CN117590507A - Blazed grating array structure based on nano-imprint and preparation method and application thereof - Google Patents

Abstract

The invention provides a blazed grating array structure based on nano imprinting and a preparation method and application thereof. The invention prepares a right-angle grating array structure on an elastic support substrate by adopting a nano imprinting technology to form an elastomer imprinting composite template; then the right angle grating array structure on the elastomer composite template is copied into an imprinting adhesive layer on the quartz glass substrate by utilizing a nano imprinting technology, then the right angle grating array structure is copied into a sacrificial layer on the quartz glass substrate by utilizing a dry etching technology, and then the blazed grating array structure with uniform appearance and stable mechanical property can be simply, conveniently and efficiently obtained by combining a vacuum coating technology and an inclination angle etching technology. The preparation method provided by the invention has the advantages of simple operation, low cost and easy mass production, can simply and efficiently control the blazed angle of the blazed grating by regulating and controlling the technological parameters of the preparation process, and has wide application prospects in the fields of optical elements, integrated optics and the like.

Description

Nanoimprint-based blazed grating array structure and its preparation method and application

Technical field

The invention relates to the field of micro-nano processing technology, and in particular to a nanoimprint-based blazed grating array structure and its preparation method and application.

Background technique

In the 1820s, German physicist Fraunhofer made the earliest gratings using metal filaments and screws. Since then, due to the development of processing technology and the need for precision instruments, micron and even nanoscale gratings have been designed and manufactured. . There are many types of gratings. They are divided into transmission gratings and reflection gratings according to their uses. They are also divided into flat gratings and concave gratings according to their shapes.

Diffraction grating is an important optical element in precision instruments such as monochromators and spectrometers. Plane gratings are usually used. The grating is simple in design and easy to process. However, the diffraction zero order of the plane grating coincides with the interference zero order, resulting in energy variation. waste. The blazed grating with a periodic tilt structure can concentrate most of the diffracted light into a single non-zero order, separating the diffraction and interference zero orders, thus avoiding energy waste and effectively solving this problem of planar gratings. In ultra-precision instruments, blazed gratings can be used as high-efficiency dispersion elements in spectrometers or as high-efficiency grating couplers in integrated optics. They not only have high diffraction efficiency, but can also significantly improve the sensitivity and resolution of the measurement system. rate and measurement range. Therefore, how to prepare stable and efficient blazed gratings has become a current research hotspot.

At present, the methods for preparing blazed gratings mainly include mechanical scribing, holographic ion beam etching, wet etching, and electron beam lithography. Among them, mechanical scribing and holographic ion beam etching are currently the main methods for producing large-area blazed gratings. The key to mechanical scribing lies in the angle and accuracy of the diamond cutter. However, since the radius of curvature of the diamond cutter cannot be reduced to zero, rounded corners will be formed on the actual grating, which will deviate from the ideal grating shape and affect the diffraction efficiency. The quality of blazed gratings in 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. At the same time, the height and duty cycle of the mask need to be precisely controlled, so in It is difficult to produce a photoresist mask that meets the requirements during processing. As for other preparation methods, on the one hand, they are cumbersome and time-consuming preparation processes, and on the other hand, they are expensive manufacturing costs, which limit their application in industrial production.

In view of this, how to prepare blazed gratings using a simple and low-cost method has become an urgent problem to be solved.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a nanoimprint-based blazed grating array structure and its preparation method and application. By combining nanoimprint technology and etching technology, the present invention prepares a blazed grating structure with uniform morphology and stable mechanical properties with a simple operating method and low cost. The blazed angle of the blazed grating is easy to control and can For use in the UV band.

In order to achieve the above objectives, the present invention provides a method for preparing a blazed grating array structure based on nanoimprinting, which includes the following steps:

S1. Use nanoimprint technology to prepare a right-angle grating array structure on an elastic support substrate to obtain an elastomer-imprinted composite template;

S2. Coat the sacrificial layer and the imprinting adhesive layer on the quartz glass substrate in sequence to obtain a pre-treated imprinting substrate;

S3. Use the elastomer imprinting composite template to perform nanoimprinting on the pretreatment imprinting base, so that the right-angle grating array structure on the elastomer imprinting composite template is imprinted onto the pretreatment imprinting base. From the embossing rubber layer, a first base is obtained;

S4. Use dry etching technology to etch the imprinting adhesive layer and the sacrificial layer in the first substrate in sequence until the quartz glass substrate is exposed at the grating groove to obtain a second substrate. ;

S5. Use vacuum coating technology to deposit a metal layer on the surface of the right-angle grating array structure of the second substrate, and then dissolve the sacrificial layer in the second substrate to obtain a third substrate;

S6. Using the deposited metal layer as a mask, use tilt-angle etching technology to etch the quartz glass substrate in the third substrate, and remove the metal layer to obtain a blazed grating array structure.

