Apparatus for transferring substrate and method for transferring substrate

Abstract

To provide a technique for cleaning a substrate transfer module for transferring a substrate by using magnetic levitation.SOLUTION: In an apparatus for transferring a substrate to a substrate processing chamber in which the substrate is processed, a substrate transfer chamber has a floor surface part provided with a first magnet, and a sidewall part formed with an opening to which the substrate processing chamber is connected. The substrate transfer module includes a substrate holder and a second magnet, and is configured to be movable in the substrate transfer chamber by magnetic levitation using a repulsive force acting between the first magnet and the second magnet. The heating unit is configured to heat the substrate transfer module to release a contaminant adhering to a surface of the substrate transfer module.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for transporting a substrate and a method for transporting a substrate. [Background technology]

[0002] For example, in an apparatus (wafer processing apparatus) that processes semiconductor wafers (hereinafter also referred to as "wafers"), which are substrates, the wafers are transported between a carrier that stores the wafers and a wafer processing chamber where the processing is performed. Wafer transport mechanisms of various configurations are used to transport the wafers. The applicant is currently developing a wafer processing apparatus that uses a substrate transfer module that utilizes magnetic levitation to transfer substrates.

[0003] Meanwhile, the space within the wafer processing equipment where wafers are transported contains trace amounts of various contaminants, such as particles generated by contact between the wafer and the equipment or between the equipment, and chemicals used in wafer processing. If these contaminants adhere to and accumulate on the substrate transport module, they can contaminate the wafers being transported.

[0004] For example, Patent Document 1 describes a technology in which the temperature of components constituting a stage on which a substrate to be processed is placed is increased in a reduced-pressure processing apparatus, and fine particles are scattered by thermal stress and thermophoretic force. However, Patent Document 1 does not describe a method for dealing with contamination of a substrate transfer module that uses magnetic levitation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-101539 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure provides techniques for cleaning substrate transfer modules that utilize magnetic levitation to transfer substrates. [Means for solving the problem]

[0007] The present disclosure provides an apparatus for transporting a substrate to a substrate processing chamber in which processing of the substrate is performed, the apparatus comprising: a substrate transfer chamber having a floor portion on which a first magnet is provided and a sidewall portion to which the substrate processing chamber is connected and having an opening formed therein through which substrates are transferred in and out of the substrate processing chamber; a substrate transfer module including a substrate holder that holds the substrate and a second magnet that generates a repulsive force between the second magnet and the first magnet, the substrate transfer module being movable within the substrate transfer chamber by magnetic levitation using the repulsive force; and a heating unit that heats the substrate transfer module to release contaminants adhering to the surface of the substrate transfer module. [Effects of the Invention]

[0008] According to the present disclosure, a substrate transfer module that uses magnetic levitation to transfer substrates can be cleaned. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing a first configuration example of a wafer processing system. [Figure 2] FIG. 2 is a plan view showing a first configuration example of a transfer module. [Figure 3] FIG. 10 is a perspective view showing an example of the configuration of a transport module and tiles. [Figure 4] FIG. 1 is a plan view showing an example of the operation of the wafer processing system. [Figure 5A] FIG. 2 is a first vertical cross-sectional side view showing a first configuration example of a heating unit. [Figure 5B] FIG. 10 is a second vertical cross-sectional side view showing the first configuration example of the heating unit. [Figure 6] FIG. 10 is a vertical cross-sectional side view showing a second configuration example of the heating unit. [Figure 7A]FIG. 10 is a first vertical cross-sectional side view showing a third configuration example of the heating unit. [Figure 7B] FIG. 10 is a second vertical cross-sectional side view showing a third configuration example of the heating unit. [Figure 8] FIG. 10 is a vertical cross-sectional side view showing a fourth configuration example of the heating unit. [Figure 9] FIG. 10 is a plan view showing a second configuration example of the wafer processing system. [Figure 10] FIG. 10 is a plan view showing a second configuration example of the transfer module. [Figure 11] FIG. 10 is a plan view showing a third configuration example of the wafer processing system. [Figure 12] FIG. 10 is a block diagram showing an example of the configuration of a correction mechanism for correcting positional deviation caused by heating of a transfer module. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Wafer processing system> The configuration of an apparatus for transporting a substrate according to an embodiment of the present disclosure will be described below with reference to Fig. 1. The apparatus for transporting a substrate is provided in a wafer processing system 101. 1 shows a multi-chamber type wafer processing system 101 equipped with a plurality of wafer processing chambers 110, which are substrate processing chambers for processing wafers W. As shown in Fig. 1, the wafer processing system 101 is equipped with a load port 141, an atmospheric transfer chamber 140, a load lock chamber 130, a vacuum transfer chamber 160, and a plurality of wafer processing chambers 110. In the following description, the side on which the load port 141 is provided is referred to as the front side.

[0011] In the wafer processing system 101, the load port 141, atmospheric transfer chamber 140, load lock chamber 130, and vacuum transfer chamber 160 are arranged horizontally in this order from the front side. In addition, multiple wafer processing chambers 110 are arranged side by side on the left and right sides of the vacuum transfer chamber 160 when viewed from the front side.

[0012] The load port 141 is configured as a mounting table on which carriers C, which accommodate wafers W to be processed, are placed, and four carriers C are arranged side by side in the left-right direction when viewed from the front side. For example, a FOUP (Front Opening Unified Pod) or the like can be used as the carriers C.

