Blazed grating array structure based on nanoimprint and preparation method and application thereof

Abstract

The application provides a nanoimprint-based blazed grating array structure and a preparation method and application thereof. The application adopts the nanoimprint technology to prepare a right-angle grating array structure on an elastic supporting substrate, forms an elastic body imprint composite template; then the nanoimprint technology is used to copy the right-angle grating array structure on the elastic body composite template into an imprint adhesive layer on a quartz glass substrate, the dry etching technology is used to copy the right-angle grating array structure into a sacrifice layer on the quartz glass substrate, then the vacuum coating technology and the inclination angle etching technology are combined, and a blazed grating array structure with uniform morphology and stable mechanical performance can be simply and efficiently obtained. The preparation method has the advantages of simple operation, low cost and easy mass production, the blazed angle of the blazed grating can be simply and efficiently controlled by adjusting the process parameters in the preparation process, and the method has a wide application prospect in the fields of optical elements and integrated optics.

Description

Technical Field

[0001] This invention relates to the field of micro-nano fabrication technology, and in particular to a blazed grating array structure based on nanoimprinting, its fabrication method, and its application. Background Technology

[0002] In the 1820s, German physicist Franz Fraunhofer created the earliest optical grating using fine metal wires and screws. Subsequently, due to advancements in manufacturing technology and the need for precision instruments, micron- and even nanometer-scale gratings were designed and manufactured. There are many types of gratings, classified by application as transmissive and reflective gratings, and by shape as planar and concave gratings, among others.

[0003] Diffraction gratings are crucial optical components in precision instruments such as monochromators and spectrometers. Planar gratings are commonly used due to their simplicity and ease of fabrication; however, the zero order of diffraction coincides with the zero order of interference, resulting in energy waste. Blazed gratings with a periodically tilted structure can concentrate most of the diffracted light onto a single non-zero order, separating the diffraction and interference zero orders and thus avoiding energy waste, effectively solving this problem of planar gratings. In ultra-precision instruments, blazed gratings can be used as efficient dispersive elements in spectrometers and as efficient grating couplers in integrated optics, offering not only high diffraction efficiency but also significantly improving the sensitivity, resolution, and measurement range of the measurement system. Therefore, the fabrication of stable and efficient blazed gratings has become a current research hotspot.

[0004] Currently, methods for fabricating blazed gratings mainly include mechanical scribing, holographic ion beam etching, wet etching, and electron beam lithography. Among these, mechanical scribing and holographic ion beam etching are the primary methods for producing large-area blazed gratings. The key to mechanical scribing lies in the angle and precision of the diamond tool; however, because the radius of curvature of the diamond tool cannot be reduced to zero, rounded corners are formed on the actual fabricated grating, deviating from the ideal grating morphology and affecting diffraction efficiency. The quality of blazed gratings produced by holographic ion beam etching is limited by the quality of the photoresist mask, and the mask profile depends on the exposure and development conditions of the photoresist. Precise control of the mask height and duty cycle is also required, making it difficult to manufacture photoresist masks that meet the requirements during processing. As for other fabrication methods, their cumbersome and time-consuming processes, coupled with high manufacturing costs, limit their application in industrial production.

[0005] Therefore, how to prepare blazed gratings using a simple and low-cost method has become an urgent problem to be solved. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention aims to provide a blazed grating array structure based on nanoimprinting, its fabrication method, and its applications. This invention combines nanoimprinting technology with etching technology to fabricate a blazed grating structure with uniform morphology and stable mechanical properties using a simple operation method and at a low cost. Furthermore, the blaze angle of this blazed grating is easily adjustable, enabling its use in the ultraviolet band.

[0007] To achieve the above objectives, the present invention provides a method for fabricating a blazed grating array structure based on nanoimprinting, comprising the following steps:

[0008] S1. Using nanoimprinting technology, a right-angle grating array structure is prepared on an elastic support substrate to obtain an elastomer imprinted composite template.

[0009] S2. A sacrificial layer and an imprinting adhesive layer are sequentially coated on a quartz glass substrate to obtain a pretreated imprinting substrate.

