Alignment system of an exposure apparatus, exposure apparatus, and exposure method

Abstract

The application relates to the field of display panel processing, and discloses an alignment system of an exposure device, the exposure device and an exposure method, the alignment system of the exposure device comprises a mask plate, an alignment substrate and a moving alignment structure, the mask plate is provided with a first alignment mark, the surface of the alignment substrate is sequentially provided with a first metal layer, a second metal layer and a photoresist layer, the first metal layer has a main body part and a hollow part, the hollow part comprises non-connected hollow patterns extending along the horizontal direction, two adjacent hollow patterns are separated by the main body part, and the hollow part forms a second alignment mark corresponding to the first alignment mark. By arranging the hollow alignment mark on the alignment substrate, the photoresist layer forms a concave-convex surface on the surface of the area, when the light of the exposure device irradiates the concave-convex surface, the alignment mark area and the surrounding area form an effective reflection difference, effective alignment calculation is realized, and the exposure device can realize automatic alignment.

Description

Technical Field

[0001] This invention relates to the field of display panel processing, and more particularly to an alignment system, exposure equipment, and exposure method for an exposure apparatus. Background Technology

[0002] With the booming development of the current electronics industry, photolithography machines are widely used in many fields, mainly including chip manufacturing, packaging technology, LED production, touch panel manufacturing, microelectromechanical systems (MEMS), bioelectronics, and flexible electronics. For example... Figure 1 and Figure 2 As shown, the photolithography alignment system is its core component, and one typical implementation principle is as follows: A square-shaped CCD overlay mark 11 is provided on the mask 10, and a cross-shaped CCD reference mark 21 is provided on the substrate 20. The illumination system 30 projects the marks on the substrate 20 and the mask onto the CCD sensor of the exposure machine. Due to the difference in material properties between the reference mark and the substrate 20, the intensity of reflected light in their respective areas will show a significant difference. The exposure machine forms a black-and-white contrast field by detecting the difference in reflected light intensity, generating characteristic peak signals in the X and Y directions to achieve precise positioning. The specific alignment process is as follows: The automatic calculation system of the exposure machine first calculates the two center positions in the Y direction [(y1+y2) / 2+(y3+y4) / 2] / 2 and (y5+y6) / 2, and then compares whether the deviation values ​​of these two centers are within the preset tolerance range. If they exceed the allowable range, the servo stage will adsorb the substrate 20 for fine-tuning until the deviation meets the requirements. The alignment adjustment in the X direction adopts the same principle. When the deviations in the X and Y directions and the rotation angle θ all meet the set standards, the system completes automatic alignment and executes the exposure process.

[0003] In practical applications, photolithography is typically used in conjunction with coating processes. The substrate 20 often features a composite stacked structure, and the reference mark may be covered by a transparent or opaque film layer, with film thicknesses typically ranging from 100μm to 5000μm. Taking a MetalMesh touch sensor as an example, its structure comprises two metal film layers 40, with the touch pattern formed through a "coating first, photolithography later" process. During the photolithography stage, a layer of photoresist needs to be coated onto the second metal film. However, misalignment of the two metal film layers 40 directly affects the product's visual appearance. If direct alignment of the two metal film layers 40 can be achieved, rather than relying on indirect alignment via the photoresist layer, the overall alignment accuracy can be effectively improved.

[0004] like Figure 3As shown, in the photolithography process, a stepped structure forms at the reference mark position, with a wider and thinner peripheral area. Due to surface tension and fluidity, the photoresist surface gradually becomes smoother and more uniform; this effect is called leveling. Leveling directly affects the thickness uniformity, edge morphology, and subsequent exposure and development quality of the photoresist film. When incident light (R) is reflected by the photoresist and metal layer, the reflected light characteristics of different regions are as follows:

[0005] Since the reflective medium is the same and the film thickness is almost uniform, the reflected light intensity in each region satisfies:

