Machining device and method for increasing electric conduction area through laser interference photoetching

Abstract

The invention discloses a processing device and method for increasing an electric conduction area through laser interference photoetching, and belongs to the technical field of laser interference photoetching. A processing device for increasing an electric conduction area through laser interference photoetching comprises a laser light source, a diaphragm is fixed behind the laser light source, a shutter is fixed behind the diaphragm, a diffraction beam splitter is fixed behind the shutter, a collimating prism is fixed behind the diffraction beam splitter, and the collimating prism is fixed behind the laser light source. A first linear polaroid, a second linear polaroid, a third linear polaroid and a fourth linear polaroid are respectively fixed behind the collimating prism; and the first linear polaroid, the second linear polaroid, the third linear polaroid and the fourth linear polaroid are positioned on the same plane and are arranged in a circumferential array. The prismatic micro-nano structure array is prepared on the surface of the conductive material, so that the specific surface area of the material is increased, the transmission density of current in the material is increased, the conduction resistance of the material is reduced, and the conductive efficiency of the material is finally improved.

Description

Technical Field

[0001] This invention relates to the field of laser interference lithography technology, specifically to a processing apparatus and method for increasing the electrical conductivity area using laser interference lithography. Background Technology

[0002] Laser interference lithography is a micro-nano fabrication technology that has attracted much attention in recent years. Its basic principle is to use the interference effect of two or more coherent beams of light to form a periodic light intensity distribution on the surface of a material, thereby obtaining micro-nano-scale periodic structures on photosensitive materials through processes such as exposure and development. This technology can achieve large-area, high-resolution patterned structures in a single exposure, without the need for expensive masks, and has advantages such as simple process, low cost, and high resolution.

[0003] Currently, laser interference lithography is widely used in semiconductor manufacturing, photonic devices, and biomedical microstructure fabrication to prepare various functional devices such as microfluidic chips, optical filters, and biosensors. By adjusting parameters such as laser wavelength, incident angle, polarization state, and beam phase, the period and morphology of the structure can be flexibly controlled, enabling the controllable fabrication of two-dimensional and even three-dimensional micro / nano structures. This technology, with its high precision, flexibility, and scalability, occupies an important position in the field of micro / nano fabrication.

[0004] However, in existing laser interference lithography applications, research has primarily focused on the precise control of pattern resolution and structural morphology, with less attention paid to how to effectively improve the electrical conductivity of materials using interference lithography structures. Current conductive materials typically rely on chemical etching, electroplating, and template replication to increase surface area, but these methods generally suffer from complex fabrication processes, poor structural uniformity, insufficient controllability, and limited adaptability to substrate materials. This results in low efficiency and poor stability in improving conductivity, making it difficult to achieve large-area, highly consistent conductive structure fabrication. Therefore, current technology lacks a solution that can efficiently fabricate controllable periodic micro / nano structures directly on conductive materials or their substrates using laser interference lithography, thereby significantly increasing the electrical conductivity area and improving conductivity efficiency.

[0005] Therefore, we propose a processing device and method for increasing the electrical conductivity area using laser interference lithography to solve the above problems. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a processing apparatus and method for increasing the electrical conductivity area using laser interference lithography, thus solving the problems mentioned in the background section.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0010] A processing apparatus for increasing the electrical conductivity area using laser interference lithography includes a laser source, an aperture fixed after the laser source, a shutter fixed after the aperture, a diffraction beam splitter fixed after the shutter, a collimating prism fixed after the diffraction beam splitter, and a first linear polarizer, a second linear polarizer, a third linear polarizer, and a fourth linear polarizer fixed after the collimating prism, respectively. The first, second, third, and fourth linear polarizers are in the same plane and arranged in a circular array. A first continuous neutral density filter is fixed after the first linear polarizer, and a second continuous neutral density filter is fixed after the second linear polarizer. A continuous neutral density filter is provided, wherein a third continuous neutral density filter is fixed after the third linear polarizer, and a fourth continuous neutral density filter is fixed after the fourth linear polarizer. The first, second, third, and fourth continuous neutral density filters are arranged in a circular array on the same plane. An aspherical condenser lens is fixed after the first, second, third, and fourth continuous neutral density filters, and a sample stage is fixed after the aspherical condenser lens.

