Projection exposure system

Abstract

The invention provides a projection exposure system, a self-luminous array assembly comprises a self-luminous light source array and a shaping micro-lens array, the shaping micro-lens array is located on one side of a light emitting surface of the self-luminous light source array, and the self-luminous light source array is used for generating a pixel luminous point light source. The shaping micro lens array is used for shaping light spots of the pixel light-emitting point light source and forming uniformly distributed array light spots, the array light spots project light spot images corresponding to the array light spots to the surface of the workpiece table through the projection lens assembly, and the projection lens assembly is further used for adjusting light spot displacement to achieve splicing error compensation. According to the invention, a lighting system and a space adjusting device in a light path are omitted, the complexity and space requirements of the system are reduced, a compact high-precision large-format exposure effect is realized, alignment between pixels of a spatial modulator and micro-elements of a micro-lens array is not needed, the influence of stray light is avoided, and the splicing problem under high-precision scanning exposure is solved.

Description

[Technical field]

[0001] The present invention relates to the technical field of projection exposure, and in particular to a projection exposure system. [Background technology]

[0002] The optical path of the current LDI (laser direct imaging) projection exposure optical system is basically composed of an illumination module, a spatial modulator module, a projection lens, and other parts, such as the prior art CN113655598A. This solution requires a homogenization and shaping design of the illumination light source, and the system optical path is complex and has a large volume. The prior art can also meet the needs of high-precision large-format exposure by adopting an optical path system of a microlens array device and a dual projection lens, such as CN101673056A. The optical path structure of this system is more complex, and the design and assembly are extremely difficult. In addition, there is also a two-stage optical path design using a microlens array device in the prior art. However, due to the lens distortion problem of the first imaging optical system, there will be misalignment between the light spot and the microlens, causing crosstalk and stray light problems between the microlens elements, affecting the contrast. At the same time, due to the lens distortion problem of the second imaging optical system and the actual production requirements for micron or even sub-micron stitching, the accuracy of adjusting the stitching error through the exposure method and the mechanism adjustment method is limited by the size of the light spot, resulting in high difficulty in compensating the micron-level stitching accuracy between the exposure areas.

[0003] In view of this, it is necessary to provide a new projection exposure system to overcome the above-mentioned defects. [Summary of the invention]

[0004] The object of the present invention is to provide a projection exposure system to solve the above technical problems.

[0005] In order to achieve the above-mentioned purpose, in a first aspect, the present invention provides a projection exposure system, comprising a self-luminous array component, a projection lens component and a workbench, wherein the projection lens component is arranged between the self-luminous array component and the workbench; the self-luminous array component comprises a self-luminous light source array and a shaping microlens array, wherein the shaping microlens array is located on one side of the light emitting surface of the self-luminous light source array, the self-luminous light source array is used to generate pixel light source, and the shaping microlens array is used to shape the light spot of the pixel light source and form an array light spot with uniform distribution; the array light spot passes through the projection lens component to project the light spot image corresponding to the array light spot onto the surface of the workpiece table, and the projection lens component is also used to adjust the light spot displacement to realize stitching error compensation.

[0006] In a preferred embodiment, the self-luminous light source array is one of VCSEL, LD array, LED array, and OLED.

[0007] In a preferred embodiment, the self-luminous light source array is connected to an integrated circuit switch, and the integrated circuit switch is used to control the brightness of the light spot of the self-luminous light source array.

[0008] In a preferred embodiment, the shaping microlens array is one of a cylindrical microlens, a gradient refractive index microlens, and an aspherical microlens, and the shaping microlens array is used to achieve long-axis and short-axis modulation shaping of the light spot to form a focused, circular array light spot.

[0009] In a preferred embodiment, the shaping microlens array is a single-layer structure or a multi-layer structure; the multi-layer structure of the shaping microlens array includes a first microlens array, a diffusion layer, a light-shielding layer, and a second microlens array, the first microlens array is close to the light-emitting surface of the self-luminous light source array, the diffusion layer is located between the first microlens array and the second microlens array, and the first microlens array and the second microlens array are symmetrically arranged, the light-shielding layer is arranged on the diffusion layer, and the light-shielding layer is provided with a light-through hole at the light path position of the self-luminous light source array.