[0006] Reference Mark region: R1 + R2 = R

[0007] Left region: R3 + R4 = R

[0008] Right side region: R5 + R6 = R

[0009] At this point, R2 = R3 = R5, and R1 = R4 = R6, resulting in highly consistent composite reflected light intensity (R) across all regions. Consequently, when the exposure machine collects specular reflected light, it cannot detect significant differences in reflectance values ​​between different locations, making it difficult to generate sufficient black-and-white field contrast, ultimately leading to the failure of the automatic alignment process. Summary of the Invention

[0010] This invention aims to solve at least one problem in the prior art. To this end, this invention proposes an alignment system, an exposure device, and an exposure method for an exposure apparatus. The alignment system of the exposure apparatus sets alignment marks with cutouts on an alignment substrate. The leveling effect of the photoresist layer on the surface of this area creates an uneven surface. When light from the exposure apparatus illuminates this uneven surface, an effective reflection difference is formed between the alignment mark area and the surrounding area, thereby achieving effective alignment calculation and enabling the exposure apparatus to complete automatic alignment.

[0011] According to a first aspect of the present invention, an alignment system of an exposure apparatus includes a photomask, an alignment substrate, and a movable alignment structure. The photomask has a first alignment mark. The alignment substrate has a first metal layer, a second metal layer, and a photoresist layer sequentially disposed on its surface. The first metal layer has a main body and a cutout portion. The main body surrounds the cutout portion. The cutout portion includes at least two non-connected cutout patterns extending horizontally. Adjacent cutout patterns are separated by the main body. The cutout portion constitutes a second alignment mark corresponding to the first alignment mark. The movable alignment structure is used to control the alignment substrate to move relative to the photomask according to a received control signal.

[0012] As can be seen, since the second alignment mark is a hollow pattern, after the second metal layer and photoresist layer cover the stepped area formed by the second alignment mark, the leveling effect of the photoresist layer on its surface is poor, which will form an uneven surface. When the light from the exposure equipment shines on the uneven surface, it will form diffuse reflection on the surface, thereby forming an effective reflection difference between the second alignment mark area and the surrounding area, thus forming a detectable peak, realizing effective alignment calculation, and enabling the exposure equipment to complete automatic alignment.

[0013] According to another embodiment of the present invention, the length of a single hollowed-out pattern in the horizontal direction is 50-200 μm and the width is 5-20 μm.

[0014] According to another embodiment of the present invention, the hollowed-out pattern is one or more of a square, rectangle, strip, or polygon.

[0015] According to another embodiment of the present invention, the thickness of the first metal layer and / or the second metal layer is 0.01-0.5 μm.

[0016] According to another embodiment of the present invention, the thickness of the photoresist layer is 1-10 μm.

[0017] According to another embodiment of the present invention, the second metal layer covers the main body and the hollowed-out portion of the first metal layer.

[0018] According to another embodiment of the present invention, the photoresist layer covers the surface of the second metal layer.

[0019] An exposure apparatus according to a second aspect of the present invention includes a light source system and an alignment system for the exposure apparatus described in any of the preceding claims.

[0020] An exposure method for an alignment system employing any one of the above-described exposure apparatuses according to a third aspect of the present invention specifically includes the following steps:

[0021] A mask template is provided, on which a first alignment mark is formed;

[0022] A matching substrate is provided, and a first metal layer is formed on the surface of the matching substrate;

[0023] A cutout is formed on the surface of the first metal layer, and the cutout constitutes a second alignment mark corresponding to the first alignment mark.

[0024] A second metal layer is formed on the surface of the first metal layer, and the second metal layer covers the second alignment mark;

[0025] A photoresist layer is formed on the surface of the second metal layer;

[0026] A light source system is provided, which projects the first alignment mark and the second alignment mark on the photomask and the alignment substrate onto an exposure device for alignment.

[0027] Exposure is performed based on the aligned photomask and the aligned substrate.

