Sealing ring, wafer carrying arm and wafer carrying device

Abstract

The invention provides a sealing ring, a wafer carrying arm and a wafer carrying device. The sealing ring is used for being installed on a vacuum adsorption part of a wafer carrying arm to keep the vacuum state between the vacuum adsorption part and a wafer adsorbed by the vacuum adsorption part, and is characterized in that a plurality of protrusions are arranged on the surface, making contact with the wafer, of the sealing ring. By adopting the sealing ring of the embodiment, when a wafer is carried by a wafer carrying arm, the friction force on the surface of the sealing ring can be increased, and even if the carried wafer is heated to a high temperature, the sealing ring can be prevented from sticking to the wafer, so that the wafer can be smoothly transferred.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a sealing ring installed on a wafer conveying arm, a wafer conveying arm and a wafer conveying device. Background Art

[0002] When processing wafers, it is usually necessary to use a wafer transport device to transport the wafers to be processed to a processing container, and then move the wafers out of the processing container after a predetermined process is performed on the wafers.

[0003] Figure 6 The figure shows a wafer transfer arm 50 of a wafer transfer device in the prior art. The wafer transfer arm 50 includes an arm body 50a and two branched arms 50b and 50c extending in a U shape. Three vacuum adsorption parts 52 are provided on the surface of the wafer transfer arm 50. The vacuum adsorption parts 52 are formed by forming an opening 53 on the surface of the wafer transfer arm 50, and a hole 54 is formed on the bottom surface of the opening 53. Each hole 54 is connected to a vacuum device 60 through a gas passage not shown in the figure. When the wafer is transferred by the wafer transfer arm 50, the vacuum device 60 evacuates the vacuum adsorption part 52 through the gas passage so that the vacuum adsorption part 52 adsorbs the wafer and prevents the wafer from sliding.

[0004] As wafers grow in size, the warpage of wafers increases, which can easily cause vacuum loss during wafer handling by the wafer handling arm, affecting the adsorption effect of the wafers. In order to obtain a better adsorption effect, a sealing ring (also called a sealing ring) made of a flexible material (e.g., silicone rubber) is usually installed in the vacuum adsorption part. Figure 7 Yes means Figure 6 A schematic cross-sectional view of a vacuum suction section of a wafer handling arm. Figure 7 The sealing ring 51 is placed in the opening 53 of the vacuum suction part 52 shown. Summary of the invention

[0005] Figure 6 , 7 When the wafer transport arm 50 shown is transporting a wafer W at room temperature, the sealing ring 51 can well seal the vacuum adsorption part 52 and maintain the vacuum degree of the vacuum adsorption part 52; when the wafer W is unloaded from the wafer transport arm 50, there is generally no adhesion between the wafer W and the sealing ring 51. However, when transporting a wafer W heated to a high temperature (for example, above 300°C), the viscosity of the surface of the sealing ring 51 will change after contacting the high-temperature wafer W. In this case, when the wafer W is transferred from the wafer transport arm 50, the sealing ring 51 will stick to the wafer W, and in severe cases, the wafer W will fall to the ground.

[0006] The inventor of the present application has found that when a sealing ring is formed of silicone rubber with high hardness (for example, Shore hardness of 90 or more), its surface viscosity can be effectively reduced, but in this case, the friction force on the surface of the sealing ring becomes smaller. When the wafer W is unloaded from the wafer transfer arm, there is a problem that the wafer W slides to a place other than the intended destination due to inertia because the friction force on the surface of the sealing ring is small.

[0007] The present invention is completed to solve the above-mentioned technical problems, and its purpose is to provide a sealing ring, a wafer transport arm and a wafer transport device that can increase the friction force on the surface of the sealing ring and prevent the wafer from sticking when transporting high-temperature wafers.

[0008] The present invention provides a sealing ring, which is used to be installed on the vacuum adsorption part of a wafer transport arm to maintain the vacuum state between the vacuum adsorption part and the wafer adsorbed thereon. The sealing ring is characterized in that a plurality of protrusions are arranged on the surface of the sealing ring in contact with the wafer.