[0010] S3. The pretreated imprinting substrate is nanoimprinted using the elastomer imprinting composite template, so that the right-angle grating array structure on the elastomer imprinting composite template is imprinted into the imprinting adhesive layer of the pretreated imprinting substrate to obtain the first substrate;

[0011] S4. Using dry etching technology, the imprinted adhesive layer and the sacrificial layer in the first substrate are etched sequentially until the quartz glass substrate is exposed at the grating groove, thus obtaining the second substrate;

[0012] S5. Using vacuum deposition technology, a metal layer is deposited on the surface of the right-angle grating array structure of the second substrate, and then the sacrificial layer in the second substrate is dissolved to obtain the third substrate;

[0013] S6. Using the deposited metal layer as a mask, the quartz glass substrate in the third substrate is etched using tilt etching technology, and the metal layer is removed to obtain a blazed grating array structure.

[0014] As a further improvement of the present invention, in step S1, the method for preparing the elastomer imprint composite template includes the following steps:

[0015] S11. Apply imprinting adhesive to the surface of the silicon substrate to obtain a pretreated silicon substrate;

[0016] S12. Cover the surface of the pretreated silicon substrate with an elastic support substrate. After the elastic support substrate has fully absorbed the imprinting adhesive, a pretreated imprinting substrate is obtained.

[0017] S13. Nanoimprinting is performed on the pretreated imprinting substrate using a right-angle grating silicon template to obtain an elastic support substrate with a right-angle grating array structure.

[0018] S14. The elastic support substrate with the right-angle grating array structure is subjected to low surface energy treatment to obtain an elastomer imprinted composite template.

[0019] As a further improvement of the present invention, in step S14, the low surface energy treatment is carried out in a vacuum environment, and the reagent used in the low surface energy treatment is a perfluoroalkylchlorosilane; the temperature of the low surface energy treatment is 80-95°C; and the time of the low surface energy treatment is 3-5 hours.

[0020] As a further improvement of the present invention, in step S2, the coating thickness of the sacrificial layer is 180-200 nm, and the coating thickness of the imprinting adhesive layer is 70-90 nm.

[0021] As a further improvement of the present invention, in step S2, the raw material of the sacrificial layer is a water-soluble polymer material or an oil-soluble polymer material; the water-soluble polymer material is one or a mixture of two of polyvinyl alcohol and polyvinylpyrrolidone, and the oil-soluble polymer material is polymethyl methacrylate.

[0022] As a further improvement of the present invention, in step S5, the metal in the metal layer is chromium; the deposition thickness of the metal layer is 110-130 nm.

[0023] As a further improvement of the present invention, in step S6, the screen voltage used for the tilt angle etching is 350-450V, the beam current is 88-92mA, the tilt angle of the sample stage is 30-60°, and the etching time is 12-20 minutes.

[0024] As a further improvement of the present invention, in step S6, the reagent for removing the metal layer is a mixed solution of cerium ammonium nitrate, acetic acid and water.

[0025] To achieve the above objectives, the present invention also provides a blazed grating array structure based on nanoimprinting, which is prepared by the preparation method described in any of the above technical solutions.

[0026] This invention also provides the application of the above-mentioned nanoimprint-based blazed grating array structure in the fields of optical components and integrated optics.

[0027] The beneficial effects of this invention are:

[0028] 1. The present invention provides a method for fabricating a blazed grating array structure based on nanoimprinting. By employing nanoimprinting technology, a right-angle grating array structure is fabricated on an elastic support substrate to form an elastomeric imprinting composite template. Then, using nanoimprinting technology, the right-angle grating array structure on the elastomeric composite template is copied into an imprinting adhesive layer on a quartz glass substrate. Next, dry etching technology is used to copy the right-angle grating array structure into a sacrificial layer on the quartz glass substrate. Combined with vacuum coating technology and tilt angle etching technology, a blazed grating array structure with uniform morphology and stable mechanical properties can be obtained simply and efficiently.

[0029] 2. The fabrication method of the blazed grating array structure based on nanoimprinting provided by this invention has the advantages of simple operation, low cost, and easy mass production, and has broad application prospects in optical components and integrated optics. Based on the method provided by this invention, the blaze angle of the blazed grating can be controlled simply and efficiently by adjusting process parameters such as the height of the metal layer, the tilt angle of the ion beam etching, and the etching time, thereby optimizing the parameters and improving its diffraction efficiency. The blazed grating array structure obtained by the fabrication method provided by this invention can achieve a blaze angle of 7.2°, which is suitable for application in the ultraviolet band. Attached Figure Description

[0030] Figure 1 A schematic diagram of the process flow for the fabrication method of the blazed grating array structure based on nanoimprinting provided by the present invention.

