Wavelength specificity regulation and control device and preparation method thereof, and laser direct writing photoetching system using wavelength specificity regulation and control device

Abstract

The wavelength specificity regulation and control device comprises a fine tuning structure and an optical fiber, the fine tuning structure is a rectangular square block, the position of the end face of the optical fiber is a half area which shields a fiber core, the thickness of the fine tuning structure meets the generated optical path difference, and a 2 pi phase difference is generated at the wavelength position of excitation light. And a pi phase difference is generated at the suppression light wavelength. According to the preparation method, one end of the optical fiber is immersed in photoresist, and development is carried out after the fine tuning structure is inscribed through the two-photon inscribing module. The wavelength specificity regulation and control device does not modulate the exciting light, keeps Gaussian beam transmission, modulates the suppression light, and modulates the shape of the suppression light into a required suppression light spot. The two light beams are simultaneously transmitted in the device, so that the problem of light beam alignment is avoided, the stability of a light path is improved, and the integration of the system is also improved by using the device.

Description

Technical Field

[0001] The present invention relates to the field of optical technology and optical micro-nano processing and manufacturing, and in particular to a wavelength-specific control device for laser direct writing lithography and a laser direct writing lithography system using the device. Background Art

[0002] Laser direct writing technology is a flexible photolithography technology that does not require a mask plate or a digital mask. It can directly expose photoresist on substrates such as silicon and obtain the desired pattern after development. Its flexible, fast and low-cost characteristics make it widely used in the field of micro-nano processing. However, due to the existence of optical diffraction limits, the feature size in traditional laser direct writing systems is limited to sub-micrometers. For this reason, laser direct writing technology is usually only used in low-precision manufacturing, and its many advantages cannot be fully utilized. Therefore, improving the resolution of laser direct writing has become a problem that researchers have always paid attention to.

[0003] Two-photon laser direct writing lithography technology using femtosecond lasers utilizes the nonlinear absorption effect of materials to improve the resolution of traditional laser direct writing lithography technology to a certain extent, raising the resolution to hundreds of nanometers, and can realize the processing of complex three-dimensional structures in space. Furthermore, with the idea of ​​stimulated emission depletion microscopy imaging technology, the application of edge light suppression technology further improves the resolution of two-photon laser direct writing lithography technology. In conventional two-photon lithography technology, the light focused inside the photoresist to stimulate the polymerization effect is usually called excitation light. In this technology, an additional laser beam is added, which is used to suppress the action area of ​​the excitation light and thus improve the resolution. It is called suppression light. In this technology, the excitation light is focused into a Gaussian spot by the objective lens, and the spot excites the photoresist to undergo a polymerization reaction. After the suppression light is focused, it becomes a hollow spot (or called a ring spot) that coincides with the Gaussian spot of the excitation light, and produces a light suppression effect at the edge of the excitation light. Using this method, the feature size of laser direct writing lithography technology can be increased to sub-50nm. Because of the use of two beams of light, this method is also called dual-beam writing.

[0004] In the dual-beam writing method with edge light suppression, the generation and control of the annular spot is the key to whether the method can achieve ultra-high precision.

[0005] Patent document CN114019765A discloses a common-path phase-modulated laser direct writing method and device based on edge light suppression, including an excitation light source, a suppression light source, a spatial light modulator, an objective lens, a computer and a direct writing method. The device partitions and multiplexes the spatial light modulator to simultaneously control the dual light beams based on edge light suppression. Patent document CN113189846A discloses a dual-path parallel super-resolution laser direct writing device based on light field control, including a direct writing laser, a suppression path laser, a collimator, an anti-drift system, an energy control module, a wavefront control module and a beam combining module. The device partitions and multiplexes the spatial light modulator and uses polarization characteristics to achieve dual-spot focusing. The device uses polarization splitting technology to achieve dual-channel writing, but it is difficult to achieve multi-channel writing based on this method, and its scalability is limited.

