Substrate adsorption device

Abstract

The invention discloses a substrate adsorption device, belongs to the technical field of substrate adsorption, and is used for solving the problem of substrate release delay of a suction cup with a sealing element. The substrate adsorption device comprises a suction cup body, an adsorption space, a sealing piece and a communication structure, when a substrate is adsorbed, the sealing piece, the substrate and the suction cup body define a sealed space, and the communication structure communicates the sealed space with the adsorption space. By arranging the communication structure, the two spaces which are originally isolated from each other are communicated and unified into one gas space, so that when the substrate is released, the negative pressure can be synchronously and quickly relieved. Release delay caused by pressure difference is fundamentally eliminated, instant and complete release of the substrate is achieved, and production efficiency and equipment reliability are improved.

Description

Technical Field

[0001] This invention application relates to the field of substrate adsorption technology, and in particular to a substrate adsorption device. Background Technology

[0002] In precision manufacturing fields such as semiconductors and flat panel displays, substrate adsorption devices are indispensable key equipment in the processing flow. They use vacuum adsorption to firmly fix thin-film substrates such as wafers and photomasks onto a support stage, ensuring the stability of the substrate position during high-precision processes such as etching, coating, and developing.

[0003] Traditional substrate adsorption devices typically incorporate multiple adsorption holes or air grooves on their support platform, forming an adsorption space. When connected to a negative pressure source, a negative pressure is generated within this space, adsorbing the substrate onto the support platform. However, as substrate size increases and thickness decreases, substrate warping becomes increasingly prominent. To effectively adsorb such warped substrates, existing technologies commonly employ a sealing element made of a flexible material (such as rubber) around the periphery of the suction cup. The design intent is to utilize the height advantage of the sealing element, allowing it to make earlier contact with the edge of the warped substrate, thereby more quickly forming an initial sealed environment and improving the adsorption success rate.

[0004] However, the inventors discovered that this improved solution to address the adsorption warpage problem introduced a new, more subtle, and less noticeable technical issue: a significant release delay lasting several seconds or even tens of seconds during substrate release. The problem's insidious nature lies in its root cause: it doesn't originate from the active design of the suction cup, but rather from a structure that arises from the addition of a seal. Specifically, due to the need for seal installation and deformation, an independent, annular sealed space is unintentionally formed between the seal, substrate, and the outer edge of the suction cup itself upon completion of adsorption. In industry practice, this space is usually considered part of the seal's structure, and its independent side effects in the vacuum system are generally overlooked. Therefore, when release delay occurs, technicians often attribute it to other factors such as residual pressure in the tubing, electrostatic adsorption on the substrate surface, or material adhesion, failing to accurately identify this physically isolated sealed space as the true culprit. This sealed space also creates negative pressure during adsorption, but after the release command is issued, because it is not connected to the main adsorption space, the negative pressure inside cannot be released synchronously, leading to delayed wafer release. This incomplete release not only disrupts the continuity of the process and reduces production efficiency, but also brings serious technical risks. If subsequent robotic gripping operations are performed before the substrate is completely detached, it can easily lead to a decrease in substrate positioning accuracy, unstable clamping, or even displacement or drop during handling, causing damage or contamination to high-value substrates.

[0005] More importantly, the path to solving this technical problem is blocked by a deeply ingrained industry bias. In traditional suction cup designs without external seals, the absolute airtightness of the adsorption space is a prerequisite for achieving adsorption functionality. Any groove or hole on the outer edge of the suction cup that connects to the adsorption space is considered a failed design. When technicians add seals to traditional suction cups, they subconsciously transfer the design principle that the adsorption area must not leak to the edge to the new structure due to inertia. This mindset means that even if technicians are aware of the existence of an isolated sealed space, they completely rule out the possibility of balancing internal and external pressures by actively creating a connecting structure at the edge of the suction cup.

[0006] Therefore, accurately identifying the root cause of release delay caused by the auxiliary structure and further overcoming industry technical biases to provide a substrate adsorption device that can achieve rapid and delay-free release has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] The technical problem this invention aims to solve is that existing substrate adsorption devices with sealing elements suffer from excessively long release times during substrate release because the pressure in the sealed space formed by the sealing element and the main adsorption space cannot be released synchronously, affecting production efficiency and process reliability. Therefore, this invention provides a substrate adsorption device to solve the technical problems mentioned in the background art, achieving rapid and delay-free release of the substrate.