As a further improvement of the present invention, in step S1, the preparation method of the elastomer imprinted composite template includes the following steps:

S11. Coat imprint glue on the surface of the silicon substrate to obtain a pre-treated silicon substrate;

S12. Cover the surface of the pre-processed silicon substrate with an elastic support substrate. After the elastic support substrate fully absorbs the imprint glue, a pre-process imprint substrate is obtained;

S13. Use a right-angle grating silicon template to conduct nano-imprinting on the pre-processed imprint substrate to obtain an elastic support substrate with a right-angle grating array structure;

S14. Perform low surface energy treatment on the elastic support substrate with a right-angle grating array structure to obtain an elastomer imprinted composite template.

As a further improvement of the present invention, in step S14, the low surface energy treatment is performed in a vacuum environment, and the reagent used in the low surface energy treatment is perfluoroalkyl chlorosilane; the temperature of the low surface energy treatment is 80～95℃; the low surface energy treatment time is 3～5h.

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.

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 of polyvinyl alcohol and polyvinylpyrrolidone. One kind or two kinds are mixed, and the oil-soluble polymer material is polymethyl methacrylate.

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.

As a further improvement of the present invention, in step S6, the screen grid voltage used in 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 etched The time is 12 to 20 minutes.

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

In order to achieve the above object, the present invention also provides a blazed grating array structure based on nanoimprinting. The blazed grating array structure is prepared by using the preparation method described in any of the above technical solutions.

The invention also provides the application of the above-mentioned nanoimprint-based blazed grating array structure in the fields of optical elements and integrated optics.

The beneficial effects of the present invention are:

1. The method for preparing a blazed grating array structure based on nanoimprinting provided by the present invention adopts nanoimprinting technology to prepare a right-angle grating array structure on an elastic support substrate to form an elastomer imprinting composite template; and then utilizes nanoimprinting technology. Imprinting technology copies the right-angle grating array structure on the elastomer composite template into the imprinting adhesive layer on the quartz glass substrate, and then uses dry etching technology to copy the right-angle grating array structure into the 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.

2. The preparation method of the nanoimprint-based blazed grating array structure provided by the present invention has the advantages of simple operation, low cost, and easy mass production, and has broad application prospects in the fields of optical components and integrated optics. Based on the method provided by the present invention, the blaze angle of the blazed grating can be controlled simply and efficiently by regulating the height of the metal layer, the inclination angle of the ion beam etching, the etching time and other process parameters, thereby optimizing the parameters and improving its diffraction efficiency. The blaze angle of the blazed grating array structure obtained based on the preparation method provided by the invention can reach 7.2°, so that it can be applied in the ultraviolet band.

Description of drawings

Figure 1 is a schematic process flow diagram of a method for preparing a blazed grating array structure based on nanoimprinting provided by the present invention.

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

Reference signs

1-Quartz glass substrate; 2-Sacrificial layer; 3-Imprinting adhesive layer; 4-Elastomer embossing composite template; 5-Metal layer.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to the drawings and specific embodiments.

Here, 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 solution of the present invention are shown in the drawings, and the details related to the present invention are omitted. Invent other details that are less relevant.

Additionally, it should be noted that the terms "comprises," "comprises," or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements not only includes those elements, but also It also includes other elements not expressly listed or that are inherent to the process, method, article or equipment.

The invention provides a method for preparing a blazed grating array structure based on nanoimprinting. The process flow diagram is shown in Figure 1, which includes the following steps:

S1. Use UV nanoimprint technology to prepare a right-angle grating array structure on an elastic support substrate to obtain an elastomer imprinted composite template 4;

S2. Coat the sacrificial layer 2 and the imprinting adhesive layer 3 on the quartz glass substrate 1 in sequence to obtain a pretreated imprinting substrate;

S3. Use the elastomer imprinting composite template 4 to perform nanoimprinting on the pretreatment imprinting base, 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 pretreatment imprinting base. , get the first base;

S4. Use dry etching technology to etch the imprinting adhesive layer 3 and the sacrificial layer 2 in the first substrate in sequence until the quartz glass substrate 1 is exposed at the grating groove to obtain the second substrate;

S5. Use vacuum coating technology to deposit a metal layer 5 on the surface of the right-angle grating array structure of the second substrate, and then dissolve the sacrificial layer 2 in the second substrate to obtain a third substrate;

S6. Using the deposited metal layer 5 as a mask, use tilt-angle etching technology to etch the quartz glass substrate 1 in the third substrate, and remove the metal layer 5 to obtain a blazed grating array structure.

