Patent Publication Number: US-2021180187-A1

Title: Rotational drive device, substrate processing apparatus, and rotational driving method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims priority from Japanese Patent Application No. 2019-223713 filed on Dec. 11, 2019 with the Japan Patent Office, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a rotational drive device, a substrate processing apparatus, and a rotational driving method. 
     BACKGROUND 
     There has been known a film forming apparatus in which a rotary table accommodating a plurality of wafers is rotated to revolve each wafer so that the wafers repeatedly passes through a processing gas supply area which is arranged to follow the radial direction of the rotary table, thereby forming various films on the wafers (see, e.g., Japanese Patent Laid-open Publication No. 2016-092156). In this apparatus, during the revolution of the wafers by the rotary table, a stage for each wafer is rotated to rotate the wafer on its axis, which contributes to the uniformity of the film in the circumferential direction of the wafer. 
     SUMMARY 
     A rotational drive device according to an aspect of the present disclosure includes a first rotator configured to rotate with respect to a stator, a plurality of second rotators configured to rotate with respect to the first rotator, a plurality of second drive units configured to rotatably drive the plurality of second rotators, respectively, and a plurality of drivers configured to rotate integrally with the first rotator and to control rotation of the second drive units, respectively, and each connected to one another by a communication network. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view illustrating a configuration example of a substrate processing apparatus. 
         FIG. 2  is a view illustrating a configuration example of a rotational drive device. 
         FIG. 3  is a view illustrating a configuration example of a driver box. 
         FIG. 4  is a view illustrating another configuration example of a substrate processing apparatus. 
         FIG. 5  is a view illustrating another configuration example of a rotational drive device. 
         FIG. 6  is a flowchart illustrating an example of an operation of the rotational drive device. 
         FIG. 7  is a flowchart illustrating another example of an operation of the rotational drive device. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part thereof. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made without departing from the spirit or scope of the subject matter presented here. 
     Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all of the attached drawings, the same or corresponding members or parts will be designated by the same or corresponding reference numerals, and a duplicate description thereof will be omitted. 
     Substrate Processing Apparatus 
     A configuration example of a substrate processing apparatus will be described with reference to  FIGS. 1 and 2 .  FIG. 1  is a view illustrating a configuration example of a substrate processing apparatus.  FIG. 2  is a view illustrating a configuration example of a rotational drive device. In  FIGS. 1 and 2 , a stator is represented in white, a first rotator which rotates with respect to the stator is represented by dots, and a second rotator which rotates with respect to the first rotator is represented by diagonal lines. Further, in  FIGS. 1 and 2 , a line which transmits electric power is represented by a solid line, a line which transmits a signal is represented by a dashed line, and other lines are illustrated by a one dot chain line. 
     The substrate processing apparatus  1  includes a processor  10 , a rotational drive device  20 , and a control unit  100 . 
     The processor  10  is configured to execute a semiconductor manufacturing process on a substrate. The semiconductor manufacturing process includes, for example, a heat processing, a film forming processing, and an etching processing. The processor  10  includes a vacuum container  11 , a gas introduction port  12 , a gas exhaust port  13 , and a transfer port  14 . 
     The vacuum container  11  is a container capable of decompressing the inside thereof. The vacuum container  11  is configured to be able to accommodate a plurality of substrates therein. However, the vacuum container  11  may be configured to be able to accommodate one substrate therein. The substrate may be, for example, a semiconductor wafer. 
     The gas introduction port  12  is provided in the vacuum container  11 . The gas introduction port  12  may be, for example, a gas nozzle or a shower head. A gas is introduced from a gas supply device  15  into the vacuum container  11  through the gas introduction port  12  to for execute the semiconductor manufacturing process. The gas includes, for example, at least one of a film forming gas, an etching gas, and a purge gas. 
     The gas exhaust port  13  is provided in the vacuum container  11 . The gas exhaust port  13  may be, for example, an opening formed in the wall surface of the vacuum container  11 . The gas introduced into the vacuum container  11  is exhausted by an exhaust device  16  through the gas exhaust port  13 . 
