Wafer conveying method and mechanical arm

Abstract

The invention relates to a wafer conveying method and a mechanical arm. The method comprises the following steps: providing a first wafer to the front end of a finger part of a mechanical arm; stretching the mechanical arm to a first length to move the front end of the finger part of the mechanical arm to a first processing position in a first processing chamber; placing the first wafer at the first processing position; the mechanical arm is contracted, so that the front end of the finger part of the mechanical arm is moved out of the first processing chamber; providing a second wafer to the front end of the finger part of the mechanical arm; extending the robotic arm to a second length to move the front end of the finger portion of the robotic arm to a second processing position in the first processing chamber, wherein the second length is different from the first length; and placing the second wafer at the second processing position.

Description

[0001] This invention patent application is a divisional application of the invention patent application entitled "Method and Robotic Arm for Transporting Wafers" with application number 202011643091.2 and application date of December 31, 2020. Technical Field

[0002] This application generally relates to the field of semiconductor manufacturing, and more specifically, to a method and robotic arm for transferring wafers in a semiconductor processing system. Background Technology

[0003] A semiconductor processing system's processing chamber may include one or more processing stations, each capable of processing one wafer. When transferring wafers to a processing chamber containing multiple processing stations, a typical process involves first transferring one or more wafers to a position closer to the chamber's valves, then using a rotating mechanism to transfer these wafers to a position farther from the valves. The next group of one or more wafers is then transferred to a position closer to the valves, and the process continues until all processing stations within the chamber are occupied by wafers. Implementing this transfer method requires a rotating mechanism within the processing chamber, making the equipment structure and operating procedures complex, and the rotation process may also cause wafer damage or contamination.

[0004] Therefore, there is a need for a simpler method for transferring wafers that can avoid rotation within the processing chamber, as well as robotic arms suitable for implementing such methods. Summary of the Invention

[0005] This application provides at least one novel method for transferring wafers and a robotic arm suitable for such a method, which can avoid handling rotational mechanisms within the cavity.

[0006] In one embodiment of this application, a method for transferring a wafer is provided. The method may include: providing a first wafer to the tip of a finger of a robotic arm; extending the robotic arm to a first length to move the tip of the finger of the robotic arm to a first processing position in a first processing chamber; placing the first wafer at the first processing position; retracting the robotic arm to move the tip of the finger of the robotic arm out of the first processing chamber; providing a second wafer to the tip of the finger of the robotic arm; extending the robotic arm to a second length to move the tip of the finger of the robotic arm to a second processing position in the first processing chamber, wherein the second length is different from the first length; and placing the second wafer at the second processing position.

[0007] In some embodiments, the method may include moving the base of the robotic arm near the first processing chamber before extending the robotic arm to the first length.

[0008] In some embodiments, the method may further include: providing a third wafer to the finger tip of the robotic arm; extending the robotic arm to a third length to move the finger tip of the robotic arm to a third processing position in a second processing chamber; and placing the third wafer at the third processing position. In some embodiments, the method may include moving the base of the robotic arm to the vicinity of the second processing chamber before extending the robotic arm to the third length.

[0009] In some embodiments, the method may further include: removing the first wafer and the second wafer from the first processing chamber after the processing of the first wafer and the second wafer is completed. Removing the first wafer from the first processing chamber may include: extending the robotic arm to a first length to move the fingertip of the robotic arm to a first processing position; moving the first wafer from the first processing position to the fingertip of the robotic arm; retracting the robotic arm to remove the first wafer from the first processing chamber; and removing the first wafer from the fingertip of the robotic arm. Removing the second wafer from the first processing chamber may include: extending the robotic arm to a second length to move the fingertip of the robotic arm to a second processing position; moving the second wafer from the second processing position to the fingertip of the robotic arm; retracting the robotic arm to remove the second wafer from the first processing chamber; and removing the second wafer from the fingertip of the robotic arm.

[0010] In some embodiments, the first wafer is placed in the first processing position before the second wafer is placed in the second processing position, and the second wafer is removed from the first processing chamber before the first wafer is removed from the first processing chamber.

[0011] In some embodiments, providing the first wafer to the finger tip of the robotic arm may include moving the first wafer from a first loading lock chamber to the finger tip of the robotic arm, and removing the first wafer from the finger tip of the robotic arm may include moving the first wafer from the finger tip of the robotic arm to a second loading lock chamber.

