A wafer pulling structure

Abstract

This invention discloses a wafer pulling structure, including at least one pulling arm, an arc-shaped notch formed by the pulling arm, and an open end. The inner diameter of the arc-shaped notch is adapted to the outer diameter of the wafer, and the width of the open end is smaller than the outer diameter of the wafer. It also includes a through channel extending along the central axis of the arc-shaped notch, and a wafer positioning detection unit. The wafer positioning detection unit is movably disposed in the through channel and at least partially extends through the pulling arm into the arc-shaped notch along a second direction to abut against the wafer. The through channel has a limiting conduit, and a portion of the wafer positioning detection unit is located within this limiting conduit to form a limiting fit between the two in a first direction. The first and second directions are perpendicular or tend to be perpendicular. The wafer positioning detection unit is movably disposed in the through channel, enabling it to not only detect the presence or absence of the wafer but also, in conjunction with the pulling arm, securely clamp the wafer, achieving a two-in-one function of secure wafer clamping and wafer detection.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor integrated circuit wafer manufacturing technology, and in particular relates to a wafer pulling structure. Prior Technology

[0002] In the semiconductor integrated circuit wafer manufacturing process, wafers need to undergo multiple cleaning processes to remove surface contaminants. For example, in the cleaning unit of a Chemical Mechanical Planarization (CMP) machine, multiple cleaning processes are required during operation, and these processes are completed between different modules. Therefore, a wafer transfer hand is needed to move the wafer between the various modules and ensure stable and efficient wafer handling.

[0003] Currently, the presence or absence of a wafer is typically determined by detecting obstructions to the optical path during the wafer's horizontal movement. This method is generally suitable for applications with a single lifting handle. However, in applications with multiple lifting handles, the shared optical path leads to insufficient detection accuracy and the inability to achieve real-time detection. Furthermore, when used in cleaning processes, optical detection is susceptible to humid environments and the presence of droplets on the detection device, resulting in a very high probability of false detections. For example, a Chinese invention patent (patent number CN119361497A) entitled "Wafer Clamping Arm" improves upon this by using a fixed design for the sensor holder (both the receiving and transmitting end holders are large hydrophobic angle structures). The sensor is clamped and photoelectric through the fixed holder, fixing the sensor holder to the clamping arm. The hydrophobic structure reduces water droplet interference, but false detections are still unavoidable.

[0004] Of course, detection methods are not limited to optical sensors. For example, a Chinese invention patent (patent number CN222021614U) entitled "A Wafer Transfer Robot and Cleaning Device" mentions the use of frequency sensors, tension sensors, and weighing sensors. However, it is not difficult to see that the traditional sensor placement is fixed. However, fixed placement presents several problems: ① Different process environments (such as changes in liquid level in wet processes) require the sensor to flexibly adjust its position to avoid interference (such as droplet splashing). Fixed designs struggle to dynamically adapt to environmental changes, potentially reducing detection reliability. ② Furthermore, fixed sensors cannot adjust the detection angle and distance according to changes in wafer size or position, potentially leading to blind spots. For example, when the wafer position shifts during the pull-up process, a fixed sensor may not cover the entire area. ③ In addition, the dynamic oscillation of the wafer during pull-up can cause intermittent sensor signals. If the sensor is movable, it can track the wafer position in real time to optimize the detection path, a function that a fixed design cannot achieve.