[0010] In a preferred embodiment, the self-luminous array assembly further comprises a shading layer, the shading layer is arranged on a side of the shaping microlens array away from the self-luminous light source array, and the shading layer is provided with a light-transmitting hole at a focusing position of the light spot.

[0011] In a preferred embodiment, the projection lens assembly includes a dual telecentric projection lens and a parallel plate, wherein the parallel plate is located between the self-luminous array assembly and the dual telecentric projection lens, or the parallel plate is located between the dual telecentric projection lens and the workbench.

[0012] In a preferred embodiment, the parallel plate is connected to a driving device, and the driving device is used to drive the parallel plate and control the inclination of the parallel plate to adjust the light spot displacement to achieve stitching error compensation.

[0013] In a preferred embodiment, when the parallel plate adjusts the light spot displacement to achieve stitching error compensation, the following formula is used for calculation:

[0014]

[0015] Among them, Δy is the displacement of the light spot in the plane, t is the thickness of the parallel plate, θ is the tilt angle of the parallel plate, and n is the refractive index of the parallel plate.

[0016] In a preferred embodiment, a surface of the workpiece stage close to the projection lens assembly is placed with one of a photoresist material and a UV-curable 3D printing material.

[0017] Compared with the prior art, the projection exposure system provided by the present invention has a projection lens assembly arranged between the self-luminous array assembly and the workbench, the self-luminous array assembly includes a self-luminous light source array and a shaping microlens array, the shaping microlens array is located on one side of the light emitting surface of the self-luminous light source array, the self-luminous light source array is used to generate pixel light point light sources, the shaping microlens array is used to shape the light spots of the pixel light point light sources and form uniformly distributed array light spots, the array light spots pass through the projection lens assembly to project the light spot images corresponding to the array light spots onto the surface of the workpiece table, the projection lens assembly is also used to adjust the light spot displacement to achieve splicing error compensation, the present invention eliminates the lighting system and space adjustment devices in the optical path, reduces the complexity and space requirements of the system, achieves compact high-precision large-format exposure effects, reduces the difficulty of designing and debugging the system, does not require alignment between the spatial modulator pixels and the microelements of the microlens array, is free of stray light influence, and can solve the splicing problem under high-precision scanning exposure.

Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a light path diagram of the projection exposure system provided by the present invention.

[0020] Figure 2 A schematic diagram of a self-luminous array assembly in a projection exposure system provided by the present invention.

[0021] Figure 3 A schematic diagram of a self-luminous array assembly provided in accordance with another embodiment of the present invention.

[0022] Figure 4 Schematic diagram of the array light spot effect of the self-luminous array component.

[0023] Figure 5 An optical path diagram of a projection exposure system provided in yet another embodiment of the present invention.

[0024] Figure 6 Schematic diagram of the light spot effect when there is a stitching error in the exposure area and the stitching is misaligned.

[0025] Figure 7 Schematic diagram of adjusting the spot displacement for parallel plates to achieve stitching error compensation. [Specific implementation method]

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0027] See also Figure 1 , which is a light path diagram of the projection exposure system 100 provided by the present invention. The projection exposure system 100 provided by the present invention does not require an illumination system and a spatial adjustment device, greatly reduces the complexity of the light path and the system cost, and uses a micro-optical device to shape the light spot of the light-emitting array, replacing the complex illumination homogenization and shaping light path, and can also achieve a high-quality light spot array.

[0028] Please also read Figure 2 The projection exposure system 100 includes a self-luminous array component 10, a projection lens component 20 and a workbench 30, wherein the projection lens component 20 is disposed between the self-luminous array component 10 and the workbench 30. The self-luminous array component 10 includes a self-luminous light source array 11 and a shaping microlens array 12, wherein the shaping microlens array 12 is located on one side of a light emitting surface 111 of the self-luminous light source array 11, wherein the self-luminous light source array 11 is used to generate pixel light source, and the shaping microlens array 12 is used to shape the light spot of the pixel light source and form an array light spot with uniform distribution; the array light spot passes through the projection lens component 20 to project the light spot image corresponding to the array light spot onto the surface of the workbench 30, and the projection lens component 20 is also used to adjust the light spot displacement to realize stitching error compensation.

