Self-cleaning robot arm and wafer transfer device

Abstract

The application provides a self-cleaning mechanical arm and wafer conveying device, and relates to the technical field of semiconductor processing. The self-cleaning mechanical arm comprises an execution end, an electrostatic sensor and an ionization air nozzle. The execution end is provided with a pickup part, and the pickup part is used for picking up parts. The electrostatic sensor is arranged on the execution end and is used for detecting the amount of electrostatic charge on the pickup part. The ionization air nozzle is arranged on the execution end and is used for blowing air to the pickup part to remove electrostatic ions on the surface of the pickup part. In this way, the cleanliness of the mechanical arm is improved, the risk of wafer pollution is reduced, the wafer conveying efficiency and the wafer processing yield are improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor processing technology, and in particular to a self-cleaning robotic arm and a wafer transfer device. Background Technology

[0002] In wafer fabrication, wafers are removed from wafer cassettes and placed into appropriate processing equipment, such as etching machines, deposition machines, or bonding machines, using a wafer transport system. The wafer transport system, also called an Equipment Front End Module (EFEM), contains a robotic arm that directly contacts the wafers during transport. Frequent contact with the wafers generates static electricity in the robotic arm, which attracts surrounding particles. If this static electricity is not cleaned regularly, particle accumulation can occur, leading to abnormal machine conditions and machine downtime. Furthermore, it can affect wafer transport efficiency, contaminate the wafers, and reduce wafer packaging yield. Utility Model Content

[0003] The purpose of this invention is to provide a self-cleaning robotic arm and a wafer transfer device that can automatically clean the robotic arm, improve wafer transfer efficiency, reduce the risk of wafer contamination, and help improve wafer processing yield.

[0004] In a first aspect, this utility model provides a self-cleaning robotic arm, comprising: The execution end is provided with a picking unit, which is used to pick up parts; An electrostatic sensor is disposed at the actuator and is used to detect the amount of electrostatic charge on the pickup unit. An ionizing nozzle is disposed at the actuating end and is used to blow air onto the pickup unit to neutralize the electrostatic ions on the surface of the pickup unit.

[0005] In an optional embodiment, the actuator is provided with a receiving cavity, and the electrostatic sensor is disposed within the receiving cavity.

[0006] In an optional embodiment, the pickup unit has an adsorption surface for picking up parts; the electrostatic sensor is disposed in the accommodating cavity on the side near the adsorption surface.

[0007] In an optional embodiment, the adsorption surface is provided with a plurality of adsorption pores.

[0008] In an optional implementation, a master controller is also included, to which the electrostatic sensor is connected.

[0009] In an optional implementation, a cable is also included, one end of which is connected to the electrostatic sensor and the other end of which is connected to the main controller.

[0010] In an optional implementation, a microcontroller unit is also included, wherein the electrostatic sensor is connected to the microcontroller unit, and the microcontroller unit is connected to the main controller.

[0011] In an optional embodiment, it further includes a motion controller and a main arm connected to the actuator, the motion controller and the microcontroller unit being connected; both the motion controller and the microcontroller unit are located inside the main arm; the ionized nozzle is connected to the microcontroller unit.

[0012] In an optional embodiment, the actuator is provided with a base connected to the pickup unit, the ionization nozzle is disposed on the base, and the outlet of the ionization nozzle faces the center of the pickup unit.

[0013] Secondly, the present invention provides a wafer transfer device, including a self-cleaning robotic arm as described in any of the foregoing embodiments.

[0014] The self-cleaning robotic arm and wafer transfer device provided in this embodiment of the invention have the following advantages: The actuator is equipped with an electrostatic sensor and an ionizing nozzle. The electrostatic sensor detects the amount of electrostatic charge accumulated on the surface of the pickup section, while the ionizing nozzle blows air to remove electrostatic ions from the pickup section surface, thus achieving electrostatic dissipation. This reduces the adverse effects of electrostatic accumulation, improves the cleanliness of the pickup section surface, prevents wafer contamination, increases wafer transfer efficiency, and improves wafer processing yield.