     The transfer port  14  is provided in the vacuum container  11 . The transfer port  14  is an opening for carrying the substrate into the vacuum container  11  or carrying out the substrate from the inside of the vacuum container  11 . The transfer port  14  is opened and closed by a gate valve (not illustrated). 
     The gas supply device  15  introduces the gas for the execution of the semiconductor manufacturing process into the vacuum container  11  through the gas introduction port  12 . The gas supply device  15  includes, for example, a gas supply source, a gas pipe, a valve, and a flow rate controller. 
     The exhaust device  16  exhausts the gas introduced in the vacuum container  11 , and depressurizes the inside of the vacuum container  11 . The exhaust device  16  includes, for example, an exhaust pipe, a valve, and a vacuum pump. 
     The rotational drive device  20  includes a rotary table  21 , a motor box  22 , a rotating shaft  23 , a revolution motor  24 , a driver box  25 , a slip ring  26 , a slip ring  27 , a host controller  28 , and a power supply  29 . 
     The rotary table  21  is provided in the vacuum container  11 . The rotary table  21  is configured to be rotatable around the center of the vacuum container  11  as a rotation axis. The rotary table  21  has, for example, a disk shape. A plurality of stages  211  are provided on the upper surface of the rotary table  21  in the rotation direction (circumferential direction). A substrate is placed on each stage  211 . Each stage  211  configures a second rotator which rotates with respect to the rotary table  21 . 
     The motor box  22  is provided in the vacuum container  11 . The motor box  22  is connected to the rotary table  21  via a connector  212 , and is configured to be rotatable integrally with the rotary table  21 . The inside of the motor box  22  is isolated from the inside of the vacuum container  11 , and is maintained at, for example, an atmospheric pressure. A rotation motor  221 , a sensor  222 , and any other devices  223  are accommodated in the motor box  22 . 
     The rotation motor  221  rotates the substrate by rotating the stage  211  with respect to the rotary table  21  via a rotation shaft  213 . The same number of rotation motors  221  as the stages  211  are provided. The rotation motor  221  may be, for example, a servo motor. The sensor  222  includes, for example, a temperature sensor. The other devices  223  include, for example, an accelerometer. 
     The rotating shaft  23  is fixed to the motor box  22 . However, the rotating shaft  23  may be fixed to the rotary table  21 . The rotating shaft  23  is provided so as to penetrate the bottom of the vacuum container  11 . A magnetic fluid seal  231  is provided to a through-portion of the bottom of the vacuum container  11  to maintain an airtight condition inside the vacuum container  11 . 
     The revolution motor  24  revolves the substrate by rotating the rotary table  21  with respect to the vacuum container  11  via the rotating shaft  23 . Further, when the rotating shaft  23  rotates, the motor box  22  and the driver box  25  rotate integrally with the rotary table  21 . That is, the rotary table  21 , the motor box  22 , the rotating shaft  23 , and the driver box  25  configure a first rotator which rotates integrally. 
     The driver box  25  is fixed to the rotating shaft  23 . Thus, the driver box  25  rotates integrally with the rotating shaft  23 . The driver box  25  is a housing in which a plurality of drivers  251  and a plurality of controllers  252  are accommodated. In addition,  FIG. 1  illustrates only one driver  251  and one controller  252 . 
     The driver  251  is connected to the host controller  28  via the slip ring  26  and a signal line  28   a,  and is connected to the power supply  29  via the slip ring  27  and a power line  29   a.  Further, the driver  251  is connected to the rotation motor  221  via a power cable  251   a  and an encoder cable  251   b . The driver  251  drives the rotation motor  221  so as to follow a command from the host controller  28 . 
     The controller  252  is connected to the host controller  28  via the slip ring  26  and the signal line  28   a,  and is connected to the power supply  29  via the slip ring  27  and the power line  29   a.  Further, the controller  252  is connected to the sensor  222  or the other devices  223  via a cable  252   a,  and controls the sensor  222  or the other devices  223  so as to follow a command from the host controller  28 . The cable  252   a  includes, for example, a power cable and a signal cable. 
