TWI884961B - Substrate holding apparatus and substrate processing apparatus - Google Patents

Abstract

The present invention provides a substrate holding device and a substrate processing device, wherein the substrate holding device enables a substrate such as a wafer to perform circular motion and can stably hold the substrate while rotating the substrate around its axis. The substrate holding device (10) comprises: a plurality of rollers (11a, 11b); a plurality of motors (29a, 29b) for rotating the plurality of rollers (11a, 11b); a plurality of eccentric shafts (13a, 13b) arranged around a central axis (CP); and a plurality of actuators (18). A plurality of eccentric shafts (13a, 13b) are composed of a plurality of movable shafts (13b) and a plurality of reference shafts (13a), a plurality of actuators (18) are respectively connected to the plurality of movable shafts (13b), and the plurality of actuators (18) are configured to move the plurality of movable shafts (13b) in a direction approaching the plurality of reference shafts (13a) and in a direction away from the plurality of reference shafts (13a).

Description

Substrate holding device and substrate processing device

The present invention relates to a substrate holding device that holds a substrate such as a wafer and rotates it. In addition, the present invention relates to a substrate processing device having such a substrate holding device.

In recent years, devices such as memory circuits, logic circuits, and image sensors (such as CMOS sensors) are being more integrated. In the process of forming these devices, foreign matter such as particles and dust sometimes adheres to the devices. Foreign matter attached to the devices can cause short circuits between wiring and circuit failures. Therefore, in order to improve the reliability of the devices, it is necessary to clean the wafers on which the devices are formed to remove foreign matter on the wafers.

Foreign objects such as microparticles and dust as mentioned above are sometimes attached to the back side of the wafer (bare silicon surface). When such foreign objects are attached to the back side of the wafer, the wafer will leave the stage reference plane of the exposure device, or the wafer surface will tilt relative to the stage reference plane, resulting in patterned offset and focus distance offset. In order to prevent such problems, it is necessary to remove foreign objects attached to the back side of the wafer.

Patent document 1: Japanese Patent Publication No. 2019-83224

Problem that the invention is intended to solve

Recently, there is an increasing demand for a device that can process the entire surface of a substrate more efficiently. Therefore, a substrate holding device has been proposed, which holds the periphery of the substrate by a plurality of rollers connected to a plurality of eccentric shafts, and rotates each eccentric shaft around its axis while the eccentric shaft itself is stationary, thereby causing the substrate to perform a circular motion while rotating around its axis (e.g., Patent Document 1).

In a substrate processing device using such a substrate holding device, the roller does not contact the processing tool, and the processing tool can process the entire surface of the substrate including the outermost surface. In addition, the combination of such circular motion and rotation centered on the axis of the substrate can increase the speed of each point on the substrate surface, resulting in improved substrate processing efficiency.

In such a substrate holding device, the phases of multiple eccentric shafts need to be aligned with each other. However, it is difficult to correctly align the phases of multiple eccentric shafts, and during the rotation of the substrate, vibrations are sometimes generated in the eccentric shafts due to phase shift. When one of the multiple eccentric shafts vibrates, the vibration is sometimes transmitted to other eccentric shafts via the common support plate supporting these eccentric shafts, so that the holding of the substrate becomes unstable.

Therefore, the purpose of the present invention is to provide a substrate holding device that allows a substrate such as a wafer to perform circular motion and can stably hold the substrate while rotating the substrate about its axis. In addition, the purpose of the present invention is to provide a substrate processing device that is used to process the surface of a substrate using such a substrate holding device.

In one embodiment, a substrate holding device causes a substrate to perform circular motion while causing the substrate to rotate about an axis of the substrate, and the substrate holding device comprises: a plurality of rollers capable of contacting a peripheral portion of the substrate; a plurality of motors for rotating the plurality of rollers; a plurality of eccentric shafts arranged around a predetermined central axis; and a plurality of actuators, wherein the plurality of eccentric shafts have a plurality of first shaft portions and a plurality of second shaft portions. The plurality of second shafts are eccentric from the plurality of first shafts, the plurality of rollers are fixed to the plurality of second shafts, the plurality of first shafts are connected to the plurality of motors, the plurality of eccentric shafts are composed of a plurality of movable shafts and a plurality of reference shafts, the plurality of actuators are connected to the plurality of movable shafts, and the plurality of actuators are configured to move the plurality of movable shafts in directions approaching the plurality of reference shafts and in directions away from the plurality of reference shafts.

In one embodiment, the plurality of eccentric shafts also have a plurality of intermediate shaft portions, which connect the plurality of first shaft portions with the plurality of second shaft portions, the plurality of first shaft portions are respectively fixed to the plurality of intermediate shaft portions, and the plurality of second shaft portions are respectively fixed to the plurality of intermediate shaft portions.

In one embodiment, the substrate holding device further includes a motion control unit that causes the plurality of motors to rotate at the same speed and in the same phase.

In one embodiment, the directions approaching the plurality of reference axes and the directions departing from the plurality of reference axes are the directions toward the center axis and the directions departing from the center axis.

In one embodiment, the plurality of actuators respectively include: a piston; a housing, which is disposed away from the piston; and a partition membrane, which forms a pressure chamber between the piston and the housing.

In one embodiment, the partition membrane has: a central portion, which contacts the end of the piston; an inner wall portion, which is connected to the central portion and extends along the side of the piston; a folded portion, which is connected to the inner wall portion and has a curved cross section; and an outer wall portion, which is connected to the folded portion and is located on the outer side of the inner wall portion.

In one embodiment, the substrate holding device further includes at least one non-contact distance sensor, which measures the moving distance of at least one movable shaft among the plurality of movable shafts.

In one embodiment, the substrate holding device further includes an action control unit, which is configured to determine whether an abnormality occurs in the substrate holding device by comparing the measured value of the moving distance or an index value calculated based on a plurality of measured values of the moving distance with a preset threshold value.

In one embodiment, the index value is the average value of the position of at least one movable shaft among the plurality of movable shafts when the plurality of rollers rotate one or more circles.

In one embodiment, the index value is the difference between the maximum value and the minimum value of the position of at least one of the plurality of movable shafts during one or more rotations of the plurality of rollers.