[0013] The atmospheric transfer chamber 140 has an atmospheric pressure (normal pressure) atmosphere, and for example, a downflow of clean air is formed. A wafer transfer mechanism 142 for transferring wafers W is provided inside the atmospheric transfer chamber 140. The wafer transfer mechanism 142 inside the atmospheric transfer chamber 140 is configured, for example, by an articulated arm. This wafer transfer mechanism 142 transfers wafers W between the carrier C and the load lock chamber 130. An alignment chamber (not shown) for aligning wafers W is provided, for example, on the left side of the atmospheric transfer chamber 140.

[0014] Between the vacuum transfer chamber 160 and the atmospheric transfer chamber 140, for example, two load lock chambers 130 are installed side by side. The load lock chamber 130 has lift pins 131 that push up the loaded wafer W from below and hold it. For example, three lift pins 131 are provided at equal intervals along the circumferential direction and are configured to be freely movable up and down. Note that lift pins 113 and 143, which will be described later, are configured in a similar manner.

[0015] The load lock chamber 130 is configured to be able to switch between an atmospheric pressure atmosphere and a vacuum atmosphere. The load lock chamber 130 and the atmospheric transfer chamber 140 are connected via a gate valve 133. The load lock chamber 130 and the vacuum transfer chamber 160 are also connected via a gate valve 132.

[0016] The vacuum transfer chamber 160 corresponds to the substrate transfer chamber of the present disclosure. As shown in FIG. 1, the vacuum transfer chamber 160 is configured as a housing that is elongated in the front-to-rear direction and has a rectangular shape in a plan view. The vacuum transfer chamber 160 is depressurized to a vacuum atmosphere by a vacuum exhaust mechanism (not shown). The vacuum transfer chamber 160 may also be connected to an inert gas supply unit (not shown) that supplies an inert gas (e.g., nitrogen gas) so that the depressurized vacuum transfer chamber 160 is constantly supplied with the inert gas. In the wafer processing system 101 of the example shown in FIG. 1, four wafer processing chambers 110 are connected to each of the left and right side walls of the vacuum transfer chamber 160 via gate valves 111, for a total of eight wafer processing chambers 110. Wafers W are loaded and unloaded between the vacuum transfer chamber 160 and the wafer processing chambers 110 through openings that are opened and closed by the gate valves 111.

[0017] Each wafer processing chamber 110 is depressurized to a vacuum atmosphere by a vacuum exhaust mechanism (not shown). A mounting table 112 is provided inside each wafer processing chamber 110, and a predetermined process is performed on the wafer W while it is placed on the mounting table 112. Examples of processes performed on the wafer W include etching, film formation, cleaning, and ashing.

[0018] For example, if the wafer W is to be processed while being heated, a heater is provided on the mounting table 112. If the process to be performed on the wafer W uses a processing gas, a processing gas supply unit constituted by a shower head or the like is provided in the wafer processing chamber 110. Note that these heaters and processing gas supply units are not shown in the drawings. The mounting table 112 is also provided with lift pins 113 for transferring the wafer W when it is loaded or unloaded. The wafer processing chamber 110 corresponds to the substrate processing chamber in this embodiment.

[0019] <Transport module 30> In the vacuum transfer chamber 160 having the above-described configuration, the wafer W is transferred using a magnetic levitation transfer module (substrate transfer module) 30. The transfer module 30 of the example shown in FIGS. 2 and 3 includes a main body 31 that is rectangular in plan view. The main body 31 is provided with an arm 32 that holds the wafer W horizontally. The arm 32 is provided so as to extend horizontally from a base end on the main body 31 side. The tip of the arm 32 is provided with a fork that can be arranged to surround from the left and right an area where the three lift pins 131 and 113 are provided. The fork corresponds to the substrate holder in the transfer module 30.

[0020] The arm portion 32 is configured to be long enough to transfer the wafer W to the mounting table 112 by opening the gate valve 111 and inserting it into the wafer processing chamber 110 while the main body portion 31 is positioned within the vacuum transfer chamber 160. Furthermore, a module-side magnet 33 is provided inside the main body 31 of the transfer module 30, and an example of its configuration will be described later with reference to FIG.

[0021] <Magnetic levitation mechanism> 3, a plurality of tiles (transfer tiles) 10 are provided on the floor of the vacuum transfer chamber 160. These tiles 10 are provided in a transfer area of ​​the transfer module 30, from a transfer position (opposite the load lock chamber 130) for transferring the wafer W between the external atmospheric transfer chamber 140 and the vacuum transfer chamber 160, to just before the wafer processing chamber 110. Furthermore, if the transfer area is set so that the transfer module 30 can move into the load lock chamber 130 or the wafer processing chamber 110, tiles 10 are also provided on the floor of the load lock chamber 130 or the wafer processing chamber 110.

[0022] A plurality of moving surface side coils 11 are arranged inside each tile 10. The moving surface side coils 11 generate a magnetic field when power is supplied from a power supply unit (not shown). The moving surface side coils 11 correspond to the first magnet of the present disclosure.

[0023] Meanwhile, multiple module-side magnets 33, each composed of, for example, permanent magnets, are arranged inside the transport module 30. A repulsive force (magnetic force) acts between the module-side magnets 33 and the magnetic field generated by the moving surface-side coils 11. This action allows the transport module 30 to be magnetically levitated relative to the moving surface on the upper surface side of the tile 10. The module-side magnets 33 provided in the transport module 30 correspond to the second magnet of the present disclosure.