[0011] Furthermore, the laser source is a 1064nm wavelength continuous-wave high-power laser.

[0012] Furthermore, the diffraction beam splitter is a two-dimensional Damman grating fused silica optical glass lens with periodic cuboid micro-protrusions on its surface; the lens is flat and cylindrical, with a circular bottom surface of 8 mm in diameter and a thickness of 1 mm; the diffraction angle of the ±1st order diffracted light of the lens is 7.5°; the cuboid micro-protrusions on the two diagonals of the lens surface form a minimum diffraction unit with a period of 8.15 μm; the length and width of the rectangular cuboid micro-protrusions on the lens surface are both 4.075 μm.

[0013] Furthermore, the collimating prism is a pyramid-shaped fused silica optical glass lens; the bottom surface of the lens is a square with a side length of 40mm, and the bottom surface of the lens is coated with a 1064nm wavelength anti-reflection coating; the side surface of the lens is four congruent isosceles triangles, with a side length of 28.86mm, a height of 20.80mm, a vertex angle of 87.74°, and a base angle of 46.13°, and the side surface of the lens is coated with a 1064nm wavelength anti-reflection coating, and the angle between the side surface of the lens and the bottom surface of the lens is 15.95°.

[0014] A processing method for a laser interference lithography apparatus for increasing the electrically conductive area includes the following steps:

[0015] Step 1: Fix the conductive material on the surface of the sample stage, and adjust the distance between the sample stage and the aspherical condenser lens so that the focal point coincides with the surface of the conductive material.

[0016] Step 2: By adjusting the opening and closing degree of the aperture blades, control the exposure area when the diffracted beam converges on the surface of the conductive material;

[0017] Step 3: Control the interference angle when the diffracted beam converges on the surface of the conductive material by adjusting the distance between the collimating prism and the diffraction beam splitter;

[0018] Step 4: By rotating the first, second, third, and fourth linear polarizers, the angle between the transmission axis of the first, second, third, and fourth linear polarizers and the incident plane of the diffracted light is 90°. Then, rotate the first, second, third, and fourth continuous neutral density filters to make the power of the four diffracted beams the same. This will make the spatial interference light field intensity distributed in a prismatic array when the diffracted light converges on the surface of the conductive material.

[0019] Step 5: By adjusting the duration of the shutter opening and closing states, the interference exposure dose when the diffracted beam converges on the surface of the conductive material is controlled, thereby controlling the depth of the prismatic columnar array structure formed within the conductive material.

[0020] (III) Beneficial Effects

[0021] Compared with the prior art, the present invention provides a processing apparatus and method for increasing the electrical conductivity area by laser interference lithography, which has the following beneficial effects:

[0022] This invention uses a diffraction beam splitter to split the beam and an aspherical focusing lens to combine the beams for device construction, which is simpler in system structure than using a planar beam splitter / combiner. By changing the position of the prism on the optical axis of the system, the interference angle of the focused light on the conductive material can be adjusted, which is more convenient than using a mirror group or other methods to adjust the size of the interference angle.

[0023] By using a linear polarizer to adjust the beam polarization angle of the diffracted light emitted from the diffraction beam splitter and by using a continuous neutral density filter to adjust the beam power of the aligned light, the beam parameters of the device described above are more adjustable. The method of using laser interference lithography to form interference patterns on the surface of a conductive sample to increase the conductive area is more economical and convenient than other methods of preparing patterns on the surface of conductive materials to increase the conductive area. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the diffraction beam splitter of the present invention;

[0026] Figure 3 This is a top view of the collimating prism of the present invention.

[0027] Figure 4 This is a side view of the collimating prism of the present invention.

[0028] Figure 5 This is a schematic diagram of the isometric structure of the collimating prism of the present invention;

[0029] Figure 6 This is an electron microscope image of the stripe structure prepared on the surface of a copper sheet by the two-beam interference method of the present invention;

[0030] Figure 7 This is a top view schematic diagram of the fringe structure formed by direct interference writing on the surface of a conductive material using the dual-beam interference method of the present invention;

[0031] Figure 8 This is a schematic diagram of the central cross-section of the fringe structure formed by direct writing of interference on the surface of a conductive material using the two-beam interference method of the present invention;

[0032] Figure 9 This is an electron microscope image of the rhombic structure prepared on the surface of a copper sheet by four-beam interference according to the present invention;

[0033] Figure 10 This is a top view schematic diagram of the prism array structure formed by direct interference writing on the surface of a conductive material using four-beam interference according to the present invention;

[0034] Figure 11 This is a schematic diagram of the central cross-section of the prism array structure formed by direct writing of the four-beam interference on the surface of a conductive material according to the present invention.