[0005] Furthermore, traditional cleaning equipment typically uses wafer transfer arms with arc-shaped notches to transfer wafers between cleaning or drying units. However, these notched wafer transfer arms are prone to misalignment or wobbling when holding wafers, causing wafer displacement during transfer and affecting subsequent cleaning results. To address this issue, existing technologies propose using special clamping mechanisms that enhance wafer fixation by adjusting the clamping force. However, this increases system complexity, reduces the stability of the robotic arm structure, and increases the possibility of contamination due to excessive wafer contact area, failing to fundamentally solve the wafer misalignment problem. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a wafer lifting structure, which can stably clamp the wafer by using the cooperation of the wafer limiting detection unit and the lifting arm, and can also detect in real time whether the wafer is stably clamped.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a wafer pulling structure, including at least one pulling arm, an arc-shaped notch formed by the pulling arm, and an open end, wherein the inner diameter of the arc-shaped notch is adapted to the outer diameter of the wafer, and the width of the open end is smaller than the outer diameter of the wafer, and further including a through channel extending along the central axis of the arc-shaped notch, and a wafer positioning detection unit, wherein the wafer positioning detection unit is movably disposed in the through channel, and at least part of it can pass through the pulling arm along a second direction and extend into the arc-shaped notch to abut against the wafer, wherein the through channel has a positioning conduit, and part of the wafer positioning detection unit is located in the positioning conduit to form a positioning fit between the two in a first direction, wherein the first direction and the second direction are perpendicular or tend to be perpendicular.

[0008] Furthermore, the wafer positioning detection unit includes a flat pole movably disposed in the through channel and a sensor connected to the flat pole. The flat pole can pass through the lifting arm and extend into the arc-shaped notch to abut against the wafer. The sensor is used to sense whether the lifting arm is holding the wafer.

[0009] Furthermore, the sensing element is located at the end of the spreading member and is used to sense whether the spreading member is in contact with the wafer.

[0010] Furthermore, the sensing element is located on the side of the carrying pole and is used to sense the distance of relative movement of the carrying pole relative to the lifting arm. The through channel has an enlarged diameter area for accommodating the sensing element.

[0011] Furthermore, the end of the carrying pole is connected to a contact end with a receiving groove, the opposite side walls of which are flared conical.

[0012] Furthermore, the lifting arms have a second mounting groove for accommodating the contact end.

[0013] Furthermore, the moving path of the spreading member coincides with or tends to coincide with the center line of the arc-shaped notch; the limiting channel and part of the wafer limiting detection unit form a third-dimensional limiting fit, so that the spreading member is located in the plane of the arc-shaped notch.

[0014] Furthermore, the carrying pole has at least a first stroke and a second stroke. When the carrying pole travels in the first stroke, it abuts against the outer wall of the wafer to cooperate with the lifting arm to clamp the wafer. The second stroke is greater than the first stroke.

[0015] Furthermore, it also includes a base to which the lifting arm is connected; the base is connected to a limiting member, and the carrying pole is movably connected to the limiting member in a concentric and coaxial manner.

[0016] Furthermore, the lifting arm has a first mounting groove, and the limiting member is located within the first mounting groove.

[0017] Furthermore, the spreading pole and the limiting member are parts of the cylinder.

[0018] The beneficial effects of this invention are: 1) The wafer positioning detection unit is movably installed in the through-channel, enabling it to not only detect the presence or absence of the wafer but also to work with the lifting arm to securely clamp the wafer, achieving a two-in-one function of secure wafer clamping and wafer detection; 2) The through-channel design allows the wafer positioning detection unit to be movably installed within it, without occupying additional space in the wafer lifting structure or requiring significant modifications to the existing structure. It also reduces the exposure of the wafer positioning detection unit to the environment, lowering the risk of interference with surrounding equipment; 3) The through-channel is designed with a limiting channel, effectively preventing the wafer positioning detection unit from shifting laterally or in multiple directions; 4) The cooperation of the flat arm and the sensing element not only clamps the wafer to prevent vibration but also instantly detects its presence or absence, determining whether the wafer is securely clamped by the lifting structure. 5) The flat arm and the open end work together to achieve a three-point stable clamping of the wafer. After the wafer is clamped, it can be used for vertical lifting and can also be moved in various angles and directions such as horizontal flipping, making the wafer clamping more flexible; 6) The flat arm and the wafer clamping effectively prevent the wafer from falling off and reduce the risk of wafer damage during transmission; 7) The sensor can be set in various positions, and multiple positions can be set to detect the presence or absence of the wafer, increasing the timeliness of detection; 8) The through channel and the wafer limit detection unit are located in the center of the lifting arm to avoid vibration or fatigue fracture of the lifting arm caused by eccentric load. The through channel is easy to integrate protective structures such as waterproof coatings to prevent chemical liquids from seeping in and improve reliability in humid environments; 9) The upper end of the flat arm carries a connector and the lower end carries a contact end, so that the flat arm acts as a flat arm that carries the load at both ends and limits the middle. Furthermore, the sensing element is located on the side of the spreading member, which is convenient for debugging; 10) The contact end is set to securely clamp the wafer while preventing the front of the wafer from being scratched. At the same time, the contact end has a widened conical receiving groove, which facilitates the introduction of the wafer, that is, facilitates the clamping of the wafer; 11) The limiting member and the spreading member can be a cylinder structure, which is convenient for material selection and reduces processing costs. Simple Explanation of the Diagram

