Surface exposure laser direct writing system and method

Abstract

The invention provides a surface exposure laser direct writing system and method. The system comprises a laser output module used for outputting first laser; the collimation and beam expansion module is arranged on a light path of the first laser and is used for expanding the original diameter of a light spot of the first laser to a preset diameter to obtain second laser; the spatial light modulation module is arranged on a light path of the second laser and used for modulating the second laser to obtain a light beam array corresponding to a holographic phase diagram of the target pattern, and the light beam array comprises a plurality of light beams; and the scanning direct-writing module is arranged on a light path of the light beam array, and is used for irradiating the light beam array on an interface combination part of the precursor solution and the substrate material, inducing a local reduction reaction and forming a metal structure at a multi-focus position. The second laser is modulated through the spatial light modulator, the single light beam can be split into the light beam array comprising the multiple light beams, the sample can be processed at the same time through the light beam array comprising the multiple light beams, and the laser direct writing efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to a surface exposure laser direct writing system and method. Background Art

[0002] Laser direct writing refers to the formation of a desired pattern on the material surface along the laser scanning path through the interaction between the laser and the material. Traditional laser direct writing methods mostly use galvanometer scanning or a translation stage to control the laser focus position for single-point serial processing, but this method has problems such as low efficiency and lack of flexibility.

[0003] Therefore, how to improve the efficiency of laser direct writing has become a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0004] The present application provides a surface exposure laser direct writing system and method, which are used to solve the technical problem of low efficiency of laser direct writing in the prior art.

[0005] In a first aspect, the present application provides a surface exposure laser direct writing system, comprising: A laser output module, used for outputting a first laser; A collimating and beam expanding module, arranged on the optical path of the first laser, for expanding the original diameter of the spot of the first laser to a preset diameter to obtain a second laser; A spatial light modulation module, arranged on the optical path of the second laser, for modulating the second laser to obtain a light beam array corresponding to the holographic phase diagram of the target pattern, wherein the light beam array includes a plurality of light beams; The scanning direct writing module is arranged on the optical path of the light beam array and is used for performing laser direct writing on the sample based on the light beam array to transfer the target pattern to the sample.

[0006] In some embodiments, an imaging module is also included; The imaging module is arranged between the spatial light modulation module and the scanning direct writing module, and is used to maintain the phase of the light beam array.

[0007] In some embodiments, the imaging module includes a first lens and a second lens; A first distance is between the first lens and the spatial light modulation module, and a second distance is between the first lens and the second lens; The first lens and the second lens have the same focal length, the first distance is equal to the focal length, and the second distance is equal to twice the focal length.

[0008] In some embodiments, the scanning direct writing module includes a galvanometer, which is used to adjust the spot position of the beam array so that the spot moves based on a preset path to form the target pattern on the sample.

[0009] In some embodiments, the laser output module includes a femtosecond laser, which is used to generate the first laser.

[0010] In some embodiments, the spatial light modulation module includes an amplitude-type and / or phase-type spatial light modulator.

[0011] In a second aspect, the present application provides a surface exposure laser direct writing method, which is applied to a surface exposure laser direct writing system. The surface exposure laser direct writing system includes a laser output module, a collimating and beam expanding module, a spatial light modulation module, and a scanning direct writing module. The method includes: Outputting the first laser based on the laser output module; Based on the collimating and beam expanding module, expanding the original diameter of the spot of the first laser to a preset diameter to obtain the second laser; Based on the spatial light modulation module, modulating the second laser to obtain a beam array corresponding to the holographic phase map of the target pattern, where the beam array includes multiple beams; Based on the scanning direct writing module, controlling the beam array to perform laser direct writing on the sample to transfer the target pattern to the sample.

[0012] In some embodiments, the holographic phase map is obtained after performing fast Fourier transform iteration on the target pattern.

[0013] In some embodiments, the holographic phase map includes the intensity and phase of the laser.

[0014] In some embodiments, the preset diameter is determined based on the liquid crystal surface size of the spatial light modulation module.