[0031] Figure 2 This is a SEM image of the blazed grating array structure prepared on a quartz glass substrate in Example 1.

[0032] Figure Labels

[0033] 1-Quartz glass substrate; 2-Sacrificial layer; 3-Imprinted adhesive layer; 4-Elastomer imprinted composite template; 5-Metal layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0036] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] This invention provides a method for fabricating a blazed grating array structure based on nanoimprinting, the process flow of which is shown in the schematic diagram below. Figure 1 As shown, it includes the following steps:

[0038] S1. Using ultraviolet nanoimprinting technology, a right-angle grating array structure is prepared on an elastic support substrate to obtain an elastomer imprinted composite template 4.

[0039] S2. A sacrificial layer 2 and an imprinting adhesive layer 3 are sequentially coated on a quartz glass substrate 1 to obtain a pretreated imprinting substrate.

[0040] S3. The pre-treated imprinting substrate is nanoimprinted using an elastomer imprinting composite template 4, so that the right-angle grating array structure on the elastomer imprinting composite template 4 is imprinted into the imprinting adhesive layer 3 of the pre-treated imprinting substrate to obtain the first substrate.

[0041] S4. Using dry etching technology, the imprinted adhesive layer 3 and the sacrificial layer 2 in the first substrate are etched sequentially until the quartz glass substrate 1 is exposed at the grating groove, thus obtaining the second substrate.

[0042] S5. Using vacuum deposition technology, a metal layer 5 is deposited on the surface of the right-angle grating array structure of the second substrate, and then the sacrificial layer 2 in the second substrate is dissolved to obtain the third substrate;

[0043] S6. Using the deposited metal layer 5 as a mask, the quartz glass substrate 1 in the third substrate is etched using tilt angle etching technology, and the metal layer 5 is removed to obtain the blazed grating array structure.

[0044] Preferably, in step S1, the preparation method of the elastomer imprint composite template 4 includes the following steps:

[0045] S11. Apply imprinting adhesive to the surface of the silicon substrate to obtain a pretreated silicon substrate;

[0046] S12. Cover the surface of the pretreated silicon substrate with the elastic support substrate. After the elastic support substrate has fully absorbed the imprinting adhesive, the pretreated imprinting substrate is obtained.

[0047] S13. Nanoimprinting is performed on the pretreated imprinting substrate using a right-angle grating silicon template to obtain an elastic support substrate with a right-angle grating array structure.

[0048] S14. The elastic support substrate with a right-angle grating array structure is subjected to low surface energy treatment to obtain the elastomer imprint composite template 4.

[0049] This invention does not specify the source of silicon in the silicon substrate used in step S11; silicon well-known to those skilled in the art can be used as the substrate. In some embodiments of this invention, the selected silicon substrate is preferably a p-doped n-type single-sided polished silicon wafer with a crystal orientation of <100> Resistivity 1-10 Ωcm -2 The thickness is 500±0.3μm.

[0050] In step S11, the imprinting adhesive used can be a conventional imprinting adhesive used in nanoimprinting processes. In some embodiments of the present invention, the imprinting adhesive is preferably a UV-curable nanoimprinting adhesive, so that the imprinting adhesive is cured by UV exposure. The method of coating the imprinting adhesive on the silicon substrate surface is preferably spin coating. In some embodiments of the present invention, the spin coating speed is preferably 2500-3500 rpm, more preferably 3000 rpm; the coating time is preferably 30-50 s, more preferably 40 s; and the coating thickness is preferably 220-250 nm, more preferably 220-230 nm.

[0051] In step S12, the present invention uses an elastic support substrate to adsorb the imprinting adhesive, which facilitates the nanoimprinting operation. The present invention does not specify the source of the elastic support substrate; conventional commercially available products are acceptable. The adsorption time of the elastic support substrate on the pretreated silicon substrate is preferably 6–10 min, more preferably 8 min, to ensure that the imprinting adhesive is completely filled into the elastic support substrate.

