Workpiece carrying framework with high workpiece yield

Abstract

A system for transferring semiconductor workpieces from a load lock to an orientation station and onto a platen is disclosed. The system comprises two loading locks, two manipulators and an orientation station. Each manipulator is associated with a respective load lock and follows a fixed sequence. The manipulator returns the processed workpiece to the load lock and also removes the unprocessed workpiece. The robot is then moved to an orientation station in which the robot moves the aligned workpiece from the orientation station and places the untreated workpiece on the orientation station. Next, the robot is moved to a platen in which the robot moves out the processed workpiece and places the aligned workpiece. The manipulator then returns to the load lock and repeats this sequence.

Description

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

[0002] Embodiments relate to a system for achieving high workpiece throughput, and more particularly to a system for achieving higher throughput when processing semiconductor workpieces. Background Art

[0003] Ions are used in a number of semiconductor processes such as implantation processes, amorphization processes, deposition processes, and etching processes. These semiconductor processes are typically carried out in a process chamber maintained under near-vacuum conditions.

[0004] Before a semiconductor workpiece can be processed, it is transported from the surrounding environment to the process chamber. Additionally, after the semiconductor workpiece is transported to the process chamber, it is typically aligned in a specific orientation.

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

[0006] Transferring the workpiece from the load lock to the orientation station and then to the platen can often represent a bottleneck in the semiconductor process. For example, processing the workpiece on the platen may take less than 5 seconds, which in an ideal scenario would allow for at least 720 workpieces to be processed per hour. However, traditional transport systems limit throughput to approximately 500 workpieces per hour.

[0007] Accordingly, there is a need for a system that transports workpieces between the load lock and the platen such that semiconductor processing is not a bottleneck in the process. Summary of the Invention

[0008] Disclosed is a system for transferring semiconductor workpieces from a load lock to an orientation station and to a platen. The system includes two load locks, two manipulators, and an orientation station. Each manipulator is associated with a corresponding load lock and follows a fixed sequence. The manipulator returns processed workpieces to the load lock and also removes unprocessed workpieces. Then, the manipulator moves to the orientation station, where the manipulator removes aligned workpieces from the orientation station and places the unprocessed workpieces on the orientation station. Next, the manipulator moves to the platen, where the manipulator removes the processed workpieces and places the aligned workpieces. Then, the manipulator returns to the load lock and repeats this sequence.

[0009] According to one embodiment, a system for transporting a plurality of workpieces to a platen is disclosed. The system includes: two load locks; two manipulators, each of the two manipulators being associated with a corresponding one of the two load locks, and each of the two manipulators having two arms that can be independently retracted and extended; and an orientation station for aligning each of the plurality of workpieces before placing each of the plurality of workpieces on the platen. In some embodiments, each of the two manipulators repeatedly executes a sequence, where the sequence includes: moving to the corresponding load lock; placing a processed workpiece in the corresponding load lock using the first arm of the two arms and removing an unprocessed workpiece using the second arm of the two arms; moving to the orientation station; removing an aligned workpiece from the orientation station using the first arm and placing the unprocessed workpiece on the orientation station using the second arm; moving to the platen; and removing the processed workpiece from the platen using the second arm and placing the aligned workpiece on the platen using the first arm. In certain embodiments, the second manipulator of the two manipulators executes the sequence, and there is a delay compared to the sequence executed by the first manipulator of the two manipulators. In some embodiments, the first manipulator of the two manipulators removes an unprocessed workpiece from the first load lock of the two load locks and places the unprocessed workpiece on the orientation station, and wherein the second manipulator of the two manipulators removes the unprocessed workpiece from the orientation station after the unprocessed workpiece is aligned. In some embodiments, the first manipulator of the two manipulators removes the aligned workpiece from the orientation station and places the aligned workpiece on the platen, and wherein the second manipulator of the two manipulators removes the aligned workpiece from the platen after the aligned workpiece is processed. In some embodiments, each of the two load locks has a stacked configuration having two independent chambers. In certain embodiments, each of the two independent chambers accommodates 2 or 3 of the plurality of workpieces. In some embodiments, the two arms of each of the two manipulators are fixed in a yaw direction. In some embodiments, the system further includes a plurality of front opening unified pods (FOUPs) and atmospheric robots disposed in the surrounding environment, wherein the atmospheric robots transfer a plurality of workpieces between the two load locks and the plurality of FOUPs. In certain embodiments, the atmospheric robot has a 1+N pick-up arrangement, enabling the atmospheric robot to transfer 1, N, or N+1 of the plurality of workpieces at a time between the plurality of FOUPs and the two load locks.

