Periodic three-dimensional micro-nano structure multi-beam laser interference lithography system and method

Abstract

This invention discloses a multi-beam laser interference lithography system and method for periodic three-dimensional micro / nano structures. The system includes a laser, a diffraction element, a 4F collimation-beam control-focusing module, and a piezoelectric stick-slip precision motion system. The laser is perpendicularly incident on the diffraction element, which diffracts the beam into N sub-beams and one central beam distributed symmetrically. The 4F collimation-beam control-focusing module includes a first Fourier transform lens, a custom beam control frame, and a second inverse Fourier transform lens. The first Fourier transform lens collimates the umbrella-shaped N+1 beam generated by the diffraction element into a parallel N+1 beam. The custom beam control frame includes a half-wave plate and a polarizer along the optical axis. The second inverse Fourier transform lens focuses the parallel N+1 beams onto the same point on the sample. The lithography of the sample is completed by coordinating the spatial interference light field with the movement of the piezoelectric stick-slip precision motion system.

Description

Technical Field

[0001] This invention relates to the field of micro-nano manufacturing, and more specifically, to a multi-beam laser interference lithography system and method for periodic three-dimensional micro-nano structures. Background Technology

[0002] With the rapid development of optical communication and information technology, semiconductors and microelectronics, and biomedical and health engineering, the demand for manufacturing complex three-dimensional spatially periodically distributed micro / nano structures (such as three-dimensional photonic crystals, metamaterials, and microlens arrays) with high precision, high controllability, and large area is growing rapidly. These periodic three-dimensional micro / nano structures can form complete photonic band gaps within themselves, allowing for arbitrary control of the amplitude, phase, and polarization of incident electromagnetic waves across all dimensions, forming the core foundation for next-generation high-performance optical devices. Simultaneously, the periodic arrangement of functional micro / nano materials endows these structures with extremely high specific surface area, excellent mechanical properties (such as ultra-lightweight, ultra-high specific strength, and negative Poisson's ratio), novel electrical and thermal properties (such as high electron mobility, tunable electronic band structure, and phonon band gap control), and unique surface physicochemical wettability. This makes them irreplaceable in a wide range of fields, including microelectromechanical systems (MEMS), flexible electronic sensing, high-efficiency catalysis, and intelligent new materials.

[0003] In existing micro / nano fabrication technologies, traditional high-resolution projection lithography, such as extreme ultraviolet (EUV) and deep ultraviolet (DUV) lithography, while achieving significant breakthroughs in miniaturizing two-dimensional planar feature sizes, is limited by the extremely shallow depth of field of the optical system, the uniformity of structural forms, and the deep dependence on expensive masks. This makes it difficult to directly construct complex three-dimensional structures with large aspect ratios through a single exposure. Multi-beam interference lithography, as a typical maskless advanced manufacturing technology, utilizes the linear superposition of multiple coherent light waves in space to directly excite a standing wave light field with a three-dimensional periodic distribution within the photosensitive medium, thereby achieving efficient fabrication of large-area periodic three-dimensional micro / nano structures. However, as this technology advances towards the fabrication of centimeter-scale macroscopic and diverse controllable patterned micro / nano structures, it still faces the following three core scientific and engineering challenges:

[0004] First, there are challenges in achieving high aspect ratios and system integration. Traditional ultraviolet light sources have weak penetration capabilities, and the thickness of the fabricated micro / nano structures is typically a few micrometers or less. This results in periodic three-dimensional micro / nano structures with fewer layers or greater overall fragility. Furthermore, traditional ultraviolet light sources are expensive and invisible to the naked eye. The alignment processes, such as optical path reflection, beam expansion and collimation, and spatial filtering, require the use of fluorescent cards, significantly increasing the difficulty of constructing complex interference optical paths and the likelihood of adjustment errors.

[0005] Second, the spatial redundancy and phase instability of the beam splitting mechanism. Traditional MBIL (Multi-Beam Laser Interference Lithography) systems rely heavily on amplitude splitting principles. The cascaded semi-transparent and semi-reflective prism matrix results in an extremely long optical path structure and significant optical path differences between sub-beams. This non-common optical path characteristic makes the system extremely sensitive to fluctuations in ambient temperature gradients, air turbulence, and low-frequency mechanical micro-vibrations, easily inducing random phase drift, which in turn leads to attenuation of interference pattern contrast and pattern distortion. Furthermore, the lattice morphology of the interference optical field is highly dependent on the precise configuration of the amplitude, polarization vector, phase, and optical power of each sub-beam. In existing amplitude-splitting optical paths, independently modulating the three-dimensional parameters of up to N+1 (N not less than 3, typically 4) coherent beams would greatly increase the number of system components, cost, and accumulated optical path errors, and is difficult to achieve in a compact space, limiting the compactness and integration of periodic three-dimensional micro / nano structure manufacturing systems.

[0006] Third, the fabrication area of ​​multi-beam laser interference lithography is limited by the single-exposure fabrication area. Constrained by the Gaussian beam waist distribution and the effective field of view per exposure, the fabrication area of ​​periodic micro / nano structures in a single exposure is limited, and there are significant differences between the structures at the edge and center of the field of view. Therefore, large-area structure fabrication must be achieved through matrix-style exposure stitching with a precision motion system that repeats step-stationary-exposure cycles. However, traditional large-stroke precision motors cannot simultaneously possess extreme performance characteristics such as centimeter-level stroke, nanometer-level precision, zero thermal drift static self-locking, extremely high rigidity and compactness, and vacuum compatibility. High-precision motor systems with a coarse-fine combination often have complex structures and controls, high costs, and are difficult to maintain.

[0007] Fourth, the challenge of introducing controllable defects based on multi-beam laser interference lithography. In existing technologies, the periodic three-dimensional micro-nano structures fabricated by a single exposure have a consistent structure across the entire field of view. For photonic devices that require the introduction of locally controllable defects, existing technologies are still insufficient to meet application needs.

[0008] In summary, there is an urgent need for a precision motion platform that can solve the beam splitting and modulation problems from the source of optical architecture, and provide a platform that combines large stroke, nanometer-level precision, zero thermal drift static self-locking and high structural compactness, so as to realize the high-quality splicing and manufacturing of large-area periodic three-dimensional micro-nano structures. Summary of the Invention

[0009] This invention provides a multi-beam laser interference lithography system for large-area periodic three-dimensional micro / nano structures to address the technical problems existing in the prior art. The system employs a 532... A nm green single-mode continuous laser can simultaneously meet the requirements of high coherence length, high penetration, low power jitter, visualization, and low cost. By using diffractive optical elements (DOEs), the wavefront of a single incident Gaussian beam is spatially modulated and diffracted into N sub-beams and one central beam with central symmetry, ensuring consistent optical path length and constant phase difference among the N sub-beams, thus improving optical path compactness and anti-interference capability. The 4F collimation-beam control-focusing module includes a first Fourier transform lens coaxially arranged along the optical axis, a custom beam control frame located on the Fourier spectrum plane, and a second inverse Fourier transform lens, which can achieve collimation and focusing of multiple beams in a small optical path and compact space, and independently control the polarization angle and optical power of a single beam. The piezoelectric stick-slip precision motion system has the advantages of centimeter-level stroke, nanometer-level precision, static self-locking with zero thermal drift, extremely high rigidity and compactness, vacuum compatibility, and simple control.