[0052] In step S13, the nanoimprinting process is preferably carried out under a nitrogen atmosphere. Based on the selected UV-curable nanoimprinting adhesive, after applying a certain pressure to the pretreated imprinting substrate using a right-angle grating silicon template, it is exposed to UV light for 4–6 minutes, preferably 5 minutes, so that the nanopattern on the right-angle grating silicon template is replicated into the pretreated imprinting substrate, obtaining an elastic support substrate with a right-angle grating array structure. The shape and size of the right-angle grating array structure on the elastic support substrate are directly determined by the right-angle grating silicon template, which can be selected as needed. In some embodiments of the present invention, the linewidth, period, and depth of the right-angle grating array structure in the right-angle grating silicon template are preferably 277.5 nm, 555 nm, and 110 nm, respectively.

[0053] In step S14, the low surface energy treatment is preferably performed in a vacuum environment, using a perfluoroalkylchlorosilane as a low surface energy reagent to treat the elastic support substrate with a right-angle grating array structure. Preferably, in some embodiments of the present invention, before performing the above-mentioned low surface energy treatment, the elastic support substrate with a right-angle grating array structure is also subjected to ozone treatment to introduce hydroxyl groups onto the elastic support substrate.

[0054] In some embodiments of the present invention, the vacuum degree during low surface energy processing is preferably 10. -3 Torr; the perfluoroalkylchlorosilane is preferably 1H,1H,2H,2H-perfluorodecyltrichlorosilane; the low surface energy treatment temperature is preferably 80–95°C, more preferably 85–90°C; the low surface energy treatment time is preferably 3–5 h, more preferably 4 h. This setting facilitates the vaporization of the perfluoroalkylchlorosilane, thereby utilizing the obtained perfluoroalkylchlorosilane vapor to combine with the hydroxyl groups on the surface of the elastic support substrate with a right-angle grating array structure.

[0055] In step S2, the raw material for the sacrificial layer 2 is preferably a water-soluble polymer or an oil-soluble polymer. The water-soluble polymer is preferably one or a mixture of polyvinyl alcohol and polyvinylpyrrolidone, and the oil-soluble polymer is preferably polymethyl methacrylate. The coating method for the sacrificial layer 2 is preferably spin coating.

[0056] More specifically, in some embodiments of the present invention, the spin-coating agent used for spin-coating the sacrificial layer 2 is an aqueous solution of a water-soluble polymer or an oil solution of an oil-soluble polymer. The mass concentration of the polymer in the aqueous or oil solution is preferably 2% to 4%, more preferably 3%. During spin-coating, the spin-coating rate is preferably 2500 to 3500 rpm, more preferably 3000 rpm, and the spin-coating time is preferably 35 to 45 seconds, more preferably 40 seconds; the coating thickness of the sacrificial layer 2 is preferably 180 nm to 200 nm, more preferably 185 to 190 nm.

[0057] In step S2, the selection method for the raw material of the imprinting adhesive layer 3 is the same as that in step S11, and will not be repeated here. The coating method of the imprinting adhesive layer 3 is preferably spin coating, and the spin coating speed is preferably 2500-3500 rpm, more preferably 3000 rpm; the coating time is preferably 30-50 s, more preferably 40 s; the coating thickness of the imprinting adhesive layer 3 is preferably 70-90 nm, more preferably 70-80 nm.

[0058] In step S3, the nanoimprinting method used on the pretreated imprinting substrate using the elastomer imprinting composite template 4 is the same as that in step S13, and will not be repeated here. After the imprinting process in step S3, the first substrate obtained is the quartz glass substrate with a right-angle grating array structure in the imprinting adhesive layer 3.

[0059] In step S4, when the imprinted resist layer 3 and the sacrificial layer 2 in the first substrate are etched sequentially using dry etching technology, the right-angle grating array in the imprinted resist layer 3 serves as a mask. In some embodiments of the present invention, the dry etching technology used is inductively coupled plasma etching (ICP-C). The gas used for etching the imprinted resist layer 3 is a mixture of O2 and CHF3, and the etching gas used for etching the sacrificial layer 2 is pure O2. This configuration facilitates thorough etching of each layer.

[0060] This invention does not specify a particular etching path; any path known to those skilled in the art for obtaining a right-angle grating array structure can be used for etching. This invention utilizes a right-angle grating array structure pattern constructed based on nanoimprint technology to sequentially etch the imprint adhesive layer and the sacrificial layer, resulting in a second substrate, which is a quartz glass substrate with a right-angle grating array structure in the sacrificial layer 2.