[0006] Both of the above methods use a spatial light modulator to generate a hollow light spot by modulating the vortex phase. The advantage of a spatial light modulator is that it can load any phase and flexibly modulate the shape and aberration of the light spot. However, since the excitation light and the suppression light cannot overlap on the spatial optical path, it is impossible to strictly align the suppression light and the excitation light. In addition, the spatial light modulator greatly increases the complexity of the optical path, increases the difficulty of debugging, and to a certain extent increases the cost of the equipment, which is not conducive to industrialization and large-scale application. Therefore, how to stably and quickly achieve coaxial specific regulation and multi-channel writing of dual beams is a key technical problem that needs to be solved urgently. Summary of the invention

[0007] The purpose of the present invention is to provide a wavelength-specific control device for laser direct writing lithography and a laser direct writing lithography system using the device. The wavelength-specific control device does not modulate the excitation light and maintains the transmission of the Gaussian beam; it modulates the suppression light and modulates its shape into a desired suppression light spot. Since the two light beams are transmitted simultaneously in the device, the problem of beam alignment is avoided and the stability of the optical path is increased.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A wavelength-specific control device for laser direct writing lithography includes a micro-modulation structure and an optical fiber. The micro-modulation structure is a rectangular block. The micro-modulation structure is located at the end face of the optical fiber and blocks half of the area of ​​the fiber core. The thickness of the micro-modulation structure satisfies the phase difference generated, generating a 2π phase difference at the wavelength of the excitation light and a π phase at the wavelength of the suppression light.

[0010] The formula for calculating the phase difference is:

[0011]

[0012] is the phase difference, n is the material refractive index, Δh is the thickness, λ is the wavelength,

[0013] The micro-modulation structure generates different phase differences for different wavelengths λ1 and λ2 with the same thickness.

[0014] After the excitation light passes through the wavelength-specific control device, it is not modulated and is circular, maintaining the Gaussian spot distribution; after the suppression light passes through the wavelength-specific control device, it is modulated into a symmetrical hollow shape. Since the two light beams are transmitted simultaneously in the device, the problem of beam alignment is avoided, the stability of the optical path is increased, and the use of the device also improves the integration of the system.

[0015] Furthermore, a wavelength-specific control device for laser direct writing lithography also includes a supporting structure and a micro-focusing structure. The supporting structure is a hollow structure and is placed on the end face of the optical fiber. The micro-modulation structure is located inside the supporting structure, and the micro-focusing structure is placed on the top of the supporting structure.

[0016] The top of the support structure is used to place a micro-focusing structure, which can be a lens for focusing the light beam. The micro-focusing structure provides a collection area larger than the core size, focusing the incident light beam on the core, thereby improving the collection efficiency of the optical fiber. The support structure is used to support the micro-focusing structure and provide an optimal working distance from the micro-focusing structure to the end face of the optical fiber.

[0017] A method for preparing a wavelength-specific control device for laser direct writing lithography comprises the following steps:

[0018] S1: drop-coat photoresist on the surface of the objective lens;

[0019] S2: Immerse one end of the optical fiber in photoresist and fix it on the two-photon writing module, aligning it with the center of the writing objective lens;

[0020] S3: Align and connect the other end of the optical fiber to the fiber laser, turn on the fiber laser, move the piezoelectric platform so that the light spot output by the fiber core observed by the objective lens is the smallest, and then turn off the fiber laser to complete the alignment;

[0021] S4: converting the micro-modulation structure into writing data through data processing, coordinate mapping and format conversion;

[0022] S5: Import the writing data into the control software, set the writing parameters, and execute the writing;

[0023] S6: After the writing is completed, the optical fiber is taken out and immersed in a propylene glycol monomethyl ether acetic acid solution, and then immersed in an isopropyl alcohol solution, and finally the optical fiber is placed in the air to dry.

[0024] Preferably, the photoresist comprises a mixture of at least one or more of dicyclopentenyl methacrylate, o-phenylphenol polyoxyethylene ether acrylate and 7-diethylamino-3-thenoyl coumarin.

[0025] The system uses a beam combiner to combine the beams, and can realize super-resolution laser direct writing by combining a wavelength-specific control device and the use of excitation light and suppression light. Preferably, the photoinitiator is a mixture of at least one or more of 7-diethylamino-3-thenoyl coumarin, 2-isopropylthioxanthone, 4-isopropylthioxanthone, tetraethyl Michler's ketone, and Irgacure 369.

[0026] Preferably, the two-photon engraving module includes a femtosecond laser, an acousto-optic modulator, a scanning galvanometer, a piezoelectric platform, a displacement platform and an objective lens, wherein the femtosecond laser provides a direct-writing laser, the acousto-optic modulator is used to control the power of the direct-writing laser, and the graphics of the engraving structure are realized by modulating the rotation direction of the scanning galvanometer. The optical fiber is placed on the displacement platform and moves horizontally, and the piezoelectric platform moves vertically to focus the laser on the surface of the optical fiber through the objective lens.

