Super-resolution maskless exposure device and method based on dual-color dual-step absorption effect

Abstract

The present invention discloses a super-resolution maskless exposure device and method based on a two-color two-step absorption effect. The present invention utilizes a digital micromirror device to realize the regulation of an independent laser point switch, and the regulation speed can reach kHz, laying the foundation for rapid processing. The present invention makes full use of the large-scale matrix pixels of the digital micromirror device to form a laser direct writing point array of more than one million points, which can quickly complete the writing of large-area complex structures. The present invention further focuses the smallest pixel unit in the digital micromirror device into a smaller point of action through a microlens array, and utilizes the two-color two-step absorption effect to achieve a high writing resolution that exceeds the diffraction limit. The present invention can quickly and specifically regulate the laser point array, and act on the material to realize the two-color two-step absorption effect, which can provide the necessary technical basis for the realization of a fast, high-precision maskless exposure system that can realize direct writing of large-area complex structures.

Description

Technical Field

[0001] The present invention belongs to the technical field of maskless lithography, and in particular relates to a super-resolution maskless exposure device and method based on a dual-color dual-step absorption effect. Background Art

[0002] Chips are typical representatives of modern high-tech products, and photolithography is the key core technology for manufacturing chips.

[0003] Photolithography refers to the process of patterning a designed pattern on a photosensitive substrate by exposure. The photolithography process mainly includes: substrate pretreatment, timed exposure, development, etching and other steps.

[0004] The mainstream of existing lithography technology is mask lithography and maskless lithography. For mask lithography, smaller feature size means expensive mask processing cost, and the characteristics of the mask determine the immutability of the mask, lack of versatility and flexibility. Because of the many limitations of the mask, maskless lithography has gradually appeared in everyone's sight and has become a hot research topic in the field of lithography. Laser direct writing technology is one of the fastest-growing maskless lithography technologies. It shrinks the energy beam to the micron and nanometer level, and then moves the substrate or energy beam to modify the photosensitive material at different positions on the substrate, thereby causing the difference in the dissolution of the exposed part and the unexposed part in the special developer, and then removes the patterned part.

[0005] Although similar maskless lithography technology has made great breakthroughs in improving lithography resolution and can achieve nanometer-level lithography resolution, it uses point scanning or line scanning for lithography, so when lithography large-size and large-area patterns, it requires a longer exposure time, is not suitable for large-area lithography, and has high requirements for the working environment and high cost. Therefore, the development of a simple, easy-to-use, efficient, low-cost, and flexible maskless lithography technology is an inevitable requirement for the further development of micro-nano device technology, the improvement of chip integration, and the acceleration of chip tape-out.

[0006] The surface projection lithography technology based on digital micromirror devices has attracted widespread attention from researchers due to its fast, low-cost and flexible lithography characteristics. Compared with traditional mask lithography, this method is flexible in design and only requires designing lithography patterns on a computer to generate a digital mask to replace the traditional mask. However, it is a daunting challenge to achieve high resolution and large production volume at the same time. The maskless lithography technology based on digital micromirror devices sacrifices high resolution to obtain high-efficiency surface projection lithography. How to balance high resolution and fast writing capabilities is the current challenge.

[0007] The use of the two-color two-step absorption effect can achieve a high writing resolution that exceeds the diffraction limit. For example, the invention application with the publication number CN114779591A discloses a super-resolution lithography method based on the two-color two-step absorption effect. The method is based on the spectral absorption characteristics of the ground state and triplet state of the benzil photoinitiator, and uses a laser beam with a wavelength in the ground state absorption range of the material and another laser beam with a wavelength in the triplet absorption range of the material to act on the material together. The two-color two-step absorption effect is achieved by controlling the energy of the two, and combined with the relative displacement control of the two, a writing line width less than the diffraction limit is obtained.