     The drivers  251 , the controllers  252 , and the host controller  28  are connected to one another by a communication network (e.g., a wired network). In the present embodiment, the drivers  251 , the controllers  252 , and the host controller  28  are connected to one another by a daisy chain via a field network. The field network may be, for example, EtherCAT (registered trademark). Further, the connection form of the drivers  251  and the controllers  252  may be, for example, a ring form. 
       FIG. 3  is a view illustrating a configuration example of the driver box  25 . The driver box  25  has the shape of a hexagonal column. However, the shape of the driver box  25  is not limited to this, and may be, for example, a cylindrical shape. The driver box  25  includes a top plate  255 , a bottom plate  256 , and six side plates  257 . 
     The top plate  255  has a hexagonal shape, and constitutes the upper bottom surface of the hexagonal column. A through-hole  255   a  and a through-hole  255   b  are formed in the top plate  255 . The through-hole  255   a  is a hole through which the rotating shaft  23  is inserted, and is formed in the center of the top plate  255 . The through-hole  255   b  is a hole through which the power cable  251   a,  the encoder cable  251   b,  or the cable  252   a  is inserted. A plurality of through-holes  255   b  are evenly arranged in the circumferential direction. The number of through-holes  255   b  may be the same as, for example, the number of drivers  251  (the number of rotation motors  221 ). 
     Similarly to the top plate  255 , the bottom plate  256  has a hexagonal shape, and constitutes the lower bottom surface of the hexagonal column. A through-hole (not illustrated) is formed in the bottom plate  256 . The signal line  28   a  or the power line  29   a  is inserted through the through-hole. 
     The side plates  257  have a rectangular shape. The side plates  257  connect the top plate  255  and the bottom plate  256  to each other, and constitute the side surfaces of the hexagonal column. 
     Referring back to  FIG. 2 , the slip ring  26  is provided below the driver box  25 . The slip ring  26  includes a fixed portion  261  and a rotating portion  262 , and is configured to transmit a signal output from the host controller  28  from the fixed portion  261  to the rotating portion  262 , and transmit the signal to the driver  251  and the controller  252  in the driver box  25 . The slip ring  26  may be, for example, a non-contact type slip ring. Thus, the quality of communication is improved, and maintainability is improved. Examples of the non-contact type slip ring may include a slip ring using a capacitive coupling technique. However, the slip ring  26  may be, for example, a contact type slip ring or a rotary connector. 
     The slip ring  27  is provided below the slip ring  26 . The slip ring  27  includes a fixed portion  271  and a rotating portion  272 , and is configured to transmit electric power output from the power supply  29  from the fixed portion  271  to the rotating portion  272 , and transmit the electric power to the driver  251  and the controller  252  in the driver box  25 . The slip ring  27  may be, for example, a non-contact type slip ring. Thus, the quality of communication is improved, and maintainability is improved. Examples of the non-contact type slip ring may include a slip ring using an electromagnetic induction technique. However, the slip ring  27  may be, for example, a contact type slip ring or a rotary connector. 
     The host controller  28  transmits a signal into the driver box  25  via the slip ring  26  and the signal line  28   a.  The signal includes an operation command for the rotation motor  221 , the sensor  222 , and the other devices  223 . The signal transmitted into the driver box  25  is transmitted to the drivers  251  and the controllers  252  connected to one another by the communication network. 
     The power supply  29  transmits electric power to the fixed portion  261  of the slip ring  26 . Further, the power supply  29  transmits electric power to the rotating portion  262  of the slip ring  26  via the slip ring  27 . Further, the power supply  29  transmits electric power into the driver box  25  via the slip ring  27  and the power line  29   a.  The electric power transmitted into the driver box  25  is distributed in the driver box  25  so as to be supplied to each of the drivers  251  and each of the controllers  252 . This distribution of the electric power in the driver box  25  may reduce the number of lines of the slip ring  27 . The power supply  29  may be, for example, a DC24V power supply. 
     The control unit  100  controls each component of the substrate processing apparatus  1 . The control unit  100  may be, for example, a computer. Further, a computer program which takes charge of an operation of each component of the substrate processing apparatus  1  is stored in a storage medium. The storage medium may be, for example, a flexible disk, a compact disk, a hard disk, a flash memory, or a DVD. 