[0010] Specifically, this application provides a multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures, the system comprising a laser, a diffraction element, a 4F collimation-beam control-focusing module, and a piezoelectric stick-slip precision motion system;

[0011] The laser emits a single Gaussian beam that is perpendicularly incident on a diffraction element. The diffraction element modulates and diffracts the wavefront of the single perpendicularly incident Gaussian beam in space into N sub-beams and 1 central beam that are centrally symmetrically distributed, forming an umbrella-shaped N+1 beam configuration, wherein N is not less than 3.

[0012] The 4F collimation-beam control-focusing module includes a first Fourier transform lens, a custom beam control frame, and a second inverse Fourier transform lens arranged coaxially along the optical axis. The first Fourier transform lens collimates the umbrella-shaped N+1 beam generated by the diffraction element into a parallel N+1 beam. The custom beam control frame includes two sets of lenses along the optical axis: a first set of half-wave plates and a second set of polarizers. The polarization angle of the beam is independently controlled by rotating the polarizers, and the beam power is adjusted by rotating the half-wave plates. The second inverse Fourier transform lens focuses the parallel N+1 beam onto the same point on the sample. The sample is mounted on a piezoelectric stick-slip precision motion system. The photolithography of the sample is completed by spatial interference combined with the movement of the piezoelectric stick-slip precision motion system.

[0013] The piezoelectric stick-slip precision motion system includes three series-connected single-degree-of-freedom piezoelectric stick-slip actuators. The sample is mounted at the end of the Z-axis piezoelectric stick-slip actuator, and the piezoelectric stick-slip precision motion system is used to realize the three-dimensional spatial motion of the sample.

[0014] Furthermore, the laser is a green single-mode continuous laser.

[0015] Furthermore, the system also includes at least one reflector, which is installed between the laser emitting end and the diffraction element incident end. The reflector reflects the laser emitted by the laser, so that the laser beam is perpendicular to the diffraction element and coincides with the center of the diffraction element.

[0016] Furthermore, the spacing between the first Fourier transform lens, the customized beam control frame, and the second inverse Fourier transform lens of the 4F collimation-beam control-focusing module is adjustable, so that the positional relationship of the 4F collimation-beam control-focusing module meets the requirements of the 4F principle.

[0017] The method for photolithography using the aforementioned multi-beam laser interference lithography system with periodic three-dimensional micro / nano structures includes the following steps:

[0018] S1. Determine the target thickness for manufacturing periodic three-dimensional micro / nano structures. Discretize the target thickness of the material to be processed in three-dimensional space as a multi-layer processing plane distributed along the z-direction, and calculate the discrete thickness d3 of a single layer in the z-direction.

[0019] S2. Perform z-axis first layer x-axis exposure; when exposing z-axis first layer x-axis first row first point, the piezoelectric stick-slip precision motion system remains stationary, the control laser signal is turned on, the interference light field resides inside the photosensitive material for exposure, after the exposure is completed, the control laser signal is turned off, and then the piezoelectric stick-slip precision motion system is driven to move a specific distance d1 along the positive x-axis to the second point, and the z-axis first layer x-axis second point is exposed, and so on to complete the single row full point exposure of x-axis first row;

[0020] S3, drive the piezoelectric stick-slip precision motion system to step a distance d2 in the y direction to the negative starting coordinate of the second row in the x direction, complete the point exposure of the second row along the -x direction, repeat in sequence until the full-domain matrix exposure of the first layer of two-dimensional plane in the z direction is completed;

[0021] S4. Remove the sample, add a single layer of material with discrete thickness in the z-direction to the surface of the current sample, and install it back in place; repeat steps S2 and S3 to complete the global matrix exposure of the second two-dimensional plane in the z-direction; repeat this process until the layer-by-layer additive manufacturing and full exposure of the material to be processed are completed.

[0022] Furthermore, the method for determining the z-axis single-layer discrete thickness d3 is as follows:

[0023] First, construct the spatial Gaussian envelope interference light field distribution function I of the umbrella-shaped N+1 beam. total (r):

[0024] ;

[0025] In the formula, w0 is the waist radius of the Gaussian beam, w(z) is the characteristic radius that varies with depth, I0 is the central peak intensity, r is the three-dimensional spatial coordinate vector, i and j are the sub-beam indices participating in the interference, and A i With A j e represents the electric field amplitude corresponding to the sub-beam. i With e j To determine the electric field polarization direction vector for the interference polarization condition, k i With k j Let φ be the spatial wave vector. i With φ j Let x, y, and z be the initial phase, and let r be the three-dimensional coordinates of the spatial coordinate r.

[0026] Because the dynamic absorption coefficient α of the photoresist decreases with the consumption of local acid-generating agents, the effective photochemical cumulative dose at the interface of adjacent exposure layers reaches the critical polymerization threshold E for polymer crosslinking. th Establish the longitudinal critical equation:

[0027] ;

[0028] Among them, E eff (z) represents the effective cumulative exposure dose at depth z within the photosensitive material, Δt represents the total exposure time in a single dwell exposure state, M(ζ, t) represents the normalized concentration of the photoinitiator that has not yet decomposed at the corresponding spatial depth ζ and time t, ζ represents the virtual real variable that performs the spatial energy decay integral along the material depth direction, and E th This represents the critical polymerization threshold for polymer crosslinking.

[0029] The above longitudinal critical equation is analyzed to obtain the limiting physical depth that ensures continuous bonding between interlayer lattices, and it is rounded down to establish it as the discrete thickness d3 of a single layer.

[0030] The method for determining a specific distance d1 along the x-axis is as follows:

[0031] Introducing the Dill model elevates the method for determining the splicing spacing from a simple search of spatial geometric intersections to a solution of a spatiotemporally coupled nonlinear boundary value problem. The normalized initiator concentration M inside the photoresist follows a first-order reaction kinetic equation:

[0032] ;

[0033] Where M is the normalized initiator concentration, C is the photosensitivity coefficient of the photosensitive material, and I eff The effective driving light intensity in the x-direction of the elliptical Gaussian spot is given.

[0034] Because the splicing exposure area has undergone the initial light field irradiation, the normalized initiator concentration has decreased to M1(r), and the local absorption coefficient has increased; the effective driving light intensity for deposition in this area during the second exposure is... Forming a sequential coupling state:

[0035] ;

[0036] in, , where A is the initial spatial interference light intensity at the target coordinates during the second exposure, A is the bleaching coefficient characterizing the degree of transparency of the medium, and B is the unbleachable basic absorption coefficient;

[0037] After K exposures, the final photoacid concentration in the x-axis splicing region is... It is necessary to cross the acid production concentration threshold A required to achieve polymerization. th :

[0038] ;

[0039] Where m is the discrete exposure number index, C is the inherent photosensitivity constant of the photosensitive material, and t m-1 With t m This represents the start and end times of the m-th exposure. Let be the local interference incident light intensity during the m-th exposure. To effectively drive the light intensity at spatial coordinate r during the m-th exposure, A dynamically evolves with time τ. th This represents the critical threshold for the concentration of photosensitive acid in polymer crosslinking.