[0012] In some embodiments, the finger tip of the robotic arm may be a first layer of finger tip of the robotic arm, and the method may further include: after the processing of the first wafer is completed, extending the robotic arm to move the second layer of finger tip of the robotic arm to the first processing position; moving the first wafer from the first processing position to the second layer of finger tip of the robotic arm; retracting the robotic arm to remove the first wafer from the first processing chamber; and removing the first wafer from the second layer of finger tip of the robotic arm.

[0013] In some embodiments, providing the first wafer to the finger tip of the robotic arm may include moving the first wafer from a first-layer loading lock chamber to the first-layer finger tip of the robotic arm, and removing the first wafer from the second-layer finger tip of the robotic arm may include moving the first wafer from the second-layer finger tip of the robotic arm to a second-layer loading lock chamber.

[0014] In some embodiments, the method may include, after retracting the robotic arm to remove the first wafer from the first processing chamber and before removing the first wafer from the tip of the second layer of the robotic arm's fingers, extending the robotic arm to move the tip of the first layer of the robotic arm's fingers to the first processing position and placing a third wafer on the tip of the first layer of the fingers at the first processing position.

[0015] In another embodiment of this application, a method for transferring a wafer is provided. The method may include: providing a first wafer to the tip of a first layer of fingers of a robotic arm; and, during a single opening of a valve in a first processing chamber, performing the following operations: extending the robotic arm to move the tip of a second layer of fingers of the robotic arm to a first processing position in the first processing chamber; moving a second wafer from the first processing position to the tip of the second layer of fingers of the robotic arm; retracting the robotic arm to remove the second wafer from the first processing chamber; extending the robotic arm to move the tip of the first layer of fingers of the robotic arm to a second processing position in the first processing chamber; placing the first wafer at the second processing position; and retracting the robotic arm to remove the tip of the first layer of fingers of the robotic arm from the first processing chamber.

[0016] In some embodiments, the first processing location and the second processing location may be the same processing location.

[0017] In another embodiment of this application, a robotic arm is provided. The robotic arm may include: a first-layer extension unit mounted on a base, comprising a first forearm, a second forearm, a first upper arm, and a second upper arm, wherein a first end of the first forearm and a first end of the second forearm are connected at a first joint, a second end of the first forearm and a first end of the first upper arm are connected at a second joint, a second end of the second forearm and a first end of the second upper arm are connected at a third joint, and a second end of the first upper arm and a second end of the second upper arm are jointly connected to a fulcrum on the base; and a first-layer finger portion mounted at the first joint of the first-layer extension unit.

[0018] In some embodiments, the first upper arm portion and the second upper arm portion are thicker than the first lower arm portion and the second lower arm portion. In some embodiments, the second end of the first upper arm portion and the second end of the second upper arm portion are thicker than the first end of the first upper arm portion and the first end of the second upper arm portion. In some embodiments, the second end of the first lower arm portion and the second end of the second lower arm portion are thicker than the first end of the first lower arm portion and the first end of the second lower arm portion.

[0019] In some embodiments, the first forearm and the second forearm are operable to rotate about the first joint, the first forearm and the first upper arm are operable to rotate about the second joint, the second forearm and the second upper arm are operable to rotate about the third joint, and the first upper arm and the second upper arm are operable to rotate about the fulcrum.

[0020] In some embodiments, the first layer of fingers may include: a front end for carrying a wafer; and a rear end connected between the front end and the first joint.

[0021] In some embodiments, the front end may include a cutout portion. In some embodiments, the front end may include multiple contact points, multiple contact lines, or multiple contact ramps for supporting the wafer from the side of the wafer. In some embodiments, the front end may include a suction cup for adsorbing the wafer from the back of the wafer. The suction cup may be an electrostatic suction cup or a vacuum suction cup.

[0022] In some embodiments, the first layer of fingers may further include: a second layer of extension unit mounted on the base; and a second layer of fingers mounted on the second layer of extension unit. In some embodiments, the first layer of extension unit and the second layer of extension unit are operable to extend independently of each other.

[0023] Details of one or more embodiments of this application are set forth in the following figures and description. Other features, objectives, and advantages will become apparent from the description, figures, and claims. Attached Figure Description

[0024] The following figures are mentioned and included in the disclosure in this specification:

[0025] Figure 1 This illustration shows a structural diagram of a processing chamber comprising multiple processing stations according to some embodiments of this application;

[0026] Figure 2 This application illustrates a schematic diagram of the structure of a semiconductor processing system according to some embodiments.