In one embodiment, a substrate holding device causes a substrate to perform circular motion while causing the substrate to rotate about an axis of the substrate, and the substrate holding device comprises: a plurality of rollers capable of contacting a peripheral portion of the substrate; a plurality of motors for rotating the plurality of rollers; a plurality of eccentric shafts arranged around a predetermined central axis; and an actuator, wherein the plurality of eccentric shafts have a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentrically disposed from the plurality of first shaft portions, and the plurality of second shaft portions being eccentrically disposed from the plurality of first shaft portions, and the plurality of second shaft portions being eccentrically disposed from the plurality of first shaft portions, and the plurality of second shaft portions being eccentrically disposed from the plurality of first shaft portions, and the plurality of second shaft portions being eccentrically disposed from the plurality of first shaft portions, and the plurality of The plurality of rollers are respectively fixed to the plurality of second shafts, the plurality of first shafts are respectively connected to the plurality of motors, the plurality of eccentric shafts are composed of a movable shaft and a plurality of reference shafts, the actuator is connected to the movable shaft, the actuator is configured to move the movable shaft in a direction approaching the plurality of reference shafts and in a direction away from the plurality of reference shafts, and the actuator has a piston; a housing, the housing is separated from the piston; and a partition membrane, the partition membrane forms a pressure chamber between the piston and the housing.

In one embodiment, the plurality of eccentric shafts further have a plurality of intermediate shaft portions, which connect the plurality of first shaft portions with the plurality of second shaft portions, the plurality of first shaft portions are respectively fixed to the plurality of intermediate shaft portions, and the plurality of second shaft portions are respectively fixed to the plurality of intermediate shaft portions.

In one embodiment, the substrate holding device further includes a motion control unit that causes the plurality of motors to rotate at the same speed and in the same phase.

In one embodiment, the directions approaching the plurality of reference axes and the directions departing from the plurality of reference axes are the directions toward the center axis and the directions departing from the center axis.

In one embodiment, the partition membrane has: a central portion that contacts the end of the piston; an inner wall portion that is connected to the central portion and extends along the side of the piston; a folded portion that is connected to the inner wall portion and has a curved cross section; and an outer wall portion that is connected to the folded portion and is located outside the inner wall portion.

In one embodiment, the substrate holding device further includes a non-contact distance sensor that measures the moving distance of the movable shaft.

In one embodiment, the substrate holding device further includes an action control unit, which is configured to determine whether an abnormality occurs in the substrate holding device by comparing the measured value of the moving distance or an index value calculated based on a plurality of measured values of the moving distance with a preset threshold value.

In one embodiment, the index value is the average value of the position of the movable shaft when the plurality of rollers rotate more than one circle.

In one embodiment, the index value is the difference between the maximum and minimum values of the position of the movable shaft during one or more rotations of the plurality of rollers.

In one embodiment, a substrate processing device is provided, comprising: the substrate holding device; and a processing head, the processing head brings a processing tool into contact with a first surface of a substrate to process the first surface.

According to the present invention, a plurality of movable shafts are connected to a plurality of actuators respectively, and are not supported by a common support plate. According to such a structure, even if one movable shaft vibrates during the rotation of the substrate, the vibration can be prevented from being transmitted to other movable shafts. As a result, the substrate holding device can stably hold the substrate.

Furthermore, according to the present invention, since the housing of the actuator is separated from the piston configuration, no sliding resistance is generated between the piston and the housing. As a result, the substrate holding device can stably hold the substrate without applying an excessive load to the substrate.

1: First page

2: Second side

10: Substrate holding device

11a, 11b: Roller

13a: Eccentric shaft, reference shaft

13b: Eccentric shaft, movable shaft

14a, 14b: first axis

15a, 15b: Second axis

16a, 16b: middle shaft

17a, 17b: Counterweight

18: Actuator

19: Bearings

20: Base plate

21: Movable table

23: Connecting parts

24: Bearings

26: Linear guide parts

27a, 27b: Motor support body

28a, 28b: coupling

29a, 29b: Electric motor

31a, 31b: Wafer holding surface (substrate holding surface)

40: Motion control unit

40a: Storage device

40b: Computing device

51: Piston

52a, 52b: Shell

53a, 53b: Shell body

54a, 54b: Cover

55a, 55b: septum membrane

57a, 57b: Pressure chamber

59a, 59b: Compressed gas flow path

62a, 62b: Pressure regulator

63a, 63b: Switching valve

64: Compressed gas supply source

71a, 71b: Central part

72a, 72b: Inner wall

73a, 73b: Return section

74a, 74b: Outer wall

75a, 75b: Thick wall part

80: Distance sensor

81: Magnet

84:Sensor head

85: Focusing lens

88:Sensor target

92A: Projection optical cable

92B: Light receiving cable

93:Amplifier

93a: Light source

93b: Light intensity meter

94: Distance calculator

100: Substrate processing device

200: Processing head

201: Processing tools

CP: Center axis of substrate holding device

e: Eccentric distance of the first axis

W: Wafer

FIG1 is a top view schematically showing an embodiment of a substrate holding device.

FIG2 is a side view of the substrate holding device shown in FIG1.

FIG3 is a bottom view of the substrate holding device shown in FIG1.

Figure 4 (a) to Figure 4 (d) are schematic diagrams illustrating the action of the substrate holding device receiving the wafer.

FIG5 is a schematic diagram showing an implementation of an actuator.

FIG6 is a cross-sectional view schematically showing an implementation of a partition membrane.

FIG7(a) is a diagram showing the state of the actuator when the pressure in the first pressure chamber is higher than the pressure in the second pressure chamber, and FIG7(b) is a diagram showing the state of the actuator when the pressure in the second pressure chamber is higher than the pressure in the first pressure chamber.

FIG8 is a diagram showing an example of the position of the movable axis when a rotational abnormality of the wafer occurs.

FIG. 9 is a diagram showing another example of the position of the movable axis when a rotational abnormality of the wafer occurs.

FIG10 is a schematic diagram showing another implementation of the distance sensor.

FIG. 11 is a top view schematically showing an embodiment of a substrate processing device having a substrate holding device described with reference to FIGS. 1 to 10 .

FIG12 is a side view of the substrate holding device shown in FIG11.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a top view schematically showing an embodiment of a substrate holding device, FIG. 2 is a side view of the substrate holding device shown in FIG. 1 , and FIG. 3 is a bottom view of the substrate holding device shown in FIG. The substrate holding device of this embodiment is configured to hold a wafer W as an example of a substrate while causing the wafer W to perform a circular motion and rotate the wafer W around its axis. The substrate holding device 10 includes: a plurality of rollers 11a, 11b capable of contacting the periphery of the wafer W; a plurality of motors 29a, 29b for rotating the plurality of rollers 11a, 11b; a plurality of eccentric shafts 13a, 13b connecting the plurality of rollers 11a, 11b and the plurality of motors 29a, 29b; and an action control unit 40 for rotating the plurality of motors 29a, 29b at the same speed and in the same phase.