[0019] Figure 1 is a front view of the present invention, in which the wafer is held in the clamp.

[0020] Figure 2 is a cross-sectional view of the present invention, in which the wafer is held in the clamp.

[0021] Figure 3 is a perspective view of the present invention, in which the wafer is held in a clamp.

[0022] Figure 4 is a two-dimensional view of the present invention, in which the wafer is held in the clamp.

[0023] Figure 5 is a perspective view of the present invention.

[0024] Figure 6 is a perspective view of the present invention.

[0025] Figure 7 is an enlarged view of the structure at point A in Figure 6. Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] A wafer pulling structure includes at least one pulling arm 1, an arc-shaped notch 2 formed by the pulling arm 1, and an open end 3. The inner diameter of the arc-shaped notch 2 is adapted to the outer diameter of the wafer 4 to be clamped, meaning that the wafer 4 can pass through the arc-shaped notch 2. The width of the open end 3 is smaller than the outer diameter of the wafer 4, so that when the wafer 4 enters the plane of the arc-shaped notch 2, the wafer pulling structure moves upward or downward, so that the center of the wafer 4 is located below the center of the arc-shaped notch 2, and the wafer 4 is hung on the open end 3. At this time, the wafer pulling structure can move synchronously with the wafer 4.

[0028] As shown in Figure 2, the wafer pulling structure also includes a through channel 8 extending along the central axis of the arc-shaped notch 2, and a wafer positioning detection unit 9. The wafer positioning detection unit 9 is movably disposed in the through channel 8, and at least a portion of the wafer positioning detection unit 9 can extend into the arc-shaped notch 2 through the pulling arm 1 along a second direction, thereby abutting against the wafer 4. Here, the second direction is parallel to the direction of the central axis of the arc-shaped notch 2.

[0029] The through channel 8 has a limiting conduit 81, and a portion of the wafer limiting detection unit 9 is located within this limiting conduit 81, thus forming a limiting fit between the wafer limiting detection unit 9 and the limiting conduit 81. Specifically, this is a limiting fit in a first direction, which is perpendicular to or nearly perpendicular to the second direction. In other words, when the limiting conduit 81 is a hollow conduit, its inner diameter is equal to the outer diameter of the portion of the wafer limiting detection unit 9, thus preventing the wafer limiting detection unit 9 from arbitrarily swaying laterally. The limiting conduit 81 and the portion of the wafer limiting detection unit 9 form a limiting fit in a third direction, which is perpendicular to both the first and second directions, i.e., the direction perpendicular to the plane of the paper in Figure 2. This ensures that the flat member 5 is located in the plane of the arc-shaped notch 2, and the wafer limiting detection unit 9 does not shift in the direction perpendicular to the paper.

[0030] The interior of the through channel 8 can be coated with a waterproof coating to prevent chemical liquids from seeping into the through channel 8, thereby preventing the spreader 5 from moving up and down in the through channel 8 with liquid in a humid environment, and improving the stability of operation in a humid environment.