[0035] In the diagram: 1. Laser source; 2. Aperture; 3. Shutter; 4. Diffraction beam splitter; 5. Collimating prism; 6. First linear polarizer; 7. Second linear polarizer; 8. Third linear polarizer; 9. Fourth linear polarizer; 10. First continuous neutral density filter; 11. Second continuous neutral density filter; 12. Third continuous neutral density filter; 13. Fourth continuous neutral density filter; 14. Aspherical condenser lens; 15. Sample stage. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] like Figure 1 As shown in the figure, an embodiment of the present invention provides a processing apparatus for increasing the electrical conductivity area using laser interference lithography, comprising a laser source 1, which is a 1064nm wavelength continuous-type high-power laser; an aperture 2 is fixed after the laser source 1; a shutter 3 is fixed after the aperture 2; a diffraction beam splitter 4 is fixed after the shutter 3; a collimating prism 5 is fixed after the diffraction beam splitter 4; and a first linear polarizer 6, a second linear polarizer 7, a third linear polarizer 8, and a fourth linear polarizer 9 are fixed after the collimating prism 5, respectively. The first linear polarizer 6, the second linear polarizer 7, the third linear polarizer 8, and the fourth linear polarizer 9 are located in the same plane and arranged in a circular array. A first continuous-type neutral density filter 10 is fixed after the first linear polarizer 6; the second linear polarizer 7, the third linear polarizer 8, and the fourth linear polarizer 9 are fixed after the first linear polarizer 6; and a first continuous-type neutral density filter 10 is fixed after the first linear polarizer 6. A second continuous neutral density filter 11 is fixed after polarizer 7, a third continuous neutral density filter 12 is fixed after the third linear polarizer 8, and a fourth continuous neutral density filter 13 is fixed after the fourth linear polarizer 9. The first continuous neutral density filter 10, the second continuous neutral density filter 11, the third continuous neutral density filter 12, and the fourth continuous neutral density filter 13 are arranged in a circular array on the same plane. An aspherical condenser lens 14 is fixed after the first continuous neutral density filter 10, the second continuous neutral density filter 11, the third continuous neutral density filter 12, and the fourth continuous neutral density filter 13. A sample stage 15 is fixed after the aspherical condenser lens 14.

[0039] Laser source 1 is fixed at the front end of the optical platform. When laser source 1 is turned on, the laser beam passes through the center of the aperture 2 through the aperture 2 blade perpendicularly. When shutter 3 is turned on, the beam passes through shutter 3 and enters the interference exposure system. When shutter 3 is turned off, the beam is blocked by shutter 3. When the laser beam enters the diffraction beam splitter 4, it is diffracted into two pairs of ±1st order diffraction beams with mutually orthogonal output surfaces. The +1st order diffraction beam A and the -1st order diffraction beam B are coplanar.

[0040] +1st order diffracted light A beam path: +1st order diffracted light A is incident on the side of collimating prism 5 at an angle of 7.5° with the optical axis. After being refracted by collimating prism 5, it exits the lower surface of collimating prism 5 parallel to the optical axis. The beam energy of +1st order diffracted light A can be adjusted by the first continuous neutral density filter 10. After being refracted by aspherical condenser lens 14, the propagation direction of +1st order diffracted light A is deflected towards the focal point of aspherical condenser lens 14.

[0041] +1st order diffracted light B beam path: +1st order diffracted light B is incident on the side of collimating prism 5 at an angle of 7.5° with the optical axis. After being refracted by collimating prism 5, it exits the lower surface of collimating prism 5 parallel to the optical axis. The beam energy of +1st order diffracted light B can be adjusted by the second continuous neutral density filter 11. After being refracted by aspherical condenser lens 14, the propagation direction of +1st order diffracted light B is deflected towards the focal point of aspherical condenser lens 14.