[0009] By using the sealing ring of this embodiment, the friction force on the surface of the sealing ring can be increased, and when a high-temperature wafer is transported, the sealing ring can be prevented from sticking to the wafer, thereby smoothly transferring the wafer.

[0010] In one embodiment, the protrusion and the seal ring are integrally formed of the same material.

[0011] According to the seal ring of this embodiment, the seal ring can be easily formed.

[0012] In one embodiment, the protrusion and the seal ring are formed of silicone rubber.

[0013] In one embodiment, the protrusion is provided on a surface of the seal ring opposite to a surface in contact with the wafer.

[0014] With the seal ring of this embodiment, when the seal ring is placed in the opening of the vacuum suction part, it is not necessary to check the front and back of the seal ring, and it can be ensured that the surface of the seal ring in contact with the wafer always forms a protrusion.

[0015] In one embodiment, the plurality of protrusions are evenly arranged on the surface of the sealing ring.

[0016] In one embodiment, the protrusion is in any of a spherical, cylindrical and conical shape.

[0017] In one embodiment, a height of the protrusion from the surface of the seal ring is 0.2 mm or less.

[0018] In one embodiment, the sealing ring is obtained by placing a liquid material in a cavity of a mold and then cooling and hardening the liquid material, the cavity has a space corresponding to the sealing ring, and the surface of the cavity has a recess corresponding to the protrusion.

[0019] The present invention provides a wafer transport arm, characterized in that it has a vacuum adsorption portion, which includes an opening formed on the surface of the wafer transport arm, the opening is connected to the vacuum pumping system, and a sealing ring of any of the above-mentioned methods is placed in the opening.

[0020] By adopting the wafer transfer arm of this embodiment, the friction force on the surface of the sealing ring can be increased, and when transferring high-temperature wafers, the sealing ring can be prevented from sticking to the wafers, thereby smoothly transferring the wafers.

[0021] The present invention provides a type of wafer transport device, characterized in that it includes: a wafer transport arm of the above type; a mechanical arm connected to the wafer transport arm; and a driving mechanism that drives the mechanical arm to drive the wafer transport arm to move.

[0022] According to the wafer transport device of the present invention, the friction force on the surface of the sealing ring can be increased, and when transporting a high-temperature wafer, the sealing ring can be prevented from sticking to the wafer, thereby smoothly transferring the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figures show a wafer transport device according to Embodiment 1 of the present invention, wherein (a) is a perspective view of the wafer transport device, (b) is a cross-sectional view of the wafer transport device, and (c) is another cross-sectional view of the wafer transport device.

[0024] Figure 2 The figures show a wafer transfer arm according to Embodiment 1 of the present invention, wherein (a) is a stereoscopic view of the wafer transfer arm, (b) is a top view of the wafer transfer arm, and (c) is a side view of a vacuum adsorption portion of the wafer transfer arm.

[0025] Figure 3 The drawings show a seal ring according to Embodiment 1 of the present invention, wherein (a) is a perspective view of the seal ring, (b) is a top view of the seal ring, and (c) is a cross-sectional view taken along the line AA of (b).

[0026] Figure 4 It is a schematic diagram of the protrusion formed on the seal ring according to the first embodiment of the present invention.

[0027] Figure 5 It is a schematic diagram of a protrusion formed on the seal ring according to the second embodiment of the present invention.

[0028] Figure 6Schematic diagram of a wafer transfer arm according to the prior art.

[0029] Figure 7 The figure is a cross-sectional schematic diagram showing a vacuum suction portion of a wafer transfer arm in the related art. DETAILED DESCRIPTION

[0030] Hereinafter, a preferred mode for carrying out the present invention will be described. However, the following embodiments are merely illustrative, and the present invention is not limited to the following embodiments.

[0031] In addition, it should be understood that the drawings used in the following embodiments are schematic and do not represent the actual dimensions and sizes of the sealing ring, wafer transfer arm and wafer transfer device of the present invention.