[0008] For another example, the invention application with the publication number CN115826364A discloses a high-throughput super-resolution nano-writing method and device based on the double-step two-photon effect, wherein an excitation light and a photosynthesis-promoting beam with a time delay are incident on a digital micromirror device, and then imaged onto a photoresist with a double-step two-photon effect coated on a substrate of a three-dimensional sample stage; the digital micromirror device is controlled according to the required writing structure to complete the exposure at the focal plane where the substrate is located, and the three-dimensional sample stage, as well as the delay of the excitation light and the promoting light are controlled at the same time, so that the delay is greater than the singlet excited state S1 to the multiplet state T1 of the photoresist molecule, thereby realizing the double-step two-photon effect and realizing the writing of any three-dimensional nanostructure; the excitation light and the promoting light are laser beams with the same wavelength and the same repetition frequency, and the pulse width of the excitation light is femtoseconds, and the pulse width of the promoting light is picoseconds or nanoseconds. However, the writing resolution and the structural thickness size still need to be further improved. Summary of the invention

[0009] The purpose of the present invention is to address the deficiencies of the prior art and provide a super-resolution maskless exposure device and method based on a two-color two-step absorption effect, which can perform fast, large-area three-dimensional engraving while having high resolution and can further compress the thickness size of the three-dimensional structure.

[0010] The present invention first provides a super-resolution maskless exposure device based on a dual-color dual-step absorption effect, comprising:

[0011] A first optical path is used to generate a first laser beam, comprising a first laser light source, a first digital micromirror device, and a first microlens array. The laser beam emitted by the first laser light source is incident on the first digital micromirror device and is incident on the first microlens array after being reflected;

[0012] A second optical path, for generating a second laser beam, comprises a second laser light source, a second digital micromirror device, and a second microlens array, wherein the laser beam emitted by the second laser light source is incident on the second digital micromirror device and is incident on the second microlens array after being reflected;

[0013] The beam combining optical path includes a dichroic mirror, a scanning lens and an objective lens; the dichroic mirror is used to combine the first laser beam and the second laser beam generated by the first optical path and the second optical path, the centers of the first laser beam and the second laser beam coincide, the laser point array after combining is imaged twice through the scanning lens and the objective lens, and then reaches the three-dimensional sample platform for exposure, acts on the photoresist on the three-dimensional sample platform, and realizes maskless exposure three-dimensional direct writing.

[0014] Preferably, the first optical path is further provided with a first optical fiber, a first collimator, a first light homogenizer, a first quartz light rod, and a first reflector between the first laser light source and the first digital micromirror device, the first optical fiber is connected to the first laser light source and the first collimator at both ends respectively, the first laser light source emits a laser beam which passes through the first optical fiber and the first collimator to form a collimated laser beam, which is then homogenized through the first light homogenizer and the first quartz light rod to obtain a uniform light spot, which is then reflected to the first digital micromirror device through the first reflector;

[0015] The second optical path is also provided with a second optical fiber, a second collimator, a second light homogenizer, a second quartz light rod, and a second reflector between the second laser light source and the second digital micromirror device. The two ends of the second optical fiber are respectively connected to the second laser light source and the second collimator. The second laser light source emits a laser beam that passes through the second optical fiber and the second collimator to form a collimated laser beam, which is then homogenized through the second light homogenizer and the second quartz light rod to obtain a uniform light spot, and is reflected to the second digital micromirror device through the second reflector.

[0016] Preferably, a first lens and a second lens for beam expansion are provided between the first digital micromirror device and the first microlens array;

[0017] A third lens and a fourth lens for beam expansion are arranged between the second digital micromirror device and the second microlens array.

[0018] More preferably, the spacing between the microlenses on the first microlens array and the second microlens array is proportionally magnified to the spacing between the individual micromirrors on the first digital micromirror device and the second digital micromirror device, and the magnification is the same as the beam expansion factor of the combination of the first lens, the second lens, and the third lens and the fourth lens;

[0019] Furthermore, the microlenses on the first microlens array and the second microlens array correspond one-to-one to the micromirrors on the first digital micromirror device and the second digital micromirror device, respectively, and their centers coincide with each other.

[0020] Preferably, the number, arrangement pattern and spacing of micromirrors on the first digital micromirror device and the second digital micromirror device are the same,

[0021] Moreover, the centers of the laser point formed by the single micromirror on the first digital micromirror device converging through the first microlens array and the laser point formed by the corresponding single micromirror on the second digital micromirror device converging through the second microlens array do not completely overlap after the dichroic mirror combines the beams. There is a tiny displacement that does not exceed half of the sum of the wavelengths of the two laser beams, so that the overlapping part forms a writing spot smaller than the diffraction limit.

[0022] More preferably, after the laser point formed by the single micromirror on the first digital micromirror device converging through the first microlens array and the laser point formed by the corresponding single micromirror on the second digital micromirror device converging through the second microlens array are combined by the dichroic mirror, the focusing positions do not completely overlap in the Z-axis direction along the propagation of light, thereby further compressing the structural size in the Z-axis direction.

