Workpiece handling architecture for high workpiece throughput

Abstract

A system for transferring semiconductor workpieces from a load lock to an alignment station and onto a platen is disclosed. The system comprises two load locks, two robots, and one alignment station. Each robot is associated with its respective load lock and follows a fixed sequence. The robot returns the processed workpiece to the load lock and removes the unprocessed workpiece. The robot then moves to the alignment station, where it removes the aligned workpiece from the alignment station and places the unprocessed workpiece onto the alignment station. Next, the robot moves to the platen, where it removes the processed workpiece and places the aligned workpiece. The robot then returns to the load lock and repeats this sequence.

Description

Technical Field

[0001] This application claims priority to U.S. Patent Application No. 17 / 977,417, filed Oct. 31, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] Embodiments relate to systems for achieving high workpiece throughput, and more particularly, higher throughput for semiconductor workpieces when they are being processed.

Background Art

[0003] Ions are used in a plurality of semiconductor processes, such as implantation, amorphization, deposition, and etching processes. These semiconductor processes are generally performed in a process chamber maintained in a near-vacuum state.

[0004] Before a semiconductor workpiece can be processed, the semiconductor workpiece is transported from the ambient environment to the process chamber. Further, after being transported to the process chamber, the semiconductor workpiece is generally aligned in a particular orientation.

[0005] To achieve this sequence, one or more load locks are used to transfer workpieces into and out of the process chamber. Additionally, an orientation station is generally used to align the workpiece in a desired orientation. After these two processes are completed, the workpiece can then be mounted on a platen for processing.

[0006] Often, the transfer of workpieces from the load lock to the orientation station and onto the platen can become a bottleneck in semiconductor processes. For example, processing a workpiece on the platen can be done in less than 5 seconds, which ideally would allow for the processing of at least 720 workpieces per hour. However, conventional transport systems are limited to a throughput of approximately 500 workpieces per hour.

[0007] Therefore, a system that transports the workpiece between the load lock and the platen would be beneficial, as it would ensure that semiconductor processing becomes the bottleneck in the process. [Overview of the project]

[0008] A system for transferring semiconductor workpieces from a load lock to an alignment station and onto a platen is disclosed. The system comprises two load locks, two robots, and one alignment station. Each robot is associated with its respective load lock and follows a fixed sequence. The robot returns the processed workpiece to the load lock and removes the unprocessed workpiece. The robot then moves to the alignment station, where it removes the aligned workpiece from the alignment station and places the unprocessed workpiece onto the alignment station. Next, the robot moves to the platen, where it removes the processed workpiece and places the aligned workpiece. The robot then returns to the load lock and repeats this sequence.

[0009] According to one embodiment, a system for transporting workpieces to a platen is disclosed. The system comprises two load locks, two robots, each having two arms associated with the respective load lock and each capable of independently retracting and extending, and an orientation station for aligning each workpiece before it is placed on the platen. In some embodiments, each robot iteratively performs a sequence comprising: moving to the respective load lock, using a first arm of the two arms to place a processed workpiece in the respective load lock and using a second arm of the two arms to remove an unprocessed workpiece; moving to the orientation station, using the first arm to remove an aligned workpiece from the orientation station and using the second arm to place an unprocessed workpiece on the orientation station; moving to the platen, using the second arm to remove a processed workpiece from the platen and using the first arm to place an aligned workpiece on the platen.

[0010] In some embodiments, the second robot of two robots performs a sequence that is delayed compared to the sequence performed by the first robot of two robots. In some embodiments, the first robot of two robots takes an unprocessed workpiece from the first load lock of two load locks and places the unprocessed workpiece on an alignment station, and the second robot of two robots takes the unprocessed workpiece from the alignment station after alignment. In some embodiments, the first robot of two robots takes an aligned workpiece from the alignment station and places the aligned workpiece on a platen, and the second robot of two robots takes the aligned workpiece from the platen after processing. In some embodiments, the two load locks each have a stacked configuration with two independent chambers. In some embodiments, each independent chamber holds two or three workpieces. In some embodiments, the two arms of each robot are fixed in the yaw direction. In some embodiments, the system further comprises a plurality of forward-opening unified pods (FOUPs) and an atmospheric robot positioned in the ambient environment, the atmospheric robot transferring workpieces between two load locks and the FOUPs. In some embodiments, the atmospheric robot has a 1+N pick arrangement, allowing the atmospheric robot to transfer one, N, or N+1 workpieces at a time between the FOUPs and the two load locks.

