Substrate conveyance system and conveyance method

Abstract

This substrate conveyance system constitutes a semiconductor manufacturing apparatus for processing a substrate and is for conveying the substrate in a conveyance space, the system including: a substrate conveyance chamber constituting the conveyance space and including a plurality of electromagnets for forming a magnetic field with respect to a traveling surface; a moving body having a magnet for floating up from the traveling surface by the action of the magnetic field and configured to be movable along the traveling surface in a state of holding the substrate; and an auxiliary moving body having a magnet for floating up from the traveling surface by the action of the magnetic field and configured to be movable along the traveling surface while supporting the floating up of the moving body by coming into contact with the moving body when the moving body moves along the traveling surface while holding a conveyance object heavier than the substrate.

Description

Substrate Transfer System and Transfer Method

[0001] The present disclosure relates to a substrate transfer system and a transfer method.

[0002] For example, in a substrate processing apparatus that performs processing on a semiconductor wafer (hereinafter also referred to as "wafer") as a substrate, the wafer is transferred between a carrier that houses the wafer and a substrate processing chamber where the processing is executed. In transferring the wafer, substrate transfer mechanisms of various configurations are used. The applicant is proceeding with the development of a substrate transfer system that uses a moving body utilizing magnetic levitation to transfer substrates and components in a processing chamber.

[0003] As a transfer technique using a moving body capable of magnetic levitation, Patent Document 1 discloses two types of configurations: a transfer module including an arm portion having a fork-shaped substrate holding portion, and a transfer module including a stage on a main body that levitates magnetically and on which a wafer is placed and held. Among these, for the transfer module including a stage on the main body, a method of transferring a focus ring disposed in a wafer processing chamber by a plurality of transfer modules working together is described.

[0004] Japanese Unexamined Patent Application Publication No. 2022-113548

[0005] The present disclosure provides a technique in a semiconductor manufacturing apparatus in which a moving body configured to transfer a substrate while levitating magnetically transfers a transfer object heavier than a substrate such as a cover ring and suppresses an increase in the footprint.

[0006] The substrate transport system of this disclosure comprises a substrate transport system for transporting a substrate in a transport space, comprising: a substrate transport chamber comprising a plurality of electromagnets for forming a magnetic field with respect to a travel surface, which constitutes the transport space; a mobile body having a magnet for levitating from the travel surface by the action of the magnetic field and configured to move along the travel surface while holding the substrate; and an auxiliary mobile body having a magnet for levitating from the travel surface by the action of the magnetic field and configured to move along the travel surface while in contact with the mobile body when the mobile body is moving along the travel surface holding an object heavier than the substrate, thereby assisting the levitation of the mobile body.

[0007] According to this disclosure, in semiconductor manufacturing equipment, a mobile body configured to transport substrates by magnetic levitation can transport objects heavier than the substrate, such as coverings, while suppressing the expansion of the footprint.

[0008] This is a plan view showing a semiconductor manufacturing apparatus in an embodiment. This is a longitudinal side view illustrating a substrate processing module of the semiconductor manufacturing apparatus. This is a perspective view showing the interaction between the floor surface and the main body of the transport device. This is a longitudinal side view showing the tiles of the floor surface and the magnet unit of the main body. This is a side view showing the balance of forces when transporting a substrate with a transport device of a comparative form. This is a side view showing the balance of forces when transporting a covering with a transport device of a comparative form. This is a plan view showing the transport device and the first and second auxiliary devices of an embodiment. This is a side view showing the transport device and the first and second auxiliary devices of an embodiment. This is a first partial plan view showing the transport operation of a covering with an embodiment. This is a second partial plan view showing the transport operation of a covering with an embodiment. This is a third partial plan view showing the transport operation of a covering with an embodiment. This is a fourth partial plan view showing the transport operation of a covering with an embodiment. This is a fifth partial plan view showing the transport operation of a covering with an embodiment. This is a sixth partial plan view showing the transport operation of a covering with an embodiment. This is a seventh partial plan view showing the transport operation of a covering with an embodiment. This is an eighth partial plan view showing the transport operation of the covering of the embodiment. This is a ninth partial plan view showing the transport operation of the covering of the embodiment. This is a first side view showing a transport device and auxiliary device traveling on tiles with mounting errors. This is a second side view showing a transport device and auxiliary device traveling on tiles with mounting errors. This is a plan view showing the transport device and auxiliary device of a first modified example of the embodiment. This is a partial longitudinal front view showing the transport device and auxiliary device of a first modified example of the embodiment. This is a plan view showing the transport device and auxiliary device of a second modified example of the embodiment.

[0009] <Substrate Processing System> An example of a semiconductor manufacturing apparatus 100 that processes wafers according to this embodiment will be described below with reference to Figure 1. In this description, the XYZ coordinates shown in Figure 1 will be used as the main coordinate system. The semiconductor manufacturing apparatus 100 is configured to transport a substrate W, which is a wafer, to a processing module 11 by a substrate transport system 1 and to process it. Figure 1 shows a multi-chamber type semiconductor manufacturing apparatus 100 that includes a plurality of processing modules 11 for processing the substrate W and a stocker module 10 for storing and recovering the covering CR. As shown in Figure 1, the semiconductor manufacturing apparatus 100 includes an air transport module 12, a load lock module 13, a substrate transport module 14, and a plurality of processing modules 11 (or one stocker module 10), which are arranged in this order horizontally from the air transport module 12 side.

[0010] In this example, the semiconductor manufacturing apparatus 100 is configured such that the processing module 11 processes the substrate W under a vacuum atmosphere, and the substrate transport module 14 is under a vacuum atmosphere. In the following description of the semiconductor manufacturing apparatus 100 as a whole, the Y direction in Figure 1 is the front-to-back direction, and the X direction is the left-to-right direction. In the left-to-right direction, the tip of the arrow indicating the X direction is called the right, and the base end is called the left. In the front-to-back direction, the base end of the arrow indicating the Y direction is called the front (closer) side, and the tip of the Y direction is called the rear (back) side.

[0011] A load port 121 is provided on the front side of the atmospheric transport module 12. The load port 121 is configured as a platform on which carriers C containing substrates W to be processed are placed, and for example, four of them are installed side by side in the left-right direction. For the carrier C, for example, a FOUP (Front Opening Unified Pod) can be used. The atmospheric transport module 12 is in an atmospheric pressure (normal pressure) atmosphere, and for example, a downflow of clean air is formed. In addition, a transport mechanism 122, for example consisting of a multi-joint arm, is provided inside the atmospheric transport module 12, and is configured to transport the substrates W between the carrier C and the load lock module 13.

[0012] Between the atmospheric transport module 12 and the substrate transport module 14, for example, two load lock modules 13 are installed side by side. The load lock module 13 is configured to switch between an atmospheric pressure atmosphere and a vacuum atmosphere, and has a transfer stage 130 on which the substrate W is placed, and a lifting pin 131 that pushes up and holds the substrate W from below. For example, three lifting pins 131 are provided at equal intervals along the circumferential direction and are configured to move up and down. The lifting pins 112 provided in the processing module 11, which will be described later, are configured in a similar manner. The gaps between the load lock module 13 and the atmospheric transport module 12, and between the load lock module 13 and the substrate transport module 14, are configured to be openable and closable by gate valves G1 and G2, respectively.

[0013] As shown in Figure 1, the substrate transport module 14 includes a rectangular chamber (substrate transport chamber) 140 that is long in the front-to-back direction and has a plan view. The chamber 140 constitutes a transport space 140n for transporting substrates W and includes a floor portion 141 on which a coil 3 (described later) is provided, and side wall portions 142 that surround this floor portion 141. In this example, the transport space 140n inside the chamber 140 is reduced to a vacuum atmosphere by a vacuum evacuation mechanism (not shown). Either a processing module 11 or a stocker module 10 is connected to the left and right side wall portions 142, from front to rear.

[0014] Specifically, on the left side wall 142, two processing modules 11, a stocker module 10, and another processing module 11 are arranged in this order from front to back. The processing module 11 furthest in the back is the processing module 11r used in the explanation of the transport operation example described later. On the right side wall 142, four processing modules 11 are arranged. Each processing module 11 on the side wall 142 has an opening 110 for transporting substrates W to that processing module 11, and each opening 110 is configured to be openable and closable by a gate valve G3. Substrates W are loaded and unloaded between the substrate transport module 14 and the processing modules 11 through these openings 110.