[0031] As shown in Figures 1-6, in this embodiment, there is only one lifting arm 1, which is a rigid, integral structure. The wafer positioning detection unit 9 includes a flat pole 5 that is movably disposed within the through channel 8 and can move relative to the lifting arm 1, and a sensor 6 connected to the flat pole 5. The flat pole 5 can pass through the lifting arm 1 and extend into the arc-shaped notch 2 to abut against the wafer 4, while the sensor 6 is used to sense whether the lifting arm 1 is holding the wafer 4.

[0032] Specifically, the movement path of the support member 5 coincides with or nearly coincides with the center line of the arc-shaped notch 2. In other words, as shown in Figure 1, the center line of the arc-shaped notch 2 is L, which passes through the center of the clamped wafer 4. The center line of the support member 5 also coincides with this L line. Taking the direction shown in Figure 1 as an example, the support member 5 moves up and down along the L line.

[0033] The sensor 6 can be positioned in multiple locations. For example, the sensor 6 can be positioned at the end of the spreader 5 to sense whether the spreader 5 is in contact with the wafer 4. As shown in Figures 6 and 7, the sensor 6 is positioned at the lower end of the spreader 5 (the sensor 6 is marked in the figure as an approximate position). When the lower end of the spreader 5 is in contact with the sidewall of the wafer 4, the sensor 6 senses that the spreader 5 is in contact with the wafer 4 and receives a signal that the spreader 5 is holding the wafer 4.

[0034] As shown in Figures 1-3, the sensor 6 can also be disposed on the side of the spreader 5 to sense the distance of relative movement of the spreader 5 relative to the lifting arm 1. The through channel 8 has an enlarged diameter area 82 for accommodating the sensor 6. In other words, the lateral width of the enlarged diameter area 82 is greater than the inner diameter of the limiting pipe 81, thereby preventing the wafer limiting detection unit 9 from lateral displacement while providing space for the installation of the sensor 6. Of course, the specific position of the sensor 6 on the side of the spreader 5 is optional and not limited. Specifically, the spreader 5 has at least a first stroke and a second stroke. When the spreader 5 travels the first stroke, it abuts against the outer wall of the wafer 4, thereby cooperating with the lifting arm 1 to clamp the wafer 4, achieving three-point clamping of the wafer 4, making the clamping more stable. The aforementioned first stroke is the distance between the arc-shaped notch 2 and the outer wall of the wafer 4 when the wafer 4 is hung on the opening end 3.

[0035] When the carrying pole 5 travels its second stroke, since this second stroke is longer than the first stroke, the sensor 6 detects the difference between the second and first strokes. This indicates that the wafer 4 is not currently attached to the open end 3, and the sensor 6 receives a signal that the carrying pole 5 is not holding the wafer 4. Of course, the first stroke, more precisely, refers to the distance between the end of the carrying pole 5 and the outer wall of the wafer 4 when the wafer 4 is attached to the open end 3. There is no specific limitation on the first stroke; it is only used to illustrate that during the first stroke, the carrying pole 5 is against the wafer 4, and during the second stroke, since the carrying pole 5 is not obstructed by the wafer 4, it can continue to move a greater distance relative to the first stroke.

[0036] Of course, it is also possible to set the sensor 6 at both the end of the carrying pole 5 and the side of the carrying pole 5; there are no specific restrictions.

[0037] To ensure a stable clamping of the wafer 4 to the support member 5, a contact end 51 is connected to the end of the support member 5, as shown in Figure 7. The contact end 51 has a receiving groove 52, the opposite side walls of which are flared conical. The side wall of the wafer 4 can abut against the top surface of the receiving groove 52, but the surface of the wafer 4 will not contact the side wall of the receiving groove 52, ensuring that the surface of the wafer 4 is not damaged. A sensor 6 can be provided on the contact end 51. Of course, the receiving groove 52 can also be provided with only one outwardly inclined side wall to prevent the contact end 51 from contacting the front of the wafer 4. The inclined side wall of the receiving groove 52 ensures that the wafer 4 is smoothly guided through the beveled edge during the clamping process, ensuring the stability of the wafer 4 clamping, and can be applied to various wafer clamping scenarios.