[0008] To achieve the above objectives, the present invention provides a substrate adsorption device, comprising: a suction cup body having a support platform for supporting a substrate; at least one adsorption space disposed on the support platform, the adsorption space being configured to communicate with a negative pressure source to generate adsorption force; at least one sealing member disposed on the suction cup body; when the substrate is adsorbed, the sealing member, the substrate, and the suction cup body together form a sealed space; and at least one communicating structure connecting the adsorption space and the sealed space.

[0009] By setting up a connecting structure, the originally isolated adsorption space and sealed space are connected into a unified pressure system. In this way, during adsorption, the two spaces can be evacuated simultaneously; during release, the negative pressure in the two spaces can be released simultaneously and quickly, thereby fundamentally eliminating the release delay problem caused by pressure difference, realizing instantaneous and complete release of the substrate, and significantly improving production efficiency and equipment reliability.

[0010] According to another embodiment of the present invention, the communication structure is one or more communication slots formed on the support platform; and / or, the communication structure is one or more communication channels disposed inside the suction cup body. By employing communication slots or internal communication channels to achieve the communication structure, the structure is simple, easy to manufacture, and inexpensive, and is extremely reliable in operation, requiring no additional moving parts or complex control systems.

[0011] According to another embodiment of the present invention, when the connecting structure is the connecting groove, the connecting groove extends radially from the adsorption space to the sealing space; and / or, when the connecting structure is the connecting channel, the connecting channel extends radially from the adsorption space to the sealing space. By making the connecting structure extend radially, the shortest and most direct path is provided for the gas flow between the adsorption space and the sealing space, thereby maximizing the speed and efficiency of pressure synchronization and further ensuring the rapid release performance of the substrate.

[0012] According to another embodiment of the present invention, the sealing element is disposed around the outer periphery of the suction cup body.

[0013] According to another embodiment of the present invention, the support platform is divided into multiple adsorption regions by at least one sealing member, the sealing member being disposed between adjacent adsorption regions, and the at least one adsorption space being disposed within the adsorption regions. By dividing the support platform into multiple adsorption regions, the device can better adapt to the adsorption requirements of large-size or irregularly shaped substrates, and provides a structural basis for realizing independent zoned control of the substrate.

[0014] According to another embodiment of the present invention, the connecting structure is used to connect the adsorption space in the adsorption region with the sealed space corresponding to the same adsorption region. By ensuring that the connection only occurs within the same adsorption region, pressure crosstalk between different adsorption regions is effectively avoided. This solution ensures that releasing a specific region does not affect the adsorption state of other regions, thereby achieving high-precision, independent, and rapid zoned release control, meeting the requirements of advanced process flows.

[0015] According to another embodiment of the present invention, one or more air grooves formed on the support platform are used to constitute the at least one adsorption space.

[0016] According to another embodiment of the present invention, the support platform includes a plurality of platforms, and the adsorption space is formed between adjacent platforms.

[0017] According to another embodiment of the present invention, the plurality of stages include at least one outer stage and a plurality of inner stages; along the height direction of the stages, the top surface height of the outer stage is lower than the top surface height of the inner stage. By setting the height difference between the stages, the portion of the outer stage lower than the inner stage serves as a connecting structure, allowing the inner stage, which is higher in the center region of the suction cup, to first contact and stabilize the substrate, and then the negative pressure pulls down the warped edge portion. This solution significantly improves the success rate and reliability of adsorption of warped substrates and reduces the stress applied to the substrate during adsorption.

[0018] According to another embodiment of the present invention, the seal is made of a flexible material, including rubber or silicone, or the substrate is a semiconductor wafer, a photomask, or a flat panel display substrate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a first embodiment of the substrate adsorption device of the present invention; Figure 2 These are cross-sectional schematic diagrams of Embodiment 1 of the substrate adsorption device of the present invention under different states; Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the substrate adsorption device of the present invention; Figure 4 This is a schematic diagram of the structure of another substrate adsorption device of the present invention; Figure 5 This is a cross-sectional schematic diagram of Embodiment 3 of the substrate adsorption device of the present invention; In the picture: 10: Substrate adsorption device; 100: Suction cup body; 101: Support stage; 102: Air groove; 200: Seal; 300: Connecting groove; 301: Connecting channel; SS: Adsorption space; CS: Sealing space; 400: Adsorption area; 500: Support stage; 501: Outer support stage; 502: Inner support stage. Detailed Implementation

