A method for processing a diffractive optical element by template controlling the thickness of a residue layer

Abstract

This invention relates to a method for fabricating diffractive optical elements by controlling the thickness of the residual adhesive layer using a template. The method includes the following steps: establishing a structural compensation relationship between the template and the diffractive optical element; determining the etching rate of the residual adhesive layer and the pattern size on the template surface based on the diffraction grating dimensions of different zones of the diffractive optical element, and forming the template; using the template to imprint the pattern onto an imprintable medium, pressing an inorganic dielectric substrate onto the surface of the imprintable medium, allowing the imprintable medium to solidify, demolding, and detecting the thickness of the residual adhesive layer on the minimum duty cycle zone; and simultaneously etching the imprintable medium in different zones according to the etching time and etching rate to simultaneously complete the etching of the residual adhesive layer. This invention compensates for the residual adhesive layer structure by controlling the template, solving the problem of inconsistent residual adhesive layer processing in existing imprint-to-etch methods. It can simultaneously etch the residual adhesive layer in different zones without changing the linewidth of the structural region, resulting in high processing reliability and suitability for industrial applications.

Description

Technical Field

[0001] This invention relates to the field of nanoimprint technology, and in particular to a method for fabricating diffractive optical elements by controlling the thickness of the residual adhesive layer through a template. Background Technology

[0002] Diffractive optical elements (DOEs) can precisely control light intensity distribution while maintaining high diffraction efficiency. Due to their more diverse light field manipulation capabilities, they offer high flexibility and customizability, enabling smaller and lighter designs and superior optical performance. Therefore, they have unique advantages in fields such as AR, HUD, 3D sensing, and planar imaging. (Refer to...) Figure 1 Existing diffractive optical elements are generally processed using nanoimprint technology. Since the structural layer of DOE is an imprint adhesive (organic polymer), compared with inorganic materials such as quartz, glass, and silicon, it has defects such as poor hardness, easy scratching, easy structural damage during cleaning, and yellowing and cracking due to high temperature or long-term light accumulation. Its weather resistance and hardness cannot meet the requirements of future products. Therefore, for the sake of cost and consistency, imprinting to etching has become the processing method most likely to achieve mass production.

[0003] Reference Figure 2 In existing imprint etch-to-etch (IMT) processes, different diffraction grating structures, due to variations in duty cycles, make it difficult to remove the groove structure layer while maintaining the same structure as the initial one. Therefore, over-etching is necessary to ensure the groove residual adhesive is completely removed. Only after the groove residual adhesive is completely etched can the next etching step be performed to transfer the imprint adhesive pattern onto the glass / quartz substrate. During over-etching, areas where residual adhesive is prematurely etched may exhibit changes in duty cycle and height, affecting the target structure. Alternatively, some areas may have their imprint adhesive structure completely consumed, preventing further pattern transfer. These issues require improvement. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer through a template, which addresses the above-mentioned shortcomings of the prior art. By controlling the template to compensate for the structure of the residual adhesive layer, the present invention solves the problem of inconsistent processing of the residual adhesive layer in the existing imprinting and etching method. It achieves the effect of simultaneously etching the residual adhesive layer in different partitions without changing the linewidth of the structural region, resulting in high processing reliability and suitability for industrial applications.

[0005] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0006] A method for fabricating diffractive optical elements by controlling the thickness of the residual adhesive layer using a template includes the following steps:

[0007] S1 establishes the structural compensation relationship between the template and the diffraction optical element, determines the etching rate of the residual adhesive layer and the pattern size on the template surface based on the diffraction grating size of different partitions of the diffraction optical element, and forms the template.