[0027] Figure 3 This application illustrates a schematic diagram of the structure of a robotic arm according to some embodiments of the present application;

[0028] Figure 4 This illustration shows a structural schematic diagram of another robotic arm according to some embodiments of this application.

[0029] By convention, the various features illustrated in the figures may not be drawn to scale. Therefore, for clarity, the dimensions of various features may be arbitrarily enlarged or reduced. The shapes of the components illustrated are merely exemplary and do not limit the actual shapes of the components. Furthermore, for clarity, the embodiments illustrated may be simplified. Therefore, the figures may not depict all components of a given device or apparatus. Finally, the same reference numerals may be used throughout the specification and figures to denote the same features. Detailed Implementation

[0030] The invention will now be described more fully with reference to the accompanying drawings, and specific exemplary embodiments will be shown by way of illustration. However, the subject matter of this claim can be embodied in many different forms, and therefore the construction of the claimed subject matter is not limited to any of the exemplary embodiments disclosed in this specification; the exemplary embodiments are merely illustrative. Similarly, the present invention aims to provide a reasonably broad scope for the claimed or covered subject matter.

[0031] The terms "in one embodiment" or "according to one embodiment" used in this specification do not necessarily refer to the same specific embodiment, nor do they imply that the claimed technical solution must include all the features described in the embodiment, and the terms "in other (some / some) embodiments" or "according to other (some / some) embodiments" used in this specification do not necessarily refer to different specific embodiments. Their purpose is to, for example, include combinations of all or some of the exemplary embodiments. The terms "comprising" and "including" in this specification are used in an open-ended manner and should therefore be interpreted as meaning "including, but not limited to...". The meaning of "upper" and "lower" as used in this specification is not limited to the relationship directly presented in the drawings; it should include descriptions with explicit corresponding relationships, such as "left" and "right," or the opposite of "upper" and "lower." The term "wafer" in this specification should be understood to be used interchangeably with the terms "substrate," "chip," "wafer," "silicon wafer," etc. This specification uses certain terms to refer to specific system components, and as those skilled in the art will understand, different companies may use different names to refer to these system components.

[0032] Figure 1 A schematic diagram of the processing chamber 100, comprising multiple processing stations 101, 102, 103, and 104, is shown. Although Figure 1 A specific number of processing stations are shown, and those skilled in the art will understand that processing chamber 100 may include fewer or more processing stations.

[0033] like Figure 1 As shown, the processing chamber 100 has a valve 105. The processing chamber 100 can be connected to an adjacent chamber (e.g., a transfer chamber) via the valve 105. When the valve 105 is open, a robotic arm in the adjacent chamber can transfer a wafer to be processed into the processing chamber 100 via the valve 105, or transfer a processed wafer out of the processing chamber 100 via the valve 105. Figure 1 In the exemplary arrangement shown, robotic arms in adjacent chambers can simultaneously transfer two wafers into or out of processing chamber 100. In other embodiments, robotic arms in adjacent chambers can transfer only one wafer at a time or transfer more wafers simultaneously.

[0034] The following is combined with Figure 1 The processing chamber 100 shown illustrates a method for transferring wafers using a rotation mechanism within the processing chamber. Similar methods can be implemented for processing chambers with other arrangements.

[0035] When valve 105 is opened, robotic arms in adjacent chambers simultaneously transfer two wafers to processing stations 101 and 102, which are closer to valve 105. Then, a rotating mechanism is used to transfer the wafers from processing stations 101 and 102 to positions farther from the valve in the processing chamber. For example, processing stations 101, 102, 103, and 104 can be rotated around the center of the processing chamber, thereby rotating processing stations 101 and 102, along with their wafers, to their original positions in processing stations 103 and 104; alternatively, the positions of processing stations 101, 102, 103, and 104 remain unchanged, and a wafer rotating device in processing chamber 100 moves the wafers from processing stations 101 and 102 to processing stations 103 and 104. After rotation, the two processing stations closest to valve 105 will no longer contain wafers (for example, in the case of rotating processing stations, these two stations are processing stations 103 and 104; in the case of rotating wafers, these two stations are still processing stations 101 and 102). The robotic arms in adjacent chambers can then simultaneously transfer two more wafers to the two processing stations closest to valve 105. Between the two transfers by the robotic arms, depending on the specific process steps, valve 105 can remain open or be closed first and then opened. After wafers have been placed in processing stations 101, 102, 103, and 104, valve 105 can be closed, and semiconductor processing processes, such as deposition, etching, and cleaning, can be performed on the wafers in processing stations 101, 102, 103, and 104. After the wafer processing is completed, a similar rotation mechanism is used when the robotic arms in adjacent chambers remove the wafers from processing chamber 100.