[0020] It should be noted that the embodiments described below are merely several preferred embodiments of the present invention, intended to illustrate the technical solutions of the present invention in more detail, and not to limit its scope of protection. Those skilled in the art should understand that different technical features of the present invention can be replaced or combined in various ways. For example, the peripheral sealing scheme in Embodiment 1 can also use the internal connecting channel in Embodiment 2 as the connecting structure; conversely, the internal partitioning scheme in Embodiment 2 can also use the surface connecting groove in Embodiment 1 as the connecting structure. Therefore, any combination, modification, or equivalent substitution made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. Example

[0021] To better understand the present invention, a preferred embodiment is described below with reference to the accompanying drawings. This embodiment provides a substrate adsorption device 10, which is particularly suitable for the efficient adsorption and rapid release of large-size, warp-prone wafers in semiconductor manufacturing. (Refer to...) Figure 1 and Figure 2 The substrate adsorption device 10 includes a circular suction cup body 100, which can be made of materials such as aluminum alloy with good thermal conductivity or ceramic with high wear resistance. The suction cup body 100 has a support platform 101 for stably supporting the substrate. Multiple concentric annular air grooves 102 are formed on the support platform 101, which together constitute at least one adsorption space SS as described in this invention. A negative pressure pipeline (not shown) is provided inside the suction cup body 100, which connects all the air grooves 102 to an external negative pressure source such as a vacuum pump, so as to create negative pressure by evacuating air during adsorption.

[0022] In this embodiment, an annular seal 200 made of flexible materials such as silicone rubber is fixed to the outer periphery of the suction cup body 100 by means of heat melting or mechanical snap-fit.

[0023] It should be noted that the initial purpose of adding the sealing element 200 in the existing technology was to address the warping problem of large-size wafers. The design concept utilizes the height advantage of the sealing element 200, which is higher than the support stage 101 in its free state, allowing it to contact the edge of the warped wafer earlier, thereby forming an initial sealed environment more quickly and effectively adsorbing the warped wafer. Furthermore, due to the installation and deformation requirements of the sealing element 200, its root is usually lower than the support stage 101. This unintentionally and incidentally creates an annular sealing space CS between the sealing element 200, the wafer, and the outer edge of the suction cup body 100 upon completion of adsorption.

[0024] However, this improved design, introduced to solve the adsorption problem, inadvertently caused a completely new and more hidden technical problem: a severe delay of several seconds or even tens of seconds occurred during wafer release. Prior to this invention, it cannot be ruled out that others had observed similar phenomena, but there was no evidence to suggest that the delay in wafer release was caused by the unintentionally created sealing space CS.

[0025] Tracing the root cause of the delayed release phenomenon is the first step in making a creative contribution to this invention. Through in-depth research and experimentation based on the observed phenomenon, the inventors discovered that the crux of the problem lies in the sealed space CS formed by the added sealing element 200. This sealed space CS and the adsorption space SS, which is composed of the air groove 102, are structurally independent and physically isolated from each other. This results in the negative pressure in the adsorption space SS being quickly released during wafer release, but the sealed space CS, being enclosed and lacking a venting channel, experiences a slow leakage of internal negative pressure, causing the wafer edge to adhere to the suction cup.

[0026] More importantly, the second step in this invention's inventive contribution lies in breaking down industry-wide technical biases that hinder the solution to this problem. Based on the technical concept of adding a sealing element, its improvement rests on the traditional suction cup. In traditional solutions, the absolute airtightness of the adsorption gas groove is essential for achieving the adsorption function. The applicant discovered that non-absolute airtightness leads to the absence of a true adsorption space, rendering the designed suction cup prototype unusable. Therefore, any attempt to create a groove or hole connecting the suction cup to the gas groove on its outer edge is considered a design failure. Consequently, when researchers add a sealing element 200 to a traditional suction cup, they subconsciously assume, due to ingrained thinking, that this adsorption area must not leak to the edge. The design principle of not allowing grooves on the outer edge is transferred to the new structure, completely blocking the motivation and possibility of seeking a connection path at the suction cup edge to balance pressure. Those skilled in the art, when faced with the release problem we discovered, will find their design thinking strongly constrained by the traditional suction cup concept.

