An ultraviolet mixed wave illumination system for precision exposure

Abstract

The utility model relates to a kind of for precise exposure ultraviolet mixed wave lighting system, including light source unit, it includes beam combining mirror subassembly and at least two LED module, at least two the first output light of the LED module is output after wavelength beam combining by the beam combining mirror subassembly;Light uniformity unit, receive the first output light from light source unit, mix first output light, to form light uniformity beam output;Shaping unit, its receive the light uniformity beam from light uniformity unit, specified light spot signal is output to the surface to be imaged after shaping processing;Light source unit, light uniformity unit and the shaping unit are sequentially arranged along optical path direction.The utility model can be combined by multiple LED module beam to adjust high brightness, fundamentally eliminate coherent noise using light uniformity unit;The optical system of the utility model has flexibility, different wavelength and quantity of LED module can be replaced according to use requirement, and the configuration of light uniformity unit and shaping unit is adjusted, so different application scenarios can be adapted, convenient optimization and maintenance.

Description

Technical Field

[0001] This utility model relates to the field of precision light source imaging technology, and in particular to an ultraviolet mixing illumination system for precision exposure. Background Technology

[0002] In advanced manufacturing and inspection fields such as semiconductor lithography, precision metrology, microscopic imaging, and high-end displays, optical systems, as core components, directly determine the imaging resolution, contrast, and yield of the equipment. Different application scenarios place drastically different demands on the output characteristics of the light source: for example, some lithography processes require a pure single-wavelength beam to achieve extremely high optical resolution and avoid chromatic aberration; while other imaging devices used to detect three-dimensional morphology or specific materials may require illumination light containing multiple specific wavelengths to simultaneously acquire multi-dimensional information. Currently, in these demanding fields, laser light sources have become one of the mainstream choices due to their high brightness, high directionality, and extremely narrow spectral linewidth (i.e., excellent monochromaticity). These characteristics of lasers enable them to support extremely high resolution and powerful energy transfer efficiency.

[0003] However, the existing technology has a drawback: due to the inherent characteristics of lasers, they possess high spatiotemporal coherence. When this highly coherent beam illuminates an optical system or the surface of an object, it is highly susceptible to a series of harmful interference effects, including speckle effects. When coherent light is scattered by the fine structures of internal components of the optical system or the sample surface, interference occurs between different scattered beams, forming randomly distributed bright and dark spots (i.e., speckle) on the imaging surface. This speckle noise severely obscures the true details of the image, reduces the signal-to-noise ratio and contrast, and significantly impacts precision detection and imaging quality. In addition, interference fringes are formed. The beam reflects multiple times between the surfaces of elements such as lenses and prisms. These reflected beams form stable interference fringes with the main beam, which are superimposed on the final image, thus affecting the accuracy of imaging. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide an ultraviolet mixed-wave illumination system for precision exposure, which can flexibly output a beam that meets the spectral requirements (single wavelength or multiple wavelengths) and has low coherence according to specific application needs, thereby obtaining a high-resolution, high-uniformity, and low-noise high-quality light field on the imaging surface.

[0005] To solve the above-mentioned technical problems, this utility model provides an ultraviolet mixing illumination system for precision exposure, comprising: The light source unit includes a beam combiner assembly and at least two LED modules, wherein the at least two LED modules are wavelength-combined by the beam combiner assembly to output a first output light. A homogenizing unit receives the first output light from the light source unit and mixes the first output light to form a homogenized beam output; The shaping unit receives the uniform light beam from the uniform light unit, and after shaping, outputs a specified light spot signal to the surface to be imaged. The light source unit, the light homogenizing unit, and the shaping unit are arranged sequentially along the optical path.

[0006] In one embodiment of this utility model, the light source unit includes a first LED module, a second LED module, and a third LED module; the first LED module outputs a first wavelength beam in a first direction, the second LED module outputs a second wavelength beam in a second direction, and the third LED module outputs a third wavelength beam in a third direction; wherein the first direction and the second direction are perpendicular, and the third direction is opposite to the second direction; the beam combiner assembly includes a first beam combiner and a second beam combiner, the first beam combiner is used to reflect the second wavelength beam, and the second beam combiner is used to reflect the first wavelength beam, so that the first wavelength beam, the second wavelength beam, and the third wavelength beam are combined to form the first output light.

[0007] In one embodiment of the present invention, each LED module includes an array of LED beads.

[0008] In one embodiment of this utility model, the light-uniforming unit includes a light bar, the axial direction of which is consistent with the emission direction of the first output light.

[0009] In one embodiment of this utility model, the light-diffusing unit includes a compound eye lens.