[0008] ;

[0009] w1: w n =v1:v n ;

[0010] Where t is the etching time of the residual adhesive layer, d is the thickness of the residual adhesive layer on the minimum duty cycle partition, and w1, h1, and v1 are the diffraction grating linewidth, template pattern depth, and residual adhesive layer etching rate on the minimum duty cycle partition, respectively. n h n v n For the diffraction grating linewidth, template pattern depth, and residual adhesive layer etching rate on other partitions, n≥2;

[0011] S2 uses the template obtained in S1 to imprint the pattern onto the imprintable medium, and after pressing the inorganic medium substrate onto the surface of the imprintable medium, the imprintable medium is imprinted and cured, demolded, and the thickness d of the residual adhesive layer on the minimum duty cycle partition is detected.

[0012] Based on the etching time and etching rate obtained in S1, S3 synchronously etches the imprintable medium obtained in S2 in separate sections to simultaneously complete the etching of the residual adhesive layer.

[0013] Specifically, in a typical thermoimprinting process, the imprintable medium is not limited to, for example, a resin. The imprintable medium is not limited to, for example, spin-coated and baked onto the surface of an inorganic substrate. When using a thermosetting polymer resin, the resin is heated to a temperature such that, upon contact with a template, the resin is sufficiently flowable to flow into a pattern defined on the template. The resin temperature is then increased to thermally cure (crosslink) the resin, causing it to cure irreversibly and form the desired pattern. The template is then removed, and the patterned resin is cooled. In thermoimprinting lithography using a thermoplastic polymer resin layer, the thermoplastic resin is heated so that, just before imprinting with the template... Thermoplastic resin is in a free-flowing state. It may be necessary to heat the thermoplastic resin to a temperature much higher than the glass transition temperature of the resin. A template is pressed into the free-flowing resin and then cooled to below its glass transition temperature while the template is in situ to solidify the pattern. Subsequently, the template is removed, and the pattern will consist of raised features in the remaining layer of the imprintable medium. This can then be removed by a suitable etching process, leaving only the pattern features. Examples of thermoplastic polymer resins used in thermoimprint lithography processes are poly(methyl isobutylene), polystyrene, poly(phenylmethyl isobutylene), or poly(cyclohexyl methacrylate).

[0014] Alternatively, in a typical UV-curable embossing process, which involves using a transparent or translucent template that transmits UV radiation and a UV-curable liquid as the imprintable medium (the term "UV" is used here for convenience, but it should be understood to include any suitable photochemical radiation used to cure the imprintable medium), the viscosity of the UV-curable liquid is generally not as high as that of thermosetting and thermoplastic resins used in thermal embossing, and as a result, it can move more quickly to fill the template pattern features. The template can be applied to a UV-curable resin or photoresist. However, instead of using heat or temperature cycling as in thermal embossing, the pattern is cured by UV radiation applied to the imprintable medium through the template, and the imprintable medium is etched after the template is removed.

[0015] In addition, a combination of the above-mentioned hot embossing and UV curing embossing technologies is also possible.

[0016] Furthermore, in S1, the etching rate v1 of the residual adhesive layer on the minimum duty cycle partition is controlled to be 1.0~7.0 nm / s.

[0017] Furthermore, in S1, the inorganic dielectric of the inorganic dielectric substrate and the template material of the template are each independently selected from quartz, silicon, glass, YAG, CaF2, or sapphire.

[0018] Furthermore, in S2, the thickness d of the residual adhesive layer on the minimum duty cycle partition is controlled to be 10~100nm, and the imprintable medium is Delo OM6113 photoresist or Delo OM614 photoresist.

[0019] Furthermore, S2 includes the following steps:

[0020] S21 Place the template and an evaporating dish containing 0.5~1.5mL of release agent into a vacuum drying oven, and evacuate to 10°C. -4 After Pa, stop pumping and maintain for 25-35 minutes. The release agent will then evaporate and cover the mold surface.

[0021] S22 First, place the template obtained in S21 on a spin coater and fix it under vacuum adsorption. Then, drop 1~6mL of imprintable medium onto the pattern of the template. Then, spin coat at a low speed of 400~600rpm for 4~6s, followed by spin coat at a high speed of 2000~6000rpm for 50~70s. After spin coat is completed, bake at 100~180℃ for 1~3min.