[0015] Each processing module 11 is depressurized to a vacuum atmosphere by a vacuum evacuation mechanism (not shown). Inside each processing module 11, there is a mounting table 111 for positioning the substrate W and covering CR in predetermined locations. The substrate W is placed on the mounting table 111 with the covering CR already placed on it, and processing gas is supplied to perform the predetermined processing. Figure 2 is a longitudinal cross-sectional side view illustrating these processing modules. The stocker module 10, like the load lock module 13, is configured to switch between an atmospheric and a vacuum atmosphere, and is set to be in a vacuum atmosphere when the covering CR is transported in and out of the processing module 11 via the substrate transport module 14, as will be described later.

[0016] <Substrate Processing Module> An example of a configuration in which the processing module 11 is configured to perform processes such as etching, cleaning, and ashing on a substrate W is shown. The substrate transport module 14 shown in Figure 2 includes a processing container (processing chamber) 41, a gas supply unit 42, an RF power supply unit 43, an exhaust mechanism 44, and a lifter 45. The processing container 41 is connected to the side wall portion 142 as shown in Figure 1, forming a processing space. The substrate mounting table 111 described above is placed within this processing space. By placing the substrate W on the mounting table 111, which has a covering CR on its periphery, the substrate W is positioned at a preset position in the processing space. The substrate mounting table 111 includes a base 46 placed at the bottom of the processing container 41, an electrostatic chuck 47 attached to the base 46, a lower electrode 48, and a temperature adjustment mechanism 49 for adjusting the temperature of the placed substrate W and covering CR.

[0017] The electrostatic chuck 47 is positioned on the lower electrode 48, and the upper surface of the electrostatic chuck 47 constitutes a substrate support surface 51 and a ring support surface 52 (Figures 1 and 2). The electrostatic chuck 47 supports the substrate W with the substrate support surface 51 and supports the covering ring CR with the ring support surface 52. The electrostatic chuck 47 is made of an insulating material and has a first adsorption electrode and a second adsorption electrode (not shown) embedded in it. The first adsorption electrode is located below the substrate support surface 51. The electrostatic chuck 47 adsorbs and holds the substrate W on the substrate support surface 51 by applying a voltage to the first adsorption electrode. The second adsorption electrode is located below the ring support surface 52. The electrostatic chuck 47 adsorbs and holds the covering ring CR on the ring support surface 52 by applying a voltage to the second adsorption electrode.

[0018] The covering CR is configured in an annular shape and is positioned around the substrate W on the periphery of the lower electrode 48. The covering CR has an inclined inner surface for guiding the substrate W, and its radial width increases from top to bottom. The covering CR protects the upper surface of the base 46 from plasma generated in the processing space and improves the uniformity of the plasma treatment on the substrate W.

[0019] The covering CR is formed from a conductive material such as silicon (Si) or silicon carbide (SiC). Alternatively, the covering CR may be formed from an insulating material such as quartz. When a predetermined number of substrates W have been processed, the covering CR is replaced with a new, clean covering CR stocked in the stocker module 10. The base 46 is provided to surround and support the covering CR, the electrostatic chuck 47, and the lower electrode 48.

[0020] The temperature control mechanism 49 controls the temperature of the substrate W and the covering CR as a whole. The temperature control mechanism 49 is provided inside the electrostatic chuck 47. The temperature control mechanism 49 can be fitted with, for example, a heater, a structure that circulates a heat exchange medium from a heat exchange medium circulation unit (not shown), or a structure that supplies heat transfer gas from a gas supply and exhaust unit (not shown).

[0021] A shower head 55 is attached to the upper opening of the processing container 41 via an insulating member. The shower head 55 is configured to supply one or more processing gases from the gas supply unit 42 to the processing space. The shower head 55 is positioned opposite the lower electrode 48 and constitutes the upper electrode to which RF power is supplied by the RF power supply unit 43. The shower head 55 also includes a gas diffusion space 56, and the bottom surface of the shower head 55 is provided with a plurality of gas discharge holes 57 that communicate with the gas diffusion space 56 and the processing space. The top surface of the shower head 55 is provided with a gas supply hole to which the gas supply unit 42 is connected. Through this gas supply hole, one or more processing gases are supplied from the gas supply unit 42 to the processing space, passing through the gas diffusion space 56 and the gas discharge holes 57.

[0022] An opening 110, which serves as an inlet / outlet and is opened and closed by a gate valve G3, is provided in the side wall of the processing container 41. The substrate W is transported in and out of the processing container 41 to the substrate transport module 14 outside the processing container 41 through the inlet / outlet (opening) 110.

[0023] The gas supply unit 42 includes one or more gas supply units and flow controllers (not shown). The gas supply unit 42 supplies one or more types of processing gas from each gas supply unit to the gas supply port via each flow controller. The flow controllers include, for example, a mass flow controller for adjusting the gas flow rate and a valve for supplying and cutting off the gas. The RF power supply unit 43 includes an RF power supply 58 and a matching unit 59. The RF power supply 58 supplies RF power to the shower head 55, which is the upper electrode, via the matching unit 59.

[0024] The exhaust mechanism 44 is connected to a gas exhaust port, for example, located at the bottom of the processing container 41. The exhaust mechanism 44 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the processing space. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0025] The lifter 45 includes a substrate lifter 61 for raising and lowering the substrate W, and a ring lifter 62 for raising and lowering the covering CR. The ring lifter 62 and the substrate lifter 61 each include a lifting pin 66, the aforementioned lifting pin 112, and a lifting mechanism 67 and a lifting mechanism 65, respectively. Three lifting pins 66 and three lifting pins 112 are provided, and they are inserted through holes formed in the lower electrode 48 and the electrostatic chuck 47, so that they can protrude and retract on the ring support surface 52 and the substrate support surface 51 of the electrostatic chuck 47. The lifting pins 66 and 112 protrude from the upper surface of the electrostatic chuck 47, so that their upper ends contact the lower surfaces of the covering CR and the substrate W, respectively, to support the covering CR and the substrate W.

[0026] The lifting mechanisms 67 and 65 raise and lower multiple lifting pins 66 and 112. For the lifting mechanisms 67 and 65, for example, motors such as DC motors, stepping motors, and linear motors, air-driven mechanisms such as air cylinders, and piezo actuators can be used. The ring lifter 62 and substrate lifter 61 raise and lower multiple lifting pins 66 and 112 when transferring covering CR and substrate W between the substrate mounting table 111 and the transport device 2 described later.

[0027] <Stocker Module 10> Although not shown in the figures, the stocker module 10 includes, for example, a storage section for storing multiple clean coverings CR, and a recovery section for recovering coverings CR that have been used and replaced in the processing module 11. The stocker module 10 is also provided with a mounting table 10a and support pins 10b having a structure similar to that of the lifting pins 66. The clean coverings CR in the storage section are placed on the mounting table 10a by a transfer mechanism (not shown) and are transferred by the support pins 10b to the transport device 2, which will be described later and is provided on the substrate transport module 14.

[0028] <Overview of the transport device 2, first and second auxiliary devices 81 and 82> The substrate transport module 14 is equipped with a plurality of transport devices (moving bodies) 2 for transporting substrates W and covering CR, and auxiliary devices (auxiliary moving bodies) 81 and 82 for assisting the transport of the transport devices 2 when transporting covering CR. As shown in Figures 1 and 3, the transport device 2 has a main body 21 that is placed on the floor surface 141 of the chamber 140. The upper surface of the floor surface 141 is the travel surface of the transport device 2. The main body 21 is provided with transport arms 22 that horizontally hold the substrates W and covering CR to be transported. The transport arms 22 are provided so as to extend in a direction along the floor surface 141 (horizontal direction) when the main body 21 is placed on the floor surface 141.

[0029] For example, the tip of the transport arm 22 is configured as a fork 23 that can surround from the left and right sides the area where the three lifting pins 131 and 112 for supporting the substrate W are provided, when inserted into the load lock module 13 and the processing module 11 (Figure 1). The fork 23, arranged in this manner, is positioned inside the area where the three lifting pins 66 for supporting the covering CR are provided, for example, so as not to come into contact with them. The transport arm 22 is configured to be long enough to transfer the substrate W to the mounting table 111 by, for example, opening the gate valve G3 while the main body 21 is positioned inside the chamber 140 and inserting it into the processing module 11 through the opening 110.

