Direct pick robot for multi-station semiconductor processing chambers

Abstract

This specification discloses a direct pick wafer transfer robot system that can be used to directly pick or place four wafers into or from stations of a multi-station module, such as a quad station module (QSM). The wafer transfer robot system includes two pairs of robot arms. Each pair of robot arms can be used independently of the other pair, and one pair of robot arms can be used to pick a wafer from a QSM while the other pair of robot arms supports a set of four wafers to be placed in the same QSM once the wafers have been removed from the QSM. The wafer transfer robot system can be configured to allow each wafer to be directly placed into each station of the QSM, and each such wafer placement can be individually adjustable so that each wafer can be centered on its respective target pedestal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] A PCT application is being filed contemporaneously herewith as a part of this application. Each application identified in the contemporaneously filed PCT application to which this application claims benefit or priority is hereby incorporated by reference in its entirety for all purposes. [Background technology]

[0002] Processing of semiconductor wafers for manufacturing integrated circuits and other structures typically occurs in a semiconductor processing tool that may include one or more semiconductor processing chambers. Each of the one or more semiconductor processing chambers is configured to process one or more wafers. Some semiconductor processing tools may have one or more semiconductor processing chambers that are multi-station chambers. A multi-station chamber has the ability to process multiple different wafers simultaneously, for example, at different positions within the chamber (herein, a multi-station chamber may also be referred to as a multi-station processing chamber). One particular type of multi-station chamber is the Quad Station Module (QSM), which features four wafer processing stations, each such station having a wafer receiving surface provided by a pedestal or the like. The stations in a QSM are typically arranged in a circular / square pattern. Thus, in some cases, an internal carousel, a rotary indexer system, or a wafer transport robot may be used to rotate the wafer between different stations within the QSM chamber.

[0003] FIG. 1 shows a schematic diagram of an exemplary QSM. The QSM of FIG. 1 has a process chamber 104 that includes four pedestals 106, each at a station labeled A, B, C, or D. A rotary indexer (not shown) may be disposed within the process chamber 104 and include four arms arranged in a "plus" shape that can rotate about a rotation axis centered between the four pedestals 106. A wafer on the pedestal 106 may be lifted off the pedestal 106 by lift pins (not shown) and the indexer arm may be rotated underneath. The wafer may then be lowered onto the indexer arm and the lift pins may be retracted. The indexer may then be rotated by multiples of 90° to move the wafer between the different stations. The lift pins may then be extended to lift the wafer off the indexer and the indexer may be rotated by 45° to move the indexer arm to a position between each pedestal. The wafer may then be lowered onto each pedestal 106 by lowering the lift pins.

[0004] In such a QSM, a wafer is typically placed on its initial destination pedestal indirectly by an external wafer transport robot. For example, as the arrows in FIG. 1 indicate, a wafer may be introduced into the process chamber 104 through a wafer load port associated with station A (lower left) and then moved by an indexer to any of stations B-D. Thus, all wafers introduced into the QSM of FIG. 1 will be placed directly into station A by an external wafer transport robot, but indirectly into stations B-D by the indexer. Similarly, wafers from the process chamber 104 may be removed from the process chamber 104 through station D, and thus each wafer to be picked must first be moved by the indexer to station D (if not already there) before the wafer can be retrieved by the external wafer transport robot.

[0005] 1, one external wafer transport robot (or two such robots) may simultaneously deliver two wafers, one to station A and the other to station D. Both such wafers may then be moved by an indexer to stations B and C, allowing another two wafers to be delivered to stations A and D simultaneously.

[0006] In yet another variation of the QSM, the QSM may have an indexer with four arms split into two pairs of adjacent arms. The two pairs of arms are rotatable and vertically translatable relative to each other, allowing the two pairs of arms to move vertically relative to each other and then rotate 180° relative to each other, thereby positioning the ends of one pair of arms above the ends of the other pair of arms. Thus, two indexer arms may be positioned in station A and the remaining two indexer arms may be positioned in station D, all at the same time. An external wafer transport robot may then simultaneously position four wafers in stations A and D and lower them onto the waiting indexer arms. The two pairs of arms may then be rotated relative to each other back to the "+" position and used to position wafers in and / or move wafers between stations A-D. Such indexers are discussed in further detail in U.S. Patent Application Publication No. 2018 / 0211864, which is incorporated by reference in its entirety. Summary of the Invention

[0007] Details of one or more implementations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Implementations discussed herein include, but are not limited to, at least the implementations discussed below.

[0008] In some implementations, the system includes a base, a fuselage unit pivotally connected to the base such that the fuselage unit is pivotable relative to the base about an axis of primary rotation, a pair of first robotic arms supported by the fuselage unit, and a pair of second robotic arms supported by the fuselage unit. In such implementations, each of the first robotic arms may be configured to transition between at least a first retracted state, a first near-extended state, and a first far-extended state. Further, a first distal position of each first robotic arm may be closer to the axis of primary rotation when the first robotic arm is in the first retracted state than when the first robotic arm is in the first near-extended state, and the first distal position is furthest from the axis of primary rotation when the first robotic arm is in the first far-extended state. The first distal position of each first robotic arm may be closer to the axis of primary rotation when the first robotic arm is in the first near-extended state than when the first robotic arm is in the first far-extended state. Each of the second robotic arms may be configured to transition between at least a second retracted state, a second near-extended state, and a second far-extended state. The second distal position of each second robotic arm may be closer to the axis of primary rotation when the second robotic arm is in the second retracted state than when the second robotic arm is in the second near-extended state, and the second distal position is furthest from the axis of primary rotation when the second robotic arm is in the second far-extended state. The second distal position of each second robotic arm may be closer to the axis of primary rotation when the second robotic arm is in the second near-extended state than when the second robotic arm is in the second far-extended state.

[0009] In some such implementations, each of the first robot arms may be configured to support two wafers in a top-bottom configuration, with one of the two wafers centered on a corresponding upper first location fixed relative to a portion of the first robot arm configured to support the two wafers, and the other of the two wafers centered on a corresponding lower first location fixed relative to a portion of the first robot arm configured to support the two wafers. Further, the upper first location may each be nominally centered over a different first corner of the first square region when the first robot arm is in at least one of the first near-extension state or the first far-extension state. The lower first location may each be nominally centered over a different second corner of the first square region when the first robot arm is in at least the other of the first near-extension state or the first far-extension state, with the second corner of the first square region being different from the first corner of the first square region. Each of the second robot arms is configured to support two wafers in an up-down configuration, one of the two wafers being centered on a corresponding upper second location fixed relative to a portion of the second robot arm configured to support the two wafers, and the other of the two wafers being centered on a corresponding lower second location fixed relative to a portion of the second robot arm configured to support the two wafers. The upper second locations may each be nominally centered above a different first corner of the second square region when the second robot arm is in at least one of the second near-extension state or the second far-extension state. The lower second locations may each be nominally centered above a different second corner of the second square region when the second robot arm is in at least the other of the second near-extension state or the second far-extension state, the second corner of the second square region being different from the first corner of the second square region. The first square region and the second square region may be co-located and may have the same orientation and the same size.

[0010] In some such implementations, the upper first position and the lower first position for at least one of the first robotic arms are both located along a corresponding common vertical axis. In some alternative or additional implementations, the upper first position and the lower first position for at least one of the first robotic arms may both be located along different, non-coaxial vertical axes.

[0011] In some implementations, for each first robot arm, the first robot arm may have a corresponding first end effector support arm and a plurality of corresponding first arm links. The corresponding first arm link for the first robot arm includes a corresponding first base link and one or more corresponding first intermediate arm links. Furthermore, the corresponding first base link for the first robot arm may be pivotally connected to the fuselage unit such that the corresponding first base link for the first robot arm is pivotable relative to the fuselage unit about a corresponding first axis. The corresponding first base link for the first robot arm may support one or more corresponding first intermediate arm links, and the one or more corresponding first base links for the first robot arm may support a corresponding first end effector support arm for the first robot arm. Furthermore, for each second robot arm, the second robot arm may have a corresponding second end effector support arm and a plurality of corresponding second arm links. The corresponding second arm link of the second robot arm includes a corresponding second base link and one or more corresponding second intermediate arm links. Furthermore, the corresponding second base link of the second robot arm may be pivotally connected to the fuselage unit such that the corresponding second base link of the second robot arm is pivotable relative to the fuselage unit about a corresponding second axis. The corresponding second base link of the second robot arm may support one or more corresponding second intermediate arm links, and the one or more corresponding second base links of the second robot arm may support a corresponding second end effector support arm of the second robot arm. The first axis and the second axis may all be substantially parallel to one another. The plurality of first axes may be spaced apart from one another in a direction perpendicular to the plurality of first axes. The plurality of second axes may be spaced apart from one another in a direction perpendicular to the plurality of second axes.

[0012] In some implementations, each first robotic arm may be configured to translate a corresponding first end effector support arm for the first robotic arm along a corresponding translation axis relative to the fuselage unit in response at least in part to a rotation of a first base link for the first robotic arm relative to the fuselage unit. Each second robotic arm may be configured to translate a corresponding second end effector support arm for the second robotic arm along a corresponding translation axis relative to the fuselage unit in response at least in part to a rotation of a second base link for the second robotic arm relative to the fuselage unit. The translation axes of the first robotic arm and the second robotic arm may all be substantially parallel to each other.

[0013] In some implementations, the first arm links in the plurality of corresponding first arm links for each first robot arm may be configured to rotate relative to one another about corresponding axes of rotation substantially parallel to the first axis. The first end effector support arm for each first robot arm may be configured to rotate about corresponding axes of rotation relative to a corresponding first intermediate arm link of the first robot arm that is closest to the first end effector support arm (the corresponding axes of rotation are substantially parallel to the first axis). The second arm links in the plurality of corresponding second arm links for each second robot arm may be configured to rotate relative to one another about corresponding axes of rotation substantially parallel to the second axis. The second end effector support arm for each second robot arm may be configured to rotate about corresponding axes of rotation relative to a corresponding second intermediate arm link of the second robot arm that is closest to the second end effector support arm (the corresponding axes of rotation are substantially parallel to the second axis).

[0014] In some implementations, each first robotic arm may have two corresponding first arm links, and each second robotic arm may have two corresponding second arm links.

[0015] In some such implementations, each of the first base links may have a corresponding first base link length defined by the distance between a first axis and a corresponding axis of rotation about which the corresponding first intermediate arm link is configured to rotate relative to the first base link. Each of the first intermediate arm links may have a corresponding first intermediate arm link length defined by the distance between a corresponding axis of rotation about which the first intermediate arm link is configured to rotate relative to the corresponding first base link and a corresponding axis of rotation about which the corresponding first end effector support arm is configured to rotate relative to the first intermediate arm link. Each of the second base links may have a corresponding second base link length defined by the distance between a second axis and a corresponding axis of rotation about which the corresponding second intermediate arm link is configured to rotate relative to the second base link. Each of the second intermediate arm links may have a corresponding second intermediate arm link length defined by a distance between a corresponding axis of rotation about which the second intermediate arm link is configured to rotate relative to the corresponding second base link and a corresponding axis of rotation about which the corresponding second end effector support arm is configured to rotate relative to the second intermediate arm link. The first base link length and the first intermediate arm link length for at least one of the first robotic arms may be equal to one another. The second base link length and the second intermediate arm link length for at least one of the second robotic arms may be equal to one another.

[0016] In some such implementations, a first base link length and a first intermediate arm link length for at least one of the first robotic arms can be equal to one another, a second base link length and a second intermediate arm link length for at least one of the second robotic arms can be equal to one another, and the first base link length can be longer than the second base link length.

[0017] In some implementations, a first base link length and a first mid-arm link length for at least one of the first robotic arms can be equal to each other and to a second base link length and a second mid-arm link length for at least one of the second robotic arms.

[0018] In some implementations, the first base link length and the first mid-arm link length for both of the first robotic arms can be equal, and the second base link length and the second mid-arm link length for both of the second robotic arms can be equal.

[0019] In some such implementations, the first base link length and the first mid-arm link length for both of the first robotic arms, and the second base link length and the second mid-arm link length for both of the second robotic arms may all be equal.

[0020] In some such implementations, the first base link length, the second base link length, the first intermediate arm link length, and the second intermediate arm link length for the first pair of the first robot arm and the second robot arm located on a common side of a reference plane of the fuselage unit may all be the same, and the reference plane is coplanar with the main rotation axis and disposed between both first robot arms. The first axis and the second axis of the first pair of the first robot arm and the second robot arm may be coaxial. The first base link of the first robot arm of the first pair of the first robot arm and the second robot arm may be fixed in space relative to the corresponding first inner bypass section. The first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm may be fixed in space relative to the corresponding first outer bypass section. The first inner bypass section may include a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is fixedly connected to a first base link of the first robot arm of the first pair of the first robot arm and the second robot arm. The corresponding second portion is pivotally connected to a first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the first inner bypass portion, and is positioned such that the corresponding bridge portion of the first inner bypass portion is farther from a first axis of the first robot arm of the first pair of the first robot arm and the second robot arm than a corresponding axis of rotation about which the corresponding first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm is configured to rotate relative to the first base link of the first robot arm of the first pair of the first robot arm and the second robot arm. The first outer bypass portion may include a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is pivotally connected to a first base link of a first robotic arm of a first pair of the first and second robotic arms.The corresponding second portion is fixedly connected to the first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the first outer bypass portion and is positioned such that the corresponding bridge portion of the first outer bypass portion is farther from the first axis of the first robot arm of the first pair of the first robot arm and the second robot arm than the corresponding bridge portion of the first inner bypass portion when the first robot arm of the first pair of the first robot arm and the second robot arm is in the first contracted state.

[0021] In some such implementations, the first base link length, the second base link length, the first intermediate arm link length, and the second intermediate arm link length for the second pair of the first and second robot arms located on opposite sides of the reference plane of the fuselage unit may all be the same. The first axis and the second axis of the second pair of the first and second robot arms may be coaxial. The first base link of the first robot arm of the second pair of the first and second robot arms may be fixed in space relative to the corresponding second inner bypass section. The first intermediate arm link of the first robot arm of the second pair of the first and second robot arms may be fixed in space relative to the corresponding second outer bypass section. The second inner bypass section may include a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is fixedly connected to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm. The corresponding second portion is pivotally connected to the first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the second inner bypass portion, and is positioned such that the corresponding bridge portion of the second inner bypass portion is farther from the first axis of the first robot arm of the second pair of the first robot arm and the second robot arm than the corresponding axis of rotation about which the corresponding first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm is configured to rotate relative to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm. The second outer bypass portion may include a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is pivotally connected to a first base link of a first robotic arm of a second pair of the first and second robotic arms.The corresponding second portion is fixedly connected to the first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the second outer bypass portion and is positioned such that the corresponding bridge portion of the second outer bypass portion is farther from the first axis of the first robot arm of the second pair of the first robot arm and the second robot arm than the corresponding bridge portion of the second inner bypass portion when the first robot arm of the second pair of the first robot arm and the second robot arm is in the first contracted state.

[0022] In some such implementations, the first pair of the first robotic arm and the second robotic arm and the second pair of the first robotic arm and the second robotic arm may be positioned symmetrically with respect to a reference plane.

[0023] In some implementations, the first axes can be spaced apart a different distance from the spacing between the second axes.

[0024] In some implementations, each of the first end effector support arms may have a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion. The corresponding first portion and the corresponding second portion of each of the first end effector support arms may extend along parallel axes, the parallel axes being offset from each other in a direction perpendicular to the parallel axes. The corresponding offset jog portion of each of the first end effector support arms may span between the corresponding first portion and the corresponding second portion of the first end effector support arm.

[0025] In some implementations, each of the second end effector support arms may have a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion. The corresponding first portion and the corresponding second portion of each of the second end effector support arms may extend along parallel axes, the parallel axes being offset from each other in a direction perpendicular to the parallel axes. The corresponding offset jog portion of each of the second end effector support arms may span between the corresponding first portion and the corresponding second portion of the second end effector support arm.

[0026] In some implementations, the base may be fixedly mounted relative to the transfer chamber. The torso unit may be at least partially located within the transfer chamber. The first robotic arm may be fully located within the transfer chamber when in the first retracted state. The second robotic arm may be fully located within the transfer chamber when in the second retracted state. The torso unit may be rotatable within the transfer chamber together with the first robotic arm and the second robotic arm at least 90° relative to the transfer chamber when the first robotic arm is in the first retracted state and the second robotic arm is in the second retracted state.

[0027] In some implementations, the system may further include one or more multi-station processing chambers. Each multi-station processing chamber may be connected to the transfer chamber by one or more corresponding wafer transfer paths. Each multi-station processing chamber may have a corresponding pair of near pedestals close to the transfer chamber and a corresponding pair of far pedestals far from the transfer chamber. The first robot arm may be configured to transfer a wafer to the corresponding pair of near pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the first robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the first robot arm is in a first near extension state. The first robot arm may be configured to transfer a wafer to the corresponding pair of far pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the first robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the first robot arm is in a first far extension state. The second robot arm may be configured to transfer the wafer to the corresponding pair of near pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the second robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the second robot arm is in the second near-extended state. The second robot arm may be configured to transfer the wafer to the corresponding pair of far pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the second robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the second robot arm is in the second far-extended state.

[0028] In some such implementations, each multi-station processing chamber may be a quad-station module.

[0029] In some implementations, the system may further include one or more active wafer centering sensor systems, each configured to obtain a center position measurement of a wafer transported by the first robot arm and / or the second robot arm through one of the wafer transport paths.

[0030] In some implementations, the system may further include a controller including one or more memory devices and one or more processors for storing computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to a) transition the first robot arm from a first retracted state to a first far-extended state with each first robot arm supporting a pair of wafers; b) leaving the first robot arm in the first far-extended state while a lower wafer supported by the first robot arm is lifted from the first robot arm; c) transition the first robot arm from the first far-extended state to a first near-extended state after (b) and while each first robot arm supports a wafer of the pair of wafers supported by the first robot arm that was not removed in (b); d) leaving the first robot arm in the first near-extended state while an upper wafer supported by the first robot arm is lifted from the first robot arm; and e) transition the first robot arm from the first near-extended state to a first retracted state after (d) and while each first robot arm is not supporting a wafer.

[0031] In some such implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, sequentially cause the one or more processors to: rotate the torso unit, extend or retract at least one of the first robot arms, or rotate the torso unit and extend or retract at least one of the first robot arms to center one of the wafers lifted from the first robot arm during (b) on a first far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the first robot arms, or rotate the torso unit and extend or retract at least the other of the first robot arms to center the other of the wafers lifted from the first robot arm during (b) on a second far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b).

[0032] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust by one of the first robot arms its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center one of the wafers lifted from the first robot arms during (b) on a first far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b), and cause the other of the first robot arms to adjust its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center the other of the wafers lifted from the first robot arms during (b) on a second far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b).

[0033] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust an amount of extension by one of the first robot arms, an amount of rotation relative to the torso unit, or an amount of extension and an amount of rotation relative to the torso unit to center one of the wafers lifted from the first robot arm during (b) over a first far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the first robot arms, or rotate the torso unit and extend or retract at least the other of the first robot arms, to center the other of the wafers lifted from the first robot arm during (b) over a second far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b).

[0034] In some implementations, the one or more memory devices may further store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to: f) transition the first robot arms from the first retracted state to a first near extended state while each of the first robot arms is not supporting a wafer; g) leave the first robot arms in the first near extended state while each of the first robot arms has a corresponding wafer disposed thereon; h) transition the first robot arms from the first near extended state to a first far extended state after (g) and while each of the first robot arms supports a single wafer disposed thereon in (g); i) leave the first robot arms in the first far extended state while each of the first robot arms has another wafer disposed thereon and in a position below the wafer already supported by the first robot arm; and j) transition the first robot arms from the first far extended state to a first retracted state after (i) and while each of the first robot arms supports two wafers disposed thereon.

[0035] In some implementations, the one or more memory devices may further store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to 1) transition the second robot arm from the second retracted state to a second far-extended state with each second robot arm supporting a pair of wafers; 2) leave the second robot arm in the second far-extended state while a lower wafer supported by the second robot arm is lifted from the second robot arm; 3) transition the second robot arm from the second far-extended state to a second near-extended state after (2) and while each second robot arm supports a wafer of the pair of wafers supported by the second robot arm that was not removed in (2); 4) leave the second robot arm in the second near-extended state while an upper wafer supported by the second robot arm is lifted from the second robot arm; and 5) transition the second robot arm from the second near-extended state to a second retracted length state after (4) and while each second robot arm is not supporting a wafer.