[0040] The smooth distribution of microscopic acid latent images is achieved by macroscopic mechanical stepping, and the specific distance d1 along the x-axis is calculated under the smoothing constraint.

[0041] The method for determining the step distance d2 along the y-direction is as follows:

[0042] Two-dimensional matrix stitching leads to complex overlapping of intersecting grids in the Gaussian envelope along the x and y directions. By introducing chemical state constraints within the global two-dimensional plane, a global photoacid concentration field peak-valley non-uniformity model is constructed.

[0043] ;

[0044] Where U represents the peak-valley nonuniformity of the photoacid concentration field in the global two-dimensional array, [Acid] is the global photoacid concentration distribution function accumulated at each spatial coordinate point within the evaluation domain after exposure through multiple rows of overlapping grids, and Ω is the two-dimensional integral evaluation domain covering the overlapping areas of adjacent rows. th The maximum allowable variation threshold for the splicing region;

[0045] The Gaussian envelope feature radius is extracted, and the step distance d2 along the y-direction that simultaneously satisfies the continuity and uniformity criteria is derived through global iterative optimization.

[0046] Furthermore, the method may also include:

[0047] When it is necessary to inject topological defects into a fixed point inside the crystal lattice, the piezoelectric stick-slip precision motion system carries the material to be processed and steps to the preset defect target coordinates and establishes a static self-locking state. The laser activation signal is temporarily suspended, and the beam control custom frame inside the 4F collimation-beam control-focusing module is manipulated. By mechanically rotating the first set of half-wave plates and the second set of polarizers located on a specific sub-optical path, the polarization angle and optical power of the local light waves participating in spatial interference are reconstructed, generating a local variation light field different from the initial crystal lattice pattern. The laser is then activated to perform distorted light field exposure at the local coordinate point. After the exposure ends and the laser signal is cut off, the half-wave plates and polarizers in the beam control custom frame are reset to the initial state.

[0048] The method for determining the polarization angle and optical power control is as follows:

[0049] Based on electromagnetic theory and the principle of plane wave superposition, the intensity distribution of an ideal spatial interference light field can be expressed as:

[0050] ;

[0051] Where I represents the interference light intensity distribution at spatial coordinate point r, r is the three-dimensional spatial position coordinate vector, i and j are the sub-beam indices participating in the interference, and A i With A j e represents the electric field amplitude corresponding to the sub-beam. i With e j To determine the electric field polarization direction vector for the interference polarization condition, k i With k j Let φ be the spatial wave vector. i With φ j This is the initial phase;

[0052] Therefore, based on the desired pattern and known optical field parameters, the polarization vector can be calculated inversely, and thus the polarization angle can be obtained;

[0053] The formula for controlling optical power by combining polarization angle and half-wave plate, obtained from Malusian quantification, is as follows:

[0054] ;

[0055] Among them, I in I represents the initial optical power of the initial beam before it enters the half-wave plate. out Let θ be the output optical power of the light beam after it passes through a half-wave plate and a polarizer in sequence. hLet θ be the initial beam polarization direction and the fast axis deviation of the half-wave plate. p The initial beam polarization direction is offset from the transmission axis of the linear polarizer by an angle.

[0056] Finally, this application also provides the application of the above-mentioned multi-beam laser interference lithography method for periodic three-dimensional micro / nano structures, using the method to realize the fabrication of customized functional photonic devices and micro / nano sensor devices.

[0057] The beneficial technical effects of this invention are as follows:

[0058] 1. This invention overcomes the physical constraints of laser spot size through two-dimensional planar splicing exposure and overcomes the depth-of-field limitation of single interference light field through layer-by-layer exposure in the thickness direction, ultimately achieving high-fidelity manufacturing of micro-nano structures that combine large-area macroscopic dimensions with periodic micro-nano patterns. During photolithography, the dynamic depth light intensity under the coupling effect of Gaussian light field and photosensitive material is solved to accurately solve the longitudinal discrete thickness d3, overcoming the depth-of-field limitation to ensure interlayer continuity. By strictly controlling the in-plane step distances d1 and d2, the nonlinear photobleaching response of the material is driven to actively compensate for the energy attenuation at the Gaussian distribution edges, achieving seamless splicing of macroscopic patterns. In addition, by independently controlling the polarization angle and optical power of the beam in situ, the controllable introduction of complex topological functional defects into large-area periodic micro-nano structures is achieved while maintaining the macroscopic stepping sequence.

[0059] 2. This invention uses a 532 nm green single-mode continuous laser, which has the characteristics of high coherence length, high penetration, low power jitter, visualization and low cost. It can simultaneously meet the manufacturing requirements of high aspect ratio and high stability periodic three-dimensional micro-nano structures, while reducing the difficulty of system optical path adjustment and integration cost.

[0060] 3. This invention uses a monolithic diffraction element (DOE) to spatially modulate and diffract the wavefront of a single incident Gaussian beam into N sub-beams and 1 central beam, i.e., an umbrella-shaped N+1 beam configuration, based on the principle of wavefront division. This ensures the accuracy of the parameters of the N+1 sub-beams, which can greatly reduce the number of system components, space size and cost, and improve the system compactness and integration.

[0061] 4. The 4F collimation-beam control-focusing module of the present invention can ensure that the optical path of N sub-beams is consistent and the phase difference of N+1 sub-beams is constant, improving the compactness of the optical path and the anti-interference ability. The 4F collimation-beam control-focusing module can achieve collimation and focusing of multiple beams within a small optical path, effectively suppressing the laser quality degradation caused by beam divergence, and ensuring the morphological stability and repeatability of manufacturing periodic three-dimensional micro-nano structures. Moreover, the 4F collimation-beam control-focusing module can independently control the polarization angle and optical power of a single beam, meeting the diverse manufacturing needs of periodic three-dimensional micro-nano structures.

[0062] 5. The piezoelectric stick-slip precision motion system of the present invention, equipped with a sample stage, has advantages such as centimeter-level stroke, nanometer-level precision, static self-locking with zero thermal drift, extremely high rigidity and compactness, vacuum compatibility and simple control. During the splicing photolithography process, it can ensure high precision, high efficiency and high stability splicing in large areas, ensure the morphology of the splicing area, and improve the stability and compactness of the system.

[0063] 6. The multi-beam laser interference lithography system for large-area periodic three-dimensional micro-nano structures of the present invention can simultaneously realize splicing manufacturing and adjustment of interference light field parameters, that is, it has the ability to manufacture large-area, controllable defects in periodic three-dimensional micro-nano structures. Attached Figure Description

[0064] Figure 1 A schematic diagram of the structure of the multi-beam laser interference lithography system for the periodic three-dimensional micro / nano structure provided in Embodiment 1 of the present invention;

[0065] Figure 2(a) is a schematic diagram of the optical path propagation of the diffraction element generating N+1 diffraction beams and the 4F collimation-beam control-focusing module provided in Embodiment 1 of the present invention.

