Electron beam lithography micro-nano structure processing method and equipment, anti-counterfeiting mark and reflection grating

Abstract

The invention relates to an electron beam lithography micro-nano structure processing method and equipment, an anti-counterfeiting 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 adopting an electron beam according to the design structure so as to obtain the micro-nano structure with the design structure. According to the invention, the micro-nano structure processing is carried out on the acrylic material, the processing process of the electron beam lithography micro-nano structure is simplified, and the material cost and the labor cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano processing, and in particular to an electron beam lithography micro-nano structure processing method, equipment, anti-counterfeiting mark and reflection grating. Background Art

[0002] Micro-nano processing is an advanced processing technology. This technology is a technology that transfers the micro-nano structure on the template to the material to be processed through a light beam. It is an important processing method in the field of microelectronics and materials.

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

[0004] It can be seen that the electron beam lithography micro-nano processing method in the prior art is costly and the process stability depends on the consistency of the raw materials. Summary of the invention

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

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

[0007] preparing an acrylic substrate;

[0008] Get the design structure;

[0009] According to the design structure, the acrylic substrate is irradiated with an electron beam to obtain a micro-nano structure with the design structure.

[0010] Optionally, the step of preparing the acrylic substrate comprises:

[0011] A metal layer is plated on the irradiated surface of the acrylic substrate to prepare the acrylic base, wherein the acrylic substrate comprises an irradiated surface and a bottom surface, and the irradiated surface and the bottom surface of the acrylic substrate are arranged opposite to each other.

[0012] Optionally, according to the design structure, the acrylic substrate is irradiated with an electron beam, including:

[0013] Dividing the design structure into a dot matrix including a plurality of processing points;

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

[0015] According to the processing point, obtaining an irradiation point on the acrylic substrate;

[0016] According to the processing sequence, obtaining an irradiation sequence on the acrylic substrate;

[0017] According to the irradiation sequence, the electron beam is used for irradiation at the irradiation point of the acrylic substrate according to the processing depth.

[0018] Optionally, obtaining a processing depth of each processing point according to the design structure includes:

[0019] Acquire depth information contained in each processing point of the design structure;

[0020] The processing depth of each processing point is obtained according to the depth information.

[0021] Optionally, obtaining a processing depth of each processing point according to the design structure includes:

[0022] Acquire color information contained in each processing point of the design structure;

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

[0024] Optionally, the irradiating with the electron beam according to the processing depth includes:

[0025] Obtaining an irradiation dose corresponding to the processing depth;

[0026] According to the irradiation dose, irradiation is performed using an electron beam.

[0027] Optionally, obtaining the irradiation dose corresponding to the processing depth includes:

[0028] Obtaining the radiation intensity within a preset time period; and / or

[0029] Get the irradiation time under the preset irradiation intensity.

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

[0031] A substrate preparation unit, used for preparing an acrylic substrate;

[0032] A structural design unit, used to obtain a design structure;

[0033] The processing unit is used to irradiate the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure.

[0034] In a third aspect, an anti-counterfeiting mark is provided, using any of the methods described above.

[0035] In a fourth aspect, a reflection grating is provided, applying the method described in any of the above items.

[0036] The present invention relates to an electron beam lithography micro-nano structure processing method, equipment, anti-counterfeiting mark and reflective grating, the method comprising: preparing an acrylic substrate; obtaining a design structure; according to the design structure, irradiating the acrylic substrate with an electron beam to obtain a micro-nano structure with the design structure. In the method of the embodiment of the present invention, the acrylic substrate is irradiated with an electron beam to obtain a micro-nano structure with the design structure, and there is no need to coat a resist on the base, and there is no need to coat glue, develop and other steps, which simplifies the process of traditional electron beam lithography micro-nano structure processing. In addition, since there is no need for additional coating of glue and development, and there is no need to coat a resist, the material cost and labor cost can be reduced. At the same time, since the electron beam lithography of acrylic material is the height change of the acrylic material surface caused by the change in the density of the acrylic material, the micro-nano structure processed by the method of the embodiment of the present invention has good continuity and high resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0039] Figure 1 A flowchart of the electron beam lithography micro-nano structure processing method according to an embodiment of the present invention;

[0040] Figure 2 It is a schematic diagram of electron beam lithography micro-nano structure processing of a reflective structure according to an embodiment of the present invention;