[0036] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, sequentially cause the one or more processors to: rotate the torso unit, extend or retract at least one of the second robot arms, or rotate the torso unit and extend or retract at least one of the second robot arms to center one of the wafers lifted from the second robot arm during (2) on a first far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2), and rotate the torso unit, extend or retract at least the other of the second robot arms, or rotate the torso unit and extend or retract at least the other of the second robot arms, to center the other of the wafers lifted from the second robot arm during (2) on a second far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0037] The one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust by one of the second robot arms its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center one of the wafers lifted from the second robot arms during (2) on a first far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2), and cause the other of the second robot arms to adjust its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center the other of the wafers lifted from the second robot arms during (2) on a second far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0038] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust an amount of extension by one of the second robot arms, an amount of rotation relative to the torso unit, or an amount of extension and an amount of rotation relative to the torso unit to center one of the wafers lifted from the second robot arm during (2) on a first far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2), and rotate the torso unit, extend or retract at least the other of the second robot arms, or rotate the torso unit and extend or retract at least the other of the second robot arms, to center the other of the wafers lifted from the second robot arm during (2) on a second far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0039] In some implementations, the one or more memory devices may further store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to: 6) transition the second robot arms from the second retracted state to a second near extended state while each second robot arm is not supporting a wafer; 7) leave the second robot arms in the second near extended state while each second robot arm has a corresponding wafer disposed thereon; 8) transition the second robot arms from the second near extended state to a second far extended state after (g) and while each second robot arm supports a single wafer disposed thereon in (g); 9) leave the second robot arms in the second far extended state while each second robot arm has another wafer disposed thereon and in a position below the wafer already supported by the second robot arm; and 10) transition the second robot arms from the second far extended state to a second retracted state after (9) and while each second robot arm supports two wafers disposed thereon.

[0040] In some implementations, a system may be provided that includes a base, a fuselage unit pivotally connected to the base such that the fuselage unit is pivotable relative to the base about an axis of primary rotation, and a pair of robotic arms supported by the fuselage unit. Each of the robotic arms may be configured to transition between at least a retracted state, a near extension state, and a far extension state. A distal position of each robotic arm may be closer to the axis of primary rotation when the robotic arm is in the retracted state than when the robotic arm is in the near extension state, and the distal position may be furthest from the axis of primary rotation when the robotic arm is in the far extension state. A distal position of each robotic arm may be closer to the axis of primary rotation when the robotic arm is in the near extension state than when the robotic arm is in the far extension state.

[0041] In some such implementations, each of the robot arms may be configured to support two wafers in a top-bottom configuration, with one of the two wafers centered on a corresponding upper location fixed relative to a portion of the robot arm configured to support the two wafers, and the other of the two wafers centered on a corresponding lower location fixed relative to a portion of the robot arm configured to support the two wafers. The upper locations may each be nominally centered above a different first corner of the square region when the robot arm is in at least one of a near extension state or a far extension state. The lower locations may each be nominally centered above a different second corner of the square region when the robot arm is in at least the other of the near extension state or a far extension state, with the second corner of the square region being different from the first corner of the square region.

[0042] In some implementations, the upper and lower positions for at least one of the robotic arms may both lie along a corresponding common vertical axis, hi some other or additional implementations, the upper and lower positions for at least one of the robotic arms may both lie along different, non-coaxial vertical axes.

[0043] In some implementations, for each robot arm, the robot arm may have a corresponding end effector support arm and a plurality of corresponding arm links. The corresponding arm links for the robot arm include a corresponding base link and one or more corresponding intermediate arm links. The corresponding base links for the robot arm may be pivotally connected to the fuselage unit such that the corresponding base links for the robot arm are pivotable relative to the fuselage unit about a corresponding first axis. The corresponding base links for the robot arm may support one or more corresponding intermediate arm links, and the one or more corresponding base links for the robot arm may support a corresponding end effector support arm for the robot arm. In such implementations, the first axes may be substantially parallel to one another and may be spaced apart from one another in a direction perpendicular to the first axis.

[0044] In some implementations, each robotic arm may be configured to translate a corresponding end effector support arm for the robotic arm along a corresponding translation axis relative to the fuselage unit in response at least in part to a rotation of the base link for the robotic arm relative to the fuselage unit. The translation axes of the robotic arms may be substantially parallel to one another.

[0045] In some implementations, the arm links in the plurality of corresponding arm links for each of the robot arms may be configured to rotate relative to one another about corresponding axes of rotation that are substantially parallel to the first axis. The end effector support arm for each of the robot arms may be configured to rotate about a corresponding axis of rotation relative to a corresponding intermediate arm link of the robot arm that is closest to the end effector support arm (the corresponding axis of rotation being substantially parallel to the first axis).

[0046] In some implementations, each robotic arm may have two corresponding arm links.

[0047] In some implementations, each of the base links may have a corresponding base link length defined by the distance between the first axis and a corresponding axis of rotation about which the corresponding intermediate arm link is configured to rotate relative to the base link. Each of the intermediate arm links may have a corresponding intermediate arm link length defined by the distance between a corresponding axis of rotation about which the intermediate arm link is configured to rotate relative to the corresponding base link and a corresponding axis of rotation about which the corresponding end effector support arm is configured to rotate relative to the intermediate arm link. The base link length and the intermediate arm link length may be equal to one another.

[0048] In some implementations, the robot arm may be positioned symmetrically with respect to a reference plane.

[0049] In some implementations, each of the end effector support arms may have a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion. The corresponding first portion and the corresponding second portion of each of the end effector support arms may extend along parallel axes that are offset from each other perpendicularly relative to the parallel axes. The corresponding offset jog portion of each of the end effector support arms may span between the corresponding first portion and the corresponding second portion of the end effector support arm.

[0050] In some implementations, the system may further comprise a transfer chamber. The base may be fixedly mounted relative to the transfer chamber. The fuselage unit may be at least partially located within the transfer chamber. The robot arm may be located completely within the transfer chamber when in the retracted state. The fuselage unit may be rotatable within the transfer chamber together with the robot arm by at least 90° relative to the transfer chamber when the robot arm is in the retracted state.

[0051] In some implementations, the system may further include one or more multi-station processing chambers. Each multi-station processing chamber may be connected to the transfer chamber by one or more corresponding wafer transfer paths. Each multi-station processing chamber may have a corresponding pair of near pedestals close to the transfer chamber and a corresponding pair of far pedestals far from the transfer chamber. The robot arm may be configured to transfer a wafer to the corresponding pair of near pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the robot arm is in a near extension state. The robot arm may be configured to transfer a wafer to the corresponding pair of far pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the robot arm is in a far extension state.

[0052] In some such implementations, each multi-station processing chamber may be a quad-station module.

[0053] In some implementations, the system may further include one or more active wafer centering sensor systems, each configured to obtain a center position measurement of a wafer transported by the robotic arm through one of the wafer transport paths.

[0054] In some implementations, the system may further include a controller including one or more memory devices and one or more processors. The one or more memory devices store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to: a) transition the robot arms from a retracted state to a far-extended state with each robot arm supporting a pair of wafers; b) leave the robot arms in the far-extended state while a lower wafer supported by the robot arms is lifted from the robot arms; c) transition the robot arms from the far-extended state to a near-extended state after (b) and with each robot arm supporting a wafer of the pair of wafers supported by the robot arms that was not removed in (b); d) leave the robot arms in the near-extended state while an upper wafer supported by the robot arm is lifted from the robot arms; and e) transition the robot arms from the near-extended state to a retracted state after (d) and with each robot arm not supporting a wafer.

[0055] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to sequentially rotate the torso unit, extend or retract at least one of the robot arms, or rotate the torso unit and extend or retract at least one of the robot arms to center one of the wafers lifted from the robot arms during (b) over a first far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the robot arms, or rotate the torso unit and extend or retract at least the other of the robot arms, to center the other of the wafers lifted from the robot arms during (b) over a second far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b).

[0056] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust by one of the robot arms its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center one of the wafers lifted from the robot arms during (b) over a first far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b), and cause the other of the robot arms to adjust its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center the other of the wafers lifted from the robot arms during (b) over a second far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b).

[0057] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust by one of the robot arms an amount of extension thereof, an amount of rotation thereof relative to the torso unit, or an amount of extension thereof and an amount of rotation thereof relative to the torso unit to center one of the wafers lifted from the robot arms during (b) on a first far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the robot arms, or rotate the torso unit and extend or retract at least the other of the robot arms, to center the other of the wafers lifted from the robot arms during (b) on a second far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b).

[0058] In some implementations, the one or more memory devices may further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to: f) transition the robot arms from a retracted state to a near-extended state with each robot arm not supporting a wafer, g) leave the robot arms in the near-extended state while each of the robot arms has a corresponding wafer disposed thereon, h) transition the robot arms from a near-extended state to a far-extended state after (g) and with each robot arm supporting a single wafer disposed thereon in (g), i) leave the robot arms in a far-extended state while each of the robot arms has another wafer disposed thereon and in a position below the wafer already supported by the robot arm, and j) transition the robot arms from a far-extended state to a retracted state after (i) and with each robot arm supporting two wafers disposed thereon.

[0059] In addition to the implementations listed above, other implementations apparent from the following discussion and drawings should all be understood to be within the scope of the present disclosure. [Brief description of the drawings]

[0060] In the following discussion, reference will be made to the following drawings, which are not intended to be limiting in scope, but are provided solely to facilitate the following discussion:

[0061] [Figure 1] FIG. 1 shows a schematic diagram of an exemplary QSM.

[0062] [Diagram 2] FIG. 2 shows an overhead view of a semiconductor processing tool featuring a transfer chamber that is connected to three different processing chambers on three sides. [Diagram 3] FIG. 3 shows an overhead view of a semiconductor processing tool featuring a transfer chamber that is connected on three sides to three different processing chambers. [Figure 4] FIG. 4 shows an overhead view of a semiconductor processing tool featuring a transfer chamber that is connected to three different processing chambers on three sides.

[0063] [Diagram 5] FIG. 5 shows an exemplary robotic arm system in various extension states. [Figure 6] FIG. 6 shows an exemplary robotic arm system in various extension states. [Figure 7] FIG. 7 shows an exemplary robotic arm system in various extension states.

[0064] [Figure 8] FIG. 8 shows an isometric view of the transfer chamber and QSM along with a robotic arm system having horizontally offset upper and lower wafer support positions.

[0065] [Figure 9]FIG. 9 shows the same transfer chamber and QSM as FIG. 8, with the two wafers on the left raised from the end effectors that support them, exposing the end effectors.

[0066] [Figure 10] FIG. 10 shows a top view of two horizontally offset wafers just before they pass through the wafer load slot.

[0067] [Figure 11] FIG. 11 shows an enlarged detailed view of an exemplary end effector configured to carry two wafers in a horizontally offset, one above the other configuration.

[0068] [Figure 12] FIG. 12 shows an enlarged detailed view of an exemplary end effector configured to carry two wafers in a horizontally aligned, one-above-the other configuration.

[0069] [Figure 13] FIG. 13 shows a front view of the robot arm system of FIG. [Figure 14] FIG. 14 shows a side view of the robot arm system of FIG.

[0070] [Figure 15] FIG. 15 shows an isometric view of the robot arm system of FIG. [Figure 16] FIG. 16 shows an isometric view of the robot arm system of FIG.

[0071] [Figure 17] FIG. 17 shows a cross-sectional schematic of an exemplary robotic arm system.

[0072] [Figure 18] FIG. 18 shows another cross-sectional schematic view of another exemplary robotic arm system.

[0073] [Figure 19]FIG. 19 shows a plan view of a robotic arm system similar to that shown in FIG.

[0074] [Figure 20] FIG. 20 shows a top view of an example robotic arm system including a first robotic arm and a second robotic arm, where the first axis is not coaxial with the second axis.

[0075] [Figure 21] FIG. 21 shows a top view of another example robotic arm system that includes a first robotic arm and a second robotic arm, where the first axis is coaxial with the second axis, but the lengths of the first robotic arm and the second robotic arm are not equal.

[0076] [Figure 22] FIG. 22 shows a schematic diagram of an optical sensor for an active wafer centering (AWC) system that may be used to obtain individual wafer center measurements relative to an end effector in a configuration where two wafers are supported in a stacked arrangement.

[0077] [Figure 23] FIG. 23 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 24] FIG. 24 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 25] FIG. 25 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 26] FIG. 26 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 27]FIG. 27 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 28] FIG. 28 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 29] FIG. 29 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 30] FIG. 30 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 31] FIG. 31 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of a robotic arm system operation. [Diagram 32] FIG. 32 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 33] FIG. 33 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 34] FIG. 34 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of robotic arm system operation. [Diagram 35] FIG. 35 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 36] FIG. 36 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 37] FIG. 37 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 38] FIG. 38 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Figure 39] FIG. 39 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 40] FIG. 40 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 41] FIG. 41 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of a robotic arm system operation. [Diagram 42] FIG. 42 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 43] FIG. 43 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation. [Diagram 44] FIG. 44 shows isometric views of an exemplary semiconductor processing tool including a transfer chamber and a processing chamber at different stages of the robotic arm system operation.

[0078] [Diagram 45] FIG. 45 shows an isometric view of an exemplary robotic arm system having a single pair of robotic arms.

[0079] [Diagram 46] FIG. 46 shows a cross-sectional schematic diagram of an exemplary robotic arm system having a single pair of robotic arms.

[0080] [Figure 47] FIG. 47 shows another cross-sectional schematic view of another example robotic arm system having a single pair of robotic arms.

[0081] [Figure 48] FIG. 48 shows a plan view of a robotic arm system similar to that shown in FIG.

[0082] [Figure 49] FIG. 49 shows two top views of an exemplary robotic arm system within the transfer chamber adjacent to the QSM.

[0083] The above-mentioned drawings are provided to facilitate understanding of the concepts discussed in this disclosure and are intended to be illustrative of certain implementations within the scope of this disclosure, but are not intended to be limiting; implementations consistent with this disclosure and not shown are also deemed to be within the scope of this disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0084] This specification discloses a new wafer-transfer robot system that allows multiple (e.g., four) wafers to be directly placed in different stations of a multi-station processing chamber, such as a Quad Station Module (QSM). In some implementations, the wafer-transfer robot system provides two pairs of robot arms, each pair of robot arms mounted on a common torso unit that is rotatable relative to the multi-station chamber. Each robot arm in the two pairs of robot arms can transition between three states (retracted, near-extended, and far-extended) relative to the torso unit. When all of the robot arms of the wafer-transfer robot system are in their respective retracted states, the torso unit can be rotatable, for example, within a transfer chamber. The transfer chamber can accommodate the wafer-transfer robot system without the wafer-transfer robot or the wafers supported thereon colliding with the transfer chamber (or other equipment). In some additional implementations of the wafer-transfer robot system, only a single pair of opposing robot arms can be mounted on the common torso unit. Such a wafer transport robot system may have reduced throughput capacity compared to implementations that include two pairs of robot arms, but may be less costly and in certain circumstances may not actually result in any throughput penalty.

[0085] The transfer chamber may be directly or indirectly connected to one or more processing chambers (e.g., QSMs, load locks or load ports that may receive and / or deliver wafers to a wafer transport robotic system). For example, in a generally square transfer chamber, each of three of the sides of the transfer chamber may be connected to a different processing chamber. Each processing chamber is a QSM. The fourth side of the transfer chamber may be connected to, for example, a load lock or another chamber or chambers from which the wafer may initially be delivered to the transfer chamber or from which it may be removed. The torso unit may be nominally rotatable to each of four different rotational positions. Each rotational position allows a robot arm mounted on the torso unit to extend into (and later retract from) a corresponding one of the different processing chambers or one or more other chambers. In the case of multi-station chambers such as those found in QSMs, the stations and pedestals therein may be arranged in a circular or square pattern. Two of the stations and / or pedestals are located closer to the transfer chamber than the remaining two stations and / or pedestals. The two pedestals or stations of the QSM that are closer to the transfer chamber may be referred to herein as the "near" pedestals or stations, while the two pedestals or stations that are farther from the transfer chamber may be referred to herein as the "far" pedestals or stations.

[0086] When the torso unit is rotated into alignment with one of the processing chambers, the robot arm of the wafer transport robot system may be positioned, for example, such that the robot arm can be transitioned to a near-extended state or a far-extended state without colliding with the walls of the processing or transfer chamber.

[0087] 2-4 show an overhead view of a semiconductor processing tool featuring a transfer chamber 202 connected to three different processing chambers 204 on three sides (processing chambers 204 and transfer chamber 202 are shown with gaps between them, but in reality such chambers are adjacent to each other or other devices (e.g., slit valves that allow processing chambers 204 to be isolated from transfer chamber 202) fill the gap). Each processing chamber 204 is a four-station QSM, with each station having a corresponding pedestal 206. As shown, in the middle of the transfer chamber 202 is located a wafer transport robot system 208 having a torso unit 212. The torso unit 212 can rotate about an axis to face the center processing chamber (FIG. 2), the left processing chamber (FIG. 3), or the right processing chamber (FIG. 4).

[0088] 5-7 illustrate an exemplary robotic arm system 508 in various extension states. The illustrated exemplary robotic arm system 508 is a system having two pairs of robotic arms. FIG. 5 illustrates the robotic arm system 508 with both pairs of robotic arms, the first 520a and the second 520b, in a retracted state. FIG. 6 illustrates the robotic arm system 508 with the first pair of robotic arms 520a in a retracted state and the second pair of robotic arms 520b in a near-extended state. FIG. 7 illustrates the robotic arm system 508 with the first pair of robotic arms 520a in a far-extended state and the second pair of robotic arms 520b in a retracted state. It will be appreciated that both pairs of robotic arms, the first and second, may transition between all three states.

[0089] 5-7 also show a square region 572 having a corner nominally coinciding with the center point of the pedestal 506 (or a target point on which the wafer 516 is nominally centered on such a pedestal 506), as may be the case for a multi-station chamber that is, for example, a QSM. The target point may also be referred to as a target position, and may be divided into a near target point or position (for a near pedestal 506) and a far target point or position (for a far pedestal 506).

[0090] Each of the first robot arm 520a and the second robot arm 520b may have a portion, for example a first end effector 540a and a second end effector 540b, respectively, configured to support a pair of wafers 516 during wafer transfer. Each such portion of the first robot arm 520a and the second robot arm 520b may have a corresponding first position 524a or second position 524b associated therewith, which corresponds to a position at which a wafer placed thereon is nominally centered. The first position 524a and the second position 524b are fixed in space relative to the corresponding portion of the associated first robot arm 520a and the second robot arm 520b, respectively. It will be understood that each first position 524a may be considered to include both an upper first position 524a and a lower first position 524a. The upper first position 524a represents a position above which the upper wafer 516 supported by the first end effector 540a is nominally centered during transfer of the wafer by the first end effector 540a. The lower first position 524a represents a position above which the lower or bottom wafer 516 supported by the first end effector 540a is nominally centered during transfer of the wafer by the first end effector 540a. In the illustrated implementation, the upper and lower first positions 524a are centered with respect to one another when viewed from above. However, in other implementations, for example, where the wafer 516 is carried in a horizontally displaced or offset top-bottom configuration, the upper and lower first positions 524a may not be centered with respect to one another when viewed from above, such as the vertical axes passing through the upper and lower first positions 524a may not be coaxial with one another.

[0091] FIG. 8 shows an isometric view of the transfer chamber and QSM with a robot arm system having horizontally offset upper and lower wafer support positions. FIG. 9 shows the same transfer chamber and QSM with the two leftmost wafers raised from the end effectors supporting them to expose the end effectors. As seen in FIG. 8, a process chamber 804 and a transfer chamber 802 are shown. A robot arm system similar to that described above with respect to FIGS. 5-7 may be housed within the transfer chamber 802 and controlled to transfer wafers 816 into and out of the process chamber 804. In FIG. 9, the leftmost wafer 816 supported by the robot arm system has been moved upward to expose the end effectors 840a and 840b.