[0066] Figure 2(b) is a schematic diagram of the optical path propagation of the 4F collimation-beam control-focusing module provided in Embodiment 1 of the present invention;

[0067] Figure 3(a) is a schematic diagram of the structural pattern generated by multi-beam laser interference without a central beam, provided in Embodiment 2 of the present invention;

[0068] Figure 3(b) is a schematic diagram of the structural pattern generated by N+1 beam interference provided in Embodiment 2 of the present invention;

[0069] Figure 4 This is a schematic diagram of the piezoelectric stick-slip precision motion system provided in Embodiment 1 of the present invention;

[0070] Figure 5(a) is a schematic diagram of the dry film photosensitive material, which is considered to be a z-axis multilayer structure, provided in Embodiment 2 of the present invention;

[0071] Figure 5(b) is a schematic diagram of the alternating working principle of large-area manufacturing step-static-exposure provided in Embodiment 2 of the present invention;

[0072] Figure 6 A schematic diagram of laser and x-axis piezoelectric stick-slip actuator signals during large-area manufacturing, as provided in Embodiment 2 of the present invention;

[0073] Figure 7 A schematic diagram of laser and y-axis piezoelectric stick-slip actuator signals during large-area manufacturing, as provided in Embodiment 2 of the present invention;

[0074] Figure 8A schematic diagram of laser and z-axis piezoelectric stick-slip actuator signals during large-area manufacturing, as provided in Embodiment 2 of the present invention;

[0075] in,

[0076] In Figure 2(b), f1 represents the focal length of the first Fourier transform lens and f2 represents the focal length of the second inverse Fourier transform lens. Detailed Implementation

[0077] Example 1

[0078] This embodiment discloses a multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures. The system includes a 532 nm green single-longitudinal-mode continuous laser 1, a diffraction element 4, a 4F collimation-beam control-focusing module 5, a piezoelectric stick-slip precision motion system 6, and an optical path base 8.

[0079] Specifically, such as Figure 1 As shown, the optical path base 8 is mounted on the optical vibration isolation platform. In this embodiment, the optical vibration isolation platform serves as the core support foundation. Its main function is to provide a statically collimated and dynamically stable physical environment for the system. It isolates external micro-vibrations and suppresses internal resonance through a honeycomb structure and air springs, ensuring stable optical path difference and preventing interference pattern drift and blurring. The 532 nm green single-longitudinal-mode continuous laser is mounted on the optical vibration isolation platform through connectors, generating a continuous-wave single-longitudinal-mode Gaussian distributed laser beam. The laser beam optical axis is horizontal, and the optical power is adjustable from 0 to 200 mW.

[0080] In this embodiment, considering that the laser is relatively heavy and has a heat dissipation module, it will vibrate. The higher it is installed, the more it may sway (the optical path base is similar to a cantilever, the higher it is, the longer the lever arm is, and the easier it is to sway). The closer it is to the main optical path, the greater the impact on the optical path. Therefore, it is installed on an optical vibration isolation platform, and the optical path is adjusted by setting the first reflector 2 and the second reflector 3 to reduce the impact of vibration.

[0081] The first reflector 2 is mounted on the first optical guide rail 7-1 via an optical mount and a slider. The first optical guide rail 7-1 is mounted on the optical vibration isolation platform via bolts. The first reflector 2 changes the propagation direction of the laser beam and propagates it to the second reflector 3.

[0082] The second reflector 3 is mounted on the second optical guide rail 7-2 via an optical mount and a slider. The second optical guide rail 7-2 is mounted on the optical path base 8 via bolts. The second reflector 3 changes the propagation direction of the laser beam, so that the optical axis of the laser beam is perpendicular to the mirror surface of the diffraction element 4 and coincides with the center.

[0083] As shown in Figure 2(a), the diffraction element 4 is mounted on the second optical guide rail 7-2 via an optical mirror mount and a slider. The diffraction element 4 modulates and diffracts the wavefront of a single vertically incident Gaussian beam in space into N sub-beams and 1 central beam that are centrally symmetrically distributed, i.e., an umbrella-shaped N+1 beam configuration.

[0084] As shown in Figure 2(b), the 4F collimation-beam control-focusing module 5 includes a first Fourier transform lens 5-1, a beam control custom frame 5-2 located on the back focal plane (Fourier spectrum plane) of the first Fourier transform lens 5-1, and a second inverse Fourier transform lens 5-3, all arranged coaxially along the optical axis. The first Fourier transform lens 5-1, the beam control custom frame 5-2, and the second inverse Fourier transform lens 5-3 are all mounted on the second optical guide rail 7-2 via optical mounts and sliders. The first Fourier transform lens 5-1 collimates the umbrella-shaped N+1 beam generated by the diffraction element 4 into a parallel N+1 beam. The beam control custom frame 5-2 includes two sets of lenses along the optical axis: a first set of half-wave plates and a second set of polarizers. The polarization angle of the beam can be independently controlled by rotating the polarizers, and the beam power can be adjusted by rotating the half-wave plates. The second inverse Fourier transform lens 5-3 focuses the parallel N+1 beam onto the same point on the sample, forming a spatial interference light field and completing the exposure of the photosensitive material.

[0085] The sample can be mounted on a piezoelectric stick-slip precision motion system 6, which is installed on an optical vibration isolation platform via mechanical connectors. In this embodiment, the piezoelectric stick-slip precision motion system can be the piezoelectric stick-slip drive platform disclosed in patent "2025112791929". The piezoelectric stick-slip precision motion system 6 includes x-axis piezoelectric stick-slip actuators 6-1, y-axis piezoelectric stick-slip actuators 6-2, and z-axis piezoelectric stick-slip actuators 6-3, which are installed in series. Figure 4 As shown, the sample is mounted on the sample stage 6-4 at the end of the z-axis piezoelectric stick-slip actuator 6-3. The piezoelectric stick-slip precision motion system 6 can realize the three-dimensional precision motion of the sample. The single-step motion characteristics of general stick-slip actuators have a backlash phenomenon. Therefore, the piezoelectric stick-slip precision motion system 6 in this application can be used for both scanning interference lithography and static stitching lithography, and has high applicability.

[0086] Example 2

[0087] Based on the multi-beam laser interference lithography system for periodic three-dimensional micro-nano structures provided in Example 1, this example elaborates on the operation method of realizing large-area splicing manufacturing using the lithography system in Example 1, and deeply analyzes the core theoretical mechanism of this method to break through the limitations of traditional optical field of view and improve the extreme manufacturing scale.