[0032] Implementation Method 1

[0033] Figure 1 The figures show a wafer transport device according to Embodiment 1 of the present invention, wherein (a) is a perspective view of the wafer transport device, (b) is a cross-sectional view of the wafer transport device, and (c) is another cross-sectional view of the wafer transport device.

[0034] like Figure 1 As shown, the wafer transfer device 10 of the present invention includes two wafer transfer arms 11A and 11B, four rotating arms 12 to 14, and a driving unit 16 for moving the wafer transfer arm 11 by driving the rotating arms 12 to 14. The rotating arms 12 to 14 described here correspond to the robot arms in the present invention.

[0035] Specifically, the front end of the upper wafer transfer arm 11A can absorb and support the wafer W, and the root end is connected to the front end of the rotating arm 13, and the wafer transfer arm 11A can rotate around the front end of the rotating arm 13. The root end of the rotating arm 13 is connected to the front end of the rotating arm 15, and the rotating arm 13 can rotate around the front end of the rotating arm 15. The root end of the rotating arm 15 is connected to the driving unit 16, and the rotating arm 15 can rotate around the driving unit 16. A motor (not shown) for driving the rotating arms 12 to 14 to rotate is installed in the driving unit 16.

[0036] The structure of the lower wafer transport arm 11B is substantially the same as that of the upper wafer transport arm 11A. Specifically, the front end of the lower wafer transport arm 11B can absorb and support the wafer W, and the root end is connected to the front end of the rotating arm 12, and the wafer transport arm 11B can rotate around the front end of the rotating arm 12. The root end of the rotating arm 12 is connected to the front end of the rotating arm 14, and the rotating arm 12 can rotate around the front end of the rotating arm 14. The root end of the rotating arm 14 is connected to the driving unit 16, and the rotating arm 14 can rotate around the driving unit 16.

[0037] As described above, the wafer transport device 10 of the present invention includes two wafer transport arms 11A and 11B, but is not limited thereto. The wafer transport device 10 of the present invention may also include only one wafer transport arm, or include more than three wafer transport arms. For example, when only the wafer transport arm 11A is included but not the wafer transport arm 11B, the rotating arms 12 and 14 for moving the wafer transport arm 11B may also be omitted.

[0038] In the wafer transfer device 10 of the present invention, the structures of the wafer transfer arm 11A and the wafer transfer arm 11B are substantially the same. Therefore, in the following description, the wafer transfer arm 11A and the wafer transfer arm 11B are collectively referred to as the wafer transfer arm 11.

[0039] The wafer transfer apparatus 10 of the present invention can smoothly transfer wafers to a predetermined position.

[0040] Figure 2 The figures show a wafer transfer arm according to Embodiment 1 of the present invention, wherein (a) is a stereoscopic view of the wafer transfer arm, (b) is a top view of the wafer transfer arm, and (c) is a side view of a vacuum adsorption portion of the wafer transfer arm.

[0041] like Figure 2 As shown, the wafer transport arm 11 of the present invention includes an arm body 11a and two bifurcated arms 11b and 11c extending in a U-shape from the front end of the arm body 11a. Two vacuum adsorption parts 2 are provided on each of the bifurcated arms 11b and 11c, and a total of four vacuum adsorption parts 2 are provided. The vacuum adsorption part 2 includes an opening formed on the upper surface of the wafer transport arm 11, and a hole (not shown) connected to a vacuum pumping system (not shown) is formed in the central part of the bottom surface of the opening. In the present embodiment, the wafer transport arm 11 is made of a ceramic material.

[0042] The sealing ring 1 of the present invention is placed in the opening of the vacuum suction part 2. When the wafer W is supported on the wafer transfer arm 11, a vacuum can be formed between the bottom surface of the wafer W and the wafer transfer arm 11 (more specifically, the vacuum suction part 2) by vacuuming the vacuum system, so that the vacuum suction part 2 firmly adsorbs the wafer W to prevent it from sliding or falling.