[0015] The surface exposure laser direct writing system and method provided by the embodiments of the present application output the first laser through the laser output module, and set a collimating and beam expanding module on the optical path of the first laser, and then expand the first laser to obtain the second laser; modulate the second laser through the spatial light modulator, and a single beam of light can be split into a beam array including multiple beams, and the sample can be processed simultaneously by the beam array of multiple beams, improving the laser direct writing efficiency; the spatial light modulation module can also change the beam distribution and shape of the second laser according to the holographic phase map of the target pattern to achieve flexible processing of the sample. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0017] Figure 1 One of the structural schematic diagrams of the surface exposure laser direct writing system provided by the embodiments of the present application; Figure 2 One of the flow schematic diagrams of the surface exposure laser direct writing system provided by the embodiments of the present application; Figure 3 The flow schematic diagram of the surface exposure laser direct writing method provided by the embodiments of the present application; Figure 4 The pattern formed on the sample surface based on the surface exposure laser direct writing method provided by the embodiments of the present application.

[0018] Explanation of reference numerals: 1. Laser output module; 11. Femtosecond laser; 2. Collimation and beam expansion module; 3. Spatial light modulation module; 31. Spatial light modulator; 4. Scanning direct writing module; 41. Galvanometer; 42. Three-axis displacement stage; 5. Imaging module; 51. First lens; 52. Second lens; 6. Reflecting mirror; 7. Attenuator. Detailed implementation manners

[0019] To make the objectives, technical solutions, and advantages of the present application clearer, the following will clearly and completely describe the technical solutions in the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present application belong to the scope of protection of the present application.

[0020] It should be noted that the terms "first", "second", etc. in this application are used to modify the components and parts claimed for protection. They do not themselves contain or represent any previous ordinal numbers for these components and parts, nor do they represent the sequence of manufacturing methods between one component and another. The use of these ordinal numbers is only to clearly distinguish one component or part with a certain name from another component or part with the same name. In addition, the terms "comprising" and "having" and any of their variations are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device comprising a series of steps or modules does not have to be limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products, or devices.

[0021] Figure 1 One of the structural schematic diagrams of the surface exposure laser direct writing system provided by the embodiments of this application; Figure 1 The lines between the modules in [figure] only represent that each module is arranged on the optical path. The lines are only examples and do not mean that the optical path is a straight line. The optical paths in different scenarios are different. As Figure 1 shown, the system includes: A laser output module 1 for outputting a first laser; A collimation and beam expansion module 2 arranged on the optical path of the first laser for expanding the original diameter of the light spot of the first laser to a preset diameter to obtain a second laser; A spatial light modulation module 3 arranged on the optical path of the second laser for modulating the second laser to obtain a beam array corresponding to the holographic phase diagram of the target pattern, and the beam array includes a plurality of beams; A scanning direct writing module 4 arranged on the optical path of the beam array for performing laser direct writing on a sample based on the beam array to transfer the target pattern to the sample.

[0022] Specifically, the laser output module 1 may include various types of lasers, and the lasers are used to generate the laser that can be used for subsequent laser direct writing. Corresponding lasers can be selected according to specific application scenarios.

[0023] For example, the laser output module 1 includes a femtosecond laser 11, and the femtosecond laser 11 is used to generate the first laser. The femtosecond laser 11 can generate femtosecond laser, and the femtosecond laser has an extremely short pulse width and high energy density, which is suitable for high-precision processing. A femtosecond laser 11 with a laser wavelength of 515 nm, a pulse width of 800 fs, a frequency of 600 kHz, a maximum laser power of 75 W, and a minimum laser power of 1.5 W can be selected.

[0024] The collimating and beam expanding module 2 can expand the original spot diameter of the first laser to a preset diameter to obtain the second laser. The spot diameter of the second laser is larger than that of the first laser.