[0041] Figure 3 Shown is a schematic diagram of the design structure of an embodiment of the present invention;

[0042] Figure 4 It is a structural block diagram of an electron beam lithography micro-nano structure processing device according to an embodiment of the present invention;

[0043] Figure 5 Shown is a schematic diagram of an anti-counterfeiting mark according to an embodiment of the present invention;

[0044] Figure 6 FIG. 4 is a schematic diagram of an electron beam lithography micro-nano structure processing system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The embodiment of the present invention provides a method for processing micro-nano structures by electron beam lithography, such as Figure 1 As shown, the method includes:

[0047] Step 110, preparing an acrylic substrate;

[0048] Step 120, obtaining a design structure;

[0049] Step 130: According to the design structure, the acrylic substrate is irradiated with an electron beam to obtain a micro-nano structure with the design structure.

[0050] The basic principle of electron beam lithography is to break or bond the molecular chains of the resist through electron beam irradiation, thereby changing the solubility of the resist in the developer and achieving the effect of distinguishing the exposed area from the non-exposed area. PMMA (polymethyl methacrylate), as the most common positive resist in electron beam lithography, will be converted from long-chain molecules to short-chain molecules after electron beam irradiation, thereby increasing its solubility in the developer. After experiments, it was found that after PMMA was converted from long-chain molecules to short-chain molecules, its density would change, resulting in the difference between the exposed area and the non-exposed area before development. The height of the area irradiated by the electron beam will be significantly smaller than that of the unexposed area. In addition, the shrinkage depth of PMMA is linearly related to the dose within a certain range. As the exposure dose increases, the processing depth also increases. The processing depth can be accurately controlled by controlling the exposure dose.

[0051] Acrylic material is essentially PMMA, so after being irradiated by electron beam, acrylic material can also be changed from long-chain molecules to short-chain molecules, and can be used as a material for electron beam lithography micro-nanostructure processing. In fact, the method of the present invention can be applied to other PMMAs, and can also be applied to other materials that will produce obvious deformation due to electron beam irradiation.

[0052] In the method of the embodiment of the present invention, the acrylic substrate is irradiated with an electron beam to obtain a micro-nano structure with the designed structure, and no resist is required to be coated on the substrate, and no steps such as glue coating and development are required, thereby simplifying the process of traditional electron beam lithography micro-nano structure processing. In addition, since no additional glue coating and development are required, and no resist coating is required, material costs and labor costs can be reduced.

[0053] At the same time, since the electron beam lithography of acrylic material causes the height change of the acrylic material surface due to the change of the density of the acrylic material, the micro-nano structure processed by the method of the embodiment of the present invention has good continuity and high resolution. After experimental verification, the method of the embodiment of the present invention can achieve a resolution of less than 10nm in the processing plane and a resolution of more than 1nm in the processing depth.

[0054] The method of the embodiment of the present invention can be used to process micro-nano structures of transmission structures, for example Figure 1 The method of the embodiment of the present invention can also be used to process micro-nano structures of reflective structures, in which case a metal layer needs to be plated.

[0055] In the embodiment of the present invention, the design structure may be various patterns, texts, or anti-counterfeiting marks, etc., which will not be described in detail here.

[0056] In the embodiment of the present invention, the preparation of the acrylic substrate may include cutting and slicing of the acrylic substrate, and may also include surface polishing, etc. Both the irradiated surface and the bottom surface of the acrylic substrate need to have a certain degree of flatness. Usually, the surface of the acrylic substrate is relatively flat and can meet the processing requirements. In this case, the irradiated surface and the bottom surface do not need to be polished.

[0057] In an embodiment of the present invention, the preparation of the acrylic substrate comprises:

[0058] A metal layer is plated on the irradiated surface of the acrylic substrate to prepare the acrylic base, wherein the acrylic substrate comprises an irradiated surface and a bottom surface, and the irradiated surface and the bottom surface of the acrylic substrate are arranged opposite to each other.

[0059] Figure 2 FIG. 1 is a schematic diagram of electron beam lithography micro-nano structure processing of a reflective structure according to an embodiment of the present invention. Figure 2 (a) shows an acrylic substrate. Figure 2 (b) shows the metal layer plated on the irradiated surface. Figure 2 (c) shows the processed micro-nano structure.

