Wafer handling robot equipped with a gravity field sensor

Abstract

Techniques and systems are disclosed for automatically determining and correcting the levelness of an end effector of a wafer handling robot. The system may use a tilt sensor or a gravity field sensor. The tilt sensor or gravity field sensor may be calibrated to the wafer handling robot. Output from the tilt sensor may be used to determine or estimate the tilt of the end effector of the wafer handling robot and perform corrective alignment to reduce or eliminate the tilt, which may automatically teach a specific position with reduced tilt, diagnose the robot, provide feedback to a user, etc.

Description

Background Art

[0001] Semiconductor processing apparatuses generally have a wafer handling robot. The wafer handling robot is used to pick up wafers from a front-opening unified pod (FOUP) or a wafer station, transport the wafers within the processing apparatus, and place the wafers on the FOUP or the wafer station. A general wafer handling robot includes a controller, a central base or body, and robot arm links rotatably connected in series. The proximal link is rotatably connected to the base, and the distal link is a blade-type end effector used for transporting wafers. The robot arm links are driven by a drive system including motors, belts, and pulleys that can rotate and extend / contract the robot arm links. Encoders may be used to provide position feedback information to the controller. The controller may use this information to determine the position of the wafer handling robot and control the movement of the motors to position the wafer handling robot in other configurations.

Summary of the Invention

[0002] One or more implementations of the subject matter described in this specification are detailed in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the following description, the drawings, and the claims.

[0003] In some implementations, an apparatus may be provided that includes a first robotic arm having a base, one or more first robotic arm links, one or more motors, a tilt sensor, and a mechanism. One or more of the one or more first robotic arm links may be an end effector configured to support a semiconductor wafer. One or more of the one or more first robotic arm links may have an end rotatably connected to the base. The tilt sensor may be a gravity field sensor configured to detect an orientation with respect to the Earth's gravity field, and may be fixedly attached to one of the one or more first robotic arm links or to the base. The mechanism may support the first robotic arm and may be configured to rotate the first robotic arm about a horizontal pitch axis in response to one or more inputs.

[0004] In some implementations of the apparatus, the mechanism may include a gimbal configured to support the base of the first robotic arm.

[0005] In some implementations of the apparatus, the mechanism may be a second robotic arm. The second robotic arm may have one or more second robotic arm links and one or more second robotic arm rotation joints. Each of the one or more second robotic arm rotation joints may have a horizontal rotation axis, and each of the second robotic arm links may be rotatably connected by one of the one or more second robotic arm rotation joints to at least one of the other second robotic arm links. The second robotic arm may be configured to support the base of the first robotic arm.

[0006] In some implementations of the apparatus, the tilt sensor may be an accelerometer.

[0007] In some implementations of the apparatus, the tilt sensor may be an inclinometer.

[0008] In some implementation forms of the device, the tilt sensor may be fixedly attached to the base.

[0009] In some implementation forms of the device, the tilt sensor may be fixedly attached to the instrumented first robot arm link among the one or more first robot arm links.

[0010] In some implementation forms of the device, two or more first robot arm links may be provided, and the instrumented first robot arm link may be the first robot arm link that directly or indirectly supports each of the other one or more first robot arm links.

[0011] In some implementation forms of the device, the instrumented first robot arm link may be one of the one or more end effectors.

[0012] In some implementation forms of the device, three or more first robot arm links may be provided, and the three or more first robot arm links may include a proximal first robot arm link, a distal first robot arm link, and the instrumented first robot arm link. The instrumented first robot arm link may be rotatably connected to the proximal first robot arm link by a proximal first robot arm rotary joint at a first end, and may be rotatably connected to the distal first robot arm link by a distal first robot arm rotary joint at a second end opposite to the first end.

[0013] In some implementations, the apparatus may further include a controller having one or more processors and one or more memory devices. The one or more processors and the one or more memory devices may be operably connected, the one or more processors may be communicably connected to the tilt sensor, the one or more memory devices may store computer-executable instructions, and the computer-executable instructions may be executed by the one or more processors to cause the one or more processors to receive first sensor data generated by the tilt sensor when the instrumented first robotic arm link is in a first angular position relative to the base, rotate the instrumented first robotic arm link to a second angular position relative to the base, receive second sensor data generated by the tilt sensor when the instrumented first robotic arm link is in the second angular position, and determine calibration data for the tilt sensor based on the first sensor data and the second sensor data.

[0014] In some implementations of the apparatus, the second angular position may be a position 180° from the first angular position.

[0015] In some implementations of the apparatus, the one or more memory devices may store additional instructions that, when executed, cause the one or more processors to move at least one of the one or more end effectors to a position associated with the wafer station, receive sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, determine a pitch angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, rotate the mechanism about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the threshold pitch angle range when the pitch angle of the tilt sensor is outside the threshold pitch angle range, and record in at least one of the one or more memory devices an association of the taught position of the mechanism and the first robotic arm with the wafer station, where the taught position indicates the position of the mechanism and the first robotic arm when the at least one end effector is at the position associated with the wafer station and the pitch angle of the tilt sensor is within the threshold pitch angle range.

[0016] In some implementations of the apparatus, the one or more memory devices may further store additional instructions that, when executed, cause the one or more processors to move the mechanism and the first robotic arm to the taught position when placing a wafer on the first robotic arm at the wafer station.

[0017] In some implementations of the device, the one or more memory devices may store additional instructions, and execution of the additional instructions causes the one or more processors to move at least one of the one or more end effectors to a position associated with the wafer station, receive sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, determine the pitch angle of the tilt sensor and the roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, rotate the mechanism about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the threshold pitch angle range when the pitch angle of the tilt sensor is outside the threshold pitch angle range, compare the roll angle of the tilt sensor with a threshold roll angle range, rotate the mechanism about a horizontal rotation axis so that the roll angle of the tilt sensor is within the threshold roll angle range when the roll angle of the tilt sensor is outside the threshold roll angle range, and record the taught positions of the mechanism and the first robotic arm in at least one of the one or more memory devices in association with the wafer station, where the taught positions indicate the positions of the mechanism and the first robotic arm when the at least one end effector is at the position associated with the wafer station, the pitch angle of the tilt sensor is within the threshold pitch angle range, and the roll angle of the tilt sensor is within the threshold roll angle range.

[0018] In some implementations of the device, the one or more memory devices may store additional instructions, and execution of the additional instructions causes the one or more processors to move at least one of the one or more end effectors to a position associated with the wafer station, receive sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, determine a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, and present information indicating the roll angle of the tilt sensor.

[0019] In some implementations of the apparatus, the one or more memory devices may store additional instructions, and execution of the additional instructions causes the one or more processors to cause at least one of the one or more end effectors to pick up and support a wafer, move the at least one end effector and the wafer supported by the at least one end effector to a position associated with a wafer station, receive sensor data generated by the tilt sensor when the at least one end effector and the wafer supported by the at least one end effector are at the position associated with the wafer station, determine a pitch angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, rotate the first robotic arm about a horizontal rotation axis of the mechanism so that the pitch angle of the tilt sensor is within the threshold pitch angle range when the pitch angle of the tilt sensor is outside the threshold pitch angle range, and after the pitch angle of the tilt sensor is within the threshold pitch angle range, move the at least one end effector to the first robotic arm and place the wafer on the wafer station.

[0020] In some implementations of the apparatus, the one or more memory devices may store additional instructions, which when executed, cause the one or more processors to cause at least one of the one or more end effectors to retrieve and support a wafer, move the at least one end effector and the wafer supported by the at least one end effector to a location associated with a wafer station, receive sensor data generated by the tilt sensor when the at least one end effector and the wafer supported by the at least one end effector are at the location associated with the wafer station, determine a pitch angle and a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the location associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, rotate the first robotic arm of the mechanism about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the threshold pitch angle range if the pitch angle of the tilt sensor is outside the threshold pitch angle range, compare the roll angle of the tilt sensor with a threshold roll angle range, rotate the first robotic arm of the mechanism about a horizontal rotation axis so that the roll angle of the tilt sensor is within the threshold roll angle range if the roll angle of the tilt sensor is outside the threshold roll angle range, and after the pitch angle of the tilt sensor is within the threshold pitch angle range, move the at least one end effector to the first robotic arm and place the wafer on the wafer station.

[0021] The above and other features of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Brief Description of the Drawings

[0022] The various implementations disclosed in this specification are shown in each figure of the accompanying drawings by way of example and not for the purpose of limitation. In the figures, like components are denoted by the same reference numerals.