[0010] In one embodiment of this utility model, the light source unit includes a first LED module, a second LED module, and an LD laser module. The LD laser module, together with the first LED module and the second LED module, forms the first output light. The LD laser module includes a laser fiber, a laser emission port, a laser collimating lens, and a laser reflector. The laser fiber is connected to the laser emission port to emit laser light. The laser light passes through the laser collimating lens and enters the laser reflector to be combined with the first wavelength beam of the first LED module and the second wavelength beam of the second LED module.

[0011] In one embodiment of the present invention, the shaping unit includes a relay lens assembly, which includes a front group of relay lenses, a relay mirror, a relay lens aperture, and a rear group of relay lenses arranged sequentially along the optical path direction.

[0012] In one embodiment of this utility model, the shaping unit includes a quartz fiber bundle or a liquid fiber, and the uniform light beam is coupled to the quartz fiber bundle or the liquid fiber.

[0013] In one embodiment of this utility model, a wind-cooled heat dissipation component is further included, which is used in conjunction with the quartz fiber bundle or the liquid fiber.

[0014] In one embodiment of the present invention, a liquid cooling heat dissipation component is further included, the liquid cooling heat dissipation component including a heat sink plate, the heat sink plate being attached to at least two of the LED modules.

[0015] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art: This invention discloses an ultraviolet mixed-wave illumination system for precision exposure, comprising a light source unit, a homogenizing unit, and a shaping unit. The light source unit uses at least two LED modules coupled together, enabling flexible combinations of at least two wavelengths. Compared to existing laser light sources, this system ensures a balance between output spot brightness and low coherence. Brightness is increased by combining multiple LED modules, and coherent noise is fundamentally eliminated using the homogenizing unit. Furthermore, the optical system of this invention is flexible, allowing for the replacement of LED modules with different wavelengths and quantities, and adjustment of the homogenizing and shaping units to adapt to different application scenarios (such as lithography at different wavelengths and microscopic imaging at different magnifications), facilitating optimization and maintenance. Attached Figure Description

[0016] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the first embodiment of the preferred embodiment of the light source unit and the light uniform unit of this utility model.

[0018] Figure 2 This is a schematic diagram of the second embodiment of the light source unit and the light uniform unit of the preferred embodiment of this utility model.

[0019] Figure 3 This is a schematic diagram of the structure of the uniform light unit and the shaping unit in a preferred embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the overall structure of the optical system according to a preferred embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the third embodiment of the light source unit and the light uniform unit of the preferred embodiment of this utility model.

[0022] Explanation of reference numerals in the accompanying drawings: 10, First output light; 11, First LED module; 12, Second LED module; 13, Third LED module; 14, First beam combiner; 15, Second beam combiner; 21, Light bar; 22, Compound eye lens; 30, Front group of relay lens; 31, Relay reflector; 32, Relay lens aperture; 33, Relay lens rear group; 34, Quartz fiber bundle; 40, Laser fiber; 41, Laser emission port; 42, Laser collimating lens; 43, Laser reflector. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention. Example 1

[0024] Reference Figures 1 to 5 As shown, this utility model discloses an ultraviolet mixing illumination system for precision exposure, including a light source unit. The light source unit includes a beam combiner assembly and at least two LED modules. The at least two LED modules output a first output light 10 after wavelength beam combining through the beam combiner assembly. The optical system further includes a light homogenizing unit, which receives the first output light 10 from the light source unit, mixes the first output light, and forms a uniform light beam output. The optical system also includes a shaping unit, which receives the uniform light beam from the uniform light unit, and outputs a specified spot signal to the surface to be imaged after shaping.

[0025] The light source unit, the homogenizing unit, and the shaping unit are arranged sequentially along the optical path. The optical system operates as follows: light emitted from at least two LED modules is combined to form a high-brightness first output light 10. This first output light 10 is then fully homogenized in the homogenizing unit. The homogenized beam then enters the shaping unit, which shapes and transmits the homogenized light spot, ultimately forming a designated output light spot with high energy density, uniform distribution, no coherent noise, and the required size and shape on the imaging surface.

[0026] Therefore, it can be understood that the ultraviolet mixed-wave illumination system for precision exposure protected by this utility model includes a light source unit, a homogenizing unit, and a shaping unit. The light source unit uses at least two LED modules coupled together to enable flexible combination of at least two wavelengths. Compared with laser light sources in the prior art, it can ensure a balance between output spot brightness and low coherence. By combining multiple LED modules together, the brightness is increased, and the homogenizing unit fundamentally eliminates coherent noise. At the same time, the optical system is flexible, and different wavelengths and numbers of LED modules can be replaced according to usage requirements, and the configuration of the homogenizing unit and the shaping unit can be adjusted, thereby adapting to different application scenarios (such as photolithography of different wavelengths and microscopic imaging with different magnification), facilitating optimization and maintenance.