[0010] According to another embodiment, a method for transferring a plurality of workpieces between a plurality of load locks and a platen is disclosed. The method includes performing a sequence of processes, the sequence including: placing a processed workpiece in one of the plurality of load locks and removing an unprocessed workpiece; removing an aligned workpiece from an orientation station and placing the unprocessed workpiece on the orientation station; and removing the processed workpiece from the platen and placing the 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, with a delay compared to the sequence performed by the first robot. In certain embodiments, the first robot removes the unprocessed workpiece from a first load lock of the plurality of load locks and places the unprocessed workpiece on the orientation station, and wherein the second robot removes the unprocessed workpiece from the orientation station after the unprocessed workpiece is aligned. In certain embodiments, the second robot removes the aligned workpiece from the orientation station and places the aligned workpiece on the platen, and wherein the first robot removes the aligned workpiece from the platen after the aligned workpiece is processed. In some embodiments, the first robot transfers the plurality of workpieces to and from a first of the plurality of load locks, and the second robot transfers the plurality of workpieces to and from a second of the plurality of load locks. In some embodiments, each of the plurality of load locks has a stacked configuration having two independent chambers. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To better understand the present disclosure, reference is made to the accompanying drawings incorporated herein by reference and in which:

[0012] Figure 1 FIG. shows a system for transporting workpieces according to one embodiment.

[0013] Figure 2 FIG. shows a load lock according to one embodiment.

[0014] Figure 3 FIG. shows a side view of a multi-pick robot according to one embodiment.

[0015] Figure 4 FIG. is a flowchart showing an operation sequence performed by one robot.

[0016] Figure 5 FIG. is a flowchart showing an operation sequence for processing a workpiece and returning the workpiece to a load lock. DETAILED DESCRIPTION

[0017] Figure 1Shows an embodiment of a system for transporting workpieces. The system includes a plurality of FOUPs 100 (Front Opening Unified Pods). The Equipment Front End Module (EFEM) 101 includes an atmospheric robot 110 for removing and replacing workpieces from the FOUP 100. The atmospheric robot 110 may have a 2+1 pick-up arrangement, enabling the atmospheric robot 110 to transfer 1 workpiece, 2 workpieces, or 3 workpieces during each exchange. In other words, the atmospheric robot 110 has two separate controllable arms, which is also referred to as dual yaw. In this embodiment, one of the arms has two pick-up parts that move together, while the second arm has one pick-up part. In another embodiment, the atmospheric robot 110 may have a 1+1 pick-up arrangement, enabling the atmospheric robot 110 to transfer 1 workpiece or 2 workpieces during each exchange. In another embodiment, the atmospheric robot 110 may have a 1+N pick-up arrangement, where N is 1 or greater than 1.

[0018] The atmospheric robot 110 is used to move workpieces between the FOUP 100 and the load locks 120a, 120b. In this figure, there are two load locks, namely the first load lock 120a and the second load lock 120b. Generally speaking, assuming that the atmospheric robot 110 has a 1+N pick-up arrangement, the atmospheric robot 110 can transfer N+1 workpieces, N workpieces, or 1 workpiece at a time.

[0019] The load locks 120a, 120b are used to separate the process chamber 10 from the surrounding environment 20.