[0043] As described above, the wafer transfer arm 11 of the present invention has four vacuum suction units 2 , but the present invention is not limited thereto. The wafer transfer arm 11 of the present invention may also have two, three, or five or more vacuum suction units 2 .

[0044] When the wafer transport arm 11 has two vacuum suction units 2, one vacuum suction unit 2 may be provided on each of the bifurcated arms 11b and 11c. When the wafer transport arm 11 has three vacuum suction units 2, one vacuum suction unit 2 may be provided on each of the bifurcated arms 11b and 11c, and one vacuum suction unit 2 may be provided at the front end of the arm body 11a (the portion close to the bifurcated arms 11b and 11c).

[0045] Figure 3 The drawings show a seal ring according to Embodiment 1 of the present invention, wherein (a) is a perspective view of the seal ring, (b) is a top view of the seal ring, and (c) is a cross-sectional view taken along the line AA of (b). Figure 4 It is a schematic diagram of the protrusion formed on the seal ring according to the first embodiment of the present invention.

[0046] The sealing ring 1 of this embodiment is used to be mounted on the vacuum suction part 2 of the wafer transfer arm 11 to maintain the vacuum state between the vacuum suction part 2 and the suctioned wafer W. A plurality of protrusions 1a are provided on substantially the entire surface 1b of the sealing ring 1. The height h of the protrusions 1a from the surface 1b is 0.02 mm.

[0047] The sealing ring 1 is formed of a flexible material. In this embodiment, as an example, the flexible material is silicone rubber. The sealing ring 1 is donut-shaped, and its inner diameter d1 is 4.47 mm and its outer diameter d2 is 8.03 mm when viewed from above. Figure 3 In the cross section of the seal ring 1 shown in (c), the thickness t of the seal ring 1 is 1.78 mm.

[0048] exist Figure 3 In the figure, the portion of the surface 1b of the sealing ring 1 having the protrusion 1a includes not only the surface of the sealing ring 1 in contact with the wafer W (referred to as the contact surface), but also the surface of the sealing ring 1 on the opposite side of the contact surface (referred to as the non-contact surface).

[0049] By providing protrusions on both the contact surface and the non-contact surface of the sealing ring 1, when the sealing ring 1 is placed in the opening of the vacuum adsorption part 2, it is possible to ensure that the protrusion 1a is always formed on the surface of the sealing ring 1 that contacts the wafer W without specifically confirming the front and back sides of the sealing ring 1.

[0050] In this embodiment, if Figure 3 As shown, 50 circles of protrusions 1a are formed on the surface 1b of the sealing ring 1, and each circle has the same spacing and contains the same number of protrusions 1a, so that the protrusions 1a are evenly distributed on the surface 1b of the sealing ring 1.

[0051] Next, a method for forming the seal ring 1 according to the present embodiment will be described.

[0052] The difference between the seal ring 1 of this embodiment and the seal ring 51 of the prior art is that the protrusions 1a are formed on the surface 1b. Therefore, the method for forming the seal ring 1 of this embodiment can refer to the method for forming the seal ring 51 of the prior art.

[0053] In the prior art, the sealing ring 51 is obtained by placing liquid silicone rubber as a liquid material into a cavity of a mold (hereinafter referred to as a conventional mold) and then cooling and hardening the liquid silicone rubber. The cavity has a space corresponding to the sealing ring 51 .

[0054] When forming the sealing ring 1 of the present embodiment, firstly, the inner surface of the cavity of the existing mold is irradiated with laser, and the inner surface is ablated to form recesses corresponding to the protrusions 1a of the sealing ring 1, thereby obtaining the mold required for forming the sealing ring 1 of the present embodiment (hereinafter referred to as the mold of the present invention). The type of irradiated laser is not limited, and it can be laser irradiated by a fiber laser or laser irradiated by a carbon dioxide laser. The power of the laser is not particularly limited, as long as it can ablate recesses corresponding to the shapes of the protrusions 1a on the inner surface of the cavity of the above-mentioned mold.