[0023]

Figure 1

[0024]

Figure 2-1

Figure 2-2

Figure 2-3

[0025]

Figure 3-1

Figure 3-2

[0026]

Figure 4

[0027]

Figure 5-1

Figure 5-2

[0028]

Figure 6

[0029]

Figure 7

[0030]

Figure 8-1

Figure 8-2

Figure 8-3

[0031]

Figure 9

[0032]

Figure 10-1

Figure 10-2

[0033] These drawings merely illustrate an example of the concepts described in this specification. As can be readily appreciated, the concepts described in this specification may be implemented in many alternative embodiments, and all of these embodiments are considered to be within the scope of the present disclosure.

Best Mode for Carrying Out the Invention

[0034] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented embodiments. The embodiments of the present disclosure may be practiced without some or all of these specific details. In other instances, well-known process steps are not described in detail in order to avoid unnecessarily obscuring the embodiments of the present disclosure. Further, the embodiments of the present disclosure are described in relation to specific embodiments, but it is understood that these specific embodiments are not intended to limit the scope of the embodiments of the present disclosure.

[0035] A wafer handling robot is used for transporting wafers in a semiconductor manufacturing process. A wafer handling robot requires precise movement to transport a wafer from one processing step to the next, and in order to achieve such precise placement, it often has a control system that utilizes a kinematic model in cooperation with sensor measurement values and a motor control system. When determining the next movement to move the wafer handling robot to a desired position, the controller may use feedback from one or more encoders. The kinematic model may enable the controller to use feedback from the encoders to determine the position and orientation of a given robotic arm link (e.g., the position and orientation of the end effector). Based on the current position and orientation of a given robotic arm link and the desired position, the kinematic model may be used to determine how much rotational input of the motor is required to move a given wafer handling robotic arm link from its original position and orientation to a new position and orientation. The controller may rotate one or more motors with the determined rotational input to drive a given wafer handling robotic arm link to the desired position. During such movement, the encoder may continue to supply feedback to the controller, thereby implementing a closed-loop system that enables the controller to continuously correct the operation of the motor to achieve the desired placement. For example, if the wafer handling robotic arm link is not in the desired position, the controller may use the kinematic model to determine the additional rotational input required by the motor to drive a given wafer handling robotic arm link to the desired position, and operate the motor by that additional rotational input to drive the wafer handling robotic arm link to the desired position. Then, the controller may check the encoder after driving the robotic arm link by the motor to determine the position of the wafer handling robotic arm link. If the robotic arm link is not in the desired position, this process may be repeated until a given robotic arm link is moved to the desired position.

[0036] Wafer handling robot arms are typically designed to use the minimum number of wafer handling robot arm links necessary to perform the required movements. By minimizing the number of wafer handling robot arm links, the design is simplified, problems are reduced, and costs are lowered. The fewer the number of wafer handling robot arm links, the fewer the components required for the wafer handling robot, and the more space available for mounting the required components, resulting in a simpler design for the wafer handling robot. As important as design simplification, reducing the number of wafer handling robot arm links can also reduce the tolerance problems of the wafer handling robot, such as mechanical tolerance accumulation and deflection issues. A wafer handling robot may have an allowable value for mechanical tolerance accumulation, and when an individual wafer handling robot arm link is added, the tolerance given to other components, including other wafer handling robot arm links, may decrease. The more the number of wafer handling robot arm links increases, the more precision is required for individual wafer handling robot arm links to meet a specific overall target tolerance. When the mechanical tolerance accumulation of the wafer handling robot arm link exceeds the tolerance allowable value, problems are more likely to occur. These problems include, in particular, the increased likelihood of component chipping, increased and / or faster wear of components, and / or increased force applied to components, and additional deflection occurring in components. There is also a problem that the wafer handling robot arm may deflect when the number of wafer handling robot arm links of the wafer handling robot arm is large. When the wafer handling robot arm is in a fully extended position, the wafer handling robot arm link may act as a cantilever beam. Therefore, adding each link to the wafer handling robot may increase deflection due to the force applied by each wafer handling robot arm link and / or looseness in the assembly of the wafer handling robot arm link to the wafer handling robot.Due to this deflection, the end effector may be positioned at an unexpected height or angle, and as a result, during use, the end effector or the wafer may collide, i.e., hit other parts of the device. To prevent or mitigate these problems, when using more robot arm links, each robot arm link may be designed with stricter tolerances, but this leads to an increase in cost per individual robot arm link. The combination of the increased cost per individual robot arm link and the cost of purchasing more links can cause the cost of a wafer handling robot with more robot arm links to increase dramatically compared to a similar robot with fewer robot arm links. Therefore, wafer handling robots tend to be designed with fewer robot arm links and rotational joints. This is because each additional such rotational joint and robot arm link can increase the complexity, potential problems, and cost of the wafer handling robot arm.

[0037] FIG. 1 is a diagram showing one embodiment of a wafer handling robot 100. Different from a standard wafer handling robot, the wafer handling robot 100 typically has fewer links and restricts the rotational movement of the robot components to rotation around a vertical axis (thus keeping the end effector and the robot arm links generally horizontal and reducing or minimizing the number of rotational joints that can cause a decrease in the accuracy of such a wafer handling robot). The wafer handling robot 100 may include a wafer handling robot arm 102 (which may also be referred to as an upper robot herein) and a mechanism 104 communicatively connected to a controller 106. The wafer handling robot arm may be attached to the mechanism 104 such that the mechanism 104 can impart at least one or more amounts of rotation around a horizontal axis to the wafer handling robot arm during its operation. In this example, as will be described later, the mechanism itself is another robot arm, but in other implementations, the mechanism may be in other forms, such as a gimbal mount.

[0038] As can be seen from FIG. 1, the wafer handling robot arm 102 has a base 108. The base 108 may be connected to and supported by the mechanism 104. As shown in FIG. 1, the wafer handling robot arm 102 has two wafer handling robot arm links 110a and 110b. The first wafer handling robot arm link 110a is rotatably connected to the base 108 by a rotary joint 111a that enables the first wafer handling robot arm link 110a to rotate around the axis 118a. The second wafer handling robot arm link 110b is rotatably connected to the first wafer handling robot arm link 110a by a second rotary joint 111b so as to be rotatable around the axis 118b. As shown in FIG. 1, the second wafer handling robot arm link 110b may be an end effector 112 that can be used for transporting the wafer 138. It is understood that the wafer handling robot arm 102 may include a different number of robot arm links from those shown. For example, it may include a plurality of robot arm links connected to rotary joints configured to rotate around a common axis (for example, two second wafer handling robot arm links 110b both rotatably connected to the wafer handling robot arm link 110a by corresponding rotary joints 111b, and for example, a dual end effector 112 may be realized thereby). Therefore, the examples provided herein are for illustrative purposes only.

[0039] The wafer handling robot arm 102 has at least one wafer handling robot arm link 110. In some implementations, a single wafer handling robot arm link that can also function as an end effector may be provided. In other implementations, as shown in FIG. 2-1, a plurality of wafer handling robot arm links such as 110a and 110b may be provided. In such an implementation, at least one of the wafer handling robot arm links is the end effector 112.

[0040] FIG. 2-1 is a top view of the wafer handling robot arm 102. FIGS. 2-2 and 2-3 are a side view and an isometric view of this wafer handling robot arm 102, respectively. The wafer handling robot arm 102 has a motor 214 that can be controlled to drive the movement of the wafer handling robot arm. In some embodiments, a plurality of motors may be provided. In FIG. 2, the motor 214 is fixedly attached to the base 108. The motor may be fixedly attached to the base 108 within the wafer handling robot arm link 110, within the rotary joint 111, or at other locations within the wafer handling robot arm (particularly in more complex robot arms having a plurality of motors, one or more motors may be fixedly attached to one of the robot arm links).

[0041] The wafer handling robot arm 102 may include an encoder 217. In FIG. 2, the encoder 217 is disposed within a first wafer handling robot arm link 110a near the rotary joint 111. A rotary encoder such as the encoder 217 typically includes a sensor head and an encoder disk or similar encoder reference, which are respectively attached to different ones of two components that are rotatably connected to each other. In some implementations, the encoder may be disposed within the motor housing. In some implementations, either the sensor head or the encoder disk may be fixedly attached to the base, and the other component may be fixedly attached to the first wafer handling robot arm link 110a. In some implementations, a single encoder may be used in the wafer handling robot arm 102. However, in other implementations, multiple encoders may be used in the wafer handling robot arm 102, for example, at least one may be provided for each rotational input source (e.g., motor). The encoder may be used to provide feedback regarding the position of the wafer handling robot arm 102, the plurality of wafer handling robot arm links 110, or a single wafer handling robot arm link to the controller.