[0036] Implementing the above-described transfer method requires a rotating mechanism (e.g., rotating the processing station or rotating the wafer) to be installed in the processing chamber 100, which makes the equipment structure and operating procedures more complex, and may also cause wafer damage or contamination during the rotation process.

[0037] Figure 2 A schematic diagram of a semiconductor processing system 200 according to some embodiments of this application is shown. The semiconductor processing system 200 includes a processing chamber 210, a processing chamber 220, a processing chamber 230, a transfer chamber 240, and a loading lock chamber 250. The transfer chamber 240 is connected to the processing chambers 210, 220, 230, and 250 via valves 205, 215, 225, and 235, respectively. Each processing chamber contains four processing stations. Processing chamber 210 includes processing stations 201, 202, 203, and 204. Processing chamber 220 includes processing stations 211, 212, 213, and 214. Processing chamber 230 includes processing stations 221, 222, 223, and 224. Although... Figure 2The diagram illustrates a specific number of processing chambers and processing stations. Those skilled in the art will understand that the semiconductor processing system 200 may include fewer or more processing chambers and / or processing stations, and each processing chamber may also include a different number of processing stations. The processing processes performed in each processing chamber may be the same or different. The processing system 200 may also have other arrangements of chambers and stations.

[0038] A robotic arm 260 is mounted in transfer chamber 240. The robotic arm 260 includes two finger tips 261, each capable of carrying one wafer, thus allowing the robotic arm 260 to carry two wafers simultaneously. In other embodiments, the robotic arm 260 may include fewer or more finger tips 261. The robotic arm 260 is telescopic, allowing the finger tips 261 to enter either processing chamber or loading lock chamber 250. In some embodiments, the robotic arm 260 may be mounted on a fixed base (i.e., a non-movable base). In other embodiments, the robotic arm 260 may be mounted on a movable base (e.g., a base mounted on a slide rail), so that the base of the robotic arm 260 can be moved to the vicinity of the corresponding chamber when wafers need to be transferred to or removed from a chamber.

[0039] The following is combined with Figure 2 The semiconductor processing system 200 shown is used to describe a method for transferring wafers according to embodiments of this application that avoids rotation within the processing chamber. Similar methods can be implemented for other chamber and station arrangements. Unless necessary, the specific timing of the opening of valves 205, 215, 225, and 235 will not be detailed here. Those skilled in the art will know when to open the respective valves to allow the finger tip 261 of the robotic arm 260 to enter the corresponding chamber.

[0040] According to some embodiments of this application, firstly, a wafer can be provided to the finger tip 261 of a robotic arm 260. For example, the finger tip 261 of the robotic arm 260 can remove the wafer from the loading lock chamber 250 (i.e., move the wafer from the loading lock chamber 250 to the finger tip 261 of the robotic arm 260) or remove the wafer from another processing chamber where a previous process was performed. Then, the robotic arm 260 can be extended to allow the finger tip 261 to enter the processing chamber 210 to reach the processing stations 203, 204, and place the wafer on the finger tip 261 into the processing stations 203, 204. Next, the robotic arm 260 can be retracted to remove the finger tip 261 from the processing chamber 210. The tip of the finger 261 can again retrieve the wafer from the loading lock chamber 250. The robotic arm 260 extends to allow the tip of the finger 261 to enter the processing chamber 210 and reach the processing stations 201 and 202, where the wafer on the tip of the finger 261 is placed. Because the distance between the processing stations 203 and 204 and the valve 205 is greater than the distance between the processing stations 201 and 202 and the valve 205, the extension length of the robotic arm 260 when placing the wafer at the processing stations 203 and 204 is greater than the extension length of the robotic arm 260 when placing the wafer at the processing stations 201 and 202.

[0041] Wafers can be placed in processing stations 211, 212, 213, 214 of processing chamber 220 and processing stations 221, 222, 223, 224 of processing chamber 230 in the same manner.

[0042] After the wafer processing in the processing chamber 210 is completed, the robotic arm 260 can remove the wafer from the processing chamber 210 in the following manner.