Preferably, in step S1, the preparation method of the elastomer imprinted composite template 4 includes the following steps:

S11. Coat imprint glue on the surface of the silicon substrate to obtain a pre-treated silicon substrate;

S12. Cover the elastic support substrate on the surface of the pre-processed silicon substrate. After the elastic support substrate fully absorbs the imprint glue, a pre-process imprint substrate is obtained;

S13. Use a right-angle grating silicon template to conduct nano-imprinting on the pre-processed imprint substrate to obtain an elastic support substrate with a right-angle grating array structure;

S14. Perform low surface energy treatment on the elastic support substrate with a right-angle grating array structure to obtain an elastomer imprinted composite template 4.

The present invention has no special regulations on 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 the present invention, the silicon substrate selected is preferably a p-doped n-type single-sided polished silicon wafer with a crystal orientation of <100>, a resistivity of 1-10Ωcm ^-2 and a thickness of 500±0.3μm.

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

In step S12, the present invention facilitates the nanoimprinting operation by using an elastic support substrate to adsorb the imprinting glue. The present invention has no special regulations on the source of the elastic support substrate used, and conventional commercially available products can be used. The glue absorption time of the elastic support substrate on the pre-treated silicon substrate is preferably 6 to 10 minutes, more preferably 8 minutes, so that the imprint glue can be completely filled into the elastic support substrate.

In step S13, the nanoimprinting process is preferably performed under a nitrogen atmosphere. Based on the selected UV-curable nanoimprinting glue, a right-angle grating silicon template is used to apply a certain pressure to the pre-processed imprinting substrate, and then exposed to ultraviolet light for 4 seconds. ~6min, preferably 5min, in order to copy the nano-pattern on the right-angle grating silicon template into the pre-processed imprint substrate to obtain an elastic support substrate with a right-angle grating array structure. The right-angle grating array structure on the elastic support substrate The shape and size are directly determined by the right-angle grating silicon template, and the right-angle grating silicon template can be selected according to needs. In some embodiments of the present invention, the line width, period and depth of the right-angle grating array structure in the right-angle grating silicon template used are preferably 277.5nm, 555nm and 110nm respectively.

In step S14, the low surface energy treatment is preferably performed in a vacuum environment, and perfluoroalkyl chlorosilane is used as a low surface energy reagent to perform low surface energy treatment on the elastic support substrate having 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 the right-angle grating array structure is also subjected to ozone treatment to introduce hydroxyl groups on the elastic support substrate.

In some embodiments of the present invention, the vacuum degree during low surface energy treatment is preferably 10 ^-3 Torr; the perfluoroalkyl chlorosilane is preferably 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane; the low surface energy The temperature that can be treated is preferably 80 to 95°C, more preferably 85 to 90°C; the time for low surface energy treatment is preferably 3 to 5 hours, more preferably 4 hours. This arrangement facilitates the vaporization of perfluoroalkyl chlorosilane, thereby utilizing the obtained perfluoroalkyl chlorosilane vapor to combine with the hydroxyl groups on the surface of the elastic support substrate having a right-angle grating array structure.

In step S2, the raw material of the sacrificial layer 2 is preferably a water-soluble polymer material or an oil-soluble polymer material, wherein the water-soluble polymer material is preferably one or a mixture of two of polyvinyl alcohol and polyvinylpyrrolidone, The oil-soluble polymer material is preferably polymethylmethacrylate. The coating method of the sacrificial layer 2 is preferably spin coating.

More specifically, in some embodiments of the present invention, the spin coating reagent used when spin coating the sacrificial layer 2 is an aqueous solution of a water-soluble polymer material or an oil solution of an oil-soluble polymer material. The mass concentration of the polymer material in the aqueous solution or oil solution is preferably 2% to 4%, and more preferably 3%. When performing spin coating, the spin coating speed is preferably 2500-3500 rpm, more preferably 3000 rpm, the spin-coating time is preferably 35-45 s, more preferably 40 s; the coating thickness of the sacrificial layer 2 is preferably 180nm to 200nm, more preferably 185 to 190nm.