[0042] In contrast to conventional wafer handling robots, the wafer handling robot arm 102 further includes a tilt sensor 216. As shown in FIG. 2-2, in some implementations, the tilt sensor 216 may be fixedly attached to a wafer handling robot arm link 110 connected to the base 108. However, in some other implementations, the tilt sensor may be fixedly attached to the base 108. In some implementations, the tilt sensor may be fixedly attached to the end effector 112. When the wafer handling robot has three or more links (not shown), the tilt sensor may be fixedly attached to any one of the links including the base, or a link connected to the base, an end effector link, or a link between a link connected to the base and the end effector link (the arm link to which the tilt sensor can be fixedly attached may be referred to herein as the "instrumented link" or "instrumented arm link"). Alternatively, the tilt sensor 216 may be disposed within or on the base 108. Generally, in at least most implementations, the tilt sensor is fixedly attached to any component of the arm system that is not configured to be rotatable about a horizontal axis relative to adjacent components while the wafer is horizontally supported by the end effector of the wafer handling robot, i.e., when the major surface of the wafer is horizontal.

[0043] FIG. 1 shows a mechanism 104 connected to a wafer handling robot arm 102. The mechanism 104 shown in FIG. 1 is a lower robot arm 120. However, in other implementations, the mechanism 104 may be replaced with a mechanism having a gimbal or other tiltable mount, such as that shown in FIG. 4 (described later). Returning to FIG. 1, the wafer handling robot arm 102 may be attached to and supported by the lower robot arm 120. In the illustrated implementation, the base 108 of the wafer handling robot arm 102 is attached to a lower robot wrist mount 126. Such a configuration allows the lower robot arm to move the wafer handling robot arm to a number of possible positions along a linear axis, thereby enabling the wafer to be inserted into and removed from each semiconductor processing chamber disposed along the elongated wafer transfer chamber using the wafer handling robot arm.

[0044] Figures 3-1 and 3-2 are diagrams showing the lower robot arm 120 in a state where it is not attached to the wafer handling robot arm. As shown in FIGS. 3-1 and 3-2, the lower robot arm 120 has a base plate 322. The base plate 322 and the first lower robot arm link 124a may be connected by a rotary joint 327a. The rotary joint 327a enables rotation of the first lower robot arm link 124a around the horizontal axis 130a. In some implementations, the first lower robot arm link 124a and the second lower robot arm link 124b may be connected by a second rotary joint 327b. In such an implementation, the second lower robot arm link 124b is rotatable around the horizontal axis 130b. In some implementations, the second lower robot arm link 124b and the wrist mount 126 may be connected by a wrist rotation joint 327c. In such an implementation, the lower robot wrist mount 126 is rotatable around the horizontal axis 130c. The wrist mount 126 may be moved between different positions in the YZ plane by rotating the various lower robot arm links 124 to extend and retract the lower robot arm in the Y and Z directions. To keep the wrist mount 126 horizontal during such movement, the wrist mount 126 may be rotated simultaneously with such movement.

[0045] In some implementations of the lower robot arm 120, the movement of the lower robot arm 120 may be controlled using two or more motors 328. FIG. 3-1 shows a lower robot arm equipped with a plurality of motors 328. The motors 328 may be disposed within the rotary joint 327, within the lower robot arm link 124, within the wrist mount 126, or elsewhere within the lower robot arm (one or more motors may be fixedly attached to one of the lower robot arm links or rotary joints. Alternatively, a belt pulley system may be used, whereby one or more motors are fixedly attached to the base plate 322 and the rotational input from such motors is transmitted to the driven lower arm link via the belt pulley system). Then, the motors 328 may be used to drive the movement of the lower robot. In some implementations, two or more encoders 329 may be used to determine the relative rotational positions of the various lower robot arm links. FIG. 3-1 shows a lower robot arm 120 equipped with a plurality of encoders 329. For example, the encoders 329 (e.g., encoders 329a and 329b) may be disposed at each position where two components in the robot arm link mechanism can be configured to rotate relative to each other. Then, the encoders 329 may be used to provide information on the relative rotational direction of these components to the controller so that the kinematic model of the lower robot arm can be updated.

[0046] The lower robot arm 120 may have a different number of links, rotary joints, motors, and / or encoders in various configurations, and it is understood that such variations in the configuration of the lower robot arm are also within the scope of the present disclosure. In some alternative implementations, the lower robot arm may alternatively or additionally be configured such that each arm link rotates relative to one another about a vertical axis of rotation (similar to the arm links of a wafer handling robot). In such an implementation, the wrist joint may include a mechanism that enables the wrist mount to rotate about a vertical axis of rotation and a horizontal axis of rotation relative to the arm link to which the wrist mount is most adjacent.

[0047] In the above, the implementation form in which the wafer handling robot has a pitch function by being attached to the lower robot arm provided with the wrist mount has been mainly described. However, in other implementation forms, for example, the pitch function of the wafer handling robot may be realized by using a gimbal mount that supports the wafer handling robot base. As described above, FIG. 4 is a diagram showing an example of a wafer handling robot 400 including a gimbal mount. The wafer handling robot arm 102 is attached to the mechanism 404. In the illustrated implementation, the mechanism 404 is a gimbal 432. The gimbal 432 is attached to the base 108 of the wafer handling robot arm 102 and may enable rotation of the wafer handling robot arm 102 at least about the X-axis and / or the Y-axis. Generally, the wafer handling robot 100 may include a controller 106 (see FIG. 1). The controller 106 may include one or more processors 134 and one or more memory devices 136. The one or more processors 134, the one or more memory devices 136, and various motors and encoders or other sensors of the wafer handling robot may be operably connected to each other. Thereby, for example, one or more processors may operably control various motors of the wafer handling robot, and one or more processors may receive sensor data from, for example, tilt sensors, encoders, and optionally other sensors of the wafer handling robot. The one or more memory devices 136 may store computer-executable instructions for controlling the one or more processors 134 to perform various functions or operations by the wafer handling robot as described herein. The computer-executable instructions may include, for example, instructions for causing the one or more processors 134 to calibrate a tilt sensor, read data from the tilt sensor, and / or move the wafer handling robot as described herein with respect to various techniques that may be implemented using, for example, a wafer handling robot equipped with a tilt sensor.

[0048] Wafers transported by a wafer handling robot are generally maintained horizontally. In the case of a wafer handling robot equipped with a blade type end effector, the end effector is usually maintained in an orientation such that the surface of the wafer (contact surface) contacted by the end effector of the wafer handling robot is substantially flat or horizontal, that is, the orientation of the surface of the wafer orthogonal to the direction of the earth's gravitational field at that position. Thereby, the possibility of the wafer slipping off the end effector can be reduced, and the vertical clearance range required to pass the wafer through various openings (for example, the load port to the processing chamber) can be reduced. Fig. 5-1 is a diagram showing a wafer handling robot 100 in which the contact surface 560 is horizontal. Fig. 5-2 is a diagram showing a wafer handling robot 100 in which the contact surface 560 has a pitch angle 546. The pitch angle 546 is the angle between a selected surface of the wafer handling robot arm 102 (for example, a surface parallel to the contact surface 560) and a roll axis 548 which is an axis on a horizontal plane and orthogonal to the rotation axis of the wrist mount. A general wafer handling robot depends on a control system that uses a kinematic model and an encoder to determine the position of the wafer handling robot and control its movement in order to ensure that the contact surface 560 is horizontal as described above. However, the kinematic model and the encoder may not be able to consider potential problems that may affect the actual arrangement of a given robot arm link, such as manufacturing tolerance problems, tolerance accumulation, rotational slack, and deflection. As a result, although the movement of the wafer handling robot positions the end effector in an orientation where the pitch angle 546 actually occurs on the contact surface 560 as shown in Fig. 5-2, the control system based on the kinematic model may determine that the contact surface 560 is horizontal as shown in Fig. 5-1. The pitch angle 546 may be large enough for the wafer to slip off the end effector, but as a more likely result, the wafer may fail to satisfy the vertical clearance range required for the wafer to pass through one or more openings in the processing tool. In a general wafer handling robot, there is no built-in feedback mechanism to warn the controller of the true pitch angle 546.