[0092] As seen in the schematic diagram of FIG. 10, the schematic diagram shows a top view of two horizontally offset wafers just before passing through a wafer load slot 1074 of a process chamber 1004 (which may be a QSM or other multi-station chamber). The wafer load slot may include or be located near an optical sensor of an AWC system. In FIG. 10, the two x's 1088 and 1090 each represent the location of an optical beam emitter and receiver pair of the AWC system. The optical emitter 1088 and optical receiver 1090 may be configured to detect when an object such as a wafer interrupts a vertically oriented line of sight of the optical receiver 1090 (for purposes of FIG. 10, such vertical line of sight may be understood to be perpendicular to the page).

[0093] The horizontal offset of the wafers on the end effector allows the wafers 1016a and 1016b to pass through the wafer load slot 1074 such that the edges of the wafers 1016a and 1016b cross the vertical line of sight of two separate sets of optical receivers, but in so doing, the intersections of the edges and optical lines of sight for both wafers 1016a and 1016b are not mixed with the intersections of the other wafer 1016a or 1016b. With such an arrangement (as opposed to that discussed with respect to FIG. 34 ), a single beam optical sensor of the AWC system may be used to sequentially obtain center position measurements for both wafers supported by the end effector. This is because such a beam sensor may be spaced such that four points along the edge of the leading wafer may cross the beam sensor before four points along the edge of the trailing wafer, thus allowing the center of each wafer to be determined without concern as to which wafer edge will trip the AWC sensor. The center position so measured may then be used by the AWC to guide the centering of each wafer on its respective pedestal or wafer support within the chamber.

[0094] 11 shows an enlarged detailed view of an exemplary end effector configured to carry two wafers in a horizontally offset, one above the other configuration. The exemplary end effector 1140 includes a base 1135 from which extend two sets of blades 1141a and 1141b. The base 1135 may be supported by an end effector support arm 1128. The tips 1137a and 1137b of each of the blades 1141a and 1141b may be positioned at different distances from the base 1135. Both sets of blades 1141a and 1141b may feature multiple contact pads 1139 or similar features that may act as contact locations to support a wafer supported by the end effector. As will be apparent, one of the contact pads 1139 for the upper side of the end effector 1140 is located on the base 1135, thus allowing the wafer supported by the upper side to be positioned at least partially above the base 1135. This allows blade 1141a (the upper blade) to extend much less from the base 1135 than blade 1141b, thus providing the horizontal offset discussed above.

[0095] FIG. 12 shows an enlarged detailed view of an exemplary end effector configured to carry two wafers in a horizontally aligned top-bottom configuration (similar to that depicted in FIGS. 5-7). The exemplary end effector 1240 includes a base (in this case provided by the end effector support arm 1228) from which extend two sets of blades 1241a and 1241b. The tips 1237a and 1237b of each of the blades 1241a and 1241b may be positioned approximately the same distance from the base 1235 (although not necessarily, both sets of blades may be configured to support a wafer at the same horizontal location such that the wafer is horizontally aligned). Both sets of blades 1241a and 1241b may feature multiple contact pads 1239 or similar features that may act as contact locations for supporting a wafer supported by the end effector. This configuration allows blades 1241a and 1241b to simultaneously support wafers in a horizontally aligned top-bottom configuration.

[0096] Returning to Figures 5-7, it will be further understood that each second position may include both the upper second position 524b and the lower second position 524b as well. The upper second position 524b and the lower second position 524b may be similar to the upper first position 524a and the lower first position 524a. In view of the fact that each first end effector 540a in this example (and later examples discussed herein) has upper and lower first positions 524a whose centers coincide with each other when viewed from above, and the fact that each second end effector 540b in this example (and later examples discussed herein) has upper and lower second positions 524b whose centers coincide with each other when viewed from above, the first position 524a will be referred to simply as the first position 524a without any special distinction between its upper and lower instances. Similarly, the second position 524b will be referred to simply as the second position 524b, without any special distinction as to its upper and lower instances.

[0097] 5-7, a pair of wafers 516 is shown supported on a first end effector 540a of a first robot arm 520a on the left, and another pair of wafers 516 is shown supported on a second end effector 540b of a second robot arm 520b on the right, for illustrative purposes only to show the associated extension states with each robot arm in a wafer-loaded state and a wafer-unloaded state in each of the near and far extension states shown in FIGS.

[0098] Each first end effector 540a and each second end effector 540b may have a corresponding first position 524a and second position 524b, respectively. The first position 524a and second position 524b are fixed with respect to the first end effector 540a or the second end effector 540b, respectively, and are nominally centered above or below one or more wafers 516 supported on the first end effector 540a or the second end effector 540b when the first end effector 540a or the second end effector 540b is used to transfer wafers 516 during normal use. In other words, the corresponding first position 524a for each first end effector 540a is a nominal target point above or below which the wafer 516 transferred by the first end effector 540a is centered. It will be appreciated that such first location 524a need not necessarily correspond to any physically observable feature on the first end effector 540a, and in some cases may actually be located so as not to overlap the first end effector 540a at all (e.g., some blade-type end effectors as shown may be flat with a large V-shaped cutout at one end, and a portion near the end of the V is designed to support a wafer such that the wafer is centered above / in the inside of the V-cutout, i.e., at a location that does not actually overlap any member of the end effector when viewed from above). The second location 524b may be similarly located for the second end effector 540b.

[0099] As described above, each of the first robotic arm 520a and the second robotic arm 520b is configured to be actuated to be capable of transitioning between at least three different states. Examples of the at least three different states are respectively represented by Figures 5-7.

[0100] When either the first robotic arm 520a or the second robotic arm 520b is in its corresponding far-extended state (see FIG. 7), there is a corresponding distal position on that robotic arm that is furthest from the axis of rotation 514 (also referred to herein as the primary axis of rotation or axis of primary rotation) of the robotic arm system 508. Thus, the first robotic arm 520a may have a first distal position 522a, and the second robotic arm 520b may have a second distal position 522b.

[0101] When the first robotic arm 520a or the second robotic arm 520b is in the retracted state, the first distal position 522a or the second distal position 522b, respectively, may be closer to the axis of rotation 514 than when the first robotic arm 520a or the second robotic arm 520b is in the near-extended state or the far-extended state. Similarly, when the first robotic arm 520a or the second robotic arm 520b is in the near-extended state, the first distal position 522a or the second distal position 522b, respectively, may be closer to the axis of rotation 514 than when the first robotic arm 520a or the second robotic arm 520b is in the far-extended state.

[0102] In the near extension state shown in FIG. 6 for the second robot arm 520b, the second end effector 540b of the second robot arm 320b is positioned such that the corresponding second position 524b is located directly above a target position (e.g., one of the corners of the square area 572, which is on one of the "near" pedestals 506 on which the wafer is placed). The second position 524b is fixed in space relative to the second end effector 540b and is generally aligned (when viewed from above) with the center point of the wafer 516 that is supported or will be supported by the second end effector 540b. Such a target position is often the nominal center point of the near pedestal. Similar rules apply to each first robot arm.

[0103] Similarly, in the far extension state shown in FIG. 7 for the first robot arm 520a, the first end effector 540a of the first robot arm 520a is positioned such that the corresponding first position 524a is located directly above a target position (e.g., one of the corners of the square area 572, which is on one of the "far" pedestals 506 where the wafer is placed). The first position 524a is fixed in space relative to the first end effector 540a and generally aligns (when viewed from above) with the center point of the wafer 516 that is supported or will be supported by the first end effector 540a. Such a target position is often the nominal center point of the near pedestal. Similar rules apply to each second robot arm.

[0104] In some implementations, the first robot arm 520a and / or the second robot arm 520b may be configured to allow the first position 524a and the second position 524b to extend inward or outward along the translation axis 566. In some such implementations, the first robot arm 520a and / or the second robot arm 520b may each be a one degree of freedom robot arm that is kinematically configured to allow the first end effector 540a and / or the second end effector 540b, respectively, to be extendable only along the translation axis. The translation axis may be fixed in space relative to the fuselage unit 512, and thus such first robot arm 520a and / or such second robot arm 520b may be limited to affecting translational wafer motion relative to the fuselage unit 512, although the fuselage unit 512 may also be rotated to rotate the first robot arm 520a and / or the second robot arm 520b. In other implementations, however, as described later herein, each of the first robotic arm 520a and / or the second robotic arm 520b may be a two-degree-of-freedom robotic arm that is kinematically configured to enable each of the first end effector 540a and / or the second end effector 540b to extend along a translational axis and to enable the first robotic arm 520a and / or the second robotic arm 520b to rotate relative to the torso unit 512.

[0105] In the implementation illustrated in Figures 5 to 7, the first robot arm 520a and the second robot arm 520b are both of the Selectively Compliant Assembly Robot Arm (or SCARAs) type, each with one degree of freedom. In the illustrated configuration, the first robot arm 520a and the second robot arm 520b are "nested", with the second robot arm 520b fitting completely between the portions of the first robot arm 520a. Thus, when the first robot arm 520a is in a retracted state, the second robot arm 520b can be extended or retracted without colliding with the first robot arm 520a (even though the second robot arm 520b may completely overlap the first robot arm 520a when the robot arm system is viewed from above with the first robot arm 520a and the second robot arm 520b in a retracted state). The first robotic arm 520a may similarly be extendable and retractable without colliding with the second robotic arm 520b when the second robotic arm 520b is in a retracted state.

[0106] Figures 13 and 14 show front and side views of a robotic arm system 508 that more clearly show this nesting configuration. Figures 15 and 16 show isometric views that further clarify the structure of such a robotic arm system.

[0107] In each of Figures 13 and 14, a set of three views of a robot arm system is provided, with the top view showing both the first robot arm 520a and the second robot arm 520b. The middle view in each of Figures 13 and 14 highlights the first robot arm 520a with shading (and de-emphasizes the second robot arm 520b by drawing it with grey lines), and the bottom view in each of Figures 13 and 14 highlights the second robot arm 520b with shading (and de-emphasizes the first robot arm 520a by drawing it with grey lines). Somewhat similarly, the top view in Figure 15 shows the first robot arm 520a in black line font and the second robot arm 520b in grey line font. The bottom view in Figure 15 shows the first robot arm 520a, with the second robot arm 520b simply omitted. Similarly, the top diagram of Figure 16 shows the second robot arm 520b in black line font and the first robot arm 520a in grey line font. The bottom diagram of Figure 16 shows the second robot arm 520b, with the first robot arm 520a simply omitted.

[0108] As seen in FIGS. 13-16, the first robot arm 520a includes a plurality of first robot arm links. In the illustrated implementation, each first robot arm link includes a first base link 530a and a first intermediate arm link 532a. Each first robot arm 520a also includes a first end effector support arm 528a (see FIG. 14). The first end effector support arm 528a is pivotally connected to the first intermediate arm link 532a and supports the first end effector 540a relative to other portions of the first robot arm 520a. Each of the various first arm links may be pivotally connected to one or two other first arm links to form an articulated robot arm. In the illustrated implementation, as shown in FIG. 15, the first end effector support arms 528a are each pivotally connected to a different one of the two first intermediate arm links 532a so as to rotate about a corresponding axis of rotation 568 relative to the pivotally connected first intermediate arm link 532a. Similarly, the first intermediate arm links 532a are each pivotally connected to a different one of the two first base links 530a so as to rotate about a corresponding axis of rotation 568 relative to the pivotally connected first base link 530a. Finally, the first base links 530a are each pivotally connected to the torso unit 512 so as to rotate about a corresponding first axis 534a relative to the torso unit 512.

[0109] Similarly, each second robot arm link includes a second base link 530b and a second intermediate arm link 532b. Each second robot arm 520b also includes a second end effector support arm 528b (see FIG. 14). The second end effector support arm 528b is pivotally connected to the second intermediate arm link 532b and supports the second end effector 540b relative to the other portion of the second robot arm 520b. Each of the various second arm links may be pivotally connected to one or two other second arm links to form an articulated robot arm. In the illustrated implementation, as shown in FIG. 16, the second end effector support arms 528b are pivotally connected to different ones of the two second intermediate arm links 532b such that each second end effector support arm 528b can rotate about a corresponding axis of rotation 568 relative to the second intermediate arm link 532b to which it is pivotally connected. Similarly, the second intermediate arm links 532b are each pivotally connected to a different one of the two second base links 530b so as to rotate about a corresponding axis of rotation 568 relative to the pivotally connected second base link 530b. Finally, the second base links 530b are each pivotally connected to the fuselage unit 512 so as to rotate about a corresponding second axis 534b relative to the fuselage unit 512.

[0110] As shown, the first robot arm 520a and the second robot arm 520b are substantially identical in structure, shape, and size. However, each first robot arm 520a has a bypass elbow 552 as part of the rotation joint between the first intermediate arm link 532a and the first base link 530a of each first robot arm 520a. The bypass elbow may feature two structures that can rotate relative to each other and have a gap between them along the axis of rotation. Thus, other parts such as the second base link 530b and the end of the second intermediate arm link 532b that are pivotally connected to each other may be moved through the bypass elbow by passing through the gap. Such structures are therefore able to pass through the central axis of rotation between the first intermediate arm link 532a and the first base link 530a.

[0111] To further clarify the inner workings of such a robotic arm system, reference is made to FIG. 17, which shows a cross-sectional schematic diagram of such a robotic arm system. As shown, only half of a robotic arm system, such as robotic arm system 508, is visualized, with the other half (only partially shown) depicted in dashed lines. The robotic arm system includes a torso unit 1712, which may be rotatable about an axis of rotation 1714. A reference plane 1770 of the torso unit 1712 is also shown. The reference plane 1770 may be, for example, a generally symmetrical plane in the robotic arm system, perpendicular to the plane of the paper in FIG. 17, and may be coincident or coplanar with the axis of rotation 1714. A torso unit drive motor 1780 may be provided to input rotation to the torso unit 1712, so that the robotic arm system can rotate, for example, as shown in FIGS. 2-4.

[0112] The torso unit 1712 may include a first arm drive motor 1742a and a second arm drive motor 1742b. The first arm drive motor 1742a and the second arm drive motor 1742b may be configured to input rotation to a corresponding first robot arm or a corresponding second robot arm, respectively. In this particular example, the first arm drive motor 1742a and the second arm drive motor 1742b may be directly connected to the corresponding first robot arm or the corresponding second robot arm, and another first arm drive motor 1742a and another second arm drive motor 1742b may be provided on the opposite side of the reference plane 1770 to drive the other first robot arm and the other second robot arm, respectively. However, in other implementations, a single first arm drive motor 1742a and / or a single second arm drive motor 1742b may be provided. A single first arm drive motor 1742a and / or a single second arm drive motor 1742b are configured to simultaneously drive each of both first and / or both second robot arms, for example, by using a belt, gears, or other mechanism for transferring rotational force from a particular axis of rotation to another offset but parallel axis of rotation. In implementations where the first and / or second robot arms are not commonly driven, the first and / or second robot arms may be driven at different times than the other first or second robot arms in some such implementations, but generally it may be desirable to move both first robot arms in parallel / tandem and both second robot arms in parallel / tandem as well. However, this may reduce the throughput of wafers placed or picked by such a robot arm system.

[0113] As shown, the first arm drive motor 1742a is configured, when driven, to rotate the first base link 1730a of the first arm link 1726a relative to the torso unit 1712. The second arm drive motor 1742b is configured, when driven, to rotate the second base link 1730b of the second arm link 1726b relative to the torso unit 1712.

[0114] With respect to the second arm link 1726b, the second base link 1730b may be pivotally connected to the second middle arm link 1732b, as indicated by the bearings 1784 shown at the junctions between the second base link 1730b and the second middle arm link 1732b. While the various rotational junctions in FIG. 17 are generally indicated by representative bearings 1784, it will be understood that there may be a variety of ways such bearings may be positioned to achieve similar rotational motion, and the illustrated locations should not be considered limiting in any manner.

[0115] Using an internal pulley and drive belt system, the second intermediate arm link 1732b and the second end effector support arm 1728b, which may be pivotally connected to the second intermediate arm link 1732b, may also rotate in tandem with the rotation of the second base link 1730b relative to the fuselage unit, relative to the second arm link 1726b to which they are each pivotally connected.

[0116] For example, a second middle arm link drive pulley 1750b may be provided that is fixed in space relative to the fuselage unit 1712. Similarly, a second middle arm link pulley 1748b may be provided that is fixed in space relative to the second middle arm link 1732b. A belt 1782 may be provided that spans between the second middle arm link pulley 1748b and the second middle arm link drive pulley 1750b. The second middle arm link drive pulley 1750b may be twice the radial size of the second middle arm link pulley 1748b. Thus, when the second base link 1730b is rotated relative to the fuselage unit 1712, thereby rotating the second middle arm link drive pulley 1750b, this causes the belt 1782 between the second middle arm link pulley 1748b and the second middle arm link drive pulley 1750b to drive the second middle arm link pulley 1748b at twice the rotational speed (and in the opposite direction) of the second base link 1730b, which in turn causes the second middle arm link 1732b to rotate relative to the second base link 1730b twice as fast and in the opposite direction as the second base link 1730b rotates relative to the fuselage unit 1712.

[0117] The second intermediate arm link 1732b may also be internally configured with a belt and pulley system. The belt and pulley system may similarly rotate the second end effector support arm 1728b relative to the second intermediate arm link 1732b in tandem with the rotation of the second base link 1730b relative to the fuselage unit 1712. For example, the second intermediate arm link 1732b may have therein a second end effector support arm drive pulley 1746b and a second end effector support arm pulley 1746b. The second end effector support arm drive pulley 1746b is fixed in space relative to the second base link 1730b. The second end effector support arm pulley 1746b is fixed in space relative to the second end effector support arm 1728b. Another belt 1782 may be between the second end effector support arm drive pulley 1746b and the second end effector support arm pulley 1744b. In this case, the second end effector support arm drive pulley 1746b may have half the radius of the second end effector support arm pulley 1744b, thus rotating the second end effector support arm 1728b relative to the second intermediate arm link 1732b at half the speed at which the second intermediate arm link 1732b rotates relative to the second base link 1730b. With such an arrangement, a single rotation input to the second base link 1730b may generate a rotational motion in the second base link 1730b and the second intermediate arm link 1732b relative to the fuselage unit, while simply translating the second end effector support arm 1728b without rotating it relative to the fuselage unit 1712.

[0118] The first arm link 1726a may be similarly configured, for example, the first base link 1730a may be pivotally connected to the first intermediate arm link 1732a as indicated by the illustrated bearing 1784 at the junction between the first base link 1730a and the first intermediate arm link 1732a. Using a similar system of internal pulleys and drive belts, the first intermediate arm link 1732a and the first end effector support arm 1728a, which may be pivotally connected to the first intermediate arm link 1732a, may also rotate in tandem with the rotation of the first base link 1730a relative to the fuselage unit, relative to the first arm link 1726a to which they are each pivotally connected.

[0119] A first intermediate arm link drive pulley 1750a may be provided that is fixed in space relative to the fuselage unit 1712. Similarly, a first intermediate arm link pulley 1748a may be provided that is fixed in space relative to the first intermediate arm link 1732a. A belt 1782 may be provided that spans between the first intermediate arm link pulley 1748a and the first intermediate arm link drive pulley 1750a. The first intermediate arm link drive pulley 1750a may be twice the radial size of the first intermediate arm link pulley 1748a. Thus, when the first base link 1730a is rotated relative to the fuselage unit 1712, thereby rotating the first intermediate arm link drive pulley 1750a, this causes the belt 1782 between the first intermediate arm link pulley 1748a and the first intermediate arm link drive pulley 1750a to drive the first intermediate arm link pulley 1748a at twice the rotational speed (and in the opposite direction) of the first base link 1730a, which in turn causes the first intermediate arm link 1732a to rotate relative to the first base link 1730a twice as fast and in the opposite direction as the first base link 1730a rotates relative to the fuselage unit 1712.

[0120] The first intermediate arm link 1732a may also be internally configured with a belt and pulley system. The belt and pulley system may similarly rotate the first end effector support arm 1728a relative to the first intermediate arm link 1732a in tandem with the rotation of the first base link 1730a relative to the fuselage unit 1712. For example, the first intermediate arm link 1732a may have therein a first end effector support arm drive pulley 1746a and a first end effector support arm pulley 1746a. The first end effector support arm drive pulley 1746a is fixed in space relative to the first base link 1730a. The first end effector support arm pulley 1746a is fixed in space relative to the first end effector support arm 1728a. Another belt 1782 may be placed between the first end effector support arm drive pulley 1746a and the first end effector support arm pulley 1744a. In this case, the first end effector support arm drive pulley 1746a may have half the radius of the first end effector support arm pulley 1744a, thus rotating the first end effector support arm 1728a relative to the first intermediate arm link 1732a at half the speed at which the first intermediate arm link 1732a rotates relative to the first base link 1730a. With such an arrangement, a single rotation input to the first base link 1730a may generate rotational motion in the first base link 1730a and the first intermediate arm link 1732a relative to the fuselage unit, while simply translating the first end effector support arm 1728a without rotating it relative to the fuselage unit 1712.