[0038] In order to prevent the lifting arm 5 and / or the sensing element 6 and / or the contact end 51 from falling into the arc-shaped notch 2 and causing adverse effects on the entry of the wafer 4 into the arc-shaped notch 2, the lifting arm 1 has a second mounting groove 11 for accommodating the contact end 51.

[0039] The wafer pulling structure also includes a base 7, on which the aforementioned pulling arm 1 is connected. A limiting member 71 is connected to the base 7, and the spreading member 5 is concentrically and coaxially movably connected to the limiting member 71. Specifically, the limiting member 71 and the spreading member 5 are cylinder components; that is, a cylinder structure is connected to the base 7, and the cylinder drives the spreading member 5 to extend and retract. In this embodiment, a sensor 6 is disposed on the limiting member 71, which can sense the travel distance of the spreading member 5 relative to the limiting member 71.

[0040] For the setting of the second stroke, when the wafer 4 is not attached to the open end 3, the cylinder pushes the spreader 5 downward, and the sensor 6 detects the limit position of the cylinder pushing out the spreader 5 to obtain the second stroke and initialize the position of the spreader 5 in the wafer-free state.

[0041] In order to provide installation space for the limiting member 71 and / or the sensing member 6, the lifting arm 1 has a first mounting groove 12, in which the limiting member 71 and / or the sensing member 6 are located.

[0042] The working process of this invention is as follows: When the sensing element 6 is located at the lower end of the flat arm 5, and the wafer 4 is hung on the opening end 3 of the lifting arm 1, the wafer limiting detection unit 9 moves downward along the through channel 8 until the flat arm 5, with the contact end 51, abuts against the side wall of the wafer 4. At this time, the sensing element 6 senses that the wafer 4 is effectively clamped in the arc-shaped notch 2. At this time, the flat arm 5 and the opening end 3 cooperate to achieve a three-point stable clamping of the wafer 4. That is, the flat arm 5 not only serves to sense whether the wafer 4 is clamped, but also serves to clamp the wafer 4. When the wafer 4 needs to be removed from the arc-shaped notch 2, the flat arm 5 moves upward to reset. In another scenario, when the wafer 4 is not accurately hung on the opening end 3, the contact end 51 does not contact any object, the sensing element 6 cannot sense any object, and it is determined that there is no wafer 4 on the wafer lifting structure.

[0043] When the sensor 6 is positioned on the limiting member 71, and the wafer 4 is hung on the opening end 3 between the lifting arms 1, the wafer limiting detection unit 9 moves downward by a first stroke. The flat member 5, carrying the contact end 51 (at this time, the sensor is not required), abuts against the side wall of the wafer 4. At this time, the sensor 6 senses that the wafer 4 is effectively clamped in the arc-shaped notch 2. At this time, the flat member 5 and the opening end 3 cooperate to achieve a three-point stable clamping of the wafer 4. That is, the flat member 5 not only senses whether the wafer 4 is clamped, but also clamps the wafer 4. When the wafer 4 needs to be removed from the arc-shaped notch 2, the flat member 5 moves upward to reset. In another scenario, when the wafer 4 is not accurately hung on the opening end 3, the flat member 5 moves downward by a second stroke. This second stroke is greater than the first stroke, indicating that the contact end 51 is not blocked by the wafer 4. At this time, the sensor 6 senses that the wafer 4 is not effectively clamped in the arc-shaped notch 2.