[0015] The wafer transfer device provided in this embodiment includes the self-cleaning robotic arm described above, which can improve the cleanliness of the surface of the robotic arm's picking section, reduce the risk of wafer contamination, and improve the yield of wafer processing. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the control principle of the self-cleaning robotic arm provided in this embodiment of the utility model; Figure 2 A schematic diagram of the structure of the actuator of the self-cleaning robotic arm provided in an embodiment of this utility model; Figure 3Another view of the structure of the self-cleaning robotic arm's actuator connected to the main controller, provided in an embodiment of this utility model; Figure 4 A schematic diagram illustrating the application scenario of the self-cleaning robotic arm provided in this embodiment of the utility model; Figure 5 This is a schematic diagram of the ionizing air jetting from the ionizing nozzle of the self-cleaning robotic arm provided in an embodiment of the present invention.

[0018] Icons: 101-Wafer; 103-Wafer box; 1031-Cover; 110-Main arm; 120-Actuator; 121-Pick-up unit; 1211-Adsorption surface; 122-Adsorption hole; 123-Cavity; 124-Base; 131-Electrostatic sensor; 132-Cable; 133-Main controller; 141-Microcontroller unit; 142-Motion controller; 150-Ionizing nozzle. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 utility model based on the specific circumstances.

[0025] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] This utility model provides a self-cleaning robotic arm for picking up, transferring, and placing wafers. The self-cleaning method improves the cleanliness of the robotic arm surface, making the reliability and stability of wafer picking better and reducing the risk of wafer surface contamination.

[0027] Please combine Figure 1 and Figure 2The self-cleaning robotic arm includes a main arm 110 and an execution end 120 connected to the main arm 110. The execution end 120 is provided with a pickup section 121 and a base 124. The pickup section 121 is used to pick up parts. In this embodiment, the part is a wafer 101. In other embodiments, the pickup section 121 can also be used to pick up other parts, which is not specifically limited here. An electrostatic sensor 131 is provided on the pickup section 121 and can detect the amount of electrostatic charge on the pickup section 121. An ionizing nozzle 150 is provided on the base 124 and can be used to blow air onto the pickup section 121 to neutralize the electrostatic ions on the surface of the pickup section 121. By using the electrostatic sensor 131 to detect the amount of electrostatic charge accumulated on the surface of the pickup section 121, and using the airflow blown by the ionizing nozzle 150 to neutralize the electrostatic ions on the surface of the pickup section 121, the purpose of static dissipation is achieved. This helps to improve the cleanliness of the surface of the robotic arm's picking section 121, reduce the risk of wafer 101 contamination, and improve the wafer 101 transfer efficiency and wafer 101 processing yield.

[0028] Optionally, the pickup unit 121 is provided with an adsorption hole 122, which utilizes vacuum adsorption to pick up and transfer components such as wafers 101. It should be noted that the surface of the pickup unit 121 is prone to static electricity during frequent contact with the wafer 101. This static electricity attracts surrounding particles, leading to particle accumulation. Particle accumulation can disrupt the sealed environment between the pickup unit 121 and the wafer 101 or block the adsorption hole 122, resulting in a decrease or even failure of the vacuum adsorption force. This can cause the wafer 101 to fall or shift during transport, leading to equipment downtime. Furthermore, particle accumulation can contaminate the surface of the wafer 101. When the wafer 101 enters the reaction chamber for etching, deposition, or other processes, the contaminated particles on its surface can reduce process uniformity, causing incomplete etching, deposition layer defects, and other process abnormalities, affecting processing yield. In this embodiment, static electricity on the surface of the pickup unit 121 can be dissipated, thereby maintaining the cleanliness of the pickup unit 121 surface and preventing the aforementioned adverse phenomena during robotic arm operation.