[0022] S23 First, place the inorganic dielectric substrate on a spin coater and fix it under vacuum adsorption. Then, drop 1-2 mL of tackifier onto the surface of the inorganic dielectric substrate. Then, spin coat at a low speed of 400-600 rpm for 4-6 seconds, followed by spin coat at a high speed of 2000-6000 rpm for 50-70 seconds. After spin coat is completed, bake at 100-180℃ for 1-3 minutes.

[0023] S24 First, the template obtained in S22 is mounted on the imprinting machine. Then, the inorganic dielectric substrate obtained in S23 is mounted on the imprintable medium. The imprinting machine then applies a pressure of 100~1000N and performs 365nm UV curing under nitrogen protection with a curing energy of 300~600mJ / cm². 2 After UV curing, the mold is removed along the gap between the template and the inorganic substrate to transfer the imprintable medium onto the inorganic substrate.

[0024] S25 uses an ellipsometry to detect the thickness of the residual adhesive layer d on the minimum duty cycle zone by measuring the thickness of the residual adhesive layer at the bottom of the thinnest groove in the unstructured area of ​​the imprintable medium or on the longitudinal section.

[0025] Furthermore, in S2, the release agent is 1H,1H,2H,2H-perfluorooctyltrichlorosilane, and the tackifier is AP3000 tackifier.

[0026] Furthermore, in S3, the etching conditions are controlled as follows: CHF3 10~40 sccm, SF6 0~20 sccm, O2 0~100 sccm, ICP Power 100~300W, and Bias Power 0~100W.

[0027] Furthermore, in S3, the process further includes etching the inorganic dielectric substrate after etching the residual adhesive layer to form a diffraction grating on the surface of the inorganic dielectric substrate.

[0028] Furthermore, S3 includes the following steps:

[0029] S31 uses an ICP etching device to simultaneously etch the imprintable medium and inorganic medium substrate obtained in S2 in sections. Oxygen is used to etch the imprintable medium downward to a certain depth, so that the bottom of the groove is exposed to the inorganic medium substrate, which is convenient for the next step of pattern transfer etching. The etching conditions are ICP Power 200W, Bias 0, O2 60sccm.

[0030] S32 continues to etch the surface of the inorganic dielectric substrate to form a diffraction grating on the surface of the inorganic dielectric substrate. The etching rate of the inorganic dielectric is 5.4 nm / s, and the etching conditions are CHF3 40 sccm, SF6 10 sccm, O2 0 sccm, ICP Power 300W, and Bias Power 150W.

[0031] The S33 uses a plasma etching machine to remove any remaining resist. The etching conditions are: O2 80 sccm, Power 300W, 10 min.

[0032] In summary, the beneficial technical effects of the present invention are as follows:

[0033] 1. The inconsistent thickness of residual adhesive caused by the amount of adhesive absorbed makes the subsequent adhesive removal and etching process extremely complicated. Therefore, this invention addresses the shortcomings of current nanoimprint diffraction optical elements and imprint-to-etching by compensating for the template structure. This solves the problem of inconsistent residual adhesive layer in previous imprint-to-etching processes, thereby achieving precise processing of diffraction optical elements and controlling the thickness of the residual adhesive layer in all areas to be consistent.

[0034] 2. This invention, based on the different duty cycles of different structural regions of the target diffractive optical element and the different groove volume ratios of different structural regions, maintains a consistent amount of adhesive absorption in all raised areas of the template. That is, areas with a large duty cycle have a lower grating height, and areas with a small duty cycle have a higher grating height. Furthermore, by compensating for the grating height of the corresponding areas of the template through the etching rate of the residual adhesive layer, it can be ensured that each partition can be etched completely during the etching process of removing the residual adhesive layer without changing the linewidth of the structural region. This ensures that the target structure of the target diffractive optical element is transferred onto a glass or quartz substrate, and can serve as an effective solution for the industrialization of highly reliable diffractive optical elements with a reliable process route. Attached Figure Description

[0035] Figure 1 This is a flowchart of a conventional nanoimprinting method in the background of this invention.