[0023] Preferably, the number of pixels of the first digital micromirror device and the second digital micromirror device is 960×540, 1280×720 or 1920×1080. The number of microlenses on the first microlens array and the second microlens array should be no less than the number of pixels on the corresponding first digital micromirror device and the second digital micromirror device. Generally, the number of microlenses should be slightly greater than the number of pixels to facilitate alignment of the two.

[0024] Preferably, the three-dimensional sample stage is tilted to the laser point array after beam combination, and the tilt angle is ≤20°. Preferably, the tilt angle is 5°~20°. The purpose of the tilt angle is to allow the laser point array to be tilted with the three-dimensional sample stage when the photoresist is exposed and directly written, that is, to perform tilted scanning exposure during writing to fill the gap between adjacent points and achieve continuous and complete exposure of the entire surface.

[0025] The present invention improves the resolution mainly through two ways: one is the microlens array, which directly reduces the size of a single pixel, adjusts the square pixels of the original digital micromirror device to form a smaller circular laser point array, and weakens the pixelation effect of the digital micromirror device; the other is that there is a slight displacement between the two light spots during engraving, reducing the area of ​​the overlapping part. The tilted scanning has two main functions: one is to fill the gap between adjacent points, realize continuous and complete exposure of the entire surface, and improve the writing efficiency. If it is not tilted, a discrete point array will be formed after passing through the microlens array; the other is to reduce the sawtooth effect, which can process a lithography pattern with smoother edges.

[0026] Preferably, the super-resolution maskless exposure device based on the two-color two-step absorption effect further includes a fifth lens and a charge-coupled device. The combined laser point array passes through the fifth lens to reach the charge-coupled device, and the charge-coupled device is used to monitor the laser point array in real time.

[0027] The present invention also provides a super-resolution maskless exposure method based on a two-color two-step absorption effect. Using the super-resolution maskless exposure device based on the two-color two-step absorption effect, the first laser beam and the second laser beam respectively generated by the first optical path and the second optical path are combined through a beam combining optical path and then reach a three-dimensional sample platform for exposure, thereby acting on the photoresist on the three-dimensional sample platform to realize maskless exposure three-dimensional direct writing.

[0028] The beneficial effects of the present invention are: the present invention can form a laser direct writing point array consisting of more than one million points on the photoresist, and each independent point can be quickly "switched on and off" regulated, and has the following characteristics:

[0029] 1. With fast processing capability, the present invention utilizes digital micromirror devices to realize the regulation of independent laser point switches, and the regulation speed can reach kHz, laying the foundation for fast processing.

[0030] 2. It has the ability to process large-area complex structures. The present invention makes full use of the large-scale matrix pixels of the digital micromirror device to form a laser direct writing point array with more than one million points, which can quickly complete the engraving of large-area complex structures.

[0031] 3. With high resolution, the present invention further focuses the smallest pixel unit in the digital micromirror device into a smaller action point through a microlens array, and utilizes the dual-color dual-step absorption effect to achieve a high writing resolution exceeding the diffraction limit.

[0032] Furthermore, due to focusing through the microlens array, the size of each pixel after focusing is reduced and the spacing between adjacent pixels is increased, so that oblique scanning can be applied.

[0033] 4. Maskless exposure. The present invention does not require the use of a mask, simplifies the manufacturing process, reduces costs, and independently incidents through two light paths, which are combined only after passing through a digital micromirror device and a microarray lens respectively. The two light paths before combining can be adjusted separately, which improves flexibility and can quickly respond to the needs of different graphic designs.

[0034] The present invention effectively solves the problem of high production volume and high resolution in the current surface projection lithography technology based on digital micromirror devices. The device is used to generate a laser point array that can be quickly and specifically controlled, and acts on the material to achieve a two-color two-step absorption effect, which can provide the necessary technical basis for the realization of a fast, high-precision, large-area, complex structure direct writing maskless exposure system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of a super-resolution maskless exposure device based on a two-color two-step absorption effect of the present invention.

[0036] Figure 2 It is a schematic diagram of the super-resolution maskless exposure direct writing process based on the dual-color dual-step absorption effect of the present invention.