[0020] In one embodiment, as Figure 2 shown, the load locks 120a, 120b may each be in a stacked configuration. Thus, each of the load locks 120a, 120b includes two separate controllable chambers 121a, 121b. In this way, the first chamber 121a of the first load lock 120a can be open to the process chamber 10, and the second chamber 121b can be open or not open to the process chamber 10. In this way, one chamber can transfer unprocessed workpieces to the process chamber 10, while the second chamber can return the processed workpieces to the surrounding environment 20.

[0021] Each chamber of the load lock is capable of accommodating multiple workpieces. In one embodiment, each chamber accommodates 2 workpieces. In another embodiment, each chamber may accommodate 3 workpieces. Of course, if necessary, the chamber can also accommodate more workpieces.

[0022] There are two manipulators 130a and 130b provided in the process chamber 10. The two manipulators 130a and 130b can be Selective Compliance Articulated Robotic Arm (SCARA) type manipulators. The SCARA type manipulator can move in the height direction and the radial direction and rotate in the yaw direction. In one embodiment, each of the manipulators 130a and 130b has two arms fixed in the yaw direction. These arms can extend and retract independently. Therefore, although these arms rotate and move in the height direction consistently, these arms can also move independently in the radial direction. Figure 3 A side view showing the first manipulator 130a is presented, which shows the first arm 131a retracted and the second arm 131b extended. In another embodiment, the manipulators 130a and 130b have two arms that can move independently on several axes. In this embodiment, software can be used to fix the arms in the yaw direction. In all embodiments, the manipulator has two arms that can extend and retract independently.

[0023] There is also an orientation station 140 provided in the process chamber 10. The orientation station is used to align the workpiece to a specific orientation. The workpiece usually has a notch for identifying the workpiece orientation located along the edge. The orientation station 140 is used to rotate the workpiece until the notch is in a predetermined position. The orientation station 140 in this system can only align one workpiece at a time. The orientation station 140 uses an alignment mechanism to orient the workpiece. For example, the alignment mechanism can include a sensor for detecting the notch in the workpiece. In some embodiments, the sensor can be a camera. In another embodiment, light can be provided on one side of the workpiece. The light can be directed towards the edge of the workpiece, and a sensor located on the opposite side of the workpiece is used to detect the presence of the notch. The position of the notch is determined based on the increase in the light received by the sensor. Of course, other alignment mechanisms can also be used.

[0024] The orientation station 140 is located in a position that both the first manipulator 130a and the second manipulator 130b can reach.

[0025] There is a platen 150 located away from the orientation station 140. The workpiece is placed on the platen 150 so that the workpiece can be processed. For example, the workpiece can undergo an ion implantation process, an etching process, or some other process when located on the platen 150. In some embodiments, the platen can be an electrostatic chuck. Similarly, the platen is located in a position that both the first manipulator 130a and the second manipulator 130b can reach.

[0026] The structure of the system has been described, and now the operation of each manipulator will be explained. Since each manipulator has two arms, each manipulator can manipulate two workpieces at each station. Figure 4 The operation of one manipulator is shown.

[0027] First, as Figure 4 shown in the box 300 as shown, the first manipulator 130a uses the first arm 131a to remove the unprocessed workpiece from the first load lock 120a and also uses the second arm 131b to place the processed workpiece in the first load lock 120a.

[0028] Next, as shown in box 310, the first manipulator 130a is moved so that the first manipulator 130a can reach the orientation station 140. As shown in box 320, once at the orientation station 140, the first manipulator 130a uses the second arm 131b to remove the aligned workpiece from the orientation station 140. Then, the first manipulator 130a uses the first arm 131a to place the unprocessed workpiece on the orientation station.

[0029] As shown in box 330, then the first manipulator 130a moves to the platen 150. As shown in box 340, at the platen 150, the first manipulator 130a uses the first arm 131a to remove the processed workpiece from the platen 150. Then the first manipulator 130a uses the second arm 131b to place the aligned workpiece on the platen.

[0030] As shown in box 350, then the first manipulator 130a moves to the load lock 120a. Then this sequence is repeated.