[0025] The spatial light modulation module 3 may include a spatial light modulator 31. The spatial light modulator 31 is an optical element, usually composed of a liquid crystal panel, and is used to modulate the incident laser, that is, to modulate the second laser. Only when the spot diameter of the second laser can completely cover the liquid crystal surface of the spatial light modulator 31 can the spatial light modulator 31 uniformly modulate the entire second laser. If the spot diameter is smaller than the size of the liquid crystal surface, part of the liquid crystal surface will not be irradiated by the laser, resulting in non-uniform modulation and affecting the sample processing effect. Therefore, the preset diameter can be determined according to the size of the liquid crystal surface of the spatial light modulation module 3. For example, the preset diameter can be larger than the size of the liquid crystal surface, and the collimating and beam expanding module 2 expands the original spot diameter to cover the liquid crystal surface of the spatial light modulator 31 of the spatial light modulation module 3. For example, the preset size is set to 12 mm according to the conventional liquid crystal surface size.

[0026] The spatial light modulator 31 realizes light field regulation by modulating the arrangement of liquid crystal molecules. For example, the amplitude of the laser is modulated by the arrangement of pixel units, the phase of the laser is modulated by the refractive index, and the polarization state of the laser is modulated by the rotation of the polarization plane, so as to realize the modulation of the second laser. The spatial light modulator 31 has high programmability and can adjust the liquid crystal molecules in real time according to the feedback of the wavefront sensor to change the light field phase, with high flexibility. The spatial light modulator 31 can also modulate the Gaussian light into a flat-top light to solve the problem of non-uniform processing caused by the Gaussian distribution of the Gaussian light intensity along the radial direction, with high intensity in the central region of the spot and gradually decreasing intensity from the inside to the outside. The spatial light modulator 31 can split the light beam and arbitrarily adjust the beam shape to meet the processing requirements and greatly improve the processing efficiency. Since the structure of the spatial light modulator 31 is a reflective shaper, compared with the transmissive shaper, the spatial light modulator 31 absorbs less laser energy, has a small temperature drift and high long-term working stability, so it is an important tool for regulating the spot morphology and the laser energy density distribution.

[0027] The spatial light modulation module 3 may include an amplitude-type and / or a phase-type spatial light modulator 31. The amplitude-type spatial light modulator 31 modulates the amplitude of the second laser by changing the transmittance or reflectivity of each pixel. The phase-type spatial light modulator 31 modulates the phase of the second laser by changing the phase of each pixel. The specific spatial light modulator 31 can be selected according to the actual scenario.

[0028] The target pattern is the pattern to be directly written on the sample by laser. The holographic phase map is a phase distribution map that records the phase information of the laser on a certain plane. By loading the holographic phase map of the target pattern onto the spatial light modulator 31, the second laser can be modulated accordingly to achieve a specific optical effect.

[0029] The spatial light modulator 31 can modulate the second laser according to the loaded holographic phase map of the target pattern to generate a beam array. For example, by modulating the second laser through the spatial light modulator 31, it can be decomposed from one beam into multiple beams to form a beam array. By processing the sample with the beam array, multiple beams can act on different positions of the sample simultaneously, and the energy distribution of the modulated beam spot is uniform, thereby improving the laser direct writing efficiency. The surface exposure in the embodiments of the present application refers to processing the sample simultaneously through a beam array of multiple beams. The included angle between the second laser incident on the spatial light modulator 31 and the beam array reflected by the spatial light modulator 31 can be 15°.

[0030] The scanning direct writing module 4 can include a galvanometer 41 and a three-axis displacement stage 42. The galvanometer 41 can adjust the spot position of the beam array, and the sample can be placed on the three-axis displacement stage 42. Through the scanning direct writing module 4, the beam array can be controlled to perform laser direct writing on the sample, thereby transferring the target pattern to the sample. The sample can include a substrate.

