Method for obtaining high resolution patterns with different illumination modes

Abstract

The present disclosure provides a method for obtaining high-resolution patterns by using different illumination modes, and relates to the field of photolithography technology, and the method comprises the following steps: forming a negative photosensitive film layer, a positive photosensitive film layer and a metal enhancement layer which are sequentially stacked on a substrate; using a first illumination mode, exposing the positive photosensitive film layer based on a mask plate; using a second illumination mode, exposing the negative photosensitive film layer based on the mask plate; the illumination wavelengths of the first illumination mode and the second illumination mode are the same, and the first focal depth of the first illumination mode is different from the second focal depth of the second illumination mode; sequentially developing the exposed positive photosensitive film layer and the exposed negative photosensitive film layer to obtain pattern structures generated by twice exposure; and transferring the pattern structures generated by twice exposure to the substrate to obtain high-resolution patterns.

Description

Technical Field

[0001] This disclosure relates to the field of photolithography, and more particularly to a method for obtaining high-resolution patterns using different illumination modes. Background Technology

[0002] As a critical layer in microelectronic devices, the gate pattern's feature size directly represents the processing node of nanolithography. The fabrication of high-resolution gates has gradually become a research hotspot in the semiconductor device field. When the gate feature size is less than 50 nm, various resolution enhancement techniques have emerged, among which double exposure technology has found widespread application in the fabrication of critical layers in semiconductor devices. Double exposure technology splits the same critical layer pattern onto two masks, using precise alignment for two exposures, thus enabling the fabrication of gate critical layer patterns with even smaller feature sizes. However, as the feature size further decreases, the requirements for alignment accuracy in double exposure become increasingly stringent, posing a greater challenge to precision alignment technology. Summary of the Invention

[0003] In view of this, embodiments of the present disclosure provide a method for obtaining high-resolution patterns using different illumination modes, comprising: forming at least a negative photosensitive film layer, a positive photosensitive film layer, and a metal reinforcement layer sequentially stacked on a substrate, wherein the negative photosensitive film layer is close to the substrate; exposing the positive photosensitive film layer based on a mask using a first illumination mode, and exposing the negative photosensitive film layer based on a mask using a second illumination mode, wherein the illumination wavelengths of the first illumination mode and the second illumination mode are the same, and the first depth of focus of the first illumination mode is different from the second depth of focus of the second illumination mode; developing the exposed positive photosensitive film layer and the exposed negative photosensitive film layer to obtain a pattern structure generated by the two exposures; and transferring the pattern structure generated by the two exposures to the substrate to obtain a high-resolution pattern.

[0004] According to embodiments of this disclosure, the first illumination mode includes normal incident illumination, the second illumination mode includes off-axis illumination, and the illumination wavelengths of the first and second illumination modes include one of 365 nm, 248 nm, 193 nm, and 13.5 nm; the first depth of focus is less than the second depth of focus.

[0005] According to embodiments of this disclosure, negative photosensitive film layers and positive photosensitive film layers are prepared by coating, spraying, or fumigation. The material of the positive photosensitive film layer includes at least one of AR series photoresist, XT series photoresist, and PHS photoresist. The thickness of the positive photosensitive film layer is 20 nm to 50 nm. The material of the negative photosensitive film layer includes at least one of PMMA photoresist, SU-8 photoresist, and polyester photoresist. The thickness of the negative photosensitive film layer is 50 nm to 1000 nm.

[0006] According to embodiments of this disclosure, a metal reinforcement layer is prepared by means of thermal evaporation, electron beam evaporation, magnetron sputtering deposition, chemical vapor deposition, or coating, wherein the material of the metal reinforcement layer includes an excited surface plasma material.

[0007] According to embodiments of this disclosure, the material of the light-blocking layer of the mask includes at least one of chromium, silicon, and molybdenum, the mask pattern height of the mask is 30 nm to 50 nm, the period of the mask pattern is 40 nm to 300 nm, the duty cycle of the mask pattern is 3:1 to 1:1, and the critical dimension of the mask pattern is 20 nm to 150 nm.

[0008] According to embodiments of this disclosure, the exposure dose of normal incident illumination is 20 mJ / cm². 2 -200 mJ / cm 2 The slit width of the patterned structure on the positive photosensitive film layer is greater than half the period of the mask pattern.