[0024] Furthermore, the tile 10 can change the state of the magnetic field by adjusting the position where the magnetic field is generated and the strength of the magnetic force using the multiple moving surface side coils 11. By controlling this magnetic field, it is possible to move the transport module 30 in a desired direction on the moving surface, adjust the levitation distance from the moving surface, and adjust the orientation of the transport module 30. Control of the magnetic field on the tile 10 side is performed by selecting the moving surface side coils 11 to which power is supplied and adjusting the amount of power supplied to the moving surface side coils 11.

[0025] The multiple module-side magnets 33 may be configured with coils that function as electromagnets and are supplied with power from a battery provided inside the transport module 30. The module-side magnets 33 may also be configured with both permanent magnets and coils.

[0026] 1 and 3, the length of the short side of the rectangular vacuum transfer chamber 160 in plan view is such that two transfer modules 30 holding wafers W can pass each other when lined up side by side. In addition, the length of the short side of the vacuum transfer chamber 160 in this example is shorter than the length from the main body 31 to the tip of the wafer W when the transfer module 30 holds the wafer W (the total length of the transfer module 30 when holding the wafer W). In this example, the wafer W is transferred using multiple transfer modules 30 provided in the vacuum transfer chamber 160. The vacuum transfer chamber 160, which is equipped with the transfer module 30 and to which the wafer processing chamber 110 is connected, corresponds to the device for transferring substrates according to the present disclosure.

[0027] <Control unit 5> The wafer processing system 101 includes a control unit 5. The control unit 5 is configured by a computer having a CPU and a storage unit, and controls each unit of the wafer processing system 101. The storage unit stores a program that includes a group of steps (commands) for controlling the movement of the transfer module 30 and the operation of the wafer processing chamber 110. This program is stored in a storage medium such as a hard disk, compact disk, magnetic optical disk, memory card, or nonvolatile memory, and is installed from there into the computer.

[0028] <Wafer W Transfer Operation> Next, an example of a wafer W transfer operation in the wafer processing system 101 having the above-described configuration will be described. First, a carrier C containing a wafer W to be processed is placed on the load port 141, and the wafer W is removed from the carrier C by the wafer transfer mechanism 142 in the atmospheric transfer chamber 140. Next, the wafer W is transferred to an alignment chamber (not shown), where alignment of the wafer W is performed. Furthermore, when the wafer W is removed from the alignment chamber by the wafer transfer mechanism 142, the gate valve 133 is opened.

[0029] When the wafer transfer mechanism 142 enters the load lock chamber 130, the lift pins 131 push up and receive the wafer W. After that, when the wafer transfer mechanism 142 retreats from the load lock chamber 130, the gate valve 133 is closed. Furthermore, the atmosphere inside the load lock chamber 130 is switched from atmospheric pressure to a vacuum atmosphere.

[0030] Once the load lock chamber 130 is in a vacuum atmosphere, the gate valve 132 is opened. At this time, inside the vacuum transfer chamber 160, the transfer module 30 is waiting in a position facing the load lock chamber 130 near the connection position of the load lock chamber 130. Then, using the magnetic field generated by the moving surface side coil 11 provided on the tile 10, the transfer module 30 is raised by magnetic levitation.

[0031] 1, the arm unit 32 of the transfer module 30 is advanced into the load lock chamber 130 and positioned below the wafer W supported by the lift pins 131. The lift pins 131 are then lowered to transfer the wafer W to the fork of the arm unit 32.

[0032] Next, the arm unit 32 holding the wafer W is withdrawn from the load lock chamber 130, and the transfer module 30 is retracted to a position to the side of the wafer processing chamber 110 where the processing of the wafer W is to be performed. At this time, the main body 31 of the transfer module 30 moves past the position where the gate valve 111 is disposed to the rear side. By this operation, the tip side of the arm unit 32 holding the wafer W is positioned to the side of the gate valve 111.

[0033] In this way, when the tip of the arm unit 32 reaches the side of the gate valve 111, in addition to the retreating operation, the tip of the arm unit 32 is rotated so as to face the gate valve 111. Next, the gate valve 111 is opened, and while rotating so as to insert the wafer W into the wafer processing chamber 110, the movement direction of the transfer module 30 is switched to forward.

[0034] As described above, the length of the vacuum transfer chamber 160 in the short side direction is shorter than the overall length of the transfer module 30 holding the wafer W. Even in this case, the wafer W can be loaded into the wafer processing chamber 110 within the vacuum transfer chamber 160 by a switching operation that moves the transfer module 30 forward and backward while combining a rotation operation.

[0035] Thereafter, when the transfer module 30 is positioned directly facing the wafer processing chamber 110, it stops rotating and moves straight ahead until the wafer W reaches above the mounting table 112. Thereafter, the wafer W is transferred to the mounting table 112, and the transfer module 30 is retracted from the wafer processing chamber 110. After the gate valve 111 is closed, processing of the wafer W begins.

[0036] That is, the wafer W placed on the mounting table 112 is heated as needed to a preset temperature, and if a processing gas supply unit is provided, a processing gas is supplied into the wafer processing chamber 110. In this way, the desired processing is performed on the wafer W.

[0037] After processing the wafer W for a preset period, heating of the wafer W is stopped and the supply of processing gas is stopped. If necessary, a cooling gas may be supplied into the wafer processing chamber 110 to cool the wafer W. Thereafter, the wafer W is transferred from the wafer processing chamber 110 to the load lock chamber 130 in the reverse order of the loading procedure. Furthermore, after the atmosphere in the load lock chamber 130 is switched to a normal pressure atmosphere, the wafer W in the load lock chamber 130 is removed by the wafer transfer mechanism 142 on the atmospheric transfer chamber 140 side and returned to a predetermined carrier C.