[0037] Figure numerals: 1-first laser light source, 2-first optical fiber, 3-first collimator, 4-first light homogenizer, 5-first quartz light rod, 6-first reflector, 7-first digital micromirror device, 8-first lens, 9-second lens, 10-first microlens array, 11-second laser light source, 12-second optical fiber, 13-second collimator, 14-second light homogenizer, 15-second quartz light rod, 16-second reflector, 17-second digital micromirror device, 18-third lens, 19-fourth lens, 20-second microlens array, 21-dichroic mirror, 22-scanning lens, 23-objective lens, 24-three-dimensional sample stage, 25-fifth lens, 26-charge coupled device, 27-computer. DETAILED DESCRIPTION

[0038] The present invention will be further described below by way of examples and drawings, but the protection scope of the present invention shall not be limited thereto.

[0039] A super-resolution maskless exposure device based on a two-color two-step absorption effect, such as Figure 1 As shown, it includes: a first laser light source 1, a first optical fiber 2, a first collimator 3, a first light homogenizer 4, a first quartz light rod 5, a first reflector 6, a first digital micromirror device 7, a first lens 8, a second lens 9, a first microlens array 10, a second laser light source 11, a second optical fiber 12, a second collimator 13, a second light homogenizer 14, a second quartz light rod 15, a second reflector 16, a second digital micromirror device 17, a third lens 18, a fourth lens 19, a second microlens array 20, a dichroic mirror 21, a scanning lens 22, an objective lens 23, a three-dimensional sample stage 24, a fifth lens 25, a charge coupled device 26, and a computer 27.

[0040] The above structure is divided into a first optical path, a second optical path and a combined optical path according to the optical path.

[0041] The first optical path is used to generate a first laser beam, and includes a first laser light source 1, a first digital micromirror device 7, and a first microlens array 10. The laser beam emitted by the first laser light source 1 is incident on the first digital micromirror device 7 and is reflected and then incident on the first microlens array 10.

[0042] The first optical path is further provided with a first optical fiber 2, a first collimator 3, a first light homogenizer 4, a first quartz light rod 5, and a first reflector 6 between the first laser light source 1 and the first digital micromirror device 7. The first optical fiber 2 is connected to the first laser light source 1 and the first collimator 3 at both ends. The first laser light source 1 emits a laser beam which is formed into a collimated laser beam through the first optical fiber 2 and the first collimator 3, and then homogenized through the first light homogenizer 4 and the first quartz light rod 5 to obtain a uniform light spot, which is reflected to the first digital micromirror device 7 through the first reflector 6. A first lens 8 and a second lens 9 for beam expansion are provided between the first digital micromirror device 7 and the first microlens array 10.

[0043] The second optical path is used to generate a second laser beam, including a second laser light source 11, a second digital micromirror device 17, and a second microlens array 20. The laser beam emitted by the second laser light source 11 is incident on the second digital micromirror device 17 and is reflected and then incident on the second microlens array 20.

[0044] The second optical path is also provided with a second optical fiber 12, a second collimator 13, a second light homogenizer 14, a second quartz light rod 15, and a second reflector 16 between the second laser light source 11 and the second digital micromirror device 17. The two ends of the second optical fiber 12 are respectively connected to the second laser light source 11 and the second collimator 13. The second laser light source 11 emits a laser beam which passes through the second optical fiber 12 and the second collimator 13 to form a collimated laser beam, which is then homogenized through the second light homogenizer 14 and the second quartz light rod 15 to obtain a uniform light spot, and is reflected to the second digital micromirror device 17 through the second reflector 16.

[0045] A third lens 18 and a fourth lens 19 for beam expansion are disposed between the second digital micromirror device 17 and the second microlens array 20 .

[0046] The beam combining optical path includes a dichroic mirror 21, a scanning lens 22 and an objective lens 23; the dichroic mirror 21 is used to combine the first laser beam and the second laser beam generated by the first optical path and the second optical path. One of the first laser beam and the second laser beam passes through the dichroic mirror 21, and the other is reflected by the dichroic mirror 21. When the first laser beam and the second laser beam are perpendicular to each other and the arrangement angle of the dichroic mirror 21 is 45° with the first laser beam and the second laser beam respectively, the first laser beam and the second laser beam are combined by the dichroic mirror 21.

[0047] The centers of the first laser beam and the second laser beam coincide, and the combined laser point array is imaged again through the scanning lens 22 and the objective lens 23, and then reaches the three-dimensional sample platform 24 for exposure, acting on the photoresist on the three-dimensional sample platform 24, realizing maskless exposure three-dimensional direct writing.