[0044] The above specific embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

[0045] 1: Lifting arm 11: Second mounting slot 12: First mounting slot 2: Arc-shaped notch 3: Open end 4: Wafer 5: Carrying pole parts 51: Contact end 52: Receiving tank 6: Sensors 7: Base 71: Limiting component 8: Through passage 81: Limiting pipe 82: Widening Zone 9: Wafer Limit Detection Unit

Claims

1. A wafer pulling structure, comprising at least one pulling arm (1), an arc-shaped notch (2) formed by the pulling arm (1), and an opening end (3), wherein the inner diameter of the arc-shaped notch (2) is adapted to the outer diameter of a wafer (4), the width of the opening end (3) is smaller than the outer diameter of the wafer (4), and the wafer (4) is hung on the opening end (3), characterized in that: it further comprises a through channel (8) extending along the central axis of the arc-shaped notch (2), and a wafer positioning detection unit (9), wherein the through channel (8) is... The channel (8) is located inside the lifting arm (1), and the wafer positioning detection unit (9) is movably located in the through channel (8), and at least part of it can pass through the lifting arm (1) along the second direction and extend into the arc-shaped notch (2) to abut against the wafer (4). The through channel (8) has a limiting channel (81), and part of the wafer positioning detection unit (9) is located in the limiting channel (81) to form a limiting fit between the two in the first direction. The first direction and the second direction are perpendicular or tend to be perpendicular. The wafer positioning detection unit (9) includes a flat pole (5) movably disposed in the through channel (8) and a sensor (6) connected to the flat pole (5). The flat pole (5) can pass through the lifting arm (1) and extend into the arc-shaped notch (2) to abut against the wafer (4). The sensor (6) is used to sense whether the lifting arm (1) is holding the wafer (4). The lifting arm (1) has a first mounting groove (12). One end of the flat pole (5) is located in the first mounting groove (12), and the other end passes through the through channel (8) of the lifting arm (1) and extends into the arc-shaped notch (2). Part of the wafer positioning detection unit (9) is located in the first mounting groove (12). The flat pole (5) and the positioning pipe (81) form a third-direction positioning fit so that the flat pole (5) is located in the plane of the arc-shaped notch (2), so that the flat pole (5) plays the role of a flat pole that carries objects at both ends and limits the middle.

2. The wafer pulling structure as claimed in claim 1, characterized in that: the sensing element (6) is disposed at the end of the flat member (5) for sensing whether the flat member (5) is in contact with the wafer (4).

3. The wafer pulling structure as claimed in claim 1, characterized in that: the sensing element (6) is disposed on the side of the flat member (5) for sensing the distance of relative movement of the flat member (5) relative to the pulling arm (1), and the through channel (8) has an enlarged diameter area (82) for accommodating the sensing element (6).

4. The wafer pulling structure as claimed in claim 1, characterized in that: the end of the flat member (5) is connected to a contact end (51), which has a receiving groove (52), the opposite side walls of the receiving groove (52) being flared cones.

5. The wafer pulling structure as claimed in claim 4, characterized in that: a second mounting groove (11) for receiving a contact end (51) is provided between the pulling arms (1).

6. The wafer pulling structure as claimed in claim 1, characterized in that: the moving path of the flat member (5) coincides with or tends to coincide with the center line of the arc-shaped notch (2); the limiting channel (81) and part of the wafer limiting detection unit (9) form a third-direction limiting fit, so that the flat member (5) is located in the plane of the arc-shaped notch (2).

7. The wafer lifting structure as claimed in claim 6, characterized in that: the flat member (5) has at least a first stroke and a second stroke, when the flat member (5) travels the first stroke, it abuts against the outer wall of the wafer (4) to cooperate with the lifting arm (1) to clamp the wafer (4), and the second stroke is greater than the first stroke.

8. The wafer pulling structure as claimed in claim 1, characterized in that: it further includes a base (7), the pulling arm (1) is connected to the base (7); the base (7) is connected to a limiting member (71), and the flat member (5) is movably connected to the limiting member (71) in a concentric and coaxial manner.

9. The wafer pulling structure as claimed in claim 8, characterized in that: the pulling arm (1) has a first mounting groove (12), and the limiting member (71) is located in the first mounting groove (12).

10. The wafer pulling structure as claimed in claim 8, characterized in that: the flat member (5) and the limiting member (71) are parts of a cylinder.

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