[0027] A laser direct writing lithography system using a wavelength-specific control device comprises an excitation light module for inducing a photopolymerization effect of a photoresist, an inhibition light module for inhibiting a photopolymerization reaction of the photoresist, a beam combining module, a direct writing module and a monitoring module. The beam combining module comprises a beam combining mirror, an optical fiber coupler and a wavelength-specific control device. The excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined by the beam combining mirror and the optical fiber coupler. The combined light passes through the wavelength-specific control device so that the excitation light is not modulated and the Gaussian spot distribution is maintained, so that the inhibition light is modulated into a symmetrical hollow shape. The modulated combined light passes through the direct writing module to write the photoresist on the stage. The monitoring module monitors the laser direct writing situation.

[0028] The system uses a beam combiner to combine the beams, and combined with wavelength-specific control devices and the use of excitation light and suppression light, it can achieve super-resolution laser direct writing.

[0029] A laser direct writing lithography system using a wavelength specific control device comprises an excitation light module for inducing a photopolymerization effect of a photoresist, an inhibition light module for inhibiting a photopolymerization reaction of the photoresist, a beam combining module and a direct writing module, wherein the beam combining module comprises a polarization beam combiner and an optical fiber coupler, and the direct writing module comprises a wavelength specific control device and an object stage, the excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined by the polarization beam combiner and the optical fiber coupler, the combined light passes through the wavelength specific control device so that the excitation light is not modulated and the Gaussian spot distribution is maintained, so that the inhibition light is modulated into a symmetrical hollow shape, and the modulated combined light passes through the direct writing module to write the photoresist on the object stage.

[0030] The system uses a polarization beam combiner to combine the beams, and combines wavelength-specific control devices with the use of excitation light and suppression light to achieve super-resolution laser direct writing.

[0031] A laser direct-writing lithography system using a wavelength-specific control device comprises an excitation light module for inducing a photopolymerization effect of a photoresist, an inhibition light module for inhibiting a photopolymerization reaction of the photoresist, a beam combining module and a direct-writing module. The multiple excitation light modules, inhibition light modules and beam combining modules are arranged in parallel to form a parallel light beam output. The direct-writing module comprises a wavelength-specific control device and an object stage. The excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined by a polarization beam combiner and an optical fiber coupler. The combined light passes through the wavelength-specific control device so that the excitation light is not modulated and the Gaussian spot distribution is maintained, so that the inhibition light is modulated into a symmetrical hollow shape. The modulated combined light passes through the direct-writing module to write the photoresist on the object stage.

[0032] The system uses multiple excitation light modules, suppression light modules and beam combining modules to achieve multi-beam parallel super-resolution laser direct writing.

[0033] A laser direct writing lithography system using a wavelength specific control device comprises an excitation light module for inducing a photopolymerization effect of a photoresist, an inhibition light module for inhibiting a photopolymerization reaction of the photoresist, a beam combining module and a direct writing module. The direct writing module comprises a microstructure array and a wavelength specific control array. The microstructure array is formed by closely arranging microstructures into an array structure, and the array size is consistent with the output spot diameter of the beam combining module. The microstructure comprises a microlens, a supporting structure and a micro coupling structure. The microlens is used to focus an incident light beam to a core position of an optical fiber, and the size of the microlens is consistent with the size of the optical fiber. The supporting structure is used to support the microlens. The micro coupling structure is placed at the input end face of the optical fiber to increase the collection angle of the optical fiber. The wavelength specific control array is formed by closely arranging wavelength specific control devices into an array structure. The excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined by the beam combining module. The combined light passes through the microstructure array and the wavelength specific control array, so that the excitation light is not modulated, the Gaussian spot distribution is maintained, and the inhibition light is modulated into a symmetrical hollow shape. The modulated combined light passes through the direct writing module to write the photoresist on a stage.

[0034] The system achieves high-efficiency coupling by preparing microstructures on the end face of the optical fiber, and combines multiple optical fibers into an array to achieve multi-beam parallel output, which is characterized by integration and high efficiency.