     As described above, the rotational drive device  20  includes the drivers  251  which rotate integrally with the rotary table  21  and control the rotation of the respective rotation motors  221 , and the respective drivers  251  are connected to one another by the communication network. Thus, the number of signal lines  28   a  which transmit a signal between the host controller  28  and the driver box  25  may be reduced to, for example, 1/(the number of drivers  251 ). Therefore, it is possible to suppress a communication failure due to crosstalk caused by the complexity of the signal lines  28   a.  Further, since the number of contacts between the stator and the first rotator is reduced, communication stability is improved. 
     Further, in the rotational drive device  20 , the transmission of a signal between the host controller  28  and the drivers  251  is realized via the non-contact slip ring. Thus, communication stability is ensured, and maintainability is improved. 
     Further, in the rotational drive device  20 , the electric power from the power supply  29  is transmitted into the driver box  25  (rotator) via the non-contact type slip ring, and is distributed in the rotator and supplied to the drivers  251 . Thus, the number of power lines  29   a  which transmit electric power between the power supply  29  and the driver box  25  may be reduced to, for example, 1/(the number of drivers  251 ). Therefore, it is possible to suppress a communication failure due to crosstalk caused by the complexity of the power lines  29   a.  Further, since the number of contacts between the stator and the first rotator is reduced, communication stability is improved. 
     Another configuration example of a substrate processing apparatus will be described with reference to  FIGS. 4 and 5 .  FIG. 4  is a view illustrating another configuration example of a substrate processing apparatus.  FIG. 5  is a view illustrating another configuration example of a rotational drive device. In  FIGS. 4 and 5 , a stator is represented in white, a first rotator which rotates with respect to the stator is represented by dots, and a second rotator which rotates with respect to the first rotator is represented by diagonal lines. Further, in  FIGS. 4 and 5 , a line which transmits electric power is represented by a solid line, a wire which transmits a signal is represented by a dashed line, and other wires are represented by a one dot chain line. 
     As illustrated in  FIG. 4 , the substrate processing apparatus  1 A differs from the substrate processing device  1  described above in that one slip ring  30  transmits a signal and electric power between the stator and the first rotator. In addition, the others of the substrate processing apparatus  1 A are the same as those of the substrate processing apparatus  1  described above and thus, the differences from the substrate processing apparatus  1  will be mainly described below. 
     The substrate processing apparatus  1 A includes the processor  10  and a rotational drive device  20 A. 
     The rotational drive device  20 A includes the rotary table  21 , the motor box  22 , the rotating shaft  23 , the revolution motor  24 , the driver box  25 , the slip ring  30 , the host controller  28 , and the power supply  29 . 
     The slip ring  30  is provided below the driver box  25 . The slip ring  30  includes a fixed portion  301  and a rotating portion  302 , and is configured to transmit a signal output from the host controller  28  and electric power output from the power supply  29  from the fixed portion  301  to the rotating portion  302 , and transmit the signal and the electric power to the driver  251  and the controller  252  in the driver box  25 . The slip ring  30  may be, for example, a non-contact type slip ring. Thus, the quality of communication is improved, and maintainability is improved. However, the slip ring  30  may be, for example, a contact type slip ring or a rotary connector. 
     In the substrate processing apparatus  1 A illustrated in  FIGS. 4 and 5 , since the signal and the electric power may be transmitted from the stator to the first rotator by one slip ring  30 , the simplified structure is achieved, which may significantly reduce the number of signal lines  28   a  and the number of power lines  29   a.    
     Operation of Rotational Drive Device 
     An example of an operation (rotational driving method) of the rotational drive devices  20  and  20 A will be described with reference to  FIG. 6 .  FIG. 6  is a flowchart illustrating an example of an operation of the rotational drive devices  20  and  20 A. 
     In the following, a case where a film by atomic layer deposition (ALD) is formed on a substrate placed on the stage  211  in a state where the control unit  100  controls the rotational drive devices  20  and  20 A to rotate the rotary table  21  and the stage  211  will be described as an example. The rotational driving method illustrated in  FIG. 6  includes steps S 11  to S 13 . 
