Exposure apparatus and combined reticle

Abstract

The embodiment of the present application discloses an exposure device and a combined mask thereof, wherein the combined mask comprises a first metal layer, a plurality of first light transmission holes are formed in the first metal layer; a second metal layer is arranged opposite to the first metal layer, a plurality of second light transmission holes are formed in the second metal layer, and the second light transmission holes are arranged corresponding to the first light transmission holes along an optical axis. The present application filters the oblique light in the light beam through the multiple metal layers, ensures that all the light rays in the light beam propagate along the optical axis direction, increases the parallelism of all the light rays in the light beam, makes the dispersion of the laser beam lower, and further enables the laser beam to perform accurate etching under a large gap. The technical problem that the parallelism of the light path of the current proximity exposure machine is not high in the prior art, the formed laser beam is relatively dispersed, and a lower gap needs to be used is solved.

Description

Technical Field

[0001] This application relates to the field of display technology, and more specifically to an exposure device and its combined photomask. Background Technology

[0002] Photolithography is a technique for creating precise, minute, and complex patterns on thin film surfaces or metals, and it is a crucial manufacturing technology, especially in the semiconductor industry. The photolithography process is quite complex, with exposure being the most critical step. Exposure requires materials such as a photomask, a light source, and a substrate.

[0003] In photolithography, light must pass through the photomask and concentrate on the photoresist, requiring a high degree of parallelism in the resulting optical path. As process capabilities increase, the precision requirements for photolithography areas also rise. However, current proximity-type exposure machines often suffer from low optical path parallelism, resulting in a relatively dispersed laser beam. Therefore, a smaller gap is needed to bring the photomask closer to the substrate for etching, reducing beam dispersion. Within a single exposure cycle, the gap needs to decrease from large to small; a smaller gap results in slower movement. If the gap is too small, it can extend the fabrication time by approximately 40%, leading to significant throughput loss. Furthermore, a small gap increases the risk of scratching the photomask. Summary of the Invention

[0004] This application provides an exposure device and its combined photomask, which can solve the technical problem in the prior art where the optical path parallelism of the current proximity exposure machine is not high, resulting in a relatively dispersed laser beam, requiring the use of a lower gap.

[0005] This application provides a combined photomask, including:

[0006] A first photomask, the first photomask comprising a first metal layer, the first metal layer having a plurality of first light-transmitting holes;

[0007] The second photomask includes a second metal layer, which is disposed opposite to the first metal layer. The second metal layer has a plurality of second light-transmitting holes, which are disposed along the optical axis and correspond to the first light-transmitting holes. The aperture of the first light-transmitting hole is not larger than the aperture of the second light-transmitting hole.

[0008] Both the second photomask and the first photomask reduce the beam angle of the laser. During etching, the laser passes through the second photomask first and then through the first photomask.

[0009] In some embodiments of this application, the first photomask further includes a first light-transmitting layer, and the first metal layer is attached to one side of the first light-transmitting layer;

[0010] The second photomask is attached to the side of the first light-transmitting layer opposite to the first metal layer. The second photomask also includes a second light-transmitting layer, and the second metal layer is attached to one side of the second light-transmitting layer and is attached to the first light-transmitting layer.

[0011] In some embodiments of this application, an adhesive layer is further provided between the first photomask and the second photomask, the adhesive layer bonding the first photomask and the second photomask together.

[0012] In some embodiments of this application, the adhesive layer comprises:

[0013] A bonding layer is attached to the side of the second metal layer that faces away from the second light-transmitting layer.

[0014] A liquid adhesive layer is applied to the side of the solid adhesive layer that faces away from the second metal layer.

[0015] In some embodiments of this application, the first light-transmitting hole and the second light-transmitting hole are arranged concentrically.

[0016] In some embodiments of this application, the overall thickness of the combined photomask is greater than 12 mm and less than 14 mm.

[0017] In some embodiments of this application, the spacing between the first metal layer and the second metal layer is between 1 mm and 13 mm.

[0018] Accordingly, embodiments of this application also provide an exposure apparatus, including:

[0019] The combined photomask as described above;

[0020] A support platform is disposed on the side of the first metal layer away from the second metal layer, and the support platform is used to support the material to be etched.

[0021] A light source is disposed on the side of the combined photomask opposite to the support platform. The laser emitted by the light source passes through the first light-transmitting hole and the second light-transmitting hole to form an etching beam to etch the material to be etched. The angle between the light rays in the etching beam and the optical axis is less than 0.5 degrees.

[0022] In some embodiments of this application, the laser emitted by the light source passes through the second light-transmitting hole to form a transition beam along the optical axis, and the transition beam passes through the first light-transmitting hole to form an etching beam; the beam angle of the transition beam is greater than the beam angle of the etching beam.