[0035] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0036] The wavelength-specific control device does not modulate the excitation light, maintains Gaussian beam transmission, and modulates the suppression light, modulating its shape into the required suppression spot. Since the two beams are transmitted simultaneously in the device, the beam alignment problem is avoided, the stability of the optical path is increased, and the use of the device also improves the integration of the system.

[0037] The two-photon direct writing method is used to manufacture micro-modulation structures on the end face of the optical fiber to form a wavelength-specific control device. The wavelength-specific modulation device is combined with the excitation light module, the suppression light module, etc. to form a laser direct writing system. The excitation light and the suppression light are modulated separately by the wavelength-specific modulation device to generate light spots of different shapes, which are focused on the sample surface and superimposed by the objective lens to achieve super-resolution laser direct writing. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings.

[0039] Figure 1 Schematic diagram of the two-photon direct writing module in Example 1.

[0040] Figure 2 Schematic diagram of the wavelength-specific control device I in Example 1.

[0041] Figure 3 Schematic diagram of the laser direct writing lithography system in Example 2.

[0042] Figure 4 This is the light spot pattern formed by the camera on the stage photoresist after the excitation light passes through the wavelength-specific control device I in Example 2.

[0043] Figure 5 This is the light spot pattern formed on the stage photoresist by the camera after suppressing the light from passing through the wavelength-specific control device I in Example 2.

[0044] Figure 6 This is the light spot pattern formed by the camera on the stage photoresist after the excitation light and the inhibition light pass through the wavelength-specific control device I in Example 2.

[0045] Figure 7 Schematic diagram of the wavelength-specific control device II in Example 3.

[0046] Figure 8 Schematic diagram of the laser direct writing lithography system in Example 3.

[0047] Fig. 9 Schematic diagram of the laser direct writing lithography system in Example 4.

[0048] Fig.10 Schematic diagram of the laser direct writing lithography system in Example 5.

[0049] Fig.11 Schematic diagram of the microstructure array and wavelength-specific control array in Example 5.

[0050] Fig.12 This is the light spot pattern formed by the camera on the stage photoresist after the excitation light passes through the microstructure array and the wavelength-specific control array in Example 5.

[0051] Fig.13 This is the light spot diagram formed on the stage photoresist by the camera after suppressing the light from passing through the microstructure array and the wavelength-specific control array in Example 5.

[0052] Fig.14 The spot pattern formed on the stage photoresist by the camera after the excitation light and the suppression light pass through the microstructure array and the wavelength-specific control array. DETAILED DESCRIPTION

[0053] Example 1

[0054] A method for preparing a wavelength-specific control device for laser direct writing lithography comprises the following steps:

[0055] S1: drop-coating photoresist on the surface of the objective lens 22.

[0056] In this embodiment, dicyclopentenyl methacrylate is used as the photoresist, and 7-diethylamino-3-thenoyl coumarin is used as the photoinitiator. The photoinitiator accounts for 0.1-10% of the total mass fraction of the photoresist.

[0057] In some other embodiments, the photoresist can be formed by mixing at least one or more of o-phenylphenol polyoxyethylene ether acrylate and 7-diethylamino-3-thenoyl coumarin, and the photoinitiator can be formed by mixing at least one or more of 7-diethylamino-3-thenoyl coumarin, 2-isopropylthioxanthone, 4-isopropylthioxanthone, tetraethyl Michler's ketone, and Irgacure 369.

[0058] S2: Pass one end of the optical fiber 2 through the positioning fixture 39, immerse it in the photoresist and fix it in the position as shown in FIG. Figure 1 The two-photon writing module shown is aligned with the center of the objective lens 22. The two-photon direct writing module mainly includes a femtosecond laser 40, an acousto-optic modulator 41, a scanning galvanometer 42, an objective lens 22, a piezoelectric platform 43, a displacement platform 44 and an objective lens 22, wherein the femtosecond laser 40 provides direct writing laser, the acousto-optic modulator 41 is used to control the power of the direct writing laser, and different morphologies of the written structure are achieved by modulating the rotation direction of the scanning galvanometer 42. The model of the objective lens 22 is Olympus UPLXAPO40XO.

[0059] S3: Align and connect one end of the optical fiber 2 immersed in the photoresist with the femtosecond laser 40, and turn on the femtosecond laser 40. Move the piezoelectric platform 43 so that the light spot output from the core of the optical fiber 2 observed by the objective lens 22 is the smallest, and then turn off the femtosecond laser 40 to complete the alignment.