[0042] -1st order diffracted light A beam path: -1st order diffracted light A is incident on the side of collimating prism 5 at an angle of 7.5° with the optical axis. After being refracted by collimating prism 5, it exits the lower surface of collimating prism 5 parallel to the optical axis. The beam energy of -1st order diffracted light A can be adjusted by the third continuous type neutral density filter 12. After being refracted by aspherical condenser lens 14, the propagation direction of -1st order diffracted light A is deflected towards the focal point of aspherical condenser lens 14.

[0043] -1st order diffracted light B beam path: -1st order diffracted light B is incident on the side of collimating prism 5 at an angle of 7.5° with the optical axis. After being refracted by collimating prism 5, it exits the lower surface of collimating prism 5 parallel to the optical axis. The beam energy of -1st order diffracted light B can be adjusted by the fourth continuous type neutral density filter 13. After being refracted by aspherical condenser lens 14, the propagation direction of -1st order diffracted light B is deflected towards the focal point of aspherical condenser lens 14.

[0044] The +1st order diffraction beam A, -1st order diffraction beam A, +1st order diffraction beam B, and -1st order diffraction beam B are refracted by the aspherical focusing lens 14 and converge on the conductive sample surface on the sample stage 15.

[0045] like Figure 2 As shown, the diffraction beam splitter 4 is a two-dimensional Damman grating fused silica optical glass lens with periodic cuboid micro-protrusions on its surface. The lens is flat and cylindrical, with a circular bottom surface of 8 mm in diameter and a thickness of 1 mm. The diffraction angle of the ±1st order diffracted light is 7.5°. The cuboid micro-protrusions on the two diagonals of the lens surface form a minimum diffraction unit with a period of 8.15 μm. The length and width of the rectangular cuboid micro-protrusions on the lens surface are both 4.075 μm. After a single laser beam is incident on the diffraction beam splitter, a 2×2 light spot array with the same spacing can be observed on a spatial cross-section parallel to the diffraction beam splitter 4.

[0046] like Figure 3 , Figure 4 , Figure 5As shown, the collimating prism 5 is a pyramid-shaped fused silica optical glass lens; the bottom surface of the lens is a square with a side length of 40mm, coated with a 1064nm wavelength anti-reflection coating; the side surface of the lens consists of four congruent isosceles triangles with a side length of 28.86mm, a height of 20.80mm, a vertex angle of 87.74°, and a base angle of 46.13°. The side surface of the lens is coated with a 1064nm wavelength anti-reflection coating, and the angle between the side surface and the bottom surface of the lens is 15.95°. When a beam of light with an angle of 7.5° to the optical axis of the system is incident on the side surface of the collimating prism 5, the incident light after refraction will exit at a 90° angle to the bottom surface of the collimating prism 5.

[0047] A processing method for a laser interference lithography apparatus for increasing the electrically conductive area includes the following steps:

[0048] Step 1: Fix the conductive material on the surface of the sample stage 15, and adjust the distance between the sample stage 15 and the aspherical condenser lens 14 so that the focal point coincides with the surface of the conductive material.

[0049] Step 2: By adjusting the opening and closing degree of the aperture 2 blades, the exposure area when the diffracted beam converges on the surface of the conductive material is controlled;

[0050] Step 3: By adjusting the distance between the collimating prism 5 and the diffraction beam splitter 4, the interference angle when the diffracted beam converges on the surface of the conductive material is controlled;

[0051] Step 4: By rotating the first linear polarizer 6, the second linear polarizer 7, the third linear polarizer 8, and the fourth linear polarizer 9, the angle between the transmission axis of the first linear polarizer 6, the second linear polarizer 7, the third linear polarizer 8, and the fourth linear polarizer 9 and the incident plane of the diffracted light is 90°. Then, rotate the first continuous neutral density filter 10, the second continuous neutral density filter 11, the third continuous neutral density filter 12, and the fourth continuous neutral density filter 13 to make the power of the four diffracted beams the same. This will make the intensity of the spatial interference light field formed when the diffracted light converges on the surface of the conductive material present as a prismatic array.

[0052] Step 5: By adjusting the duration of shutter 3's open and closed states, the interference exposure dose when the diffracted beam converges on the surface of the conductive material is controlled, thereby controlling the depth of the prismatic columnar array structure formed within the conductive material.