[0009] According to embodiments of this disclosure, off-axis illumination is used with an illumination angle of 5° to 90°, and the exposure dose of the off-axis illumination is 50 mJ / cm². 2 -300 mJ / cm 2 The linewidth of the pattern structure on the negative photosensitive film layer is less than half the period of the mask pattern, and the pattern structure on the negative photosensitive film layer is the opposite of the structure of the mask pattern on the mask.

[0010] According to embodiments of this disclosure, developing an exposed positive photosensitive film layer and an exposed negative photosensitive film layer includes: developing the positive photosensitive film layer with a positive developer, the positive developer including at least one of AR300-35 developer, TMAH developer, and NaOH developer; and developing the negative photosensitive film layer with a negative developer, the negative developer including at least one of n-butyl acetate developer, ethyl 3-ethoxypropionate developer, and 2-heptanone developer.

[0011] According to embodiments of this disclosure, transferring a patterned structure generated by two exposures onto a substrate includes: transferring the patterned structure generated by two exposures onto a substrate using ion beam etching, reactive ion etching, or inductively coupled plasma etching.

[0012] According to embodiments of this disclosure, the substrate includes a transparent substrate or an opaque substrate; the transparent substrate includes a quartz substrate, a glass substrate, or a sapphire substrate; the opaque substrate includes a silicon substrate.

[0013] The method for obtaining high-resolution images using different lighting modes provided according to the embodiments of this disclosure has at least the following technical effects:

[0014] This method leverages the varying depths of focus across different illumination modes, enabling the fabrication of high-tech node gate patterns using only a single mask and without relying on precise alignment techniques. It achieves nanoscale patterns with double the resolution, effectively addressing the current limitations of dual-exposure techniques that heavily depend on precise alignment for high-resolution pattern fabrication. Furthermore, it reduces the number of processing masks, lowering the difficulty and cost of fabrication while maintaining high efficiency. This method can be applied not only to various novel nanodevices but also to the fabrication of critical layers in high-tech semiconductor chips. Attached Figure Description

[0015] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0016] Figure 1 A flowchart illustrating a method for obtaining high-resolution graphics using different lighting modes according to an embodiment of the present disclosure is shown schematically.

[0017] Figure 2 The diagram schematically illustrates the structural diagrams corresponding to each step in a method for obtaining high-resolution graphics using different lighting modes according to embodiments of the present disclosure. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0020] Similarly, to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the above description of exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] To address the limitations of existing double-exposure techniques in processing high-tech node graphic structures due to the constraints of precision alignment, embodiments of this disclosure aim to provide a method for obtaining high-resolution graphics using different illumination modes.

[0023] like Figure 1 As shown, the method for obtaining high-resolution graphics using different lighting modes in this embodiment may include operations S110 to S140.

[0024] In operation S110, at least a negative photosensitive film layer, a positive photosensitive film layer, and a metal reinforcement layer are formed sequentially on the substrate.

[0025] In operation S120, the first illumination mode is used to expose the positive photosensitive film layer based on the mask, and the second illumination mode is used to expose the negative photosensitive film layer based on the mask.

[0026] In operation S130, the positively and negatively exposed photosensitive film layers after exposure are developed to obtain the pattern structure produced by the two exposures.

[0027] In operation S140, the graphic structure generated by the two exposures is transferred to the substrate.

[0028] In embodiments of this disclosure, the negative photosensitive film layer is close to the substrate. The first illumination mode and the second illumination mode have the same illumination wavelength, but the first depth of focus of the first illumination mode and the second depth of focus of the second illumination mode are different. This method utilizes the characteristic that the first illumination mode and the second illumination mode have different depths of focus, and based on the same illumination wavelength, it can realize the fabrication of high-tech node gate pattern structures using only the same mask and without relying on precise alignment techniques.

[0029] In the embodiments of this disclosure, a metal reinforcement layer is prepared on the second photosensitive layer, which can enhance the exposure effect and improve the exposure quality.