[0049] Returning to FIG. 2-2, the tilt sensor 216 may be used to detect the true pitch angle of the wafer handling robot arm 102, i.e., the pitch angle with respect to the earth's gravitational field in a reference plane fixed to some component of the wafer handling robot arm 102. By providing the tilt sensor 216, the wafer handling robot 100 can calibrate the levelness regardless of any deviation within the mechanism, determine the levelness as a secondary check against the encoder-based control system, and avoid relying solely on kinematic models and encoder data that are susceptible to problems such as tolerance accumulation, rotational looseness, and component deflection. The tilt sensor 216 is a gravitational field sensor. A gravitational field sensor is a sensor that uses the acceleration due to the earth's gravity to determine the orientation of the sensor with respect to the earth's gravitational field (and thus the orientation of the component to which the tilt sensor is fixedly attached). Examples of gravitational field sensors include accelerometers and inclinometers.

[0050] FIG. 6 is a flowchart for teaching various robot arm positions selected such that a wafer supported by a wafer handling robot falls within an acceptable level range based on data from a level sensor for the wafer handling robot as described herein. At block 602, the controller may move the end effector of the wafer handling robot (which may already have a wafer loaded on its end effector) to a particular target location, e.g., near the wafer station of a semiconductor processing tool (the wafer may optionally be omitted, but from the perspective of reproducing the normal use of the wafer handling robot, the weight of the wafer may be included in the most accurate load of the wafer handling robot). At block 604, the controller may receive sensor data from a tilt sensor of the wafer handling robot (e.g., a tilt sensor as described above). At block 606, the controller may determine a pitch angle of a component to which the tilt sensor is fixedly attached with respect to a reference coordinate system defined by the earth's gravitational field based on the sensor data from the tilt sensor (in some implementations, such data may be adjusted taking into account a calibration setting capable of correcting a deviation between the reference coordinate system of the tilt sensor and the reference coordinate system of the component of the wafer handling robot to which the tilt sensor is fixedly attached). An example of a pitch angle is as shown in FIG. 5-2, where in FIG. 5-2, the wafer handling robot arm 102 is tilted upward by a pitch angle 546. The pitch angle 546 is the angle between a selected plane of the wafer handling robot arm 102 (e.g., a plane parallel to the contact surface 560 in this example) and the roll axis 548.

[0051] Returning to FIG. 6, at block 608, the controller may compare the pitch angle obtained from the tilt sensor with a threshold pitch angle (the threshold pitch angle may be, for example, ±0.1°, ±0.5°, ±0.025°, ±0.015°, ±0.010°, ±0.005° from horizontal, or any value between these values, or within a threshold pitch angle range). The threshold pitch angle is the maximum amount of angular tilt from the horizontal plane on a selected surface that is considered acceptable in wafer handling (e.g., placing a wafer on a wafer station, picking up a wafer from a wafer station, or transporting a wafer between stations or other locations). If the pitch angle exceeds the threshold pitch angle, the technique may proceed to block 610. At block 610, the controller may rotate the mechanism so that the pitch angle decreases. After rotating the mechanism, the controller may return to block 604 and receive further sensor data from the tilt sensor. The controller may continue to repeat blocks 604-610 as long as the pitch angle exceeds the threshold pitch angle. If the pitch angle is within the threshold pitch angle, the controller may proceed from block 608 to block 612.

[0052] When the pitch angle is within the threshold pitch angle, at block 612, the controller may move the end effector of the wafer handling robot to a wafer station near the target position, which is the position where the end effector of the wafer handling robot is taught the precise position for picking up and placing the wafer with respect to a specific station. The wafer handling robot may be guided to the precise position (which may also be referred to as the "taught position" of the wafer handling robot). Various methods can be considered for guiding the wafer handling robot to the X, Y, and Z coordinates of the taught position. These methods may include manually moving the end effector within the wafer station. For example, the operator may use one or more fixtures that can cooperate with the feature of the end effector of the wafer handling robot functioning as a reference point and another feature fixed to the wafer station to manually move the wafer handling robot to the taught position. As another method, an automated method may be used. In this case, the wafer handling robot may use tools such as an Active Wafer Centering (AWC) system, a calibration wafer, or a combination thereof. For example, in a typical AWC configuration, a plurality of optical AWC sensors and optical beam emitters are arranged at fixed positions near the wafer station, and when the semiconductor wafer is carried into the wafer station, the semiconductor wafer is made to pass through two or more optical beams emitted from the optical beam emitter. The AWC sensors may detect that each optical beam has contacted the edge of the semiconductor wafer, so that the system can determine a reference point (e.g., the nominal center point of the semiconductor wafer) on the end effector of the wafer handling robot (note that since the exact placement of the semiconductor wafer on the end effector may be unknown, this center point may be simply an estimate or a desired center position). When the semiconductor wafer passes through two or more emitted optical beams, the AWC may determine the reference position with respect to the wafer station and use that information to move the end effector to the X and Y coordinates of the taught position.

[0053] The portion of the wafer handling robot that is adjusted to obtain the desired levelness may be maintained in a stationary state during manual or automatic teaching of the station with respect to the wafer handling robot arm (e.g., wafer handling robot arm 102). Thus, the wafer handling robot including the mechanism (such as the lower robot arm 120) and the wafer handling robot arm 102 may first be moved to the target position prior to leveling. In some implementations, the target position may be a position where the wafer handling robot arm 102 can place a wafer on a wafer station associated with that target position or pick up a wafer from that wafer station without the need for further movement of the mechanism. Thereafter, the wafer handling robot arm 102 may be leveled by adjusting the mechanism 104. After such leveling, the mechanism 104 may be maintained in a stationary state while the wafer handling robot arm 102 is actuated or otherwise moved to the desired teaching position (e.g., the position where the wafer handling robot arm 102 will be located when placing a wafer on a wafer station associated with that target position or picking up a wafer from that wafer station). When the wafer handling robot arm 102 is located at the teaching position, the positions of the wafer handling robot arm 102 and the mechanism 104 may be stored as the "teaching position" of the wafer handling robot with respect to that wafer station. The storage of the teaching position may be performed after the wafer handling robot arm 102 is placed at the final teaching position, or may be performed at multiple different stages. For example, when the desired levelness is achieved using the mechanism, data on the teaching position regarding the position of the mechanism may be stored, and thereafter, when the wafer handling robot arm 102 is located at the final teaching position, further data regarding the position of the wafer handling robot arm 102 may be stored.

[0054] This process may be repeated for a plurality of wafer stations and target positions, depending on the number of wafer stations that require "teaching" for the wafer handling robot.

[0055] At block 614, the controller may store the current positions of various wafer handling robot components as "teaching positions" in a memory device (such as one of one or more memory devices the controller has). The teaching position may be a value in the encoder of the wafer handling robot associated with a particular target position of the wafer handling robot. For example, in this case, the teaching position represents the configuration of the wafer handling robot where the wafer being transported by the wafer handling robot is considered to be acceptably horizontal. When the wafer handling robot moves to a particular target position, the controller may move the wafer handling robot so that the value indicated by the encoder converges to the stored value associated with that particular target position. Such teaching may be performed in relation to various wafer handling robot positions. For example, if the lower robot arm 120 can take four general positions during the wafer placement operation, it may be preferable to perform such wafer flatness teaching for each of these positions (and for possible additional positions, if, for example, the wafer handling robot arm 102 extends by different amounts and / or in different directions at each of these positions). Thus, depending on the position to which the wafer handling robot is moved, the robot may be controlled by an appropriate teaching position.

[0056] In some implementations, a technique for teaching various positions of a robot arm selected to keep a wafer supported by a wafer handling robot within an acceptable level range, as shown in FIG. 6, may be used in real time to actively level the wafer supported by the wafer handling robot during normal wafer handling operations. For example, the controller may move the end effector of the wafer handling robot to a target position, receive sensor data from a tilt sensor, determine the wafer pitch angle based on the sensor data, and compare the pitch angle with a threshold pitch angle. When the pitch angle is outside the range of the threshold pitch angle, the controller may rotate the mechanism so that the pitch angle decreases. When the pitch angle is within the range of the threshold pitch angle, the controller may continue the operation of the wafer handling robot (for example, the operation of placing the wafer on the wafer station). Using this technique, the wafer handling robot may be continuously and actively leveled throughout the movement of the wafer handling robot, or the wafer handling robot may be actively leveled at the target position. The main difference between this method and the "teaching" method is that in the "teaching" method, a tilt sensor can be used to determine which encoder value represents an appropriate "horizontal" arrangement, and during normal wafer transfer operations, the level is achieved by a general encoder-based kinematic model type approach. In the latter case, the encoder can be used to generally position the arm in a desired arrangement, and then the output of the tilt sensor can be used to finely adjust the position of the wafer handling robot to ensure that the wafer carried by the wafer handling robot is horizontally level to an acceptable extent.