In step S2, the raw material selection method of the embossing glue layer 3 is consistent with the selection method of the embossing glue in step S11, and will not be described again here. The coating method of the embossed rubber layer 3 is also preferably spin coating. The speed of the spin coating is preferably 2500-3500 rpm, more preferably 3000 rpm; the coating time is preferably 30-50 s, more preferably The coating thickness of the embossing adhesive layer 3 is preferably 70 to 90 nm, and more preferably 70 to 80 nm.

In step S3, the method of nanoimprinting the preprocessed imprinting substrate using the elastomer imprinting composite template 4 is consistent with the nanoimprinting method in step S13, and will not be described again. After the imprinting process in step S3, the first substrate obtained is a quartz glass substrate with a right-angle grating array structure in the imprinting adhesive layer 3.

In step S4, when dry etching technology is used to etch the imprinting adhesive layer 3 and the sacrificial layer 2 in the first substrate in sequence, the right-angle grating array in the imprinting adhesive layer 3 is a mask. In some embodiments of the present invention, the dry etching technology used is an inductively coupled plasma etching process, and the gas used to etch the imprinting rubber layer 3 is a mixed gas of O ₂ and CHF ₃ respectively. The etching gas used when etching the sacrificial layer 2 is pure O ₂ . Such an arrangement is conducive to sufficient etching of each layer.

The present invention has no special regulations on the above-mentioned etching path, and etching can be performed using a path that is well known to those skilled in the art to obtain a right-angle grating array structure. The present invention uses a right-angle grating array structure pattern constructed based on nanoimprint technology to etch the imprinting adhesive layer and the sacrificial layer in sequence. The second substrate obtained is a quartz glass substrate with a right-angle grating array structure in the sacrificial layer 2.

In step S5, the vacuum coating technology used is a technology that uses heating and evaporation to evaporate and vaporize the coating material under high vacuum conditions, so that the particles fly to the surface of the substrate and condense to form 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.

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

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

In step S6 , the method of removing the metal layer 5 is preferably reagent immersion and ultrasound, so as to dissolve the metal layer 5 through reagent immersion, and use ultrasound to promote the detachment of the metal layer 5 from the quartz glass substrate 1 . Among them, the reagent is preferably a mixed solution composed of ceric ammonium nitrate, acetic acid and pure water. In some embodiments of the present invention, the mass ratio of ceric ammonium nitrate, acetic acid and pure water in the mixed solution is preferably 8:22:70. Based on this mixed solution, it is beneficial to fully remove the deposited metal layer 5 .

Based on the above preparation method provided by the present invention, a blazed grating array structure based on nanoimprinting can be prepared, and the blazed grating array structure can be applied in the fields of optical elements and integrated optics.

Moreover, based on the above method provided by the present invention, the blazed grating can be controlled simply and efficiently by selecting the specifications of the right-angle grating silicon template, regulating the height of the metal layer, the inclination angle of the ion beam etching and the etching time and other related process parameters. blaze angle, thereby optimizing parameters to improve its diffraction efficiency. In some embodiments of the present invention, the blaze angle of the obtained blazed grating can reach 7.2°, and can be applied to the ultraviolet band.

The nanoimprint-based blazed grating array structure provided by the present invention and its preparation method and application will be described below with reference to specific examples.

Example 1

This embodiment provides a method for preparing a blazed grating array structure based on nanoimprinting, which includes the following steps:

S1. Use UV nanoimprint technology to prepare a right-angle grating array structure on an elastic support substrate to obtain an elastomer imprint composite template 4, which specifically includes the following steps:

S11. Coat imprint glue on the surface of the silicon substrate to obtain a pre-treated silicon substrate.

Among them, the specifications of the silicon substrate are: p-doped n-type single-sided polished silicon wafer, crystal orientation is <100>, resistivity is 1-10Ωcm ^-2 , and thickness is 500±0.3μm;

The coating method of the imprint glue is as follows: using UV nanoimprint glue with a mass concentration of 10% as the spin coating reagent, spin coating at a speed of 3000 rpm for 40 seconds, and the coating thickness is approximately 220 to 250 nm.

S12. Cover the surface of the pre-treated silicon substrate with the elastic support substrate. After absorbing glue for 8 minutes, allow the elastic support substrate to fully absorb the imprint glue to obtain the pre-treatment imprint substrate.

S13. Use a right-angle grating silicon template to conduct nano-imprinting on the preprocessed imprint substrate to obtain an elastic support substrate with a right-angle grating array structure.