[0029] The self-luminous array component 10 is used to form an array of light spots corresponding to the binarized frame image pixels after image rasterization processing, and serves as the light source of the projection exposure system. The projection lens component 20 is used to project the array light spot image onto the surface of the work stage 30, and compensate for the two-dimensional stitching error of the light spot area to achieve micron-precision stitching of different exposure areas. The work stage 30 can be used to place exposure elements. The light emitted by the self-luminous array component 10 passes through the projection lens component 20, and the corresponding light spot image is projected onto the surface of the work stage 30 to complete the image transfer. The surface of the work stage 30 close to the projection lens component 20 can generally be placed with photoresist materials, UV-curing 3D printing materials, etc. to achieve image imaging and preservation.

[0030] The self-luminous light source array 11 can be one of VCSEL (Vertical Cavity Surface Emitting Laser), LD array (laser diode array), LED array (light emitting diode array), and OLED (organic light emitting diode). A number of self-luminous light sources are arranged in sequence to form a light source array, which is a self-luminous array component that can realize single-pixel light source switching. Specifically, the self-luminous light source array 11 is connected to an integrated circuit switch, and the integrated circuit switch is used to control the brightness of the light spot of the self-luminous light source array 11. That is, the present invention uses a self-luminous array device based on display panel manufacturing technology such as VCSEL / OLED as the light source of the system, which can realize the control of each light-emitting point pixel without using a spatial adjustment device (such as DMD), and realizes the control of the pixel point light spot and the superimposed energy control of the exposure surface.

[0031] The shaping microlens array 12 is a cylindrical microlens, a gradient refractive index microlens, an aspherical microlens, etc. The shaping microlens array is used to realize the long-axis and short-axis modulation shaping of the light spot to form a focused, circular array light spot. The light emitted by the self-luminous light source array component 11 passes through the shaping microlens array 12 to realize the long-axis and short-axis modulation shaping of the light spot to form a uniformly focused circular light spot.

[0032] In one embodiment, if Figure 2 As shown, the shaping microlens array 12 is a single-layer structure. The shaping microlens array 12 is formed by a plurality of microlenses arranged in sequence. Each microlens corresponds to a self-luminous light source. The light of each self-luminous light source forms a focused circular light spot after passing through the microlens.

[0033] In another embodiment, Figure 3 As shown, the shaping microlens array 12 is a multi-layer structure, and the shaping microlens array includes a first microlens array 121, a diffusion layer 122, a light-shielding layer 123, and a second microlens array 124. The first microlens array 121 is close to the light-emitting surface of the self-luminous light source array 11, and the diffusion layer 122 is located between the first microlens array 121 and the second microlens array 124, and the first microlens array 121 and the second microlens array 124 are symmetrically arranged. The light-shielding layer 123 is arranged on the diffusion layer 122, and the light-shielding layer 123 is provided with a light-through hole 1231 at the optical path position of the self-luminous light source array 111, that is, the light-shielding layer is arranged between the optical paths of adjacent self-luminous light sources, which can eliminate the influence of stray light after diffusion. The shaping microlens array 12 with a multi-layer structure can be realized by a micro-nano optical manufacturing process, and can further realize the homogenization and focusing of the light spot.

[0034] Please refer again Figure 2The self-luminous array component 10 further includes a light shielding layer 13, which is arranged on a side of the shaping microlens array 12 away from the self-luminous light source array 11. The light shielding layer 13 is provided with a light-transmitting hole 131 at the focusing position of the light spot. The light emitted by each self-luminous light source passes through a corresponding light-transmitting hole 131 after being focused by a corresponding microlens. The light shielding layer 13 suppresses the side lobes at the edge of the light spot position and limits the light spot position, and finally forms a light spot as shown in FIG. Figure 4 The array light spot shown, that is, the present invention uses micro-optical devices to shape the light spot of the light-emitting array, replacing the complex illumination homogenization and shaping light path, and can also achieve a high-quality light spot array. Specifically, the shaping microlens array 12 and the light shielding layer 13 can be manufactured by a micro-nano device processing process.