[0023] In this embodiment, two metal layers are used to filter the laser emitted from the light source twice. During each filtering, light rays with excessive angles to the optical axis are blocked by the metal layers and cannot pass through the light-transmitting aperture, thus ensuring that all light rays in the beam propagate along the optical axis. This increases the parallelism of the light rays within the beam, resulting in lower laser beam dispersion and enabling precise etching even with large gaps. This solves the technical problem in existing proximity exposure machines where the optical path parallelism is not high, leading to a more dispersed laser beam and requiring the use of smaller gaps. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the exposure apparatus provided in the embodiments of this application;

[0026] Figure 2 This is a simplified structural diagram of the combined photomask provided in the embodiments of this application;

[0027] Figure 3 This is a schematic diagram of the structure of the combined photomask provided in the embodiments of this application;

[0028] Figure 4 This is a schematic diagram of the adhesive layer structure provided in the embodiments of this application;

[0029] Figure 5 This is a structural dimension diagram of the combined photomask provided in the embodiments of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 10. Frame; 20. Light source; 30. Combined photomask; 40. Support platform; 50. Material to be etched; 100. First photomask; 200. Second photomask; 300. Adhesive layer; 110. First metal layer; 120. First light-transmitting layer; 130. First light-transmitting hole; 210. Second metal layer; 220. Second light-transmitting layer; 230. Second light-transmitting hole; 310. Solid adhesive layer; 320. Liquid adhesive layer. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0033] This application provides an exposure apparatus and its combined photomask 30. Detailed descriptions follow. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0034] This application provides an exposure apparatus that can be used for photolithography processing of array substrates, color filter substrates, driver integrated circuits, and chips.

[0035] Please see Figure 1 The exposure apparatus includes a frame 10, a light source 20, a combined photomask 30, and a support platform 40. The frame 10 is the main body of the exposure apparatus, and the light source 20, combined photomask 30, and support platform 40 are all connected to the frame 10 in different ways. For example, the combined photomask 30 can be connected to the frame 10 via a support frame, a fixed table, or a gripper. The light source 20 is positioned above the combined photomask 30 to emit a laser for etching. The support platform 40 is positioned below the combined photomask 30 to support the material to be etched 50, which includes a substrate and photoresist coated on the substrate. During etching, the laser emitted by the light source 20 passes through the light-transmitting holes of the photomask and is projected onto the photoresist, thus initiating the etching of the substrate.

[0036] Please refer to the following: Figure 2 The aforementioned combined photomask 30 includes a first photomask 100 and a second photomask 200. The first photomask 100 is disposed at the bottom facing the support platform 40, and the second photomask 200 is disposed at the top facing the light source 20. During etching, the laser emitted by the light source 20 first passes through the second photomask 200, then through the first photomask 100, and finally projects onto the photoresist. Both the second photomask 200 and the first photomask 100 reduce the beam angle of the laser emitted by the light source 20, ensuring that the laser beam is a vertically downward beam.

[0037] Please refer to the following: Figure 3The first photomask 100 includes a first metal layer 110 and a first light-transmitting layer 120. The first metal layer 110 is attached to the bottom of the first light-transmitting layer 120 and has a plurality of first light-transmitting holes 130 thereon. The second photomask 200 includes a second metal layer 210 and a second light-transmitting layer 220. The second metal layer 210 is attached to the bottom of the second light-transmitting layer 220 and is attached to the top surface of the first light-transmitting layer 120. It has a plurality of second light-transmitting holes 230 thereon. The number of second light-transmitting holes 230 is the same as the number of first light-transmitting holes 130, and there is a one-to-one correspondence between the second light-transmitting holes 230 and the first light-transmitting holes 130.

[0038] The first light-transmitting layer 120 and the second light-transmitting layer 220 are generally made of transparent materials with high temperature resistance and hardness, such as glass or plexiglass, and are generally cuboid in shape. The first metal layer 110 and the second metal layer 210 are generally made of metal materials with high temperature resistance and hardness, such as nickel or chromium.

[0039] During etching, the laser emitted by the light source 20 first passes through the second transparent aperture 230 to form a transition beam propagating along the optical axis. The angle between the light rays in this transition beam and the optical axis does not exceed 2 degrees, meaning its beam angle is less than 4 degrees. After passing through the first transparent aperture 130, this transition beam forms the etching beam. The angle between the light rays in this etching beam and the optical axis does not exceed 0.6 degrees, meaning its beam angle is less than 1.2 degrees, much smaller than the beam angle of the transition beam. At this beam angle, the gap between the combined photomask 30 and the material to be etched 50 can be widened, solving the technical problem in the current proximity exposure machine where the optical path parallelism is not high, resulting in a relatively dispersed laser beam and requiring a lower gap. This saves photolithography preparation time and increases photolithography production capacity. It also reduces the risk of the photomask being scratched.