[0060] S4: Use data processing software to convert the micro-modulation structure into writing data. The micro-modulation structure file can be in one of the formats of STL, JPEG, TIFF, PNG, GDS, etc. The data is the shape and size of the micro-modulation structure.

[0061] S5: Import the writing data into the control software, set the writing parameters, and execute the writing. In this embodiment, the writing parameters include: the writing speed is 100 mm / s, and the writing power is 25 mW.

[0062] S6: After writing is completed, the optical fiber 2 is taken out from the positioning fixture 39 and placed in a reagent for development. The development process includes: placing the optical fiber 2 in a propylene glycol monomethyl ether acetic acid solution for 9 minutes, then soaking it in an isopropyl alcohol solution for 2 minutes, and finally placing the optical fiber 2 in the air to dry.

[0063] The structure of the prepared wavelength-specific control device I is as follows: Figure 2 As shown, it includes a micro-modulation structure 1 and an optical fiber 2. The micro-modulation structure 1 is a rectangular block. The position of the optical fiber end face 4 is to cover half of the area of ​​the fiber core 3. The thickness of the micro-modulation structure 1 satisfies the optical path difference generated, generating a 2π phase difference at the excitation light wavelength and a π phase difference at the suppression light wavelength.

[0064] The formula for calculating the phase difference is:

[0065]

[0066] is the phase difference, n is the refractive index of the material, Δh is the thickness, and λ is the wavelength.

[0067] In this embodiment, the wavelength of the excitation light is 780 nm, and the wavelength of the suppression light is 532 nm. According to the π phase difference and the material refractive index of the photoresist, the thickness of the micro-modulation structure 1 can be calculated.

[0068] Example 2

[0069] like Figure 2 A laser direct writing lithography system using the wavelength specific control device prepared in Example 1 is shown, comprising an excitation light module for inducing photopolymerization of the photoresist, an inhibition light module for inhibiting photopolymerization of the photoresist, a beam combining module, a direct writing module and a monitoring module.

[0070] Excitation light module includes

[0071] The excitation light laser 7 is used to generate excitation light.

[0072] The first lens 8 and the second lens 9 are used to shrink the excitation light to a spot diameter required by the first acousto-optic modulator 10 .

[0073] The first acousto-optic modulator 10 is used to control the switch and intensity of the excitation light.

[0074] The first reflector 11 is used to deflect the excitation light.

[0075] Suppression optical modules include

[0076] The suppression light laser 12 is used to generate suppression light.

[0077] The third lens 13 and the fourth lens 14 are used to shrink the suppression light to the spot diameter required by the second AOM.

[0078] The second acousto-optic modulator 15 is used to control the switch and intensity of the suppression light.

[0079] The beam combining module includes

[0080] The excitation light and the suppression light are combined by the beam combining mirror 16 .

[0081] The second reflecting mirror 17 is used for deflecting the combined light beam.

[0082] The optical fiber coupler 18 couples the light beam into the optical fiber 2.

[0083] The wavelength-specific control device I19 modulates the incident light beam. After the excitation light passes through the wavelength-specific control device I19, it is not modulated and is circular, maintaining the Gaussian spot distribution. After the suppression light passes through the wavelength-specific control device I19, it is modulated into a symmetrical hollow shape.

[0084] Direct write module includes

[0085] The fifth lens 20 and the sixth lens 21 collimate and expand the output light beam of the wavelength-specific control device and image it to the entrance pupil of the objective lens 22, so that the output light beam diameter is consistent with the entrance pupil size of the objective lens 22, thereby achieving super-resolution writing.

[0086] The objective lens 22 focuses the light beam onto the sample surface.

[0087] The sample is placed on the stage 23 , and the movement of the sample is controlled by the stage 23 .

[0088] The monitoring module includes:

[0089] The first beam splitter 24 deflects the light beam emitted from the beam combining module.

[0090] The seventh lens 25 focuses the light reflected from the first beam splitter 24 .

[0091] The second beam splitter 26 , the light emitted by the illumination light source 38 is reflected by the second beam splitter 26 .

[0092] Camera 27 monitors the laser direct writing status.

[0093] Figure 4 It shows the circular spot formed on the photoresist on the stage 23 after the excitation light passes through the wavelength-specific control device I19.

[0094] Figure 5 It shows the hollow-shaped light spot formed on the photoresist of the stage 23 after suppressing the light from passing through the wavelength-specific control device I19.