[0057] In some implementations, techniques for teaching various positions of a robotic arm selected to keep a wafer supported by a wafer handling robot within an acceptable levelness range, as described above with reference to FIG. 6, may be used periodically to verify and / or correct previous taught positions, taking into account potential drift or other variations in the wafer handling robot. For example, the controller may be configured to use techniques for teaching various robotic arm positions at various intervals selected by the user during operation of the semiconductor processing tool. The intervals may be, for example, time-based schedules, wafer or placement-based schedules (such as every 250 wafers placed, every 200 wafers processed, etc.). In some implementations, the controller may be programmed to check the positions taught using the teaching technique at various specified periods. In a periodic check, if the pitch angle is initially outside the range of the threshold pitch angle, the controller may put the mechanism in a teaching mode and rotate it to decrease the pitch angle. The controller may continue the teaching process for the wafer handling robot until the pitch angle is within the range of the threshold pitch angle. When the pitch angle is within the range of the threshold pitch angle, the controller may store the encoder value associated with that position in memory as the updated taught position. During the check, if the pitch angle is initially within the range of the threshold pitch angle, the controller may allow the wafer handling robot to continue its operation (e.g., the operation of placing a wafer on a wafer station according to the original taught position). The user may select a specified period. The specified period may be in response to a specific event, such as every time the wafer handling robot is turned on, after an error occurs in the wafer handling robot, after the planned number of pickups / placements by the wafer handling robot is completed, etc. The specified period may also be time-based, such as once a day, once a week, once a month, etc.

[0058] Also, a sensor may be used to level the roll angle of the wafer handling robot. The roll angle is the angle between the selected surface of the wafer handling robot arm 102 and the pitch axis. The pitch axis lies on the horizontal plane and is perpendicular to the roll axis described above. FIG. 7 is a flowchart for leveling the roll angle of the wafer handling robot within an acceptable level range. At block 702, the controller may move the end effector to a calibration position, i.e., a position where the roll angle of the associated wafer handling robot can be determined. At block 704, the controller may receive sensor data from a tilt sensor (e.g., a tilt sensor as described above). At block 706, the controller may determine the roll angle from the sensor data from the tilt sensor (in some implementations, such data may be adjusted considering a calibration setting that can correct for the deviation between the reference coordinate system of the tilt sensor and the reference coordinate system of the component of the wafer handling robot to which the tilt sensor is fixedly attached). At block 708, a corrective measure may be executed to bring the roll angle within an acceptable range (e.g., within an angular range similar to that described above with respect to the acceptable pitch angle range). In the embodiment shown in FIG. 1, for example, the lower mechanism 104 is the lower robot arm 120 that does not have the function of actively rotating around the roll axis. However, there may still be manually adjustable features (e.g., set screws or other fine-tuning mechanisms), and the operator may use these to eliminate or reduce such roll behavior so that the roll angle is within the acceptable range. In such an embodiment, the controller may be able to continuously feedback the roll angle to the operator so that manual adjustment can be performed. Manual adjustment may include adjustment of set screws, shim adjustment between mating parts, tightening or loosening of screws, or combinations thereof.In other embodiments, the actuator may be configured to enable rotation adjustment of the wafer handling robot (or a part thereof) around the roll axis, and the controller may control such an actuator to rotate the wafer handling robot or at least a part thereof including the tilt sensor around the roll axis so as to keep the roll angle within an allowable range.

[0059] In some implementations, the tilt sensor 216 may be calibrated to determine the orientation of the tilt sensor relative to an element of the wafer handling robot arm to which the tilt sensor 216 is fixedly attached. In an implementation where the tilt sensor is provided within the base 108, the orientation of the tilt sensor may be optionally calibrated taking into account the orientation of the tilt sensor relative to the base. The tilt sensor may be fixedly attached to the base such that a change in the pitch angle of the tilt sensor matches a change in the pitch angle of the base and a change in the roll angle of the tilt sensor matches a change in the roll angle of the base. Such a modification may be implemented by attaching the tilt sensor to the base by a more or less pre-adjusted configuration (e.g., arranging the tilt sensor such that the vertical axis of the reference coordinate system of the tilt sensor is parallel to the rotation axis of one of the wafer handling robot arm rotation joints), but there may still be some deviation. In other implementations, such pre-adjustment may not be necessary, and the tilt sensor may be placed and oriented within the base at any angle. Regardless of the manner in which the tilt sensor is attached to the base, calibration settings for the tilt sensor may be determined after attaching the tilt sensor, taking into account the deviation between the tilt sensor and a particular reference coordinate system of the base (e.g., a reference coordinate system aligned with the rotation axis of the rotary joint connecting the arm link to the base). Such calibration may be performed by placing the base on a fixture configured to arrange the reference coordinate system of the base in a particular desired orientation with respect to the earth's gravitational field (or to make the position and orientation of the base adjustable to obtain such an orientation), and obtaining the measurement values output from the tilt sensor as the orientation of the base when so arranged. Then, these measurement values (which may include one or more angle measurement values) may be used to adjust subsequent measurement values by the tilt sensor and convert those measurement values to values indicating the absolute orientation of the base (with respect to the earth's gravitational field).

[0060] In some implementation forms such as the implementation form shown in FIG. 2-2, the tilt sensor 216 may be disposed within the wafer handling robot arm link 110. When the tilt sensor 216 is fixedly attached to the wafer handling robot arm link, it may be necessary to calibrate the orientation of the tilt sensor so that it coincides with the orientation of the wafer handling robot arm link. The tilt sensor may be fixedly attached to the wafer handling robot arm link such that a change in the pitch angle of the tilt sensor coincides with a change in the pitch angle of the wafer handling robot arm link, and a change in the roll angle of the tilt sensor coincides with a change in the roll angle of the wafer handling robot arm link. Such a modification may be implemented by attaching the tilt sensor to the wafer handling robot arm by a configuration that is more or less pre-adjusted (for example, arranging the tilt sensor so that the vertical axis of the reference coordinate system of the tilt sensor is parallel to the rotation axis of one of the wafer handling robot arm joints), but there may still be some deviation. In other implementation forms, pre-adjustment may not be necessary, and the tilt sensor may be disposed and oriented within the wafer handling robot arm at an arbitrary angle. Regardless of the attachment manner of the tilt sensor to the wafer handling robot arm, calibration of the tilt sensor may be performed after the tilt sensor is attached to determine a calibration setting that takes into account the deviation between the tilt sensor and a specific reference coordinate system of the wafer handling robot arm (for example, a reference coordinate system whose axis is aligned with the rotation axis of the rotary joint connecting the arm link to the base). Such calibration techniques will be described later.