[0030] <Chamber 140 of the substrate transport module 14> Returning to Figure 1 and continuing the explanation, the length of the shorter side of the rectangular chamber 140 in plan view is such that two transport devices 2, each holding a substrate W, can pass each other side by side. The length of the shorter side of the chamber 140 is such that the first and second auxiliary devices 81 and 82 can assist the transport device 2, in which the forks 23 are placed inside the processing module 11 or stocker module 10 (Figure 9D). Specifically, this length is such that the transport device 2, in which the transport arms 22 other than the forks 23 are placed inside the chamber 140, and the second auxiliary device 82 connected to the transport device 2 can be placed side by side along the shorter side (Figure 9C). The length of the longer side of the chamber 140 is such that a substrate can be transported to the innermost processing module 11, and that the standby areas for the first and second auxiliary devices 81 and 82 can be placed even further back than the processing module 11 (Figures 9F and 9G). The standby section is provided so as not to interfere with the movement path of the transport device 2 (exemplified in Figures 9A to 9I), which will be described later.

[0031] In this example, substrates W and covering CR are transported using multiple transport devices 2 and first and second auxiliary devices 81 and 82 installed inside the chamber 140. The transport devices 2 and the first and second auxiliary devices 81 and 82 are configured to move on the floor surface 141 using magnetic levitation, but the configuration of the magnetic levitation mechanism will be described later.

[0032] <Transport and Processing Operations for Substrate W> An example of the transport and processing operations for substrate W in the semiconductor manufacturing apparatus 100 having the above configuration will be described. First, a carrier C containing the substrate W to be processed is placed on the load port 121. Then, the transport mechanism 122 in the atmospheric transport module 12 removes the substrate W from the carrier C and loads it into the load lock module 13, and in cooperation with the lifting pin 131, the substrate W is transferred to the stage 130. Then the transport mechanism 122 is retracted from the load lock module 13, the gate valve G1 is closed, and the atmosphere inside the load lock module 13 is switched from an atmospheric pressure atmosphere to a vacuum atmosphere.

[0033] When the load lock module 13 is in a vacuum, the gate valve G2 is opened. At this time, inside the substrate transport module 14, the transport device 2 is waiting in a position facing the load lock module 13 near the connection point of the load lock module 13, and the transport device 2 is raised by magnetic levitation. Next, the transport device 2 is moved forward so that the transport arm 22 enters the load lock module 13, and the substrate W is received from the stage 130 to the fork 23 of the transport arm 22 via the lifting pin 131. Moving the transport device 2 forward means moving the main body 21, which moves under the repulsive force as described later, toward the fork 23, and moving the transport device 2 backward is movement in the opposite direction of this forward movement.

[0034] Next, the transport device 2 holding the substrate W is moved backward, causing the transport arm 22 to exit the load lock module 13, and the transport device 2 is moved backward to a position to the side of one of the processing modules 11 that will process the substrate W. At this time, the main body 21 of the transport device 2 moves past the position of the gate valve G3 of the processing module 11 and to the far side. This operation positions the tip of the transport arm 22 holding the substrate W approximately to the side of the gate valve G3.

[0035] Next, the gate valve G3 is opened, and the transport device 2 is advanced while rotating the tip of the transport arm 22 so that it faces the gate valve G3, inserting the substrate W into the processing module 11. After that, as shown in Figure 1 when the transport device 2 has entered the processing module 11r, it is facing the processing module 11, stops rotating, and moves straight until the substrate W reaches above the mounting table 111. Then, the substrate W is transferred to the mounting table 111 via the lifting pin 112, and the transport device 2 is moved away from the processing module 11. After closing the gate valve G3, processing of the substrate W is started.

[0036] In the processing module 11, the exhaust mechanism 44 creates a vacuum atmosphere within the processing space, and if necessary, the substrate W placed on the mounting table 111 is heated to a preset temperature, while the gas supply unit 42 supplies processing gas into the processing module 11. In this way, the desired processing of the substrate W is performed. Once the processing of the substrate W is complete, the substrate W is transported in the reverse order of its arrival and returned from the processing module 11 to the load lock module 13. Furthermore, after switching the atmosphere in the load lock module 13 to an atmospheric pressure atmosphere, the transport mechanism 122 on the atmospheric transport module 12 side removes the substrate W from the load lock module 13 and returns it to the predetermined carrier C.

[0037] Thus, in the semiconductor manufacturing apparatus 100, the substrate W is transported to at least one of the processing modules 11 for processing, and the transport of the substrate W is performed by the substrate transport system 1. The substrate transport system 1 in this example comprises a floor section 141 on which a large number of coils (electromagnets) 3 are provided, a transport device 2, and a control unit 5. The transport device 2 is configured to move using magnetic levitation based on the repulsive force between it and the coils 3.

[0038] <Control Unit> Furthermore, the semiconductor manufacturing apparatus 100 is equipped with a control unit 5. The control unit 5 is composed of a computer equipped with a CPU and a memory unit, and controls each part of the semiconductor manufacturing apparatus 100. The memory unit stores a program that consists of a set of steps (instructions) for controlling the operation of the processing module 11, etc. This program is stored in a storage medium such as a hard disk, compact disk, magnetic optical disk, memory card, or non-volatile memory, and is installed from there into the computer.

[0039] In addition, the storage unit stores a program for performing the conveyance operation of the substrate W and the like by the conveyance device 2 and the auxiliary operations of the first and second auxiliary devices 81 and 82. Based on this program, as will be described later, the control unit 5 moves the conveyance device 2 along the movement path, transfers the substrate W and the cover ring CR, and controls the repulsive force of each magnet so that a certain levitation force as described later acts on the first and second auxiliary devices 81 and 82. In the substrate conveyance module 14 of this example, on the floor surface portion 141 provided with a large number of coils 3, the conveyance device 2 provided with magnets and the first and second auxiliary devices 81 and 82 are magnetically levitated using the repulsive force with the coils 3 and move along the upper surface of the floor surface portion 141.

[0040] <Coil 3> First, the coil 3 provided on the floor surface portion 141 will be described with reference to FIGS. 3 and 4. A large number of coils 3 are linearly provided on the floor surface portion 141 of the substrate conveyance module 14. Specifically, the floor surface portion​​​​​A number of X coils 31 are arranged on the floor surface portion 141 at intervals in the Y direction, and each X coil 31 is composed of a coil wire 310. A number of Y coils 32 are arranged on the floor surface portion 141 at intervals in the X direction, and each Y coil 32 is composed of a coil wire 320. As shown in FIG. 4, a plurality of coil wires 310 and 320 constituting these X coils 31 and Y coils 32 are arranged in an alternating laminated manner. In FIG. 4, an example in which three layers of coil wires 310 are laminated to form each X coil 31 and three layers of coil wires 320 are laminated to form each Y coil 32 is schematically shown. These coil wires 310 and 320 laminated vertically are insulated from each other by an insulating layer 33.

[0043] As shown in FIG. 4, the coil wire 310 laminated in three layers to form the X coil 31 is electrically connected to one end side or the other end side of the coil wire 310 arranged on the upper layer side or the lower layer side at one end side or the other end side in the X direction thereof. Thus, when looking at the X-Z longitudinal section, the laminated coil wires 310 are connected in a spiral shape, for example, and both ends thereof are connected to the power supply circuit 34 respectively, thereby constituting the coil 31.

[0044] Similarly, the coil wire 320 laminated in three layers to form the Y coil 32 is electrically connected to one end side or the other end side of the coil wire 320 arranged on the upper layer side or the lower layer side at one end side or the other end side in the Y direction thereof. Although not shown, when looking at the Y-Z longitudinal section, the laminated coil wires 320 are connected in a spiral shape, for example, and both ends thereof are connected to a power supply circuit (not shown) respectively.

[0045] The configurations of the X coil 31 and the Y coil 32 illustrated above are not limited thereto. As long as a predetermined magnetic force can be applied to the magnet units 24, 25, 26, 27 on the conveyance device 2 side along the X direction and the Y direction set in the substrate conveyance module 14, other configurations may be used. Also, in each tile 143, a hall sensor layer (hall elements) (not shown) in which a number of hall sensors for specifying the position of the conveyance device 2 are arranged at intervals and in alignment is arranged above the coil 3 formed by such lamination.

[0046] The power supply circuit 34, which supplies power to the Y coil 32, supplies DC power to the selected X coil 31 and Y coil 32 based on a command from the control unit 5. A magnetic field is formed on the upper surface of the floor portion 141 in the area where the powered X coil 31 and Y coil 32 are located. The selection of the X coil 31 and Y coil 32 to which power is supplied, as well as the direction and magnitude of the current flow, can be adjusted according to the posture, levitation amount, direction and speed of movement of the transport device 2.