[0053] like Figure 6This is an electron microscope image of a striped structure fabricated on a copper sheet surface using a laser interference lithography (LAC) device to increase the electrical conductivity area. A laser source 1 emits Gaussian monochromatic light, which is split into four diffracted beams by a diffractor beam splitter 4. The diffracted beams are refracted by the inclined plane of a collimating prism 5 into two parallel collimated beams. A first linear polarizer 6, a second linear polarizer 7, a third linear polarizer 8, and a fourth linear polarizer 9 are used to adjust the polarization state of the collimated beams. A first continuous neutral density filter 10, a second continuous neutral density filter 11, a third continuous neutral density filter 12, and a fourth continuous neutral density filter 13 are used to adjust the beam energy of the collimated beams. Finally, the collimated beams are converged by an aspherical condenser lens 14 at a point on the copper sheet surface on the sample stage 15, where interference occurs. An aperture 2 is used for beam shaping and filtering out poorly positioned beam edges. A shutter 3 is used to control the interference exposure time. In this embodiment, an opaque baffle is used to block the light passing through the first linear polarizer 6 and the third linear polarizer 8. The transmission axes of the second linear polarizer 7 and the fourth linear polarizer 9 are adjusted to be parallel to each other and perpendicular to their respective diffraction light emission planes. Under the conditions of a laser energy of 200mW, adjusting the first continuous neutral density filter 10 and the third continuous neutral density filter 12 to reduce the single beam energy to 30mW, and an exposure time of 12s, a stripe structure with a period of 2.6μm is obtained on the surface of the copper sheet. Compared with the untreated copper sheet, the sample after interference has a larger specific surface area and better conductivity.

[0054] like Figure 7 and Figure 8 As shown in the figure, the fringe structure formed by direct writing of interference on the surface of a conductive material by dual-beam interference provided in this embodiment of the invention is a schematic diagram. The internal structure of the circular exposure area is a prismatic array, and the specific surface area is larger than that of the unexposed area.

[0055] Example 2:

[0056] like Figure 9This is an electron microscope image of a rhombic structure fabricated on a copper sheet surface using a laser interference lithography (LAC) device to increase the electrical conductivity area. A laser source 1 emits Gaussian monochromatic light, which is split into four diffracted beams by a diffractor beam splitter 4. The diffracted beams are refracted by the inclined plane of a collimating prism 5 into two parallel collimated beams. A first linear polarizer 6, a second linear polarizer 7, a third linear polarizer 8, and a fourth linear polarizer 9 are used to adjust the polarization state of the collimated beams. A first continuous neutral density filter 10, a second continuous neutral density filter 11, a third continuous neutral density filter 12, and a fourth continuous neutral density filter 13 are used to adjust the beam energy of the collimated beams. Finally, the collimated beams are converged by an aspherical condenser lens 14 at a point on the copper sheet surface on the sample stage 15, where interference occurs. An aperture 2 is used for beam shaping and filtering out poorly quality beam edges. A shutter 3 is used to control the interference exposure time. In this embodiment, the transmission axes of the first linear polarizer 6 and the third linear polarizer 8, and the second linear polarizer 7 and the fourth linear polarizer 9 are adjusted to be perpendicular to their respective diffraction light output planes. Under the conditions of a laser energy of 200mW, adjusting the first continuous neutral density filter 10, the second continuous neutral density filter 11, the third continuous neutral density filter 12, and the fourth continuous neutral density filter 13 to reduce the single beam energy to 34mW, and an exposure time of 9s, a rhomboid structure with a period of 3.3μm is obtained on the surface of a copper sheet. Compared with an untreated copper sheet, the sample after interference has a larger specific surface area and better conductivity.

[0057] like Figure 10 and Figure 11 As shown in the figure, the prism array structure formed by four-beam interference direct writing on the surface of a conductive material provided in this embodiment of the invention has a prism array structure inside the circular exposure area, and the specific surface area is larger than that of the unexposed area.