[0011] In another embodiment, a method for transferring a workpiece between a plurality of load locks and a platen is disclosed. The method comprises performing a sequence of processes, the sequence comprising: placing a processed workpiece in one of the plurality of load locks and removing an unprocessed workpiece; removing an aligned workpiece from an alignment station and placing an unprocessed workpiece on the alignment station; and removing a processed workpiece from a platen and placing an aligned workpiece on the platen. In some embodiments, the sequence is repeated multiple times. In some embodiments, the sequence is performed by a first robot. In some embodiments, the sequence is also performed by a second robot and is delayed compared to the sequence performed by the first robot. In some embodiments, the first robot removes an unprocessed workpiece from a first load lock of the plurality of load locks and places an unprocessed workpiece on an alignment station, and the second robot removes an unprocessed workpiece from the alignment station after alignment. In some embodiments, a second robot retrieves an aligned workpiece from an orientation station and places it on a platen, while a first robot retrieves the aligned workpiece from the platen after processing. In some embodiments, a first robot transfers a workpiece to and from a first load lock among a plurality of load locks, and a second robot transfers a workpiece to and from a second load lock among a plurality of load locks. In some embodiments, the plurality of load locks have a stacked configuration, each having two independent chambers.

[0012] For a better understanding of this disclosure, references are made to the accompanying drawings incorporated herein by reference. [Brief explanation of the drawing]

[0013] [Figure 1]This figure shows a system for transporting workpieces according to one embodiment. [Figure 2] This figure shows a load lock according to one embodiment. [Figure 3] This is a side view of a multi-pick robot according to one embodiment. [Figure 4] This is a flowchart showing the sequence of actions performed by one of the robots. [Figure 5] This flowchart shows the sequence of actions for processing the workpiece and returning it to the load lock. [Modes for carrying out the invention]

[0014] Figure 1 shows one embodiment of a system for transporting workpieces. The system includes a plurality of FOUPs 100 (forward-opening unified pods). An EFEM 101 (equipment front-end module) includes an atmospheric robot 110 used to pick up and replace workpieces from the FOUPs 100. The atmospheric robot 110 may have a 2+1 pick arrangement to allow the atmospheric robot 110 to transport one, two, or three workpieces per exchange. In other words, the atmospheric robot 110 has two independently controllable arms, also called dual yaws. In this embodiment, one of the arms has two picks that move together, and the second arm has one pick. In another embodiment, the atmospheric robot 110 may have a 1+1 pick arrangement to allow the atmospheric robot 110 to transport one or two workpieces per exchange. In yet another embodiment, the atmospheric robot 110 may have a 1+N pick arrangement, where N is 1 or greater.

[0015] The atmospheric robot 110 is used to move workpieces between the FOUP 100 and load locks 120a and 120b. In this figure, there are two load locks, namely the first load lock 120a and the second load lock 120b. Generally, assuming that the atmospheric robot 110 has a 1+N pick arrangement, the atmospheric robot 110 is capable of transporting N+1, N, or 1 workpiece at a time.

[0016] Load locks 120a and 120b are used to isolate the process chamber 10 from the surrounding environment 20.

[0017] In one embodiment shown in Figure 2, the load locks 120a and 120b may each be in a stacked configuration. This allows each load lock 120a and 120b to comprise two independently controllable chambers 121a and 121b. Thus, the first chamber 121a of the first load lock 120a may be opened to the process chamber 10, while the second chamber 121b may or may not be opened to the process chamber 10. In this way, one chamber can supply unprocessed workpieces to the process chamber 10, and the second chamber can return processed workpieces to the ambient environment 20.