[0047] Next, the transport device 2 and the first and second auxiliary devices 81 and 82 will be described. The transport device 2 and the first and second auxiliary devices 81 and 82 are equipped with multiple magnet units in the main body 21 and the main body 83 and 84 described later, for generating a repulsive force against the magnetic field formed on the floor surface 141 by the above configuration. In the following description, the Y' direction, which is set in correspondence with the direction in which the transport arm 22 extends from the main body 21 of the transport device 2, and the X' direction, which is perpendicular to the Y' direction, are set in a common horizontal plane, and the direction moving upward from this horizontal plane is set as the Z' direction (Figures 3 and 4). The directions along these X'-Y'-Z' are also called the "sub-coordinate directions". The X-Y-Z directions described above, which are set on the transport module 14 side, are also called the "main coordinate directions".

[0048] <Conveying device 2> Figure 4 is a longitudinal cross-sectional side view of the magnet unit 24 as seen along the X'-Z' plane shown in Figure 3, and shows the internal structure of the magnet unit 24 and the tile 143. As shown in Figures 3(a) and (b), the main body 21 of the conveying device 2 is configured, for example, in a square shape in plan view, and the bottom surface of the main body 21 faces the floor surface 141. In Figure 3, the main body 21 is shown positioned on the floor surface 141 such that the four sides constituting the periphery of the main body 21 are parallel to the X and Y directions of the main coordinates. Furthermore, in these figures, the Y' direction of the secondary coordinates to which the conveying arm 22 extends (the conveying arm 22 is not shown in Figure 3) is positioned along the Y direction of the main coordinates.

[0049] <Magnetic Units> As illustrated in Figure 3, each of the magnetic units 24, 25, 26, and 27 is a plate-like body composed of a rectangle in plan view with the same shape as the others, and is made up of multiple magnets, as will be described in detail later. Each of these magnetic units 24 to 27 extends horizontally, with each long side positioned along the four sides of the outer edge of the main body 21. In adjacent magnetic units 24 to 27, the longitudinal end of the other magnetic unit 26, 25, 27, and 24 is located on the longitudinal extension of one magnetic unit 24, 26, 25, and 27. With this arrangement, the four magnetic units 24 to 27 are configured to form an annular body and are arranged to be rotationally symmetric about the Z' axis.

[0050] In Figure 3, the two magnet units 24 and 25 are arranged with their long sides aligned along the Y' direction, and the magnet units 26 and 27 are arranged with their long sides aligned along the X' direction. Figure 4 shows a representative example of these magnet units 24. For example, each magnet unit 24 and 25 is composed of nine permanent magnets 28. The nine permanent magnets 28 are formed in an elongated prismatic shape extending along the Y' direction, and these permanent magnets 28 are arranged along the X' direction.

[0051] Figure 4 schematically shows the orientation of the north poles of each permanent magnet 28 constituting the magnet unit 24 using arrows. As shown in the figure, each permanent magnet 28 is positioned so that its north pole faces either the Z' or X' direction, and the orientation of the north poles of adjacent permanent magnets 28 is periodically changed by 90°. The nine permanent magnets 28 arranged in this manner form a Halbach arrangement, creating a stronger magnetic field below than above, resulting in a configuration that provides a high levitation force.

[0052] The remaining magnet units 26 and 27 have the same configuration as the magnet units 24 and 25 described above, except that their length is aligned with the X' direction. Therefore, the configuration of magnet units 26 and 27 can be described by reinterpreting the description of the configuration of magnet units 24 and 25 as if they were rotated 90° around the Z axis.

[0053] Next, the operation of the magnet units 24 and 25 will be explained with reference to Figure 3(a). Figure 3(a) shows the state in which power is supplied to the Y coils 32 corresponding to the magnet units 24 and 25. The Y coils 32 to which power is supplied are shown with thick lines, and the Y coils 32 to which power is not supplied are shown with thin lines. The arrows added to the Y coils 32 shown with thick lines indicate the direction of current flow through each Y coil 32. Figure 3(a) shows an example in which the direction of current flow supplied to the selected Y coils 32 is the same. However, in reality, the direction and magnitude of current flow in each selected Y coil 32 may differ from one another.

[0054] The magnet unit 24 forms a magnetic field in a rectangular region having a long side extending along the Y direction, and a repulsive force acts between it and the magnetic field formed by supplying power to the selected Y coil 32. Thus, as shown in Figure 3(a), the magnet unit 24 experiences a force F in the Z direction due to the repulsive force with the magnetic field formed on the selected Y coil 32. ｚ４ and force F in the X direction Ｘ４ This occurs. As a result, the magnetic unit 24, due to the repulsive force between itself and the magnetic field of the Y coil 32, causes the portion of the main body 21 on which the magnetic unit 24 is installed to levitate, and also moves the main body 21 in the positive direction of X.

[0055] As explained above using magnet unit 24 as an example, a similar repulsive force acts between magnet units 25 to 27 and the magnetic field generated by the supply of power to the corresponding coils 31 and 32, resulting in the forces illustrated in Figures 3(a) and 3(b). In short, magnet unit 25 experiences a force F in the Z direction due to the repulsive force with the magnetic field formed by the current flowing through the selected Y coil 32. ｚ５ and force F in the X direction Ｘ５ This occurs (Figure 3(a)). As a result, the repulsive force between the magnet unit 25 and the Y coil 32 causes the portion of the main body 21 on which the magnet unit 24 is provided to levitate, and also moves the main body 21 in the positive direction of X.

[0056] The magnet unit 26 exerts a force F in the Z direction due to the repulsive force with the magnetic field formed by the current flowing through the selected X coil 31. ｚ６and force F in the Y direction Ｙ６ This occurs (Figure 3(b)). As a result, the magnet unit 26, due to the repulsive force between itself and the X coil 31, levitates the portion of the main body 21 on which the magnet unit 26 is installed, and moves the main body 21 in the positive Y direction. The magnet unit 27 is subjected to a force F in the Z direction due to the repulsive force with the magnetic field formed by the current flowing through the selected X coil 31. ｚ７ and force F in the Y direction Ｙ７ This occurs (Figure 3(b)). As a result, the repulsive force between the magnet unit 27 and the X coil 31 causes the portion of the main body 21 on which the magnet unit 27 is installed to levitate, and also moves the main body 21 in the positive direction of Y.

[0057] In the movement of the transport device 2 due to the repulsive force described above, the control unit 5 controls the repulsive force necessary to operate the transport device 2 by adjusting the selection of the coils to be supplied with power from among the many coils 3 and the magnitude of the power supplied to the selected X coil 31 and Y coil 32. Furthermore, when DC power is supplied to the X coil 31 and Y coil 32 from a power supply circuit such as the power supply circuit 34, the direction of movement of the transport device 2 can be controlled by setting the direction of current flow to each coil 31 and 32.

[0058] In this way, the position, magnitude, and direction of the magnetic field are adjusted in the X coil 31 and Y coil 32. By controlling this magnetic field, the levitation force of the main body 21, the amount of levitation (levitation distance) from the floor surface 141, and the orientation and direction of movement of the main body 21 are adjusted. As a result, the main body 21 can be made to assume a desired posture on the floor surface 141 and to move in a desired direction. In the above explanation, the case in which the main body 21 moves forward and to the left was used as an example, but by adjusting the power supply to the coil 3, the main body 21 can also move backward and in the negative X direction. In addition to these translational movements, rotational movements such as rotating the main body 21 90° around the Z' axis and stopping the main body 21 in a levitating state are also possible.

[0059] The configuration of the main body 21 of the transport device 2 and the operation of the magnets are the same for the main bodies 83 and 84 of the first and second auxiliary devices 81 and 82 as described above. However, the area occupied by the main bodies 83 and 84, where the magnets are provided (described later), is smaller than the area occupied by the main body 21. Furthermore, the width of each magnet unit in the main bodies 83 and 84 is smaller than the width of each magnet unit 24 to 27 in the main body 21. As a result, the area over which the main bodies 83 and 84 receive repulsive force from the magnetic field is smaller, and is smaller than the repulsive force of the main body 21. However, for example, the total mass of the magnet units provided in the main bodies 83 and 84 is lighter than the total mass of the magnet units 24 to 27 of the transport device 2, and since they do not hold the transport arm 22 or the covering CR, the first and second auxiliary devices 81 and 82 are lighter overall. Such first and second auxiliary devices 81 and 82 provide the transport device 2 with sufficient levitation force and can perform the auxiliary operations described later. Furthermore, because the main body sections 83 and 84 occupy a relatively small area, the area they occupy in standby mode on the limited floor surface 141 is reduced, making it less likely to interfere with the transport operation of the transport device 2's substrate W and covering CR. In addition, when the transport device 2 is performing auxiliary operations, it can move easily without interfering with the transport operation of other transport devices 2 on the floor surface 141 that are not providing assistance.