[0029] Please combine Figure 3Optionally, the pickup unit 121 has an adsorption surface 1211 for picking up parts, and the adsorption surface 1211 is used to contact the wafer 101. The adsorption surface 1211 is provided with a plurality of adsorption holes 122. There may be one or more adsorption holes 122. In this embodiment, there are three adsorption holes 122. The pickup unit 121 is provided with a receiving cavity 123, and the receiving cavity 123 and the adsorption holes 122 are independent of each other and do not interfere with each other. The electrostatic sensor 131 is disposed in the receiving cavity 123, and the electrostatic sensor 131 is disposed on the side of the receiving cavity 123 close to the adsorption surface 1211. This arrangement can both detect the change of electric field on the surface of the pickup unit 121 and indirectly measure the amount of electrostatic charge accumulated on the adsorption surface 1211, and avoid direct contact with the adsorption surface 1211. This can effectively avoid the influence of the electrostatic sensor 131 on the cleanliness of the adsorption surface 1211 and the surface of the wafer 101, and also avoid the electrostatic sensor 131 itself from being contaminated. While maintaining the detection sensitivity of the electrostatic sensor 131, the reliable operation of the pickup unit 121 is not affected.

[0030] The self-cleaning robotic arm also includes a main controller 133. An electrostatic sensor 131 is connected to the main controller 133, which can be an electrical connection or a communication connection. In this embodiment, the electrostatic sensor 131 and the main controller 133 are connected by a cable 132. One end of the cable 132 is connected to the electrostatic sensor 131, and the other end is connected to the main controller 133. In this embodiment, the end of the cable 132 furthest from the electrostatic sensor 131 extends outside the actuator 120 and is connected to the main controller 133. This allows the signal detected by the electrostatic sensor 131 to be transmitted to the main controller 133, facilitating the main controller 133's control of the ionizing nozzle 150 based on the electric field changes detected by the electrostatic sensor 131. Of course, in other embodiments, the electrostatic sensor 131 and the main controller 133 can also be connected wirelessly; this is not specifically limited here.

[0031] Optionally, the self-cleaning robotic arm also includes a microcontroller unit 141, with an electrostatic sensor 131 connected to the microcontroller unit 141, and the microcontroller unit 141 connected to the main controller 133. The microcontroller unit 141 adopts an embedded design and is located within the main arm 110, resulting in a compact structure. The microcontroller unit 141 can be integrated with other control units on the main arm 110. Of course, the microcontroller unit 141 can also be located outside the main arm 110; no specific limitation is made here.

[0032] Optionally, the main arm 110 is also equipped with a motion controller 142, which is connected to a microcontroller unit 141; the ionizing nozzle 150 is also connected to the microcontroller unit 141. When the motion controller 142 is in an idle state, the microcontroller unit 141 controls the ionizing nozzle 150 to blow air. The motion controller 142 can be used to control the movement of the actuator 120 to transfer components such as the wafer 101. In this embodiment, cleaning of the pickup unit 121 should be performed when the actuator 120 is in an idle state, i.e., when no components are being transferred, to avoid the cleaning action affecting or interfering with the transfer of the wafer 101. The microcontroller unit 141 is connected to the motion controller 142 and can detect whether the motion controller 142 is in an idle or working state. When the motion controller 142 is idle, the ionizing nozzle 150 is activated, blowing air onto the pickup unit 121 to sweep away dirt from its surface, dissipate static electricity, and improve the cleanliness of the adsorption surface 1211. The activation command for the ionizing nozzle 150 can be issued by the main controller 133 or by the microcontroller unit 141.

[0033] Please combine Figure 4 In this embodiment, both the motion controller 142 and the microcontroller unit 141 are housed within the main arm 110, resulting in a compact structure. The main arm 110 effectively protects the motion controller 142 and the microcontroller unit 141, extending their service life. Optionally, the blowing air pressure of the ionizing nozzle 150 is 0.05 bar to 0.5 bar. It is understood that during EFEM operation, the EFEM itself has a laminar flow structure to ensure a clean environment within the EFEM, preventing contamination of the wafer 101 and preventing external contaminants from entering the EFEM. The air pressure blown out by the ionizing nozzle 150 must be much lower than the air pressure of the laminar flow structure within the EFEM itself to avoid disrupting the stability of the laminar flow and preventing particles from diffusing to other areas. Experimental verification shows that an air pressure of 0.07 bar to 0.34 bar is sufficient to remove submicron-sized particles while maintaining airflow balance within the EFEM.