[0038] <Pollutant Release> In the wafer processing system 101 having the configuration described above, particles may be generated due to contact between devices, for example, when the gate valves 132 and 111 are opened or closed. Furthermore, molecules of the process gas supplied into the wafer processing chamber 110 may be adsorbed to the wafer W and then released from the wafer W after being brought into the vacuum transfer chamber 160. The process gas molecules may react with moisture present in small amounts in the vacuum transfer chamber 160 or adsorbed on the surfaces of the devices, forming particles or corrosive substances.

[0039] As will be described later, the inside of the vacuum transfer chamber 160 is constantly evacuated, so these particles and molecules (chemical substances) are discharged to the outside of the vacuum transfer chamber 160. On the other hand, some of the particles and chemical substances may adhere to the surface of the transfer module 30 before being discharged from the vacuum transfer chamber 160.

[0040] If particles or chemicals adhere to the surface of the transfer module 30, accumulate, and then re-scatter, they can contaminate the wafer W. As mentioned above, moisture adsorbed to the surface of the equipment can react with chemicals to form particles or corrosive substances. Therefore, the wafer processing system 101 of this example is equipped with a mechanism for releasing contaminants such as particles, chemicals, and moisture adhering to the surface of the transfer module 30. Note that in this disclosure, moisture is also included in the concept of "contaminants."

[0041] 1 and 3, the mechanism for releasing contaminants is provided in a cleaning area 20 set at the rear end of the vacuum transfer chamber 160. The rear end of the vacuum transfer chamber 160 also serves as a space for the main body 31 to enter when performing a switching operation to load and unload the wafer W into and from the wafer processing chamber 110, which is at the rearmost side when viewed from the load port 141. The cleaning area 20 is provided with a heating unit for heating the transport module 30 to release contaminants from the surface of the transport module 30. Various configuration examples of the heating unit will be described below with reference to FIGS. 5A to 8.

[0042] <Heating part configuration example 1: Heating light source 411> 5A and 5B are vertical cross-sectional side views of the vacuum transfer chamber 160 taken along line AA' in FIG. 4 (the same applies to FIGS. 6 to 8). 5A, a heating light source 411, which is a first configuration example of the heating unit of the present disclosure, is provided on the ceiling of the vacuum transfer chamber 160 in the cleaning region 20. In this example, a plurality of heating light sources 411 are provided on the upper surface side of the ceiling of the wafer processing system 101 so that heating light for heating the surface of the transfer module 30 can be evenly irradiated toward the cleaning region 20. In addition, the region irradiated with the heating light can be adjusted by selecting a heating light source 411 to which power is supplied from a power supply unit (not shown).

[0043] An infrared lamp such as a halogen lamp or an LED (Light Emitting Diode) lamp that emits infrared light can be used as the heating light source 411. Each heating light source 411 may be provided with a lampshade 412 to control the direction of irradiation of the heating light. The multiple heating light sources 411 are arranged on the upper surface side of the ceiling of the vacuum transfer chamber 160 via a cover part 414 and a holder part 413. Between the area where the heating light sources 411 are arranged and the cleaning area 20 set in the vacuum transfer chamber 160, a transmission window 415 made of, for example, quartz glass and which allows heating light to pass through is provided.

[0044] 5A and 5B show an example in which a cooling unit is provided to cool the transfer module 30 to the operating temperature after it has been heated by the heating light source 411. In this example, the cooling unit has a configuration in which a flow path (temperature control fluid flow path 21) through which a refrigerant, which is a temperature control fluid, flows is formed in the tile 10. In this case, the upper surface of the tile 10 serves as the contact surface that comes into contact with the main body 31. A refrigerant supply unit 432 that starts and stops the supply of refrigerant is connected to the temperature control fluid flow path 21.

[0045] The operation of heating the surface of the transfer module 30 in the wafer processing system 101 having the above-described configuration to release contaminants from the surface of the transfer module 30 will be described. When it is time to heat the transport module 30, the main body 31 to be processed is moved to the cleaning area 20, and the main body 31 is placed below the heating light source 411. In the examples shown in FIGS. 4, 5A, and 5B, one transport module 30 is placed, but two transport modules 30 may also be placed.

[0046] The heating of the main body 31 can be performed, for example, after a preset time has elapsed since the previous heating or after a preset number of wafers W have been transferred. 4 shows a state in which the transfer module 30 is placed in the cleaning area 20 in parallel with the operation of transferring wafers W by other transfer modules 30 within the vacuum transfer chamber 160. In this regard, it is preferable to actually heat the transfer module 30 during a period when no wafers W are being transferred within the vacuum transfer chamber 160. Examples of periods when no wafers W are being transferred include a period when wafers W are being processed within the wafer processing chamber 110 and there is a sufficient waiting time, or a period when processing of all wafers W has been completed and there are no wafers W within the vacuum transfer chamber 160 or the wafer processing system 101.

[0047] After placing the transport module 30 (main body 31) in the cleaning area 20, the transport module 30 is floated as shown in FIG. 5A. Then, the heating light source 411 in the area facing the main body 31 is turned on and heating light is emitted. The irradiation of the heating light causes the temperature of the surface of the main body 31 to rise rapidly from room temperature. In this case, the surface of the main body 31 may be heated to a temperature in the range of 75 to 300°C.

[0048] When the temperature of the components of the main body 31 or particles adhering to the surface thereof rises suddenly, a sudden thermal stress is applied, which acts as a force to peel off the particles from the surface of the main body 31. In addition, a large temperature gradient is formed between the surface of the main body 31 and the surrounding atmosphere, which causes thermophoresis, which also acts as a force to peel off the particles from the surface of the main body 31. As these forces are applied, the particles adhering to the surface of the wafer W are released. Furthermore, chemical substances and moisture adhering to the surface of the wafer W are sublimated and vaporized or decomposed by the heating of the main body 31 and are released from the surface of the wafer W.