[0031] When using the surface exposure laser direct writing system, the laser output module 1 emits a first laser beam into the collimating and beam expanding module 2. The collimating and beam expanding module 2 expands the first laser beam to obtain a second laser beam and incident the second laser beam on the liquid crystal element of the spatial light modulator 31 in the spatial light modulation module 3. The spatial light modulator 31 can modulate the second laser beam by loading different holographic phase maps, splitting and shaping a single beam into a multi-focus light field beam array with arbitrarily adjustable quantity, spot shape, and spacing. The scanning direct writing module 4 irradiates the beam array at the interface between the precursor solution and the substrate material on the sample, inducing a local reduction reaction, generating the reduction of metal ions and depositing according to the laser path, thereby forming a target pattern at the multi-focus positions and obtaining the sample with the desired metal structure.

[0032] The surface exposure laser direct writing system provided by the embodiments of the present application outputs a first laser through the laser output module 1, and a collimating and beam expanding module 2 is arranged on the optical path of the first laser to expand the first laser beam to obtain a second laser beam; the second laser beam is modulated by the spatial light modulator 31, and a single beam can be split into a beam array including multiple beams, and the sample can be processed simultaneously through the beam array of multiple beams, improving the laser direct writing efficiency; the spatial light modulation module 3 can also change the beam distribution and shape of the second laser beam according to the holographic phase map of the target pattern to achieve flexible processing of the sample.

[0033] In some embodiments, the surface exposure laser direct writing system further includes an imaging module 5; The imaging module 5 is disposed between the spatial light modulation module 3 and the scanning direct writing module 4 and is configured to maintain the phase of the beam array.

[0034] The imaging module 5 includes a first lens 51 and a second lens 52; A first distance is provided between the first lens 51 and the spatial light modulation module 3, and a second distance is provided between the first lens 51 and the second lens 52; The first lens 51 and the second lens 52 have the same focal length, the first distance is equal to the focal length, and the second distance is equal to twice the focal length.

[0035] Specifically, the imaging module 5 is configured to maintain the phase of the beam array so as to achieve accurate laser direct writing; Figure 2 This is the second schematic flow diagram of the surface exposure laser direct writing system provided by the embodiments of the present application. Figure 2 Some reflectors 6 are provided between the various modules of the surface exposure laser direct writing system, and the lines between the various structures refer to the optical paths. As Figure 2 shown, the imaging module 5 includes a first lens 51 and a second lens 52. The first lens 51 and the second lens 52 are on the optical path between the spatial light modulation module 3 and the scanning direct writing module 4, and they can jointly form a 4f system.

[0036] The 4f system sequentially includes an object plane, a first lens 51, a frequency spectrum plane, a first lens 51, and an image plane.

[0037] Among them, the object plane may refer to the spatial light modulation module 3, the frequency spectrum plane may refer to the junction of the first lens 51 and the second lens 52, and the image plane may refer to the scanning direct writing module 4. The first lens 51 and the second lens 52 have the same focal length of f. A first distance f is provided between the first lens 51 and the spatial light modulation module 3, and a second distance 2f is provided between the first lens 51 and the second lens 52. The total length of the 4f system is 4f. Lenses can be selected according to the actual scenario. For example, lenses with a focal length of 40 cm can be selected as the first lens 51 and the second lens 52. The 4f system can perform two Fourier transforms between plane to plane to maintain the phase of the beam array.

[0038] When the light output port position of the laser in the laser output module 1 is too low, it is necessary to raise the optical path to a suitable height. One or more reflectors 6 can be provided between the laser output module 1 and the collimating and beam expanding module 2 to form a climbing frame, and the height of the optical path can be adjusted through the climbing frame. When the beam energy is too strong, an attenuator 7 can be provided on the optical path to attenuate the beam energy.

[0039] The surface exposure laser direct writing system provided by the embodiment of the present application maintains the phase of the beam array through the imaging module 5, improving the accuracy of surface exposure laser direct writing.

[0040] In some embodiments, the scanning direct writing module 4 includes a galvanometer 41, and the galvanometer 41 is used to adjust the spot position of the beam array so that the spot moves based on a preset path to form the target pattern on the sample.

[0041] Specifically, the preset path is the moving path of the beam array set according to the target pattern. The galvanometer 41 can quickly change the direction of the laser beam in the beam array. By controlling the rotation angle of the galvanometer 41, the focus of the laser beam can be quickly positioned on the processing plane of the sample, so that the spot moves based on the preset path to form the required target pattern on the sample.