[0060] In the embodiment of the present invention, in step 130, the step of irradiating the acrylic substrate with an electron beam according to the design structure includes:

[0061] Dividing the design structure into a plurality of processing points;

[0062] According to the design structure, obtaining the processing sequence and processing depth of each processing point;

[0063] According to the processing point, obtaining an irradiation point on the acrylic substrate;

[0064] According to the processing sequence, obtaining an irradiation sequence on the acrylic substrate;

[0065] According to the irradiation sequence, the electron beam is used for irradiation at the irradiation point of the acrylic substrate according to the processing depth.

[0066] Figure 3 FIG. 1 is a schematic diagram of a design structure of an embodiment of the present invention. Figure 3 (a) is the design structure, Figure 3 (b) The point matrix of the designed structure.

[0067] The processing order can be in row order, column order, or alphabetical / text order, e.g. Figure 3 In the process, E is processed first, then B, and finally L.

[0068] In an embodiment of the present invention, obtaining the processing depth of each processing point according to the design structure includes:

[0069] Acquire depth information contained in each processing point of the design structure;

[0070] The processing depth of each processing point is obtained according to the depth information.

[0071] In an embodiment of the present invention, obtaining the processing depth of each processing point according to the design structure includes:

[0072] Acquire color information contained in each processing point of the design structure;

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

[0074] Acrylic material / acrylic base itself has very good light transmittance and is transparent. Even after being exposed to an electronic book, it cannot directly carry color. After being exposed to an electron beam, the surface of the acrylic base is different in height, and the refractive index of light of different wavelengths is also different. Therefore, the acrylic base after electron beam lithography can interfere in the area of ​​height change when light passes through, thereby presenting different colors to the outside.

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

[0076] In the embodiment of the present invention, the processing depth may be determined based on the depth information of the design structure itself, or may be determined based on the color information, or may be determined based on both the color and the depth information.

[0077] In an embodiment of the present invention, the irradiation using the electron beam according to the processing depth includes:

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

[0079] According to the irradiation dose, irradiation is performed using an electron beam.

[0080] In an embodiment of the present invention, obtaining the irradiation dose corresponding to the processing depth includes:

[0081] Obtaining the radiation intensity within a preset time period; and / or

[0082] Get the irradiation time under the preset irradiation intensity.

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

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

[0085] like Figure 4 As shown, an embodiment of the present invention further provides an electron beam lithography device for micro-nanostructure processing, the device comprising:

[0086] A substrate preparation unit 410 is used to prepare an acrylic substrate;

[0087] A structure design unit 420, used to obtain a design structure;

[0088] The processing unit 430 is used to irradiate the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure.

[0089] In the embodiment of the present invention, the substrate preparation unit 410 is further used for:

[0090] A metal layer is plated on the irradiated surface of the acrylic substrate to prepare the acrylic base, wherein the acrylic substrate comprises an irradiated surface and a bottom surface, and the irradiated surface and the bottom surface of the acrylic substrate are arranged opposite to each other.

[0091] In the embodiment of the present invention, the processing unit 430 is further used for:

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

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

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

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

[0096] According to the irradiation sequence, the electron beam is used for irradiation at the irradiation point of the acrylic substrate according to the processing depth.

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

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

[0099] The processing depth of each processing point is obtained according to the depth information.

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

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

[0102] The processing depth corresponding to the color information contained in each processing point is obtained.

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

[0104] Obtaining an irradiation dose corresponding to the processing depth;

[0105] According to the irradiation dose, irradiation is performed using an electron beam.

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

[0107] Obtaining the radiation intensity within a preset time period; and / or

[0108] Get the irradiation time under the preset irradiation intensity.

[0109] The device of the embodiment of the present invention performs electron beam lithography micro-nano structure processing on acrylic materials, simplifies the process of traditional electron beam lithography micro-nano structure processing, can reduce material costs and labor costs, and also has good continuity and high resolution.

[0110] The embodiment of the present invention further provides an anti-counterfeiting mark, which uses the above method.

[0111] Figure 5FIG. 1 is a schematic diagram of an anti-counterfeiting mark according to an embodiment of the present invention. Figure 5 As shown, after the electron beam lithography micro-nano structure is processed by the above method of the present invention, a white screen 520 can be set behind the anti-counterfeiting mark 510 for easy observation, and the anti-counterfeiting mark can be illuminated by a white light source 530, and the pattern of the anti-counterfeiting mark can be displayed on the white screen 520. The anti-counterfeiting mark can be various patterns with depth information and color information.