[0036] Figure 2 This is a flowchart of an existing imprint-to-etch process in the background art of this invention.

[0037] Figure 3 This is a flowchart of the processing method of Embodiment 1 of the present invention.

[0038] Figure 4 This is a schematic diagram of the structure of the diffractive optical element imprint template in Embodiment 2 of the present invention.

[0039] Figure 5 This is an electron microscope image of a diffractive optical element prepared by the processing method of Embodiment 6 of the present invention. Detailed Implementation

[0040] To make the technical means, creative features, objectives and effects of this invention clearer and easier to understand, the invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0041] Example 1: Refer to Figure 3 This invention discloses a method for fabricating diffractive optical elements by controlling the thickness of the residual adhesive layer using a template, comprising the following steps:

[0042] S1 establishes the structural compensation relationship between the template and the diffraction optical element. Based on the diffraction grating size of different partitions of the diffraction optical element, the etching rate of the residual adhesive layer and the pattern size on the template surface are determined, and the template is formed.

[0043] ;

[0044] w1: w n =v1:v n ;

[0045] Where t is the etching time of the residual adhesive layer, d is the thickness of the residual adhesive layer on the minimum duty cycle partition, and w1, h1, and v1 are the diffraction grating linewidth, template pattern depth, and residual adhesive layer etching rate on the minimum duty cycle partition, respectively. n h n v n For the diffraction grating linewidth, template pattern depth, and residual adhesive layer etching rate on other partitions, n≥2;

[0046] S2 uses the template obtained in S1 to imprint the pattern onto the imprintable medium, and after pressing the inorganic medium substrate onto the surface of the imprintable medium, the imprintable medium is imprinted and cured, demolded, and the thickness d of the residual adhesive layer on the minimum duty cycle partition is detected.

[0047] Based on the etching time and etching rate obtained from S1, S3 synchronously etches the imprintable medium obtained from S2 in separate sections to simultaneously complete the etching of the residual adhesive layer.

[0048] Example 2: Refer to Figure 4 This invention discloses a method for fabricating diffractive optical elements by controlling the thickness of the residual adhesive layer using a template. The difference from Example 1 is that it requires the fabrication of quartz substrate diffractive optical elements with three different duty cycles, a period of 400 nm, a depth of 200 nm, and a linewidth of w. 1~3 The corresponding wavelengths are 200nm, 150nm, and 70nm. By calculating the groove volume, a correspondingly compensated silicon substrate template is first designed and fabricated. The imprinting-etching process is then performed by controlling the thickness of the residual adhesive mask layer to be consistent through compensation.

[0049] Specifically, S1 includes the following steps:

[0050] S11 is based on the linewidth w of the diffraction grating of the diffraction optical element. 1~3 and height h 1~3 These diffraction gratings are divided into three regions (A~C regions), and the linewidth of the imprintable protrusions of the imprintable medium is determined by combining the period of the diffraction optical elements, thereby determining the linewidth of the pattern on the surface of the imprint template to be 200nm, 250nm, and 330nm.

[0051] S12 controls the residual adhesive layer etching rate v on the minimum duty cycle partition. 1~3 With speeds of 2.5 nm / s, 5.5 nm / s, and 7.4 nm / s, the residual adhesive layer thickness d on the minimum duty cycle partition is 50 nm, thus yielding the template pattern depth h. 1~3 For 150nm, 200nm, and 428nm;

[0052] S13 is patterned using electron beam lithography, ultraviolet lithography, or laser direct writing equipment, and then the pattern is transferred to the silicon substrate using ion beam etching. Finally, the electron beam lithography resist or ultraviolet lithography resist is removed to obtain the imprint template.

[0053] Example 3: This invention discloses a method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template. The difference from Example 2 is that step S2 includes the following steps:

[0054] S21 Place the imprint template and an evaporating dish containing 1.0 mL of 1H,1H,2H,2H-perfluorooctyltrichlorosilane into a vacuum drying oven and evacuate to 10 °C. -4 After Pa, stop pumping and maintain for 30 minutes. The release agent will evaporate and cover the surface of the impression template.