Among them, the line width, period and depth of the right-angle grating array structure in the right-angle grating silicon template are preferably 277.5nm, 555nm and 110nm respectively. The nanoimprinting process is carried out in a nitrogen atmosphere. After applying a certain pressure to the pre-processed imprint substrate using a right-angle grating silicon template, it is exposed to ultraviolet light for 5 minutes so that the nano-pattern on the right-angle grating silicon template can be copied into the pre-processed pressure substrate. in the printing substrate.

S14. First, perform ozone treatment on the elastic support substrate with a right-angle grating array structure, and introduce hydroxyl groups on the elastic support substrate; then use 1H, 1H, 2H, 2H- in a vacuum system with a vacuum degree of 10 ^-3 Torr. Perfluorodecyltrichlorosilane was used to perform low surface energy treatment on the ozone-treated elastic support substrate with a right-angle grating array structure. The low surface energy treatment temperature was 90°C and the treatment time was 5 hours to obtain an elastomer imprinted composite template. 4.

The right-angle grating array structure in the elastomer imprinted composite template 4 has the same parameters as the right-angle grating array structure on the original right-angle grating silicon template, and the line width, period and depth are 277.5nm, 555nm and 110nm respectively.

S2. Coat the sacrificial layer 2 and the imprinting adhesive layer 3 on the quartz glass substrate 1 in sequence to obtain a pretreated imprinting substrate.

Among them, the coating method of the sacrificial layer 2 is: using a chlorobenzene solution of polymethyl methacrylate with a mass concentration of 3% as the spin coating reagent, spin coating at a speed of 3000 rpm for 40 s to obtain a coating thickness of 180 nm sacrificial layer 2;

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

S3. Use the elastomer imprinting composite template 4 to perform nanoimprinting on the pretreatment imprinting base, 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 pretreatment imprinting base. , the first substrate is obtained, which is a quartz glass substrate with a right-angle grating array structure in the imprinting adhesive layer 3 .

Among them, the nanoimprinting process is carried out in a nitrogen atmosphere. After applying a certain pressure to the pretreated imprinting substrate using the elastomer imprinting composite template 4, it is exposed to ultraviolet light for 5 minutes, so that the elastomer imprinting composite template 4 can be The rectangular grating array structure is replicated into the preprocessed imprint substrate.

S4. Use an inductively coupled plasma etching process to sequentially dry-etch the imprinting adhesive layer 3 and the sacrificial layer 2 in the first substrate until the quartz glass substrate 1 is exposed at the grating groove to obtain the second substrate, namely It is a quartz glass substrate with a right-angle grating array structure in the sacrificial layer 2.

Among them, the gas used to etch the imprinting rubber layer 3 is a mixed gas of O ₂ and CHF ₃ in a volume ratio of 1:1, and the etching gas used to etch the sacrificial layer 2 is Pure O ₂ .

S5. Use vacuum coating technology to deposit metal chromium on the surface of the right-angle grating array structure of the second substrate to form a metal layer 5 with a thickness of 120 nm. Then use acetone to dissolve the sacrificial layer 2 in the second substrate to obtain a third substrate.

S6. Use the deposited metal layer 5 as a mask and use tilt-angle etching technology to etch the quartz glass in the third substrate under the conditions of a screen grid voltage of 350V, a beam current of 90mA, and a tilt angle of the sample stage of 45°. The substrate 1 is etched for 20 minutes, and the metal layer 5 is removed using a mixed solvent composed of ammonium cerium nitrate, acetic acid and pure water in a mass ratio of 8:22:70 to obtain a blazed grating array structure. Its SEM picture is shown in Figure 2.

The blaze angle of the blaze grating array structure obtained in Example 1 was measured and calculated. The results showed that the blaze angle was 7.2° and could be applied to the ultraviolet band.

Moreover, the elastomer imprinted composite template 4 prepared in step S1 of this embodiment can be used repeatedly. The overall preparation method has the advantages of simple operation and low cost. The finally prepared blazed grating has stable mechanical properties, durability and durability. Abrasive, it can be used as optical components in precision instruments such as spectrometers and spectrometers, as well as in integrated optics and other fields. It has broad application prospects.