[0061] Figures 8-1 to 8-3 are diagrams showing an example of a tilt sensor 216 provided within a wafer handling robot arm link 110a. When the tilt sensor 216 is disposed within the wafer handling robot arm link 110a, the same problems as when the tilt sensor is disposed within the base may occur (for example, the reference coordinate system of the tilt sensor may not coincide with the reference coordinate system of the wafer handling robot arm link 110a). To correct such a deviation, a calibration routine may be executed to determine the orientation of the tilt sensor with respect to the orientation of the wafer handling robot arm link. FIG. 900 is a flowchart of such a calibration routine. At block 901, the controller may rotate the wafer handling robot arm link to which the sensor is fixedly attached to a first position around the axis of rotation of the rotary joint that supports the wafer handling robot arm link. At block 902, the controller may receive data from the tilt sensor. The data from the tilt sensor may be the pitch angle and roll angle acquired when the wafer handling robot arm link to which the tilt sensor is fixedly attached is in the first position. At block 904, the controller may rotate the wafer handling robot arm link to which the tilt sensor is fixedly attached to a second position around the axis of rotation of the rotary joint that supports the wafer handling robot arm link. All other parts of the wafer handling robot (or at least the part between the wafer handling robot arm link and the base 108 in the wafer handling robot) may be maintained in a stationary state such that the rotation occurring to the tilt sensor is only the rotation around this axis of rotation. For example, in FIG. 8-1, the tilt sensor 216 is fixedly attached to the wafer handling robot arm link 110a, and the controller may rotate the wafer handling robot arm link 110a around the axis 118a. In FIG. 8-1, the robot arm link is in the first position. FIG. 8-2 shows the state after the wafer handling robot arm link 110a has rotated around the axis 118a with respect to the base 108 and moved to the second position.As shown in FIGS. 8-1 and 8-2, in one embodiment, the robot arm link may rotate 180° about axis 118a relative to the base from the first position or the initial position to the second position. Returning to the flowchart of the calibration routine of FIG. 9, at block 906, the controller may receive further data from the tilt sensor. The data from the tilt sensor may be the pitch angle and the roll angle obtained when the wafer handling robot arm link is in the second position. At block 908, the controller may calibrate the tilt sensor. Using the calibration routine, the pitch and roll measurements of the tilt sensor may be converted to the coordinate system of the wafer handling robot arm link (from the reference coordinate system of the sensor to the reference coordinate system of the robot arm link). To do this, the controller may use both the pitch angle and the roll angle from the tilt sensor at the initial position and the pitch angle and the roll angle from the tilt sensor at the second position to determine the relative pitch angle and the relative roll angle of the tilt sensor with respect to the wafer handling robot arm link.

[0062] FIGS. 10-1 and 10-2 are diagrams showing an example of a wafer handling robot 100 having different reference coordinate systems and being in the first position or the second position. The different reference coordinate systems include a sensor reference coordinate system 1054, a wafer handling robot arm link reference coordinate system 1052 (“arm” reference coordinate system), and a fixed reference coordinate system 150 (“world” reference coordinate system). Using the calibration routine, the sensor reference coordinate system 1054 with respect to the wafer handling robot arm link reference coordinate system 1052 may be determined. Both the sensor reference coordinate system 1054 and the wafer handling robot arm link reference coordinate system 1052 may have an orientation with respect to the fixed reference coordinate system 150 that is unknown before calibration. The fixed reference coordinate system 150 may be oriented, for example, such that its vertical axis (z) coincides with the vertical axis with respect to the earth's gravitational field. The tilt sensor 216 can determine the pitch and roll of the sensor with respect to the fixed reference coordinate system 150.

[0063] Calibration by the controller at block 908 uses the pitch angle (θ) and roll angle (Φ) of the tilt sensor at the initial position, and the pitch angle (θ’) and roll angle (Φ’) of the tilt sensor at the second position, in combination with the amount by which the tilt sensor rotates about the axis of rotation while the arm link transitions from the initial position to the second position. In this example, the second position is a 180° rotation about the link axis of rotation 1018 from the initial position. The link axis of rotation is parallel to the Z direction of the wafer handling robot arm link reference coordinate system 1052. Both the wafer handling robot arm link reference coordinate system 1052 and the link axis of rotation 1018 may have an unknown orientation. The orientation of the link axis of rotation 1018 is a unit vector that can be represented by n1, n2, n3, which are the x, y, and z components, respectively

Number

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Number

[0064] The pitch angle and roll angle of the link reference coordinate system 1052 may be solved for the pitch (θ link ) and roll (Φ link ) of the link reference coordinate system 1052 with respect to the fixed reference coordinate system 150 according to the following relationship.

Number

[0065] Pitch offset angle (θ sensor ) and roll offset angle (Φ sensor ) of the tilt sensor with respect to the link can be obtained by solving the following equation using the initial pitch angle (θ) and roll angle (Φ) with respect to the fixed reference coordinate system 150 and the pitch angle (θ link ) and roll angle (Φ link ) of the link reference coordinate system 1052 with respect to the fixed reference coordinate system 150.

Equation

[0066] From the above description, the controller can obtain the solutions of the pitch offset angle (θ sensor ) and roll offset angle (Φ sensor ) of the tilt sensor with respect to the link reference coordinate system 1052 of the wafer handling robot arm using the following relationship.

Equation

[0067] In some implementations, the controller of the wafer handling robot may be part of an integrated system as described above. Such a system can include a semiconductor processing apparatus that includes one or more processing tools, one or more chambers, one or more processing platforms, and / or certain processing components (such as a wafer handling robot, a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of a semiconductor wafer or substrate. The electronics may also be referred to as a "controller" and may control various components or sub-components of one or more systems. The controller may be programmed to control any of the processes disclosed herein, depending on the processing requirements and / or the type of system. These processes include the supply of process gases, temperature setting (e.g., heating and / or cooling), pressure setting, vacuum setting, power setting, radio frequency (RF) generator setting, RF matching circuit setting, frequency setting, flow rate setting, fluid supply setting, position and motion setting, loading and unloading of wafers to and from tools, and loading and unloading of wafers to and from other transfer tools and / or load locks connected or coordinated with a particular system.

[0068] In a broad sense, the controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software, and performs functions such as receiving commands, sending commands, controlling operations, enabling cleaning operations, and enabling endpoint measurements. The integrated circuit may include a chip as firmware for storing program instructions, a digital signal processor (DSP), a chip defined as an application-specific integrated circuit (ASIC), and / or one or more microprocessors, or a microcontroller that executes program instructions (e.g., software). The program instructions may be instructions communicated to the controller as various individual settings (or program files), and define operating parameters for performing a specific process on or for a semiconductor wafer or for a system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to achieve one or more processing steps in the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0069] In some implementations, the controller may be part of a computer or may be coupled to a computer. Here, the computer may be integrated with the system, coupled to the system, network-connected to the system in some other way, or take a combination of these forms. For example, the controller may exist “in the cloud” or may exist in all or part of a factory host computer system. This enables remote access to wafer processing. The computer can enable remote access to the system to monitor the progress of the manufacturing process, investigate the past manufacturing process history, or investigate trends or performance metrics from multiple manufacturing processes, and can change the parameters of the current process, set the processing steps following the current process, or start a new process. In some examples, a process recipe can be provided to the system from a remote computer (e.g., a server) via a network. Here, the network may include a local network or the Internet. The remote computer may include a user interface that enables input of parameters and / or settings and programming. These parameters and / or settings are then communicated from the remote computer to the system. In some examples, the controller receives instructions as data. This data specifies the parameters for each processing step to be executed in one or more operations. It should be understood that these parameters may be specific to the type of process being executed and the type of tool that the controller is configured to cooperate with or control. Thus, as described above, the controller may be distributed, such as by comprising one or more individual controllers. These individual controllers are networked and operate towards a common purpose such as the processes and controls described herein. An example of a distributed controller for such a purpose is one or more integrated circuits mounted in a chamber that communicate with one or more integrated circuits remotely installed (e.g., at the platform level or as part of a remote computer).These integrated circuits cooperate to control the process in the chamber.

[0070] Non-limiting examples of the system include a plasma etching chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etching chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that can be associated with or used in the manufacture and / or production of semiconductor wafers.

[0071] As described above, depending on one or more process steps performed by the tool, the controller may communicate with one or more of other tool circuits or tool modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, the main computer, another controller, or tools used in the wafer container transfer for material transport to tool positions and / or load ports within the semiconductor manufacturing facility.

[0072] When phrases such as "for each of one or more <items>", "each of one or more <items>" are used in this specification, it should be understood that they include both a group consisting of a single item and a group consisting of multiple items. That is, the phrase "each~" is used in the sense that in a programming language, this phrase is used to refer to each item regardless of what the population of the items being referred to is. For example, when the population of the items being referred to is a single item, the term "each" (despite the fact that according to the dictionary definition, the term "each" is often defined as "each one of two or more things") refers only to that single item and does not mean that these items need to be at least two.