[0049] Furthermore, the temperature also rises on the underside of the main body 31, which is not irradiated with the heating light, due to heat conduction from the upper side. At this time, heating is performed on the main body 31 in a state where it is floating above the floor of the vacuum transfer chamber 160, and particles and chemical substances are also released from the surface of the main body 31 on the underside due to the mechanism described above.

[0050] Furthermore, a temperature rise occurs on the surface of the arm portion 32 connected to the main body portion 31 due to heat conduction, and particles and chemical substances are released from the surface. In addition, the heating light source 411 may be positioned so that heating light can also be irradiated onto the upper surface of the arm portion 32, or after heating the main body portion 31, the conveying module 30 may be turned around to allow the arm portion 32 to enter the cleaning area 20, thereby directly heating the main body portion 31.

[0051] 5A, one end of an exhaust flow path 161 that constitutes an exhaust unit that evacuates the vacuum transfer chamber 160 may be opened to the floor of the area where the cleaning area 20 is provided. When the cleaning area 20 is set in the vacuum transfer chamber 160, this exhaust flow path 161 can be said to constitute an exhaust unit that evacuates the atmosphere in which the transfer module 30 is heated.

[0052] Particles and chemical substances (contaminants) released from the surface of the transfer module 30 are exhausted to the outside of the vacuum transfer chamber 160 through this exhaust flow path 161. From this perspective, the exhaust flow path 161 also functions as a contaminant removal unit that removes contaminants released from the surface of the transfer module 30. Furthermore, as described above, when an inert gas is constantly supplied into the vacuum transfer chamber 160, the supply flow rate of the inert gas may be increased while the transfer module 30 is being heated to promote exhaust. In this case, the pressure inside the vacuum transfer chamber 160 may increase. In this regard, the influence of pressure fluctuations can be avoided by adjusting the processing schedule and transfer schedule to heat the transfer module 30 during periods when wafer W is not being transferred.

[0053] The transfer module 30 is heated for a preset time, and when the surface of the main body 31 becomes clean, the irradiation of the heating light from the heating light source 411 is stopped. Thereafter, a coolant is supplied from the coolant supply unit 432 to the temperature control fluid flow path 21, and the transfer module 30 is lowered to bring the underside of the transfer module 30 into contact with the tile 10 in the area to which the coolant is being supplied. When the underside of the main body 31 comes into contact with the surface (contact surface) of the cooled tile 10, the entire transfer module 30 (the underside and upper surfaces of the main body 31 and the arm unit 32) is cooled by thermal conduction. This operation quickly cools the transfer module 30 to, for example, room temperature even in the evacuated vacuum transfer chamber 160, allowing the transfer of the wafer W to be resumed.

[0054] If refrigerant is supplied to the temperature control fluid flow path 21 while the transfer module 30 is being heated, there is a risk that scattered contaminants will be attracted by thermophoresis and adhere to the surface of the cooled tile 10. Therefore, by not supplying refrigerant when the transfer module 30 is being heated, contamination of the tile 10 is avoided and recontamination of the transfer module 30, which comes into contact with the tile 10 during cooling, is suppressed.

[0055] <Heating section configuration example 2: induction coil 421> 6 shows a second configuration example of the heating unit of the present disclosure, in which an induction coil 421 for induction heating is provided on the upper surface of the ceiling of the vacuum transfer chamber 160. The induction coil 421 is covered with a cover 422. When power is supplied to the induction coil 421 from a power supply unit (not shown), the induction coil 421 generates a magnetic field in the region below the induction coil 421 inside the vacuum transfer chamber 160.

[0056] On the other hand, when the main body 31 is placed in the cleaning area 20, the upper surface of the main body 31, which faces the induction coil 421, is made of metal. When power is supplied from the power supply unit to the induction coil 421 and a magnetic field is formed in the vacuum transfer chamber 160, the temperature of the upper surface of the main body 31 rises due to induction heating. The heating temperature of the main body 31 and the release of contaminants (particles and chemical substances) from the surfaces of the transfer module 30 (the upper and lower surfaces of the main body 31 and the arm unit 32) are the same as those described with reference to FIG. 5A. Furthermore, the release of contaminants through the exhaust passage 161 and the cooling of the transfer module 30 by contact with the tile 10 through which the refrigerant flows after the release of contaminants are also the same as those described with reference to FIGS. 5A and 5B, and therefore will not be described again. If it is difficult to levitate the transfer module 30 during heating by the induction coil 421, heating may be performed while the transfer module 30 is supported by a plurality of support pins, for example.

[0057] <Heating section configuration example 3: Heat exchange mechanism> 7A shows an example in which a heat medium supply unit 431 is provided as a heating unit to supply a heat medium, which is a temperature-controlling fluid, to a temperature-controlling fluid flow path 21 formed in a tile 10. In this case, while the heat medium is being supplied from the heat medium supply unit 431, the main body 31 is brought into contact with the upper surface (contact surface) of the tile 10, and the surface of the transfer module 30 is heated to a temperature within a range of 75 to 300°C by thermal conduction (FIG. 7A). The tile 10 in which the temperature-controlling fluid flow path 21 is formed and the heat medium supply unit 431 correspond to the heat exchange mechanism in this example. The transfer module 30 is heated for a preset time, and when the surface of the main body 31 becomes clean, the heat medium is switched to a refrigerant supplied from the refrigerant supply unit 432 to cool the transfer module 30 (FIG. 7B).