[0121] As seen in second arm link 1726b, a shaft may be provided that extends upwardly from second base link 1730b and provides a fixed structure to which second end effector support arm drive pulley 1746b may be connected. The shaft may be asymmetrical along its length if desired. It will be appreciated that while the various illustrated arm links, pulleys, etc. are often shown as being continuous with other elements, in reality they may be provided by an assembly of multiple pieces that may be bolted together, for example, to form a "fixed" assembly.

[0122] The first arm link 1726a may have a similar arrangement, except that the shaft used to support the first end effector support arm drive pulley 1746a has an inner bypass section 1752a therein. The inner bypass section 1752a may include a first portion 1756a, a second portion 1758a, and a bridge section 1760a spanning between one end of the first portion 1756a and a corresponding end of the second portion 1758a. There may be a gap between the first portion 1756a and the second portion 1758a, which may be greater than the thickness of the revolute joint where the second base link 1730b pivotally connects with the second middle arm link 1732b. The bridge portion 1760a may be positioned such that a face of the bridge portion facing a corresponding axis of rotation of the rotation joint between the first base link 1730a and the first intermediate arm link 1732a is offset from that axis of rotation in a direction perpendicular to that axis of rotation such that the offset is sufficient to allow the rotation joint between the second base link 1730b and the second intermediate arm link 1732b to swing through the gap without colliding with the bridge portion 1760a when the first arm link 1726a is in a configuration consistent with the first robot arm in a retracted state.

[0123] An outer bypass section 1752b may also be provided at the portion of the first intermediate arm link 1732a that extends into the first base link 1730a to fixedly support the first intermediate arm link pulley 1748a. The outer bypass section 1752b may include a first section 1756b, a second section 1758b, and a bridge section 1760b that spans between one end of the first section 1756b and a corresponding end of the second section 1758b. There may be a gap between the first section 1756b and the second section 1758b, and the gap may be greater than the thickness of the first bypass elbow that includes the first section 1756a and the second section 1758a. The bridge portion 1760b may be positioned such that a face of the bridge portion facing a corresponding axis of rotation of the rotation joint between the first base link 1730a and the first middle arm link 1732a is offset from that axis of rotation perpendicular to the axis of rotation a distance greater than the distance between the face of the bridge portion 1760a of the medial bypass elbow 1752a that is furthest from the axis of rotation.

[0124] The use of such a bypass elbow allows the robot arm system of FIG. 17 (and the robot arm system 508 described herein above, as well as implementations described below) to be configurable such that the first base link 1730a and the second base link 1730b can be the same size, shape, and dimensions (or at least have their subparts that are the same size, shape, and dimensions). The first intermediate arm link 1732a and the second intermediate arm link 1732b can be the same size, shape, and dimensions as well. Such a configuration can therefore reduce the number of unique parts required, thereby lowering manufacturing costs. Such a configuration can also be more compact than some alternative designs, which can be advantageous when a transfer chamber used with such a robot arm system has limited space available.

[0125] The robotic arm system illustrated in Figure 17 features a first robotic arm and a second robotic arm capable of providing only translational movement of an end effector supported by the first robotic arm and the second robotic arm relative to the torso unit 1712. In some implementations, however, the first robotic arm and / or the second robotic arm may be configured to provide both translational and rotational movement of an end effector supported thereby relative to the torso unit 1712. Figure 18 shows a cross-sectional schematic diagram of an example robotic arm system featuring a first robotic arm and a second robotic arm configured to provide both translational and rotational movement of an end effector supported by the first robotic arm and the second robotic arm relative to the torso unit.

[0126] The robotic arm system of Figure 18 is substantially identical in structure to the robotic arm system illustrated in Figure 17. It will be understood that the descriptions of elements of the robotic arm system of Figure 17 that are referenced by the same last two digits (or the same last two digits and an a / b suffix) as corresponding elements in Figure 18 are equally applicable to those corresponding elements in Figure 18. For the sake of brevity, such elements will not be described individually below, but instead the reader is directed to the foregoing discussion of similar elements with the same last two digits (or the same last two digits and an a / b suffix) with respect to Figure 17 for the description of such elements in Figure 18.

[0127] 18 differs from the implementation of FIG. 17 in that the first intermediate link drive pulley 1850a and the second intermediate link drive pulley 1850b are not fixed relative to the fuselage unit 1812 as in FIG. 17, but are instead configured to be rotated by the arm rotation motor 1843. When the arm rotation motor 1843 is held stationary and one or the other of the first arm drive motor 1842a and the second arm drive motor 1842b is actuated, the first robotic arm or the second robotic arm, respectively, can translate its first or second end effector relative to the fuselage unit 1812. However, when the first arm drive motor 1842a, the second arm drive motor 1842b, and the arm rotation motor 1843 are all actuated in unison such that the first intermediate link drive pulley 1850a and the second intermediate link drive pulley 1850b are rotated in the same direction, by the same amount, and at the same speed as the first base link 1830a and the second base link 1830b, the first robotic arm and the second robotic arm may simply rotate about the corresponding first and second axes 1834a / b without any extension of their respective first or second end effectors. Such a robotic arm system may be operated to both extend / retract its end effector and rotate the robotic arm (and thus the end effector) simultaneously. This may be accomplished, for example, by rotating the first intermediate link drive pulley 1850a and the second intermediate link drive pulley 1850b a different amount and / or speed and / or direction than the first intermediate link drive pulley 1850a and / or the second intermediate link drive pulley 1850b.

[0128] As mentioned above, the end effectors of the first and second robot arms of FIG. 17 are rotatable in unison with respect to the transfer chamber / processing chamber(s) by rotation of the torso unit 1812. However, the end effectors of each pair of the first robot arms of FIG. 17 are not rotatable with respect to each other. Similarly, the end effectors of each pair of the second robot arms of FIG. 17 are also not rotatable with respect to each other. In contrast, the implementation of FIG. 18 not only allows the end effectors of the first and second robot arms to be rotatable in unison with respect to the transfer chamber / processing chamber(s), but also allows each first robot arm to be rotatable with respect to the other first robot arm and each second robot arm to be rotatable with respect to the other second robot arm. It should be noted that due to the fact that each set of first and second robotic arms are driven by a common first and second intermediate link drive pulley 1850a, 1850b, it may be desirable to rotate the first and second robotic arms of such a pair in tandem to avoid, for example, one robotic arm of the pair rotating and the other not rotating (or rotating at a different amount and / or speed) thereby extending or retracting.

[0129] An implementation such as that of FIG. 18 allows each first robot arm to be extended a different amount and rotated at a different relative angle compared to the other first robot arm. FIG. 19 shows an example of a robot arm system having a torso unit 1912 supporting two first robot arms and two second robot arms. Each first robot arm has a first base link 1930a, a first intermediate arm link 1932a, and a first end effector support arm 1928a supporting a first end effector 1940a. Each second robot arm has a second base link 1930b, a second intermediate arm link 1932b, and a second end effector support arm 1928b supporting a second end effector 1940b. In FIG. 19, both second robot arms are shown in a far extended state and the first robot arm is shown in a retracted state. Each second robot arm may be movable independently of the other second robot arm, for example, to extend farther away by a distance of up to +r, retract inward by a distance of up to -r, pivot left by an angle of up to -θ, and / or pivot right by an angle of up to +θ, or any combination thereof, from the position shown. This allows the center of the wafer supported by the second end effector 1940b to be independently repositioned to be centered on a pedestal that may be located below the second end effector 1940b. The dotted outlines shown represent the outlines of the second robot arm in the far extension state and the partially retracted state. The dashed outlines shown represent the outlines of the first robot arm and the second robot arm in the left rotation state and the right rotation state. It will be appreciated that the first robotic arm can be moved and repositioned independently in a similar manner to how the second robotic arm is shown to be rotatable and / or extendable / retractable when extended to a near or far extension state.

[0130] This allows, for example, each first robot arm to be controllable to perform a wafer centering operation relative to a pedestal of a processing chamber independently of and simultaneously with a wafer centering operation being performed by the other first robot arm, and thus both first robot arms can be controlled simultaneously to center the wafers they support above their respective pedestals.

[0131] It will be appreciated that the range of motion shown in Fig. 19, while feasible, is generally exaggerated compared to the amount of actual robot arm motion that may be performed during a wafer centering operation. For example, the amount that repositioning of the wafer may be required during a centering operation is typically on the order of 1 or 2 millimeters or less. Thus, the amount of extension / retraction or left / right rotation that may be required to perform wafer centering may be only on the order of 1 or 2 millimeters of extension and / or retraction and / or less than 1 degree of rotation.

[0132] Various alternative robotic arm systems that may be used in place of the robotic arm system described above are discussed below with reference to Figures 20 and 21.

[0133] 20 shows a plan view of an exemplary robotic arm system having a first robotic arm (shaded in the top view of FIG. 20) and a second robotic arm (shaded in the bottom view of FIG. 20) in which a first axis about which the first base link 2030 is configured to rotate is not coaxial with a second axis about which the corresponding second base link 2030b is configured to rotate. Thus, the first axis and the second axis may be spaced apart from each other, for example, on either side of a reference plane passing through the axis of rotation of the fuselage unit 2012. This allows the first robotic arm and the second robotic arm to be offset from each other in a direction perpendicular to their axes of extension. In such a configuration, the first robotic arm and the second robotic arm may be constructed identically, except that a spacer may be provided at the rotation joint between the first base link 2030a and the first intermediate arm link 2032a to vertically offset the first base link 2030a and the first intermediate arm link 2032a so that there is clearance for the second base link 2030b and the second intermediate arm link 2032b to pass therebetween. Such an arrangement, however, may omit the bypass elbow described above if the first robotic arm is sufficiently spaced from the second robotic arm such that the second intermediate arm link 2032b can rotate from its retracted position to its far extended position without contacting the spacer described above.

[0134] The first base link 2030a may have a first base link length 2036a. The first base link length 2036a defines the distance between a corresponding first axis of rotation for the rotation joint between the first base link 2030a and the fuselage unit 2012 and a corresponding axis of rotation for the rotation joint between the first base link 2030a and the first intermediate arm link 2032a. The first intermediate arm link may similarly have a first intermediate arm link length 2038a. The first intermediate arm link length 2038a defines the distance between a corresponding axis of rotation for the rotation joint between the first intermediate arm link 2032a and the first end effector support arm 2028a pivotally connected thereto. Similarly, the second base link 2030b may have a second base link length 2036b. The second base link length 2036b defines the distance between a corresponding second axis of rotation for the rotation joint between the second base link 2030b and the fuselage unit 2012 and a corresponding axis of rotation for the rotation joint between the second base link 2030b and the second intermediate arm link 2032b. The second intermediate arm link may similarly have a second intermediate arm link length 2038b. The second intermediate arm link length 2038b defines the distance between a corresponding axis of rotation for the rotation joint between the second intermediate arm link 2032b and the second end effector support arm 2028b pivotally connected thereto.

[0135] In the robotic arm system illustrated in Figure 20, the first base link length 2036a, the second base link length 2036b, the first middle arm link length 2038a, and the second middle arm link length 2038b are all the same length, as in the example robotic arm system described above with respect to Figures 13-17. However, while in the example robotic arm system described above with respect to Figures 13-17 the first and second axes on each side of the fuselage unit are coaxial, in the example of Figure 20 the two first axes are spaced apart from each other in a direction perpendicular to the first axes by a greater distance than the second axes are similarly spaced apart.

[0136] Another difference between the robot arm system of FIG. 20 and the robot arm systems previously described is in the first and second end effector support arms 2028a and 2028b, which may support a first and second end effector 2040a and 2040b, respectively. The first and second end effector support arms 2028a and 2028b may each feature two portions, similar to those in the robot systems of FIGS. 13-16. The first portion extends from a revolute joint that attaches the first or second end effector support arm 2028a or 2028b to a corresponding intermediate arm link, and the second portion terminates within the first or second end effector 2040a or 2040b, as appropriate. The two portions may be offset from one another along an axis perpendicular to the translation axis of each robot arm and may be joined by a corresponding offset jog portion that spans between the first and second portions. The first and second portions may also extend along a direction generally parallel to the translation axis. In some cases, for example, as the offset jog portion approaches an associated rotational joint, the first portion may simply become part of the offset jog portion, thus shortening the length of the first portion until the first portion is simply the end of the offset jog portion.

[0137] In the example of Figures 13-16, the above-mentioned portions and offset jog portions of each end effector support arm may be of similar size and dimension, and thus in some cases the first end effector support arm 528a and the second end effector support arm 528b may be provided using identical parts (at least with respect to their major structural parts). Thus, manufacturing is simplified and costs are reduced. In the implementation illustrated in Figure 20, this may potentially be the case, for example, when the centerline of the end effector for a given pair of adjacent first and second robot arms is positioned to coincide with the midway between the first and second axes for those robot arms, as well as the midway between the axes of rotation for the rotary joints between the end effector support arms and the intermediate arm links for those robot arms. However, in the example of FIG. 20, the associated offset for the first end effector support arm 2028a is slightly smaller than the associated offset for the second end effector support arm 2028b, such that the first end effector support arm 2028a and the second end effector support arm 2028b are constructed differently.

[0138] FIG. 21 shows a plan view of another exemplary robot arm system having a first robot arm (shaded in the top view of FIG. 21) and a second robot arm (shaded in the bottom view of FIG. 21), in which a first axis about which a first base link 2130 is configured to rotate is coaxial with a second axis about which a corresponding second base link 2130b is configured to rotate. Thus, the first axis of one first robot arm and the second axis of one second robot arm may be coaxial with each other, and the first axis of another first robot arm and the second axis of another second robot arm may be coaxial with each other, with the two pairs of first and second axes being spaced apart from each other. Such an arrangement is similar to that of the robot arm system of FIGS. 13-16, although in this example the first and second robot arms are not identical.

[0139] The first base link 2130a may have a first base link length 2136a. The first base link length 2136a defines the distance between a corresponding first axis of rotation of the rotation joint between the first base link 2130a and the torso unit 2112 and a corresponding axis of rotation of the rotation joint between the first base link 2130a and the first intermediate arm link 2132a. The first intermediate arm link may similarly have a first intermediate arm link length 2138a. The first intermediate arm link length 2138a defines the distance between a corresponding axis of rotation of the rotation joint between the first intermediate arm link 2132a and the first end effector support arm 2128a pivotally connected thereto. Similarly, the second base link 2130b may have a second base link length 2136b. The second base link length 2136b defines the distance between a corresponding second axis of rotation for the rotation joint between the second base link 2130b and the fuselage unit 2112 and a corresponding axis of rotation for the rotation joint between the second base link 2130b and the second intermediate arm link 2132b. The second intermediate arm link may similarly have a second intermediate arm link length 2138b. The second intermediate arm link length 2138b defines the distance between a corresponding axis of rotation for the rotation joint between the second intermediate arm link 2132b and the second end effector support arm 2128b pivotally connected thereto.

[0140] 21, the first base link length 2136a and the first intermediate arm link length 2138a may be the same, and the second base link length 2136b and the second intermediate arm link length 2138b may be the same, but the first base link length 2136a and the first intermediate arm link length 2138a may be greater than the second base link length 2136b and the second intermediate arm link length 2138b. The additional length of the first base link length 2136a and the first intermediate arm link length 2138a allows the rotation joint between the first base link 2130a and the first intermediate arm link 2132a to be positioned further outboard of the first axis compared to the rotation joint between the second base link 2130b and the second intermediate arm link 2132b. Thus, when the first robotic arm is in a retracted state, the second base link 2130b and the second middle arm link 2132b can swing past the first base link 2130a and the first middle arm link 2132a without colliding.

[0141] While the exemplary robotic arm systems discussed herein are bilaterally symmetrical, it will be understood that other implementations may have asymmetrical features. For example, a robotic arm system may be provided that features a first and second robot arm on a left side that are similar to the first and second robot arms for robotic arm system 508 of Figures 5-16, and a first and second robot arm on a right side that are similar to the first and second robot arms shown in Figures 20 or 21, thereby forming a robotic arm system that has bilateral asymmetry but also provides symmetrical translational features.

[0142] The robot arm system described above may enable direct positioning of the wafer transferred by the robot arm system in each of the four stations of a QSM type multi-station processing chamber, or similar processing chamber, as previously described. Such positioning may be performed wafer by wafer by centering each wafer on the destination pedestal or other wafer support structure using an active wafer centering (AWC) system, as commonly used in the industry. In an AWC system, an optical beam sensor fixed relative to the semiconductor processing chamber may detect when an optical beam emitted by the optical beam sensor is crossed by the wafer being transferred into the chamber. The position of the end effector of the wafer transfer robot at the time when each optical beam is broken by the wafer during such transfer may be used to determine the actual position of the wafer relative to the end effector (e.g., the center of the wafer relative to the first or second position of the first or second end effector, as previously described). The wafer transport robot may then be controlled to make small adjustments to the motion of the robot arm transferring the wafer to align the center of the wafer with the desired position of the center of the wafer on the destination pedestal (or wafer support). Such adjustments are typically very small, for example, on the order of less than a millimeter.

[0143] FIG. 22 shows a schematic diagram of two AWC sensor systems. The two AWC sensor systems may be used to obtain separate wafer center measurements relative to the end effector for a configuration of two wafers supported in a stacked arrangement. Such an AWC sensor system may be referred to as a dual-wafer AWC sensor system. In FIG. 22, the first wafer 2216a and the second wafer 2216b are supported in a configuration where the first wafer 2216a is directly above the second wafer 2216b. Both the first wafer 2216a and the second wafer 2216b are supported by a common end effector 2240 as they pass into the processing chamber via the wafer transfer path 2274. AWC sensor systems 2286 may be provided on both sides of the wafer transfer path 2274. Each AWC sensor system 2286 may have an E-shaped configuration, with the central horizontal leg of the "E" having a light emitter / light source 2288 directing optical beams upward and downward. The central horizontal leg of the "E" may be positioned to be interposed between the two wafers 2216a and 2216b supported by the end effector 2240, and such that each of the optical beams emitted by the light emitter / light source 2288 intersects a different one of the two wafers 2216a and 2216b as the end effector 2240 moves the wafers 2216a and 2216b through the wafer transfer path 2274. The top and bottom legs of the "E" may each house an optical receiver 2290 or other sensor for detecting light emitted by one of the two light emitters / light sources 2288. Such AWC sensor systems 2286 may be provided on both sides of the wafer transfer path 2274. A second set of such AWC sensor systems 2286 (not shown) may be provided at different heights within the wafer transfer path 2274 to allow similar wafer center measurements to be obtained for wafers transferred by different end effectors at lower or higher positions. Such an AWC sensor system would allow, for example, each wafer transferred by a robotic arm system discussed herein using end effectors supporting the wafer in a top-bottom configuration to have an AWC measurement obtained.The AWC measurements allow the AWC system for a multi-station chamber to fine-tune the placement of each wafer on the destination pedestal or wafer support, thus allowing for individualized wafer centering within each station. It will be understood that the end effectors discussed herein that are configured to transfer two wafers in an up-down configuration may be configured to perform the transfer of two wafers in an up-down configuration with the centers of the two wafers generally coincident with a common vertical axis (e.g., with one wafer centered above or below the other), or alternatively, with the centers of the two wafers horizontally offset and generally not intersecting the common vertical axis. Both types of end effectors are considered within the scope of the present disclosure.

[0144] 23-44 show isometric views of an exemplary semiconductor processing tool, also referred to simply as the "tool" hereinafter, which includes a transfer chamber 2302 and a processing chamber 2304. The transfer chamber 2302 is provided with a robotic arm system similar to that shown in FIGS. 13-16. The processing chamber 2304 has four wafer processing stations, each with its own pedestal 2306. The station / pedestal 2306 furthest from the transfer chamber 2302 is designated as the "far" station or "far" pedestal 2306, and the station / pedestal 2306 closest to the transfer chamber 2302 is designated as the "near" station or "near" pedestal 2306. The robotic arm system includes a pair of first robotic arms 2320a and a pair of second robotic arms 2320b, both of which are supported by a torso unit 2312. These features are common to all of FIGS. 23-44. Also visible in Figure 23 (omitted from other figures) is a controller 2301. The controller 2301 may be communicatively coupled to the robotic arm system and / or processing chambers 2304 and may be used to control the operation of the torso unit, the first robotic arm, and the second robotic arm, as well as potentially the actuation of the lift pins of the pedestal 2306. The controller 2301 may also in some cases be communicatively coupled to an AWC system as described above.