[0088] The theoretical challenge of traditional multi-beam laser interferometry lithography lies in the fact that the area fabricated in a single operation is limited by the beam waist distribution boundary of the Gaussian beam and the attenuation of coherent energy density, which fundamentally restricts the continuous fabrication of micro- and nano-structures at the macroscopic scale. To overcome this optical field barrier, this embodiment constructs a step-stationary-exposure matrix stitching mechanism based on spatiotemporal decoupling and a spatiotemporally coupled photochemical evolution model to guide the operation; specifically as follows:

[0089] As shown in Figure 5(a), in the initial stage of operation, the target thickness of the periodic three-dimensional micro / nano structure is first determined, typically from tens to hundreds of micrometers. This requires exposure of a dry film photosensitive material of the corresponding thickness (such as SU-8 series photoresist, AZ series photoresist, etc., which can undergo photochemical reaction at the wavelength and power of a 532 nm green single-mode continuous laser). In three-dimensional space, the target thickness of the dry film photosensitive material is discretized as a multi-layer processing plane distributed along the z-axis, and the discrete thickness of a single layer in the z-axis is calculated. A dry film photosensitive material sample with a discrete thickness in the z-axis is obtained through conventional photolithography operations such as spin coating, scraping, and pre-baking. This sample is fixed to the sample stage 6-4 at the end of the piezoelectric stick-slip precision motion system 6. The z-axis piezoelectric stick-slip actuator 6-3 is controlled to adjust the position of the sample stage 6-4, ensuring that the sample surface is located at the multi-beam focal point on the optical axis. This ensures that the multi-beam spatial interference light field generated after passing through the second inverse Fourier transform lens 5-3 is precisely focused onto the surface of the dry film photosensitive material.

[0090] At time t0, exposure is performed at point 1 in the x-direction of the first layer in the z-axis. The x-axis piezoelectric stick-slip actuator 6-1 remains stationary. The system controls the 532 nm green single-mode continuous laser 1 to turn on the signal, and the interference light field resides inside the photosensitive material for exposure. The exposure time for a single exposure is determined by the laser wavelength, the absorption rate of the photosensitive material at that wavelength, the cumulative exposure dose, and the polymerization threshold of the photosensitive material. After the exposure is completed, the laser signal is turned off. In the dark field state with the laser off, the x-axis piezoelectric stick-slip actuator 6-1 is driven to move a specific distance d1 along the positive x-axis to the second point coordinate.

[0091] Given that the spatial interference light field exhibits an elliptical Gaussian distribution with high energy at the center and attenuation at the edges, the lateral movement distance d1 between adjacent points must be strictly set to be less than the effective physical radius of the interference spot in the x-direction. By detecting and theoretically reconstructing the spatial distribution of the Gaussian light field, the intensity distribution characteristics in the x-direction are extracted. Combined with the Dill kinetic equation, the nonlinear response of the photoresist under alternating exposure, historical absorption memory, and bleaching effects is quantified. That is, a spatiotemporally coupled photochemical evolution model is established to solve the mapping relationship between exposure parameters, splicing path spacing d1, and the final photoacid distribution. Ultimately, the reverse design of d1 under specific optical and material parameters is achieved. This strategy fundamentally eliminates the splicing discontinuity between discrete exposure fields by spatially forcing energy superposition compensation in the low-dose region at the edge, ensuring the continuous fusion of the micro / nano structure lattice at the matrix intersection.

[0092] Once the x-axis piezoelectric stick-slip actuator 6-1 reaches the second coordinate and establishes a static self-locking state with zero thermal drift, i.e., at time t1, the laser is reactivated to perform static exposure. After completion, the signal is disconnected, and the x-axis piezoelectric stick-slip actuator 6-1 continues to step in the x-direction to the third coordinate. This coordinated action is repeated alternately until the full-point exposure of a single row in the x-direction is completed. Subsequently, at time t4, i.e., after the end of the exposure of the first layer in the z-direction and the first row in the x-direction, laser 1 is disconnected, driving the y-axis piezoelectric stick-slip actuator 6-2 to step a distance d2 in the y-direction to the negative starting coordinate of the second row in the x-direction. Similarly, the longitudinal movement distance d2 must also be less than the physical radius of the spot in the y-direction. The intensity distribution characteristics of the Gaussian light field in the y-direction are extracted, and d2 under specific optical and material parameters is solved using a spatiotemporally coupled photochemical evolution model. Then, drive the x-axis piezoelectric stick-slip actuator 6-1 along the -x direction at a distance d1 to expose the second negative point. Repeat the above process to complete the exposure of the second row of points. Repeat this process until the global matrix exposure of the first layer of the two-dimensional plane in the z direction is completed.

[0093] In t n At a certain moment, the processing of the first layer in the z-direction is completed. The sample is removed from the sample stage 6-4 and, through conventional photolithography operations such as spin coating, scraping, and pre-baking, a single-layer dry film photosensitive material with discrete thickness in the z-direction is added to the surface of the current sample. The sample is then reinstalled in its original position on the sample stage 6-4. The z-direction piezoelectric stick-slip actuator 6-3 is driven to step a distance d3 along the z-direction to the unexposed second layer in the z-direction, restarting the planar matrix stitching process. A longitudinal attenuation function for single exposure energy is constructed by combining the Gaussian depth of focus and the dielectric absorption coefficient. The cumulative total of photochemical reactions at the interface between adjacent exposure layers is calculated. By precisely triggering the critical polymerization threshold for polymer crosslinking with the cumulative reaction amount at the interface, a critical equation is established and analyzed to obtain the maximum limiting step distance d3 that ensures the longitudinal physical continuity of the three-dimensional lattice. This process is repeated until the layer-by-layer additive manufacturing and full exposure of the thick dry film photosensitive material are completed. After exposure, the material undergoes conventional chemical processing steps such as post-baking and development to achieve a subtractive process, exhibiting a periodic double-continuous porous structure in space.

[0094] Detailed

[0095] The method for determining the z-axis single-layer discrete thickness d3 is as follows:

[0096] The energy deposition of the multi-beam interference optical field in the z-axis direction is controlled by both the Rayleigh depth of focus divergence of the Gaussian beam and the physical absorption characteristics of the photosensitive medium.

[0097] First, construct the spatial Gaussian envelope interference light field distribution function I of the umbrella-shaped N+1 beam. total (r), the light field distribution function is determined by the fundamental Gaussian envelope number I. gauss (r) and the number of high-frequency coherent superposition terms I int(r) Product structure:

[0098] ;

[0099] ;

[0100] ;

[0101] In the formula, w0 is the waist radius of the Gaussian beam, w(z) is the characteristic radius that varies with depth, I0 is the central peak intensity, r is the three-dimensional spatial coordinate vector, i and j are the sub-beam indices participating in the interference, and A i With A j e represents the electric field amplitude corresponding to the sub-beam. i With e j To determine the electric field polarization direction vector for the interference polarization condition, k i With k j Let φ be the spatial wave vector. i With φ j Let x, y, and z be the initial phase, and let r be the three-dimensional coordinates of the spatial coordinate r.

[0102] At this stage, the origin axis (x=0, y=0) is locked, and a dynamic depth light intensity distribution model is established. Since the dynamic absorption coefficient α of the photoresist decreases with the consumption of local acid-generating agents, the effective photochemical cumulative dose at the interface of adjacent exposure layers precisely reaches the critical polymerization threshold E for initiating polymer crosslinking. th Establish the longitudinal critical equation:

[0103]

[0104] Among them, E eff (z) represents the effective cumulative exposure dose at depth z within the photosensitive material, Δt represents the total exposure time in a single dwell exposure state, M(ζ, t) represents the normalized concentration of the photoinitiator that has not yet decomposed at the corresponding spatial depth ζ and time t, ζ represents the virtual real variable that performs the spatial energy decay integral along the material depth direction, and E th This represents the critical polymerization threshold for polymer crosslinking.