[0031] Note that the second manipulator 130b also performs the same sequence as shown in Figure 4 , but lags behind the first manipulator 130a. In this way, the two manipulators 130a, 130b cooperate to move the workpieces to and from the load locks.

[0032] Figure 5 A detailed flowchart showing the operation sequence implemented by the two manipulators 130a, 130b is shown. In this example, letters are used to label the workpieces already in progress, and numbers are used to label the workpieces entering the process chamber during this sequence.

[0033] When this sequence starts, there are already several workpieces in the process chamber 10. These workpieces include workpiece A which is an arm of the first manipulator 130a, workpiece B on the platen 150, workpiece C transferred from the orientation station 140 to the platen 150, and workpiece D on the orientation station 140. Therefore, Figure 5 the first few processes shown in

[0034] As shown in block 500, the first robot arm 130a places the processed workpiece A in the load lock 120a using one arm of the first robot arm 130a and removes the unprocessed workpiece 1 using the other arm of the first robot arm 130a.

[0035] Roughly simultaneously, as shown in block 505, the second robot arm 130b removes the processed workpiece B from the platen 150 and places the aligned workpiece C on the platen 150.

[0036] Next, as shown in block 510, the first robot arm 130a removes the aligned workpiece D from the orientation station 140 and places the unprocessed workpiece 1 on the orientation station 140.

[0037] Roughly simultaneously, as shown in block 515, the second robot arm 130b places the processed workpiece B in the load lock 120a using one arm of the second robot arm 130b and removes the unprocessed workpiece 2 using the other arm of the second robot arm 130b.

[0038] Next, as shown in block 520, the first robot arm 130a removes the processed workpiece C from the platen 150 and places the aligned workpiece D on the platen 150.

[0039] Roughly simultaneously, as shown in block 525, the second robot arm 130b removes the aligned workpiece 1 from the orientation station 140 and places the unprocessed workpiece 2 on the orientation station 140.

[0040] As shown in block 530, the first robot arm 130a places the processed workpiece C in the load lock 120a using one arm of the first robot arm 130a and removes the unprocessed workpiece 3 using the other arm of the first robot arm 130a.

[0041] Roughly simultaneously, as shown in block 535, the second robot arm 130b removes the processed workpiece D from the platen 150 and places the aligned workpiece 1 on the platen 150.

[0042] Next, as shown in block 540, the first robot arm 130a removes the aligned workpiece 2 from the orientation station 140 and places the unprocessed workpiece 3 on the orientation station 140.

[0043] Roughly simultaneously, as shown in block 545, the second robot arm 130b places the processed workpiece D in the load lock 120a using one arm of the second robot arm 130b and removes the unprocessed workpiece 4 using the other arm of the second robot arm 130b.

[0044] Next, as shown in block 550, the first robot arm 130a removes the processed workpiece 1 from the platen 150 and places the aligned workpiece 2 on the platen 150.

[0045] Roughly simultaneously, as shown in block 555, the second robot arm 130b removes the aligned workpiece 3 from the orienting station 140 and places the unprocessed workpiece 4 on the orienting station 140.

[0046] As shown in block 560, the first robot arm 130a places the processed workpiece 1 in the load lock 120a using one arm of the first robot arm 130a and removes the unprocessed workpiece 5 using the other arm of the first robot arm 130a.

[0047] Roughly simultaneously, as shown in block 565, the second robot arm 130b removes the processed workpiece 2 from the platen 150 and places the aligned workpiece 3 on the platen 150.

[0048] Note that blocks 500, 510, 525, 535, 550, and 560 illustrate the sequence of operations that the workpiece 1 undergoes. Thus, in this embodiment, the workpiece removed from the load lock 120a by the first robot arm 130a is placed on the orienting station 140 using the first robot arm 130a. Then the workpiece is removed from the orienting station 140 and placed on the platen 150 using the second robot arm 130b. Finally, the workpiece is removed and returned to the load lock 120a using the first robot arm 130a. In this way, the workpiece is returned to the load lock from which it originally came. Additionally, in this embodiment, the robot arm that places the unprocessed workpiece on the orienting station 140 is different from the robot arm that removes the aligned workpiece from the orienting station 140. Further, the robot arm that places the aligned workpiece on the platen 150 is different from the robot arm that removes the processed workpiece from the platen 150.