[0058] <Heating section configuration example 4: resistance heating element 313> In the example shown in FIG. 8, a resistance heating element 313 serving as a heating unit is provided inside the transfer module 30. Furthermore, a power supply unit that supplies power to the resistance heating element 313 is provided inside the transfer module 30. The resistance heating element 313 may be formed of a secondary battery. In this case, a plug for connecting to an external power source may be provided on the main body 31, and the plug may be inserted into an outlet to charge the secondary battery. Alternatively, the secondary battery may be charged by wireless power supply.

[0059] Alternatively, power may be supplied directly to the resistance heating element 313 by a plug-and-outlet mechanism or wireless power supply without providing a secondary battery inside the main body 31. In this case, the plug or wireless power receiving unit corresponds to the power supply unit 314. The resistance heating element 313 and the power supply unit 314 correspond to the heating unit in this example.

[0060] The transfer module 30 can be heated to a temperature in the range of 75 to 300°C by the resistance heating element 313, thereby releasing contaminants from the surface of the transfer module 30. After that, the transfer module 30 is cooled by contact with the tile 10 through which the refrigerant flows, in the same manner as in the example described with reference to FIG. 5B.

[0061] 8 shows an example of a method for removing contaminants released from the transfer module 30 by a method other than discharging the contaminants via the exhaust flow path 161. That is, in this example, a contaminant collection member 22 having a refrigerant flow path 221 formed therein is provided, for example, on the ceiling side of the vacuum transfer chamber 160. A refrigerant supply unit 23 is connected to the refrigerant flow path 221, and a refrigerant, which is a temperature-controlling fluid, can be supplied to the refrigerant supply unit 23.

[0062] This refrigerant adjusts the temperature of the surface of the contaminant capture member 22 to a lower temperature than the temperature of the transfer module 30 heated by the resistance heating element 313. Contaminants released from the surface of the transfer module 30 move toward the contaminant capture member 22 and adhere to the surface of the contaminant capture member 22 due to thermophoresis caused by the temperature gradient formed between the surface of the transfer module 30 and the surface of the contaminant capture member 22. This action allows the contaminants released from the transfer module 30 to be removed from inside the vacuum transfer chamber 160. The contaminant capture member 22 corresponds to the contaminant removal unit in this example.

[0063] Here, either one or both of the configurations of the contaminant removal unit using the exhaust flow path 161 shown in Figures 5A to 7B and the contaminant removal unit using the contaminant capture member 22 shown in Figure 8 can be selected and arranged as necessary. On the other hand, in the examples shown in Figures 5A, 5B and 6, the heating unit (heating light source 411, induction coil 421) is arranged on the ceiling side of the vacuum transfer chamber 160. In this case, the contaminant capture member 22 may be arranged on the side wall of the vacuum transfer chamber 160, for example.

[0064] <Effects> The wafer processing system 101 according to the present disclosure has the following advantages. The surface of the transfer module 30, which uses magnetic levitation to transfer the wafer W, is heated by a heating unit (heating light source 411, induction coil 421, refrigerant supply unit 432 and temperature-control fluid flow path 21, or resistance heating element 313 in the main body 31). Particles adhering to the surface of the wafer W can be released by the thermal stress and thermophoresis caused by this heating. Furthermore, chemical substances adhering to the surface of the wafer W can be released from the surface of the wafer W by sublimation or decomposition caused by heating of the main body 31. In this way, the transfer module 30 can be cleaned by releasing contaminants adhering to the surface.

[0065] <Wafer Processing System 101a> Next, variations in the region where the cleaning region 20 is provided and the timing for heating the transfer module 30a will be described with reference to an example of a wafer processing system 101a shown in Fig. 9. In Figs. 9 to 12 described below, components common to the wafer processing system 101 and transfer module 30 described using Figs. 1 to 8 are denoted by the same reference numerals as those in these figures.

[0066] 9, a cleaning area 20 is provided in a load lock chamber 130 that switches pressure in order to transfer a wafer W between a vacuum transfer chamber 160 and an atmospheric transfer chamber 140. In this respect, the configuration is different from that of the wafer processing system 101 shown in FIGS. 1 and 3, in which the transfer module 30 is heated in the vacuum transfer chamber 160.

[0067] Furthermore, in the wafer processing system 101a, the wafer processing chamber 110, the load lock chamber 130, and the atmospheric transfer chamber 140 have floor portions at approximately the same height as the vacuum transfer chamber 160. Tiles 10 equipped with moving surface side coils 11 are also provided on these floor portions. Therefore, the transfer module 30a can move by magnetic levitation within the wafer processing chamber 110, the load lock chamber 130, and the atmospheric transfer chamber 140. In this respect, the configuration differs from that of the wafer processing system 101 shown in FIGS. 1 and 3, in which the arm unit 32 is inserted into the wafer processing chamber 110 or the load lock chamber 130 to transfer the wafer W.

[0068] Furthermore, the atmospheric transfer chamber 140a in this example has lift pins 143 provided on the floor, and the wafer W is transferred to and from the wafer transfer mechanism 142 via the lift pins 143. The atmospheric transfer chamber 140a corresponds to the "other substrate transfer chamber" in this example.