[0042] The surface exposure laser direct writing system provided by the embodiment of the present application improves the laser direct writing efficiency of the target pattern on the sample by quickly adjusting the spot position of the beam array through the galvanometer 41.

[0043] The surface exposure laser direct writing method provided by the embodiment of the present application will be described below. The surface exposure laser direct writing method described below can be mutually referred to with the surface exposure laser direct writing system described above.

[0044] Figure 3 It is a schematic flowchart of the surface exposure laser direct writing method provided by the embodiment of the present application. The surface exposure laser direct writing method provided by the embodiment of the present application is applied to a surface exposure laser direct writing system. The surface exposure laser direct writing system includes a laser output module 1, a collimating and beam expanding module 2, a spatial light modulation module 3, and a scanning direct writing module 4, as Figure 3 shown. The method includes step 310, step 320, step 330, and step 340. The steps of this method process are only a possible implementation manner of the present application.

[0045] Step 310: Output a first laser based on the laser output module 1; Step 320: Expand the original diameter of the spot of the first laser to a preset diameter based on the collimating and beam expanding module 2 to obtain a second laser; Step 330: Modulate the second laser based on the spatial light modulation module 3 to obtain a beam array corresponding to the holographic phase diagram of the target pattern. The beam array includes a plurality of beams; Step 340: Control the beam array to perform laser direct writing on the sample based on the scanning direct writing module 4 to transfer the target pattern to the sample.

[0046] Specifically, the preset diameter is determined based on the liquid crystal surface size of the spatial light modulation module 3.

[0047] The laser output module 1 projects a first laser beam onto the collimating and beam expanding module 2. The collimating and beam expanding module 2 expands the first laser beam to obtain a second laser beam and projects the second laser beam onto the liquid crystal element of the spatial light modulator 31 of the spatial light modulation module 3. By loading different holographic phase maps, the spatial light modulator 31 can modulate the second laser beam, splitting and shaping a beam of light into a multi-focus light field construction beam array with arbitrarily adjustable quantity, spot shape, and spacing. The scanning direct writing module 4 irradiates the beam array on the interface between the precursor solution and the substrate material of the sample, inducing a local reduction reaction, generating the reduction of metal ions and depositing according to the laser path, thereby forming a target pattern at the multi-focus positions and obtaining a sample with the desired metal structure.

[0048] It should be noted here that the surface exposure laser direct writing method provided by the embodiments of the present application can be implemented by the surface exposure laser direct writing system embodiments described above and can achieve the same technical effects. Therefore, the same parts and beneficial effects as those in the system embodiments will not be specifically described in this embodiment.

[0049] In some embodiments, the holographic phase map is obtained after performing a fast Fourier transform iteration on the target pattern; the holographic phase map includes the intensity and phase of the laser.

[0050] Specifically, intensity refers to the square of the amplitude of the laser, which determines the energy of the laser. In the holographic phase map, the intensity information is used to control the light intensity of each beam.

[0051] Phase describes the vibration state of the laser in space and time. The phase information is used to control the propagation direction and interference effect of the laser.

[0052] The holographic phase map of the embodiments of the present application includes the intensity and phase of the laser. The distribution range of the phase of the holographic phase map is from 0 to 2π, that is, the phase value of each pixel can vary between 0 and 2π to achieve different light field distributions.

[0053] The holographic phase map can be obtained after performing computational iteration on the target pattern based on the algorithm of the Fast Fourier Transform (FFT). In the process of obtaining the holographic phase map, algorithms such as the Gerchberg-Saxton (GS) algorithm, the Optimal Rotation Angle (ORA) algorithm, and the weighted GS algorithm may be involved.

[0054] The surface exposure laser direct writing method provided by the embodiments of the present application is through...