[0018] Each chamber of the load lock may be capable of holding several workpieces. In one embodiment, each chamber may hold two workpieces. In another embodiment, each chamber may hold three workpieces. Of course, a chamber may hold more workpieces if desired.

[0019] Two robots 130a and 130b are arranged in the process chamber 10. The two robots 130a and 130b may be SCARA (Selective Compliance Articulated Robot Arm) type robots capable of moving in the height direction, radial direction, and rotating in the yaw direction. In one embodiment, robots 130a and 130b each have two arms fixed in the yaw direction. These arms can be extended and retracted independently. This allows the arms to rotate in sync and move in the height direction, but to move independently in the radial direction. Figure 3 shows a side view of the first robot 130a, showing the first arm 131a retracted and the second arm 131b extended. In another embodiment, robots 130a and 130b have two arms that can move independently on several axes. In this embodiment, software may be used such that the arms are fixed in the yaw direction. In all embodiments, the robot has two arms that can be extended and retracted independently.

[0020] An alignment station 140 is also installed in the process chamber 10. The alignment station is used to align a workpiece to a specific orientation. Workpieces generally have notches positioned along their edges that identify the orientation of the workpiece. The alignment station 140 is used to rotate the workpiece until the notches are in predetermined positions. In this system, the alignment station 140 can align only one workpiece at a time. The alignment station 140 uses an alignment mechanism to orient the workpiece. For example, the alignment mechanism may include a sensor used to detect notches in the workpiece. In some embodiments, the sensor may be a camera. In another embodiment, a light source may be installed on one side of the workpiece. The light source may be directed towards the edge of the workpiece, and a sensor positioned on the opposite side of the workpiece is used to detect the presence of the notches. The position of the notches is determined based on the increase in light received by the sensor. Of course, other alignment mechanisms may be used.

[0021] The orientation station 140 is positioned so that both the first robot 130a and the second robot 130b can access the orientation station 140.

[0022] A platen 150 is located beyond the orientation station 140. The workpiece is placed on the platen 150 so that it can be processed. For example, while on the platen 150, the workpiece may undergo ion implantation, etching, or some other process. In some embodiments, the platen may be an electrostatic chuck. Similarly, the platen is positioned so that both the first robot 130a and the second robot 130b can access it.

[0023] The structure of the system has been described. Next, the operations of each robot will be explained. Since each robot has two arms, each robot can handle two workpieces at each station. Figure 4 shows the operation of one of the robots.

[0024] First, as shown in box 300 of Figure 4, the first robot 130a uses the first arm 131a to take out an unprocessed workpiece from the first load lock 120a, and also uses the second arm 131b to place the processed workpiece into the first load lock 120a.

[0025] Next, as shown in box 310, the first robot 130a moves so that the first robot 130a can access the orientation station 140. When it reaches the orientation station 140, as shown in box 320, the first robot 130a uses the second arm 131b to take out the aligned workpiece from the orientation station 140. The first robot 130a then uses the first arm 131a to place the unprocessed workpiece onto the orientation station.

[0026] The first robot 130a then moves to the platen 150, as shown in box 330. At the platen 150, as shown in box 340, the first robot 130a uses the first arm 131a to take out the processed workpiece from the platen 150. The first robot 130a then uses the second arm 131b to place the aligned workpiece onto the platen.

[0027] The first robot 130a then moves to the load lock 120a, as shown in box 350. Then, this sequence is repeated.

[0028] Note that the second robot 130b also performs the same sequence as shown in Figure 4, but performs it later than the first robot 130a. In this way, the two robots 130a and 130b cooperate to move the workpiece to and from the load lock.

[0029] Figure 5 shows a detailed flowchart illustrating the sequence of operations performed by the two robots 130a and 130b. In this example, workpieces already in the process are labeled with letters, while workpieces entering the process chamber during this sequence are labeled with numbers.