[0095] Figure 6 The elongated light spot is formed on the photoresist on the stage 23 after the excitation light and the suppression light pass through the wavelength-specific control device I19 together.

[0096] Example 3

[0097] A support structure 5 and a micro-focusing structure 6 are added to the wavelength-specific control device I19 prepared in Example 1 to prepare a wavelength-specific control device II28. The support structure 5 is a hollow structure and is placed on the optical fiber end face 4, the micro-modulation structure 1 is located inside the support structure 5, and the micro-focusing structure 6 is placed on the top of the support structure 5. Figure 7 shown.

[0098] like Figure 8 A laser direct writing lithography system using the above-mentioned wavelength specific control device II28 is shown, including an excitation light module for inducing photopolymerization effect of photoresist, an inhibition light module for inhibiting photopolymerization reaction of photoresist, a beam combining module and a direct writing module.

[0099] Excitation light module includes

[0100] The excitation light laser 7 is used to generate excitation light.

[0101] The first lens 8 and the second lens 9 are used to shrink the excitation light to a spot diameter required by the first acousto-optic modulator 10 .

[0102] The first acousto-optic modulator 10 is used to control the switch and intensity of the excitation light.

[0103] The first reflector 11 is used to deflect the excitation light.

[0104] The half-wave plate 29 is used to adjust the linear polarization direction of the excitation light.

[0105] Suppression optical modules include

[0106] The suppression light laser 12 is used to generate suppression light.

[0107] The third lens 13 and the fourth lens 14 are used to shrink the suppressed light to a spot diameter required by the second AOM 15 .

[0108] The second acousto-optic modulator 15 is used to control the switch and intensity of the suppression light.

[0109] The beam combining module includes

[0110] Polarization beam combiner 30 , the excitation light and the suppression light are combined through the polarization beam combiner 30 .

[0111] The optical fiber coupler 18 couples the light beam into the optical fiber 2.

[0112] Direct write module includes

[0113] The wavelength-specific control device II28 modulates the incident light beam. After the excitation light passes through the wavelength-specific control device II28, it is not modulated and is circular, maintaining the Gaussian spot distribution. After the suppression light passes through the wavelength-specific control device II28, it is modulated into a symmetrical hollow shape.

[0114] The stage 23, the photoresist is dripped onto the sample surface, and the wavelength-specific control device II28 is directly immersed in the photoresist to realize laser direct writing.

[0115] Example 4

[0116] like Fig. 9 As shown, a laser direct writing lithography system using a wavelength specific control device II28 includes an excitation light module for inducing photopolymerization of the photoresist, an inhibition light module for inhibiting photopolymerization of the photoresist, a beam combining module and a direct writing module.

[0117] The excitation light module includes |

[0118] The excitation light laser 7 is used to generate excitation light.

[0119] The first fiber acousto-optic modulator 31 is used to control the switch and intensity of the excitation light.

[0120] Suppression optical modules include

[0121] The suppression light laser 12 is used to generate suppression light.

[0122] The second fiber acousto-optic modulator 32 is used to control the switch and intensity of the excitation light.

[0123] The beam combining module includes

[0124] The beam combiner 33 is used to combine the input excitation light fiber 2 and the suppression light fiber 2 into a single optical fiber 2 for output.

[0125] A plurality of excitation light modules, suppression light modules and beam combining modules are arranged in parallel to form parallel light beam output.

[0126] The direct writing module includes a wavelength-specific control device II28, which modulates the incident light beam. After the excitation light passes through the wavelength-specific control device II28, it is not modulated and is circular, maintaining the Gaussian spot distribution. After the suppression light passes through the wavelength-specific control device II28, it is modulated into a symmetrical hollow shape.

[0127] The sample is placed on the stage 23, photoresist is dripped on the surface of the sample, and the wavelength-specific control device II28 is directly immersed in the photoresist to realize laser direct writing.

[0128] Example 5

[0129] like Fig.10 As shown, a laser direct writing lithography system using a wavelength specific control device II28 includes an excitation light module for inducing photopolymerization of the photoresist, an inhibition light module for inhibiting photopolymerization of the photoresist, a beam combining module and a direct writing module.

[0130] Excitation light module includes

[0131] The excitation light laser 7 is used to generate excitation light.