[0112] In the embodiments of the present invention, since the molecular weights of the acrylic substrates vary greatly from batch to batch, the processing depths, colors, etc. are all different due to the different molecular weights. Therefore, the product batches can be reasonably controlled to achieve the purpose of being almost impossible to imitate, thereby enabling the anti-counterfeiting structure with excellent anti-counterfeiting performance to be processed at low cost.

[0113] The embodiment of the present invention further provides a reflection grating, to which the above-mentioned method is applied.

[0114] The reflection grating of the embodiment of the present invention needs to be plated with a metal film on the irradiated surface before processing.

[0115] The thickness of the metal film is usually in the order of 200nm-1μm. After coating, the acrylic substrate is opaque and has a mirror surface on the coated surface.

[0116] In the embodiment of the present invention, the structure of the reflective grating can refer to Figure 2 There are undulating sawtooth structures in the grating, but the grating is not limited to sawtooth. The height of a single sawtooth is usually in the order of hundreds of nanometers, and the width is in the order of micrometers to hundreds of nanometers.

[0117] In the embodiment of the present invention, after the electron beam lithography on the acrylic substrate is completed, the reflective grating has been formed, and there is no need to go through the steps of developing and coating like the conventional electron beam lithography method. This can save labor costs and material costs, and can also simplify the processing procedures.

[0118] The embodiment of the present invention also provides an electron beam lithography micro-nano structure processing 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, etc., and can perform electron beam lithography micro-nano structure processing on an acrylic substrate 650.

[0119] Figure 1 FIG. 1 is a schematic diagram of a process for processing a micro-nano structure in one embodiment. It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0120] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, 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 embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention 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 and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0121] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0122] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An electron beam lithography micro-nano structure processing method, characterized in that: The method comprises: preparing an acrylic substrate; Get the design structure; According to the design structure, the acrylic substrate is irradiated with an electron beam to obtain a micro-nano structure with the design structure.

2. The method according to claim 1, characterized in that The method for preparing the acrylic substrate comprises: A metal layer is plated on the irradiated surface of the acrylic substrate to prepare the acrylic base, wherein the acrylic substrate comprises an irradiated surface and a bottom surface, and the irradiated surface and the bottom surface of the acrylic substrate are arranged opposite to each other.

3. The method according to claim 1, characterized in that According to the design structure, the acrylic substrate is irradiated with an electron beam, including: Dividing the design structure into a plurality of processing points; According to the design structure, obtaining the processing sequence and processing depth of each processing point; According to the processing point, obtaining an irradiation point on the acrylic substrate; According to the processing sequence, obtaining an irradiation sequence on the acrylic substrate; According to the irradiation sequence, the electron beam is used for irradiation at the irradiation point of the acrylic substrate according to the processing depth.

4. The method according to claim 3, characterized in that: According to the design structure, obtaining the processing depth of each processing point includes: Acquire depth information contained in each processing point of the design structure; The processing depth of each processing point is obtained according to the depth information.

5. The method according to claim 3, characterized in that: According to the design structure, obtaining the processing depth of each processing point includes: Acquire color information contained in each processing point of the design structure; The processing depth corresponding to the color information contained in each processing point is obtained.

6. The method according to claim 3, characterized in that The step of irradiating with the electron beam according to the processing depth comprises: Obtaining an irradiation dose corresponding to the processing depth; According to the irradiation dose, irradiation is performed using an electron beam.

7. The method according to claim 6, characterized in that The obtaining of the irradiation dose corresponding to the processing depth includes: Obtaining the radiation intensity within a preset time period; and / or Get the irradiation time under the preset irradiation intensity.

8. An electron beam lithography micro-nano structure processing device, characterized in that: The device comprises: A substrate preparation unit, used for preparing an acrylic substrate; A structural design unit, used to obtain a design structure; The processing unit is used to irradiate the acrylic substrate with an electron beam according to the design structure to obtain a micro-nano structure with the design structure.

9. An anti-counterfeiting mark, characterized in that: The method according to any one of claims 1 to 7 is applied.

10. A reflection grating, characterized in that: The method according to any one of claims 1 to 7 is applied.

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