[0030] In some embodiments, the first illumination mode includes positive incident illumination, and the second illumination mode includes off-axis illumination. The illumination wavelengths of the first and second illumination modes include one of 365 nm, 248 nm, 193 nm, and 13.5 nm. The first depth of focus is smaller than the second depth of focus. The exposed areas of the positive photosensitive film are removed after development, while the unexposed areas are retained. The exposed areas of the negative photosensitive film are retained after development, while the unexposed areas are removed.

[0031] This method utilizes the shallow depth of field characteristic of normal incident illumination, which only exposes the surface photosensitive film layer, while the underlying photosensitive layer cannot reach the required depth of field. A suitable nanomask pattern is selected to expose the second photosensitive film layer in the aforementioned multilayer film. Alternatively, using the same mask, the normal incident illumination is replaced with off-axis illumination. Taking advantage of the long depth of field characteristic of off-axis illumination, the surface photosensitive layer can be penetrated to expose the underlying photosensitive layer, thus achieving the exposure of the first photosensitive film layer.

[0032] In some embodiments, the substrate used in operation S110 may include a transparent substrate such as a quartz substrate, a glass substrate, or a sapphire substrate, or an opaque substrate such as a silicon substrate.

[0033] In some embodiments, operation S110 may further include: preparing a negative photosensitive film layer and a positive photosensitive film layer by means of coating, spraying or fumigation.

[0034] The material of the positive photosensitive film layer may include at least one of AR series photoresist, XT series photoresist, and PHS photoresist; the thickness of the positive photosensitive film layer may be 20 nm to 50 nm.

[0035] The material of the negative photosensitive film layer may include at least one of PMMA photoresist, SU-8 photoresist, and polyester photoresist, and the thickness of the negative photosensitive film layer may be 50 nm to 1000 nm.

[0036] In some embodiments, operation S110 may further include: preparing a metal reinforcement layer using methods such as thermal evaporation, electron beam evaporation, magnetron sputtering deposition, chemical vapor deposition, or coating.

[0037] The materials of the metal reinforcement layer include materials that excite surface plasmons, such as Ag, Al, Au, etc.

[0038] In some embodiments, the light-blocking layer material of the mask in operation S120 may include at least one of chromium, silicon, and molybdenum. The mask pattern height can be 30 nm to 50 nm, the mask pattern period can be 40 nm to 300 nm, the mask pattern duty cycle can be 3:1 to 1:1, and the mask pattern critical dimension (CD) is 20 nm to 150 nm. It should be noted that the duty cycle refers to the ratio of line width to slot width, the period is expressed as pitch, half-period as half-pitch, and the critical dimension as CD (line width). The slot width is the difference between the period pitch and the critical dimension CD. When the duty cycle is 1:1, CD equals half-pitch; when the duty cycle is 3:1, CD is three times the slot width. The period of the mask pattern refers to the distance between the repeating pattern units on the mask. This distance has a certain regularity in space, making the entire mask pattern exhibit a periodic structure. The critical dimension of a mask pattern refers to a special line pattern designed to reflect the width of characteristic lines of an integrated circuit in order to evaluate and control the pattern processing accuracy of the process in integrated circuit photomask manufacturing and photolithography.

[0039] In some embodiments, the exposure dose of the normal incident illumination in operation S120 is 20 mJ / cm². 2 ~200 mJ / cm 2 By controlling the exposure dose of the positive incident illumination, the slit width of the patterned structure on the positive photosensitive film layer is greater than half the period of the mask pattern.

[0040] In some embodiments, the illumination angle of the off-axis illumination in operation S120 is 5° to 90°, and the exposure dose of the off-axis illumination can be 50 mJ / cm². 2 ~300 mJ / cm 2 By controlling the exposure dose of off-axis illumination, the linewidth of the pattern structure on the negative photosensitive film layer is less than half the period of the mask pattern. Since it is a negative photosensitive material, the pattern structure on the negative photosensitive film layer is the opposite of the structure of the mask pattern.

[0041] In some embodiments, developing the exposed positive photosensitive film layer and the exposed negative photosensitive film layer in operation S130 may include:

[0042] A positive developer is used to develop the positively sensitized film layer to obtain a linewidth pattern structure with a slit width exceeding half of the mask cycle. The positive developer includes at least one of AR300-35 developer, TMAH developer, and NaOH developer.