[0028] According to another embodiment of the present invention, the first metal layer has a main body and a hollowed-out portion, the main body being disposed around the hollowed-out portion, the hollowed-out portion including at least two non-connected hollowed-out patterns extending in a horizontal direction, the two adjacent hollowed-out patterns being separated by the main body, and the hollowed-out portion constituting a second alignment mark corresponding to the first alignment mark.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention discloses an alignment system, an exposure device, and an exposure method for an exposure apparatus. The alignment system of the exposure apparatus includes a photomask, an alignment substrate, and a movable alignment structure. A first alignment mark is provided on the photomask. A first metal layer, a second metal layer, and a photoresist layer are sequentially disposed on the surface of the alignment substrate. The first metal layer has a main body and a cutout portion. The main body is disposed around the cutout portion. The cutout portion includes at least two non-connected cutout patterns extending in a horizontal direction. Adjacent cutout patterns are separated by the main body. The cutout portion constitutes a second alignment mark corresponding to the first alignment mark. The movable alignment structure is used to control the alignment substrate to move relative to the photomask according to a received control signal. As can be seen, since the second alignment mark is a hollow pattern, after the second metal layer and photoresist layer cover the stepped area formed by the second alignment mark, the leveling effect of the photoresist layer on its surface is poor, which will form an uneven surface. When the light from the exposure equipment shines on the uneven surface, it will form diffuse reflection on the surface, thereby forming an effective reflection difference between the second alignment mark area and the surrounding area, thus forming a detectable peak, realizing effective alignment calculation, and then the exposure equipment can complete automatic alignment.

[0031] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0032] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0033] Figure 1 This is a schematic diagram of an embodiment of an exposure device in the prior art;

[0034] Figure 2A schematic diagram of an embodiment of CCD overlay marking in an exposure device in the prior art;

[0035] Figure 3 Another schematic diagram of an embodiment of an exposure device in the prior art;

[0036] Figure 4 A schematic diagram of an embodiment of the first metal layer of the alignment system of the exposure apparatus provided in this application;

[0037] Figure 5 A schematic diagram of an embodiment of the second alignment mark of the alignment system of the exposure apparatus provided in this application;

[0038] Figure 6 Another schematic diagram of an embodiment of the alignment system of the exposure apparatus provided in this application;

[0039] Figure 7 Flowcharts of embodiments of the exposure method provided in this application;

[0040] The markings in the diagram mean:

[0041] 10. Mask; 11. Square-shaped CCD overlay mark; 20. Substrate;

[0042] 21. Cross-shaped CCD reference mark; 30. Illumination system; 40. Metallic film layer;

[0043] 100. Mask template; 110. First alignment mark;

[0044] 200, Alignment substrate; 210, First metal layer; 211, Main body; 212, Cutout portion;

[0045] 213. Second alignment mark;

[0046] 220. Second metal layer; 230. Photoresist layer. Detailed Implementation

[0047] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0048] In the description of this invention, it should be understood that features specified as "first" or "second" may explicitly or implicitly include one or more of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] To illustrate the alignment system, exposure equipment, and exposure method of the exposure apparatus provided in this application, the following detailed description is provided in conjunction with the accompanying drawings and textual descriptions of the embodiments.

[0051] The following is for reference. Figures 4-6 The alignment system of the exposure apparatus according to a first aspect embodiment of the present invention is described, specifically including a mask 100, an alignment substrate 200, and a movable alignment structure (not shown in the figure). Specifically, a first alignment mark 110 is provided on the mask 100; further, a first metal layer 210, a second metal layer 220, and a photoresist layer 230 are sequentially provided on the surface of the alignment substrate 200. The first metal layer 210 has a main body portion 211 and a cutout portion 212. The main body portion 211 is disposed around the cutout portion 212. The cutout portion 212 includes at least two non-connected cutout patterns extending in a horizontal direction. Two adjacent cutout patterns are separated by the main body portion 211. The cutout portion 212 constitutes a second alignment mark 213 corresponding to the first alignment mark 110; further, the movable alignment structure is used to control the alignment substrate 200 to move relative to the mask 100 according to a received control signal. Therefore, this solution sets the second alignment mark 213 as a hollow pattern, so that after the second metal layer 220 and the photoresist layer 230 cover the stepped area formed by the second alignment mark 213, the leveling effect of the photoresist layer 230 on the surface of the second alignment mark 213 is poor, and the surface of the second alignment mark 213 will form an uneven surface. When the light from the exposure equipment shines on the uneven surface, diffuse reflection will be formed on the surface, thereby forming an effective reflection difference between the area of ​​the second alignment mark 213 and the surrounding area, thus forming a detectable peak, realizing effective alignment calculation, and enabling the exposure equipment to complete automatic alignment.