The motion control unit 40 is composed of at least one computer. The motion control unit 40 has a storage device 40a and a computing device 40b. The computing device 40b includes a CPU (central processing unit) or a GPU (graphics processing unit), etc. The CPU performs operations according to the commands contained in the program stored in the storage device 40a. The storage device 40a has a main storage device (such as a random access memory) that can be accessed by the computing device 40b and an auxiliary storage device (such as a hard disk drive or a solid-state drive) for storing data and programs.

Roller 11a has a wafer holding surface (substrate holding surface) 31a for holding the peripheral portion of wafer W, and roller 11b has a wafer holding surface (substrate holding surface) 31b for holding the peripheral portion of wafer W. Roller 11a and roller 11b have the same structure and the same size. Multiple eccentric shafts 13a, 13b are arranged around a predetermined center axis CP of the substrate holding device 10.

The substrate holding device 10 of this embodiment has two rollers 11a, two rollers 11b, two eccentric shafts 13a, two eccentric shafts 13b, two motors 29a and two motors 29b, but the number of these components is not limited by this embodiment.

The plurality of eccentric shafts 13a each include a first shaft portion 14a, a second shaft portion 15a eccentric from the first shaft portion 14a, and an intermediate shaft portion 16a connecting the first shaft portion 14a and the second shaft portion 15a. At least two of the first shaft portion 14a, the second shaft portion 15a, and the intermediate shaft portion 16a may be an integral structure. For example, the first shaft portion 14a and the intermediate shaft portion 16a may be an integral structure. In other examples, the entirety of the first shaft portion 14a, the second shaft portion 15a, and the intermediate shaft portion 16a may be an integral structure. Each eccentric shaft 13a shown in FIG2 has a crankshaft shape, but the shape of each eccentric shaft 13a is not limited to this embodiment as long as the second shaft portion 15a is eccentric to a predetermined distance from the first shaft portion 14a.

The plurality of rollers 11a are fixed to one end of the plurality of second shafts 15a, and the other ends of the plurality of second shafts 15a are fixed to the plurality of intermediate shafts 16a. One end of the plurality of first shafts 14a is connected to the plurality of motors 29a via the plurality of couplings 28a, and the other ends of the plurality of first shafts 14a are fixed to the plurality of intermediate shafts 16a.

The plurality of eccentric shafts 13b respectively include a first shaft portion 14b, a second shaft portion 15b eccentric from the first shaft portion 14b, and an intermediate shaft portion 16b connecting the first shaft portion 14b and the second shaft portion 15b. At least two of the first shaft portion 14b, the second shaft portion 15b, and the intermediate shaft portion 16b may be an integral structure. For example, the first shaft portion 14b and the intermediate shaft portion 16b may be an integral structure. In other examples, the entirety of the first shaft portion 14b, the second shaft portion 15b, and the intermediate shaft portion 16b may be an integral structure. Each eccentric shaft 13b shown in FIG2 has a crankshaft shape, but the shape of each eccentric shaft 13b is not limited to this embodiment as long as the second shaft portion 15b is eccentric to a predetermined distance from the first shaft portion 14b.

The plurality of rollers 11b are fixed to one end of the plurality of second shafts 15b, and the other ends of the plurality of second shafts 15b are fixed to the plurality of intermediate shafts 16b. One end of the plurality of first shafts 14b is connected to the plurality of motors 29b via the plurality of couplings 28b, and the other ends of the plurality of first shafts 14b are fixed to the plurality of intermediate shafts 16b.

The motor 29a rotates the eccentric shaft 13a around its first shaft portion 14a, and the motor 29b rotates the eccentric shaft 13b around its first shaft portion 14b. The motors 29a and 29b are connected to the motion control unit 40.

The second shaft 15a of the eccentric shaft 13a is eccentric from the first shaft 14a by a distance e. Therefore, when the motor 29a is working, the roller 11a rotates around the second shaft 15a and performs a circular motion with a radius of e. The axis of the roller 11a coincides with the axis of the second shaft 15a. That is, the roller 11a rotates around its axis and performs a circular motion with a radius of e around the axis of the first shaft 14a. When the roller 11a rotates one circle around the axis of the first shaft 14a, the roller 11a rotates one circle around the axis of the roller 11a.

Similarly, the second shaft 15b of the eccentric shaft 13b is eccentric from the first shaft 14b by a distance e. Therefore, when the motor 29b is operated, the roller 11b rotates around the second shaft 15b and performs a circular motion with a radius of e. The axis of the roller 11b coincides with the axis of the second shaft 15b. That is, the roller 11b rotates around its axis and performs a circular motion with a radius of e around the axis of the first shaft 14b. When the roller 11b rotates one circle around the axis of the first shaft 14b, the roller 11b rotates one circle around the axis of the roller 11b. In this manual, circular motion is defined as the motion of an object moving on a circular orbit.

The motion of the motors 29a and 29b is controlled by the motion control unit 40. As described above, the motion control unit 40 causes all the motors 29a and 29b to rotate at the same speed and in the same phase. More specifically, the motion control unit 40 issues instructions to the motors 29a and 29b so that all the motors 29a and 29b start at the same time and rotate in the same direction. Furthermore, the motion control unit 40 synchronizes the rotation speed and phase of each motor 29a and 29b during the motion.

As a result, all eccentric shafts 13a and 13b rotate in the same direction at the same rotation speed and the same phase with the axis of the first shaft 14a and 14b as the center. All rollers 11a and 11b rotate in the same direction at the same rotation speed and the same phase with their axis as the center, while performing circular motion with the axis of the first shaft 14a and 14b as the center. Therefore, when the wafer W is held by the rollers 11a and 11b, the motors 29a and 29b are operated by the motion control unit 40, and the wafer W rotates with its axis as the center while performing circular motion with a radius of e.