[0030] When this sequence begins, several workpieces are already in the process chamber 10. These include workpiece A, which is being grasped / located by one of the arms of the first robot 130a; workpiece B, which is on the platen 150; workpiece C, which is being transported from the orientation station 140 to the platen 150; and workpiece D, which is on the orientation station 140. Thus, the first few processes shown in Figure 5 include both workpieces already in the process, as well as new workpieces.

[0031] As shown in box 500, the first robot 130a uses one of its arms to place the processed workpiece A into the load lock 120a and uses the other arm to remove the unprocessed workpiece 1.

[0032] Almost simultaneously, as shown in box 505, the second robot 130b removes the processed workpiece B from the platen 150 and places the aligned workpiece C on the platen 150.

[0033] Next, as shown in box 510, the first robot 130a takes the aligned workpiece D from the orientation station 140 and places the unprocessed workpiece 1 on the orientation station 140.

[0034] Almost simultaneously, as shown in box 515, the second robot 130b uses one of its arms to place the processed workpiece B into the load lock 120b and uses the other arm to remove the unprocessed workpiece 2.

[0035] Next, as shown in box 520, the first robot 130a removes the processed workpiece C from the platen 150 and places the aligned workpiece D on the platen 150.

[0036] Almost simultaneously, as shown in box 525, the second robot 130b removes the aligned workpiece 1 from the orientation station 140 and places the unprocessed workpiece 2 on the orientation station 140.

[0037] As shown in box 530, the first robot 130a uses one of its arms to place the processed workpiece C into the load lock 120a and uses the other arm to remove the unprocessed workpiece 3.

[0038] Almost simultaneously, as shown in box 535, the second robot 130b removes the processed workpiece D from the platen 150 and places the aligned workpiece 1 on the platen 150.

[0039] Next, as shown in box 540, the first robot 130a takes the aligned workpiece 2 from the orientation station 140 and places the unprocessed workpiece 3 on the orientation station 140.

[0040] Almost simultaneously, as shown in box 545, the second robot 130b uses one of its arms to place the processed workpiece D into the load lock 120b and uses the other arm to remove the unprocessed workpiece 4.

[0041] Next, as shown in box 550, the first robot 130a removes the processed workpiece 1 from the platen 150 and places the aligned workpiece 2 on the platen 150.

[0042] Almost simultaneously, as shown in box 555, the second robot 130b removes the aligned workpiece 3 from the orientation station 140 and places the unprocessed workpiece 4 on the orientation station 140.

[0043] As shown in box 560, the first robot 130a uses one of its arms to place the processed workpiece 1 into the load lock 120a and uses the other arm to remove the unprocessed workpiece 5.

[0044] Almost simultaneously, as shown in box 565, the second robot 130b removes the processed workpiece 2 from the platen 150 and places the aligned workpiece 3 on the platen 150.

[0045] It should be noted that boxes 500, 510, 525, 535, 550, and 560 describe the sequence of operations that workpiece 1 undergoes. Thus, in this embodiment, the workpiece removed from the load lock 120a by the first robot 130a is placed on the orientation station 140 by the first robot 130a. The workpiece is then removed from the orientation station 140 by the second robot 130b and placed on the platen 150. Finally, the workpiece is then removed by the first robot 130a and returned to the load lock 120a. In this way, the workpiece is returned to the load lock from which it originally belonged. Furthermore, in this embodiment, the robot that places an unprocessed workpiece on the orientation station 140 is not the same robot that removes an aligned workpiece from the orientation station 140. Additionally, the robot that places an aligned workpiece on the platen 150 is not the same robot that removes a processed workpiece from the platen 150.

[0046] This device offers numerous advantages. By utilizing two SCARA robots, each with independently extendable and retractable arms, the system's throughput can be dramatically improved. In some tests, throughput exceeding 900 workpieces per hour can be achieved. Furthermore, if the desired throughput is lower, such as 650 workpieces per hour, the robots can operate more slowly. In fact, in some embodiments, the robots can operate slower than current existing systems at high throughputs. This improves handling reliability and the interval between preventative maintenance.