[0027] In a preferred embodiment, each LED module can be a single LED chip or a module consisting of multiple integrated LED chips to provide higher initial luminous flux.

[0028] Preferably, the light source unit includes a first LED module 11, a second LED module 12, and a third LED module 13. The first LED module 11 outputs a first wavelength beam in a first direction, the second LED module 12 outputs a second wavelength beam in a second direction, and the third LED module 13 outputs a third wavelength beam in a third direction. Wherein, the first direction is perpendicular to the second direction, and the third direction is opposite to the second direction.

[0029] Specifically, in this embodiment, the wavelength of the first wavelength beam is 350-390nm, the wavelength of the second wavelength beam is 350-390nm, and the wavelength of the third wavelength beam is 390-410nm. Preferably, the wavelength of the first wavelength beam is 365nm, the wavelength of the second wavelength beam is 385nm, and the wavelength of the third wavelength beam is 405nm.

[0030] To achieve high brightness output, the light source unit adopts a multi-module beam combining design. Specifically, the beam combining mirror assembly includes a first beam combining mirror 14 and a second beam combining mirror 15. The first beam combining mirror 14 is used to reflect the second wavelength beam, and the second beam combining mirror 15 is used to reflect the first wavelength beam, so that the first wavelength beam, the second wavelength beam, and the third wavelength beam are combined to form the first output light 10.

[0031] Of course, in other implementations, multiple LED modules can be spatially combined, that is, multiple LED modules can be arranged closely in space so that their emitted beams enter the subsequent optical system together. Furthermore, a polarizing beam splitter can be used to combine the beams of two LED modules emitting linearly polarized light with perpendicular polarization directions into a single beam. Additionally, if multi-wavelength illumination is required, LED modules emitting different center wavelengths (such as ultraviolet, blue, and green light) can be selected and combined using optical elements such as dichroic mirrors to achieve spectrum customization.

[0032] Of course, in other embodiments, depending on the user's different requirements for the number of wavelengths, the light source unit may also include more than three LED modules. Accordingly, the number and placement of the beam combiner in the beam combiner assembly can also be adaptively adjusted according to changes in the number of LED modules.

[0033] In a preferred embodiment, at least two of the LED modules include an array of LED beads. Specifically, the number of beads in each LED module is increased from 2 to 3*4. Of course, in other embodiments, the number and arrangement of beads in each LED module are not limited to 3*4; other array arrangements are also possible. This configuration allows the brightness of the LED modules to be superimposed, resulting in more uniform emitted light and effectively avoiding lead wires caused by single-point failures, thus improving the reliability and stability of the light source.

[0034] The homogenizing unit receives the first output light 10 from the light source unit and can scatter and mix the first output light 10 with uneven intensity distribution, thereby destroying its spatial coherence and outputting a homogenized beam with highly uniform light intensity distribution on the cross-section.

[0035] In a preferred embodiment, the light-uniforming unit includes a light rod 21, the axial direction of which is consistent with the emission direction of the first output light 10. Specifically, the light rod 21 is a hollow light tube or a solid optical glass rod with a highly reflective internal mirror surface. Therefore, after multiple reflections within it, the light is uniformly distributed at the light outlet. The light rod 21 can be a cuboid, cylinder, or cone.

[0036] In some other embodiments, the homogenizing unit includes a compound eye lens 22. A compound eye lens is an optical device designed to mimic the compound eye structure of insects (such as flies and bees). It consists of numerous tiny lens units (usually square or hexagonal) densely arranged on a substrate to form a lens array; it can achieve the segmentation, correction, and superposition of the light source, thereby enabling the emitted light to be completely superimposed on the target surface; achieving extremely high illumination uniformity, improving the utilization rate of light energy, and effectively controlling the shape and size of the output light spot.

[0037] Furthermore, the light-uniforming unit may also include a diffuser, which may include frosted glass or a holographic diffuser to disperse the light spot through random phase modulation; to reduce energy loss, a low-angle, high-transmittance engineered diffuser is preferred. Of course, the light-uniforming unit may also employ other optical elements with light-uniforming effects.

[0038] The shaping unit receives the homogenized beam processed by the homogenizing unit and clearly images the light-emitting surface of the homogenizing unit (such as the light-emitting port of the light bar 21 or the superposition surface of the compound eye lens 22) onto the target imaging surface, while simultaneously achieving precise control over the size, shape, and collimation of the output light spot.

[0039] In a preferred embodiment, the shaping unit includes a relay lens assembly, as shown in the reference. Figure 3 As shown, the relay lens assembly includes a front relay lens group 30, a relay reflector 31, a relay lens aperture 32, and a rear relay lens group 33 arranged sequentially along the optical path direction; the uniform light beam passes through the front relay lens group 30 and exits to the relay reflector 31, is reflected by the relay reflector 31 and passes through the relay lens aperture 32, and finally exits to the rear relay lens group 33, and exits to the target imaging surface.