[0043] The negative photosensitive film layer is developed using a negative developer to obtain a pattern structure that is the opposite of the mask pattern. The negative developer includes at least one of n-butyl acetate developer, ethyl 3-ethoxypropionate developer, and 2-heptanone developer.

[0044] In some embodiments, transferring the patterned structure generated by the two exposures to the substrate in operation S140 may include:

[0045] Ion beam etching (IBE), reactive ion etching (RIE), inductively coupled plasma etching (ICP) or other dry etching transfer methods are used to transfer the patterned structure generated by two exposures to the substrate, thereby obtaining a patterned structure with doubled resolution on the substrate.

[0046] To more clearly illustrate the method for obtaining high-resolution images using different lighting modes provided in the embodiments of this disclosure, the following is combined with... Figure 2 Here are three specific examples to illustrate this.

[0047] Example 1:

[0048] The method for obtaining high-resolution images using different lighting modes provided in this embodiment may include the following steps:

[0049] Step (1): Select a silicon substrate as substrate 1. Spin-coat PMMA negative photosensitive material onto substrate 1 to form a negative photosensitive film layer 2 with a thickness of 50 nm and a baking temperature of 120 ℃. Spin-coat AR-P3170 positive photosensitive material to form a positive photosensitive film layer 3 with a thickness of 30 nm and a baking temperature of 100 ℃. Deposit Ag to form a metal reinforcement layer 4 using thermal evaporation deposition with a thickness of 10 nm. The resulting structure is as follows. Figure 2 As shown in Figure a.

[0050] Step (2) uses a mercury lamp with an illumination wavelength of 365 nm. The mask blocking layer 5 is made of metallic Cr. The height of the mask pattern 6 is 40 nm, the period of the mask pattern 6 is 200 nm, the duty cycle of the mask is 3:1, and the mask line size is 150 nm. Exposure is performed with the mask and the metal reinforcement layer 4 in close contact. The exposure dose is 100 mJ / cm². 2This allows the positive photosensitive film layer 3 to be photosensitive. The resulting structure is as follows. Figure 2 As shown in b.

[0051] Step (3) Change the off-axis illumination and perform a second off-axis illumination exposure at the same illumination wavelength. The off-axis illumination angle is approximately 30°, and the exposure dose is 100 mJ / cm. 2 This allows the negative photosensitive film layer 2 to be photosensitive. The resulting structure is as follows. Figure 2 As shown in c.

[0052] Step (4) Remove the surface metal reinforcement layer 4 using adhesive tape, and develop the positive photosensitive film layer 3 of AR-P3170 using 300-35 developer to obtain a pattern structure with a slit width of 120 nm. Different slit widths can be obtained in the positive photosensitive film layer 3 by controlling the exposure dose. The prepared structures are shown below. Figure 2 As shown in Figure d. Next, the negative photosensitive film layer 2 was developed using n-butyl acetate, resulting in a grating structure with a pattern size of 50 nm on the negative photosensitive film layer 2. The prepared structure is shown in Figure d. Figure 2 As shown in e.

[0053] Step (5) uses IBE etching to transfer the pattern in the negative photosensitive layer 2 and the positive photosensitive layer 3 to the substrate 1. The negative photosensitive layer 2 and the positive photosensitive layer 3 are then removed, thereby realizing a wire grid pattern structure with a period of 100 nm and a linewidth of 50 nm on the silicon substrate 1. The fabricated structure is shown in the figure. Figure 2 As shown in f.

[0054] Example 2:

[0055] The method for obtaining high-resolution images using different lighting modes provided in this embodiment may include the following steps:

[0056] Step (1) Select a quartz substrate as substrate 1. Spin-coat SU-8 negative photosensitive material onto substrate 1 to form a negative photosensitive film layer 2 with a thickness of 40 nm and a baking temperature of 120 ℃. Spin-coat AR3170 positive photosensitive material to form a positive photosensitive film layer 3 with a thickness of 25 nm and a baking temperature of 100 ℃. Deposit Al to form a metal reinforcement layer 4 using magnetron sputtering, with a deposition thickness of 15 nm. The resulting structure is as follows. Figure 2 As shown in Figure a.