[0060] Here, we will describe a comparative configuration in which the transport device 2m transports the substrate W and covering CR independently, without using the auxiliary devices 81 and 82, compared to the transport operation using the transport device 2 and the first and second auxiliary devices 81 and 82 of the embodiment described later. Figures 5 and 6 are side views showing the balance of forces acting in the Z direction when the transport device 2m transports the substrate W and covering CR by magnetic levitation on its own.

[0061] The transport device 2m in the comparative configuration shown in Figures 5 and 6 and the transport device 2 in the embodiment shown in Figure 8, etc., are configured in substantially the same way. However, in terms of arranging the first and second auxiliary devices 81 and 82 described later, the transport device 2 in the embodiment may have a greater height dimension (thickness) in the height direction of the main body 21 than the transport device 2m in the comparative configuration. For the transport device 2m, the main body 21 is made up of a rectangular plate-like body with a relatively thin thickness, and a transport arm 22 is provided so as to extend horizontally from the center of the periphery along one side (Figures 1 and 5). When the transport device 2m that transports the substrate W levitates, if the combined gravity G of the transport device 2 and the substrate W acts at the center of gravity, then it is necessary to apply thrusts F6 and F7 in the Z direction to the magnet units 26 and 27 provided at the front (front side of the Y' axis) and rear (rear end side of the Y' axis), respectively, of the main body 21. Furthermore, these thrusts F6 and F7 act at the center of gravity of each magnet unit 26 and 27, and when the direction of their action is upward, they are sometimes referred to as levitation forces F6 and F7, and when the direction of their action is downward, they are sometimes referred to as attractive forces F6 and F7.

[0062] For example, when a substrate W weighing 130g is held by the fork 23, the center of gravity G of the entire transport device 2m and substrate W is located closer to the fork 23 than to the center of the main body 21, as shown in Figure 5. In this case, the gravity G and the thrusts F6 and F7 must be balanced, so the thrusts F6 and F7 are both made to act upward. Furthermore, considering the rotational moment applied to the main body 21 from the fork 23 side holding the substrate W, in order to maintain the horizontal posture of the transport device 2m, the levitation force F6 of the front magnet unit 26 must be greater than the levitation force F7 of the rear magnet unit 27.

[0063] In contrast, when a covering CR weighing 1 kg, which is heavier than the substrate W, is held by the fork 23, the center of gravity G of the entire transport device 2m and covering CR shifts significantly towards the fork 23, as shown in Figure 6, and becomes located in front of the main body 21. In this case, considering the rotational moment applied to the main body 21 from the fork 23 side holding the covering CR, in order to maintain the horizontal posture of the transport device 2m, it is necessary to further increase the levitation force F6 of the magnet unit 26 at the front end, while applying an attractive force F7 to the magnet unit 27 at the rear end, pulling it towards the floor surface 141.

[0064] In order to cancel the large rotational moment applied from the covering CR using only the thrust of the magnet units 26 and 27, which are relatively close to each other, calculations show that a levitation force F6 of about twice the amount required to hold the substrate W is necessary. To apply such a large levitation force F6, it is necessary to supply even more power to the X coil 3 or to increase the width dimension of the magnet units 26 and 27 (the width dimension in the X' direction shown in Figure 3(b)). If the width dimension of the magnet units 26 and 27 is increased, the magnet units 24 and 25 must also have the same width dimension, so as mentioned above, the area of ​​the region where the magnet units 24 to 27 are provided increases, and the area of ​​the main body 21 itself also increases. Furthermore, in order to move multiple transport devices 2m equipped with such large main body 21s, the floor surface 141 of the chamber 140 must also be widened, resulting in the problem of increased footprint for the substrate transport system 1 and semiconductor manufacturing equipment 100.

[0065] Therefore, in the embodiments described below, when transporting objects heavier than the substrate W, such as covering CR, two types of auxiliary devices (first and second auxiliary devices 81 and 82) are used to assist in the levitation of the main body 21 of the transport device 2.

[0066] Figures 7 and 8 are plan and side views, respectively, of the transport device 2 and the first and second auxiliary devices 81 and 82 of the embodiment. In Figure 8, the levitation forces F6 and F7 acting on the magnet units 26 and 27 are indicated by arrows, but the length of the arrows does not represent the magnitude of the force, but merely indicates the direction in which the force acts. The following description of the transport device 2 will focus on the differences from the comparative transport device 2m.

[0067] First, let's explain the assistance for levitation using the first auxiliary device 81. The conveying device 2 is configured such that the levitation of the covering CR during conveying is assisted when the conveying arm 22, which is holding the covering CR, is pushed up from below while in contact with the levitated first auxiliary device 81. Specifically, the first auxiliary device 81 is inserted below the conveying arm 22 from the side of the conveying arm 22, that is, from a direction intersecting the extension direction of the conveying arm 22, and the first auxiliary device 81 is configured to push up the conveying arm 22 in order to apply a certain levitation force to the conveying arm 22.

[0068] Therefore, the height at which the transport arm 22 is positioned is such that the first auxiliary device 81, which floats below it, can be positioned. Specifically, the height at which the transport arm 22 is positioned relative to the lower surface of the main body 21 is set to be the same as or greater than the total length of the first auxiliary device 81 in the Z direction. In order to position the transport arm 22 at such a height, the height dimension of the main body 21 on the transport device 2 side is set to be greater than the height dimension of the main body 83 of the first auxiliary device 81. The main body 21 of the transport device 2 does not need to be a roughly rectangular parallelepiped shape with such a height; it may be formed to be higher by making the upper surface portion of the main body 84, to which the connecting portion 86 is provided, protrude, as in the second auxiliary device 82 (Figure 8).

[0069] Next, assistance for levitation using the second auxiliary device 82 will be described. The main body 21 of the transport device 2 is arranged adjacent to the main body 21 and is configured to be connected to the second auxiliary device 82 in a levitated state. With this configuration, the main body 21 and the second auxiliary device 82 are integrated in contact, and the levitation of the main body 21 is assisted by the second auxiliary device 82. Specifically, the connecting portion 86 on the second auxiliary device 82 side can be connected to the central position on the rear end side of the upper surface of the main body 21, opposite to the connection position of the transport arm 22. A detachable member 86m is provided on the lower surface of the connecting portion 86 to detachably attach to the upper surface of the main body 21. The detachable member 86m is configured as a magnet holder in which, for example, two permanent magnets are built in, and the direction of the magnetic flux of the permanent magnets is switched by instantaneous power supply as described later, forming magnetic fields with different directions below the detachable member 86m, and switching between an attracted state (on) and a detached state (off). The main body 21 and the second auxiliary device 82 can be connected and separated by switching the attachment / detachment member 86m on and off. In order to attach and detach the connecting part 86 using the attachment / detachment member 86m, the upper surface of the main body 21 is made of a magnetic material. The attachment / detachment member 86m may also be composed of an electromagnet whose attractive state is maintained by maintaining a power supply state. The total length of the main body 84 of the second auxiliary device 82 in the Z' direction is set to be the same as or greater than the height dimension from the lower surface of the main body 21 to the upper surface of the transport arm 22.

[0070] The first and second auxiliary devices 81 and 82 each comprise the main body portions 83 and 84 described above, and a pressing portion 85 or a connecting portion 86 provided on the main body portions 83 and 84. At the bottom of the main body portions 83 and 84 are four magnet units (not shown) described above, which are used to obtain a repulsive force from the magnetic field formed by the coil 3. In order to connect to the upper surface of the main body portion 21 which has been lifted by the lift amount H described later during transport, the height of the lower surface of the connecting portion 86 of the second auxiliary device 82 which has been lifted by the lift amount H2 is set to be the same as the upper surface of the main body portion 21, as shown in Figure 8. In order to position the connecting portion 86 at this height, the upper surface portion of the main body portion 84 on which the connecting portion 86 is provided is provided to protrude upward so as to be higher than the other upper surface portions.