[0105] By analyzing the above longitudinal critical equation, the limiting physical depth that ensures continuous bonding of interlayer lattices is obtained, and it is rounded down to establish the longitudinal discrete thickness d3.

[0106] After obtaining the longitudinal discrete thickness d3, a rigid longitudinal boundary is set for subsequent planar deduction.

[0107] The method for determining the distance d1 to move along the x-axis is as follows:

[0108] After d3 is established, the spatial calculation dimension is reduced to the xy two-dimensional plane. Since the interference light field is macroscopically Gaussian distributed, a single exposure cannot provide sufficient exposure dose at the edge of the light field. When the piezoelectric stick-slip precision motion system moves along the x-axis by d1 to perform an adjacent exposure, the attenuation tail of the subsequent Gaussian envelope overlaps with the previous exposure area in space.

[0109] Introducing the Dill model elevates the method for determining the splicing spacing from a simple search of spatial geometric intersections to a solution of a spatiotemporally coupled nonlinear boundary value problem. The normalized initiator concentration M inside the photoresist follows a first-order reaction kinetic equation:

[0110]

[0111] Where M is the normalized initiator concentration, C is the photosensitivity coefficient of the photosensitive material, and I ef The effective driving light intensity in the x-direction of the elliptical Gaussian spot is given.

[0112] Since the splicing exposure area (i.e., the area adjacent to x = d1 / 2) has undergone the initial light field irradiation, the normalized initiator concentration has decreased to M1(r), and the local absorption coefficient has increased; the effective driving light intensity for deposition in this area during the second exposure is... Forming a sequential coupling state:

[0113]

[0114] in, denoted as the initial spatial interference light intensity at the target coordinates during the second exposure, A is the bleaching coefficient characterizing the degree of transparency of the medium, and B is the fundamental absorption coefficient that cannot be bleached.

[0115] After K exposures, the final photoacid concentration in the x-axis splicing region is... It is necessary to cross the acid production concentration threshold A required to achieve polymerization. th :

[0116]

[0117] Where m is the discrete exposure number index, C is the inherent photosensitivity constant of the photosensitive material, and t m-1 With t m This represents the start and end times of the m-th exposure. Let be the local interference incident light intensity during the m-th exposure. To effectively drive the light intensity at spatial coordinate r during the m-th exposure, A dynamically evolves with time τ. th This represents the critical threshold for the concentration of photosensitive acid in polymer crosslinking.

[0118] This method breaks through the scalar superposition of optical dose, considers the nonlinear photobleaching and photochemical reaction kinetics of materials, and actively compensates for the spatial photoacid distribution distortion caused by macroscopic Gaussian distribution splicing; the process achieves smooth distribution of microscopic photoacid latent image through macroscopic mechanical stepping, and inversely calculates the optimal splicing spacing d1 under the smoothing constraint.

[0119] The method for determining the step distance d2 along the y-direction is as follows:

[0120] After obtaining d1, the distribution of a single-row one-dimensional photoacid latent image is determined. The calculation dimension is expanded to the region stitching of two adjacent rows to solve for the y-axis step distance d2:

[0121] Two-dimensional matrix stitching leads to complex overlapping of intersecting grids in the Gaussian envelope along the x and y directions. By introducing chemical state constraints within the global two-dimensional plane, a global photoacid concentration field peak-valley non-uniformity model is constructed.

[0122]

[0123] Where U represents the peak-valley nonuniformity of the photoacid concentration field in the global two-dimensional array, [Acid] is the global photoacid concentration distribution function accumulated at each spatial coordinate point within the evaluation domain after exposure through multiple rows of overlapping grids, and Ω is the two-dimensional integral evaluation domain covering the overlapping areas of adjacent rows. th The maximum permissible variation threshold for the splicing region.

[0124] The Gaussian envelope feature radius is extracted, and the limiting longitudinal splicing spacing d2 that simultaneously satisfies the continuity and uniformity standards is derived through global iterative optimization.

[0125] At this point, the solution for the three-dimensional splicing step distance is complete, establishing the constraint boundary for the fabrication of large-area three-dimensional periodic micro-nano structures.

[0126] Of course, it should be noted that due to the inherent instability and measurement error of optical and material parameters, taking the actual operation of SU-8 negative photoresist splicing manufacturing as an example, the solved d1, d2, d3 may deviate from the ideal values. Therefore, it is possible to further optimize the theoretical values ​​based on the solved d1, d2, d3 through pre-experiments and other methods.

[0127] As shown in Figures 3(a) and 3(b), when there is no central beam, i.e., N-beam interference (N not less than 3), the light field pattern generated by multi-beam laser interference is a 2D pattern; when there is N+1 beam interference (N not less than 3), the light field pattern generated by multi-beam laser interference is a 3D pattern. In existing research, the area of ​​the fabricated periodic micro / nanostructures is limited due to the extreme manufacturing scale. Even when fabricating 3D patterns under the N+1 beam interference configuration, the insufficient three-dimensional manufacturing capability results in a smaller structure thickness, leading to fewer periods in the thickness direction, which affects the performance of the periodic micro / nanostructures. This method can achieve the fabrication of large-area, high aspect ratio 2D patterned periodic micro / nanostructures by adjusting the optical power of the central beam to an extremely low level, and can also achieve the fabrication of large-area three-dimensional 3D patterned periodic micro / nanostructures.

[0128] The innovation of this method lies in the fact that the two-dimensional continuous processing area is completely free from the physical constraints of optical aperture. The macroscopic boundary is only limited by the limit of the motion platform. The longitudinal structural thickness is achieved by physical layering and superposition of discrete planes, breaking through the depth of field limitation of single interference light field. Ultimately, high-fidelity manufacturing of periodic three-dimensional micro-nano structures with both macroscopic physical size and micro-lattice characteristics is realized, which greatly improves the extreme manufacturing scale.

[0129] Example 3

[0130] In this embodiment, based on the matrix splicing mechanism of Embodiment 2, the specific operational steps for achieving controllable defect manufacturing are explained, and the in-situ parameter control innovation of this invention in the fields of customized functional photonic device manufacturing and multifunctional sensor devices is highlighted.

[0131] For core optical devices such as photonic crystals, perfectly periodic structures cannot form effective photonic bandgap defect states. For micro / nano sensors, a single periodic structure cannot detect different biomolecules. Existing interference lithography techniques can typically only generate uniform periodic structures across the entire field of view, making it difficult to inject topological defects into the crystal lattice at specific points during macroscopic fabrication, thus failing to meet the application requirements for controllable local defects. This embodiment breaks through the manufacturing bottleneck of uniform structures across the entire field of view by embedding a microscopic in-situ parameter control mechanism in the macroscopic array splicing process.