[0055] After the mold of the present invention is obtained, liquid silicone rubber is placed in the cavity of the mold of the present invention and cooled and hardened. The cooled and hardened sealing ring is taken out to obtain the sealing ring 1 of the present embodiment.

[0056] Next, effects of the wafer transfer arm 11 and the wafer transfer device 10 to which the seal ring 1 according to the present embodiment is mounted will be described.

[0057] First, the inventor used the wafer transfer arm 50 of the prior art to transfer the wafer W heated to 300°C to a predetermined position. The inventor performed such transfer 100 times and found that adhesion occurred between the sealing ring 51 and the wafer W 90 times. The adhesion mentioned here refers to the phenomenon that the wafer W and the sealing ring cannot be separated smoothly when the wafer W is removed from the wafer transfer arm.

[0058] Furthermore, the inventors used a wafer transfer arm with a seal ring made of high-hardness silicone rubber to transfer room-temperature wafers W and unloaded the wafers W to a predetermined location. The inventors performed such transfers 100 times and found that 96 times the wafers W slipped out of the predetermined destination due to inertia.

[0059] Then, the inventor used the wafer handling device 10 (wafer handling arm 11) of the present invention to carry the wafer W heated to 300°C and transported the wafer W to a specified position. The inventor also performed such handling 100 times and found that no adhesion occurred between the sealing ring 1 and the wafer W. In addition, the inventor also confirmed that when the wafer W heated to 300°C was transported using the wafer handling device 10 (wafer handling arm 11) of the present invention, the wafer W was firmly adsorbed on the wafer handling arm 11, and there was no significant decrease in the vacuum degree between the wafer W and the wafer handling arm 11.

[0060] Furthermore, the inventors used the wafer transfer device 10 (wafer transfer arm 11) of the present invention to transfer a room temperature wafer W and unload the wafer W to a predetermined position. The inventors performed such transfer 100 times and found no case where the wafer W slipped out of the predetermined destination due to inertia.

[0061] It can be seen from this that the use of the sealing ring 1, the wafer conveying arm 11 and the wafer conveying device 10 of the present invention can increase the friction force on the surface of the sealing ring, and when conveying the wafer W heated to a high temperature, it is possible to prevent adhesion between the wafer W and the wafer conveying arm 11 (more specifically, the sealing ring), thereby enabling smooth conveyance of the wafer.

[0062] In the present embodiment, the protrusions 1a are formed uniformly and regularly on the surface of the sealing ring 1, but the present invention is not limited thereto, and the protrusions 1a may be formed non-uniformly and / or irregularly on the surface of the sealing ring 1. As long as the protrusions 1a are formed on the surface of the sealing ring 1, the friction force on the surface of the sealing ring can be increased accordingly, and the adhesion between the wafer W and the wafer transfer arm 11 (more specifically, the sealing ring) can be reduced.

[0063] In this embodiment, the height of the protrusion 1a from the surface 1b of the sealing ring 1 (hereinafter referred to as the height of the protrusion 1a) is 0.02 mm. However, this is not limited to this, and the height of the protrusion 1a may also be other values. As the height of the protrusion 1a increases, there is a risk that external air enters the vacuum adsorption part 2 from the gap between the wafer W and the sealing ring 1, causing the vacuum adsorption part 2 to lose vacuum and the adsorption force to decrease.

[0064] Therefore, the height of the protrusion 1a can be selected without affecting the vacuum suction unit 2 to firmly suck the wafer W. The inventors have confirmed through experiments that when the height of the protrusion 1a is 0.2 mm or less, the vacuum suction unit 2 hardly affects the suction of the wafer W.

[0065] In this embodiment, if Figure 4 As shown, the protrusion 1a of the seal ring 1 is formed in a hemispherical shape. However, the present invention is not limited thereto, and the protrusion 1a of the seal ring 1 may also be in other shapes such as a columnar shape or a conical shape.

[0066] Implementation Method 2

[0067] Figure 5 Schematic diagram of a protrusion formed on a seal ring according to Embodiment 2 of the present invention. Figure 3 The following description will focus on the differences between the seal ring of the second embodiment and the seal ring of the first embodiment, and the description of the same parts will be omitted.