[0061] In step S5, the vacuum deposition technology used is a technique that evaporates the deposition material under high vacuum conditions by heating and vaporizing it, causing the particles to fly to the substrate surface and condense into a film. In some embodiments of the present invention, the metal in the deposited metal layer 5 is preferably chromium; the deposition thickness of the metal layer 5 is preferably 110-130 nm, more preferably 120 nm.

[0062] In step S5, after depositing the metal layer 5, the sacrificial layer 2 is preferably dissolved using the solvent acetone.

[0063] In step S6, the tilt-angle etching technique used is basically the same as the conventional ion beam etching process, except that the sample stage is changed from horizontal rotation etching to tilt-angle etching. Specifically, in some embodiments of the present invention, the grid voltage used for tilt-angle etching is preferably 350-450V, more preferably 350V; the beam current is preferably 88-92mA, more preferably 90mA; the tilt angle of the sample stage is preferably 30-60°, more preferably 45°; and the etching time is preferably 12-20 minutes, more preferably 15-20 minutes.

[0064] In step S6, the preferred method for removing the metal layer 5 is reagent soaking and ultrasonication. Soaking dissolves the metal layer 5, and ultrasonication promotes its detachment from the quartz glass substrate 1. The reagent is preferably a mixed solution of cerium ammonium nitrate, acetic acid, and pure water. In some embodiments of the present invention, the mass ratio of cerium ammonium nitrate, acetic acid, and pure water in this mixed solution is preferably 8:22:70. This mixed solution facilitates the thorough removal of the deposited metal layer 5.

[0065] Based on the above-mentioned preparation method provided by the present invention, a blazed grating array structure based on nanoimprinting can be prepared, which can be applied to optical components and integrated optics.

[0066] Furthermore, based on the method provided by this invention, the blaze angle of the blazed grating can be easily and efficiently controlled by adjusting relevant process parameters such as the selection of the specifications of the right-angle grating silicon template, the height of the metal layer, the tilt angle of the ion beam etching, and the etching time, thereby optimizing the parameters and improving its diffraction efficiency. In some embodiments of this invention, the obtained blaze angle of the blazed grating can reach 7.2°, which can be applied to the ultraviolet band.

[0067] The following describes the nanoimprint-based blazed grating array structure, its fabrication method, and its applications provided by the present invention, with reference to specific embodiments.

[0068] Example 1

[0069] This embodiment provides a method for fabricating a blazed grating array structure based on nanoimprinting, including the following steps:

[0070] S1. Using ultraviolet nanoimprinting technology, a right-angle grating array structure is prepared on an elastic support substrate to obtain the elastomer imprinted composite template 4. The specific steps include the following:

[0071] S11. Apply imprinting adhesive to the surface of the silicon substrate to obtain a pretreated silicon substrate.

[0072] The silicon substrate is specified as follows: a p-doped n-type single-sided polished silicon wafer with a crystal orientation of [missing information]. <100> Resistivity 1-10 Ωcm -2 The thickness is 500±0.3μm;

[0073] The coating method of the imprinting adhesive is as follows: using 10% UV nanoimprinting adhesive as the spin coating agent, spin coating is performed at a speed of 3000 rpm for 40 seconds, and the coating thickness is approximately 220-250 nm.

[0074] S12. Cover the surface of the pretreated silicon substrate with the elastic support substrate, and after absorbing the adhesive for 8 minutes, allow the elastic support substrate to fully absorb the imprinting adhesive to obtain the pretreated imprinting substrate.

[0075] S13. A right-angle grating silicon template is used to perform nanoimprinting on the pretreated imprinting substrate to obtain an elastic support substrate with a right-angle grating array structure.

[0076] The preferred linewidth, period, and depth of the right-angle grating array structure in the right-angle grating silicon template are 277.5 nm, 555 nm, and 110 nm, respectively. The nanoimprinting process is carried out in a nitrogen atmosphere. After applying a certain pressure to the pre-treated imprinting substrate using the right-angle grating silicon template, it is exposed to ultraviolet light for 5 minutes to allow the nanopatterns on the right-angle grating silicon template to be replicated into the pre-treated imprinting substrate.