[0034] In this embodiment, the ionization nozzle 150 sprays nitrogen gas that has been treated by an ionizer and neutralized with both positive and negative ions. The ionized air from the ionization nozzle 150 provides an equal amount of positive and negative ions to neutralize the opposite charges on the surface of the pickup unit 121, eliminating the electrostatic field. Furthermore, the nitrogen gas flow blows the particles that have been neutralized by the ionized air (eliminating electrostatic adsorption) off the surface and carries them away through the lower negative pressure exhaust system of the EFEM, ensuring the cleanliness of the entire EFEM environment.

[0035] It should be noted that, Figure 4In this wafer cassette 103, an openable cover 1031 is included, and a wafer 101 is placed inside the wafer cassette 103. During transport, the cover 1031 remains closed. The cover 1031 can be opened when the wafer 101 is picked up or placed.

[0036] Please combine Figure 5 Optionally, the outlet of the ionization nozzle 150 is oriented towards the center of the pickup section 121. This results in a large blowing area, which can effectively and thoroughly blow away particles on the adsorption surface 1211 and dissipate the electrostatic field on the adsorption surface 1211, thereby improving cleaning efficiency and cleaning effect.

[0037] The working principle of the self-cleaning robotic arm provided in this embodiment of the invention is as follows: After each film fetch, transmission, and placement, the execution terminal 120 returns to its initial position and waits for the next film fetch.

[0038] Upon returning to the initial position, when the motion controller 142 is idle, the microcontroller unit 141 or the main controller 133 activates the ionizing nozzle 150 to purge the pickup unit 121. The ionizing air neutralizes the static electricity on the adsorption surface 1211 and blows particulate contaminants away from it. The duration of each purging cycle can be flexibly set.

[0039] The electrostatic sensor 131 continuously and in real-time detects changes in the electric field of the adsorption surface 1211. During wafer pick-up, wafer feeding, wafer placement, and the initial position, the accumulation of electrostatic charge on the adsorption surface 1211 is monitored in real-time, and the charge quantity is indirectly measured by sensing changes in the electric field of the adsorption surface 1211. If the detected electrostatic voltage on the adsorption surface 1211 is greater than or equal to a preset value, the purging time of the ionizing nozzle 150 is extended in the next purging cycle until the detected electrostatic voltage on the adsorption surface 1211 is less than the preset value. This preset value can be 300V, 500V, or 600V, and can be flexibly set according to actual conditions. If the electrostatic voltage on the adsorption surface 1211 is still greater than the preset value after prolonged purging by the ionizing nozzle 150, manual cleaning is required.

[0040] It should be noted that when the electrostatic voltage reaches 500V, the electrostatic charge significantly increases the adsorption of submicron particles. At this point, the lateral shear force of the air jet from the ionization nozzle 150 may be insufficient to remove surface particles, increasing the difficulty of cleaning. In fields such as wafer 101 manufacturing and disk manufacturing, ±500V has long been considered an important control limit. For example, in the sensitive process areas of gallium nitride chips, it is required to control the electrostatic charge below 500V to reduce risks. In this embodiment, the preset value is preferably 500V, which can balance the prevention of particle contamination and avoid the problem of system oversensitivity.

[0041] In some implementations, the number of sheets fed by the robotic arm can be counted. When the number of sheets fed reaches a preset number, the ionizing nozzle 150 needs to be used for a long time to blow clean, or manual cleaning is required to ensure the cleanliness of the surface of the pickup section 121. Alternatively, after the robotic arm has been running for a preset time, the ionizing nozzle 150 needs to be used for a long time to blow clean, or manual cleaning is required.

[0042] Optionally, the main arm 110 is also equipped with an alarm. When the detected electrostatic voltage is greater than or equal to a preset value, or the number of sheets fed is greater than or equal to a preset quantity, or the running time exceeds a preset duration, the alarm will sound to remind the user to manually clean the adsorption surface 1211. After each manual cleaning, the number of sheets fed is reset.

[0043] In this embodiment, the ionized air blown out by the ionization nozzle 150 is used to sweep the surface of the pickup section 121, eliminating electrostatic ions and accumulated particulate contaminants from a physical perspective. Furthermore, an electrostatic sensor 131 is used for real-time, continuous monitoring, enabling closed-loop control of detection, sweeping, and further ensuring the effectiveness of the sweeping action. This further eliminates electrostatic ions and particles on the adsorption surface 1211, improving cleanliness.