     In step S 11 , the control unit  100  controls the revolution motor  24  to rotate the rotary table  21 . Thus, substrates on the stages  211  provided in the circumferential direction of the rotary table  21  revolve. The rotation speed of the rotary table  21  may be, for example, 100 to 500 rpm. 
     In step S 12 , the control unit  100  controls the rotation motor  221  to rotate each of the stages  211  provided in the circumferential direction of the rotary table  21  with respect to the rotary table  21 . Thus, the substrate placed on each stage  211  rotates on its axis. The rotation speed of the stage  211  may be, for example, 1 to 30 rpm. 
     In step S 13 , the control unit  100  controls the processor  10  to execute a film forming processing on the substrate. The control unit  100  supplies a raw material gas and a reaction gas to a raw material gas supply area and a reaction gas supply area, respectively, which are arranged in the radial direction of the rotary table  21  on which the substrates are placed. Thus, once the substrate placed on the stage  211  of the rotary table  21  has repeatedly passed through the raw material gas supply area and the reaction gas supply area, a film by ALD is deposited on the surface of the substrate. 
     According to the above rotational driving method, the film by ALD is formed on the surface of the substrate by causing the substrate placed on each stage  211  to repeatedly pass through the raw material gas supply area and the reaction gas supply area while rotating the substrate on its axis. Thus, the uniformity of the film in the circumferential direction of the substrate is improved. 
     Another example of an operation (rotational driving method) of the rotational driving devices  20  and  20 A will be described with reference to  FIG. 7 .  FIG. 7  is a flowchart illustrating another example of an operation of the rotational drive devices  20  and  20 A. 
     In the following, an operation of carrying the substrate placed on the stage  211  of the rotary table  21  out of the vacuum container  11  after rotating the rotary table  21  and the stage  211  as the control unit  100  controls the rotational drive devices  20  and  20 A will be described as an example. The rotational driving method illustrated in FIG.  7  is executed, for example, after the film forming processing is completed on the substrates placed on the stages  211 . The rotational driving method illustrated in  FIG. 7  includes steps S 21  to S 24 . 
     In step S 21 , the control unit  100  controls the revolution motor  24  to rotate the rotary table  21  by a predetermined angle so that one of the stages  211  moves to a position facing the transfer port  14 . 
     In step S 22 , the control unit  100  controls the rotation motor  221  to rotate the stage  211  that has moved to the position facing the transfer port  14  so that the substrate placed on the stage  211  rotates on its axis, thereby implementing the positioning of the substrate in the rotation direction. 
     In step S 23 , the control unit  100  opens the gate valve, and carries out, through the transfer port  14 , the substrate placed on the stage  211  at the position facing the transfer port  14  by a transfer arm from the outside. 
     In step S 24 , the control unit  100  determines whether or not all of the substrates placed on the stages  211  have been completely carried out. When it is determined in step S 24  that all of the substrates have been completely carried out, the control unit  100  ends the processing. Meanwhile, when it is determined in step S 24  that all of the substrates have not been completely carried out, the control unit  100  returns the processing to step S 21 . 
     According to the above rotational driving method, to carry out the substrate for which the film forming processing has been completed, the rotary table  21  is revolved or the stage  211  is rotated, and thereafter, the substrate placed on the stage  211  of the rotary table  21  is carried out of the vacuum container  11 . Thus, the substrate which has been subjected to positioning in the rotation direction may be carried out. 
     In addition, in the above embodiment, the slip rings  26 ,  27 , and  30  are an example of a transmission unit, the revolution motor  24  is an example of a drive unit, and the rotation motor  221  is an example of a second drive unit. 
     In the above embodiment, a case where the rotary table  21  is provided with five stages  211  has been described, but the present disclosure is not limited to this. For example, the number of stages  211  may be four or less, or six or more. 
     In the above embodiment, a case where the processor  10  has the vacuum container  11 , the gas introduction port  12 , the gas exhaust port  13 , and the transfer port  14  has been described, but the present disclosure is not limited to this. For example, the processor  10  may further have a plasma generating unit that generates a plasma for activating various gases supplied into the vacuum container  11 . 
     According to the present disclosure, it is possible to suppress a communication failure caused by lines when a drive unit is disposed on a rotator. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.