[0052] It should be noted that, as Figure 6 As shown, after light undergoes incident reflection:

[0053] On a flat surface, R = R3 + R4 = R5 + R6

[0054] On an uneven surface, R = R1 + R7

[0055] Therefore, when the exposure equipment collects specular reflected light, the reflection at the second alignment mark 213 position is R1 < R3 + R4 = R5 + R6. This creates an effective reflection difference, which can produce peaks y5 / y6. The automatic calculation system of the exposure equipment first calculates the two center positions in the Y direction [(y1 + y2) / 2 + (y3 + y4) / 2] / 2 and (y5 + y6) / 2, and then compares whether the deviation values ​​of these two centers are within the preset tolerance range. The alignment adjustment in the X direction uses the same principle. When the deviations in the X and Y directions and the rotation angle θ all meet the set standards, the system completes automatic alignment, preparing for the subsequent exposure process.

[0056] It should be noted that the second alignment mark 213 can be a hollowed-out "cross" shape, which makes it easy to correspond with the first alignment mark 110.

[0057] It should be noted that the cutout pattern can be a continuous, integrated pattern or a combination of multiple separate patterns.

[0058] It should be noted that the cutout pattern can be regular or irregular.

[0059] It should be noted that an insulating layer (not shown in the figure) is provided between the first metal layer 210 and the second metal layer 220 to achieve electrical isolation between the first metal layer 210 and the second metal layer 220.

[0060] According to one embodiment of the present invention, such as Figures 4-6 As shown, the length of a single hollow pattern along the horizontal direction is 50-200μm and the width is 5-20μm. It can be understood that the length of a single hollow pattern is between 50-200μm and the width is between 5-20μm, which allows the size of the second alignment mark 213 composed of the hollow patterns to meet the alignment requirements, thereby achieving rapid alignment.

[0061] According to one embodiment of the present invention, such as Figures 4-6 As shown, the cutout pattern can be one or more of the following: square, rectangle, strip, or polygon. It can be understood that the cutout pattern is preferably a regular shape, which is convenient for processing and generation.

[0062] According to one embodiment of the present invention, such as Figures 4-6 As shown, the thickness of the first metal layer 210 and / or the second metal layer 220 is 0.01-0.5μm. It can be understood that when the first metal layer 210 and the second metal layer 220 are stacked, their thickness of 0.01-0.5μm can match the thickness of the dielectric layer, ensure surface flatness, and avoid problems such as step coverage in subsequent photolithography or deposition processes.

[0063] According to one embodiment of the present invention, such as Figures 4-6 As shown, the thickness of the photoresist layer 230 is 1-10 μm. It is understandable that controlling the thickness of the photoresist is one of the key factors affecting the pattern transfer accuracy and the success or failure of the process. Therefore, when the thickness of the photoresist layer 230 is 1-10 μm, the light scattering effect can be reduced, the clarity of the pattern edge can be improved, and the problem of lateral scattering of light such as "standing wave effect" or "halo effect" in the photoresist layer 230 caused by excessive photoresist thickness can also be avoided.