[0040] In some embodiments of this disclosure, the second light-transmitting aperture 230 can be aligned with the center of the first light-transmitting aperture 130 or aligned with the edge of the first light-transmitting aperture 130; this disclosure does not limit this. When the second light-transmitting aperture 230 is aligned with the center of the first light-transmitting aperture 130 and concentrically arranged, the line connecting the center of the first light-transmitting aperture 130 and the center of the second light-transmitting aperture 230 is the optical axis. This structure can ensure that the final etching laser beam angle is small, the beam parallelism is higher, and the change in beam cross-sectional area per unit length is smaller.

[0041] In some embodiments of this disclosure, the shapes of the first light-transmitting hole 130 and the second light-transmitting hole 230 are varied, including square holes, round holes, and oblong holes, specifically related to the pattern of the substrate to be etched. In particular, the diameter of the first light-transmitting hole 130 must not be larger than the diameter of the second light-transmitting hole 230. For example, when the diameter of the second light-transmitting hole 230 is 52 micrometers, the diameter of the first light-transmitting hole 130 is 50 micrometers to ensure a filtering effect. The light transmission effect is optimal when the diameter of the first light-transmitting hole 130 is equal to the diameter of the second light-transmitting hole 230.

[0042] Please refer to some embodiments of this disclosure. Figure 3 and Figure 4 An adhesive layer 300 is provided between the first photomask 100 and the second photomask 200, which bonds the first photomask 100 and the second photomask 200 together. The adhesive layer 300 needs to be made of a high-temperature resistant transparent adhesive material to ensure that the adhesiveness of the adhesive layer 300 will not disappear during the photolithography process.

[0043] In one embodiment of this application, the adhesive layer 300 includes a solid adhesive layer 310 and a liquid adhesive layer 320. The solid adhesive layer 310 is adhered to the side of the second metal layer 210 facing away from the second light-transmitting layer 220. The liquid adhesive layer 320 is applied to the side of the solid adhesive layer 310 facing away from the second metal layer 210 and is bonded to the first light-transmitting layer 120.

[0044] The aforementioned light-transmitting layer needs to be made using an overcoating (OC) adhesive, typically optically clear adhesive (OCA). Further, it includes silicone rubber, acrylic resin, and adhesives such as unsaturated polyester, polyurethane, and epoxy resin to ensure good optical performance and low curing shrinkage, thus ensuring precision during the photolithography process.

[0045] In some embodiments of this disclosure, the preparation process of the above-mentioned combined photomask 30 is as follows: first, the first photomask 100 and the second photomask 200 are cleaned; then, an optical adhesive is applied to the second metal layer 210 of the second photomask 200 to form the above-mentioned adhesive layer 300; then, the second photomask 200 is precisely placed on the first photomask 100 under the control of an electro-coupled device (CCD); finally, after curing, the above-mentioned combined photomask 30 is obtained.

[0046] Please refer to some embodiments of this disclosure. Figure 5The overall thickness of the aforementioned combined photomask 30 should be controlled at around 13 mm, with a maximum range between 12 mm and 14 mm, and generally needs to be controlled between 12.7 mm and 13.3 mm to match the proximity exposure machine, with an optimal thickness of 13 mm.

[0047] Meanwhile, the spacing between the first metal layer 110 and the second metal layer 210 should be controlled between 1 mm and 13 mm. The larger the spacing between the first metal layer 110 and the second metal layer 210, the lower the dispersion of the final emitted etching laser, the better the parallelism, and the closer it is to being straight.

[0048] For example, in one embodiment, the gap between the combined photomask 30 and the material to be etched 50 is 250 micrometers, then the formula is used to calculate...

[0049]

[0050] It can be seen that when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, ;when hour, .

[0051] In the formula above, The radial dimension of the cross-section through which the etching beam is projected onto the material 50 to be etched. The radial dimension of the first light-transmitting aperture 130 is... The gap between the combined photomask 30 and the material to be etched 50. This represents the maximum angle between the light rays in the etching laser beam and the optical axis. The distance between the first metal layer 110 and the second metal layer 210 is denoted as .