[0043] First, the robotic arm 260 extends to move the finger tip 261 to processing stations 201 and 202, picking up wafers from processing stations 201 and 202 (i.e., moving wafers from processing stations 201 and 202 to the finger tip 261). Then, the robotic arm 260 retracts to remove the finger tip 261, along with the wafer, from processing chamber 210. Next, the wafer can be removed from the finger tip 261, for example, by transferring the wafer to loading lock chamber 250 or another processing chamber for the next process. Then, the robotic arm 260 can extend to move the finger tip 261 to processing stations 203 and 204, picking up wafers from processing stations 203 and 204, and then retracts the robotic arm 260 to remove the finger tip 261, along with the wafer, from processing chamber 210, and then remove the wafer from the finger tip 261.

[0044] Wafers can be removed from processing stations 211, 212, 213, 214 of processing chamber 220 and processing stations 221, 222, 223, 224 of processing chamber 230 in the same manner.

[0045] In the above example, during the transfer of wafers to the processing chamber, the wafers are first placed in processing stations farther from the chamber valve (e.g., processing stations 203, 204), and then placed in processing stations closer to the chamber valve (e.g., processing stations 201, 202). Conversely, during the removal of wafers from the processing chamber, the wafers in the processing stations closer to the chamber valve (e.g., processing stations 201, 202) are removed first, followed by the wafers in the processing stations farther from the chamber valve (e.g., processing stations 203, 204). This placement and removal sequence prevents contamination caused by the fingertips 261 or other parts of the robotic arm 260 passing over the wafers placed in the processing stations. In other embodiments, different placement and / or removal sequences may also be used.

[0046] In some embodiments, the loading lock chamber 250 may have a double-layer structure. In other words, the loading lock chamber 250 may include an upper loading lock chamber and a lower loading lock chamber. A robotic arm 260 may be configured to remove the wafer to be processed from the first loading lock chamber (e.g., the lower loading lock chamber) and transfer it to the processing chamber for processing, while the processed wafer removed from the processing chamber is placed in the second loading lock chamber (e.g., the upper loading lock chamber). This avoids cross-contamination between the wafer to be processed and the processed wafer.

[0047] In some embodiments, the robotic arm 260 may have a dual-layer structure. In other words, the robotic arm 260 includes an upper robotic arm and a lower robotic arm, wherein the upper robotic arm includes an upper finger tip, and the lower robotic arm includes a lower finger tip. The robotic arm 260 may be configured to use the first layer finger tip (e.g., the upper finger tip) to transport the wafer to be processed to the processing chamber for processing, and use the second layer finger tip (e.g., the lower finger tip) to retrieve the processed wafer from the processing chamber. This avoids cross-contamination between the wafer to be processed and the processed wafer. When using dual-layer loading lock chambers simultaneously, the robotic arm 260 may be configured to use the first layer finger tip (e.g., the upper finger tip) to retrieve the wafer to be processed from the first layer loading lock chamber (e.g., the upper loading lock chamber) and transport it to the processing chamber for processing, while using the second layer finger tip (e.g., the lower finger tip) to retrieve the processed wafer from the processing chamber and place it into the second layer loading lock chamber (e.g., the lower loading lock chamber). The finger tips of each layer and the loading lock chambers of each layer can be combined in different ways to implement wafer transfer.

[0048] In an embodiment where the robotic arm 260 has a double-layer structure, the robotic arm 260 can perform two operations—removing a processed wafer and placing a wafer to be processed—during a single opening of the valve in the processing chamber. For example, the wafer to be processed can be provided to the tip of the first layer of fingers of the robotic arm 260 (e.g., the tip of the upper finger). Then, during a single opening of the valve 205, the following operations are performed: the robotic arm 260 is extended so that the tip of the second layer of fingers of the robotic arm 260 (e.g., the tip of the lower finger) moves to processing stations 201 and 202, the tip of the second layer of fingers of the robotic arm 260 picks up the processed wafer from processing stations 201 and 202, and the robotic arm 260 is retracted so that the tip of the second layer of fingers, along with the processed wafer, is removed from the processing chamber 210; then the robotic arm 260 is extended so that the tip of the first layer of fingers of the robotic arm 260 moves to processing stations 201 and 202, and the wafer to be processed is placed in processing stations 201 and 202, and the robotic arm 260 is retracted so that the tip of the first layer of fingers is removed from the processing chamber 260. After completing the operations of retrieving the processed wafer and placing the wafer to be processed, the processed wafer is removed from the tip of the second layer of fingers of the robotic arm 260. In some embodiments, the processing station at which the second layer of the robotic arm 260 retrieves the processed wafer may be different from the processing station at which the wafer to be processed is placed.