[0071] In the first auxiliary device 81, the pressing portion 85 is made of, for example, aluminum, and a cover 85a is provided on its upper surface. The cover 85a is made of a vacuum-compatible resin that reduces outgassing in a vacuum atmosphere, and suppresses the generation of particles due to contact with the transport arm 22 and slight sliding. The cover 85a is subjected to a constant upward bias by the first auxiliary device 81 and a downward bias by the transport arm 22. As a result, static friction force is generated between the cover 85a and the transport arm 22, and the cover 85a can move in accordance with the transport arm 22 as it moves during the transport of the covering CR. The cover 85a may also be an O-ring attached to the upper peripheral edge of the pressing portion 85.

[0072] Furthermore, in the second auxiliary device 82, the connecting portion 86 is provided with the aforementioned attachment / detachment member 86m located at its tip, and a power supply circuit (not shown) configured to supply power to it as needed. The power supply circuit may be provided in a location other than the connecting portion 86, for example, in the main body portion 84. The powered attachment / detachment member 86m allows the lower surface of the tip of the connecting portion 86 to be connected to and separated from the aforementioned position on the main body portion 21. In this way, since the flat lower surface of the connecting portion 86 is connected to and separated from the upper surface of the main body portion 21 by magnetic force, particle generation is suppressed.

[0073] The transport device 2, which supports the covering CR and is connected to the second auxiliary device 82, experiences an increase in the gravitational force G acting on it due to the mass of the second auxiliary device 82. However, the center of gravity is displaced towards the main body 84 compared to the center of gravity position shown in the comparative configuration (Figure 6). Therefore, in the comparative configuration shown in Figure 6, the significant bias in the levitation force F6 on the tip-side magnet unit 26 can be reduced.

[0074] Regarding the first and second auxiliary devices 81 and 82 as described above, the control unit 5 controls the power supply to each coil 3 located below the main body 83 and 84 so that the vertical repulsive force to the main body 83 and 84 remains constant. In the comparative configuration shown in Figure 6, the thrust (levitation force F6, attractive force F7) of the magnet units 26 and 27, which are arranged in close proximity to each other within the main body 21 of the transport device 2m, must offset the moment received from the covering CR side. In contrast, the first auxiliary device 81 can reduce the rotational moment applied to the main body 21 by pushing up the transport arm 22 as described above. On the other hand, since the second auxiliary device 82 is connected to the main body 21 via the connecting part 86, the main body 21 and the second auxiliary device 82 (main body 84) can be considered as one unit. In this case, the moment received from the covering CR side is offset by four magnet units (magnet units 26 and 27 on the conveying device 2 side and two magnet units not shown on the second auxiliary device 82 side) that are distributed from the tip of the main body 21 of the conveying device 2 to the rear end of the main body 84 of the second auxiliary device 82. As a result, compared to the case where a large moment is offset by only the magnet unit 26 on the tip side of the main body 21, as in the conveying device 2m of the comparative form, it is possible to reduce the maximum output required for each magnet unit, and the covering CR can be included without increasing the area of ​​the magnet units themselves.

[0075] Various methods can be considered for controlling the transport of the covering CR when it is assisted by the first and second auxiliary devices 81 and 82. As a first method, the main body 21 of the transport device 2 is controlled to supply power to the coil 3 so that it moves at a height of levitation amount H during transport, as described using the conventional method explained with reference to Figures 3(a) and (b). In contrast, the first auxiliary device 81 either does not perform control over its height position or movement, or it does not control its height position but only controls its movement. On the other hand, the second auxiliary device 82 does not control its height position but only controls its movement. By performing such control, the first and second auxiliary devices 81 and 82 are in contact with the main body 21 of the transport device 2 (the first auxiliary device 81 pushes up the transport arm 22 from below, and the second auxiliary device 82 is connected to the upper surface of the main body 21 of the transport device 2), and only the repulsive force on the coil 3 on the floor surface 141 side is applied. Then, to keep this repulsive force constant, power supply control is implemented to the coils 3 located below the main bodies 83 and 84 of the first and second auxiliary devices 81 and 82. As a result, the first auxiliary device 81 assists in the levitation of the transport device 2 by pushing up the transport arm 22. The second auxiliary device 84 also assists in the levitation of the transport device 2 by pulling up the main body 21 of the transport device 2. On the other hand, since the main body 21 of the transport device 2 is controlled to move at a height position of levitation amount H, the first and second auxiliary devices 81 and 82 are restricted from freely rising by the reaction force from the transport arm 22 and main body 21 of the transport device 2, and move at height positions of levitation amounts H1 and H2, respectively. The first and second auxiliary devices 81 and 82 may also perform only lateral movement control. Alternatively, the second auxiliary device 82, which is connected to the upper surface of the main body 21 of the conveying device 2, may not be controlled to move laterally, but rather power supply control to the coil 3 may be performed so that the force acting in the forward, backward, left, and right directions remains constant. In this case, the resultant force applied to the second auxiliary device 82 by the magnetic field on the coil 3 side will be zero, and it will move in accordance with the movement of the conveying device 2.As shown in Figure 8, the amount of buoyancy H during transport of the transport device 2 is smaller than the amounts of buoyancy H1 and H2 during transport of the first and second auxiliary devices 81 and 82, and the lower surface of the main body 21 of the transport device 2 is positioned lower than the lower surfaces of the main bodies 83 and 84 of the first and second auxiliary devices 81 and 82.

[0076] The power supply control described above for the coil 3 in the area where the first and second auxiliary devices 81 and 82 are positioned in contact with the transport device 2 is controlled in the vertical direction to supply a predetermined power corresponding to a preset repulsive force. That is, the control unit 5 only determines whether the predetermined power is being supplied. In other words, as power supply control for the coil 3 in the area where the first and second auxiliary devices 81 and 82 are positioned in contact with the transport device 2, the control unit 5 performs only open-loop control without using feedback. Therefore, while connected to the transport device 2, no horizontal movement control is performed for the first and second auxiliary devices 81 and 82, and they move subordinate to the transport device 2. The same applies to the case where the second auxiliary device 82 does not perform lateral movement control, but controls the force acting in the front, back, left, and right directions to remain constant, in order to supply predetermined power to the coil 3. On the other hand, for the first auxiliary device 82, the same power supply control as in the conventional method is performed for lateral movement of the coil 3. Furthermore, in the second auxiliary device 82, when controlling movement in the lateral direction, the same power supply control as in the conventional method is performed.

[0077] Next, a second control method will be described for the case where the transport of the covering CR is assisted by the first and second auxiliary devices 81 and 82. In this method, the first and second auxiliary devices 81 and 82 are controlled to supply power to the coil 3 so that they move at height positions of levitation amounts H1 and H2 during transport, as described in the conventional method explained using Figures 3(a) and (b). On the other hand, the main body 21 of the transport device 2 is controlled to supply power to the magnetic force acting on the magnet units 26 and 27 so that the tangential moment directed upward is constant at the tip of the main body 21. In this case, the main body 21 of the transport device 2 is controlled to move laterally. Even in this case, the power supply control to the coil 3 to apply a constant moment to the main body 21 of the transport device 2 can be an open loop.

[0078] With the first and second auxiliary devices 81 and 82 performing the above-described auxiliary operations, the transport device 2 does not need to teach the target position for positioning the forks 23 at a location where the required substrate W and covering CR can be transferred. Furthermore, since the transport device 2 transports the covering CR with the assistance of the first and second auxiliary devices 81 and 82 rather than on its own, the power supply amount to each coil 3 can remain at the same level as when transporting the substrate W. In addition, when transporting objects heavier than the substrate W, the increase in occupied area is suppressed compared to when the main body 21 is enlarged, thus suppressing an increase in the footprint of the substrate transport module 14.

[0079] <Transportation and Placement Operations for Covering CR> Below, an example of the transport operation in which a clean covering CR is transported to and installed in the processing module 11r by the first and second auxiliary devices 81 and 82 and the transport device 2 will be explained using Figures 9A to 9I. In these figures, the shape of the covering CR is shown as a disc rather than an actual ring. In each figure, the movement trajectory of the transport device 2 and the first and second auxiliary devices 81 and 82 is shown with a solid arrow, and the subsequent direction of movement is shown with a dashed arrow, showing an example of a pre-set movement path for the transport device 2 and the first and second auxiliary devices 81 and 82.