[0052] The calculation results from the above formula show that, In the case of, when hour, value relative to The increase in size is only 0.083 times the original size, which is small and meets the tolerance requirements. Therefore, in some embodiments of this application, two photomasks with a thickness of 6.5 mm can be stacked together to form a combined photomask 30. This combined photomask 30 can limit the expansion size of the etching laser to between 0.07 and 0.08 times the original size, which not only can effectively control the beam dispersion, but also increases the versatility of materials and reduces production costs due to the use of two identical photomasks.

[0053] Meanwhile, in one embodiment of this disclosure, the radial dimensions of both the first light-transmitting hole 130 and the second light-transmitting hole 230 are 50 micrometers, the thicknesses of both the first metal layer 110 and the second metal layer 210 are 0.8 micrometers, the thickness of the adhesive layer 300 is 1 micrometer, the thickness of the first transparent layer is 5 millimeters, and the thickness of the second transparent layer is 8 millimeters. The overall thickness of the photomask can be calculated to be 13.0018 millimeters, and the distance between the first metal layer 110 and the second metal layer 210 is 5.001 millimeters. Therefore, when the gap between the combined photomask 30 and the material to be etched 50 is 523.8 micrometers, the radial dimension of the cross-section of the etching beam projected onto the material to be etched 50 is 60.476 micrometers. If a single-layer photomask is used, the gap between the combined photomask 30 and the material to be etched 50 needs to be reduced to 50 micrometers. That is, this disclosure effectively controls the maximum angle between the light rays in the etching beam and the optical axis, making it less awkward than when using a single-layer photomask. (That is, the maximum angle between the light ray in the transition beam and the optical axis) becomes smaller. .

[0054] Therefore, in the embodiments of this disclosure, the expansion of the etching beam cross-section can be controlled even with a high gap, ensuring the fineness of the etching. This allows those skilled in the art to use coating methods and traditional photolithography processes to obtain finer patterns with lower processing steps even when the exposure machine is using a high gap. This solves the technical problem in the prior art where the optical path parallelism of current proximity exposure machines is not high, resulting in a more dispersed laser beam and requiring the use of a lower gap.

[0055] The above provides a detailed description of an exposure apparatus and its combined photomask 30 provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A combination reticle, characterized in that, The application relates to a combined mask, which comprises: a first mask comprising a first metal layer, wherein a plurality of first light-transmitting holes are formed in the first metal layer; a second mask comprising a second metal layer, wherein the second metal layer is arranged opposite to the first metal layer, a plurality of second light-transmitting holes are formed in the second metal layer, the second light-transmitting holes are arranged corresponding to the first light-transmitting holes along an optical axis, and the aperture of the first light-transmitting hole is not larger than the aperture of the second light-transmitting hole; wherein the second mask and the first mask can both reduce the beam angle of laser, and when etching, the laser first passes through the second mask and then passes through the first mask.

2. The combination reticle of claim 1, wherein, The first mask further comprises a first light-transmitting layer, and the first metal layer is attached to one side of the first light-transmitting layer; the second mask is attached to the side of the first light-transmitting layer away from the first metal layer, the second mask further comprises a second light-transmitting layer, and the second metal layer is attached to one side of the second light-transmitting layer and is attached to the first light-transmitting layer.

3. The combination reticle of claim 2, wherein, A glue layer is further arranged between the first mask and the second mask, and the glue layer bonds the first mask and the second mask.

4. The combination reticle of claim 3, wherein, The glue layer comprises: a solid glue layer attached to the side of the second metal layer away from the second light-transmitting layer; a liquid glue layer coated on the side of the solid glue layer away from the second metal layer.

5. The combination reticle of claim 2, wherein, The first light-transmitting hole and the second light-transmitting hole are concentrically arranged.

6. The combination reticle of claim 1, wherein, The overall thickness of the combined mask is greater than 12 mm and less than 14 mm.

7. The combination reticle of claim 6, wherein, The distance between the first metal layer and the second metal layer is between 1 mm and 13 mm.

8. An exposure apparatus characterized by comprising: The application further relates to a mask etching device, which comprises: the combined mask according to any one of claims 1 to 7; a bearing platform arranged on the side of the first metal layer away from the second metal layer, wherein the bearing platform is used for bearing a material to be etched; a light source arranged on the side of the combined mask away from the bearing platform, wherein the laser emitted by the light source passes through the first light-transmitting hole and the second light-transmitting hole to form an etching beam, so as to etch the material to be etched, and the angle between the light rays in the etching beam and the optical axis is less than 0.5 degrees.

9. The exposure apparatus according to claim 8, wherein The laser emitted by the light source passes through the second light-transmitting hole to form a transition beam along the direction of the optical axis, and the transition beam passes through the first light-transmitting hole to form an etching beam; the beam angle of the transition beam is greater than the beam angle of the etching beam.

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