lithography can interfere in the area with height changes when light transmits, thereby presenting different colors to the outside.

[0075] Therefore, in the method of the embodiment of the present application, different color information corresponds to different machining depths.

[0076] In the embodiment of the present application, the processing depth can be determined according to the depth information in the design structure, or can be determined according to the color information, and can also be determined according to the color and depth information together.

[0077] In the embodiment of the present application, the irradiation by the electron beam according to the processing depth comprises:

[0078] Obtaining an irradiation dose corresponding to the processing depth;

[0079] Irradiating by the electron beam according to the irradiation dose.

[0080] In the embodiment of the present application, the irradiation dose corresponding to the processing depth is obtained, comprising:

[0081] Obtaining an irradiation intensity within a preset time length; and / or

[0082] Obtaining an irradiation time length under a preset irradiation intensity.

[0083] In the embodiment of the present application, the processing depth can be controlled by controlling the irradiation intensity and / or the irradiation time length, so that the design structure on the acrylic substrate presents different patterns and colors.

[0084] The method of the embodiment of the present application processes the acrylic material by electron beam lithography micro-nano structure, simplifies the process of traditional electron beam lithography micro-nano structure, can reduce the material cost and labor cost, and has good continuity and high resolution.

[0085] As shown in Figure 4 The embodiment of the present application also provides an electron beam lithography device micro-nano structure processing equipment, the equipment comprises:

[0086] A substrate preparation unit 410 is configured to prepare an acrylic substrate.

[0087] A structure design unit 420 is configured to obtain a design structure.

[0088] A processing unit 430 is configured to irradiate the acrylic substrate by an electron beam according to the design structure, so as to obtain a micro-nano structure with the design structure.

[0089] In the embodiment of the present application, the substrate preparation unit 410 is further configured to:

[0090] A metal layer is plated on the irradiation surface of the acrylic substrate to prepare the acrylic substrate, wherein the acrylic substrate comprises an irradiation surface and a bottom surface, and the irradiation surface and the bottom surface of the acrylic substrate are oppositely arranged.

[0091] In the embodiment of the present application, the processing unit 430 is further configured to:

[0092] divide the design structure into a plurality of processing points;

[0093] According to the design structure, obtain the processing sequence and the processing depth of each processing point;

[0094] According to the processing point, obtain the irradiation point on the acrylic substrate;

[0095] According to the processing sequence, obtain the irradiation sequence on the acrylic substrate;

[0096] According to the irradiation sequence, irradiate the irradiation point on the acrylic substrate by using the electron beam according to the processing depth.

[0097] In the embodiment of the present application, the processing unit 430 is further used for:

[0098] Obtain the depth information contained in each processing point of the design structure;

[0099] According to the depth information, obtain the processing depth of each processing point.

[0100] In the embodiment of the present application, the processing unit 430 is further used for:

[0101] Obtain the color information contained in each processing point of the design structure;

[0102] Obtain the processing depth corresponding to the color information contained in each processing point.

[0103] In the embodiment of the present application, the processing unit 430 is further used for:

[0104] Obtain the irradiation dose corresponding to the processing depth;

[0105] According to the irradiation dose, irradiate by using the electron beam.

[0106] In the embodiment of the present application, the processing unit 430 is further used for:

[0107] Obtain the irradiation intensity within a preset time length; and / or

[0108] Obtain the irradiation time length under a preset irradiation intensity.

[0109] The device of the embodiment of the present application carries out electron beam lithography micro-nano structure processing on the acrylic material, simplifies the process of traditional electron beam lithography micro-nano structure processing, can reduce the material cost and the labor cost, and has good continuity and high resolution.

[0110] The embodiment of the present application further provides a security mark, which applies the method as described above.

[0111] Figure 5The diagram shown is a schematic representation of an anti-counterfeiting mark according to an embodiment of the present invention. Figure 5 As shown, after electron beam lithography is used to fabricate micro / nano structures using the method described above, a white screen 520 can be placed behind the anti-counterfeiting mark 510 for easy observation. When the anti-counterfeiting mark is illuminated by a white light source 530, the pattern of the anti-counterfeiting mark can be displayed on the white screen 520. The anti-counterfeiting mark can be any pattern containing depth and color information.

[0112] In this embodiment of the invention, since the molecular weight of the acrylic substrate varies greatly between batches, the processing depth and the color also differ. Therefore, the product batches can be reasonably controlled to achieve the purpose of being almost impossible to imitate, thereby enabling the low-cost processing of anti-counterfeiting structures with excellent anti-counterfeiting performance.