[0073] The above disclosure has been centered on specific exemplary implementations, but is not limited to only these described examples and may be applied to similar variations and mechanisms. It should be understood that such similar variations and mechanisms are also considered to be included within the scope of this disclosure. The present invention can also be realized, for example, in the following aspects. Application Example 1: An apparatus, comprising a first robotic arm, the first robotic arm having a base, one or more first robotic arm links, a tilt sensor, and a mechanism, wherein one or more of the one or more first robotic arm links are end effectors, one or more of the one or more first robotic arm links have an end rotatably connected to the base, at least one of the one or more end effectors is configured to support a semiconductor wafer, the tilt sensor is a gravity field sensor configured to detect the orientation with respect to the Earth's gravity field, the tilt sensor is fixedly attached to a component selected from the group consisting of one of the one or more first robotic arm links and the base, the mechanism supports the first robotic arm, the mechanism is configured to rotate the first robotic arm about a horizontal pitch axis in response to one or more inputs, An apparatus. Application Example 2: The apparatus of Application Example 1, wherein the mechanism includes a gimbal configured to support the base of the first robotic arm, An apparatus. Application Example 3: The apparatus of Application Example 1, wherein the mechanism is a second robotic arm, the second robotic arm having one or more second robotic arm links, one or more second robotic arm rotation joints, at least one of the one or more second robotic arm rotation joints having a horizontal rotation axis, each of the second robotic arm links is rotatably connected by one of the one or more second robotic arm rotation joints to at least one of the other second robotic arm links, the second robotic arm is configured to support the base of the first robotic arm, An apparatus. Application Example 4: The apparatus according to any one of Application Examples 1 to 3, wherein the tilt sensor is an accelerometer, An apparatus. Application Example 5: The apparatus according to any one of Application Examples 1 to 3, wherein the tilt sensor is an inclinometer, An apparatus. Application Example 6: The apparatus according to any one of Application Examples 1 to 3, wherein the tilt sensor is fixedly attached to the base, apparatus. Application Example 7: The apparatus according to any one of Application Examples 1 to 3, wherein the tilt sensor is fixedly attached to the instrumented first robot arm link among the one or more first robot arm links, apparatus. Application Example 8: The apparatus according to Application Example 7, wherein two or more first robot arm links are provided, and the instrumented first robot arm link is the first robot arm link that directly or indirectly supports each of the other one or more first robot arm links, apparatus. Application Example 9: The apparatus according to Application Example 7, wherein the instrumented first robot arm link is one of the one or more end effectors, apparatus. Application Example 10: The apparatus according to Application Example 7, wherein three or more first robot arm links are provided, the three or more first robot arm links including a proximal first robot arm link, a distal first robot arm link, and the instrumented first robot arm link, wherein the instrumented first robot arm link is rotatably connected to the proximal first robot arm link by a proximal first robot arm rotary joint at a first end, and is rotatably connected to the distal first robot arm link by a distal first robot arm rotary joint at a second end opposite to the first end, apparatus. Application Example 11: The apparatus according to Application Example 7, further including a controller including one or more processors and one or more memory devices, wherein the one or more processors and the one or more memory devices are operably connected, the one or more processors are communicably connected to the tilt sensor, the one or more memory devices store computer-executable instructions, and the computer-executable instructions, when executed by the one or more processors, cause the one or more processors to receive first sensor data generated by the tilt sensor when the instrumented first robot arm link is at a first angular position relative to the base, and rotate the instrumented first robot arm link to a second angular position relative to the base, Receiving second sensor data generated by the tilt sensor when the instrumented first robot arm link is in the second angular position; Determining calibration data of the tilt sensor based on the first sensor data and the second sensor data; and causing the execution of the above. Device. Application Example 12: The device of Application Example 11, wherein the second angular position is a position 180° from the first angular position. Device. Application Example 13: The device of Application Example 11, wherein the one or more memory devices further store additional instructions that, when executed, cause the one or more processors to move at least one of the one or more end effectors to a position associated with the wafer station; receive sensor data generated by the tilt sensor when the at least one end effector is in the position associated with the wafer station; determine a pitch angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is in the position associated with the wafer station; compare the pitch angle of the tilt sensor with a threshold pitch angle range; when the pitch angle of the tilt sensor is outside the range of the threshold pitch angle range, rotate the mechanism about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the range of the threshold pitch angle range; cause at least one of the one or more memory devices to record the taught positions of the mechanism and the first robot arm in association with the wafer station; wherein the taught position indicates the positions of the mechanism and the first robot arm when the at least one end effector is in the position associated with the wafer station and the pitch angle of the tilt sensor is within the range of the threshold pitch angle range. Device. Application Example 14: The device of Application Example 13, wherein the one or more memory devices further store additional instructions that, when executed, cause the one or more processors to take into account calibration data of the tilt sensor when determining the pitch angle. Device. Application Example 15: The device of Application Example 13, The one or more memory devices further store additional instructions, and when the additional instructions are executed, cause the one or more processors to when placing a wafer on the first robotic arm at the wafer station, move the mechanism and the first robotic arm to the taught position, device. Application Example 16: The device of Application Example 11, wherein the one or more memory devices further store additional instructions, and when the additional instructions are executed, cause the one or more processors to cause at least one of the one or more end effectors to pick up and support a wafer, move the at least one end effector and the wafer supported by the at least one end effector to a position associated with the wafer station, receive sensor data generated by the tilt sensor when the at least one end effector and the wafer supported by the at least one end effector are at the position associated with the wafer station, determine a pitch angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, when the pitch angle of the tilt sensor is outside the threshold pitch angle range, rotate the first robotic arm about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the threshold pitch angle range, after the pitch angle of the tilt sensor is within the threshold pitch angle range, move the at least one end effector to the first robotic arm and place the wafer on the wafer station, device. Application Example 17: The device of Application Example 16, wherein the one or more memory devices further store additional instructions, and when the additional instructions are executed, cause the one or more processors to when determining the pitch angle, take into account calibration data of the tilt sensor, device. Application Example 18: The device of Application Example 11, The one or more memory devices further store additional instructions, which when executed, cause the one or more processors to move at least one of the one or more end effectors to a position associated with the wafer station; receive sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; determine a pitch angle of the tilt sensor and a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; compare the pitch angle of the tilt sensor with a threshold pitch angle range; when the pitch angle of the tilt sensor is outside the threshold pitch angle range, rotate the mechanism about a first horizontal rotation axis so that the pitch angle of the tilt sensor is within the threshold pitch angle range; compare the roll angle of the tilt sensor with a threshold roll angle range; when the roll angle of the tilt sensor is outside the threshold roll angle range, rotate the mechanism about a second horizontal rotation axis so that the roll angle of the tilt sensor is within the threshold roll angle range, wherein the first and second horizontal rotation axes are both located in a horizontal plane and are orthogonal to each other; cause at least one memory device of the one or more memory devices to record the taught positions of the mechanism and the first robotic arm in association with the wafer station; wherein the taught positions indicate the positions of the mechanism and the first robotic arm when the at least one end effector is at the position associated with the wafer station, the pitch angle of the tilt sensor is within the threshold pitch angle range, and the roll angle of the tilt sensor is within the threshold roll angle range; device. Application Example 19: The device of Application Example 11, wherein the one or more memory devices further store additional instructions, which when executed, cause the one or more processors to cause at least one of the one or more end effectors to pick up and support a wafer; Moving the at least one end effector and the wafer supported by the at least one end effector to a position associated with a wafer station; Receiving sensor data generated by the tilt sensor when the at least one end effector and the wafer supported by the at least one end effector are at the position associated with the wafer station; Determining a pitch angle of the tilt sensor and a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; Comparing the pitch angle of the tilt sensor with a threshold pitch angle range; When the pitch angle of the tilt sensor is outside the range of the threshold pitch angle range, rotating the first robotic arm of the mechanism about a first horizontal rotation axis so that the pitch angle of the tilt sensor is within the range of the threshold pitch angle range; Comparing the roll angle of the tilt sensor with a threshold roll angle range; When the roll angle of the tilt sensor is outside the range of the threshold roll angle range, rotating the first robotic arm of the mechanism about a second horizontal rotation axis so that the roll angle of the tilt sensor is within the range of the threshold roll angle range, wherein both the first and second horizontal rotation axes are located in a horizontal plane and are orthogonal to each other; After the pitch angle of the tilt sensor is within the range of the threshold pitch angle range and the roll angle of the tilt sensor is within the range of the threshold roll angle range, moving the at least one end effector to the first robotic arm and placing the wafer on the wafer station; Device. Application Example 20: The device of Application Example 11, wherein the one or more memory devices further store additional instructions that, when executed, cause the one or more processors to move at least one of the one or more end effectors to a position associated with a wafer station; Receiving sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; Determining a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; Causing information indicating the roll angle of the tilt sensor to be presented; Device.