[0048] The spacing between the microlenses on the first microlens array 10 and the second microlens array 20 is magnified in a certain proportion to the spacing between the single micromirrors on the first digital micromirror device 7 and the second digital micromirror device 17, and the magnification is the same as the beam expansion factor of the combination of the first lens 8, the second lens 9, the third lens 18, and the fourth lens 19; and the microlenses on the first microlens array 10 and the second microlens array 20 correspond one-to-one to the micromirrors on the first digital micromirror device 7 and the second digital micromirror device 17, respectively, and their centers coincide.

[0049] The number, arrangement mode and spacing of micromirrors on the first digital micromirror device 7 and the second digital micromirror device 17 are the same, and the centers of the laser points formed by the convergence of a single micromirror on the first digital micromirror device 7 through the first microlens array 10 and the laser points formed by the convergence of a corresponding single micromirror on the second digital micromirror device 17 through the second microlens array do not completely overlap after the beams are combined by the dichroic mirror 21. In addition, the focus positions do not completely overlap in the Z-axis direction along the propagation of light.

[0050] The number of pixels of the first digital micromirror device 7 and the second digital micromirror device 17 is 960×540, 1280×720 or 1920×1080. The number of microlenses on the first microlens array 10 and the second microlens array 20 should be no less than the number of pixels on the corresponding first digital micromirror device 7 and the second digital micromirror device 17. Generally, the number of microlenses should be slightly greater than the number of pixels to facilitate alignment between the two.

[0051] The three-dimensional sample stage 24 is tilted to the laser point array after beam combination, and the tilt angle is ≤20°. The preferred tilt angle is 5°~20°. The purpose of the tilt angle is to allow the laser point array to be tilted with the three-dimensional sample stage 24 when the photoresist is exposed and written directly, that is, to perform tilted scanning exposure during writing to fill the gap between adjacent points and achieve continuous and complete exposure of the entire surface.

[0052] The super-resolution maskless exposure device based on the dual-color dual-step absorption effect of the present invention further includes a fifth lens 25 and a charge coupled device 26. The combined laser point array passes through the fifth lens 25 to reach the charge coupled device 26. The charge coupled device 26 is used to monitor the laser point array in real time.

[0053] The super-resolution maskless exposure device based on the dual-color dual-step absorption effect of the present invention further comprises a computer 27, and the writing software in the computer 27 is used to control the operation of the device.

[0054] The present invention also provides a super-resolution maskless exposure method based on a two-color two-step absorption effect. Using the super-resolution maskless exposure device based on a two-color two-step absorption effect of the present invention, the first laser beam and the second laser beam respectively generated by the first optical path and the second optical path are combined through a beam combining optical path and then reach the three-dimensional sample platform 24 for exposure, thereby acting on the photoresist on the three-dimensional sample platform 24 to realize maskless exposure three-dimensional direct writing.

[0055] In a specific embodiment, using Figure 1 The super-resolution maskless exposure method based on the dual-color dual-step absorption effect of the device shown is as follows:

[0056] The first laser light source 1 with a wavelength of 405nm emits a laser beam with a diameter of about 1mm, which passes through the first optical fiber 2 and the first collimator 3 to form a collimated laser beam, and then passes through the first light homogenizer 4 and the first quartz light rod 5 for homogenization to form a rectangular light spot of about 20mm×10mm, and the uniformity of the light spot reaches more than 99%. After being reflected by the first reflector 6, the rectangular light spot is incident on the first digital micromirror device 7. In this embodiment, a DLP9500 digital micromirror device produced by Texas Instruments is selected, with a pixel number of 1920×1080 and a micromirror size of 10.8 μm, which can be used in the visible light band. The first digital micromirror device 7 reflects the incident light beam to the first lens 8. The combined magnification of the first lens 8 and the second lens 9 is about 3.26 times. The outgoing light beam of the first digital micromirror device 7 becomes a parallel light beam magnified by 3.26 times, passes through the first microlens array 10 (microlens spacing is 35.269 μm, and the radius of curvature is 100 μm), reaches the dichroic mirror 21, and then enters the subsequent optical path system.