[0055] S22 First, place the imprinting template obtained in S21 on a spin coater and fix it under vacuum adsorption. Then, drop 4 mL of imprintable medium onto the pattern of the imprinting template. Then, spin coat at a low speed of 500 rpm for 5 seconds, followed by spin coat at a high speed of 4000 rpm for 60 seconds. After spin coat is completed, bake at 120℃ for 2 minutes.

[0056] S23 First, place the inorganic dielectric substrate on a spin coater and fix it under vacuum adsorption. Then, drop 1 mL of AP3000 tackifier onto the surface of the inorganic dielectric substrate. Then, spin coat at a low speed of 500 rpm for 5 seconds, followed by spin coat at a high speed of 4000 rpm for 60 seconds. After spin coat is completed, bake at 120℃ for 2 minutes.

[0057] S24 First, the imprinting template obtained in S22 is mounted on the imprinting machine. Then, the inorganic dielectric substrate obtained in S23 is mounted on the imprintable medium. The imprinting machine then applies a pressure of 100~1000N and performs 365nm UV curing under nitrogen protection with a curing energy of 400mJ / cm². 2 After UV curing, the mold is removed along the gap between the imprinting template and the inorganic dielectric substrate to transfer the imprintable medium onto the inorganic dielectric substrate.

[0058] S25 uses an ellipsometry to detect the thickness of the residual adhesive layer d on the minimum duty cycle zone by measuring the thickness of the unstructured area or the bottom residual adhesive layer on the longitudinal section of the imprintable medium.

[0059] Example 4: This invention discloses a method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template. The difference from Example 3 is that step S2 includes the following steps:

[0060] S21 places the imprint template and an evaporating dish containing 0.5 mL of 1H,1H,2H,2H-perfluorooctyltrichlorosilane into a vacuum drying oven and evacuates to 10 °C. -4 After Pa, stop pumping and maintain for 25 minutes. Then, the release agent will evaporate and cover the surface of the impression template.

[0061] S22 First, place the imprinting template obtained in S21 on a spin coater and fix it under vacuum adsorption. Then, drop 1 mL of imprintable medium onto the pattern of the imprinting template. Then, spin coat at a low speed of 400 rpm for 4 seconds, followed by spin coat at a high speed of 2000 rpm for 50 seconds. After spin coat is completed, bake at 100℃ for 1 minute.

[0062] S23 First, place the inorganic dielectric substrate on a spin coater and fix it under vacuum adsorption. Then, drop 1 mL of AP3000 tackifier onto the surface of the inorganic dielectric substrate. Then, spin coat at a low speed of 400 rpm for 4 seconds, followed by spin coat at a high speed of 2000 rpm for 50 seconds. After spin coat is completed, bake at 100℃ for 1 minute.

[0063] S24 First, the imprinting template obtained in S22 is mounted on the imprinting machine. Then, the inorganic dielectric substrate obtained in S23 is mounted on the imprintable medium. The imprinting machine then applies a pressure of 100~1000N and performs 365nm UV curing under nitrogen protection with a curing energy of 300mJ / cm². 2 After UV curing, the mold is removed along the gap between the imprinting template and the inorganic dielectric substrate to transfer the imprintable medium onto the inorganic dielectric substrate.

[0064] S25 uses an ellipsometry to detect the thickness of the residual adhesive layer d on the minimum duty cycle zone by measuring the thickness of the unstructured area or the bottom residual adhesive layer on the longitudinal section of the imprintable medium.

[0065] Example 5: This invention discloses a method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template. The difference from Example 3 is that step S2 includes the following steps:

[0066] S21 places the imprint template and an evaporating dish containing 1.5 mL of 1H,1H,2H,2H-perfluorooctyltrichlorosilane into a vacuum drying oven and evacuates to 10 °C. -4 After Pa, stop pumping and maintain for 35 minutes. Then, the release agent will evaporate and cover the surface of the impression template.