[0064] According to one embodiment of the present invention, such as Figures 4-6 As shown, the second metal layer 220 covers the main body 211 and the hollowed-out portion 212 of the first metal layer 210. It can be understood that the second metal layer 220 will fill the hollowed-out portion 212 during the manufacturing process, thereby achieving full coverage of the surface and hollowed-out area of ​​the first metal layer 210.

[0065] According to one embodiment of the present invention, such as Figures 4-6 As shown, the photoresist layer 230 covers the surface of the second metal layer 220, thereby enabling high-precision pattern transfer in subsequent photolithography processes.

[0066] The following describes an exposure apparatus according to a second aspect embodiment of the present invention. Based on the same inventive concept, this application provides an exposure apparatus including a light source system (not shown in the figure), the alignment system of the above-mentioned exposure apparatus, and an exposure chamber (not shown in the figure). Specifically, a support stage (not shown in the figure) for supporting the photomask 100 is provided in the exposure chamber. Since the exposure apparatus includes the alignment system of the above-mentioned exposure apparatus, the exposure apparatus has the same beneficial technical effects as the alignment system of the above-mentioned exposure apparatus. That is, by setting the second alignment mark 213 as a hollow pattern, after the second metal layer 220 and the photoresist layer 230 cover the stepped area formed by the second alignment mark 213, the leveling effect of the photoresist layer 230 at the surface of the second alignment mark 213 is poor, and the surface of the second alignment mark 213 will form an uneven surface. When the light of the exposure apparatus irradiates the uneven surface, diffuse reflection will be formed on the surface, thereby forming an effective reflection difference between the area of ​​the second alignment mark 213 and the surrounding area, thereby forming a detectable peak, realizing effective alignment calculation, and thus the exposure apparatus can complete automatic alignment.

[0067] Specifically, the exposure equipment includes a light source system and an alignment system for the exposure equipment.

[0068] The following is for reference. Figure 7 An exposure method according to a third aspect embodiment of the present invention, employing an exposure apparatus of the first aspect embodiment, is described, specifically including the following steps:

[0069] Step S100: Provide a mask template 100 and form a first alignment mark 110 on the mask template 100.

[0070] Specifically, the shape of the first alignment mark 110 can be square.

[0071] Step S200: Provide a registration substrate 200 and form a first metal layer 210 on the surface of the registration substrate 200.

[0072] Specifically, the first metal layer 210 can be a metal mesh layer.

[0073] Step S300: A hollow portion 212 is formed on the surface of the first metal layer 210, and the hollow portion 212 constitutes a second alignment mark 213 corresponding to the first alignment mark 110.

[0074] Specifically, the second alignment mark 213 can be a hollowed-out "cross" shape, which makes it easy to correspond with the first alignment mark 110.

[0075] Step S400: A second metal layer 220 is formed on the surface of the first metal layer 210, and the second metal layer 220 covers the second alignment mark 213.

[0076] Specifically, the second metal layer 220 can be a metal mesh layer.

[0077] Step S500: A photoresist layer 230 is formed on the surface of the second metal layer 220.

[0078] Specifically, the thickness of the photoresist layer 230 is 1-10 μm.

[0079] Step S600: A light source system is provided, which projects the first alignment mark 110 and the second alignment mark 213 on the mask 100 and the alignment substrate 200 onto the exposure device for alignment.

[0080] Step S700: Exposure is performed based on the aligned mask 100 and the alignment substrate 200.

[0081] Therefore, by setting the second alignment mark 213 as a cutout portion 212, after the second metal layer 220 and the photoresist layer 230 cover the stepped area formed by the second alignment mark 213, the leveling effect of the photoresist layer 230 on the surface of the second alignment mark 213 is poor, and the surface of the second alignment mark 213 will form an uneven surface. When the light from the exposure equipment shines on the uneven surface, diffuse reflection will be formed on the surface, thereby forming an effective reflection difference between the area of ​​the second alignment mark 213 and the surrounding area, thereby forming a detectable peak, realizing effective alignment calculation, and thus the exposure equipment can complete automatic alignment.