In summary, the present invention provides a nanoimprint-based blazed grating array structure and its preparation method and application. The present invention uses nano-imprint technology to prepare a right-angle grating array structure on an elastic support substrate to form an elastomer-imprinted composite template; and then uses nano-imprint technology to copy the right-angle grating array structure on the elastomer composite template to In the imprinting adhesive layer on the quartz glass substrate, dry etching technology is used to copy the right-angle grating array structure to the sacrificial layer on the quartz glass substrate, and then combined with vacuum coating technology and tilt angle etching technology, it can be simple and efficient A blazed grating array structure with uniform morphology and stable mechanical properties is obtained. The preparation method provided by the invention has the advantages of simple operation, low cost, and easy mass production. By regulating the process parameters of the preparation process, the blaze angle of the blazed grating can be controlled simply and efficiently, and has broad application prospects in the fields of optical elements and integrated optics. .

The above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently substituted. without departing from the spirit and scope of the technical solution of the present invention.

Claims (10)

1. The preparation method of the blazed grating array structure based on nano imprinting is characterized by comprising the following steps of:

s1, preparing a right-angle grating array structure on an elastic support substrate by adopting a nano imprinting technology to obtain an elastomer imprinting composite template;

s2, sequentially coating a sacrificial layer and an imprinting glue layer on the quartz glass substrate to obtain a pretreated imprinting substrate;

s3, nanoimprinting is carried out on the pretreated imprinting substrate by adopting the elastomer imprinting composite template, so that a right-angle grating array structure on the elastomer imprinting composite template is imprinted in the imprinting adhesive layer of the pretreated imprinting substrate, and a first substrate is obtained;

s4, sequentially etching the imprinting adhesive layer and the sacrificial layer in the first substrate by adopting a dry etching technology until the quartz glass substrate is exposed at the grating groove to obtain a second substrate;

s5, depositing a metal layer on the surface of the right-angle grating array structure of the second substrate by adopting a vacuum coating technology, and then dissolving the sacrificial layer in the second substrate to obtain a third substrate;

and S6, etching the quartz glass substrate in the third substrate by using the deposited metal layer as a mask and adopting an inclination angle etching technology, and removing the metal layer to obtain the blazed grating array structure.

2. The method for preparing a blazed grating array structure based on nano imprinting according to claim 1, wherein: in step S1, the method for preparing the elastomer imprinting composite template includes the following steps:

s11, coating imprinting glue on the surface of the silicon substrate to obtain a pretreated silicon substrate;

s12, covering an elastic support substrate on the surface of the pretreated silicon substrate, and obtaining a pretreated imprinting substrate after the elastic support substrate fully adsorbs the imprinting glue;

s13, nanoimprinting is carried out on the pretreated imprinting substrate by adopting a right-angle grating silicon template, and an elastic supporting substrate with a right-angle grating array structure is obtained;

s14, carrying out low surface energy treatment on the elastic support substrate with the right-angle grating array structure to obtain the elastomer imprinting composite template.

3. The method for preparing a blazed grating array structure based on nano imprinting according to claim 2, wherein: in step S14, the low surface energy treatment is performed in a vacuum environment, and the reagent used in the low surface energy treatment is perfluoroalkyl chlorosilane; the temperature of the low surface energy treatment is 80-95 ℃; the time of the low surface energy treatment is 3-5 h.

4. The method for preparing a blazed grating array structure based on nano imprinting according to claim 1, wherein: in the step S2, the coating thickness of the sacrificial layer is 180-200 nm, and the coating thickness of the imprinting glue layer is 70-90 nm.

5. The method for preparing a blazed grating array structure based on nano imprinting according to claim 1, wherein: in step S2, the 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 two of polyvinyl alcohol and polyvinylpyrrolidone, and the oil-soluble polymer material is polymethyl methacrylate.

6. The method for preparing a blazed grating array structure based on nano imprinting according to claim 1, wherein: in step S5, the metal in the metal layer is chromium; the deposition thickness of the metal layer is 110-130 nm.

7. The method for preparing a blazed grating array structure based on nano imprinting according to claim 1, wherein: in step S6, the screen grid voltage adopted in the inclination angle etching is 350-450V, the beam current is 88-92 mA, the inclination angle of the sample stage is 30-60 degrees, and the etching time is 12-20 minutes.

8. The method for preparing a blazed grating array structure based on nano imprinting according to claim 1, wherein: in step S6, the reagent for removing the metal layer is a mixed solution of ceric ammonium nitrate, acetic acid and water.

9. The blazed grating array structure based on nano imprinting is characterized in that: is prepared by the preparation method of any one of claims 1 to 8.

10. Use of a blazed grating array structure based on nanoimprinting as claimed in claim 9, characterized in that: the blazed grating array structure is applied to the fields of optical elements and integrated optics.