[0027] However, the applicant of this invention has broken through this conventional thinking. The applicant realized that with the introduction of the seal 200, the airtight boundary of the entire system has fundamentally shifted—from the suction cup support platform 101 to the seal 200 itself. Based on this groundbreaking understanding, this invention boldly creates multiple evenly distributed connecting grooves 300 on the support platform 101 of the suction cup body 100 to connect the adsorption space SS and the sealing space CS. Specifically, these connecting grooves 300 start from the outermost gas groove 102 and extend radially outward to the area where the sealing space CS is located. In the system of this invention, these connecting grooves 300 become channels connecting the balanced air pressure of the two internal negative pressure regions, completely breaking the inherent constraints of traditional design. Through this extremely simple yet ingeniously conceived connecting structure, the adsorption space SS and the sealing space CS are connected and unified into a single gas space. This not only fundamentally solves the problem of the inability to release pressure synchronously in two spaces, achieving instantaneous and complete release of the substrate and significantly reducing the release time from tens of seconds to less than one second, but it is also achieved without adding any complex valves or independent control systems, greatly improving the reliability of the equipment and reducing costs. The significant performance improvement brought about by this simple structure is something that those skilled in the art would hardly have anticipated under the aforementioned technical biases. Example

[0028] This invention is not limited to the peripheral sealing structure described in Embodiment 1 above. Its core technical concept is also applicable to solving more complex application scenarios involving the independent adsorption and release of large-size substrates in different regions.

[0029] This embodiment provides a substrate adsorption device 10 for adsorbing large-size flat panel display glass substrates or photolithographic masks. (Refer to...) Figure 3 The suction cup body 100 of the device is rectangular to accommodate a substrate that is usually rectangular. The support platform 101 is divided into multiple independent rectangular adsorption areas 400 that can be independently pressure controlled by multiple strip seals 200 arranged in a grid.

[0030] Within each adsorption region 400, air grooves 102 arranged in a serpentine pattern are provided, forming an adsorption space SS for that region. Each adsorption space SS of each adsorption region 400 is connected to an external multi-channel pressure controller via an independent internal pipeline. Similar to the principle of Embodiment 1, a corresponding linear sealing space CS is also incidentally formed between the root of each seal 200 and the substrate.

[0031] Similarly, if these sealed spaces (CS) are not treated, the same technical problem of release delay as in Example 1 will be encountered when rapid release of the entire substrate or a specific area is required. The technical bias that the adsorption area must not leak to the edge, when applied to this partitioned structure, will also limit those skilled in the art from finding effective solutions to the release delay of the wafer.

[0032] This embodiment cleverly extends and applies the groundbreaking core concept from Embodiment 1. Specifically, multiple tiny connecting structures are provided within each adsorption region 400, such as connecting channels 301 located inside the suction cup body 100. These connecting channels 301 are only used to connect the adsorption space SS within the adsorption region 400 to the corresponding sealed space CS, and do not connect to adjacent adsorption regions 400.

[0033] With this design, when a specific area needs to be released, the negative pressure in that area can be simultaneously and rapidly released only within its adsorption space SS and sealing space CS, without causing any pressure interference to other areas still in the adsorption state. This localized pressure synchronization release scheme not only solves the release delay problem in partitioned adsorption scenarios, but also, based on Embodiment 1, further achieves high-precision, regionalized, and rapid independent control of adsorption and release for large-size substrates. This is particularly important for advanced processes requiring localized processing or inspection. In such a design, the substrate adsorption device 10 is not required to be rectangular; a circular shape is acceptable, for example... Figure 4 Another substrate adsorption device 10 is typically designed with an annular partitioned adsorption scheme, and the seal 200 is also designed in an annular shape to isolate different annular adsorption areas. Example

[0034] This invention provides a further improvement to optimize substrate adsorption performance, particularly for substrates with severe warping. This embodiment provides a substrate adsorption device 10, which is structurally optimized based on Embodiment 1. (Refer to...) Figure 5 The suction cup body 100 of the device has a support platform 101 composed of multiple independent concentric ring platforms 500. Annular grooves (i.e., air grooves) are naturally formed between adjacent platforms 500, and these air grooves 102 constitute the adsorption space SS for vacuuming.