[0049] Figure 3 A schematic diagram of the structure of a robotic arm 300 according to some embodiments of this application is shown. For example... Figure 3 As shown, the robotic arm 300 includes a base 301, an extension unit 302, and a finger portion 303. The extension unit 302 is mounted on the base 301 at a fulcrum 307, and the finger portion 303 is mounted on the extension unit 302 at a joint 308.

[0050] The extension unit 302 includes a forearm portion 304 and a large arm portion 305. One end of the forearm portion 304 is connected to a joint 308, and the other end of the forearm portion 304 is connected to one end of the large arm portion 305 at a joint 306. The other end of the large arm portion 305 is connected to a fulcrum 307. The forearm portion 304 is rotatable about the joint 308. The forearm portion 304 and the large arm portion 305 are rotatable about the joint 306, and the large arm portion 305 is rotatable about the fulcrum 307. Through the rotation of the forearm portion 304 and the large arm portion 305 about the joints 308, 306, and the fulcrum 307, the extension unit 302 enables the extension and retraction of the robotic arm 300. In other embodiments, the extension unit of the robotic arm can achieve extension and retraction using an elastically deformable element (e.g., a spring mechanism).

[0051] The finger portion 303 may include a front end 309 and a rear end 310. The front end 309 may include structures for carrying the wafer, such as blades, paddles, forks, or clamps. The rear end 310 is connected between the front end 309 and the joint 308. This is for illustrative purposes only. Figure 3 The front end 309 of the given finger portion 303 can support two wafers. It should be understood that the front end 309 of the finger portion 303 can also support only one wafer or support more wafers.

[0052] Since the front end 309 directly contacts the wafer, it can be made of materials such as ceramics, which are less likely to cause contamination from particles or impurities when in contact with the wafer. The other parts of the robotic arm 300 can be made of metal.

[0053] In some embodiments, the robotic arm 300 can be used to implement the foregoing. Figure 2 The described method involves transferring wafers in a way that avoids rotation within the processing chamber. In implementing this method, the robotic arm needs to extend sufficiently to allow its fingertips to reach the distal end of the processing chamber (e.g., processing stations 203, 204 of processing chamber 210). For example, the extended length of the robotic arm needs to be at least 1250 mm, and in some applications, it needs to reach 1285 mm or 1360 mm. However, extending the robotic arm 300 to a longer length can cause problems such as wafer transfer jitter. Therefore, a stabilization mechanism is needed to enhance the stability of the robotic arm.

[0054] Figure 4 A schematic diagram of a robotic arm 400 according to some embodiments of this application is shown. The robotic arm 400 may have enhanced stability.

[0055] like Figure 4 As shown, the robotic arm 400 includes a base 401, an extension unit, and fingers. The extension unit is mounted on the base 401 at a fulcrum 402, and the fingers are mounted on the extension unit at joints 403.

[0056] The extension unit includes a first forearm 404, a second forearm 405, a first upper arm 406, and a second upper arm 407. The first end of the first forearm 404 is connected to the first end of the second forearm 405 at joint 403. The second end of the first forearm 404 is connected to the first end of the first upper arm 406 at joint 408. The second end of the second forearm 405 is connected to the first end of the second upper arm 407 at joint 409. The second ends of the first upper arm 406 and the second upper arm 407 are connected together at fulcrum 402. Compared to the robotic arm 300, the extension unit of the robotic arm 400 adds a set of upper arm and forearm sections, thus providing more stable support for the fingers. Reinforcing ribs may also be added below one or more of the first forearm 404, second forearm 405, first upper arm 406, and second upper arm 407.

[0057] The first forearm 404 and the second forearm 406 can rotate around joint 403; the first forearm 404 and the first upper arm 406 can rotate around joint 408; the second forearm 405 and the second upper arm 407 can rotate around joint 409; and the first upper arm 406 and the second upper arm can rotate around fulcrum 402. Through the rotation of the first forearm 404, the second forearm 405, the first upper arm 406, and the second upper arm 407 around joints 403, 408, 409, and fulcrum 402, the extension unit enables the extension and retraction of the robotic arm 400.