In this way, the substrate holding device 10 can make the wafer W perform circular motion while rotating the wafer W around its axis with a simple structure. The combination of such circular motion and rotation around the axis of the wafer W can increase the speed of each point on the surface of the wafer W. Therefore, when the processing head is pressed against the surface of the wafer W described later, the relative speed between the processing head and the surface of the wafer W increases, thereby increasing the processing speed of the wafer W.

Counterweights 17a and 17b are fixed to the multiple eccentric shafts 13a and 13b, respectively. More specifically, the counterweights 17a and 17b are fixed to the intermediate shafts 16a and 16b, respectively. The counterweight 17a and the roller 11a are arranged symmetrically with respect to the first shaft 14a. The weight of the counterweight 17a is the weight that is offset by the centrifugal force acting on the counterweight 17a when the eccentric shaft 13a rotates around the first shaft 14a.

Similarly, the counterweight 17b and the roller 11b are arranged symmetrically with respect to the first shaft 14b. The weight of the counterweight 17b is such that when the eccentric shaft 13b rotates around the first shaft 14b, the centrifugal force generated in the radial direction from the first shaft 14b toward the roller 11b is offset by the centrifugal force acting on the counterweight 17b. When the eccentric shafts 13a and 13b rotate, such counterweights 17a and 17b can prevent the vibration of the eccentric shafts 13a and 13b caused by the imbalance of weight.

The substrate holding device 10 also includes: a base plate 20; a plurality of linear guides 26 fixed to the lower surface of the base plate 20; a plurality of movable tables 21 supported by the plurality of linear guides 26; and a plurality of actuators 18 connected to the plurality of movable tables 21. The linear guides 26 limit the movement of the movable table 21 to a linear movement in a direction parallel to the lower surface of the base plate 20.

Each movable table 21 has a bearing 24 that supports the eccentric shaft 13b so that it can rotate and a connecting member 23 that is connected to the actuator 18. The plurality of actuators 18 are connected to the plurality of eccentric shafts 13b through the plurality of movable tables 21. The plurality of movable tables 21, each including the plurality of bearings 24, are integrated with the plurality of eccentric shafts 13b and move independently through the plurality of actuators 18.

The actuator 18 is fixed to the lower surface of the base plate 20. The movement of the actuator 18 is controlled by the movement control unit 40. The movement control unit 40 can make the actuators 18 move independently. The actuator 18 is configured to move the movable table 21 parallel to the base plate 20.

The eccentric shaft 13a extends through the bottom plate 20. The roller 11a is arranged above the bottom plate 20, and the motor 29a is arranged below the bottom plate 20. The eccentric shaft 13a is supported by the bearing 19 held by the bottom plate 20 so as to be rotatable. The positions of these eccentric shafts 13a are fixed. The motor 29a is fixed to the bottom plate 20 via the motor support body 27a. More specifically, the motor support body 27a is fixed to the lower surface of the bottom plate 20, and the motor 29a is fixed to the motor support body 27a.

The eccentric shaft 13b extends through the movable table 21 and the bottom plate 20. The roller 11b is arranged above the bottom plate 20, and the motor 29b is arranged below the bottom plate 20. The eccentric shaft 13b is supported by the bearing 24 of the movable table 21 so as to be rotatable. The motor 29b is fixed to the movable table 21 via the motor support body 27b. More specifically, the motor support body 27b is fixed to the lower surface of the movable table 21, and the motor 29b is fixed to the motor support body 27b.

According to the above structure, the eccentric shaft 13a is a reference shaft that is immovable relative to the base plate 20, and the eccentric shaft 13b is a movable shaft that is movable relative to the base plate 20. In the following description, the eccentric shaft 13a is sometimes referred to as the reference shaft 13a, and the eccentric shaft 13b is sometimes referred to as the movable shaft 13b. The actuator 18 is connected to the movable shaft 13b via the movable table 21. The movable table 21 has a bearing 24 that supports the movable shaft 13b to be rotatable and a connecting member 23 connected to the actuator 18. Therefore, the movable table 21 connects the actuator 18 and the movable shaft 13b.

The actuator 18 can move the movable shaft 13b in parallel with the base plate 20 via the movable table 21. Specifically, the plurality of actuators 18 are configured to move the plurality of movable shafts 13b in a direction approaching the plurality of reference shafts 13a and in a direction away from the plurality of reference shafts 13a. When the two movable shafts 13b move in a direction approaching the two reference shafts 13a, the wafer W is held by the two rollers 11a and the two rollers 11b. When the two movable shafts 13b move in a direction away from the two reference shafts 13a, the wafer W is released from the two rollers 11a and the two rollers 11b.

As shown in FIG3 , in the present embodiment, the actuator 18 and the linear guide 26 are arranged toward the center axis CP of the substrate holding device 10. The actuator 18 moves the movable shaft 13b in the direction of the arrow in FIG3 . In the present embodiment, the direction approaching the plurality of reference axes 13a and the direction moving away from the plurality of reference axes 13a are the direction toward the center axis CP and the direction moving away from the center axis CP. When the movable shaft 13b is moved toward the direction toward the center axis CP, the roller 11b can hold the wafer W with a gripping force toward the center of the wafer W. According to the structure of the present embodiment, the substrate holding device 10 can efficiently hold the wafer W with a minimum force. In one embodiment, the plurality of actuators 18 and the plurality of linear guides 26 may also be arranged toward each of the plurality of reference axes 13a.

Figures 4 (a) to 4 (d) are schematic diagrams illustrating the action of the substrate holding device 10 receiving the wafer W. As shown in Figure 4 (a), before receiving the wafer W, each actuator 18 (refer to Figures 2 and 3) is operated to move each roller 11b away from the central axis CP. At this time, the rollers 11a and 11b are eccentric to the outside.

Next, as shown in FIG4(b), the wafer W is transported to the substrate holding device 10 by a transport device (not shown). Furthermore, as shown in FIG4(c), when the wafer W is located between the rollers 11a and 11b, the reference axis 13a is rotated 180 degrees, so that each roller 11a is eccentric inward. Then, as shown in FIG4(d), each actuator 18 is operated, so that each roller 11b and each movable axis 13b are moved in a direction close to each reference axis 13a until each roller 11b contacts the wafer W.

In this way, the periphery of the wafer W is held by the wafer holding surface 31a of the roller 11a and the wafer holding surface 31b of the roller 11b. When the wafer W is taken out from the substrate holding device 10, the steps shown in FIG. 4 (a) to FIG. 4 (d) are performed in the reverse order.