[0035] The key technical feature of this embodiment lies in the carefully differentiated design of the heights of these support platforms 500. Specifically, the plurality of support platforms 500 includes at least one outer support platform 501 and a plurality of inner support platforms 502. Along the height direction of the support platform 101, the top surface height of the outer support platform 501 is intentionally designed to be lower than the top surface height of all the inner support platforms 502. Preferably, the top surface height of all the inner support platforms 502 can be kept equal, forming a flat central adsorption reference surface. When adsorbing a substrate with a central depression or warped edges, this height difference design means that the inner support platforms 502 with higher elevation of the suction cup body 100 will first contact and stabilize the central region of the substrate. Subsequently, as the adsorption space SS begins to be evacuated, the resulting negative pressure will gently and controllably pull the warped edge portion of the substrate downward until it is tightly fitted with the lower-elevation outer support platform 501 and the outer sealing member 200. This process effectively avoids adsorption failure caused by warping or substrate damage caused by excessive adsorption stress, greatly improving the reliability and adaptability of adsorption on various warped substrates.

[0036] Of course, the substrate adsorption device 10 of this embodiment is also provided with a connecting groove 300 as described in Embodiment 1 or a connecting channel 301 as described in Embodiment 2, to connect the adsorption space SS formed between the outermost stage 500 and the second outermost stage with the sealed space CS enclosed by the sealing member 200, or the portion of the outer stage 501 lower than the inner stage 502, which can serve as the connecting structure of the present invention. Through this design, the substrate adsorption device 10 of this embodiment integrates the two functions of optimizing the adsorption of warped substrates and achieving rapid, delay-free release.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, various modifications, equivalent substitutions, or improvements can be made within the core ideas and principles of the present invention, such as changing the shape, number, and distribution of the connecting grooves, or using seals of different materials and structures. All such variations should be included within the scope of protection of the present invention.

[0038] Furthermore, the terms used in this specification, such as "suction cup body," "seal," and "connection structure," are generic names used for ease of description. Any technical feature with the same structure, positional relationship, or ability to achieve the same function should be considered to fall within the protection scope of this invention.

Claims

1. A substrate adsorption device, characterized in that, include: The suction cup body (100) has a support stage (101) for carrying the substrate; At least one adsorption space (SS) is provided on the support platform (101), the adsorption space (SS) being used to communicate with a negative pressure source to generate adsorption force; At least one seal (200) is disposed on the suction cup body (100); When the substrate is adsorbed, the sealing member (200), the substrate and the suction cup body (100) together form a sealed space (CS); At least one connecting structure that connects the adsorption space (SS) to the sealed space (CS).

2. The substrate adsorption device according to claim 1, characterized in that, The connecting structure is one or more connecting slots (300) opened on the support platform (101); and / or, the connecting structure is one or more connecting channels (301) disposed inside the suction cup body (100).

3. The substrate adsorption device according to claim 2, characterized in that, When the connecting structure is the connecting groove (300), the connecting groove extends radially from the adsorption space (SS) to the sealing space (CS); and / or, when the connecting structure is the connecting channel (301), the connecting channel extends radially from the adsorption space (SS) to the sealing space (CS).

4. The substrate adsorption device according to claim 1, characterized in that, The sealing element (200) is disposed around the outer periphery of the suction cup body (100).

5. The substrate adsorption device according to claim 1, characterized in that, The support platform (101) is divided into a plurality of adsorption areas (400) by at least one of the sealing elements (200), the sealing elements (200) being disposed between adjacent adsorption areas (400), and at least one of the adsorption spaces (SS) being disposed within the adsorption areas (400).

6. The substrate adsorption device according to claim 5, characterized in that, The connecting structure is used to connect the adsorption space (SS) in the adsorption region (400) with the sealing space (CS) corresponding to the same adsorption region (400).

7. The substrate adsorption device according to claim 1, characterized in that, One or more air grooves (102) formed on the support platform (101) are used to form the at least one adsorption space (SS).

8. The substrate adsorption device according to claim 1, characterized in that, The support stage (101) includes a plurality of stages (500), and the adsorption space (SS) is formed between adjacent stages (500).

9. The substrate adsorption device according to claim 8, characterized in that, The plurality of said platforms (500) include at least one outer platform (501) and a plurality of inner platforms (502); along the height direction of the platform (101), the top surface height of the outer platform (501) is lower than the top surface height of the inner platform (502).

10. The substrate adsorption device according to claim 1, characterized in that, The seal (200) is made of a flexible material, including rubber or silicone. Alternatively, the substrate may be a semiconductor wafer, a photomask, or a flat panel display substrate.

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