[0145] Figure 23 shows the tool in operation with a first set of four wafers 2316 loaded onto the end effector of the first robot arm 2320a and a second set of four wafers 2316 on the pedestal 2306. The second set of four wafers 2316 may have just completed one or more semiconductor processing operations in the processing chamber 2304 and it may be desirable for them to be removed and replaced with the first set of wafers 2316. Figures 24-34 show various stages of this process.

[0146] In FIG. 24, a wafer 2316 on the proximal pedestal 2306 has been elevated from the proximal pedestal 2306 by lift pins 2318 to a height sufficient to allow an end effector of a second robot arm 2320 b to move beneath the wafer 2316 .

[0147] In FIG. 25, the second robotic arm 2320 b has been transitioned from a retracted state to a near-extended state, thus positioning its end effector below the wafer 2316 , which is elevated by lift pins 2318 above the near pedestal 2306 .

[0148] 26, the lift pins 2318 for the near pedestal 2306 are retracted such that the wafer 2316 supported thereby is lowered onto the end effector of the second robot arm 2320b. At the same time, the lift pins 2318 for the far pedestal 2306 are actuated to lift the wafer 2316 supported by the far pedestal 2306 to a height that is somewhat lower than the height to which the lift pins 2318 for the near pedestal 2306 lifted the wafer 2316 from the near pedestal 2306. This height may be selected to place the wafer 2316 from the far pedestal 2306 at a height between the upper and lower blades of the end effector of the second robot arm 2320b. Alternatively, if the robotic arm system has Z-axis drive capability, the lift pins 2318 may instead lift the wafer 2316 to a similar height as the near pedestal 2306, and the robotic arm system may instead change the height of the second robotic arm 2320b so that the wafer 2316 being lifted by the lift pins is at the same relative height to the end effector of the second robotic arm 2320b. It will also be appreciated that the wafer 2316 may be lifted from the far pedestal 2306 at an earlier stage, such as in conjunction with lifting the wafer 2316 from the near pedestal 2306.

[0149] 27, the second robot arm 2320b has been transitioned from a near extension state to a far extension state, thus manipulating its end effector such that a wafer 2316 lifted from the far pedestal 2306 by corresponding lift pins 2318 is positioned below the wafer 2316 already supported by the end effector of the second robot arm 2320b, but above the lower blade of the same end effector. The wafer 2316 supported by the lift pins 2318 for the far pedestal 2306 may then be lowered onto the end effector for the second robot arm 2320b.

[0150] 28, the second robotic arm 2320b is transitioned from the far-extended state to the retracted state, thus withdrawing all four wafers 2316 of the second set of wafers 2316 from the processing chamber 2304. As shown, at this point there are eight wafers 2316 contained within the transfer chamber 2302 and the processing chamber 2304 is empty and ready to receive the wafers 2316 of the first set of wafers 2316.

[0151] In FIG. 29, the first robot arm 2320a has been transitioned to a far extended state, thus introducing a first set of wafers 2316 into the processing chamber 2304 and positioning the first set of wafers 2316 above the far pedestal 2306.

[0152] In Figure 30, the lift pins 2318 for the far pedestal 2306 are extended to lift two wafers 2316 supported at locations below the end effectors of the first robot arm from those end effectors. If an AWC system is used to allow individual centering of each wafer being placed, the robot arm system may be controlled to first center one of the two wafers 2316 supported at locations below one of the two first robot arms 2320a on the corresponding far pedestal 2306, and then only the lift pins of the corresponding far pedestal 2306 will lift that single wafer 2316 from the corresponding end effector. Once the wafer 2316 is no longer supported by an end effector, but instead supported by the lift pins 2318 for the far pedestal 2306 on which the wafer 2316 is located, the robot arm system may be further controlled to center the wafer 2316 supported at an underside position of the end effector for the other first robot arm 2320a over the other far pedestal 2306, and then extend the lift pins 2318 for the other far pedestal 2306 to lift the wafer 2316 supported at an underside position of the end effector for the other first robot arm 2320a from that end effector. At this stage, both wafers 2316 that were previously supported at a underside position by the end effector of the first robot arm 2320a are centered above their respective far pedestals 2306 and are no longer supported by the end effector of the first robot arm 2320a. It will be appreciated that if the robotic arm system used is similar to that illustrated in FIG. 18, the wafer centering operations may be performed simultaneously rather than sequentially, thereby reducing the overall time required to position the wafer 2316 on the remote pedestal 2306 within the processing chamber 2304.

[0153] In FIG. 31, the first robot arm has been transitioned from a far-extended state to a near-extended state, such that the wafer 2316 previously supported by the end effector of the first robot arm 2320a is now supported by corresponding lift pins 2318, floating above the far pedestal 2306.

[0154] In Fig. 32, the lift pins 2318 for the near pedestal 2306 are extended to lift two wafers 2316 still supported by the first robot arm 2320a from the end effector of the first robot arm. As described above with respect to Fig. 30, the lift pins 2318 for the near pedestals 2306 may be staggered raised so that each wafer 2316 still supported by the first robot arm 2320a is centered over its near pedestal 2306 prior to the lift pins 2318 for each pedestal being raised to lift that wafer 2316 from the supporting first robot arm 2320a. In implementations that support it, such centering may be performed simultaneously by each first robot arm 2320a.

[0155] In FIG. 33, the first robot arm 2320 a has been transitioned to a retracted state so that the remaining pair of wafers 2316 are supported on the lift pins 2318 of the proximal pedestal 2306 .

[0156] 34, the lift pins 2318 of the near pedestal 2306 are retracted such that the last two wafers 2316 of the first set of wafers 2316 are lowered onto their respective near pedestals 2306. Of course, it will be appreciated that the wafers 2316 disposed on the far pedestals 2306 do not have to be lowered onto their respective far pedestals 2306 as part of the operations illustrated in FIG. 32, but instead may be lowered at a later stage, for example at the same time that the wafers 2316 are lowered onto the near pedestals 2306 (e.g., during the operations illustrated in FIG. 34).

[0157] 35-44 show similar operations as discussed with respect to FIGS. 24-34, but with a first set of wafers 2316 initially in the processing chamber 2304 and a second set of wafers 2316 in the transfer chamber 2302 and supported by a second robot arm 2320b. In practice, once a set of wafers is removed from a processing chamber, the set of wafers is typically moved to another processing chamber or to a set of load locks for transfer out of the tool. A different set of wafers from yet another processing chamber or such load lock is loaded onto the robot arm system for introduction into the processing chamber(s) of the tool.

[0158] 35, the wafers 2316 on the near pedestal 2306 have been lifted from the near pedestal 2306 by the lift pins 2318 to a height sufficient to allow the end effector of the first robot arm 2320a to move beneath the wafers 2316. The first robot arm 2320a has also been transitioned from a retracted state to a near extended state, thus positioning its end effector beneath the wafers 2316, which have been lifted by the lift pins 2318 above the near pedestal 2306.

[0159] 36, the lift pins 2318 for the near pedestal 2306 are retracted such that the wafer 2316 supported thereby is lowered onto the end effector of the first robot arm 2320a. At the same time, the lift pins 2318 for the far pedestal 2306 are actuated to lift the wafer 2316 supported by the far pedestal 2306 to a height that is somewhat lower than the height to which the lift pins 2318 for the near pedestal 2306 lifted the wafer 2316 from the near pedestal 2306. This height may be selected to place the wafer 2316 from the far pedestal 2306 at a height between the upper and lower blades of the end effector of the first robot arm. Alternatively, if the robotic arm system has Z-axis drive capability, the lift pins 2318 may instead lift the wafer 2316 to a similar height as the near pedestal 2306, and the robotic arm system may instead change the height of the first robotic arm 2320a so that the wafer 2316 being lifted by the lift pins is at the same relative height to the end effector of the first robotic arm 2320a. It will also be appreciated that the wafer 2316 may be lifted from the far pedestal 2306 at an earlier stage, such as in conjunction with lifting the wafer 2316 from the near pedestal 2306.

[0160] 37, the first robot arm 2320a has been transitioned from a near extension state to a far extension state, thus manipulating its end effector such that a wafer 2316 lifted from the far pedestal 2306 by corresponding lift pins 2318 is positioned below the wafer 2316 already supported by the end effector of the first robot arm 2320a, but above the lower blade of the same end effector. The wafer 2316 supported by the lift pins 2318 for the far pedestal 2306 may then be lowered onto the end effector for the first robot arm 2320a.

[0161] 38, the second robotic arm 2320b is transitioned from the far-extended state to the retracted state, thus withdrawing all four wafers 2316 of the second set of wafers 2316 from the processing chamber 2304. As shown, at this point, the transfer chamber 2302 once again contains eight wafers 2316, and the processing chamber 2304 is empty and ready to receive the wafers 2316 of the second set of wafers 2316.

[0162] In FIG. 39, the second robot arm 2320b has been transitioned to a far-extended state, thereby introducing a second set of wafers 2316 into the processing chamber 2304 and positioning the second set of wafers 2316 above the far pedestal 2306.

[0163] In Figure 40, the lift pins 2318 for the far pedestal 2306 are extended to lift two wafers 2316 supported at an underside location of the end effector of the second robot arm 2320b from those end effectors. If an AWC system is used to allow individual centering of each wafer being placed, as described above with respect to Figures 30 and 32, the robot arm system may be controlled to first center one of the two wafers 2316 supported at an underside location of one of the two second robot arms 2320b on the corresponding far pedestal 2306, and then only the lift pins of the corresponding far pedestal 2306 may lift that single wafer 2316 from the corresponding end effector. Once the wafer 2316 is no longer supported by an end effector, but instead supported by the lift pins 2318 for the far pedestal 2306 on which the wafer 2316 is to be placed, the robot arm system may be further controlled to center the wafer 2316 supported at a location below the end effector for the other, second robot arm 2320b on the other far pedestal 2306, and then extend the lift pins 2318 for the other far pedestal 2306 to lift the wafer 2316 supported at a location below the end effector for the other, second robot arm 2320b from that end effector. As previously mentioned, if the robot arm system used is similar to that illustrated in FIG. 18, the wafer centering operations may be performed simultaneously rather than sequentially, thereby reducing the overall time required to place the wafer 2316 on the far pedestal 2306 in the processing chamber 2304. At this stage, both wafers 2316, which were previously supported in a lower position by the end effector of the second robot arm 2320b, are centered above their respective remote pedestals 2306 and are no longer supported by the end effector of the second robot arm 2320b.

[0164] In FIG. 41, the second robot arm 2320b has been transitioned from a far-extended state to a near-extended state, such that the wafer 2316 previously supported by the end effector of the second robot arm 2320b is now supported by corresponding lift pins 2318, floating above the far pedestal 2306.

[0165] In Figure 42, the lift pins 2318 for the near pedestal 2306 are extended to lift the two wafers 2316 still supported by the second robot arm 2320b from the end effector of the second robot arm 2320b. As discussed above with respect to Figures 30, 32, and 40, the lift pins 2318 for the near pedestals 2306 may be raised in a staggered manner, such that each wafer 2316 still supported by the second robot arm 2320b is centered over its near pedestal 2306 prior to the lift pins 2318 for each pedestal being raised to lift that wafer 2316 from the supporting second robot arm 2320b. Such centering may be performed simultaneously or sequentially, depending on the particular configuration of the robot arm system used.

[0166] In FIG. 43, the second robot arm 2320 b has been transitioned to a retracted state so that the remaining pair of wafers 2316 are supported on the lift pins 2318 of the proximal pedestal 2306 .

[0167] 44, the lift pins 2318 of the near pedestal 2306 are retracted so that the last two wafers 2316 of the second set of wafers 2316 are lowered onto their respective near pedestals 2306. Of course, it will be appreciated that the wafers 2316 disposed on the far pedestals 2306 do not have to be lowered onto their respective far pedestals 2306 as part of the operation illustrated in FIG. 42, but instead may be lowered at a later stage, for example at the same time that the wafers 2316 are lowered onto the near pedestals 2306 (e.g., during the operation illustrated in FIG. 44).

[0168] Although other sequences of operations may be performed using the robotic arm system described above, such alternative sequences may require additional movements, such as placing both robotic arms in a retracted state more frequently, that may lengthen the wafer transfer process and reduce throughput. These alternative uses of the robotic transport systems discussed herein are also considered to be within the scope of the present disclosure, although they may be less efficient.

[0169] The above discussion has focused almost entirely on robot arm systems featuring two pairs of robot arms. However, as previously described in this disclosure, some implementations of the robot arm systems discussed herein may feature only a single pair of opposing robot arms mounted on a common torso unit. Robot arm systems with two pairs of robot arms, although more expensive and more complex to control, generally provide significant throughput advantages in that one pair of robot arms can be used to hold and support a set of wafers to place in a chamber, and the other pair of robot arms can be used to remove a set of wafers from the chamber and place a waiting set. Thus, the wafers to be placed can be delivered into a chamber immediately after the wafers in the chamber are removed, without any gross movement of the torso unit. A robot arm with only a single pair of opposing robot arms does not have this capability. Any wafers removed from a chamber by such a robotic arm system must be withdrawn from the chamber, rotated to face another chamber or wafer receiving location, placed in the new location, and then retrieve another set of wafers to be delivered to the chamber that originally received the first set. This significantly increases the number of operations required and therefore the time it takes to swap one set of wafers for another within a processing chamber.

[0170] However, such a throughput penalty may not be an issue in semiconductor processing tools where a chamber cannot immediately load the next set of wafers after removing a set of wafers that have completed processing. For example, if a semiconductor processing tool is configured to perform a post-processing cleaning operation on a chamber after each set of wafers processed in the chamber is removed, there may be a period of time after the wafers are removed where the next set of wafers cannot be placed therein because such a cleaning operation is being performed. If the duration of the cleaning cycle is long enough, the robot arm system will be able to deliver the removed wafers to the next target location, retrieve the next set of wafers to be processed, and position it so that it can be inserted into the processing chamber as soon as the cleaning operation is completed, all before the cleaning operation is finished. In such situations, there is an external parallel throughput constraint that is more restrictive than the throughput constraint of the robot arm, so there is virtually no throughput penalty for using such a more limited robot arm system.

[0171] In view of the above, it will be appreciated that the robotic arm systems discussed herein may, in some implementations, include only a single pair of opposing robotic arms supported by a common torso unit. Two examples of such robotic arm systems are discussed below with reference to Figures 45-48.

[0172] 45 shows an isometric view of an example of a robotic arm system having only a single pair of robotic arms. The illustrated robotic arm system includes robotic arms 4520, each of which includes a base link 4530, a middle arm link 4532, and an end effector support arm 4528 supporting an end effector 4540. The base links 4530 may both be supported by a common torso unit 4512 and may be pivotally connected to the torso unit 4512 such that they are pivotable about corresponding axes 4534 relative to the torso unit 4512. The middle arm links 4532 may each be connected to a different one of the two base links 4530 such that they are pivotable about corresponding axes of rotation 4568. The end effector support arms 4528 may each be connected to a different one of the two middle arm links 4532 such that they are pivotable about corresponding axes of rotation 4568.

[0173] FIG. 46 shows a cross-sectional schematic diagram of one such robotic arm system. As shown, only half of the robotic arm system is visible, with the other half (only partially shown) depicted in dashed lines. The robotic arm system includes a torso unit 4612 that may be rotatable about an axis of rotation 4614. A reference plane 4670 of the torso unit 4612 is also shown. The reference plane 4670 may be, for example, a generally symmetrical plane of the robotic arm system, perpendicular to the plane of the paper of FIG. 46 and coincident with the axis of rotation 4614. A torso unit drive motor 4680 may be provided to input rotation to the torso unit 4612, so that the robotic arm system can rotate, for example, in a manner similar to that shown in FIGS. 2-4.

[0174] The torso unit 4612 may include an arm drive motor 4642 that may be configured to input rotation to a corresponding one of the robot arms. In this particular example, the arm drive motor 4642 is directly connected to the corresponding robot arm, and on the opposite side of the reference plane 4670, another arm drive motor 4642 may be provided to drive the other robot arm. However, in other implementations, a single arm drive motor 4642 may be provided. The single arm drive motor 4642 is configured to drive both robot arms simultaneously, for example, by using a belt, gears, or other mechanism for transferring rotational force from a particular axis of rotation to another offset but parallel axis of rotation. In implementations where the robot arms are not commonly driven, each robot arm may be driven at a different time than the other robot arm in some such implementations, but generally it may be desirable to move both robot arms in parallel / tandem. However, this may reduce the throughput of wafers placed or picked by such a robot arm system.

[0175] As shown, the arm drive motor 4642, when driven, is configured to rotate the base link 4630 of the arm link 4626 relative to the fuselage unit 4612. The base link 4630 may be pivotally connected to the middle arm link 4632, as indicated by the bearings 4684 shown at the junctions between the base link 4630 and the middle arm link 4632. As with FIGS. 17 and 18, the various rotational junctions in FIG. 46 are generally indicated by representative bearings 4684, however, it will be understood that there may be a variety of ways such bearings may be positioned to achieve similar rotational motion and the illustrated locations should not be considered limiting in any manner.

[0176] Using a system of internal pulleys and drive belts, the intermediate arm link 4632, and the end effector support arm 4628 which may be pivotally connected to the intermediate arm link 4632, may also rotate in tandem with the rotation of the base link 4630 relative to the fuselage unit, relative to the arm link 4626 to which it is each pivotally connected.

[0177] For example, a middle arm link drive pulley 4650 may be provided that is fixed in space relative to the fuselage unit 4612. Similarly, a middle arm link pulley 4648 may be provided that is fixed in space relative to the middle arm link 4632. A belt 4682 may be provided that spans between the middle arm link pulley 4648 and the middle arm link drive pulley 4650. The middle arm link drive pulley 4650 may be twice the radial size of the middle arm link pulley 4648. Thus, when the base link 4630 is rotated relative to the fuselage unit 4612, and thus the middle arm link drive pulley 4650 is rotated, this causes the belt 4682 that spans between the middle arm link pulley 4648 and the middle arm link drive pulley 4650 to drive the middle arm link pulley 4648 at twice the rotational speed (and in the opposite direction) of the base link 4630. This causes the middle arm link 4632 to rotate relative to the base link 4630 twice as much as, and in the opposite direction as, the base link 4630 rotates relative to the fuselage unit 4612 .

[0178] The intermediate arm link 4632 may also be configured internally with a belt and pulley system that may similarly rotate the end effector support arm 4628 relative to the intermediate arm link 4632 in tandem with the rotation of the base link 4630 relative to the fuselage unit 4612. For example, the intermediate arm link 4632 may have an end effector support arm drive pulley 4646 and an end effector support arm pulley 4646 therein. The end effector support arm drive pulley 4646 is fixed in space relative to the base link 4630. The end effector support arm pulley 4646 is fixed in space relative to the end effector support arm 4628. Another belt 4682 may run between the end effector support arm drive pulley 4646 and the end effector support arm pulley 4644. In this case, the end effector support arm drive pulley 4646 may have half the radius of the end effector support arm pulley 4644, thus causing the end effector support arm 4628 to rotate relative to the intermediate arm link 4632 half as fast as the intermediate arm link 4632 rotates relative to the base link 4630. With such an arrangement, a single rotational input to the base link 4630 may cause rotational motion in the base link 4630 and intermediate arm link 4632 relative to the fuselage unit, while simply translating the end effector support arm 4628 without rotating it relative to the fuselage unit 4612.

[0179] As seen in arm link 4626, a shaft may be provided that extends upwardly from the base link 4630 and provides a fixed structure to which an end effector support arm drive pulley 4646 may be connected. The shaft may be asymmetric along its length if desired. It will be appreciated that while the various illustrated arm links, pulleys, etc. are often shown as being continuous with other elements, in reality they may be provided by an assembly of multiple pieces that may be bolted together, for example, to form a "fixed" assembly.