[0069] <Heating in Load Lock Chamber 130 1> In the wafer processing system 101 of this embodiment, the wafer W is transferred using a transfer module 30a that does not have an arm unit 32 so that the transfer module 30a can easily enter the load lock chamber 130 or the wafer processing chamber 110. As shown in FIG. 10 , the transfer module 30a is configured to hold the wafer W directly on the upper surface of a main body 31. That is, the main body 31 of the transfer module 30a serves as a stage 34, which is a substrate holding unit on which the wafer W is placed and held. For example, the stage 34 is formed in the shape of a flat rectangular plate.

[0070] The transfer module 30a enters the wafer processing chamber 110 or the atmospheric transfer chamber 140 and transfers the wafer W between the lift pins 113 and 143. The transfer module 30a has a slit 341 formed therein to allow the transfer of the wafer W while avoiding interference with the lift pins 113 and 143. The slit 341 is formed along the path along which the lift pins 113 and 143 pass when the stage 34 moves to and from a position below the wafer W held by the lift pins 113 and 143. The slit 341 is also formed so that the direction of entry to the position below the wafer W can be reversed by 180°. This allows the transfer module 30a and the lift pins 113 and 143 to avoid interference with each other and to be vertically arranged so that the centers of the transfer module 30a and the wafer W are aligned.

[0071] In the atmospheric transfer chamber 140 having the above-described configuration, the transfer module 30a moves into the atmospheric transfer chamber 140a via the load lock chamber 130, receives the unprocessed wafer W from the lift pins 143, and transfers the processed wafer W to the lift pins 143. As described above, a clean air downflow is generated within the atmospheric transfer chamber 140a, but there are relatively more particles present therein than in the vacuum transfer chamber 160, which has a vacuum atmosphere. Furthermore, moisture is easily adsorbed onto the transfer module 30a in the atmospheric transfer chamber 140a. Furthermore, chemical substances adhering to the wafer W during processing in the wafer processing chamber 110 may be carried into the atmospheric transfer chamber 140a and react with moisture in the atmosphere or moisture adsorbed onto the transfer module 30a to generate particles or corrosive chemical substances.

[0072] When the transfer module 30a moves between the atmospheric transfer chamber 140a and the vacuum transfer chamber 160, which have different cleanliness levels, there is a risk that contaminants and moisture may be brought into the vacuum transfer chamber 160 or the wafer processing chamber 110 as the transfer module 30a moves. Therefore, when the transfer module 30a moves from the atmospheric transfer chamber 140a to the vacuum transfer chamber 160, the transfer module 30a is heated in the load lock chamber 130 to release the contaminants. At this time, it is preferable that the transfer module 30a is not transferring a wafer W. After the surface of the transfer module 30a is cleaned by heating, the transfer module 30a can be introduced into the vacuum transfer chamber 160 or the wafer processing chamber 110.

[0073] <Heating in Load Lock Chamber 130 2> Next, the wafer processing system 101b shown in FIG. 11 is an example in which vacuum transfer chambers 160 and 160a, each with a different vacuum level, are connected via a load lock chamber 130, and a cleaning area 20 is provided in the load lock chamber 130. For example, when comparing the wafer processing chamber 110a for film formation by PVD (Physical Vapor Deposition) with the wafer processing chamber 110 for film formation by CVD, a higher vacuum level is required for PVD film formation. Also, for example, PVD film formation may be performed consecutively after CVD film formation. Therefore, in the wafer processing system 101b shown in FIG. 11, the first vacuum transfer chamber 160 connected to the CVD wafer processing chamber 110 and the second vacuum transfer chamber 160a connected to the PVD wafer processing chamber 110a are connected via the load lock chamber 130, enabling continuous film formation by CVD and PVD.

[0074] On the other hand, the second vacuum transfer chamber 160a connected to the PVD film deposition system, which requires a high degree of vacuum, may require a higher level of cleanliness than the first vacuum transfer chamber 160. Therefore, the wafer processing system 101b of this example has a cleaning area 20 in the load lock chamber 130 located between the first and second vacuum transfer chambers 160 and 160a. With this configuration, the transfer module 30a can be heated in the load lock chamber 130 to release contaminants when the transfer module 30a moves from the first vacuum transfer chamber 160 to the second vacuum transfer chamber 160a. At this time, it is preferable that the transfer module 30a is not transferring a wafer W. After the surface of the transfer module 30a is cleaned by heating, the transfer module 30a can be introduced into the second vacuum transfer chamber 160a or the wafer processing chamber 110a where PVD film deposition is performed.

[0075] The first vacuum transfer chamber 160 and the second vacuum transfer chamber 160a are configured almost identically, except for the wafer processing chambers 110, 110a connected to their openings. Furthermore, the type of processing performed on wafers W in the wafer processing chambers 110, 110a connected to the first and second vacuum transfer chambers 160, 160a is not limited to a combination of PVD film formation and CVD film formation. For example, etching may be performed in the wafer processing chamber 110a connected to the second vacuum transfer chamber 160a, which has a higher vacuum level, and then CVD film formation may be performed in the wafer processing chamber 110 connected to the first vacuum transfer chamber 160, which has a lower vacuum level.

[0076] 11 does not show the load lock chamber 130 provided between the first vacuum transfer chamber 160 and the atmospheric transfer chamber 140a. In this regard, the load lock chamber 130 may also be provided with a cleaning area 20 to heat the transfer module 30a, similar to the wafer processing system 101a shown in FIG. 11, the wafer processing chamber 110 may be connected to an atmospheric transfer chamber instead of the first vacuum transfer chamber 160. In this case, a second vacuum transfer chamber 160a is connected to the atmospheric transfer chamber via a load lock chamber 130 in which a cleaning region 20 is provided.