In the existing substrate holding device (for example, refer to Patent Document 1), a plurality of movable shafts are supported by a support plate, and an actuator connected to the support plate moves the plurality of movable shafts and the support plate integrally to hold the substrate. According to such a structure, when one of the plurality of movable shafts vibrates due to phase deviation between the plurality of eccentric shafts, the vibration is transmitted to the other movable shafts, and the holding of the substrate becomes unstable.

In contrast, in the above-mentioned embodiment, the two movable shafts 13b are supported by two movable tables 21, respectively, and are further connected to two actuators 18, respectively. According to such a structure, during the rotation of the wafer W, even if one movable shaft 13b vibrates, the vibration can be prevented from being propagated to the other movable shafts 13b. As a result, the substrate holding device 10 can stably hold the wafer W.

FIG5 is a schematic diagram showing an implementation of the actuator 18. Each actuator 18 includes: a piston 51 arranged in the longitudinal direction of the actuator 18; housings 52a, 52b arranged on the outer side of the piston 51; and partition membranes (diaphragms) 55a, 55b forming pressure chambers 57a, 57b between the piston 51 and the housings 52a, 52b. The piston 51 can move in the direction indicated by the arrow in FIG5 (the longitudinal direction of the actuator 18). The housings 52a, 52b are arranged away from the piston 51. The housing 52a is arranged in a manner surrounding one end of the piston 51, and the housing 52b is arranged in a manner surrounding the other end of the piston 51.

The piston 51 is connected to the connecting member 23 of the movable table 21, and the piston 51 is supported by the connecting member 23. The movable table 21 including the connecting member 23 can move in the direction indicated by the arrow in FIG. 5 together with the piston 51. More specifically, the movable table 21 is configured to be able to move in the direction approaching the reference axis 13a and in the direction away from the reference axis 13a together with the piston 51. In this embodiment, the actuator 18 is arranged toward the center axis CP of the substrate holding device 10 (refer to FIG. 3), so the movement direction of the piston 51 and the movable table 21 is the direction toward the center axis CP and the direction away from the center axis CP.

The housing 52a, 52b has housing bodies 53a, 53b arranged to surround the side surface of the piston 51 and covers 54a, 54b fixed to the housing bodies 53a, 53b. The edge of the partition membrane 55a is sandwiched between the housing body 53a and the cover 54a. Similarly, the edge of the partition membrane 55b is sandwiched between the housing body 53b and the cover 54b.

The pressure chamber 57a is formed by the partition membrane 55a and the inner surface of the housing 52a. Similarly, the pressure chamber 57b is formed by the partition membrane 55b and the inner surface of the housing 52b. More specifically, the pressure chamber 57a is formed by the partition membrane 55a and the inner surface of the cover 54a, and the pressure chamber 57b is formed by the partition membrane 55b and the inner surface of the cover 54b. The partition membranes 55a and 55b have the same structure. In this embodiment, the housings 52a and 52b have the same structure, but may have different structures.

Compressed gas flow paths 59a and 59b are formed on the covers 54a and 54b of the shells 52a and 52b. The compressed gas flow paths 59a and 59b are connected to the compressed gas supply source 64 via the pressure regulators 62a and 62b and the switching valves 63a and 63b. The pressure chambers 57a and 57b are connected to the pressure regulators 62a and 62b via the compressed gas flow paths 59a and 59b.

When the piston 51 is moved, the switching valves 63a and 63b are operated to connect the pressure chambers 57a and 57b to the compressed gas supply source 64. In the present embodiment, the switching valves 63a and 63b are connected to the motion control unit 40. The switching valves 63a and 63b are valves that selectively connect the pressure chambers 57a and 57b to the compressed gas supply source 64 or the atmosphere. As the switching valves 63a and 63b, three-way valves can be used.

Compressed gas such as compressed air is supplied to the pressure chambers 57a and 57b from the compressed gas supply source 64 through the compressed gas flow paths 59a and 59b. As an example of the compressed gas supply source 64, a pump or a compressed gas supply pipeline pre-installed in a factory as a public facility can be cited. The pressure of the compressed gas in the pressure chambers 57a and 57b is controlled by the pressure regulators 62a and 62b. In the present embodiment, the pressure regulators 62a and 62b are electrically controlled pneumatic pressure regulators. The pressure regulators 62a and 62b of the present embodiment are connected to the action control unit 40. In one embodiment, the pressure regulators 62a, 62b may also be manually operated pressure regulators. In this case, the pressure regulators 62a, 62b are not connected to the motion control unit 40.

The action control unit 40 sends a specified set pressure value to the pressure regulators 62a and 62b, and the pressure regulators 62a and 62b control the pressure of the compressed gas in the pressure chambers 57a and 57b according to the set pressure value. As examples of such pressure regulators 62a and 62b, an electrically controlled air pressure regulator or a mechanical air pressure regulator can be cited. In one embodiment, the pressure regulator 62b can also be set as an electrically controlled air pressure regulator, and the pressure regulator 62a can be set as a mechanical air pressure regulator. When the pressure regulator 62a is set as a mechanical air pressure regulator, the pressure regulator 62a is not connected to the action control unit 40.

The piston 51 moves according to the difference between the pressure in the pressure chamber 57a and the pressure in the pressure chamber 57b. When the pressure in the pressure chamber 57a is higher than the pressure in the pressure chamber 57b, the piston 51 moves in a direction away from the reference axis 13a (see Figure 3). When the pressure in the pressure chamber 57b is higher than the pressure in the pressure chamber 57a, the piston 51 moves in a direction close to the reference axis 13a (see Figure 3).

In this embodiment, when the piston 51 is moved, compressed gas is introduced into both the pressure chambers 57a and 57b, and the pressure of the compressed gas inside one of the pressure chambers 57a and 57b is higher than the pressure of the compressed gas inside the other. In one embodiment, when the piston 51 is moved, compressed gas may be introduced into only one of the pressure chambers 57a and 57b, and the other may be connected to the atmosphere.

FIG6 is a cross-sectional view schematically showing an embodiment of the partition membrane 55a, 55b. The partition membrane 55a has: a central portion 71a, which contacts one end of the piston 51; an inner wall portion 72a, which is connected to the central portion 71a and extends along the side of the piston 51; a folded portion 73a, which is connected to the inner wall portion 72a and has a curved cross section; and an outer wall portion 74a, which is connected to the folded portion 73a and is located on the outer side of the inner wall portion 72a. The partition membrane 55a contacts one end of the piston 51. When the compressed gas is introduced into the pressure chamber 57a, the outer wall portion 74a contacts the inner surface of the shell body 53a.