[0040] As a preferred implementation method, combined with Figure 4 As shown, in order to make the application scenarios more extensive, the shaping unit includes a quartz fiber bundle 34 or a liquid fiber, and the uniform beam is directly coupled to the quartz fiber bundle or the liquid fiber.

[0041] In order to dissipate heat from the quartz fiber bundle 34 or the liquid fiber, the optical system further includes a heat dissipation air cooling component, which works in conjunction with the quartz fiber bundle or the liquid fiber.

[0042] To dissipate heat from the LED modules of the light source unit, the optical system further includes a liquid cooling heat dissipation assembly. The liquid cooling heat dissipation assembly includes a heat sink plate that is attached to at least two of the LED modules. The heat sink plate has a liquid inlet and a liquid outlet. By injecting flowing water or other cooling liquid into the heat sink plate, effective heat dissipation of the at least two LED modules is achieved.

[0043] In another embodiment, the light source unit includes two LED modules, namely a first LED module 11 and a second LED module 12. Furthermore, the light source unit also includes an LD laser module, combined with... Figure 5As shown, the LD laser module, together with the first LED module and the second LED module, forms the first output light. Specifically, the LD laser module includes a laser fiber 40, a laser emission port 41, a laser collimating lens 42, and a laser reflector 43. The laser fiber 40 is connected to the laser emission port 41 to emit laser light. The laser light passes through the laser collimating lens 42 and enters the laser reflector 43 to be combined with the first wavelength beam of the first LED module 11 and the second wavelength beam of the second LED module 12. This is further combined with the compound eye lens 22 disposed in the homogenizing unit, thereby forming a scheme combining the LD laser module, the first LED module 11, the second LED module 12, and the compound eye lens 22. Example 2

[0044] This utility model also discloses an optical device, including an ultraviolet mixed-wave illumination system for precision exposure as described in Embodiment 1, wherein the optical device includes a lithography machine or an exposure machine.

[0045] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0047] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A UV mixing illumination system for precision exposure, characterized in that: include, The light source unit includes a beam combiner assembly and at least two LED modules, wherein the at least two LED modules are wavelength-combined by the beam combiner assembly to output a first output light. A homogenizing unit receives the first output light from the light source unit and mixes the first output light to form a homogenized beam output; The shaping unit receives the uniform light beam from the uniform light unit, and after shaping, outputs a specified light spot signal to the surface to be imaged. The light source unit, the light homogenizing unit, and the shaping unit are arranged sequentially along the optical path.

2. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: The light source unit includes a first LED module, a second LED module, and a third LED module; the first LED module outputs a first wavelength beam in a first direction, the second LED module outputs a second wavelength beam in a second direction, and the third LED module outputs a third wavelength beam in a third direction; wherein the first direction and the second direction are perpendicular, and the third direction is opposite to the second direction; the beam combiner assembly includes a first beam combiner and a second beam combiner, the first beam combiner is used to reflect the second wavelength beam, and the second beam combiner is used to reflect the first wavelength beam, so that the first wavelength beam, the second wavelength beam, and the third wavelength beam are combined to form the first output light.

3. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: Each of the LED modules includes an array of LED beads.

4. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: The light homogenizing unit includes a light bar, the axial direction of which is consistent with the emission direction of the first output light.

5. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: The light-diffusing unit includes a compound eye lens.

6. The ultraviolet mixing illumination system for precision exposure according to claim 5, characterized in that: The light source unit includes a first LED module, a second LED module, and an LD laser module. The LD laser module, together with the first LED module and the second LED module, forms the first output light. The LD laser module includes a laser fiber, a laser emission port, a laser collimating lens, and a laser reflector. The laser fiber is connected to the laser emission port to emit laser light. The laser light passes through the laser collimating lens and enters the laser reflector to be combined with the first wavelength beam of the first LED module and the second wavelength beam of the second LED module.

7. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: The shaping unit includes a relay lens assembly, which includes a front group of relay lenses, a relay reflector, a relay lens aperture, and a rear group of relay lenses arranged sequentially along the optical path direction.

8. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: The shaping unit includes a quartz fiber bundle or a liquid fiber, and the uniform beam is coupled to the quartz fiber bundle or the liquid fiber.

9. The ultraviolet mixing illumination system for precision exposure according to claim 8, characterized in that: It also includes a wind-cooled heat dissipation component, which is used in conjunction with the quartz fiber bundle or the liquid fiber.

10. The ultraviolet mixing illumination system for precision exposure according to claim 1, characterized in that: It also includes a liquid cooling heat dissipation component, which includes a heat sink plate that is attached to at least two of the LED modules.

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