[0057] The second laser light source 11 with a wavelength of 520nm emits a laser beam with a diameter of about 1mm. The laser beam passes through the second optical fiber 12 and the second collimator 13 to form a collimated laser beam, and then passes through the second light homogenizer 14 and the second quartz light rod 15 for homogenization to form a rectangular light spot of about 20mm×10mm, and the uniformity of the light spot reaches more than 99%. After the rectangular light spot is reflected by the second reflector 16, it is incident on the second digital micromirror device 17. The second digital micromirror device 17 selects the DLP9500 digital micromirror device produced by Texas Instruments. The second digital micromirror device 17 reflects the incident light beam into the third lens 18. The combined magnification of the third lens 18 and the fourth lens 19 is about 3.26 times. The outgoing light beam of the second digital micromirror device 17 becomes a parallel light beam magnified by 3.26 times. After passing through the second microlens array 20, it reaches the dichroic mirror 21 and then enters the subsequent optical path system.

[0058] The dichroic mirror 21 selects a short-wave dichroic mirror, such as the DMSP490 type with a cutoff frequency of 490nm; the dichroic mirror 21 transmits the first incident light beam with a wavelength of 405nm and reflects the second incident light beam with a wavelength of 520nm. The spacing of the microlenses is the same as the pixel spacing after the first digital micromirror device 7 and the second digital micromirror device 17 are magnified by 3.26 times. The microlens array regulates the parallel incident light beams with wavelengths of 405nm and 520nm, reduces the size of the original single pixel, thereby increasing the pixel spacing, and forming an array of laser dots with equal spacing on the focal plane. The dot array is imaged twice by the scanning lens 22 and the objective lens 23, further reducing the size of the single pixel of the dot array and the spacing between pixels, and then reaches the three-dimensional sample stage 24 for exposure. After part of the energy of the laser dot array passes through the three-dimensional sample stage 24, it is imaged onto the charge coupled device 26 through the fifth lens 25. The charge coupled device 26 is connected to the computer 27 for detection and feedback of the laser dot array.

[0059] During the exposure process, the three-dimensional sample stage 24 is used to control the movement of the photoresist material in the three-dimensional directions of x, y, and z, and the writing speed is controlled to be 10μm / s~1m / s. By moving the digital micromirror device and the microlens array, the centers of each laser point of the two beams are not completely overlapped, and there is a small displacement, which does not exceed half of the sum of the wavelengths of the two laser beams, forming a writing spot less than the diffraction limit, and the focus position has a small displacement in the z-axis direction, and the displacement distance does not exceed 300nm. By adjusting the z-axis displacement distance, the overlap area range of the two laser focus planes is changed to adjust the height of the three-dimensional structure to be written. By controlling the laser power output by the first laser light source 1 and the second laser light source 11, the optical power density of the absorption beam acting on the photoresist is regulated, so that the photoinitiator, after absorbing the first absorption light, immediately under the action of the second absorption light, the electrons in the photoinitiator continue to complete triplet absorption, randomly trigger a series of photochemical reactions, complete the two-color double-step absorption effect, and realize super-resolution writing.

[0060] The first digital micromirror device 7 and the second digital micromirror device 17 are used to adjust the pattern of the action point array. In this embodiment, an 11×10 array is used, and scanning is performed at an angle of 14.04°. When a structure of a “+” pattern needs to be engraved, as shown in FIG. Figure 2 As shown, the black dot indicates that a laser point is regulated to be in the on state through the digital micromirror device to expose the material, and the hollow dot indicates that the laser point is regulated to be in the off state and does not act on the material.

[0061] Before the actual exposure, the computer 27 first divides the image to be written, and then respectively calculates the action status of each array point during the movement of the three-dimensional sample stage 24, and then controls the three-dimensional sample stage 24, the first digital micromirror device 7 and the second digital micromirror device 17 according to the calculation results. First, according to the image to be written, a part of the array action points are controlled to be turned on and a part to be turned off. The action points are turned on at the positions to be written, and the action points are turned off at the positions not to be written; then, the computer 27 controls the three-dimensional sample stage 24 to move in one direction, and then controls the switch of each action point through the first digital micromirror device 7 and the second digital micromirror device 17 according to the image to be written. Figure 2 As shown, it can be found that during the movement, the photoresist polymerizes to form a structure in the area scanned by the turned-on action point; finally, through the movement of the three-dimensional sample stage 24 and the independent regulation of the action point by the first digital micromirror device 7 and the second digital micromirror device 17, after the array point scans the entire image area to be written, the required structure is written, and its speed is increased by dozens of times compared to single-point writing.