[0132] Before implementation, the defect topology coordinate matrix inside the device is pre-planned according to the required photonic device functional mapping diagram. Exposure is continuously performed at most conventional coordinate points following the parameter settings of Example 2 (d1, d2, d3 stepping and timing coordination) to construct a basic three-dimensional periodic lattice. When the piezoelectric stick-slip precision motion system 6, equipped with photosensitive material, steps to the preset defect target coordinates and establishes a static self-locking state, the system temporarily delays triggering the laser 1's on-time signal. At this time, the beam control custom frame 5-2 inside the 4F collimation-beam control-focusing module 5 is manipulated. By mechanically rotating the first set of half-wave plates and the second set of polarizers located on a specific sub-optical path, the polarization angle and optical power distribution of the local light waves participating in spatial interference are independently reconstructed from the physical source, generating a locally varying light field different from the initial lattice pattern. The polarization angle and optical power adjustment amounts need to be based on electromagnetic theory and the principle of plane wave superposition, and are inversely calculated in conjunction with the target light field pattern required at the defect point. Specifically...

[0133] Based on electromagnetic theory and the principle of plane wave superposition, the intensity distribution of an ideal spatial interference light field can be expressed as:

[0134] ;

[0135] Where I represents the interference light intensity distribution at spatial coordinate point r, r is the three-dimensional spatial position coordinate vector, i and j are the sub-beam indices participating in the interference, and A i With A j e represents the electric field amplitude corresponding to the sub-beam. i With e j To determine the electric field polarization direction vector for the interference polarization condition, k i With k j Let φ be the spatial wave vector. i With φ j This is the initial phase.

[0136] Therefore, based on the desired pattern and known optical field parameters, the polarization vector can be calculated inversely, and thus the polarization angle can be obtained;

[0137] The formula for controlling optical power by combining polarization angle and half-wave plate, obtained from Malusian quantification, is as follows:

[0138] ;

[0139] Among them, I in I represents the initial optical power of the initial beam before it enters the half-wave plate. out Let θ be the output optical power of the light beam after it passes through a half-wave plate and a polarizer in sequence. h Let θ be the initial beam polarization direction and the fast axis deviation of the half-wave plate. p The initial beam polarization direction is offset from the transmission axis of the linear polarizer by an angle.

[0140] Therefore, the polarizer is first adjusted to the desired polarization angle, and then the half-wave plate is rotated to adjust the optical power, so as to realize the in-situ reconstruction of the beam parameters and obtain the target optical field pattern of the controllable defect point.

[0141] After completing the beam parameter modulation and interference field reconstruction, laser 1 is switched on to perform distorted light field exposure at the local coordinate point. Once the exposure at this specific point is complete and the laser 1 signal is cut off, the half-wave plate and polarizer within the beam control custom frame 5-2 are reset to their initial state. Subsequently, the piezoelectric stick-slip precision motion system 6 is driven to the next coordinate point, and the standard periodic pattern splicing process is resumed. The innovation of this implementation method lies in its ability to deeply couple the independent modulation capability of the 4F collimation-beam control-focusing module 5 without interrupting the overall macroscopic matrix splicing manufacturing sequence. This enables precise embedding of local point defects or specific wiring defects within a continuous three-dimensional periodic lattice medium, greatly expanding the limits of controllable defect manufacturing capabilities.

[0142] It should be noted that the multi-beam laser interference lithography system for large-area periodic three-dimensional micro-nano structures in this application can realize the fabrication of theoretically infinitely large-area periodic three-dimensional micro-nano structures, breaking through the optical field limitations of traditional lithography. Furthermore, by controlling the beam parameters in real time, the optical field parameters can be adjusted during splicing manufacturing. Therefore, the multi-beam laser interference lithography system for large-area periodic three-dimensional micro-nano structures in this application has the capability to manufacture large-area, controllable defects.

[0143] In summary, the multi-beam laser interference lithography system for large-area periodic three-dimensional micro / nano structures of the present invention can achieve large-area, high-precision, high-efficiency, high-controllability, and diversified manufacturing of periodic three-dimensional micro / nano structures. The optical path based on the wavefront division principle features high compactness, consistent optical path difference between each beam, and independent controllability of individual optical path parameters. This gives the manufacturing system high integration, high stability, and diversified manufacturing capabilities. By controlling the piezoelectric stick-slip precision motion system and laser on / off switching, the splicing manufacturing of large-area periodic three-dimensional micro / nano structures can be achieved, improving the system's extreme manufacturing scale, three-dimensional structure manufacturing capabilities, and controllable defect manufacturing capabilities.

[0144] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures, characterized in that, The system includes a laser, a diffraction element, a 4F collimation-beam control-focusing module, and a piezoelectric stick-slip precision motion system; The laser emits a single Gaussian beam that is perpendicularly incident on a diffraction element. The diffraction element modulates and diffracts the wavefront of the single perpendicularly incident Gaussian beam in space into N sub-beams and 1 central beam that are centrally symmetrically distributed, forming an umbrella-shaped N+1 beam configuration, wherein N is not less than 3. The 4F collimation-beam control-focusing module includes a first Fourier transform lens, a custom beam control frame, and a second inverse Fourier transform lens arranged coaxially along the optical axis. The first Fourier transform lens collimates the umbrella-shaped N+1 beam generated by the diffraction element into a parallel N+1 beam. The custom beam control frame includes two sets of lenses along the optical axis: a first set of half-wave plates and a second set of polarizers. The polarization angle of the beam is independently controlled by rotating the polarizers, and the beam power is adjusted by rotating the half-wave plates. The second inverse Fourier transform lens focuses the parallel N+1 beam onto the same point on the sample. The sample is mounted on a piezoelectric stick-slip precision motion system. The photolithography of the sample is completed by spatial interference combined with the movement of the piezoelectric stick-slip precision motion system.

2. The multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures according to claim 1, characterized in that: The piezoelectric stick-slip precision motion system includes three series-connected single-degree-of-freedom piezoelectric stick-slip actuators. The sample is mounted at the end of the Z-axis piezoelectric stick-slip actuator, and the piezoelectric stick-slip precision motion system is used to realize the three-dimensional spatial motion of the sample.

3. The multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures according to claim 1, characterized in that: The laser is a green single-mode continuous laser.

4. The multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures according to claim 1, characterized in that: The system also includes at least one reflector installed between the laser emitting end and the diffraction element incident end. The reflector reflects the laser emitted by the laser, so that the laser beam is perpendicular to the diffraction element and coincides with the center of the diffraction element.

5. The multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures according to claim 1, characterized in that: The spacing between the first Fourier transform lens, the customized beam control frame, and the second inverse Fourier transform lens of the 4F collimation-beam control-focusing module is adjustable, so that the positional relationship of the 4F collimation-beam control-focusing module meets the requirements of the 4F principle.

6. A method for photolithography using a multi-beam laser interference lithography system for periodic three-dimensional micro / nano structures as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Determine the target thickness for manufacturing periodic three-dimensional micro / nano structures. Discretize the target thickness of the material to be processed in three-dimensional space as a multi-layer processing plane distributed along the z-direction, and calculate the discrete thickness d3 of a single layer in the z-direction. S2. Perform z-axis first layer x-axis exposure; when exposing z-axis first layer x-axis first row first point, the piezoelectric stick-slip precision motion system remains stationary, the control laser signal is turned on, the interference light field resides inside the photosensitive material for exposure, after the exposure is completed, the control laser signal is turned off, and then the piezoelectric stick-slip precision motion system is driven to move a specific distance d1 along the positive x-axis to the second point, and the z-axis first layer x-axis second point is exposed, and so on to complete the single row full point exposure of x-axis first row; S3, drive the piezoelectric stick-slip precision motion system to step a distance d2 in the y direction to the negative starting coordinate of the second row in the x direction, complete the point exposure of the second row along the -x direction, repeat in sequence until the full-domain matrix exposure of the first layer of two-dimensional plane in the z direction is completed; S4. Remove the sample, add a single layer of material with discrete thickness in the z-direction to be processed to the upper surface of the current sample, and install it back in its original position; Repeat steps S2 and S3 to complete the global matrix exposure of the second two-dimensional plane in the z direction; repeat this process until the layer-by-layer additive manufacturing and full exposure of the material to be processed are completed.