In this embodiment, the central portion 71a is circular. The inner wall portion 72a and the outer wall portion 74a have a cylindrical shape, and the inner wall portion 72a contacts the side surface of the piston 51. The outer wall portion 74a is configured to surround the inner wall portion 72a.

Similarly, the partition membrane 55b has: a central portion 71b, which contacts the other end of the piston 51; an inner wall portion 72b, which is connected to the central portion 71b and extends along the side of the piston 51; a return portion 73b, which is connected to the inner wall portion 72b and has a curved cross-section; and an outer wall portion 74b, which is connected to the return portion 73b and is located on the outer side of the inner wall portion 72b. The partition membrane 55b contacts the other end of the piston 51. When the compressed gas is introduced into the pressure chamber 57b, the outer wall portion 74b contacts the inner surface of the shell body 53b.

In this embodiment, the central portion 71b is circular. The inner wall portion 72b and the outer wall portion 74b have a cylindrical shape, and the inner wall portion 72b contacts the side surface of the piston 51. The outer wall portion 74b is configured to surround the inner wall portion 72b.

The partition membranes 55a and 55b are in contact with the piston 51, but are not fixed to the piston 51. The thick wall portion 75a constituting the edge of the partition membrane 55a is sandwiched between the shell body 53a and the cover 54a. Similarly, the thick wall portion 75b constituting the edge of the partition membrane 55b is sandwiched between the shell body 53b and the cover 54b. The partition membranes 55a and 55b are formed of a soft material. Examples of materials constituting the partition membranes 55a and 55b include neoprene, fluororubber, and silicone rubber. It is preferable to use neoprene with high bending fatigue resistance.

FIG. 7 (a) is a diagram showing the state of the actuator 18 when the pressure in the pressure chamber 57a (first pressure chamber 57a) is higher than the pressure in the pressure chamber 57b (second pressure chamber 57b), and FIG. 7 (b) is a diagram showing the state of the actuator 18 when the pressure in the pressure chamber 57b is higher than the pressure in the pressure chamber 57a.

As shown in (a) of FIG. 7 , when the pressure in the pressure chamber 57a is higher than the pressure in the pressure chamber 57b, a force in the direction of the pressure chamber 57b is applied to the piston 51. As a result, the partition membranes 55a and 55b are deformed, and the piston 51, the movable table 21, and the movable shaft 13b move integrally in a direction away from the reference shaft 13a (see FIG. 3 ). At this time, while the folding portion 73a maintains its shape, a part of the inner wall portion 72a becomes a part of the folding portion 73a, and a part of the folding portion 73a becomes a part of the outer wall portion 74a. At the same time, the folding portion 73b maintains its shape, and a part of the outer wall portion 74b becomes a part of the folding portion 73b, and a part of the folding portion 73b becomes a part of the inner wall portion 72b.

As shown in (b) of FIG. 7 , when the pressure in the pressure chamber 57b is higher than the pressure in the pressure chamber 57a, a force in the direction of the pressure chamber 57a is applied to the piston 51. As a result, the partition film 55b is deformed, and the piston 51, the movable table 21, and the movable shaft 13b move in a direction close to the reference shaft 13a (see FIG. 3 ). At this time, the folding portion 73b maintains its shape, and a part of the inner wall portion 72b becomes a part of the folding portion 73b, and a part of the folding portion 73b becomes a part of the outer wall portion 74b. At the same time, the folding portion 73a maintains its shape, and a part of the outer wall portion 74a becomes a part of the folding portion 73a, and a part of the folding portion 73a becomes a part of the inner wall portion 72a.

Through the action of the partition films 55a and 55b, the piston 51 can move smoothly with almost no reaction force from the partition films 55a and 55b. When the piston is in contact with the housing as in a conventional cylinder, when vibration occurs during the rotation of the wafer, sliding resistance is generated between the piston and the housing. Such sliding resistance applies an excessive load to the rotating wafer, which becomes the main reason for the unstable holding of the wafer. In this embodiment, since the housings 52a and 52b are arranged away from the piston 51, no sliding resistance is generated between the piston 51 and the housings 52a and 52b. As a result, the substrate holding device 10 can stably hold the wafer W without applying an excessive load to the wafer W.

As shown in FIG5 , the substrate holding device 10 has a non-contact distance sensor 80 for measuring the moving distance of the movable shaft 13b. The distance sensor 80 is arranged on the outer side of the actuator 18 and near the actuator 18 and the movable table 21. A magnet 81 is fixed to the connecting member 23 of the movable table 21, and the distance sensor 80 faces the magnet 81. In this embodiment, the distance sensor 80 is a magnetic sensor that can measure the relative moving distance of the magnet 81 relative to the distance sensor 80.

The position of the distance sensor 80 is fixed. On the other hand, the movable table 21, the piston 51 and the movable shaft 13b can move as a whole. Therefore, when the movable shaft 13b moves in a direction approaching the reference axis 13a and in a direction away from the reference axis 13a, the relative position of the magnet 81 fixed to the movable table 21 with respect to the distance sensor 80 changes. The moving distance of the magnet 81 is equivalent to the moving distance of the movable shaft 13b. Therefore, the distance sensor 80 can measure the moving distance of the movable shaft 13b. The moving distance of the movable shaft 13b is the relative position of the movable shaft 13b with respect to the predetermined reference position. Hereinafter, the relative position of the movable shaft 13b relative to the predetermined reference position is sometimes simply referred to as the position of the movable shaft 13b.

The distance sensor 80 is connected to the motion control unit 40, and the distance sensor 80 sends the measured value of the moving distance of the movable shaft 13b (the measured value of the position of the movable shaft 13b) to the motion control unit 40. The motion control unit 40 can judge whether the substrate holding device 10 correctly holds the wafer W (whether an abnormality occurs in the substrate holding device 10) by comparing the measured value of the moving distance of the movable shaft 13b (the position of the movable shaft 13b) with a preset threshold value. In one embodiment, the motion control unit 40 can also issue an alarm signal when the measured value of the moving distance (the position of the movable shaft 13b) is greater than the threshold value or less than the threshold value. Furthermore, in one embodiment, the motion control unit 40 may also determine whether the substrate holding device 10 correctly holds the wafer W (whether an abnormality occurs in the substrate holding device 10) by comparing the index value calculated based on the plurality of measured values of the above-mentioned moving distance (the plurality of measured values of the position of the movable shaft 13b) with the preset threshold value. Furthermore, in one embodiment, the motion control unit 40 may also issue an alarm signal when the above-mentioned index value is greater than the threshold value or less than the threshold value. As examples of the above-mentioned index value, the average value of the position of the movable shaft 13b when the roller 11b rotates one or more times and the difference between the maximum value and the minimum value of the position of the movable shaft 13b during the period when the roller 11b rotates one or more times (the amplitude of the position of the movable shaft 13b) can be cited.