Claims

1. A wafer handling apparatus, comprising: a first robot arm, said first robot arm including: a base; a plurality of first robot arm links supported by said base; a tilt sensor configured to detect an orientation with respect to the earth's gravitational field; a mechanism for supporting said first robot arm; and one or more of said plurality of first robot arm links being end effectors, at least one of said one or more end effectors being configured to support a semiconductor wafer; one of said plurality of first robot arm links having an end rotatably connected to said base; said tilt sensor being connected to one of said plurality of first robot arm links that is not an end effector or to said base; said mechanism being configured to rotate said first robot arm about a horizontal pitch axis in response to one or more inputs. An apparatus.

2. The apparatus according to claim 1, wherein said mechanism includes a gimbal configured to support said base of said first robot arm. An apparatus.

3. The apparatus according to claim 1, wherein said mechanism is a second robot arm, said second robot arm including: one or more second robot arm links; and one or more second robot arm rotary joints, at least one of said one or more second robot arm rotary joints having a horizontal rotation axis; each of said second robot arm links being rotatably connected by one of said one or more second robot arm rotary joints to at least one of the other of said second robot arm links; said second robot arm being configured to support said base of said first robot arm. An apparatus.

4. The apparatus according to any one of claims 1 to 3, wherein said tilt sensor is an accelerometer. An apparatus.

5. The apparatus according to any one of claims 1 to 3, wherein said tilt sensor is an inclinometer. An apparatus.

6. The apparatus according to any one of claims 1 to 3, wherein said tilt sensor is fixedly attached to said base. An apparatus.

7. The apparatus according to any one of claims 1 to 3, wherein ​ The tilt sensor is fixedly attached to the instrumented first robotic arm link among the plurality of first robotic arm links. Device. **Claim 8** The device according to claim 7, wherein the instrumented first robotic arm link is the first robotic arm link that directly or indirectly supports each of the other one or more first robotic arm links. Device. **Claim 9** The device according to claim 7, wherein three or more first robotic arm links are provided, the three or more first robotic arm links including a proximal first robotic arm link, a distal first robotic arm link, and the instrumented first robotic arm link, wherein the instrumented first robotic arm link is rotatably connected to the proximal first robotic arm link by a proximal first robotic arm rotary joint at a first end, and is rotatably connected to the distal first robotic arm link by a distal first robotic arm rotary joint at a second end opposite to the first end. Device. **Claim 10** The device according to claim 7, further comprising a controller including one or more processors and one or more memory devices, wherein the one or more processors and the one or more memory devices are operably connected, the one or more processors being communicably connected to the tilt sensor, the one or more memory devices storing computer-executable instructions, which, when executed by the one or more processors, cause the one or more processors to receive first sensor data generated by the tilt sensor when the instrumented first robotic arm link is at a first angular position relative to the base, rotate the instrumented first robotic arm link to a second angular position relative to the base, receive second sensor data generated by the tilt sensor when the instrumented first robotic arm link is at the second angular position, and determine calibration data of the tilt sensor based on the first sensor data and the second sensor data. Device. **Claim 11** The device according to claim 10, The second angular position is a position 180° from the first angular position. Apparatus. **Claim 12** The apparatus according to claim 10, wherein the one or more memory devices further store additional instructions, and when the additional instructions are executed, cause the one or more processors to move at least one of the one or more end effectors to a position associated with the wafer station, receive sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, determine a pitch angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, when the pitch angle of the tilt sensor is outside the range of the threshold pitch angle range, rotate the mechanism about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the range of the threshold pitch angle range, cause at least one of the one or more memory devices to record the taught positions of the mechanism and the first robotic arm in association with the wafer station, wherein the taught positions indicate the positions of the mechanism and the first robotic arm when the at least one end effector is at the position associated with the wafer station and the pitch angle of the tilt sensor is within the range of the threshold pitch angle range. Apparatus. **Claim 13** The apparatus according to claim 12, wherein the one or more memory devices further store additional instructions, and when the additional instructions are executed, cause the one or more processors to determine the pitch angle based at least in part on calibration data from the tilt sensor. Apparatus. **Claim 14** The apparatus according to claim 12, wherein the one or more memory devices further store additional instructions, and when the additional instructions are executed by the one or more processors, cause the one or more processors to move the mechanism and the first robotic arm to the taught positions when placing a wafer on the first robotic arm at the wafer station. Device

15. The device according to claim 10, wherein the one or more memory devices further store additional instructions, and the additional instructions, when executed, cause the one or more processors to cause at least one of the one or more end effectors to pick up and support a wafer, move the at least one end effector and the wafer supported by the at least one end effector to a position associated with a wafer station, receive sensor data generated by the tilt sensor when the at least one end effector and the wafer supported by the at least one end effector are at the position associated with the wafer station, determine a pitch angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, compare the pitch angle of the tilt sensor with a threshold pitch angle range, when the pitch angle of the tilt sensor is outside the range of the threshold pitch angle range, rotate the first robotic arm about a horizontal rotation axis so that the pitch angle of the tilt sensor is within the range of the threshold pitch angle range, after the pitch angle of the tilt sensor is within the range of the threshold pitch angle range, move the at least one end effector to the first robotic arm and place the wafer on the wafer station, Device

16. The device according to claim 15, wherein the one or more memory devices further store additional instructions, and the additional instructions, when executed, cause the one or more processors to determine the pitch angle based at least in part on calibration data from the tilt sensor, Device

17. The device according to claim 10, wherein the one or more memory devices further store additional instructions, and the additional instructions, when executed, cause the one or more processors to move at least one of the one or more end effectors to a position associated with a wafer station, Receiving sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; Determining a pitch angle of the tilt sensor and a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; Comparing the pitch angle of the tilt sensor with a threshold pitch angle range; When the pitch angle of the tilt sensor is outside the range of the threshold pitch angle range, rotating the mechanism about a first horizontal rotation axis so that the pitch angle of the tilt sensor is within the range of the threshold pitch angle range; Comparing the roll angle of the tilt sensor with a threshold roll angle range; When the roll angle of the tilt sensor is outside the range of the threshold roll angle range, rotating the mechanism about a second horizontal rotation axis so that the roll angle of the tilt sensor is within the range of the threshold roll angle range, wherein both the first and second horizontal rotation axes are located in a horizontal plane and are orthogonal to each other; Causing at least one memory device of the one or more memory devices to record the teaching positions of the mechanism and the first robotic arm in association with the wafer station; The teaching position indicates the positions of the mechanism and the first robotic arm when the at least one end effector is at the position associated with the wafer station, the pitch angle of the tilt sensor is within the range of the threshold pitch angle range, and the roll angle of the tilt sensor is within the range of the threshold roll angle range. Device. **Claim 18** The device according to claim 10, wherein the one or more memory devices further store additional instructions which, when executed, cause the one or more processors to cause at least one end effector of the one or more end effectors to pick up and support a wafer; move the at least one end effector and the wafer supported by the at least one end effector to a position associated with the wafer station. When the at least one end effector and the wafer supported by the at least one end effector are at the position associated with the wafer station, receiving sensor data generated by the tilt sensor; Based on the sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station, determining a pitch angle of the tilt sensor and a roll angle of the tilt sensor; Comparing the pitch angle of the tilt sensor with a threshold pitch angle range; When the pitch angle of the tilt sensor is outside the range of the threshold pitch angle range, rotating the first robotic arm of the mechanism about a first horizontal rotation axis so that the pitch angle of the tilt sensor is within the range of the threshold pitch angle range; Comparing the roll angle of the tilt sensor with a threshold roll angle range; When the roll angle of the tilt sensor is outside the range of the threshold roll angle range, rotating the first robotic arm of the mechanism about a second horizontal rotation axis so that the roll angle of the tilt sensor is within the range of the threshold roll angle range, wherein the first and second horizontal rotation axes are both located in a horizontal plane and are orthogonal to each other; After the pitch angle of the tilt sensor is within the range of the threshold pitch angle range and the roll angle of the tilt sensor is within the range of the threshold roll angle range, moving the at least one end effector to the first robotic arm and placing the wafer on the wafer station. Device.

19. The device according to claim 10, The one or more memory devices further store additional instructions, and the additional instructions, when executed, cause the one or more processors to, Move at least one of the one or more end effectors to a position associated with the wafer station; Receive sensor data generated by the tilt sensor when the at least one end effector is at the position associated with the wafer station; Determining a roll angle of the tilt sensor based on the sensor data generated by the tilt sensor when the at least one end effector is in the position associated with the wafer station; Causing information indicating the roll angle of the tilt sensor to be presented; An apparatus.

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