[0067] S22 First, place the imprinting template obtained in S21 on a spin coater and fix it under vacuum adsorption. Then, drop 6 mL of imprintable medium onto the pattern of the imprinting template. Then, spin coat at a low speed of 600 rpm for 6 seconds, followed by spin coat at a high speed of 6000 rpm for 70 seconds. After spin coat is completed, bake at 180℃ for 3 minutes.

[0068] S23 First, place the inorganic dielectric substrate on a spin coater and fix it under vacuum adsorption. Then, drop 2 mL of AP3000 tackifier onto the surface of the inorganic dielectric substrate. Then, spin coat at a low speed of 600 rpm for 6 seconds, followed by spin coat at a high speed of 6000 rpm for 70 seconds. After spin coat is completed, bake at 180℃ for 3 minutes.

[0069] S24 First, the imprinting template obtained in S22 is mounted on the imprinting machine. Then, the inorganic dielectric substrate obtained in S23 is mounted on the imprintable medium. Next, the imprinting machine applies a pressure of 1000N and performs 365nm UV curing under nitrogen protection with a curing energy of 600mJ / cm². 2 After UV curing, the mold is removed along the gap between the imprinting template and the inorganic dielectric substrate to transfer the imprintable medium onto the inorganic dielectric substrate.

[0070] S25 uses an ellipsometry to detect the thickness of the residual adhesive layer d on the minimum duty cycle zone by measuring the thickness of the unstructured area or the bottom residual adhesive layer on the longitudinal section of the imprintable medium.

[0071] Example 6: This invention discloses a method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template. The difference from Example 3 is that step S3 includes the following steps:

[0072] S31 uses an ICP etching device to simultaneously etch the imprintable medium and inorganic medium substrate obtained in S2 in sections. Oxygen is used to etch the imprintable medium downward to a certain depth, so that the bottom of the groove is exposed to the inorganic medium substrate, which is convenient for the next step of pattern transfer etching. The etching conditions are ICP Power 200W, Bias 0, O2 60sccm.

[0073] S32 continues to etch the surface of the inorganic dielectric substrate to form a diffraction grating on the surface of the inorganic dielectric substrate. The etching rate of the inorganic dielectric is 5.4 nm / s, and the etching conditions are CHF3 40 sccm, SF6 10 sccm, O2 0 sccm, ICP Power 300W, and Bias Power 150W.

[0074] The S33 uses a plasma etching machine to remove any remaining resist. The etching conditions are: O2 80 sccm, Power 300W, 10 min.

[0075] S34 uses SEM or confocal microscope and other inspection equipment to test structural information and confirm consistency with the target structure. Figure 5 As shown, it is very consistent with the target structure.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for fabricating diffractive optical elements by controlling the thickness of the residual adhesive layer using a template, characterized in that: Includes the following steps, S1 establishes the structural compensation relationship between the template and the diffraction optical element, determines the etching rate of the residual adhesive layer and the pattern size on the template surface based on the diffraction grating size of different partitions of the diffraction optical element, and forms the template. ； w1:w n =v1:v n ; Where t is the etching time of the residual adhesive layer, d is the thickness of the residual adhesive layer on the minimum duty cycle partition, and w1, h1, and v1 are the diffraction grating linewidth, template pattern depth, and residual adhesive layer etching rate on the minimum duty cycle partition, respectively. n h n v n For the diffraction grating linewidth, template pattern depth, and residual adhesive layer etching rate on other partitions, n≥2; S2 uses the template obtained in S1 to imprint the pattern onto the imprintable medium, and after pressing the inorganic medium substrate onto the surface of the imprintable medium, the imprintable medium is imprinted and cured, demolded, and the thickness d of the residual adhesive layer on the minimum duty cycle partition is detected. Based on the etching time and etching rate obtained in S1, S3 synchronously etches the imprintable medium obtained in S2 in separate sections to simultaneously complete the etching of the residual adhesive layer.

2. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 1, characterized in that: In S1, the etching rate v1 of the residual adhesive layer on the minimum duty cycle partition is controlled to be 1.0~7.0 nm / s.

3. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 2, characterized in that: In S1, the inorganic dielectric of the inorganic dielectric substrate and the template material of the template are each independently selected from quartz, silicon, glass, YAG, CaF2, or sapphire.

4. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 1, characterized in that: In S2, the thickness d of the residual adhesive layer on the minimum duty cycle partition is controlled to be 10~100nm, and the imprintable medium is Delo OM6113 photoresist or Delo OM614 photoresist.

5. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 4, characterized in that: In S2, Includes the following steps, S21 Place the template and an evaporating dish containing 0.5~1.5mL of release agent into a vacuum drying oven, and evacuate to 10°C. -4 After Pa, stop pumping and maintain for 25-35 minutes. The release agent will then evaporate and cover the mold surface. S22 First, place the template obtained in S21 on a spin coater and fix it under vacuum adsorption. Then, drop 1~6mL of imprintable medium onto the pattern of the template. Then, spin coat at a low speed of 400~600rpm for 4~6s, followed by spin coat at a high speed of 2000~6000rpm for 50~70s. After spin coat is completed, bake at 100~180℃ for 1~3min. S23 First, place the inorganic dielectric substrate on a spin coater and fix it under vacuum adsorption. Then, drop 1-2 mL of tackifier onto the surface of the inorganic dielectric substrate. Then, spin coat at a low speed of 400-600 rpm for 4-6 seconds, followed by spin coat at a high speed of 2000-6000 rpm for 50-70 seconds. After spin coat is completed, bake at 100-180℃ for 1-3 minutes. S24 First, the template obtained in S22 is mounted on the imprinting machine. Then, the inorganic dielectric substrate obtained in S23 is mounted on the imprintable medium. The imprinting machine then applies a pressure of 100~1000N and performs 365nm UV curing under nitrogen protection with a curing energy of 300~600mJ / cm². 2 After UV curing, the mold is removed along the gap between the template and the inorganic substrate to transfer the imprintable medium onto the inorganic substrate. S25 uses an ellipsometry to detect the thickness of the residual adhesive layer d on the minimum duty cycle zone by measuring the thickness of the residual adhesive layer at the bottom of the thinnest groove in the unstructured area of ​​the imprintable medium or on the longitudinal section.

6. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 5, characterized in that: In S2, the release agent is 1H,1H,2H,2H-perfluorooctyltrichlorosilane.

7. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 1, characterized in that: In S2, the tackifier is AP3000 tackifier.

8. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 1, characterized in that: In S3, the etching conditions are controlled as follows: CHF3 10~40sccm, SF6 0~20sccm, O2 0~100sccm, ICPPower 100~300W, and Bias Power 0~100W.

9. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 1, characterized in that: S3 further includes etching the inorganic dielectric substrate after etching the residual adhesive layer, so as to form a diffraction grating on the surface of the inorganic dielectric substrate.

10. The method for processing diffractive optical elements by controlling the thickness of the residual adhesive layer using a template according to claim 1, characterized in that: S3 includes the following steps: S31 uses an ICP etching device to simultaneously etch the imprintable medium and inorganic medium substrate obtained in S2 in sections. Oxygen is used to etch the imprintable medium downward to a certain depth, so that the bottom of the groove is exposed to the inorganic medium substrate, which is convenient for the next step of pattern transfer etching. The etching conditions are ICP Power 200W, Bias 0, O2 60sccm. S32 continues to etch the surface of the inorganic dielectric substrate to form a diffraction grating on the surface of the inorganic dielectric substrate. The etching rate of the inorganic dielectric is 5.4 nm / s, and the etching conditions are CHF3 40 sccm, SF6 10 sccm, O2 0 sccm, ICP Power 300W, and BiasPower 150W. The S33 uses a plasma etching machine to remove any remaining resist. The etching conditions are: O2 80 sccm, Power 300W, 10 min.

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