[0055] Figure 4The pattern formed on the sample surface by the surface exposure laser direct writing method provided in the embodiments of the present application is as follows Figure 4 As shown, code can be written using Matlab to obtain a 1×2 dot matrix. Read the target pattern in the Generalized Synthesis and Weighting (GSW) algorithm program, and then set the number of iterations, for example, 100 times. Based on this number of iterations, start calculating the holographic phase diagram of the target pattern.

[0056] After obtaining the computer-generated holography (CGH) diagram of the target pattern, that is, the holographic phase diagram, load it into the application program of the spatial light modulator 31 of the spatial light modulation module 3, and adjust the Fresnel lens to eliminate the influence of the zero-order light.

[0057] The precursor solution can contain metal ions such as Au, Ag, Cu, and Ni and a solvent. The prepared precursor solution can be spin-coated on the sample surface to form a uniform film. A femtosecond laser 11 with a wavelength of 515 nm, a pulse width of 800 fs, and a repetition frequency of 600 kHz is used to reduce copper ion ink to directly write a copper metal pattern, with a laser power of 2.25 W and a scanning speed of 200 mm / s. After processing, the excess metal ion film is rinsed off with deionized water and ethanol respectively, and dried with compressed air.

[0058] A circular pattern is formed on the sample surface by the surface exposure laser direct writing method provided in the embodiments of the present application.

[0059] It should be noted that each embodiment of the present application can be freely combined, the order can be swapped, or each can be executed alone, and does not need to rely on or depend on a fixed execution order.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A surface exposure laser direct writing system, characterized in that, Comprising: A laser output module for outputting a first laser; A collimating and beam expanding module disposed on the optical path of the first laser for expanding the original spot diameter of the first laser to a preset diameter to obtain a second laser; A spatial light modulation module disposed on the optical path of the second laser for modulating the second laser to obtain a beam array corresponding to the holographic phase map of the target pattern, the beam array including a plurality of beams; A scanning direct writing module disposed on the optical path of the beam array for performing laser direct writing on a sample based on the beam array to transfer the target pattern onto the sample.

2. The surface exposure laser direct writing system according to claim 1, wherein It further includes an imaging module; The imaging module is disposed between the spatial light modulation module and the scanning direct writing module for maintaining the phase of the beam array.

3. The surface exposure laser direct writing system according to claim 2, characterized in that, The imaging module includes a first lens and a second lens; There is a first distance between the first lens and the spatial light modulation module, and a second distance between the first lens and the second lens; The first lens and the second lens have the same focal length, the first distance is equal to the focal length, and the second distance is equal to twice the focal length.

4. The surface exposure laser direct writing system according to claim 1, wherein The scanning direct writing module includes a galvanometer, and the galvanometer is used to adjust the spot position of the beam array so that the spot moves based on a preset path to form the target pattern on the sample.

5. The surface exposure laser direct writing system according to claim 1, characterized in that, The laser output module includes a femtosecond laser, and the femtosecond laser is used to generate the first laser.

6. The surface exposure laser direct writing system according to claim 1, wherein The spatial light modulation module includes an amplitude-type and / or phase-type spatial light modulator.

7. A surface exposure laser direct writing method, characterized in that, Applied to a surface exposure laser direct writing system, the surface exposure laser direct writing system includes a laser output module, a collimating and beam expanding module, a spatial light modulation module, and a scanning direct writing module; the method includes: Outputting a first laser based on the laser output module; Expanding the original spot diameter of the first laser to a preset diameter based on the collimating and beam expanding module to obtain a second laser; Modulating the second laser based on the spatial light modulation module to obtain a beam array corresponding to the holographic phase map of the target pattern, the beam array including a plurality of beams; Controlling the beam array to perform laser direct writing on a sample based on the scanning direct writing module to transfer the target pattern onto the sample.

8. The surface exposure laser direct writing method according to claim 7, wherein The holographic phase map is obtained after performing fast Fourier transform iteration on the target pattern.

9. The surface exposure laser direct writing method according to claim 7, characterized in that The holographic phase map includes the intensity and phase of the laser.

10. The surface exposure laser direct writing method according to claim 7, characterized in that, The preset diameter is determined based on the liquid crystal surface size of the spatial light modulation module.

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