[0132] The first lens 8 and the second lens 9 are used to shrink the excitation light to a spot diameter required by the first acousto-optic modulator 10 .

[0133] The first acousto-optic modulator 10 is used to control the switch and intensity of the excitation light.

[0134] The first reflector 11 is used to deflect the excitation light.

[0135] Suppression optical modules include

[0136] The suppression light laser 12 is used to generate suppression light.

[0137] The third lens 13 and the fourth lens 14 are used to shrink the suppression light to a spot diameter required by the second acousto-optic modulator 15;

[0138] The second acousto-optic modulator 15 is used to control the switch and intensity of the suppression light.

[0139] The beam combining module includes

[0140] In the beam combiner 33 , the excitation light and the suppression light are combined by the beam combiner 16 .

[0141] Direct write module includes

[0142] like Fig.11The microstructure array 34 shown is at one end of the optical fiber 2, and is composed of microstructures closely arranged into an array structure. The array size is consistent with the output spot diameter of the beam combining module, wherein the microstructure includes a microlens 35, a support structure 5 and a microcoupling structure 36. The microlens 35 is used to focus the incident light beam to the core 3 position of the optical fiber 2. The size of the microlens 35 is consistent with the size of the optical fiber 2. The support structure 5 is used to support the microlens 35. The microcoupling structure 36 is placed at the input end face of the optical fiber 2 to increase the collection angle of the optical fiber 2.

[0143] like Fig.11 The wavelength-specific control array 37 shown is at the other end of the optical fiber 2, and is composed of wavelength-specific control devices II28 tightly arranged into an array structure.

[0144] The sample is placed on the stage 23 , and the movement of the sample is controlled by the stage 23 .

[0145] Fig.12 The excitation light is shown Figure 4 It shows the circular spot array formed on the photoresist of the stage 23 after the excitation light passes through the wavelength-specific control device I19.

[0146] Fig.13 It shows an array of hollow-shaped spots formed on the photoresist of the stage 23 after suppressing light from passing through the wavelength-specific control device I19.

[0147] Fig.14 An array of elongated light spots is formed on the photoresist on the stage 23 after the excitation light and the suppression light pass through the wavelength-specific control device I19 together.

[0148] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. A wavelength-specific control device for laser direct writing lithography, characterized in that: It includes a micro-modulation structure and an optical fiber, wherein the micro-modulation structure is a rectangular block, the micro-modulation structure is located at the end face of the optical fiber and covers half of the area of ​​the fiber core, and the thickness of the micro-modulation structure meets the phase difference generated. A 2π phase difference is generated at the excitation light wavelength, and a π phase is generated at the suppression light wavelength. The calculation formula of the phase difference is: is the phase difference, n is the material refractive index, Δh is the thickness, λ is the wavelength, The micro-modulation structure generates different phase differences for different wavelengths λ1 and λ2 with the same thickness.

2. A wavelength-specific control device for laser direct writing lithography according to claim 1, characterized in that: It also includes a supporting structure and a micro-focusing structure. The supporting structure is a hollow structure and is placed on the optical fiber end face. The micro-modulation structure is located inside the supporting structure. The micro-focusing structure is placed on the top of the supporting structure.

3. A method for preparing a wavelength-specific control device for laser direct writing lithography as claimed in claim 1, characterized in that: The steps include: S1: drop-coat photoresist on the surface of the objective lens; S2: Immerse one end of the optical fiber in photoresist and align it with the fiber laser, turn on the fiber laser, move the piezoelectric platform so that the light spot output by the fiber core observed by the objective lens is the smallest, and then turn off the fiber laser to complete the alignment; S3: converting the micro-modulation structure into writing data; S4: Import the writing data into the control software, set the writing parameters, and execute the writing; S5: After the writing is completed, the optical fiber is taken out and immersed in a propylene glycol monomethyl ether acetic acid solution, and then immersed in an isopropyl alcohol solution, and finally the optical fiber is placed in the air to dry.

4. The method for preparing a wavelength-specific control device for laser direct writing lithography according to claim 3, characterized in that: The photoresist includes at least one or more of dicyclopentenyl methacrylate, o-phenylphenol polyoxyethylene ether acrylate and 7-diethylamino-3-thenoyl coumarin.

5. The method for preparing a wavelength-specific control device for laser direct writing lithography according to claim 3, characterized in that: The photoinitiator is a mixture of at least one or more of 7-diethylamino-3-thenoylcoumarin, 2-isopropylthioxanthone, 4-isopropylthioxanthone, tetraethyl Michler's ketone and Irgacure 369.