[0058] In some embodiments, the first large arm 406 and the second large arm 407 are thicker than the first small arm 404 and the second small arm 405. In some embodiments, the second end of the first large arm 406 and the second end of the second large arm 407 are thicker than the first end of the first large arm 406 and the first end of the second large arm 407. In some embodiments, the second end of the first small arm 404 and the second end of the second small arm 405 are thicker than the first end of the first small arm 404 and the first end of the second small arm 405. That is, in the direction from the fulcrum 402 to the finger, each segment of the arm can gradually taper from thick to thin, thereby reducing the jitter of the robotic arm 400 when transporting wafers.

[0059] The finger portion includes a front end 410 and a rear end 411. The front end 410 may include structures for carrying the wafer, such as blades, paddles, forks, or clamps. The rear end 411 connects the front end 410 and the joint 403. This is for illustrative purposes only. Figure 4 The given finger tip 410 can support two wafers, but it should be understood that the finger tip 410 can also support only one wafer or support more wafers.

[0060] In some embodiments, the front end 410 may include a cutout portion, for example... Figure 4The hole 412 shown is used to reduce the weight of the front end 410.

[0061] In some embodiments, to more stably support the wafer, the front end 410 may include multiple contact points, multiple contact lines, or multiple contact ramps for supporting the wafer from the side of the wafer. In some embodiments, the number of contact points is not less than four. In some embodiments, the front end 410 may include a chuck for adsorbing the wafer from the back of the wafer, such as an electrostatic chuck or a vacuum chuck.

[0062] Since the front end 410 will directly contact the wafer, materials such as ceramics, which are less likely to cause particle or impurity contamination when in contact with the wafer, can be used. Other parts of the robotic arm 400 can be made of metal.

[0063] In some embodiments, the robotic arm 400 may have a dual-layer structure, that is, in addition to the extension unit and fingers described above, the robotic arm 400 may also include a second extension unit mounted on a base 401 and a second layer of fingers mounted on the second extension unit. The second extension unit and the second layer of fingers may have a structure similar to the extension unit and fingers described above. In some embodiments, both extension units are mounted at a fulcrum 402. In some embodiments, the two extension units may extend independently of each other, so that the two layers of fingers can be used respectively to remove processed wafers from the processing chamber and place wafers to be processed into the processing chamber, to avoid cross-contamination between the wafers to be processed and the processed wafers.

[0064] This application provides, on the one hand, a method for transferring wafers that avoids rotation within the processing chamber, and on the other hand, a robotic arm with enhanced stability that can more effectively implement the aforementioned method.

[0065] The description in this specification is provided to enable those skilled in the art to make or use the invention. Various modifications to the invention will readily apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of the invention. Therefore, the invention is not limited to the examples and designs described herein, but is given the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of transferring wafers, comprising: providing a first wafer to a finger tip end of a robot; extending the robot to a first length to move the finger tip end of the robot to a first processing position in a first processing chamber; placing the first wafer in the first processing position; retracting the robot to move the finger tip end of the robot out of the first processing chamber; providing a second wafer to the finger tip end of the robot; extending the robot to a second length to move the finger tip end of the robot to a second processing position in the first processing chamber, wherein the second length is different than the first length; and placing the second wafer in the second processing position.

2. The method of claim 1, comprising: moving a base of the robot to be near the first processing chamber prior to extending the robot to the first length.

3. The method of claim 1, further comprising: providing a third wafer to the finger tip end of the robot; extending the robot to a third length to move the finger tip end of the robot to a third processing position in a second processing chamber; and placing the third wafer in the third processing position.

4. The method of claim 3, comprising: moving a base of the robot to be near the second processing chamber prior to extending the robot to the third length.

5. The method of claim 1, further comprising: removing the first wafer and the second wafer from the first processing chamber after a processing procedure of the first wafer and the second wafer is completed; wherein removing the first wafer from the first processing chamber comprises: extending the robot to the first length to move the finger tip end of the robot to the first processing position; moving the first wafer from the first processing position to the finger tip end of the robot; retracting the robot to move the first wafer out of the first processing chamber; and removing the first wafer from the finger tip end of the robot; and wherein removing the second wafer from the first processing chamber comprises: extending the robot to the second length to move the finger tip end of the robot to the second processing position; moving the second wafer from the second processing position to the finger tip end of the robot; retracting the robot to move the second wafer out of the first processing chamber; and removing the second wafer from the finger tip end of the robot.