[0113] This invention also provides a reflective grating, which applies the method described above.

[0114] Before processing, the reflective grating of this invention needs to be coated with a metal film on the irradiation surface.

[0115] The thickness of the metal film is typically on the order of 200nm-1μm. After coating, the acrylic substrate is opaque and the coating surface is mirror-like.

[0116] In this embodiment of the invention, the structure of the reflective grating can be referred to Figure 2 The grating has a serrated structure with varying heights, but it is not limited to serrations. The height of a single serration is usually on the order of hundreds of nanometers, and the width is on the order of micrometers to hundreds of nanometers.

[0117] In this embodiment of the invention, the reflective grating is already formed after the electron beam photolithography on the acrylic substrate, eliminating the need for development and coating steps as in conventional electron beam photolithography methods. This saves labor and material costs and simplifies the processing procedure.

[0118] This invention also provides an electron beam lithography micro / nano structure fabrication system, such as... Figure 6 As shown, the electron beam lithography micro-nano structure processing system includes an electron beam processing device 610, a pattern generator 620, a vacuum system 640, and a software system 630, which can perform electron beam lithography micro-nano structure processing on an acrylic substrate 650.

[0119] Figure 1 This is a schematic flowchart of a micro / nano structure fabrication method in one embodiment. It should be understood that, although... Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders.Figure 1 At least one of the steps in the above-mentioned embodiments can include a plurality of sub-steps or a plurality of stages, which are not necessarily performed at the same time, but can be performed at different times, and the order of the execution of the sub-steps or stages is not necessarily sequential, but can be performed alternately or in rotation with other steps or sub-steps or stages of other steps.

[0120] It can be understood by those skilled in the art that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing relevant hardware, and the program can be stored in a non-volatile computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments of the method. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0121] It should be noted that, in this document, relational terms such as "first" and "second", and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0122] The foregoing is considered as illustrative only of the principles of the application. Numerous modifications and changes will readily occur to those skilled in the art, and it is intended to embrace all such modifications and changes that fall within the scope of the application. Accordingly, the application is not to be restricted in scope to the specific embodiments disclosed herein but is to be accorded the full scope that the principles and novel features request appropriately granted.

Claims

1. An electron beam lithography micro-nano structure processing method, characterized in that, The method comprises: preparing an acrylic substrate; obtaining a design structure; irradiating the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure; the acrylic substrate preparation comprises: plating a metal layer on the irradiation surface of an acrylic substrate to prepare the acrylic substrate, wherein the acrylic substrate comprises an irradiation surface and a bottom surface, and the irradiation surface and the bottom surface of the acrylic substrate are oppositely arranged.

2. The method of claim 1, wherein, The irradiation of the acrylic substrate with an electron beam according to the design structure comprises: dividing the design structure into a plurality of processing points; obtaining the processing sequence and processing depth of each processing point according to the design structure; obtaining the irradiation point on the acrylic substrate according to the processing point; obtaining the irradiation sequence on the acrylic substrate according to the processing sequence; irradiating the irradiation point on the acrylic substrate with the electron beam according to the processing depth according to the irradiation sequence.

3. The method of claim 2, wherein, Obtaining the processing depth of each processing point according to the design structure comprises: obtaining the depth information contained in each processing point of the design structure; obtaining the processing depth of each processing point according to the depth information.

4. The method of claim 2, wherein, Obtaining the processing depth of each processing point according to the design structure comprises: obtaining the color information contained in each processing point of the design structure; obtaining the processing depth corresponding to the color information contained in each processing point.

5. The method of claim 2, wherein, The irradiation with the electron beam according to the processing depth comprises: obtaining the irradiation dose corresponding to the processing depth; irradiating with an electron beam according to the irradiation dose.

6. The method of claim 5, wherein, The irradiation dose corresponding to the processing depth comprises: obtaining the irradiation intensity within a preset time period; and / or obtaining the irradiation time under a preset irradiation intensity.

7. An electron beam lithography micro-nano structure processing device, characterized in that, The device comprises: a substrate preparation unit for preparing an acrylic substrate; a structure design unit for obtaining a design structure; a processing unit for irradiating the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure; The substrate preparation unit is further configured to: plate a metal layer on the irradiation surface of an acrylic substrate to prepare the acrylic substrate, wherein the acrylic substrate comprises an irradiation surface and a bottom surface, and the irradiation surface and the bottom surface of the acrylic substrate are oppositely arranged.

8. An anti-counterfeiting marking, characterized in that The method according to any one of claims 1 to 6.

9. A reflection grating, characterized by, The method according to any one of claims 1 to 6.

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