[0068] In the first embodiment, the portion of the surface 1b of the sealing ring 1 where the protrusion 1a is provided includes not only the surface of the sealing ring 1 in contact with the wafer W (referred to as the contact surface), but also the surface of the sealing ring 1 opposite to the contact surface (referred to as the non-contact surface).

[0069] In the second embodiment, Figure 5 As shown, only the contact surface of the sealing ring 1 is provided with the protrusion 1 a , and the non-contact surface of the sealing ring 1 is not provided with the protrusion 1 a .

[0070] The sealing ring 1 of this embodiment can increase the friction force on the surface of the sealing ring, as in the first embodiment, and when transporting a wafer W heated to a high temperature, it can prevent adhesion between the wafer W and the wafer transport arm 11 (more specifically, the sealing ring), as in the first embodiment, thereby enabling smooth transport of the wafer; in addition, it can also enable the sealing ring 1 to be in good contact with the bottom surface of the opening of the vacuum adsorption portion 2.

[0071] The sealing ring, wafer conveying arm and wafer conveying device of embodiments 1 and 2 are described above, but these descriptions are made for easy understanding of the present invention. The sealing ring, wafer conveying arm and wafer conveying device of the present invention are not limited to the structures of the above-mentioned embodiments 1 and 2, and various modifications can be made on this basis.

[0072] For example, in embodiments 1 and 2, the sealing ring 1 is obtained by placing liquid silicone rubber in a cavity of a mold (a recess corresponding to each protrusion 1a of the sealing ring 1 is formed on the inner surface of the cavity) and cooling and hardening the liquid silicone rubber, and the sealing ring 1 and the protrusion 1a thus obtained are formed integrally from the same material. However, the present invention is not limited to this, and a protrusion having the same shape and size as the protrusion 1a can also be attached to the surface of the sealing ring of the prior art to obtain the sealing ring of the present invention. In addition, the material of the protrusion is not limited to the same material as that of the existing sealing ring, and the two can also be different materials.

[0073] Furthermore, the material of the seal ring 1 is not limited to silicone rubber, and may be other flexible materials.

Claims

1. A sealing ring, which is used to be installed on a vacuum suction part of a wafer handling arm to maintain a vacuum state between the vacuum suction part and the wafer sucked thereon, wherein the sealing ring is characterized in that: A plurality of protrusions are provided on a surface of the sealing ring that contacts the wafer.

2. The sealing ring according to claim 1, characterized in that: The protrusion and the sealing ring are integrally formed of the same material.

3. The sealing ring according to claim 2, characterized in that: The protrusion and the sealing ring are formed of silicone rubber.

4. The sealing ring according to claim 1, characterized in that: The protrusion is provided on a surface of the seal ring opposite to a surface in contact with the wafer.

5. The sealing ring according to claim 1, characterized in that: The plurality of protrusions are evenly arranged on the surface of the sealing ring.

6. The sealing ring according to claim 1, characterized in that: The protrusion may be in any of a spherical, cylindrical and conical shape.

7. The sealing ring according to claim 1, characterized in that: The height of the protrusion from the surface of the seal ring is 0.2 mm or less.

8. The sealing ring according to claim 1, characterized in that: The sealing ring is obtained by placing a liquid material into a cavity of a mold and then cooling and hardening the liquid material. The cavity has a space corresponding to the sealing ring, and a surface of the cavity has a recess corresponding to the protrusion.

9. A wafer handling arm, characterized in that: The wafer transport arm has a vacuum adsorption portion, which includes an opening formed on the surface of the wafer transport arm, and the opening is connected to the vacuum pumping system. The sealing ring according to any one of claims 1 to 8 is placed in the opening.

10. A wafer transport device, characterized in that: include: The wafer handling arm according to claim 9; a robotic arm connected to the wafer handling arm; and A driving mechanism drives the robotic arm to drive the wafer transport arm to move.

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