[0044] This invention provides a wafer transfer device, including a self-cleaning robotic arm as described in any of the foregoing embodiments. The wafer transfer device can be applied to, but is not limited to, etching machines, deposition machines, or bonding machines. This self-cleaning robotic arm can transfer wafers 101 back and forth between the wafer cassette 103 and the aforementioned equipment, achieving efficient and reliable transfer of wafers 101, which is beneficial for improving processing efficiency and yield.

[0045] In summary, the self-cleaning robotic arm and wafer transfer device provided in this embodiment of the present invention have the following beneficial effects, including: The actuator 120 of the main arm 110 is equipped with an electrostatic sensor 131 and an ionizing nozzle 150. The electrostatic sensor 131 can detect the amount of electrostatic charge accumulated on the surface of the pickup section 121, and the ionizing nozzle 150 can blow out airflow to neutralize the electrostatic ions on the surface of the pickup section 121, thereby achieving the purpose of electrostatic dissipation. This can reduce the adverse effects of electrostatic accumulation, help reduce particle adsorption caused by electrostatic accumulation, improve the cleanliness of the pickup section 121 surface, prevent wafer 101 from being contaminated, improve the transfer efficiency of wafer 101 and improve the processing yield of wafer 101, and also help reduce the number of downtime cleanings, reduce the frequency of equipment downtime cleaning, and improve the working efficiency of the equipment. The motion controller 142 and the microcontroller unit 141 are located inside the main arm 110, and the electrostatic sensor 131 is located inside the receiving cavity 123 of the pickup section 121. The structure is compact and provides good protection for the electrostatic sensor 131.

[0046] The wafer transfer device provided in this embodiment of the present invention includes the self-cleaning robotic arm described above, which can improve the cleanliness of the surface of the picking part 121 of the robotic arm, reduce the risk of wafer 101 being contaminated, and improve the yield of wafer 101 processing.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of this utility model.

Claims

1. A self-cleaning robotic arm, characterized in that, include: The execution end is provided with a picking unit, which is used to pick up parts; An electrostatic sensor is disposed at the actuator and is used to detect the amount of electrostatic charge on the pickup unit. An ionization nozzle is disposed at the actuating end and is used to blow air onto the pickup unit to remove electrostatic ions from the surface of the pickup unit.

2. The self-cleaning robotic arm according to claim 1, characterized in that, The actuator is provided with a accommodating cavity, and the electrostatic sensor is disposed in the accommodating cavity.

3. The self-cleaning robotic arm according to claim 2, characterized in that, The pickup unit has an adsorption surface for picking up parts; the electrostatic sensor is located inside the accommodating cavity on the side near the adsorption surface.

4. The self-cleaning robotic arm according to claim 3, characterized in that, The adsorption surface is provided with a number of adsorption pores.

5. The self-cleaning robotic arm according to claim 1, characterized in that, It also includes a main controller, to which the electrostatic sensor is connected.

6. The self-cleaning robotic arm according to claim 5, characterized in that, It also includes a cable, one end of which is connected to the electrostatic sensor and the other end of which is connected to the main controller.

7. The self-cleaning robotic arm according to claim 5, characterized in that, It also includes a microcontroller unit, the electrostatic sensor is connected to the microcontroller unit, and the microcontroller unit is connected to the main controller.

8. The self-cleaning robotic arm according to claim 7, characterized in that, It also includes a motion controller and a main arm connected to the actuator, the motion controller and the microcontroller unit are connected; both the motion controller and the microcontroller unit are located inside the main arm; the ionized nozzle is connected to the microcontroller unit.

9. The self-cleaning robotic arm according to any one of claims 1 to 8, characterized in that, The actuator is provided with a base connected to the pickup unit, the ionization nozzle is provided on the base, and the outlet of the ionization nozzle faces the center of the pickup unit.

10. A wafer transfer device, characterized in that, Including the self-cleaning robotic arm as described in any one of claims 1 to 9.

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