7. The multi-beam laser interference lithography method for periodic three-dimensional micro / nano structures according to claim 6, characterized in that: The method for determining the z-axis single-layer discrete thickness d3 is as follows: First, construct the spatial Gaussian envelope interference light field distribution function I of the umbrella-shaped N+1 beam. total (r): ； In the formula, w0 is the waist radius of the Gaussian beam, w(z) is the characteristic radius that varies with depth, I0 is the central peak intensity, r is the three-dimensional spatial coordinate vector, i and j are the sub-beam indices participating in the interference, and A i With A j e represents the electric field amplitude corresponding to the sub-beam. i With e j To determine the electric field polarization direction vector for the interference polarization condition, k i With k j Let φ be the spatial wave vector. i With φ j Let x, y, and z be the initial phase, and let r be the three-dimensional coordinates of the spatial coordinate r. Because the dynamic absorption coefficient α of the photoresist decreases with the consumption of local acid-generating agents, the effective photochemical cumulative dose at the interface of adjacent exposure layers reaches the critical polymerization threshold E for polymer crosslinking. th Establish the longitudinal critical equation: ； Among them, E eff (z) represents the effective cumulative exposure dose at depth z within the photosensitive material, Δt represents the total exposure time in a single dwell exposure state, M(ζ, t) represents the normalized concentration of the photoinitiator that has not yet decomposed at the corresponding spatial depth ζ and time t, ζ represents the virtual real variable that performs the spatial energy decay integral along the material depth direction, and E th This represents the critical polymerization threshold for polymer crosslinking. The above longitudinal critical equation is analyzed to obtain the limiting physical depth that ensures continuous bonding between interlayer lattices, and it is rounded down to establish it as the discrete thickness d3 of a single layer. The method for determining a specific distance d1 along the x-axis is as follows: Introducing the Dill model elevates the method for determining the splicing spacing from a simple search of spatial geometric intersections to a solution of a spatiotemporally coupled nonlinear boundary value problem. The normalized initiator concentration M inside the photoresist follows a first-order reaction kinetic equation: ； Where M is the normalized initiator concentration, C is the photosensitivity coefficient of the photosensitive material, and I eff The effective driving light intensity in the x-direction of the elliptical Gaussian spot is given. Because the splicing exposure area has undergone the initial light field irradiation, the normalized initiator concentration has decreased to M1(r), and the local absorption coefficient has increased; the effective driving light intensity for deposition in this area during the second exposure is... Forming a sequential coupling state: ； in, , where A is the initial spatial interference light intensity at the target coordinates during the second exposure, A is the bleaching coefficient characterizing the degree of transparency of the medium, and B is the unbleachable basic absorption coefficient; After K exposures, the final photoacid concentration in the x-axis splicing region is... The acid production concentration threshold A required to achieve polymerization needs to be exceeded. th : ； Where m is the discrete exposure number index, C is the inherent photosensitivity constant of the photosensitive material, and t m-1 With t m This represents the start and end times of the m-th exposure. Let be the local interference incident light intensity during the m-th exposure. To effectively drive the light intensity at spatial coordinate r during the m-th exposure, A dynamically evolves with time τ. th This represents the critical threshold for the concentration of photosensitive acid in polymer crosslinking. The smooth distribution of microscopic acid latent images is achieved by macroscopic mechanical stepping, and the specific distance d1 along the x-axis is calculated under the smoothing constraint. The method for determining the step distance d2 along the y-direction is as follows: Two-dimensional matrix stitching leads to complex overlapping of intersecting grids in the Gaussian envelope along the x and y directions. By introducing chemical state constraints within the global two-dimensional plane, a global photoacid concentration field peak-valley non-uniformity model is constructed. ； Where U represents the peak-valley nonuniformity of the photoacid concentration field in the global two-dimensional array, [Acid] is the global photoacid concentration distribution function accumulated at each spatial coordinate point within the evaluation domain after exposure through multiple rows of overlapping grids, and Ω is the two-dimensional integral evaluation domain covering the overlapping areas of adjacent rows. th The maximum allowable variation threshold for the splicing region; The Gaussian envelope feature radius is extracted, and the step distance d2 along the y-direction that simultaneously satisfies the continuity and uniformity criteria is derived through global iterative optimization.

8. The multi-beam laser interference lithography method for periodic three-dimensional micro / nano structures according to claim 6, characterized in that: The method further includes: When it is necessary to inject topological defects into a fixed point inside the crystal lattice, the piezoelectric stick-slip precision motion system carries the material to be processed and steps to the preset defect target coordinates and establishes a static self-locking state. The laser activation signal is temporarily suspended, and the beam control custom frame inside the 4F collimation-beam control-focusing module is manipulated. By mechanically rotating the first set of half-wave plates and the second set of polarizers located on a specific sub-optical path, the polarization angle and optical power of the local light waves participating in spatial interference are reconstructed, generating a local variation light field different from the initial crystal lattice pattern. The laser is then activated to perform distorted light field exposure at the local coordinate point. After the exposure ends and the laser signal is cut off, the half-wave plates and polarizers in the beam control custom frame are reset to the initial state. The method for determining the polarization angle and optical power control is as follows: Based on electromagnetic theory and the principle of plane wave superposition, the intensity distribution of an ideal spatial interference light field can be expressed as: ； Where I represents the interference light intensity distribution at spatial coordinate point r, r is the three-dimensional spatial position coordinate vector, i and j are the sub-beam indices participating in the interference, and A i With A j e represents the electric field amplitude corresponding to the sub-beam. i With e j To determine the electric field polarization direction vector for the interference polarization condition, k i With k j Let φ be the spatial wave vector. i With φ j This is the initial phase; Therefore, based on the desired pattern and known optical field parameters, the polarization vector can be calculated inversely, and thus the polarization angle can be obtained; The formula for controlling optical power by combining polarization angle and half-wave plate, obtained from Malusian quantification, is as follows: ； Among them, I in I represents the initial optical power of the initial beam before it enters the half-wave plate. out Let θ be the output optical power of the light beam after it passes through a half-wave plate and a polarizer in sequence. h Let θ be the initial beam polarization direction and the fast axis deviation of the half-wave plate. p The initial beam polarization direction is offset from the transmission axis of the linear polarizer by an angle.

9. The application of the multi-beam laser interference lithography method for periodic three-dimensional micro / nano structures according to any one of claims 7-8, characterized in that: The method described above enables the fabrication of customized functional photonic devices and micro / nano sensor devices.

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