[0077] S14. First, ozone treatment is performed on the elastic support substrate with a right-angle grating array structure to introduce hydroxyl groups onto the elastic support substrate; then, under a vacuum degree of 10... -3 In Torr's vacuum system, 1H,1H,2H,2H-perfluorodecyltrichlorosilane was used to perform low surface energy treatment on an ozone-treated elastic support substrate with a right-angle grating array structure. The low surface energy treatment temperature was 90℃ and the treatment time was 5h, resulting in an elastomer imprinted composite template 4.

[0078] The right-angle grating array structure in the elastomeric imprint composite template 4 has the same parameters as the right-angle grating array structure on the original right-angle grating silicon template, with linewidth, period, and depth of 277.5 nm, 555 nm, and 110 nm, respectively.

[0079] S2. A sacrificial layer 2 and an imprinting adhesive layer 3 are sequentially coated on a quartz glass substrate 1 to obtain a pretreated imprinting substrate.

[0080] The coating method of the sacrificial layer 2 is as follows: using a chlorobenzene solution of polymethyl methacrylate with a mass concentration of 3% as the spin coating agent, spin coating is performed at a speed of 3000 rpm for 40s to obtain a sacrificial layer 2 with a coating thickness of 180nm.

[0081] The coating method of the imprinting adhesive layer 3 is as follows: using a UV nanoimprinting adhesive with a mass concentration of 3% as a spin coating agent, spin coating is performed at a speed of 3000 rpm for 40s to obtain an imprinting adhesive layer 3 with a coating thickness of 75nm.

[0082] S3. The pre-treated imprinting substrate is nano-imprinted using an elastomer imprinting composite template 4, so that the right-angle grating array structure on the elastomer imprinting composite template 4 is imprinted into the imprinting adhesive layer 3 of the pre-treated imprinting substrate, thus obtaining the first substrate, which is a quartz glass substrate with a right-angle grating array structure in the imprinting adhesive layer 3.

[0083] The nanoimprinting process is carried out in a nitrogen atmosphere. After applying a certain pressure to the pre-treated imprinting substrate using an elastomer imprinting composite template 4, it is exposed to ultraviolet light for 5 minutes so that the right-angle grating array structure on the elastomer imprinting composite template 4 can be replicated into the pre-treated imprinting substrate.

[0084] S4. The imprinted adhesive layer 3 and the sacrificial layer 2 in the first substrate are sequentially dry etched using an inductively coupled plasma etching process until the quartz glass substrate 1 is exposed at the grating groove, thus obtaining the second substrate, which is the quartz glass substrate with a right-angle grating array structure in the sacrificial layer 2.

[0085] The gas used for etching the imprinted adhesive layer 3 is a mixed gas of O2 and CHF3 in a volume ratio of 1:1, and the etching gas used for etching the sacrificial layer 2 is pure O2.

[0086] S5. Using vacuum deposition technology, metallic chromium is deposited on the surface of the right-angle grating array structure of the second substrate to form a metal layer 5 with a thickness of 120nm. Then, acetone is used to dissolve the sacrificial layer 2 in the second substrate to obtain the third substrate.

[0087] S6. Using the deposited metal layer 5 as a mask, the quartz glass substrate 1 in the third substrate is etched using tilt-angle etching technology under the conditions of a grating voltage of 350V, a beam current of 90mA, and a sample stage tilt angle of 45°. The etching time is 20 minutes. The metal layer 5 is then removed using a mixed solvent composed of cerium ammonium nitrate, acetic acid, and pure water in a mass ratio of 8:22:70, resulting in a blazed grating array structure. Its SEM image is shown below. Figure 2 As shown.

[0088] The blaze angle of the blazed grating array structure obtained in Example 1 was measured and calculated. The results showed that its blaze angle was 7.2°, which can be applied to the ultraviolet band.

[0089] Furthermore, the elastomer imprinted composite template 4 prepared in step S1 of this embodiment can be reused multiple times. The overall preparation method has the advantages of simple operation and low cost. The final blazed grating has stable mechanical properties, durability and wear resistance, and can be used as an optical element in precision instruments such as spectrometers and spectrometers, as well as in integrated optics and other fields, with broad application prospects.