[0057] Step (2) uses a mercury lamp with an illumination wavelength of 365 nm. The mask blocking layer 5 is made of metallic Cr. The height of the mask pattern 6 is 30 nm, the period of the mask pattern 6 is 120 nm, the duty cycle of the mask is 2:1, and the mask line size is 80 nm. Exposure is performed with the mask and the metal reinforcement layer 4 in close contact. The exposure dose is 120 mJ / cm. 2 This allows the positive photosensitive film layer 3 to be photosensitive. The resulting structure is as follows. Figure 2 As shown in b.

[0058] Step (3) Change the off-axis illumination and perform a second off-axis illumination exposure at the same illumination wavelength. The off-axis illumination angle is approximately 60°, and the exposure dose is 200 mJ / cm. 2 This allows the negative photosensitive film layer 2 to be photosensitive. The resulting structure is as follows. Figure 2 As shown in c.

[0059] Step (4) involves removing the surface metal reinforcement layer 4 using phosphoric acid, and developing the positive photosensitive film layer 3 using a 300-35 developer to obtain a patterned structure with a slit width of 80 nm. Different slit widths can be obtained in the positive photosensitive film layer 3 by controlling the exposure dose. The prepared structures are shown below. Figure 2 As shown in Figure d. Next, ethyl 3-ethoxypropionate was used to develop the negative photosensitive film layer 2, obtaining a grating structure with a pattern size of 40 nm on the negative photosensitive film layer 2. The prepared structure is shown in Figure d. Figure 2 As shown in e.

[0060] Step (5) uses RIE etching to transfer the pattern in the negative photosensitive film layer 2 and the positive photosensitive film layer 3 to the silicon substrate 1, and removes the negative photosensitive film layer 2 and the positive photosensitive film layer 3, thereby realizing a grid pattern structure with a period of 60 nm and a linewidth of 30 nm on the substrate.

[0061] Example 3:

[0062] The method for obtaining high-resolution images using different lighting modes provided in this embodiment may include the following steps:

[0063] Step (1) Select a sapphire substrate as substrate 1. Spin-coat a polyester-based negative photosensitive material onto substrate 1 as negative photosensitive film layer 2, with a thickness of 30 nm and a baking temperature of 120 ℃. Spin-coat an AZ1500 positive photosensitive material as positive photosensitive film layer 3, with a thickness of 20 nm and a baking temperature of 90 ℃. Deposit Au to form a metal reinforcement layer 4 using electron beam deposition, with a deposition thickness of 20 nm. The resulting structure is as follows. Figure 2 As shown in Figure a.

[0064] Step (2) uses a mercury lamp with an illumination wavelength of 193 nm. The mask blocking layer 5 is made of molybdenum. The height of the mask pattern 6 is 40 nm, the period of the mask pattern 6 is 88 nm, the duty cycle of the mask is 3:1, and the mask line size is 66 nm. Exposure is performed with the mask and the metal reinforcement layer 4 in close contact. The exposure dose is 50 mJ / cm. 2 The positive photosensitive film layer 3 is then photosensitive. The resulting structure is as follows. Figure 2 As shown in b.

[0065] Step (3) Change the off-axis illumination and perform a second off-axis illumination exposure at the same illumination wavelength. The off-axis illumination angle is approximately 50°, and the exposure dose is 50 mJ / cm. 2 This allows the negative photosensitive film layer 2 to be photosensitive. The resulting structure is as follows. Figure 2 As shown in c.

[0066] Step (4) Remove the surface metal reinforcement layer 4 using adhesive tape, and develop the positive photosensitive film layer 3 using TMAH developer to obtain a pattern structure with a slit width of 60 nm. By controlling the exposure dose, pattern structures with different slit widths can be obtained in the positive photosensitive film layer 3. The prepared structure is as follows: Figure 2 As shown in Figure d. Next, 2-heptanone was used to develop the negative photosensitive film layer 2, obtaining a grating structure with a pattern size of 22 nm on the negative photosensitive film layer 2. The prepared structure is shown in Figure d. Figure 2 As shown in e.

[0067] Step (5) uses ICP etching to transfer the pattern in the negative photosensitive film layer 2 and the positive photosensitive film layer 3 to the substrate 1, and removes the negative photosensitive film layer 2 and the positive photosensitive film layer 3, thereby realizing a grid pattern structure with a period of 44 nm and a linewidth of 22 nm on the substrate 1.