[0077] In the wafer processing systems 101a and 101b according to the examples of FIGS. 9 and 11, the heating unit provided in the cleaning region 20 may be any of the heating light source 411, induction coil 421, coolant supply unit 432 and temperature-control fluid flow path 21 described with reference to FIGS. 5A to 8, or the resistance heating element 313 in the main body 31. A cooling unit (such as the coolant supply unit 432 and temperature-control fluid flow path 21) for the transfer module 30a may be provided on the floor of the load lock chamber 130. Furthermore, an exhaust unit for exhausting the air from the load lock chamber 130 and a contaminant capture member 22 may be provided as a contaminant removal unit. When the contaminant removal unit is configured as an exhaust unit, a vacuum exhaust path for creating a vacuum atmosphere in the load lock chamber 130 can be used.

[0078] 9 and 11, the wafer W may be transferred using the transfer module 30 equipped with the arm unit 32 shown in Fig. 2. In this case, the load lock chamber 130 provided with the cleaning area 20 is configured to be large enough to accommodate the entire transfer module 30 equipped with the arm unit 32.

[0079] 1 and 4 or the load lock chamber 130 shown in Figures 9 and 11. For example, a dedicated processing chamber for heating the transfer modules 30 and 30a may be connected to the rear end of the vacuum transfer chamber 160 via an opening that can be opened and closed by a shutter, and the cleaning region 20 may be set in the processing chamber.

[0080] <Movement control correction> As explained above, in each of the wafer processing systems 101, 101a, and 101b, the transfer modules 30 and 30a are heated using the heating units (heating light source 411, induction coil 421, refrigerant supply unit 432 and temperature-control fluid flow path 21, or resistance heating element 313 in the main body 31), thereby releasing contaminants from the surfaces. On the other hand, it is known that the magnetic force of the module-side magnets 33 provided in the transfer modules 30 and 30a decreases due to thermal demagnetization when heated.

[0081] 12 shows an example in which the movement of the transport modules 30, 30a is controlled using the function of a movement control unit 501 provided in the control unit 5. The movement control unit 501 moves the transport modules 30, 30a to the target position by selecting the moving surface side coil 11 to which power is supplied from the power supply unit 53 and adjusting the amount of power supplied to the moving surface side coil 11.

[0082] At this time, if the magnetic force of the module-side magnets 33 in the transport modules 30, 30a decreases, the repulsive force acting between the moving surface-side coils 11 and the module-side magnets 33 also decreases. As a result, even if the moving surface-side coils 11 are selected in a predetermined order based on a recipe, and a predetermined amount of power is supplied to these moving surface-side coils 11 to perform movement control, there is a risk that the transport modules 30, 30a may not be able to reach the target position.

[0083] 12 includes a position detection unit 52 that identifies the actual positions of the transfer modules 30, 30a within the vacuum transfer chamber 160. Sensors that detect the positions of the transfer modules 30, 30a are provided within the vacuum transfer chamber 160, and the position detection unit 52 identifies the positions of the transfer modules 30, 30a based on information obtained from these sensors.

[0084] Examples of position detection sensors include a plurality of Hall sensors provided at preset positions in the tile 10, a laser displacement meter, and a camera that captures images of the positions of the transfer modules 30 and 30a. Fig. 12 shows an example in which a plurality of Hall sensors 51 are provided on the tile 10.

[0085] The control unit 5 has the function of a deviation amount detection unit 503, and detects the amount of positional deviation between the actual positions of the transport modules 30, 30a detected by the position detection unit 52 and the target position that would be reached if thermal demagnetization of the module-side magnets 33 had not occurred. Since this amount of positional deviation can be said to arise due to thermal demagnetization of the magnetic force of the module-side magnets 33, the control unit 5 uses the function of a correction unit 502 to correct the repulsive force between the moving surface-side coils 11 and the module-side magnets 33, which are controlled using the movement control unit 501, so as to cancel out the amount of positional deviation.

[0086] The correction of the repulsive force by the correction unit 502 can be, for example, a case where linear correction is used. For example, suppose that the result of detecting the levitation height (position in the Z direction shown in FIG. 1) of the transport modules 30, 30a shows that the levitation height has decreased to 80% of the target due to thermal demagnetization. In this case, the correction unit 502 corrects the control value output from the movement control unit 501 so as to increase the power supplied from the power supply unit 53 to the moving surface side coil 11 by 1.25 times. Furthermore, if the influence of the heat source becomes so great that it becomes difficult to reduce the amount of misalignment even after correction, an error may be issued in the wafer processing system 101, 101a to 101c. Upon receiving the error, the transfer module 30, 30a can be removed and the module-side magnet 33 can be magnetized externally to restore the original magnetic force.

[0087] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0088] W wafer 10 tiles 11 Moving surface side coil 101, 101a, 101b Wafer Processing Systems 110, 110a Wafer Processing Chamber 160 Vacuum Transfer Chamber 20 cleaning areas 30, 30a Transfer Module

Claims

[Claim 1] An apparatus for transporting a substrate to a substrate processing chamber in which processing of the substrate is performed, a substrate transfer chamber having a floor portion on which a first magnet is provided and a sidewall portion to which the substrate processing chamber is connected and having an opening formed therein through which substrates are transferred in and out of the substrate processing chamber; a substrate transfer module including a substrate holder that holds the substrate and a second magnet that generates a repulsive force between the second magnet and the first magnet, the substrate transfer module being movable within the substrate transfer chamber by magnetic levitation using the repulsive force; a heating unit that heats the substrate transfer module to release contaminants adhering to a surface of the substrate transfer module.

Images