6. The method of claim 5, wherein the first wafer is placed in the first processing position prior to placing the second wafer in the second processing position, and the second wafer is removed from the first processing chamber prior to removing the first wafer from the first processing chamber.

7. The method of claim 5, wherein providing the first wafer to the finger tip end of the robot includes moving the first wafer from a first tier load lock chamber to the finger tip end of the robot, removing the first wafer from the finger tip end of the robot includes moving the first wafer from the finger tip end of the robot to a second tier load lock chamber.

8. The method of claim 1, wherein the finger tip end of the robot is a first tier finger tip end of the robot, the method further comprising: after a processing process of the first wafer is completed, extending the robot to move a second tier finger tip end of the robot to the first processing position; moving the first wafer from the first processing position to the second tier finger tip end of the robot; contracting the robot to move the first wafer out of the first processing chamber; and removing the first wafer from the second tier finger tip end of the robot.

9. The method of claim 8, wherein providing the first wafer to the finger tip end of the robot includes moving the first wafer from a first tier load lock chamber to the first tier finger tip end of the robot, removing the first wafer from the second tier finger tip end of the robot includes moving the first wafer from the second tier finger tip end of the robot to a second tier load lock chamber.

10. The method of claim 8, comprising after contracting the robot to move the first wafer out of the first processing chamber and before removing the first wafer from the second tier finger tip end of the robot, extending the robot to move the first tier finger tip end of the robot to the first processing position and placing a third wafer on the first tier finger tip end at the first processing position.

11. A method of transferring wafers, comprising: providing a first wafer to a first tier finger tip end of a robot; and during one opening of a valve of a first processing chamber: extending the robot to move a second tier finger tip end of the robot to a first processing position in the first processing chamber; moving a second wafer in the first processing position to the second tier finger tip end of the robot; contracting the robot to move the second wafer out of the first processing chamber; extending the robot to move the first tier finger tip end of the robot to a second processing position in the first processing chamber; placing the first wafer at the second processing position; and contracting the robot to move the first tier finger tip end of the robot out of the first processing chamber.

12. The method of claim 11, wherein the first processing position and the second processing position are the same processing position.

13. A robot, comprising: ​ ​ a first layer of extension units mounted on a base, the first layer of extension units including a first forearm, a second forearm, a first upper arm, and a second upper arm, wherein a first end of the first forearm and a first end of the second forearm are connected at a first joint, a second end of the first forearm and a first end of the first upper arm are connected at a second joint, a second end of the second forearm and a first end of the second upper arm are connected at a third joint, and a second end of the first upper arm and a second end of the second upper arm are connected together at a fulcrum on the base; and a first layer of finger units mounted at the first joint of the first layer of extension units.

14. The robotic arm of claim 13, wherein the first upper arm and the second upper arm are thicker than the first forearm and the second forearm.

15. The robotic arm of claim 13, wherein the second end of the first upper arm and the second end of the second upper arm are thicker than the first end of the first upper arm and the first end of the second upper arm.

16. The robotic arm of claim 13, wherein the second end of the first forearm and the second end of the second forearm are thicker than the first end of the first forearm and the first end of the second forearm.

17. The robotic arm of claim 13, wherein the first forearm and the second forearm are operable to rotate about the first joint, the first forearm and the first upper arm are operable to rotate about the second joint, the second forearm and the second upper arm are operable to rotate about the third joint, and the first upper arm and the second upper arm are operable to rotate about the fulcrum.

18. The robotic arm of claim 13, wherein the first layer of finger units includes: a front end for carrying a wafer; and a back end connected between the front end and the first joint.

19. The robotic arm of claim 18, wherein the front end includes a hollowed-out portion.

20. The robotic arm of claim 18, wherein the front end includes a plurality of contact points, a plurality of contact lines, or a plurality of contact bevels for supporting the wafer from a side of the wafer.

21. The robotic arm of claim 18, wherein the front end includes a suction cup for suctioning the wafer from a back of the wafer.

22. The robotic arm of claim 21, wherein the suction cup includes an electrostatic force suction cup or a vacuum suction cup.

23. The robotic arm of claim 13, further comprising: a second layer of extension units mounted on the base; and a second layer of finger units mounted on the second layer of extension units.

24. The robotic arm of claim 23, wherein the first layer of extension units and the second layer of extension units are operable to be independently extended relative to each other. ​

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