[0180] The robotic arm system of FIG. 46 features robotic arms that can extend or retract (independently of each other when driven by separate arm drive motors, or dependent together when driven by a common arm drive motor) relative to the torso unit 4612. Such robotic arms can also be rotated in unison about an axis with the torso unit 4612 rotating about that axis, but such robotic arms cannot rotate relative to the torso unit 4612. For clarity, "rotation of the robotic arm" and the like refers to rotation of the end effector of the robot arm. For example, the various arm links of the robotic arm of FIG. 46 necessarily rotate relative to the torso unit 4612 during any movement of the robot arm, but the end effector of the robot arm can only translate relative to the torso unit 4612 without rotating. It will therefore be understood that the robotic arm of FIG. 46 cannot rotate relative to the torso unit 4612.

[0181] The robot arm system of Figure 46 may of course be used to pick or place wafers into a processing chamber in much the same manner as illustrated in Figures 23-44 for the first robot arm or the second robot arm of the robot arm system illustrated in Figures 23-44, except that the operations performed with both the first and second robot arm pairs of Figures 23-44 are instead performed with a single pair of robot arms, and thus, for example, only a single set of four wafers is processed at a time by the robot arm system, and additional robot arm system operations are required to be performed, for example, during the operations of Figures 28 and 29 to remove from the robot arm the set of wafers retrieved from the processing chamber by the robot arm in Figure 27, and to place on the robot arm another set of wafers to be placed into the processing chamber in Figure 29. Similar additional robot arm system operations would also be required to be performed during the operations of Figures 38 and 39.

[0182] As discussed with respect to Figure 46, a robotic arm system using a single pair of robotic arms supported by a fuselage unit may also be designed to allow rotation of the robotic arms relative to the fuselage unit, similar to the capabilities of the robotic arm system of Figure 18. Such implementations are discussed below with reference to Figures 47 and 48.

[0183] The robotic arm system of Figure 47 is substantially identical in structure to the robotic arm system illustrated in Figure 46. It will be understood that the descriptions of elements of the robotic arm system of Figure 46 that are referenced by the same last two digits as corresponding elements in Figure 47 are equally applicable to those corresponding elements in Figure 47. For the sake of brevity, such elements will not be described individually below, but instead the reader is directed to the foregoing discussion of similar elements with the same last two digits with respect to Figure 46 for the description of such elements in Figure 47.

[0184] The implementation of FIG. 47 differs from that of FIG. 46 in that the intermediate link drive pulley 4750 is not fixed relative to the torso unit 4712 as in FIG. 46, but instead is configured to be rotated by the arm rotation motor 4743. When the arm rotation motor 4743 is held stationary and the arm drive motor 4742 is actuated, the robot arm may translate its end effector relative to the torso unit 4712. However, when the arm drive motor 4742 and the arm rotation motor 4743 are both actuated in unison such that the intermediate link drive pulley 4750 is rotated in the same direction, by the same amount, and at the same speed as the base link 4730, the robot arm may simply rotate about the first 4734 without any extension or contraction of its end effector. Such a robot arm system may be operated to both extend / retract its end effector and rotate the robot arm (and thus the end effector) relative to the torso unit simultaneously. This may be accomplished, for example, by rotating the intermediate link drive pulley 4750 a different amount and / or speed and / or direction than the intermediate link drive pulley 4750.

[0185] As previously discussed, the end effectors of the robot arms of FIG. 46 are rotatable in unison with respect to the transfer chamber / processing chamber(s) by rotation of the torso unit 4712. However, the end effectors of the robot arms of FIG. 46 are not rotatable with respect to each other. In contrast, the implementation of FIG. 47 not only allows the end effectors of the robot arms to be rotatable in unison with respect to the transfer chamber / processing chamber(s), but also allows each robot arm to be rotatable with respect to the other robot arm and with respect to the torso unit 4712.

[0186] An implementation such as that of FIG. 47 allows each robot arm to be extended a different amount and rotated at a different relative angle compared to the other robot arm. FIG. 48 shows an example of a robot arm system having a torso unit 4812 supporting two robot arms, each having a base link 4830, a mid-arm link 4832, and an end effector support arm 4828 supporting an end effector 4840. In FIG. 48, the robot arms are shown in a far extended state. Each robot arm, having the configuration as shown in FIG. 47, may be movable independently of the other robot arm, for example, to extend far a distance of up to +r, retract in a distance of up to -r, pivot left an angle of up to -θ, and / or pivot right an angle of up to +θ, or any combination thereof, from the position shown. This allows the center of the wafer supported by the end effector 4840 to be independently repositioned to be centered on a pedestal that may be located below the end effector 4840. The dotted outlines shown represent the outline of the robot arm in a far extension state and a partially retracted state, and the dashed outlines show the outline of the robot arm in a left rotation state and a right rotation state.

[0187] It will be appreciated that the range of motion shown in Fig. 48, while feasible, is generally exaggerated compared to the amount of actual robot arm motion that may be performed during a wafer centering operation. For example, the amount that repositioning of the wafer may be required during a centering operation is typically on the order of 1 or 2 millimeters or less. Thus, the amount of extension / retraction or left / right rotation that may be required to perform wafer centering may be only on the order of 1 or 2 millimeters of extension and / or retraction and / or less than 1 degree of rotation.

[0188] Such implementations may, for example, allow each robot arm to be controllable to perform a wafer centering operation relative to a processing chamber pedestal independently of and simultaneously with a wafer centering operation being performed by the other robot arm, such that both robot arms are simultaneously controllable to center the wafers they support above their respective pedestals.

[0189] It will be appreciated that a hybrid of the robot arm systems of FIG. 46 and FIG. 47 may also be employed, for example, where one of the two robot arms is configured as illustrated in FIG. 46 and the other is configured as illustrated in FIG. 47. In such implementations, each robot arm would be independently controllable to extend, retract, and / or rotate relative to the transfer chamber housing the robot arm system (and the processing chamber in which the wafer is disposed). Thus, a wafer supported thereby may simultaneously undergo centering operations associated with two different pedestal positions within the processing chamber. In such implementations, adjustment of the rotation of a robot arm configured as illustrated in FIG. 46 is provided by rotating a torso unit supporting the robot arm. By combining such rotation of the torso unit with the extension or retraction of the robot arm, such a robot arm may be controlled to move the wafer it supports in any direction by an amount necessary to center the wafer on a desired target position. Similarly, in such implementations, adjustment of the rotation of a robot arm configured as illustrated in FIG. 47 is provided by rotating the robot arm relative to the torso unit. By combining rotational movement of such an arm relative to the torso unit with extension or retraction of the robot arm relative to the torso unit, such a robot arm may also be controlled to move the wafer it supports in any direction by the amount necessary to center the wafer over a desired target location. However, it will be understood that any rotational movement of the torso unit made to adjust the rotational position of a robot arm configured as illustrated in Figure 46 will necessarily cause a robot arm configured (and also supported by) as illustrated in Figure 47 to similarly rotate.A robot arm configured as shown in FIG. 47 may therefore need to be additionally rotated and / or extended / retracted to "correct" the rotational movement resulting from the rotation of the fuselage unit as part of the rotational adjustment of the robot arm configured as shown in FIG. 46. Such a hybrid system, although more kinematically complex than the system shown in FIG. 47, may provide similar performance as that shown in FIG. 47 while providing the advantage of requiring one less motor than is required to support the implementation of FIG. 47. A similar approach may also be employed in a hybrid version of a robot arm system having two pairs of robot arms, for example a first robot arm and a second robot arm on one side of the fuselage unit configured as shown in FIG. 17 and a first robot arm and a second robot arm on the other side of the fuselage unit configured as shown in FIG. 18.

[0190] It will be appreciated that the robotic arm systems discussed herein are configured to provide a transfer chamber based wafer transport solution that is capable of simultaneously placing a pair of wafers in adjacent stations adjacent to the transfer chamber, as well as simultaneously placing a pair of wafers in adjacent stations located on the opposite side of the transfer chamber relative to the first pair of stations.

[0191] In some such implementations, it may be desirable to reduce the overall footprint of such a semiconductor processing tool while still having a quad station module connected to the transfer chamber. To that end, the transfer chamber may be roughly the same size as the quad station module, thereby naturally limiting the size that a robot arm system located within the transfer chamber in the reduced state may have. At the same time, such a robot arm system may be required to have a reach roughly the same as the length or width of the transfer chamber or adjacent QSM, as the case may be. In some implementations, to provide the required amount of reach while allowing the transfer chamber to be roughly the same size as the adjacent QSM, the robot arm system may be designed with certain structural features that allow the robot arm system to achieve the maximum reach required to directly place a wafer within any station of the adjacent QSM while efficiently using the space available within such transfer module.

[0192] For example, when such a robot arm system is in a retracted state, as a body unit of the robot arm system rotates relative to the transfer chamber, the part of the robot arm system furthest from the axis of rotation about which the body unit rotates (including, in this case, any wafers that can be transported by the robot arm system) may define a clearance circle (centered about said axis of rotation). This clearance circle must generally fall inside the transfer chamber without intersecting any walls (or other parts) of the transfer chamber. If the clearance circle intersects the transfer chamber, said part of the robot arm system that defines the clearance circle may collide with the transfer chamber during rotation.

[0193] To aid in the following discussion, Fig. 49 is provided showing two top views of an exemplary robotic arm system in a transfer chamber adjacent to the QSM. In the left image, the robotic arms are all in a retracted state, while the right image shows a pair of robotic arms in a far-extended state. Various parameters referenced below are shown in Fig. 49, such as the clearance circles discussed above.

[0194] The various arm links and end effectors of a robot arm system (and the wafers they may support) must fit within a clearance circle in a retracted state. Thus, the clearance circle generally serves to limit the maximum size of such components, with the practical effect of limiting the maximum reach of such a robot arm system. In some such robot arm system implementations, the robot arm links may be designed to have a maximum reach (far extension distance) in a far extended state that is greater than or equal to the diameter of the clearance circle, e.g., 0%, up to 5%, up to 10%, up to 15%, up to 20% greater than the diameter of the clearance circle.

[0195] Another geometric characteristic of some such robot arm systems may be defined by a first reference circle and a second reference circle. The first reference circle may be centered on the axis of rotation of the fuselage unit and may be defined by an edge portion of a wafer supported by the robot arm system (when used to transfer the wafer). The edge portion of the wafer is the furthest from the center of rotation of the fuselage unit when the robot arm system is in a retracted state. The second reference circle may also be centered on the axis of rotation of the fuselage unit and may be defined by an end of an end effector support arm. The end of the end effector support arm is the furthest from the center of rotation of the fuselage unit. One or the other of the first reference circle and the second reference circle, or both of them, may be co-radius with the clearance circle, as the case may be. In some implementations, the first and second reference circles may be within 5%, 4%, 3%, 2%, or 1% of each other in diameter (e.g., if the diameter of the first reference circle is 1 unit, the diameter of the second reference circle may be 1.05 units or 0.95 units (or therebetween)). In some such implementations, at least one robot arm on each side of the fuselage unit may be configured such that each edge portion of the wafer supported by that robot arm (when used to transfer the wafer) defines a corresponding first reference circle centered on the rotation axis of the fuselage unit. The edge portion of the wafer is the portion furthest from the center of rotation of the fuselage unit when the robot arm system is in a retracted state. Furthermore, said at least one robot arm on each side of the fuselage unit may be further configured such that an end of an end effector support arm of that robot arm defines a corresponding second reference circle centered on the rotation axis of the fuselage unit. The end of the end effector support arm is furthest from the center of rotation of the fuselage unit. In such implementations, the at least two first reference circles and the at least two second reference circles may all have diameters within 5% or less, 4% or less, 3% or less, 2% or less, or 1% of each other.By configuring the end effector and end effector support arm in such a manner (e.g., so that when the robot arm is in a retracted state, the wafer supported by it is the same distance away from the center of rotation of the torso unit as the outermost edge or face of the end effector support arm, or approximately the same distance), the length of the end effector support arm can maximize the available space within the clearance circle, thereby allowing the end effector support arm to have a sufficient length to provide the necessary reach to enable the robot arm system to reach the remote seat within the QSM.

[0196] Yet another feature related to the clearance circle of a robot arm system, such as the robot arm systems discussed herein, is the ratio of the amount of extension such a robot arm is configured to provide to the diameter of the clearance circle in the stowed state. In some such implementations, such a robot arm system may be configured to be extended from a position in a retracted state by an amount greater than the diameter of the clearance circle in a far-extended state. In some cases, the amount such an arm may extend when transitioning from a retracted state to a far-extended state may be as much as 105% or more, 110% or more, or 115% or more of the diameter of the clearance circle. In some such implementations, the entirety of the revolute joint connecting the first link of the robot arm to the second link in the far-extended state may be located entirely outside the clearance circle. Such a feature may enable the robot arm to have a greater amount of reach in the far-extended state, which may facilitate reaching the far seat in the QSM.

[0197] Another feature of some robotic arm systems discussed herein is that the arm links of such robotic arm systems may be belt-driven systems. Belt-driven systems are capable of larger angular displacements than, for example, parallel-link driven arm systems. For example, in some such implementations featuring a first link pivotally connected to a torso unit and a second link pivotally connected to the first link and to an end effector support arm, the first link and the second link may be driven to rotate relative to each other by a total angle of α+β greater than 180° (e.g., greater than 200°). Similarly, the first link may be rotatable relative to the torso unit by an angle of γ greater than 90° (e.g., greater than 100°). Such a large rotation angle may allow such a robotic arm to be extendable much more than a robotic arm having a smaller angular motion capability.

[0198] Another feature of some robot arm systems discussed herein is that the axes of rotation of the revolute joints that pivotally couple the first link to the fuselage unit may all be located between a first and a second reference plane when such robot arm system is in a stowed state. The first and second reference planes may be parallel to each other. The first reference plane is coincident with and parallel to the axis of rotation of the fuselage unit. The second reference plane passes through a location of the end effector that coincides with the center of the wafer as it is being transferred by the end effector. Thus, the axis of rotation of such revolute joints may be considered to be "forward" of the center of rotation of the fuselage unit with respect to a perspective through the axis of rotation of the fuselage unit and in the direction along which the robot arm can extend. By configuring such an arm with such an offset, the length of the first and second links may be increased, thus allowing the end effector support arm to move more in response to the rotation of the first and second links.

[0199] Yet another feature of some robotic arm systems discussed herein is that a first length of the end effector support arm and the end effector may be greater than a second length representing the sum of the lengths. The first length is measured from an axis of rotation about which the end effector support arm rotates relative to the second link of the robotic arm to a position that coincides with the center of the wafer when the wafer is supported by the end effector. The second length is measured between the centers of rotation of each of the first link and the second link of the robotic arm. In some such implementations, the first length may be 5% or more greater than the second length. Such a feature may further facilitate an increased reach of such robotic arm systems.

[0200] As mentioned above, the robotic arm system discussed herein may be controlled by a controller. In some such implementations, the controller may be part of a system, which may include or be part of the examples described above. Such a system may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics to control the operation of the electronics before, during, and after processing of the semiconductor wafer or substrate. The electronics may be referred to as a "controller" that may control various parts or sub-parts 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 type of system. Such processes may include delivery of process gases, temperature settings (e.g., heating and / or cooling), light source controls for radiant heating, pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer loading and unloading to and from tools or chambers, and wafer loading and unloading to and from other transport tools and / or load locks connected or coupled to a particular system.

[0201] In general, a controller may be defined as an electronic device having various integrated circuits, logic, memory devices, and / or software that store computer-executable instructions, receive computer-executable instructions, issue computer-executable instructions, execute computer-executable instructions, control operations, enable cleaning operations, enable end-point metrology, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various personalizations (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon oxides, surfaces, circuits, and / or wafer dies.

[0202] In some implementations, the controller may be part of or coupled to a computer that is integrated, coupled, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or be all or part of a fab host computer system, thereby enabling remote access of wafer processing. The computer may enable remote access to the system to monitor the current progress of a fabrication operation, review the history of past fabrication operations, review trends or performance metrics from multiple fabrication operations, modify parameters of a current process, set processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows for input or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specifies parameters for each processing step that is performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed or the type of tool that the controller is configured to couple to or control. Thus, as discussed above, the controller may be distributed, such as by including one or more separate controllers networked together and working toward a common purpose, such as the processes and controls described herein. An example of a controller distributed for such purposes includes one or more integrated circuits on the chamber that are located remotely (such as at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperatively control the processes on the chamber.

[0203] Examples of systems include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch 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 may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0204] As discussed above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool parts, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used for material transport to and from containers of wafers to tool locations and / or load ports within a semiconductor manufacturing factory. In particular, the controller may be configured to cause the robotic arm systems discussed herein, as well as lift pin mechanisms for the pedestals, to undergo operations as described herein, and in particular with respect to Figures 23-44.

[0205] For example, when used in this disclosure and claims, the order indicators (a), (b), (c)... or (1), (2), (3), etc., are not to be understood as referring to any particular order or sequence, except to the extent such order or sequence is expressly indicated. For example, when there are three steps labeled (i), (ii), and (iii), it is to be understood that these steps may be performed in any order (or may be performed simultaneously, unless specifically contraindicated), unless otherwise indicated. For example, if step (ii) involves the manipulation of an element produced in step (i), then step (ii) may be considered to occur at some point after step (i). Similarly, if step (i) involves the manipulation of an element produced in step (ii), then it is to be understood that the opposite is true. It should also be understood that the use of the ordinal designator "first", e.g., "first item" herein should not be read as implicitly or inherently suggesting that a "second" instance, e.g., "second item", is necessarily present.

[0206] It should be understood that phrases such as "for each <item> of one or more <items>," "for each <item> of one or more <items>," as used herein, include both single and multiple items, i.e., "for each" is used in the sense that it is used in programming languages ​​to refer to each item of any population of referenced items. For example, if the population of referenced items is a single item, then "each" refers only to that single item (notwithstanding the fact that dictionary definitions of "each" often define the term to refer to "one of two or more") and does not mean that there must be at least two of those items. Similarly, the terms "set" or "subset" should not be considered as necessarily including a plurality of items per se, and it will be understood that a set or subset can include only one member or multiple members (unless the context implies otherwise).

[0207] The terms "about," "approximately," "substantially," "nominal," and the like, when used in reference to a quantity or similar quantifiable attribute, unless otherwise indicated, should be understood to include values ​​within ±10% of the specified value or relationship (including the actual value or relationship specified).

[0208] The term "between" is used herein, and when used in conjunction with a range of values, should be understood to include the beginning and ending values ​​of the range, unless otherwise indicated. For example, between 1 and 5 should be understood to include the numbers 1, 2, 3, 4, and 5, as well as the numbers 2, 3, and 4.

[0209] The term "transitionable," as used, will be understood to refer to a device or mechanism that is specifically configured to be transitioned between two or more states or configurations. For example, a door may be transitionable between an open state or configuration and a closed state or configuration.

[0210] It is understood that the examples and embodiments described herein are for illustrative purposes only, and various modifications or changes in light of them will be suggested to those skilled in the art. Various details have been omitted for clarity, but various design alternatives can be realized. Therefore, the present examples should be considered as illustrative and not restrictive, and the present disclosure is not limited to the details described herein, and may be modified within the scope of the present disclosure.

[0211] While the above disclosure focuses on one or more particular exemplary implementations, it should be understood that it is not limited to only the discussed examples but may also apply to similar variations and mechanisms, and such similar variations and mechanisms are also considered to be within the scope of the present disclosure.

[0212] It should be further understood that the present disclosure encompasses at least the following non-exclusive list of implementations:

[0213] Implementation 1: The system includes a base, a fuselage unit pivotally connected to the base such that the fuselage unit is pivotable relative to the base about an axis of primary rotation, a pair of first robotic arms supported by the fuselage unit, and a pair of second robotic arms supported by the fuselage unit. Each of the first robotic arms is configured to transition between at least a first retracted state, a first near-extended state, and a first far-extended state. A first distal position of each first robotic arm is closer to the axis of primary rotation when the first robotic arm is in the first retracted state than when the first robotic arm is in the first near-extended state, and the first distal position is furthest from the axis of primary rotation when the first robotic arm is in the first far-extended state. The first distal position of each first robotic arm is closer to the axis of primary rotation when the first robotic arm is in the first near-extended state than when the first robotic arm is in the first far-extended state. Each of the second robotic arms is configured to transition between at least a second retracted state, a second near-extended state, and a second far-extended state. The second distal position of each second robotic arm is closer to the axis of primary rotation when the second robotic arm is in the second retracted state than when the second robotic arm is in the second near-extended state, and the second distal position is furthest from the axis of primary rotation when the second robotic arm is in the second far-extended state. The second distal position of each second robotic arm is closer to the axis of primary rotation when the second robotic arm is in the second near-extended state than when the second robotic arm is in the second far-extended state.