[0035] The projection lens assembly 20 includes a dual telecentric projection lens 201 and a parallel plate 24, wherein the parallel plate 24 is located between the self-luminous array assembly 10 and the dual telecentric projection lens 201. Figure 5 As shown, in other embodiments, the parallel plate 24 is located between the dual telecentric projection lens 201 and the workbench 30, that is, it is also feasible to place the parallel plate on the light source side in the dual telecentric projection optical path.

[0036] Specifically, the parallel plate 24 is connected to a driving device, which is used to drive the parallel plate 24 and control the inclination of the parallel plate to adjust the light spot displacement to achieve splicing error compensation. The parallel plate can be a flat glass. Figure 4 The light spot array after the binary image modulation is projected onto the imaging surface through the projection lens assembly 20. Figure 6 As shown, when there is a stitching error in the exposure area and the stitching is misaligned, the parallel plate 24 in the projection lens assembly 20 can be adjusted to electrically control the fine-tuning of the plane tilt to compensate for the stitching error. Figure 7 As shown in the figure, when the parallel plate adjusts the light spot displacement to compensate for the stitching error, the displacement of the light spot in the plane is calculated using the following formula:

[0037]

[0038] Wherein, Δy is the displacement of the light spot in the plane, that is, the displacement of the light spot in the vertical direction, t is the thickness of the parallel plate, that is, the thickness of the parallel plate in the vertical direction of its surface, θ is the inclination angle of the parallel plate, specifically, when the surface of the parallel plate is perpendicular to the horizontal plane, the parallel plate is not inclined, θ is 0°, when the parallel plate is inclined, the vertical direction of the parallel plate surface forms an angle θ with the horizontal plane, θ is the inclination angle of the parallel plate, and n is the refractive index of the parallel plate.

[0039] For example, if t=2mm, θ=0.1°, and the refractive index of flat glass n=1.46, then Δy=1.1μm, which can achieve micron-level micro-stitching modulation between exposure areas. Therefore, the present invention adopts inclined parallel flat plate elements to achieve two-way stitching compensation of the exposure field under the condition of high-precision exposure analysis, and the compensation accuracy can reach the micron or even sub-micron level, solving the stitching problem under high-precision scanning exposure.

[0040] The double telecentric projection lens 201 includes a first telecentric lens 21 close to the self-luminous array assembly 10, a second telecentric lens 22 close to the workbench 30, and an aperture stop 23 located between the first telecentric lens 21 and the second telecentric lens. The double telecentric optical path is usually a symmetrical structure, which places the aperture stop in the middle of the optical system. This can have the advantages of both the object-side telecentric optical path and the image-side telecentric optical path. The main light rays of the object and image sides are incident and emitted parallel to the optical axis, which can improve the resolution of the system measurement. The parallel light emission can stabilize the magnification, and the parallel light incidence can effectively deepen the depth of field of the measurement.

[0041] In summary, the beneficial effects of the projection exposure system 100 provided by the present invention are:

[0042] 1) The present invention adopts a self-luminous light source array device, and can directly use a micro-optical shaping scheme on the light-emitting surface of the light-emitting array to achieve a light spot array effect, which can eliminate the lighting system and space adjustment devices in the light path, reduce the complexity and space requirements of the system, and achieve a compact, high-precision, large-format exposure effect, while reducing the difficulty of designing and debugging the system.

[0043] 2) The present invention uses a self-luminous light source array device, which can control the brightness of the light spot through an integrated circuit switch. Since there is no need to use a spatial modulator, there is no need to align the spatial modulator pixels with the microlens array microelements, and there is no stray light influence.

[0044] 3) The present invention adopts a self-luminous light source array device, which can adjust the two-dimensional spot displacement of the light spot on the imaging surface by electrically adjusting the parallel plate angle to fine-tune the exposure area splicing. The compensation accuracy can reach the micron or even sub-micron level, solving the splicing problem under high-precision scanning exposure.