[0082] According to one embodiment of the present invention, such as Figures 4-5 As shown, the first metal layer 210 has a main body portion 211 and a hollow portion 212. The main body portion 211 is disposed around the hollow portion 212. The hollow portion 212 includes at least two non-connected hollow patterns extending in the horizontal direction. The two adjacent hollow patterns are separated by the main body portion 211. The hollow portion 212 constitutes a second alignment mark 213 corresponding to the first alignment mark 110.

[0083] It should be noted that the length of a single hollowed-out pattern along the horizontal direction is 50-200μm and the width is 5-20μm, so that the size of the second alignment mark 213 composed of hollowed-out patterns meets the alignment requirements, thereby achieving rapid alignment.

[0084] It should be noted that the cutout pattern can be one or more of the following: square, rectangular, strip, or polygonal, to facilitate processing and generation.

[0085] The above-described alignment system, exposure equipment, and exposure method for the exposure device provided in this application are preferred embodiments and should not be construed as limiting the scope of protection of this application. Those skilled in the art should know that various improvements or substitutions can be made without departing from the concept of this application, and all improvements or substitutions should be within the scope of protection of this application, that is, the scope of protection of this application should be determined by the claims.

[0086] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

Claims

1. A alignment system for an exposure apparatus, characterized in that, include: A mask template, on which a first alignment mark is provided; The alignment substrate has a first metal layer, a second metal layer and a photoresist layer sequentially disposed on its surface. The first metal layer has a main body and a cutout portion. The main body is disposed around the cutout portion. The cutout portion includes at least two non-connected cutout patterns extending in a horizontal direction. Two adjacent cutout patterns are separated by the main body. The cutout portion constitutes a second alignment mark corresponding to the first alignment mark. A movable alignment structure is provided, wherein the movable alignment structure is used to control the alignment substrate to move relative to the mask template according to a received control signal.

2. The alignment system of the exposure apparatus as described in claim 1, characterized in that, The length of a single hollowed-out pattern along the horizontal direction is 50-200μm, and the width is 5-20μm.

3. The alignment system of the exposure apparatus as described in claim 1, characterized in that, The cutout pattern can be one or more of the following: square, rectangular, strip, or polygonal.

4. The alignment system of the exposure apparatus as described in claim 1, characterized in that, The thickness of the first metal layer and / or the second metal layer is 0.01-0.5 μm.

5. The alignment system of the exposure apparatus as described in claim 1, characterized in that, The thickness of the photoresist layer is 1-10 μm.

6. The alignment system of the exposure apparatus as described in claim 1, characterized in that, The second metal layer covers the main body and the hollowed-out portion of the first metal layer.

7. The alignment system of the exposure apparatus as described in claim 1, characterized in that, The photoresist layer covers the surface of the second metal layer.

8. An exposure apparatus, characterized in that, It includes a light source system and an alignment system for the exposure apparatus according to any one of claims 1-7.

9. An exposure method using an alignment system of the exposure apparatus according to any one of claims 1-7, characterized in that, include: A mask template is provided, on which a first alignment mark is formed; A matching substrate is provided, and a first metal layer is formed on the surface of the matching substrate; A cutout is formed on the surface of the first metal layer, and the cutout constitutes a second alignment mark corresponding to the first alignment mark. A second metal layer is formed on the surface of the first metal layer, and the second metal layer covers the second alignment mark; A photoresist layer is formed on the surface of the second metal layer; A light source system is provided, which projects the first alignment mark and the second alignment mark on the photomask and the alignment substrate onto an exposure device for alignment. Exposure is performed based on the aligned photomask and the aligned substrate.

10. The exposure method as described in claim 9, characterized in that, The first metal layer has a main body and a cutout portion. The main body is arranged around the cutout portion. The cutout portion includes at least two non-connected cutout patterns extending in a horizontal direction. Two adjacent cutout patterns are separated by the main body. The cutout portion constitutes a second alignment mark corresponding to the first alignment mark.

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