[0214] Implementation 2: The system of implementation 1, wherein each of the first robot arms is configured to support two wafers in a top-bottom configuration, one of the two wafers being centered on a corresponding upper first location fixed relative to a portion of the first robot arm configured to support the two wafers, and the other of the two wafers being centered on a corresponding lower first location fixed relative to a portion of the first robot arm configured to support the two wafers. The upper first locations are each nominally centered above a different first corner of the first square region when the first robot arm is in at least one of a first near-extension state or a first far-extension state. The lower first locations are each nominally centered above a different second corner of the first square region when the first robot arm is in at least the other of the first near-extension state or the first far-extension state, and the second corner of the first square region is different from the first corner of the first square region. Each of the second robot arms is configured to support two wafers in an up-down configuration, one of the two wafers being centered on a corresponding upper second location fixed relative to a portion of the second robot arm configured to support the two wafers, and the other of the two wafers being centered on a corresponding lower second location fixed relative to a portion of the second robot arm configured to support the two wafers. The upper second locations are each nominally centered above a different first corner of the second square region when the second robot arm is in at least one of the second near extension state or the second far extension state. The lower second locations are each nominally centered above a different second corner of the second square region when the second robot arm is in at least the other of the second near extension state or the second far extension state, and the second corner of the second square region is different from the first corner of the second square region. The first square region and the second square region are co-located and have the same orientation and size.

[0215] Implementation 3: The system of implementation 2, wherein the upper first position and the lower first position for at least one of the first robotic arms are both located along a corresponding common vertical axis.

[0216] Implementation 4: The system of implementation 2, wherein the upper first position and the lower first position for at least one of the first robot arms are both located along different, non-coaxial vertical axes.

[0217] Implementation 5: The system of any one of implementations 1 to 4, wherein for each first robot arm, the first robot arm has a corresponding first end effector support arm and a plurality of corresponding first arm links. The corresponding first arm link for the first robot arm includes a corresponding first base link and one or more corresponding first intermediate arm links. The corresponding first base link for the first robot arm is pivotally connected to the fuselage unit such that the corresponding first base link for the first robot arm is pivotable relative to the fuselage unit about a corresponding first axis. The corresponding first base link for the first robot arm supports one or more corresponding first intermediate arm links, and the one or more corresponding first base links for the first robot arm support a corresponding first end effector support arm for the first robot arm. For each second robot arm, the second robot arm has a corresponding second end effector support arm and a plurality of corresponding second arm links. The corresponding second arm link for the second robot arm includes a corresponding second base link and one or more corresponding second intermediate arm links. The corresponding second base link for the second robot arm is pivotally connected to the fuselage unit such that the corresponding second base link for the second robot arm is pivotable relative to the fuselage unit about a corresponding second axis. The corresponding second base link for the second robot arm supports one or more corresponding second intermediate arm links, and the one or more corresponding second base links for the second robot arm support a corresponding second end effector support arm for the second robot arm. The first axis and the second axis are all substantially parallel to one another. The first axes are spaced apart from one another in a direction perpendicular to the first axis. The second axes are spaced apart from one another in a direction perpendicular to the second axis.

[0218] Implementation 6: The system of implementation 5, wherein each first robotic arm is configured to translate a corresponding first end effector support arm for the first robotic arm along a corresponding translation axis relative to the fuselage unit in response at least in part to a rotation of a first base link for the first robotic arm relative to the fuselage unit. Each second robotic arm is configured to translate a corresponding second end effector support arm for the second robotic arm along a corresponding translation axis relative to the fuselage unit in response at least in part to a rotation of a second base link for the second robotic arm relative to the fuselage unit. The translation axes of the first robotic arm and the second robotic arm are all substantially parallel to each other.

[0219] Implementation 7: The system of any of Implementations 5 or 6, wherein the first arm links of the plurality of corresponding first arm links for each of the first robot arms are configured to rotate relative to one another about corresponding axes of rotation substantially parallel to the first axis. The first end effector support arm of each of the first robot arms is configured to rotate relative to a corresponding first intermediate arm link of the first robot arm that is closest to the first end effector support arm, the corresponding axis of rotation being substantially parallel to the first axis. The second arm links of the plurality of corresponding second arm links for each of the second robot arms are configured to rotate relative to one another about corresponding axes of rotation substantially parallel to the second axis. The second end effector support arm of each of the second robot arms is configured to rotate relative to a corresponding second intermediate arm link of the second robot arm that is closest to the second end effector support arm, the corresponding axis of rotation being substantially parallel to the second axis.

[0220] Implementation 8: The system of implementation 7, wherein each first robotic arm has two corresponding first arm links and each second robotic arm has two corresponding second arm links.

[0221] Implementation 9: The system of implementation 8, wherein each of the first base links has a corresponding first base link length defined by a distance between a first axis and a corresponding axis of rotation about which the corresponding first intermediate arm link is configured to rotate relative to the first base link. Each of the first intermediate arm links has a corresponding first intermediate arm link length defined by a distance between a corresponding axis of rotation about which the first intermediate arm link is configured to rotate relative to the corresponding first base link and a corresponding axis of rotation about which the corresponding first end effector support arm is configured to rotate relative to the first intermediate arm link. Each of the second base links has a corresponding second base link length defined by a distance between a second axis and a corresponding axis of rotation about which the corresponding second intermediate arm link is configured to rotate relative to the second base link. Each of the second intermediate arm links has a corresponding second intermediate arm link length defined by a distance between a corresponding axis of rotation about which the second intermediate arm link is configured to rotate relative to the corresponding second base link and a corresponding axis of rotation about which the corresponding second end effector support arm is configured to rotate relative to the second intermediate arm link. The first base link length and the first intermediate arm link length for at least one of the first robotic arms are equal to one another. The second base link length and the second intermediate arm link length for at least one of the second robotic arms are equal to one another.

[0222] Implementation 10: The system of implementation 9, wherein a first base link length and a first intermediate arm link length for at least one of the first robotic arms are equal to one another. A second base link length and a second intermediate arm link length for at least one of the second robotic arms are equal to one another. The first base link length is longer than the second base link length.

[0223] Implementation form 11: A system of implementation form 9, wherein a first base link length and a first intermediate arm link length for at least one of the first robot arms are equal to each other and are also equal to a second base link length and a second intermediate arm link length for at least one of the second robot arms.

[0224] Implementation 12: The system of implementation 9, wherein the first base link length and the first mid-arm link length for both of the first robotic arms are equal, and the second base link length and the second mid-arm link length for both of the second robotic arms are equal.

[0225] Implementation 13: A system of implementation 12, wherein the first base link length and first intermediate arm link length for both of the first robotic arms, and the second base link length and second intermediate arm link length for both of the second robotic arms are all equal.

[0226] Implementation 14: The system of any of implementations 11 or 13, wherein the first base link length, the second base link length, the first intermediate arm link length, and the second intermediate arm link length for the first pair of the first robot arm and the second robot arm located on a common side of the reference plane of the fuselage unit are all the same, and the reference plane is on the same plane as the main rotation axis and is disposed between both first robot arms. The first axis and the second axis of the first pair of the first robot arm and the second robot arm are coaxial. The first base link of the first robot arm of the first pair of the first robot arm and the second robot arm is fixed in space relative to the corresponding first inner bypass section. The first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm is fixed in space relative to the corresponding first outer bypass section. The first inner bypass section includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is fixedly connected to a first base link of a first robot arm of the first pair of the first robot arm and the second robot arm. The corresponding second portion is pivotally connected to a first intermediate arm link of a first robot arm of the first pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the first inner bypass portion, and is positioned such that the corresponding bridge portion of the first inner bypass portion is farther from a first axis of a first robot arm of the first pair of the first robot arm and the second robot arm than a corresponding axis of rotation about which the corresponding first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm is configured to rotate relative to the first base link of the first robot arm of the first pair of the first robot arm and the second robot arm. The first outer bypass portion includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is pivotally connected to a first base link of a first robotic arm of a first pair of the first and second robotic arms.The corresponding second portion is fixedly connected to the first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the first outer bypass portion and is positioned such that the corresponding bridge portion of the first outer bypass portion is farther from the first axis of the first robot arm of the first pair of the first robot arm and the second robot arm than the corresponding bridge portion of the first inner bypass portion when the first robot arm of the first pair of the first robot arm and the second robot arm is in the first contracted state.

[0227] Implementation 15: The system of implementation 14, wherein the first base link length, the second base link length, the first intermediate arm link length, and the second intermediate arm link length for the second pair of the first robot arm and the second robot arm located on the opposite side of the reference plane of the fuselage unit are all the same. The first axis and the second axis of the second pair of the first robot arm and the second robot arm are coaxial. The first base link of the first robot arm of the second pair of the first robot arm and the second robot arm is fixed in space with respect to the corresponding second inner bypass section. The first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm is fixed in space with respect to the corresponding second outer bypass section. The second inner bypass section includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is fixedly connected to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm. The corresponding second portion is pivotally connected to the first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm. The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the second inner bypass portion, and is positioned such that the corresponding bridge portion of the second inner bypass portion is farther from the first axis of the first robot arm of the second pair of the first robot arm and the second robot arm than the corresponding axis of rotation about which the corresponding first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm is configured to rotate relative to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm. The second outer bypass portion includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion. The corresponding first portion is pivotally connected to a first base link of a first robot arm of the second pair of the first robot arm and the second robot arm, and the corresponding second portion is fixedly connected to a first middle arm link of a first robot arm of the second pair of the first robot arm and the second robot arm.The corresponding bridge portion spans between the corresponding first portion and the corresponding second portion of the second outer bypass portion and is positioned such that when the first robot arm of the second pair of the first robot arm and the second robot arm is in the first contracted state, the corresponding bridge portion of the second outer bypass portion is farther from the first axis of the first robot arm of the second pair of the first robot arm and the second robot arm than the corresponding bridge portion of the second inner bypass portion.

[0228] Implementation 16: A system of implementation 15, wherein the first pair of the first robot arm and the second robot arm and the second pair of the first robot arm and the second robot arm are positioned symmetrically with respect to a reference plane.

[0229] Implementation 17: A system of implementation 9 or any one of implementations 11 to 13, wherein the first axes are spaced apart from each other by a distance different from the distance between the second axes.

[0230] Implementation 18: The system of any one of implementations 1 to 17, wherein each of the first end effector support arms has a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion. The corresponding first portion and the corresponding second portion of each of the first end effector support arms extend along parallel axes, the parallel axes being offset from one another in a direction perpendicular to the parallel axes. The corresponding offset jog portion of each of the first end effector support arms spans between the corresponding first portion and the corresponding second portion of the first end effector support arm.

[0231] Implementation 19: The system of implementation 18, wherein each of the second end effector support arms has a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion. The corresponding first portion and the corresponding second portion of each of the second end effector support arms extend along parallel axes that are offset from one another in a direction perpendicular to the parallel axes. The corresponding offset jog portion of each of the second end effector support arms spans between the corresponding first portion and the corresponding second portion of the second end effector support arm.

[0232] Implementation 20: The system of any one of implementations 1 to 19, further comprising a transfer chamber. The base is fixedly mounted relative to the transfer chamber. The fuselage unit is at least partially located within the transfer chamber. The first robot arm is fully located within the transfer chamber when in the first retracted state. The second robot arm is fully located within the transfer chamber when in the second retracted state. The fuselage unit, together with the first robot arm and the second robot arm, is rotatable within the transfer chamber by at least 90° relative to the transfer chamber when the first robot arm is in the first retracted state and the second robot arm is in the second retracted state.

[0233] Implementation 21: The system of implementation 20, further comprising one or more multi-station processing chambers. Each multi-station processing chamber is connected to the transfer chamber by one or more corresponding wafer transfer passages. Each multi-station processing chamber has a corresponding pair of near pedestals close to the transfer chamber and a corresponding pair of far pedestals far from the transfer chamber. The first robot arm is configured to transfer a wafer to the corresponding pair of near pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the first robot arm is aligned with one or more corresponding wafer transfer passages of the multi-station processing chambers and the first robot arm is in a first near extension state. The first robot arm is configured to transfer a wafer to the corresponding pair of far pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the first robot arm is aligned with one or more corresponding wafer transfer passages of the multi-station processing chambers and the first robot arm is in a first far extension state. The second robot arm is configured to transfer the wafer to the corresponding pair of near pedestals of each of the multi-station processing chambers when the body unit is rotated so that the second robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the second robot arm is in the second near-extended state. The second robot arm is configured to transfer the wafer to the corresponding pair of far pedestals of each of the multi-station processing chambers when the body unit is rotated so that the second robot arm is aligned with one or more corresponding wafer transfer paths of the multi-station processing chambers and the second robot arm is in the second far-extended state.

[0234] Implementation 22: The system of implementation 21, wherein each multi-station processing chamber is a quad-station module.

[0235] Implementation 23: The system of any of Implementations 21 or 22, further comprising one or more active wafer centering sensor systems. Each active wafer centering sensor system is configured to obtain a center position measurement of a wafer being transported through one of the wafer transport paths by the first robot arm and / or the second robot arm.

[0236] Implementation 24: The system of any one of implementations 1 to 22, further comprising a controller including one or more memory devices and one or more processors. The one or more memory devices store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to a) transition the first robot arm from a first retracted state to a first far-extended state with each first robot arm supporting a pair of wafers; b) leaving the first robot arm in the first far-extended state while a lower wafer supported by the first robot arm is lifted from the first robot arm; c) transition the first robot arm from the first far-extended state to a first near-extended state after (b) and while each first robot arm supports a wafer of the pair of wafers supported by the first robot arm that was not removed in (b); d) leaving the first robot arm in the first near-extended state while an upper wafer supported by the first robot arm is lifted from the first robot arm; and e) transition the first robot arm from the first near-extended state to a first retracted state after (d) and while each first robot arm is not supporting a wafer.

[0237] Implementation 25: The system of Implementation 24, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to sequentially: rotate the torso unit, extend or retract at least one of the first robot arms, or rotate the torso unit and extend or retract at least one of the first robot arms to center one of the wafers lifted from the first robot arm during (b) on a first far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the first robot arms, or rotate the torso unit and extend or retract at least the other of the first robot arms to center the other of the wafers lifted from the first robot arm during (b) on a second far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b).

[0238] Implementation 26: The system of Implementation 24, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust by one of the first robot arms its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center one of the wafers lifted from the first robot arms during (b) on a first far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b), and cause the other of the first robot arms to adjust its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center the other of the wafers lifted from the first robot arms during (b) on a second far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b).

[0239] Implementation 27: The system of Implementation 24, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust an amount of extension by one of the first robot arms, an amount of rotation relative to the torso unit, or an amount of extension and an amount of rotation relative to the torso unit to center one of the wafers lifted from the first robot arm during (b) on a first far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the first robot arms, or rotate the torso unit and extend or retract at least the other of the first robot arms, to center the other of the wafers lifted from the first robot arm during (b) on a second far target position prior to lifting the wafer from the first robot arm supporting the wafer at the beginning of (b).

[0240] Implementation 28: The system of any one of implementations 24 to 26, wherein the one or more memory devices further store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to: f) transition the first robot arms from the first retracted state to a first near extended state while each of the first robot arms is not supporting a wafer; g) leave the first robot arms in the first near extended state while each of the first robot arms has a corresponding wafer disposed thereon; h) transition the first robot arms from the first near extended state to a first far extended state after (g) and while each of the first robot arms supports a single wafer disposed thereon in (g); i) leave the first robot arms in the first far extended state while each of the first robot arms has another wafer disposed thereon and in a position below the wafer already supported by the first robot arm; and j) transition the first robot arms from the first far extended state to a first retracted state after (i) and while each of the first robot arms supports two wafers disposed thereon.

[0241] Implementation 29: The system of any one of implementations 24 to 28, wherein the one or more memory devices further store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to 1) transition the second robot arm from the second retracted state to a second far-extended state with each second robot arm supporting a pair of wafers; 2) leave the second robot arm in the second far-extended state while a lower wafer supported by the second robot arm is lifted from the second robot arm; 3) transition the second robot arm from the second far-extended state to a second near-extended state after (2) and while each second robot arm supports a wafer of the pair of wafers supported by the second robot arm that was not removed in (2); 4) leave the second robot arm in the second near-extended state while an upper wafer supported by the second robot arm is lifted from the second robot arm; and 5) transition the second robot arm from the second near-extended state to a second retracted length state after (4) and while each second robot arm is not supporting a wafer.

[0242] Implementation 30: The system of implementation 29, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to sequentially: rotate the torso unit, extend or retract at least one of the second robot arms, or rotate the torso unit and extend or retract at least one of the second robot arms to center one of the wafers lifted from the second robot arm during (2) on a first far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2), and rotate the torso unit, extend or retract at least the other of the second robot arms, or rotate the torso unit and extend or retract at least the other of the second robot arms, to center the other of the wafers lifted from the second robot arm during (2) on a second far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0243] Implementation 31: The system of Implementation 29, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust an amount of extension, an amount of rotation relative to the torso unit, or an amount of extension and an amount of rotation relative to the torso unit by one of the second robot arms to center one of the wafers lifted from the second robot arm during (2) over the first far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0244] The other of the second robot arms adjusts its amount of extension, its amount of rotation relative to the body unit, or its amount of extension and its amount of rotation relative to the body unit to center the other of the wafers lifted from the second robot arm during (2) over a second far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0245] Implementation 32: The system of Implementation 24, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust an amount of extension by one of the second robot arms, an amount of rotation relative to the torso unit, or an amount of extension and an amount of rotation relative to the torso unit, to center one of the wafers lifted from the second robot arm during (2) on a first far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2), and rotate the torso unit, extend or retract at least the other of the second robot arms, or rotate the torso unit and extend or retract at least the other of the second robot arms, to center the other of the wafers lifted from the second robot arm during (2) on a second far target position prior to lifting the wafer from the second robot arm supporting the wafer at the beginning of (2).

[0246] Implementation 33: A system of either implementation 24 or implementation 25, wherein the one or more memory devices further store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to: 6) transition the second robot arms from the second retracted state to a second near extended state while each second robot arm is not supporting a wafer; 7) leave the second robot arms in the second near extended state while each second robot arm has a corresponding wafer disposed thereon; 8) transition the second robot arms from the second near extended state to a second far extended state after (g) and while each second robot arm supports a single wafer disposed thereon in (g); 9) leave the second robot arms in the second far extended state while each second robot arm has another wafer disposed thereon and in a position below the wafer already supported by the second robot arm; and 10) transition the second robot arms from the second far extended state to a second retracted state after (9) and while each second robot arm supports two wafers disposed thereon.

[0247] Implementation 34: A system includes a base, a fuselage unit pivotally connected to the base such that the fuselage unit is pivotable relative to the base about an axis of primary rotation, and a pair of robotic arms supported by the fuselage unit. Each of the robotic arms is configured to transition between at least a retracted state, a near-extended state, and a far-extended state. A distal position of each robotic arm is closer to the axis of primary rotation when the robotic arm is in the retracted state than when the robotic arm is in the near-extended state, and the distal position is furthest from the axis of primary rotation when the robotic arm is in the far-extended state. A distal position of each robotic arm is closer to the axis of primary rotation when the robotic arm is in the near-extended state than when the robotic arm is in the far-extended state.

[0248] Implementation 35: The system of implementation 34, wherein each of the robot arms is configured to support two wafers in an up-down configuration, one of the two wafers being centered on a corresponding upper location fixed relative to a portion of the robot arm configured to support the two wafers, and the other of the two wafers being centered on a corresponding lower location fixed relative to a portion of the robot arm configured to support the two wafers. The upper locations are each nominally centered above a different first corner of the square region when the robot arm is in at least one of a near extension state or a far extension state. The lower locations are each nominally centered above a different second corner of the square region when the robot arm is in at least the other of a near extension state or a far extension state, and the second corner of the square region is different from the first corner of the square region.

[0249] Implementation 36: The system of implementation 35, wherein the upper and lower positions for at least one of the robotic arms are both located along a corresponding common vertical axis.