[0080] First, the transport device 2 waits in a floating state at a preset CR transfer waiting position with the transport arm 22 independently inserted into the stocker module 10, in an operation similar to that of the substrate W transfer operation described above (Figure 9A). At this CR transfer waiting position, the transport device 2 is waiting with the fork 23 positioned below the covering CR, which has been previously lifted by the support pin 10b. Then, in order to assist the transport device 2 before it receives the covering CR from the support pin 10b, the second auxiliary device 82, which is waiting in the waiting area of ​​the floor surface 141, is moved to a preset second connection position of the stocker module 10 (Figure 9B, step of making contact with the moving body). This second connection position is a position where the second auxiliary device 82 can be connected to the transport device 2 positioned at the CR transfer waiting position, and is a position where the tip of the connecting part 86 is adjacent to, for example, in contact with, the center of the rear peripheral edge of the main body 21 of the transport device 2 positioned at the CR transfer waiting position. Next, the second auxiliary device 82 turns on the detachable member 86m and connects the connecting part 86 to the main body part 21, thereby assisting the transport device 2.

[0081] The conveying device 2, assisted by the second auxiliary device 82, receives the covering CR from the support pin 10b and retracts to the auxiliary switching position (Figure 9C, the process of moving the mobile body along the running surface while holding the object to be conveyed, and the process of moving the mobile body along the running surface while being assisted in floating the mobile body). The auxiliary switching position is a position for switching the assistance from the first and second auxiliary devices 81 and 82, and is a position in which assistance can be received from either the first or second auxiliary devices 81 and 82. The auxiliary switching position is set not only for the stocker module 10 but also for each processing module 11. The CR handover waiting position, the second connection position, and the first connection position described later are similarly set for the stocker module 10 and each processing module 11. This stocker auxiliary switching position is a position in which the conveying arm 22 can be positioned on the floor surface 141 to the extent that the first auxiliary device 81 can be placed below the conveying arm 22 to provide pressing assistance. The auxiliary switching position is a position in which the auxiliary second auxiliary device 82 is positioned on the floor surface 141 and can receive a magnetic field, and the auxiliary second auxiliary device 82 does not come into contact with the right side wall 142 of the floor surface 141.

[0082] To assist the transport device 2 which has moved to the auxiliary switching position, the first auxiliary device 81, which is waiting in the standby section, is moved to a preset first connection position of the stocker module 10 (stocker first connection position) (Figure 9D). This stocker first connection position is a position in which the first auxiliary device 81 can push up the transport arm 22 of the transport device 2 which is positioned at the auxiliary switching position, and is a position in which the pressing part 85 is positioned below the transport arm 22.

[0083] When the first auxiliary device 81 is positioned at the first connection position of the stocker, the attachment / detachment member 86m is turned off and separated from the main body 21, releasing the auxiliary operation of the second auxiliary device 82, while simultaneously starting the assistance of the first auxiliary device 81 (Figure 9E, the process of making contact with the moving body). The second auxiliary device 82, whose auxiliary operation has been released, rotates 90 degrees counterclockwise and moves backward to the standby section. The transport device 2, assisted by the first auxiliary device 81, moves in front of the processing module 11r, which is the destination of the transport, by rotating 90 degrees counterclockwise while moving backward and moving along the right side wall 142 (the process of running the moving body along the running surface while holding the object to be transported, and the process of running the moving body along the running surface while assisting the lift of the moving body), and then stops at a position away from the processing module 11r (Figure 9F).

[0084] Next, the transport device 2 rotates 90 degrees clockwise and moves forward, waiting in a floating state at the auxiliary switching position of the processing module 11r (Figure 9G). Then, the second auxiliary device 82 moves to the second connection position of the processing module 11r, connects to the main body 21, and assists the transport device 2 (Figure 9H). When the transport device 2 is assisted by the second auxiliary device 82, the first auxiliary device 81 moves toward the waiting position (Figure 9H). Then, the transport device 2, assisted only by the second auxiliary device 82, moves forward to the CR handover waiting position of the processing module 11r, and hands over the covering CR to the mounting table 111 of the processing module 11r via the lifting pin 66 (Figure 9I). The above describes the transport operation of a clean covering CR, but the transport operation of a used covering CR to be removed from the processing module 11 can be done by reversing this transport operation of the covering CR.

[0085] (Modification) In this embodiment, the coil 3 is provided only within the floor portion 141, but it is not limited to this, and the coil 3 may also be provided in the load lock module 13, processing module 11, and stocker module 10 so that the transport device 2 and the first auxiliary device 81 can enter and move into these. The stocker module 10 is not limited to one, and multiple modules may be provided, and it may be provided in a relatively large area to also serve as a standby position for the first and second auxiliary devices 81 and 82.

[0086] Furthermore, the standby areas for the first and second auxiliary devices 81 and 82 do not need to be limited to the innermost area of ​​the floor surface 141 as described above, and multiple standby areas may be provided distributed among the substrate transport modules 14. Alternatively, the standby areas for the first and second auxiliary devices 81 and 82 may be created by removing one of the multiple processing modules 11 and extending the substrate transport module 14 to that area. Moreover, it is not necessary to provide special standby areas, and the first and second auxiliary devices 81 and 82 waiting for auxiliary operation may be placed in various locations on the floor surface 141 so as not to interfere with the transport operation of the transport device 2.

[0087] When connecting the first and second auxiliary devices 81 and 82 to the transport device 2, a load sensor or the like may be provided at the tip of the pressing part 85 or the connecting part 86, and feedback control may be performed to control the repulsive force of the first and second auxiliary devices 81 and 82 so that the load sensor reads a constant value.

[0088] On the other hand, the first and second auxiliary devices 81 and 82 in the embodiment described using Figures 7 and 8 perform open-loop control during auxiliary operation. As a result, as shown in Figures 10A and 10B, even if there is a mounting error in the height direction of the tile 143, the first auxiliary device 81, for example, is controlled to generate a constant repulsive force, so the covering CR can be transported stably. Specifically, if there is a positional displacement in the height direction of the tile 143, the position of the coil 3 and Hall sensor will be shifted. If the amount of levitation of the main body 83 is controlled by feedback control, the amount of levitation h1 will be maintained at the position of the first auxiliary device 81 in accordance with the positional displacement of the upper surface of the tile 143. Therefore, the first auxiliary device 81, which moves up and down in accordance with the positional displacement of the upper surface of the tile 143, may tilt the transport device 2 and may not be able to maintain a horizontal posture.

[0089] However, with open-loop control as in this embodiment, the first and second auxiliary devices 81 and 82 are not controlled by positional control but are controlled only by a preset levitation force. Therefore, they are not affected by the displacement of the tiles 143 and the covering CR can be transported stably. While there are advantages as described above, similar to the transport device 2, the transport device 2 may be assisted by performing positional control using feedback control, for example, by levitating the first auxiliary device 81 with the levitation amount H1 described above, or by positioning it at a fixed position in the horizontal direction relative to the transport device 2 so as to reliably follow the horizontal movement of the transport device 2.

[0090] In this embodiment, the transport device 2 is shown as an example of transporting a covering CR with the assistance of the first and second auxiliary devices 81 and 82, but it may also transport other objects heavier than the substrate W. Other objects to be transported may include other parts such as clamp rings used in the processing module 11. In this embodiment, the transport device 2 and the first and second auxiliary devices 81 and 82 transported the substrate W and objects to be transported in a vacuum atmosphere such as the substrate transport module 14, but it is also possible to transport them in an atmospheric atmosphere by laying tiles 143 in an atmospheric transport module 12, for example.

[0091] As shown in this embodiment, it is not always necessary to provide assistance with the auxiliary devices 81 and 82 while the transport device 2 is supporting the covering CR. For example, when the transport device 2 is positioned such that the direction of the magnetic field of the coil 3 and the direction of the magnetic fields of the magnet units 24 to 27 are offset by 45 degrees in a plan view, the repulsive force will be weaker than the repulsive force when these directions are parallel (Figures 3(a) and 3(b)). Therefore, assistance with the auxiliary devices 81 and 82 is only necessary when the transport device 2 is positioned such that these directions are not parallel and is supporting the covering CR (for example, during transport operations involving rotation as shown in Figures 9B and 9F).

[0092] In this embodiment, the first and second auxiliary devices 81 and 82 were used alternately to assist the conveying device 2, but this is not limited to this. Assistance may be provided by only one of them, or the first and second auxiliary devices 81 and 82 may be increased to three or more units to assist the conveying device 2. Furthermore, the first auxiliary device 81 does not necessarily need to have a pressing section 85; pressing may be performed with the upper surface of the main body 83. Thus, the first and second auxiliary devices 81 and 82 may take on other forms. Moreover, the invention is not limited to the first and second auxiliary devices 81 and 82; the covering CR conveying operation of the conveying device 2 may be assisted using auxiliary devices that assist by other methods. Modifications are shown below.