[0068] It should be noted that the specific parameters, material types, and processing methods involved in the above examples are all for the purpose of more clearly illustrating the method of obtaining high-resolution graphics using different lighting modes provided in the embodiments of this disclosure, and are not intended to limit this disclosure.

[0069] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above are merely preferred embodiments and the technical principles applied. Those skilled in the art will understand that this disclosure is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this disclosure. Therefore, although this disclosure has been described in detail through the above embodiments, this disclosure is not limited to the above embodiments. More other equivalent embodiments may be included without departing from the concept of this disclosure, all of which fall within the scope of protection of this disclosure.

Claims

1. A method for obtaining high-resolution images using different lighting modes, characterized in that, include: At least a negative photosensitive film layer, a positive photosensitive film layer, and a metal reinforcement layer are formed sequentially on a substrate, wherein the negative photosensitive film layer is close to the substrate; The material of the metal reinforcement layer includes a material for exciting surface plasma; The first illumination mode is used to expose the positive photosensitive film layer based on a mask, and the second illumination mode is used to expose the negative photosensitive film layer based on the same mask. The first illumination mode includes positive incident illumination, and the second illumination mode includes off-axis illumination. The illumination wavelengths of the first and second illumination modes are the same, and the first depth of focus of the first illumination mode is less than the second depth of focus of the second illumination mode. The illumination wavelengths of the first and second illumination modes include one of 365 nm, 248 nm, 193 nm, and 13.5 nm. The mask pattern height of the mask is 30 nm to 50 nm, the period of the mask pattern is 40 nm to 300 nm, the duty cycle of the mask pattern is 3:1 to 1:1, and the critical dimension of the mask pattern is 20 nm to 150 nm. The exposure dose of the normal incident illumination is 20 mJ / cm². 2 -200 mJ / cm 2 The slit width of the patterned structure on the positive photosensitive film layer is greater than half the period of the mask pattern; The off-axis illumination has an illumination angle of 5° to 90° and an exposure dose of 50 mJ / cm². 2 -300 mJ / cm 2 The linewidth of the pattern structure on the negative photosensitive film layer is less than half the period of the mask pattern, and the pattern structure on the negative photosensitive film layer is opposite to the structure of the mask pattern of the mask plate. The positively sensing film layer and the negatively sensing film layer after exposure are developed sequentially to obtain the pattern structure produced by the two exposures. The graphic structure generated by the two exposures is transferred to the substrate to obtain a high-resolution graphic.

2. The method according to claim 1, characterized in that, The negative photosensitive film layer and the positive photosensitive film layer are prepared by coating, spraying, or fumigation. The material of the positive photosensitive film layer includes at least one of AR series photoresist, AZ series photoresist, and PHS photoresist; The thickness of the positive photosensitive film layer is 20 nm to 50 nm; The material of the negative photosensitive film layer includes at least one of SU-8 photoresist and polyester photoresist, and the thickness of the negative photosensitive film layer is 50 nm to 1000 nm.

3. The method according to claim 1, characterized in that, The metal reinforcement layer is prepared by methods such as thermal evaporation, electron beam evaporation, magnetron sputtering deposition, chemical vapor deposition, or coating.

4. The method according to claim 1, characterized in that, The light-blocking layer material of the mask includes at least one of chromium, silicon, and molybdenum.

5. The method according to claim 1, characterized in that, The sequential development of the exposed positive photosensitive film layer and the exposed negative photosensitive film layer includes: The positive photosensitive film layer is developed using a positive developer, wherein the positive developer includes at least one of TMAH developer and NaOH developer; The negative photosensitive film layer is developed using a negative developer, wherein the negative developer includes at least one of butyl acetate developer, ethyl 3-ethoxypropionate developer, and 2-heptanone developer.

6. The method according to claim 1, characterized in that, The step of transferring the pattern structure generated by the two exposures to the substrate includes: The pattern structure generated by two exposures is transferred to the substrate using ion beam etching, reactive ion etching, or inductively coupled plasma etching.

7. The method according to claim 1, characterized in that, The substrate may be a transparent substrate or an opaque substrate; The transparent substrate includes a glass substrate or a sapphire substrate; The opaque substrate includes a silicon substrate.

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