[0250] Implementation 37: The system of implementation 35, wherein the upper and lower positions for at least one of the robotic arms are both located along different, non-coaxial vertical axes.

[0251] Implementation 38: The system of any one of implementations 34 to 37, wherein, for each robot arm, the robot arm has a corresponding end effector support arm and a plurality of corresponding arm links. The corresponding arm links for the robot arm include a corresponding base link and one or more corresponding intermediate arm links. The corresponding base links for the robot arm are pivotally connected to the fuselage unit such that the corresponding base links for the robot arm are pivotable relative to the fuselage unit about a corresponding first axis. The corresponding base links for the robot arms support one or more corresponding intermediate arm links, and the one or more corresponding base links for the robot arms support corresponding end effector support arms for the robot arms. The first axes are substantially parallel to each other and spaced apart from each other in a direction perpendicular to the first axis.

[0252] Implementation 39: The system of implementation 38, wherein each robotic arm is configured to translate a corresponding end effector support arm for the robotic arm along a corresponding translation axis relative to the fuselage unit in response at least in part to a rotation of the base link for the robotic arm relative to the fuselage unit. The translation axes of the robotic arms are substantially parallel to one another.

[0253] Implementation 40: The system of any of implementations 38 or 39, wherein the arm links in the plurality of corresponding arm links for each of the robot arms are configured to rotate relative to one another about corresponding axes of rotation that are substantially parallel to the first axis. The end effector support arm for each of the robot arms is configured to rotate about a corresponding axis of rotation relative to a corresponding intermediate arm link of the robot arm that is closest to the end effector support arm, the corresponding axis of rotation being substantially parallel to the first axis.

[0254] Implementation 41: The system of implementation 40, where each robot arm has two corresponding arm links.

[0255] Implementation 42: The system of implementation 41, wherein each of the base links has a corresponding base link length defined by a distance between the first axis and a corresponding axis of rotation about which the corresponding intermediate arm link is configured to rotate relative to the base link. Each of the intermediate arm links has a corresponding intermediate arm link length defined by a distance between a corresponding axis of rotation about which the intermediate arm link is configured to rotate relative to the corresponding base link and a corresponding axis of rotation about which the corresponding end effector support arm is configured to rotate relative to the intermediate arm link. The base link length and the intermediate arm link length are equal to one another.

[0256] Implementation 43: A system of any one of implementations 34 to 42, in which the robot arm is positioned symmetrically with respect to a reference plane.

[0257] Implementation 44: The system of any one of implementations 34 to 43, wherein each of the end effector support arms has a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion. The corresponding first portion and the corresponding second portion of each of the end effector support arms extend along parallel axes that are offset from one another perpendicularly relative to the parallel axes. The corresponding offset jog portion of each of the end effector support arms spans between the corresponding first portion and the corresponding second portion of the end effector support arm.

[0258] Implementation 45: The system of any one of implementations 34 to 44, further comprising a transfer chamber. The base is fixedly mounted relative to the transfer chamber. The fuselage unit is at least partially located within the transfer chamber. The robot arm is located completely within the transfer chamber when in a retracted state. The fuselage unit is rotatable within the transfer chamber together with the robot arm by at least 90° relative to the transfer chamber when the robot arm is in a retracted state.

[0259] Implementation 46: The system of implementation 45, further comprising one or more multi-station processing chambers. Each multi-station processing chamber is connected to the transfer chamber by one or more corresponding wafer transfer passages. Each multi-station processing chamber has a corresponding pair of near pedestals close to the transfer chamber and a corresponding pair of far pedestals far from the transfer chamber. The robot arm is configured to transfer a wafer to the corresponding pair of near pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the robot arm is aligned with one or more corresponding wafer transfer passages of the multi-station processing chambers and the robot arm is in a near extension state. The robot arm is configured to transfer a wafer to the corresponding pair of far pedestals of each of the multi-station processing chambers when the torso unit is rotated so that the robot arm is aligned with one or more corresponding wafer transfer passages of the multi-station processing chambers and the robot arm is in a far extension state.

[0260] Implementation 47: The system of implementation 46, wherein each multi-station processing chamber is a quad-station module.

[0261] Implementation 48: The system of any of implementations 46 or 47, further comprising one or more active wafer centering sensor systems. Each active wafer centering sensor system is configured to obtain a center position measurement of a wafer transported by the robotic arm through one of the wafer transport paths.

[0262] Implementation 49: The system of any one of implementations 34 to 47, further comprising a controller including one or more memory devices and one or more processors. The one or more memory devices store computer-executable instructions. The computer-executable instructions, when executed by the one or more processors, cause the one or more processors to: a) transition the robot arms from a retracted state to a far-extended state with each robot arm supporting a pair of wafers; b) leave the robot arms in the far-extended state while a lower wafer supported by the robot arms is lifted from the robot arms; c) transition the robot arms from the far-extended state to a near-extended state after (b) and with each robot arm supporting a wafer of the pair of wafers supported by the robot arms that was not removed in (b); d) leave the robot arms in the near-extended state while an upper wafer supported by the robot arm is lifted from the robot arms; and e) transition the robot arms from the near-extended state to a retracted state after (d) and with each robot arm not supporting a wafer.

[0263] Implementation 50: The system of implementation 49, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to sequentially: rotate the torso unit, extend or retract at least one of the robot arms, or rotate the torso unit and extend or retract at least one of the robot arms to center one of the wafers lifted from the robot arms during (b) on a first far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the robot arms, or rotate the torso unit and extend or retract at least the other of the robot arms, to center the other of the wafers lifted from the robot arms during (b) on a second far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b).

[0264] Implementation 51: The system of implementation 49, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust by one of the robot arms its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center one of the wafers lifted from the robot arms during (b) on a first far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b), and cause the other of the robot arms to adjust its amount of extension, its amount of rotation relative to the torso unit, or its amount of extension and its amount of rotation relative to the torso unit to center the other of the wafers lifted from the robot arms during (b) on a second far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b).

[0265] Implementation 52: The system of implementation 49, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to, at least partially simultaneously, adjust an amount of extension by one of the robot arms, an amount of rotation relative to the torso unit, or an amount of extension and an amount of rotation relative to the torso unit to center one of the wafers lifted from the robot arms during (b) on a first far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b), and rotate the torso unit, extend or retract at least the other of the robot arms, or rotate the torso unit and extend or retract at least the other of the robot arms, to center the other of the wafers lifted from the robot arms during (b) on a second far target position prior to lifting the wafer from the robot arm supporting the wafer at the beginning of (b).

[0266] Implementation 53: The system of any one of implementations 49 to 52, wherein the one or more memory devices further store computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to: f) transition the robot arms from a retracted state to a near-extended state with each robot arm not supporting a wafer, g) leave the robot arms in the near-extended state while each of the robot arms has a corresponding wafer disposed thereon, h) transition the robot arms from a near-extended state to a far-extended state after (g) and with each robot arm supporting a single wafer disposed thereon in (g), i) leave the robot arms in the far-extended state while each of the robot arms has another wafer disposed thereon and in a position below the wafer already supported by the robot arm, and j) transition the robot arms from a far-extended state to a retracted state after (i) and with each robot arm supporting two wafers disposed thereon.

Claims

1. 1. A system comprising: A base and a fuselage unit pivotally connected to the base such that the fuselage unit is pivotable relative to the base about an axis of primary rotation; a pair of first robot arms supported by the fuselage unit; a pair of second robot arms supported by the fuselage unit; Equipped with each of the first robotic arms is configured to transition between at least a first retracted state, a first near-extended state, and a first far-extended state; a first distal position of each first robotic arm is closer to the axis of primary rotation when the first robotic arm is in the first retracted state than when the first robotic arm is in the first near-extended state, and the first distal position is farthest from the axis of primary rotation when the first robotic arm is in the first far-extended state; the first distal position of each first robotic arm is closer to the axis of primary rotation when the first robotic arm is in the first near-extension state than when the first robotic arm is in the first far-extension state; each of the second robotic arms is configured to transition between at least a second retracted state, a second near-extended state, and a second far-extended state; a second distal position of each second robotic arm is closer to the axis of primary rotation when the second robotic arm is in the second retracted state than when the second robotic arm is in the second near-extended state, and the second distal position is furthest from the axis of primary rotation when the second robotic arm is in the second far-extended state; the second distal position of each second robotic arm is closer to the axis of primary rotation when the second robotic arm is in the second near-extension state than when the second robotic arm is in the second far-extension state.

2. 10. The system of claim 1, each of the first robot arms is configured to support two wafers in an up-and-down configuration, one of the two wafers being centered on a corresponding upper first location fixed relative to a portion of the first robot arm configured to support the two wafers, and the other of the two wafers being centered on a corresponding lower first location fixed relative to the portion of the first robot arm configured to support the two wafers; the upper first locations are each nominally centered above a different first corner of a first square region when the first robotic arm is in at least one of the first near-extension state or the first far-extension state; each of the lower first locations is nominally centered over a different second corner of the first square area when the first robot arm is in at least the other of the first near-extension state or the first far-extension state, the second corner of the first square area being different from the first corner of the first square area; each of the second robot arms is configured to support two wafers in an up-and-down configuration, one of the two wafers being centered on a corresponding upper second location fixed relative to a portion of the second robot arm configured to support the two wafers, and the other of the two wafers being centered on a corresponding lower second location fixed relative to the portion of the second robot arm configured to support the two wafers; the upper second locations are each nominally centered above a different first corner of a second square region when the second robotic arm is in at least one of the second near-extension state or the second far-extension state; each of the lower second positions is nominally centered over a different second corner of the second square area when the second robot arm is in at least the other of the second near-extension state or the second far-extension state, the second corner of the second square area being different from the first corner of the second square area; The system, wherein the first square region and the second square region are co-located, have the same orientation and the same size.

3. 3. The system of claim 2, wherein the upper first position and the lower first position for at least one of the first robotic arms both lie along a corresponding common vertical axis.

4. 3. The system of claim 2, wherein the upper first position and the lower first position for at least one of the first robotic arms are both located along different, non-coaxial vertical axes.

5. 10. The system of claim 1, For each first robotic arm: the first robotic arm has a corresponding first end effector support arm and a plurality of corresponding first arm links, the corresponding first arm links for the first robotic arm including a corresponding first base link and one or more corresponding first intermediate arm links; the corresponding first base link for the first robotic arm is pivotally connected to the fuselage unit such that the corresponding first base link for the first robotic arm is pivotable relative to the fuselage unit about a corresponding first axis; the corresponding first base link for the first robot arm supports the one or more corresponding first intermediate arm links, and the one or more corresponding first base links for the first robot arm supports the corresponding first end effector support arm for the first robot arm; For each second robotic arm: the second robotic arm has a corresponding second end effector support arm and a plurality of corresponding second arm links, the corresponding second arm links for the second robotic arm including a corresponding second base link and one or more corresponding second intermediate arm links; the corresponding second base link for the second robotic arm is pivotally connected to the fuselage unit such that the corresponding second base link for the second robotic arm is pivotable relative to the fuselage unit about a corresponding second axis; the corresponding second base link for the second robot arm supports the one or more corresponding second intermediate arm links, and the one or more corresponding second base links for the second robot arm support the corresponding second end effector support arm for the second robot arm; the first axis and the second axis are all substantially parallel to one another; the first axes are spaced apart from one another in a direction perpendicular to the first axes; The plurality of second axes are spaced apart from one another in a direction perpendicular to the plurality of second axes.

6. 6. The system of claim 5, each first robotic arm configured to translate the corresponding first end effector support arm for the first robotic arm relative to the fuselage unit along a corresponding translation axis at least in part in response to rotation of the first base link for the first robotic arm relative to the fuselage unit; each second robotic arm configured to translate the corresponding second end effector support arm for the second robotic arm relative to the fuselage unit along a corresponding translation axis at least in part in response to a rotation of the second base link for the second robotic arm relative to the fuselage unit; the translational axes of the first robotic arm and the second robotic arm are all substantially parallel to one another.

7. 6. The system of claim 5, the first arm links in the plurality of corresponding first arm links for each of the first robot arms are configured to rotate relative to one another about corresponding axes of rotation that are substantially parallel to the first axis; the first end effector support arm for each of the first robot arms is configured to rotate about a corresponding axis of rotation relative to the corresponding first intermediate arm link of the first robot arm closest to the first end effector support arm, the corresponding axis of rotation being substantially parallel to the first axis; the second arm links in the plurality of corresponding second arm links for each of the second robot arms are configured to rotate relative to one another about corresponding axes of rotation that are substantially parallel to the second axis; the second end effector support arm for each of the second robotic arms is configured to rotate about a corresponding axis of rotation relative to the corresponding second intermediate arm link of the second robotic arm that is closest to the second end effector support arm, the corresponding axis of rotation being substantially parallel to the second axis.

8. 8. The system of claim 7, wherein each first robotic arm has two corresponding first arm links and each second robotic arm has two corresponding second arm links.

9. 9. The system of claim 8, each of the first base links has a corresponding first base link length defined by the distance between the first axis and the corresponding axis of rotation about which the corresponding first intermediate arm link is configured to rotate relative to the first base link; each of the first intermediate arm links has a corresponding first intermediate arm link length defined by the distance between the corresponding axis of rotation about which the first intermediate arm link is configured to rotate relative to the corresponding first base link and the corresponding axis of rotation about which the corresponding first end effector support arm is configured to rotate relative to the first intermediate arm link; each of the second base links has a corresponding second base link length defined by the distance between the second axis and the corresponding axis of rotation about which the corresponding second intermediate arm link is configured to rotate relative to the second base link; each of the second intermediate arm links has a corresponding second intermediate arm link length defined by the distance between the corresponding axis of rotation about which the second intermediate arm link is configured to rotate relative to the corresponding second base link and the corresponding axis of rotation about which the corresponding second end effector support arm is configured to rotate relative to the second intermediate arm link; the first base link length and the first intermediate arm link length for at least one of the first robot arms are equal to each other; the second base link length and the second mid-arm link length for at least one of the second robotic arms are equal to one another.

10. 10. The system of claim 9, the first base link length and the first intermediate arm link length for at least one of the first robot arms are equal to each other; the second base link length and the second intermediate arm link length for at least one of the second robot arms are equal to each other; The first base link length is greater than the second base link length.

11. 10. The system of claim 9, the first base link length and the first intermediate arm link length for at least one of the first robotic arms are equal to each other and to the second base link length and the second intermediate arm link length for at least one of the second robotic arms.

12. 10. The system of claim 9, the first base link length and the first intermediate arm link length for both of the first robot arms are equal; wherein the second base link length and the second mid-arm link length for both of the second robotic arms are equal.

13. 13. The system of claim 12, wherein the first base link length and the first intermediate arm link length for both of the first robotic arms and the second base link length and the second intermediate arm link length for both of the second robotic arms are all equal.

14. 12. The system of claim 11, the first base link length, the second base link length, the first intermediate arm link length, and the second intermediate arm link length for a first pair of the first robot arm and the second robot arm located on a common side of a reference plane of the fuselage unit are all the same, and the reference plane is coplanar with the main rotation axis and is disposed between both of the first robot arms; the first axis and the second axis of the first pair of the first robot arm and the second robot arm are coaxial; the first base link of the first robot arm of the first pair of the first and second robot arms is fixed in space relative to a corresponding first inner bypass section; the first intermediate arm link of the first pair of the first robot arm and the second robot arm is fixed in space relative to a corresponding first outer bypass section; The first inner bypass section includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion, the corresponding first portion being fixedly connected to the first base link of the first robot arm of the first pair of the first robot arm and the second robot arm, the corresponding second portion being pivotally connected to the first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm, and the corresponding bridge portion being pivotally connected to the corresponding first portion and the corresponding second portion of the first inner bypass section. and a first intermediate arm link of the first pair of robot arms of the first and second robot arms is configured to rotate relative to the first base link of the first robot arm of the first pair of robot arms of the first and second robot arms, the first intermediate arm link spanning between the first and second intermediate arm links and the second robot arm such that the corresponding bridge portion of the first inner bypass section is positioned farther from the first axis of rotation of the first robot arm of the first pair of robot arms of the first and second robot arms than the corresponding axis of rotation about which the corresponding first intermediate arm link of the first robot arm of the first pair of robot arms of the first and second robot arms is configured to rotate relative to the first base link of the first robot arm of the first pair of robot arms of the first and second robot arms, the first outer bypass section includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion, the corresponding first portion pivotally connected to the first base link of the first robot arm of the first pair of the first robot arm and the second robot arm, the corresponding second portion fixedly connected to the first intermediate arm link of the first robot arm of the first pair of the first robot arm and the second robot arm, the corresponding bridge portion spanning between the corresponding first portion and the corresponding second portion of the first outer bypass section, and positioned such that the corresponding bridge portion of the first outer bypass section is farther from the first axis of the first robot arm of the first pair of the first robot arm and the second robot arm than the corresponding bridge portion of the first inner bypass section when the first robot arm of the first pair of the first robot arm and the second robot arm is in the first contracted state.

15. 15. The system of claim 14, the first base link length, the second base link length, the first intermediate arm link length, and the second intermediate arm link length for a second pair of the first robot arm and the second robot arm located on the opposite side of the reference plane of the fuselage unit are all the same; the first axis and the second axis of the second pair of the first robot arm and the second robot arm are coaxial; the first base link of the first robot arm of the second pair of the first and second robot arms is fixed in space relative to a corresponding second inner bypass section; the first intermediate arm link of the first robot arm of the second pair of the first and second robot arms is fixed in space relative to a corresponding second outer bypass section; The second inner bypass section includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion, the corresponding first portion being fixedly connected to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm, the corresponding second portion being pivotally connected to the first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm, and the corresponding bridge portion being pivotally connected to the corresponding first portion and the corresponding second portion of the second inner bypass section. and the second inner bypass section is positioned such that the corresponding bridge portion of the second inner bypass section is farther from the first axis of rotation of the first robot arm of the second pair of the first robot arm and the second robot arm than the corresponding axis of rotation about which the corresponding first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm is configured to rotate relative to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm; the second outer bypass section includes a corresponding first portion, a corresponding second portion, and a corresponding bridge portion, the corresponding first portion pivotally connected to the first base link of the first robot arm of the second pair of the first robot arm and the second robot arm, the corresponding second portion fixedly connected to the first intermediate arm link of the first robot arm of the second pair of the first robot arm and the second robot arm, the corresponding bridge portion spanning between the corresponding first portion and the corresponding second portion of the second outer bypass section, and positioned such that the corresponding bridge portion of the second outer bypass section is farther from the first axis of the first robot arm of the second pair of the first robot arm and the second robot arm than the corresponding bridge portion of the second inner bypass section when the first robot arm of the second pair of the first robot arm and the second robot arm is in the first contracted state.

16. 16. The system of claim 15, wherein the first pair of the first robotic arm and the second robotic arm and the second pair of the first robotic arm and the second robotic arm are arranged symmetrically with respect to the reference plane.

17. 14. The system of claim 9 or any one of claims 11 to 13, wherein the first axes are spaced apart by a distance different from the spacing between the second axes.

18. 6. The system of claim 5, each of the first end effector support arms having a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion; the corresponding first portion and the corresponding second portion of each of the first end effector support arms extend along parallel axes, the parallel axes being offset from one another perpendicularly thereto; the corresponding offset jog portion of each of the first end effector support arms spans between the corresponding first portion and the corresponding second portion of the first end effector support arm.

19. 20. The system of claim 18, each of the second end effector support arms having a corresponding first portion, a corresponding second portion, and a corresponding offset jog portion; the corresponding first portion and the corresponding second portion of each of the second end effector support arms extend along parallel axes, the parallel axes being offset from one another perpendicularly thereto; the corresponding offset jog portion of each of the second end effector support arms spans between the corresponding first portion and the corresponding second portion of the second end effector support arm.

20. 17. The system of any one of claims 1 to 16, further comprising a transfer chamber, the base is fixedly attached to the transfer chamber; the fuselage unit is at least partially located within the transfer chamber; the first robot arm is located entirely within the transfer chamber when in the first retracted state; the second robot arm is located entirely within the transfer chamber when in the second retracted state; the fuselage unit, together with the first robotic arm and the second robotic arm, is rotatable within the transfer chamber by at least 90 degrees relative to the transfer chamber when the first robotic arm is in the first retracted state and the second robotic arm is in the second retracted state.

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