[0047] This disclosure should not be limited in scope by the specific embodiments described herein. In fact, various other embodiments and modifications of this disclosure, in addition to those described herein, will be apparent to those skilled in the art from the above description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of this disclosure. Furthermore, although this disclosure has been described herein in the context of a specific implementation in a specific environment for a particular purpose, those skilled in the art will recognize that its usefulness is not limited thereto, and that this disclosure can be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be interpreted in light of the entire scope and spirit of this disclosure as described herein.

Claims

1. A system for transporting workpieces to a platen, Two load locks, Two robots, each having two arms associated with its own load lock, and each capable of independently retracting and extending; An orientation station for aligning each workpiece before it is placed on the platen, A system that includes these features.

2. Each robot repeatedly executes a sequence, and the sequence is To move to each of the aforementioned load locks, Using the first of the two arms, processed workpieces are placed in the respective load locks, and the second of the two arms is used to remove unprocessed workpieces. To move to the orientation station, Using the first arm, the aligned workpiece is removed from the orientation station, and the second arm is used to place the unprocessed workpiece onto the orientation station. Moving to the aforementioned platen, Using the second arm, the processed workpiece is removed from the platen, and using the first arm, the aligned workpiece is placed on the platen. The system according to claim 1, comprising:

3. The system according to claim 2, wherein the second robot of the two robots executes the sequence, which is delayed compared to the sequence executed by the first robot of the two robots.

4. The system according to claim 1, wherein the first robot of the two robots removes an unprocessed workpiece from the first load lock of the two load locks and places the unprocessed workpiece on the orientation station, and the second robot of the two robots removes the unprocessed workpiece from the orientation station after alignment.

5. The system according to claim 1, wherein the first robot of the two robots takes the aligned workpiece from the orientation station and places the aligned workpiece on the platen, and the second robot of the two robots takes the aligned workpiece from the platen after processing.

6. The system according to claim 1, wherein each of the two load locks has a stacked configuration with two independent chambers.

7. The system according to claim 6, wherein each independent chamber holds two or three workpieces.

8. The system according to claim 1, wherein the two arms of each robot are fixed in the yaw direction.

9. The system according to claim 1, further comprising a plurality of forward-opening unified pods (FOUPs) and an atmospheric robot disposed in the surrounding environment, wherein the atmospheric robot transports a workpiece between the two load locks and the FOUPs.

10. The system according to claim 9, wherein the atmospheric robot has a 1+N pick arrangement, and the atmospheric robot enables the transfer of one, N, or N+1 workpieces at a time between the FOUP and the two load locks.

11. A method for transferring a workpiece between multiple load locks and platens, Executing a sequence of processes, wherein the sequence is The process involves placing a processed workpiece in one of the aforementioned load locks and removing an unprocessed workpiece. The process involves removing the aligned workpiece from the alignment station and placing the unprocessed workpiece on the alignment station, The process involves removing the processed workpiece from the platen and placing the aligned workpiece on the platen. To have, to perform A method that includes [a certain feature].

12. The method according to claim 11, further comprising repeating the sequence multiple times.

13. The method according to claim 11, wherein the sequence is performed by a first robot.

14. The method according to claim 13, wherein the sequence is also executed by a second robot and is delayed compared to the sequence executed by the first robot.

15. The method according to claim 14, wherein the first robot removes the unprocessed workpiece from the first load lock among the plurality of load locks, places the unprocessed workpiece on the orientation station, and the second robot removes the unprocessed workpiece from the orientation station after alignment.

16. The method according to claim 15, wherein the second robot takes the aligned workpiece from the orientation station and places the aligned workpiece on the platen, and the first robot takes the aligned workpiece from the platen after processing.

17. The method according to claim 14, wherein the first robot transfers a workpiece to and from a first load lock among the plurality of load locks, and the second robot transfers a workpiece to and from a second load lock among the plurality of load locks.

18. The method according to claim 11, wherein each of the plurality of load locks has a stacked configuration having two independent chambers.

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