6. The method for preparing a wavelength-specific control device for laser direct writing lithography according to claim 2, characterized in that: The two-photon engraving module includes a femtosecond laser, an acousto-optic modulator, a scanning galvanometer, an objective lens, a piezoelectric platform and a displacement platform. The femtosecond laser provides direct writing laser, the acousto-optic modulator is used to control the power of the direct writing laser, and the graphics of the engraving structure are realized by modulating the rotation direction of the scanning galvanometer. The sample is placed on the displacement platform and moved horizontally, and the piezoelectric platform moves vertically to focus the laser on the sample surface through the objective lens.

7. A laser direct writing lithography system using the wavelength specific control device as claimed in claim 1, characterized in that: It includes an excitation light module for inducing photopolymerization effect of photoresist, an inhibition light module for inhibiting photopolymerization reaction of photoresist, a beam combining module, a direct writing module and a monitoring module. The beam combining module includes a beam combining mirror, an optical fiber coupler and the wavelength-specific control device. The excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined through the beam combining mirror and the optical fiber coupler. The combined light passes through the wavelength-specific control device so that the excitation light is not modulated and the Gaussian spot distribution is maintained, so that the inhibition light is modulated into a symmetrical hollow shape. The modulated combined light passes through the direct writing module to write photoresist on the stage, and the monitoring module monitors the laser direct writing situation.

8. A laser direct writing lithography system using the wavelength specific control device as claimed in claim 2, characterized in that: It includes an excitation light module for inducing photopolymerization effect of photoresist, an inhibition light module for inhibiting photopolymerization reaction of photoresist, a beam combining module and a direct writing module, the beam combining module includes a polarization beam combiner and an optical fiber coupler, the direct writing module includes a wavelength-specific control device and an object stage, the excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined through the polarization beam combiner and the optical fiber coupler, the combined light passes through the wavelength-specific control device, so that the excitation light is not modulated, the Gaussian spot distribution is maintained, and the inhibition light is modulated into a symmetrical hollow shape, and the modulated combined light passes through the direct writing module to write the photoresist on the object stage.

9. A laser direct writing lithography system using the wavelength specific control device as claimed in claim 2, characterized in that: It includes an excitation light module for inducing photopolymerization effect of photoresist, an inhibition light module for inhibiting photopolymerization reaction of photoresist, a beam combining module and a direct writing module. A plurality of the excitation light modules, the inhibition light modules and the beam combining modules are arranged in parallel to form a parallel light beam output. The direct writing module includes a wavelength-specific control device and an object stage. The excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined by the polarization beam combiner and the optical fiber coupler. The combined light passes through the wavelength-specific control device so that the excitation light is not modulated and the Gaussian spot distribution is maintained, so that the inhibition light is modulated into a symmetrical hollow shape. The modulated combined light passes through the direct writing module to write the photoresist on the object stage.

10. A laser direct writing lithography system using the wavelength specific control device as claimed in claim 2, characterized in that: The invention comprises an excitation light module for inducing photoresist to produce a photopolymerization effect, an inhibition light module for inhibiting the photoresist from producing a photopolymerization reaction, a beam combining module and a direct writing module. The direct writing module comprises a microstructure array at one end of the optical fiber and a wavelength-specific control array at the other end of the optical fiber. The microstructure array is closely arranged into an array structure, and the array size is consistent with the output spot diameter of the beam combining module. The microstructure comprises a microlens, a support structure and a micro coupling structure. The microlens is used to focus the incident light beam to the core position of the optical fiber. The size of the microlens is consistent with the size of the optical fiber. The support structure is consistent with the size of the optical fiber. The structure is used to support the microlens. The micro-coupling structure is placed at the input end face of the optical fiber to increase the collection angle of the optical fiber. The wavelength-specific control array is closely arranged into an array structure by the wavelength-specific control devices. The excitation light generated by the excitation light module and the inhibition light generated by the inhibition light module are combined by the beam combining module. The combined light passes through the microstructure array and the wavelength-specific control array, so that the excitation light is not modulated, the Gaussian spot distribution is maintained, and the inhibition light is modulated into a symmetrical hollow shape. The modulated combined light passes through the direct writing module to write photoresist on the stage.

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