As a reason why the measured value of the moving distance of the movable shaft 13b when the movable shaft 13b is moved in a direction close to the reference shaft 13a is less than the threshold value, it can be considered that the wafer W is not correctly held on the substrate holding device 10. As a reason why the measured value of the moving distance is larger than the threshold value, it can be considered that the wafer W is damaged or the wafer falls off (the wafer W falls off or is caught and lost).

Furthermore, in one embodiment, a first threshold and a second threshold smaller than the first threshold may be set for the measured value of the moving distance of the movable shaft 13b. Specifically, the motion control unit 40 is configured to issue an alarm signal when the measured value of the moving distance is larger than the first threshold, and to issue an alarm signal when the measured value of the moving distance is smaller than the second threshold. The range from the second threshold to the first threshold is the range of the moving distance of the movable shaft 13b required for the rollers 11a and 11b to correctly hold the wafer W.

When the movable shaft 13b vibrates during the rotation of the wafer W, the position of the movable shaft 13b (the measured value of the moving distance of the movable shaft 13b) changes with the vibration. Therefore, the motion control unit 40 can detect the vibration of the movable shaft 13b based on the change in the position of the movable shaft 13b during the rotation of the wafer W (the change in the measured value of the moving distance of the movable shaft 13b). The motion control unit 40 can detect the rotation abnormality of the wafer W when the substrate holding device 10 holds the wafer W and rotates it based on the vibration of the movable shaft 13b. As the cause of abnormal rotation of the wafer W, the wear, deformation, damage, dimensional defects of the wafer holding surfaces 31a, 31b of the rollers 11a, 11b or the rotation phase shift of multiple rollers 11a, 11b can be considered.

In one embodiment, the motion control unit 40 may also compare the amplitude of the measured value of the moving distance of the movable shaft 13b (the position of the movable shaft 13b) with a preset threshold value, and judge that vibration occurs in the movable shaft 13b when the amplitude is greater than the threshold value. The motion control unit 40 may also issue an alarm signal when the amplitude is greater than the threshold value.

FIG8 is a diagram showing an example of the position of the movable shaft 13b when a rotational abnormality of the wafer W occurs. The horizontal axis of the figure represents the rotation angle of the roller 11b, and the vertical axis of the figure represents the position of the movable shaft 13b. In FIG8, the closer the movable shaft 13b is to the reference axis 13a, the smaller the value representing the position of the movable shaft 13b, and the farther the movable shaft 13b is from the reference axis 13a, the larger the value representing the position of the movable shaft 13b. The position of the movable shaft 13b being 0 means that within the movable range of the actuator 18, the movable shaft 13b is closest to the reference axis 13a. The rotation angle of the roller 11b being 0° means a predetermined reference angle of the roller 11b. In the example shown in FIG8 , when the rotation abnormality of the wafer W occurs, the movable shaft 13b vibrates greatly and the position of the movable shaft 13b changes greatly. At this time, the amplitude of the position of the movable shaft 13b is larger than the predetermined amplitude threshold. As the cause of the change in the position of the movable shaft 13b shown in FIG8 , the wear, deformation, damage, dimensional defects of the wafer holding surfaces 31a, 31b of the rollers 11a, 11b or the rotation phase shift of the plurality of rollers 11a, 11b can be considered.

The motion control unit 40 compares the amplitude of the position of the movable shaft 13b (the measured value of the moving distance of the movable shaft 13b) with a predetermined amplitude threshold value, and when the amplitude of the position of the movable shaft 13b is greater than the amplitude threshold value, it is determined that the rotation abnormality of the wafer W has occurred. In this specification, the amplitude of the position of the movable shaft 13b is defined as the vibration amplitude of the movable shaft 13b. In the example shown in FIG8, the amplitude of the movable shaft 13b is the difference between the maximum value of the position of the movable shaft 13b and the minimum value of the position of the movable shaft 13b during the period when the roller 11b rotates one or more times. In one embodiment, the motion control unit 40 may also compare the amplitude of the position of the movable shaft 13b (the measured value of the moving distance of the movable shaft 13b) during the time from the first rotation time to the second rotation time of the roller 11b with a predetermined amplitude threshold.

Furthermore, in one embodiment, the motion control unit 40 may also issue an alarm signal when the amplitude of the position of the movable shaft 13b is larger than the amplitude threshold. Furthermore, in one embodiment, the motion control unit 40 may also issue a command to the motors 29a and 29b to stop the motion of the motors 29a and 29b when the amplitude of the position of the movable shaft 13b is larger than the amplitude threshold.

FIG9 is a diagram showing another example of the position of the movable shaft 13b when a rotational abnormality of the wafer W occurs. The details of this embodiment that are not specifically described are the same as the embodiment described with reference to FIG8 , and therefore their repeated description is omitted. In the example shown in FIG9 , the average value of the position of the movable shaft 13b when the roller 11b rotates more than one circle is smaller than the initial average value and the predetermined lower limit threshold value. In this embodiment, the initial average value is the average value of the movable shaft position (measured value) when the rollers 11a and 11b are not in use (not worn). As a cause of the position change of the movable shaft 13b shown in FIG9 , wear, deformation, damage or dimensional defects of the wafer holding surfaces 31a and 31b of the rollers 11a and 11b can be considered. The dotted line L1 in FIG9 represents the average value of the position of the movable shaft 13b during the rotation of the wafer W when the wafer holding surfaces 31a and 31b are damaged.