[0058] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A processing apparatus for increasing the electrical conductivity area using laser interference lithography, comprising a laser source (1), characterized in that: An aperture stop (2) is fixed after the laser source (1), a shutter (3) is fixed after the aperture stop (2), a diffraction beam splitter (4) is fixed after the shutter (3), a collimating prism (5) is fixed after the diffraction beam splitter (4), and a first linear polarizer (6), a second linear polarizer (7), a third linear polarizer (8), and a fourth linear polarizer (9) are fixed after the collimating prism (5). The first linear polarizer (6), the second linear polarizer (7), the third linear polarizer (8), and the fourth linear polarizer (9) are in the same plane and arranged in a circular array. A first continuous neutral density filter (10) is fixed after the first linear polarizer (6), and a second continuous neutral density filter (11) is fixed after the second linear polarizer (7). A third continuous neutral density filter (12) is fixed after the third linear polarizer (8), and a fourth continuous neutral density filter (13) is fixed after the fourth linear polarizer (9). The first continuous neutral density filter (10), the second continuous neutral density filter (11), the third continuous neutral density filter (12), and the fourth continuous neutral density filter (13) are in the same plane and arranged in a circular array. An aspherical condenser lens (14) is fixed after the first continuous neutral density filter (10), the second continuous neutral density filter (11), the third continuous neutral density filter (12), and the fourth continuous neutral density filter (13). A sample stage (15) is fixed after the aspherical condenser lens (14).

2. The processing apparatus for increasing the electrical conductivity area by laser interference lithography according to claim 1, characterized in that: The laser source (1) is a 1064nm wavelength continuous high-power laser.

3. The processing apparatus for increasing the electrical conductivity area by laser interference lithography according to claim 1, characterized in that: The diffraction beam splitter (4) is a two-dimensional Damman grating fused silica optical glass lens with periodic cuboid micro-protrusions on its surface; the lens is flat and cylindrical, with a circular bottom surface of 8 mm in diameter and a thickness of 1 mm; the diffraction angle of the ±1st order diffracted light of the lens is 7.5°; the cuboid micro-protrusions on the two diagonals of the lens surface form a minimum diffraction unit with a period of 8.15 μm; the length and width of the rectangular cuboid micro-protrusions on the lens surface are both 4.075 μm.

4. The processing apparatus for increasing the electrical conductivity area by laser interference lithography according to claim 1, characterized in that: The collimating prism (5) is a pyramid-shaped fused silica optical glass lens; the bottom surface of the lens is a square with a side length of 40mm, and the bottom surface of the lens is coated with a 1064nm wavelength anti-reflection coating; the side surface of the lens is four congruent isosceles triangles with a side length of 28.86mm, a height of 20.80mm, a vertex angle of 87.74°, and a base angle of 46.13°. The side surface of the lens is coated with a 1064nm wavelength anti-reflection coating, and the angle between the side surface of the lens and the bottom surface of the lens is 15.95°.

5. The processing method of the laser interference lithography processing apparatus for increasing the electrical conductivity area according to any one of claims 1-4, characterized in that: Includes the following steps: Step 1: Fix the conductive material on the surface of the sample stage (15), and adjust the distance between the sample stage (15) and the aspherical condenser lens (14) so ​​that the focal point coincides with the surface of the conductive material. Step 2: By adjusting the opening and closing degree of the aperture (2) blades, control the exposure area when the diffracted beam converges on the surface of the conductive material; Step 3: By adjusting the distance between the collimating prism (5) and the diffraction beam splitter (4), the interference angle when the diffracted beam converges on the surface of the conductive material is controlled; Step 4: By rotating the first linear polarizer (6), the second linear polarizer (7), the third linear polarizer (8), and the fourth linear polarizer (9), the angle between the transmission axis of the first linear polarizer (6), the second linear polarizer (7), the third linear polarizer (8), and the fourth linear polarizer (9) and the incident plane of the diffracted light is 90°. Then, rotate the first continuous neutral density filter (10), the second continuous neutral density filter (11), the third continuous neutral density filter (12), and the fourth continuous neutral density filter (13) to make the power of the four diffracted beams the same. This will make the intensity of the spatial interference light field formed when the diffracted light converges on the surface of the conductive material appear as a prismatic array. Step 5: By adjusting the duration of the shutter (3) opening and closing states, the interference exposure dose when the diffracted beam converges on the surface of the conductive material is controlled, thereby controlling the depth of the prismatic columnar array structure formed in the conductive material.

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