[0090] In summary, this invention provides a blazed grating array structure based on nanoimprinting, its fabrication method, and its applications. This invention utilizes nanoimprinting technology to fabricate a right-angled grating array structure on an elastic support substrate, forming an elastomeric imprinted composite template. Then, using nanoimprinting, the right-angled grating array structure on the elastomeric composite template is copied into an imprinted adhesive layer on a quartz glass substrate. Next, dry etching is used to copy the right-angled grating array structure into a sacrificial layer on the quartz glass substrate. Finally, combining vacuum deposition and tilt-angle etching techniques, a blazed grating array structure with uniform morphology and stable mechanical properties can be obtained simply and efficiently. The fabrication method provided by this invention has the advantages of simple operation, low cost, and easy mass production. By controlling the process parameters, the blaze angle of the blazed grating can be controlled simply and efficiently, showing broad application prospects in optical components and integrated optics.

[0091] 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.

Claims

1. A method for fabricating a blazed grating array structure based on nanoimprinting, characterized in that, Includes the following steps: S1. Using nanoimprinting technology, a right-angle grating array structure is prepared on an elastic support substrate to obtain an elastomer imprinted composite template. S2. A sacrificial layer and an imprinting adhesive layer are sequentially coated on a quartz glass substrate to obtain a pretreated imprinting substrate. S3. Nanoimprinting is performed on the pretreated imprinting substrate using the elastomer imprinting composite template, so that the right-angle grating array structure on the elastomer imprinting composite template is imprinted into the imprinting adhesive layer of the pretreated imprinting substrate to obtain the first substrate; S4. Using dry etching technology, the imprinted adhesive layer and the sacrificial layer in the first substrate are etched sequentially, using the right-angle grating array in the imprinted adhesive layer as a mask, until the quartz glass substrate is exposed at the grating groove, to obtain the second substrate. S5. Using vacuum deposition technology, a metal layer is deposited on the surface of the right-angle grating array structure of the second substrate, and then the sacrificial layer in the second substrate is dissolved to obtain the third substrate; S6. Using the deposited metal layer as a mask, the quartz glass substrate in the third substrate is etched using tilt etching technology, and the metal layer is removed to obtain a blazed grating array structure.

2. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 1, characterized in that: In step S1, the method for preparing the elastomer imprint composite template includes the following steps: S11. Apply imprinting adhesive to the surface of the silicon substrate to obtain a pretreated silicon substrate; S12. Cover the surface of the pretreated silicon substrate with an elastic support substrate. After the elastic support substrate has fully absorbed the imprinting adhesive, a pretreated imprinting substrate is obtained. S13. Nanoimprinting is performed on the pretreated imprinting substrate using a right-angle grating silicon template to obtain an elastic support substrate with a right-angle grating array structure. S14. The elastic support substrate with the right-angle grating array structure is subjected to low surface energy treatment to obtain an elastomer imprinted composite template.

3. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 2, characterized in that: In step S14, the low surface energy treatment is carried out in a vacuum environment, and the reagent used in the low surface energy treatment is a perfluoroalkylchlorosilane; the temperature of the low surface energy treatment is 80~95℃; and the time of the low surface energy treatment is 3~5h.

4. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 1, characterized in that: In step S2, the coating thickness of the sacrificial layer is 180~200nm, and the coating thickness of the imprinting adhesive layer is 70~90nm.

5. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 1, characterized in that: In step S2, the raw material of the sacrificial layer is a water-soluble polymer material or an oil-soluble polymer material; the water-soluble polymer material is one or a mixture of two of polyvinyl alcohol and polyvinylpyrrolidone, and the oil-soluble polymer material is polymethyl methacrylate.

6. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 1, characterized in that: In step S5, the metal in the metal layer is chromium; the deposition thickness of the metal layer is 110~130nm.

7. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 1, characterized in that: In step S6, the screen voltage used for the tilt etching is 350~450V, the beam current is 88~92mA, the tilt angle of the sample stage is 30~60°, and the etching time is 12~20 minutes.

8. The method for fabricating a blazed grating array structure based on nanoimprinting according to claim 1, characterized in that: In step S6, the reagent used to remove the metal layer is a mixed solution of cerium ammonium nitrate, acetic acid, and water.

9. A blazed grating array structure based on nanoimprinting, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 8.

10. An application of the nanoimprint-based blazed grating array structure as described in claim 9, characterized in that: The blazed grating array structure is used in the fields of optical components and integrated optics.

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