[0093] (First Modification) As an example of another auxiliary method for the second auxiliary device 82, it is not necessary to use connection by a detachable member 86m, for example, the connecting part 86A and the conveying device 2 may be mechanically connected, as shown in Figures 11 and 12. Figures 11 and 12 are a plan view and a partial longitudinal front view showing the conveying device 2A and two auxiliary devices 82A that are mechanically connected in this manner.

[0094] As shown in the figure, the base end of the transport arm 22A of the transport device 2A is provided with two connecting holes 22p for connecting to the connecting portion 86 into which each auxiliary device 82A is inserted. Each connecting hole 22p is provided as an opening at an opposing position on each side of the transport arm 22A and is recessed toward the other connecting hole 22p. Each auxiliary device 82A is connected by moving forward toward the transport arm 22A from the side of the transport arm 22A with the tip of its respective connecting portion 86A facing the connecting hole 22p, and inserting the tip of the connecting portion 86A into the connecting hole 22p (Figures 11 and 12). In this state, the inserted state of the tip of each connecting portion 86A is maintained by the frictional force acting between it and the connecting hole 22p. Here, in order to suppress the generation of particles when inserting and removing the connecting portion 86A from the connecting hole 22p, an O-ring (not shown) may be provided in the connecting hole 22p.

[0095] (Second Modification) Furthermore, the parts of the transport device 2 supported by the first and second auxiliary devices 81 and 82 do not necessarily have to be the lower surface of the transport arm 22 or the rear peripheral edge of the main body 21 as described above, but may be other parts. For example, Figure 13 is a plan view showing another auxiliary method using the second auxiliary device 82.

[0096] In Figure 13, the second auxiliary device 82 may be provided by connecting a magnet unit 86a to the lower surface of the transport arm 22 (Figure 13). To enable this connection, the transport arm 22 is made of, for example, a ferromagnetic metal. On the other hand, the detachable member 86m on the second auxiliary device 82 side is positioned above the connecting portion 86 and can be connected to the transport arm 22. In order to connect to the lower surface of the transport arm 22 of the transport device 2 which has been lifted by a lift amount H, the height position of the upper surface of the connecting portion 86 of the second auxiliary device 82 which has been lifted by a lift amount H2 during transport is aligned with the height position of the lower surface of the transport arm 22.

[0097] As shown in Figure 13, when assisting the transport device 2, the second auxiliary device 82 floats up with a levitation amount smaller than the levitation amount H2 when connecting to the transport arm 22, and faces the transport arm 22 from a direction perpendicular to the transport device 2 (sideways) as the transport device 2 floats and remains stationary. Then it moves forward toward the transport arm 22 from the side. When the connecting part 86 is positioned below the transport arm 22, the second auxiliary device 82 stops moving forward and starts its assisting operation. The start of assistance means that after the second auxiliary device 82 is controlled to have a constant levitation force, the detachable member 86m is turned ON and the connecting part 86 is connected to the transport arm 22. In this example, the second auxiliary device 82 can assist so that the connecting part 86 pushes up the transport arm 22 while the connecting part 86 is integrated with the transport arm 22.

[0098] Furthermore, when performing auxiliary operations from the side of the transport arm 22, the state in which the second auxiliary device 82 makes contact is not limited to magnetic connection using a detachable member 86m. For example, a member corresponding to the cover 85a on the upper surface of the pressing portion 85 of the first auxiliary device 81, as explained using Figure 8, may be attached to the upper surface of the connecting portion 86 shown in Figure 13. In this case, the first auxiliary device 81 moves in accordance with the operation of the transport arm 22 due to the frictional force acting between the cover on the second auxiliary device 82 side and the lower surface of the transport arm 22.

[0099] Furthermore, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, substituted, modified and combined in various ways without departing from the scope and spirit of the appended claims.

[0100] CR Covering S1 Transport Space W Substrate 1 Substrate Transport System 2 Transport Module 3 Coil 28 Magnet 81, 82 First and Second Auxiliary Devices 100 Semiconductor Manufacturing Equipment 140 Chamber 140n Transport Space

Claims

1. A substrate transport system comprising a semiconductor manufacturing apparatus for processing substrates, and for transporting the substrates in a transport space, the system comprising: a substrate transport chamber comprising the transport space and equipped with a plurality of electromagnets for forming a magnetic field with respect to the travel surface; a mobile body having a magnet for levitating from the travel surface by the action of the magnetic field and configured to move along the travel surface while holding the substrate; and an auxiliary mobile body having a magnet for levitating from the travel surface by the action of the magnetic field and configured to move along the travel surface while in contact with the mobile body when the mobile body is moving along the travel surface holding an object heavier than the substrate, thereby assisting the levitation of the mobile body.

2. The substrate transport system according to claim 1, wherein the movable body comprises a main body on which the magnet is provided, and a transport arm provided so as to extend horizontally from the main body and connected to the substrate transport chamber for holding the substrate or the object to be transported, and the auxiliary movable body assists in the levitation of the movable body by pushing up the transport arm from the lower side to levitate.

3. The substrate transport system according to claim 1, wherein the moving body comprises a main body on which the magnet is provided, and the auxiliary moving body assists in the levitation of the moving body by levitating while connected to the main body of the moving body.

4. The substrate transport system according to claim 3, wherein a processing chamber for processing the substrate is connected to the substrate transport chamber, the movable body is provided so as to extend horizontally from the main body and is equipped with a transport arm for holding the substrate or the object to be transported, and the auxiliary movable body is connected to the main body of the movable body during the period when the transport arm is inserted into the processing chamber in order to transfer the substrate or the object to be transported between it and the processing chamber.

5. A substrate transport system according to claim 1, comprising a control unit that controls the movement of the moving body and the auxiliary moving body by adjusting the magnetic field formed by the plurality of electromagnets, wherein the control unit performs control to move the moving body along a preset movement path, and performs control to maintain a constant repulsive force in a direction perpendicular to the running surface so that the auxiliary moving body moves in a manner dependent on the movement of the moving body while in contact with the moving body.

6. The substrate transport system according to claim 1, wherein, when viewed from a direction opposite to the traveling surface, the area occupied by the auxiliary moving body is less than or equal to the area occupied by the moving body.

7. The substrate transport system according to claim 1, further comprising a standby unit for which the auxiliary mobile body is kept in a position that does not interfere with the transport path used by the mobile body to transport the substrate or the object to be transported.

8. The substrate transport system according to claim 1, wherein the object to be transported is a component connected to the substrate transport chamber and placed in a processing chamber that processes the substrate.

9. A semiconductor manufacturing apparatus comprising a substrate transport system according to any one of claims 1 to 8, and a processing chamber connected to the substrate transport chamber for processing the substrate.

10. A method for transporting a substrate using a substrate transport system for transporting a substrate in a transport space, comprising: a substrate transport chamber comprising the transport space and equipped with a plurality of electromagnets for forming a magnetic field with respect to a travel surface; a mobile body having a magnet for levitating from the travel surface by the action of the magnetic field and configured to move along the travel surface while holding the substrate; an auxiliary mobile body having a magnet for levitating from the travel surface by the action of the magnetic field and configured to assist in the levitation of the mobile body when the mobile body is moving along the travel surface while holding an object to be transported that is heavier than the substrate; the method for transporting a substrate comprising: forming a magnetic field with respect to the travel surface and driving the mobile body along the travel surface while holding the object to be transported by the action of the magnetic field; and further, the method for driving the mobile body comprising: forming a magnetic field with respect to the travel surface and bringing the auxiliary mobile body into contact with the mobile body by the action of the magnetic field; and driving the mobile body along the travel surface while the levitation of the mobile body is assisted by the contacted auxiliary mobile body.

11. The method according to claim 10, in the step of moving the moving body along a running surface while assisting the levitation of the moving body, the method is as follows: With respect to the moving body, the magnetic field formed by a plurality of electromagnets is adjusted so as to move the moving body along a predetermined path; With respect to the auxiliary moving body, the magnetic field formed by a plurality of electromagnets is adjusted so as to maintain a constant repulsive force in a direction perpendicular to the running surface so as to move the auxiliary moving body in conjunction with the movement of the moving body while in contact with the moving body.

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