[0045] 4) The present invention adopts a self-luminous light source array and a micro-optical device to achieve the adjustment of the light spot. Compared with the three-stage lighting light path design, it has the following advantages: compact structure, simple light path, and by adjusting the light spot size of the light spot array, a higher exposure resolution can be achieved than the pixel of the spatial adjustment device.

[0046] 5) The present invention adopts a self-luminous light source array and a micro-optical device to adjust the light spot, and at the same time adds a parallel plate element in the double telecentric optical path to realize the splicing adjustment. The optical path design structure is greatly reduced, reducing the complexity of the system structure and the difficulty of debugging. The parallel plate element is used to adjust the splicing, and the format splicing effect can be dynamically adjusted in real time. Compared with the light spot switch to adjust the splicing effect, there is no need for complex image processing algorithms, which reduces the requirements for the performance of data processing devices, and can also be adjusted in real time according to the exposure effect.

[0047] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A projection exposure system, characterized in that: It includes a self-luminous array component, a projection lens component and a workbench, wherein the projection lens component is arranged between the self-luminous array component and the workbench; the self-luminous array component includes a self-luminous light source array and a shaping microlens array, wherein the shaping microlens array is located on one side of the light emitting surface of the self-luminous light source array, the self-luminous light source array is used to generate pixel luminous point light sources, and the shaping microlens array is used to shape the light spots of the pixel luminous point light sources and form uniformly distributed array light spots; the array light spots pass through the projection lens component to project the light spot images corresponding to the array light spots onto the surface of the workpiece table, and the projection lens component is also used to adjust the light spot displacement to achieve stitching error compensation.

2. The projection exposure system according to claim 1, characterized in that The self-luminous light source array is one of VCSEL, LDarray, LED array and OLED.

3. The projection exposure system according to claim 1, characterized in that The self-luminous light source array is connected to an integrated circuit switch, and the integrated circuit switch is used to control the brightness of the light spot of the self-luminous light source array.

4. The projection exposure system according to claim 1, characterized in that The shaping microlens array is one of a cylindrical microlens, a gradient refractive index microlens, and an aspherical microlens. The shaping microlens array is used to achieve long-axis and short-axis modulation shaping of the light spot to form a focused, circular array light spot.

5. The projection exposure system according to claim 1, characterized in that The shaping microlens array is a single-layer structure or a multi-layer structure; the shaping microlens array with a multi-layer structure includes a first microlens array, a diffusion layer, a light-shielding layer, and a second microlens array, the first microlens array is close to the light-emitting surface of the self-luminous light source array, the diffusion layer is located between the first microlens array and the second microlens array, and the first microlens array and the second microlens array are symmetrically arranged, the light-shielding layer is arranged on the diffusion layer, and the light-shielding layer is provided with a light-through hole at the light path position of the self-luminous light source array.

6. The projection exposure system according to claim 1, characterized in that The self-luminous array component further comprises a light shielding layer, which is arranged on a side of the shaping microlens array away from the self-luminous light source array, and the light shielding layer is provided with a light-transmitting hole at the focusing position of the light spot.

7. The projection exposure system according to claim 1, characterized in that The projection lens assembly includes a dual telecentric projection lens and a parallel plate. The parallel plate is located between the self-luminous array assembly and the dual telecentric projection lens, or the parallel plate is located between the dual telecentric projection lens and the workbench.

8. The projection exposure system according to claim 7, characterized in that The parallel plates are connected to a driving device, and the driving device is used to drive the parallel plates and control the inclination of the parallel plates to adjust the light spot displacement to achieve splicing error compensation.

9. The projection exposure system according to claim 8, characterized in that When the parallel plate adjusts the light spot displacement to achieve stitching error compensation, the following formula is used for calculation: Among them, Δy is the displacement of the light spot in the plane, t is the thickness of the parallel plate, θ is the tilt angle of the parallel plate, and n is the refractive index of the parallel plate.

10. The projection exposure system according to any one of claims 1 to 9, characterized in that: A surface of the workpiece platform close to the projection lens assembly is provided with one of a photoresist material and an ultraviolet curing 3D printing material.

Images