[0049] This apparatus has many advantages. By using two SCARA robot arms having two arms that can be independently extended and retracted, the throughput of the system can be significantly increased. In some tests, a throughput of over 900 workpieces per hour can be achieved. Additionally, if a lower throughput is desired (e.g., 650 workpieces per hour), the robot arms may be able to move more slowly. In fact, in some embodiments, the robot arms may be slower at high throughput than current existing systems. This increases the reliability of handling and the time between preventative maintenance.

[0050] The scope of the present disclosure is not limited to the scope of the specific embodiments described herein. In fact, upon reading the foregoing description and the accompanying drawings, various other embodiments of the present disclosure and various modifications to the present disclosure will be apparent to those of ordinary skill in the art in addition to the embodiments and modifications described herein. Accordingly, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Moreover, although the present disclosure has been described in the context of specific embodiments in a specific environment for a specific purpose, those of ordinary skill in the art will recognize that the utility of the present disclosure is not limited thereto and that the present disclosure can be beneficially implemented for any number of purposes in any number of environments. Therefore, the claims set forth above should be understood in light of the full scope and spirit of the present disclosure described herein.

Claims

1. A system for transporting multiple workpieces to a platen, comprising: two loading locks; two manipulators, each of the two manipulators being associated with a corresponding one of the two loading locks, and each of the two manipulators having two arms that can be independently retracted and extended; and an orientation station for aligning each of the multiple workpieces before placing each of the multiple workpieces on the platen.

2. The system according to claim 1, wherein each of the two manipulators repeatedly executes a sequence, and the sequence comprises: moving to the corresponding loading lock; placing a processed workpiece in the corresponding loading lock using a first arm of the two arms and removing an unprocessed workpiece using a second arm of the two arms; moving to the orientation station; removing an aligned workpiece from the orientation station using the first arm and placing the unprocessed workpiece on the orientation station using the second arm; moving to the platen; and removing the processed workpiece from the platen using the second arm and placing the aligned workpiece on the platen using the first arm.

3. The system according to claim 2, wherein the second of the two manipulators executes the sequence, with a delay compared to the sequence executed by the first of the two manipulators.

4. The system according to claim 1, wherein the first of the two manipulators removes an unprocessed workpiece from a first loading lock of the two loading locks and places the unprocessed workpiece on the orientation station, and wherein the second of the two manipulators removes the unprocessed workpiece from the orientation station after the unprocessed workpiece has been aligned.

5. The system according to claim 1, wherein the first of the two manipulators removes an aligned workpiece from the orientation station and places the aligned workpiece on the platen, and wherein the second of the two manipulators removes the aligned workpiece from the platen after the aligned workpiece has been processed.

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

7. The system according to claim 6, wherein each of the two independent chambers accommodates 2 or 3 of the multiple workpieces.

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

9. The system according to claim 1, further comprising a plurality of front-opening unified pods (FOUPs) and atmospheric robots disposed in the surrounding environment, wherein the atmospheric robots transfer multiple workpieces between the two loading locks and the plurality of front-opening unified pods.

10. The system according to claim 9, wherein the atmospheric robot has a 1+N pick-up arrangement, enabling the atmospheric robot to transfer 1 workpiece, N workpieces, or N+1 workpieces of the multiple workpieces at a time between the plurality of front-opening unified pods and the two loading locks.

11. A method for transferring a plurality of workpieces between a plurality of load locks and a platen, comprising: performing a sequence of processes, the sequence including: placing a processed workpiece in one of the plurality of load locks and removing an unprocessed workpiece; removing an aligned workpiece from an orientation station and placing the unprocessed workpiece on the orientation station; and removing the processed workpiece from the platen and placing the aligned workpiece on the platen.

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 performed by a second robot with a delay compared to the sequence performed by the first robot.

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

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

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