[0062] The above description is only an example of a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A super-resolution maskless exposure device based on a two-color two-step absorption effect, characterized in that: include: A first optical path is used to generate a first laser beam, comprising a first laser light source, a first digital micromirror device, and a first microlens array. The laser beam emitted by the first laser light source is incident on the first digital micromirror device and is incident on the first microlens array after being reflected; A second optical path, for generating a second laser beam, comprises a second laser light source, a second digital micromirror device, and a second microlens array, wherein the laser beam emitted by the second laser light source is incident on the second digital micromirror device and is incident on the second microlens array after being reflected; The beam combining optical path includes a dichroic mirror, a scanning lens and an objective lens; the dichroic mirror is used to combine the first laser beam and the second laser beam generated by the first optical path and the second optical path, so that the centers of the first laser beam and the second laser beam coincide with each other, and the laser point array after the beam combining is imaged twice through the scanning lens and the objective lens, and then reaches the three-dimensional sample stage for exposure, acts on the photoresist on the three-dimensional sample stage, and realizes maskless exposure three-dimensional direct writing; The number, arrangement pattern and spacing of micromirrors on the first digital micromirror device and the second digital micromirror device are the same, and the centers of a laser point formed by converging a single micromirror on the first digital micromirror device through a first microlens array and a laser point formed by converging a corresponding single micromirror on the second digital micromirror device through a second microlens array do not completely overlap after the dichroic mirror combines the beams, and there is a slight displacement that does not exceed half of the sum of the wavelengths of the two laser beams.

2. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 1, characterized in that: The first optical path is further provided with a first optical fiber, a first collimator, a first light homogenizer, a first quartz light rod, and a first reflector between the first laser light source and the first digital micromirror device. The first optical fiber is connected to the first laser light source and the first collimator at both ends. The first laser light source emits a laser beam which passes through the first optical fiber and the first collimator to form a collimated laser beam, which is then homogenized through the first light homogenizer and the first quartz light rod to obtain a uniform light spot, and then reflected to the first digital micromirror device through the first reflector; The second optical path is also provided with a second optical fiber, a second collimator, a second light homogenizer, a second quartz light rod, and a second reflector between the second laser light source and the second digital micromirror device. The two ends of the second optical fiber are respectively connected to the second laser light source and the second collimator. The second laser light source emits a laser beam that passes through the second optical fiber and the second collimator to form a collimated laser beam, which is then homogenized through the second light homogenizer and the second quartz light rod to obtain a uniform light spot, and is reflected to the second digital micromirror device through the second reflector.

3. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 1, characterized in that: A first lens and a second lens for beam expansion are provided between the first digital micromirror device and the first microlens array; A third lens and a fourth lens for beam expansion are arranged between the second digital micromirror device and the second microlens array.

4. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 3, characterized in that: The spacing between the microlenses on the first microlens array and the second microlens array is magnified in a certain ratio to the spacing between the individual micromirrors on the first digital micromirror device and the second digital micromirror device, and the magnification is the same as the beam expansion multiple of the combination of the first lens, the second lens, and the third lens and the fourth lens; Furthermore, the microlenses on the first microlens array and the second microlens array correspond one-to-one to the micromirrors on the first digital micromirror device and the second digital micromirror device, respectively, and their centers coincide with each other.

5. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 1, characterized in that: After the laser point formed by the single micromirror on the first digital micromirror device converging through the first microlens array and the laser point formed by the corresponding single micromirror on the second digital micromirror device converging through the second microlens array are combined by the dichroic mirror, the focusing positions in the Z-axis direction along the propagation of light do not completely overlap.

6. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 1, characterized in that: The number of pixels of the first digital micromirror device and the second digital micromirror device is 960×540, 1280×720 or 1920×1080.

7. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 1, characterized in that: The three-dimensional sample stage is tilted to the beam-combined laser point array, and the tilt angle is ≤20°.

8. The super-resolution maskless exposure device based on the dual-color dual-step absorption effect according to claim 1, characterized in that: It also includes a fifth lens and a charge coupled device. The combined laser point array passes through the fifth lens and reaches the charge coupled device. The charge coupled device is used to monitor the laser point array in real time.

9. A super-resolution maskless exposure method based on a two-color two-step absorption effect, characterized in that: Using the super-resolution maskless exposure device based on the two-color two-step absorption effect as described in any one of claims 1 to 8, the first laser beam and the second laser beam respectively generated by the first optical path and the second optical path are combined through the beam combining optical path and then reach the three-dimensional sample platform for exposure, and act on the photoresist on the three-dimensional sample platform to realize maskless exposure three-dimensional direct writing.

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