The motion control unit 40 compares the average value of the position of the movable shaft 13b when the roller 11b rotates one or more times (the average value of the measured value of the moving distance of the movable shaft 13b) with a predetermined lower limit threshold value, and when the average value of the position of the movable shaft 13b is less than the lower limit threshold value, it is determined that a rotation abnormality of the wafer W has occurred. In one embodiment, the motion control unit 40 may also compare the average value of the position of the movable shaft 13b when the roller 11b rotates one or more times (the average value of the measured value of the moving distance of the movable shaft 13b) with a predetermined upper limit threshold value, and when the average value of the position of the movable shaft 13b is greater than the upper limit threshold value, it is determined that a rotation abnormality of the wafer W has occurred. As an example of the reason why the average value of the position of the movable shaft 13b becomes larger than the upper limit threshold, it can be considered that the wafer W is not correctly held on the substrate holding device 10. According to the setting of the reference position of the movable shaft 13b described above, due to wear, deformation, damage or dimensional defects of the wafer holding surfaces 31a and 31b of the rollers 11a and 11b, the average value of the position of the movable shaft 13b may be larger than the upper limit threshold.

In one embodiment, the motion control unit 40 may also issue an alarm signal when the average value of the position of the movable shaft 13b when the roller 11b rotates more than one circle is less than the lower limit threshold value (or the average value of the position of the movable shaft 13b when the roller 11b rotates more than one circle is greater than the upper limit threshold value). Furthermore, in one embodiment, the motion control unit 40 may also issue an instruction to the motors 29a and 29b to stop the action of the motors 29a and 29b when the average value of the position of the movable shaft 13b when the roller 11b rotates more than one circle is less than the lower limit threshold value (or the average value of the position of the movable shaft 13b when the roller 11b rotates more than one circle is greater than the upper limit threshold value). As an example of an alarm signal, a signal that prompts the operator to replace the rollers 11a and 11b can be cited.

According to the embodiment described with reference to FIG9, the motion control unit 40 can detect the abnormality of the rollers 11a and 11b regardless of whether the wafer holding surfaces 31a and 31b of the rollers 11a and 11b are worn evenly or unevenly. The embodiment described with reference to FIG8 and the embodiment described with reference to FIG9 can also be combined. For example, the motion control unit 40 can also judge as abnormal when the amplitude of the position of the movable shaft 13b is larger than the amplitude threshold, or when the average value of the position of the movable shaft 13b when the roller 11b rotates more than one circle is smaller than the lower limit threshold, and issue an alarm signal.

The non-contact distance sensor 80 can accurately measure the moving distance of the movable shaft 13b without being affected by the vibration even when the movable shaft 13b vibrates. In this embodiment, a plurality of non-contact distance sensors 80 are provided to measure the moving distances of the plurality of movable shafts 13b respectively. In one embodiment, a single non-contact distance sensor 80 can also be provided to measure the moving distance of one of the plurality of movable shafts 13b.

In one embodiment, as shown in FIG. 10 , the distance sensor 80 may also be a non-contact optical sensor. The details of this embodiment not specifically described are the same as those of the embodiments described with reference to FIG. 5 , FIG. 8 , and FIG. 9 , and therefore, the repeated description thereof is omitted. The distance sensor 80 of this embodiment comprises: a sensor head 84 having a light-emitting portion and a light-receiving portion (not shown) at the top; a converging lens 85 for converging the light emitted from the sensor head 84; an amplifier 93 connected to the sensor head 84 via a light-emitting optical cable 92A and a light-receiving optical cable 92B; and a distance calculator 94 electrically connected to the amplifier 93. The converging lens 85 is mounted on the top of the sensor head 84.

The sensor head 84 is fixed to the outside of the actuator 18, and the top of the sensor head 84 is arranged toward the movable table 21. More specifically, in the present embodiment, a sensor target 88 is mounted on the movable table 21, and the top of the sensor head 84 is arranged toward the sensor target 88. The sensor target 88 has the property of reflecting light. As an example of the sensor target 88, a component made of a ceramic material or a metal can be cited. The amplifier 93 and the distance calculator 94 are located away from the actuator 18.

The amplifier 93 has a light source 93a that emits light and a light intensity meter 93b that measures the intensity of the reflected light. The light emitted from the light source 93a of the amplifier 93 is transmitted to the sensor head 84 through the light projection cable 92A. The sensor head 84 guides the light toward the sensor target 88 through the focusing lens 85, and receives the reflected light from the sensor target 88. The reflected light is transmitted to the amplifier 93 through the light receiving cable 92B. The light intensity meter 93b of the amplifier 93 measures the intensity of the reflected light. The amplifier 93 sends the measured value of the intensity of the reflected light to the distance calculator 94, and the distance calculator 94 converts the measured value of the intensity of the reflected light into a distance. The distance obtained by the distance calculator 94 is the moving distance of the movable shaft 13b. According to such a structure, the distance sensor 80 of this embodiment can measure the moving distance of the movable shaft 13b. The distance calculator 94 is connected to the motion control unit 40, and the distance calculator 94 sends the measured value of the moving distance of the movable shaft 13b to the motion control unit 40. In one embodiment, the distance sensor 80 may not have the converging lens 85. The sensor head 84 may also guide light to the sensor target 88 without passing through the converging lens 85, and receive reflected light from the sensor target 88 without passing through the converging lens 85.

As described above, among the components constituting the distance sensor 80, only the sensor head 84 is mounted on the actuator 18. The sensor head 84 has only the function of irradiating light and receiving reflected light, so the sensor head 84 itself is very compact.

In one embodiment, the sensor head 84 and the converging lens 85 may also be arranged in the pressure chamber 57a (or in the pressure chamber 57b). In this case, the top of the sensor head 84 is arranged toward the central portion 71a (or central portion 71b) of the partition film 55a (or partition film 55b), and the sensor head 84 guides light to the central portion 71a (or central portion 71b) and receives reflected light from the partition film 55a (or partition film 55b). A sensor target having a property of reflecting light may also be fixed to the central portion 71a (or central portion 71b). Furthermore, in one embodiment, the distance sensor 80 may also be a laser displacement meter.

In the embodiment described with reference to FIGS. 1 to 10 , the substrate holding device 10 has two reference axes 13a, two movable axes 13b, two actuators 18, two movable tables 21, and two linear guides 26 arranged around the center axis CP, but the number and arrangement intervals of these components are not limited to this embodiment. In one embodiment, the substrate holding device 10 may also have a movable axis 13b and two or more reference axes 13a arranged around the center axis CP at appropriate intervals. In this case, the substrate holding device 10 has an actuator 18, a movable table 21, and a linear guide 26.

Furthermore, in one embodiment, the substrate holding device 10 may also have three or more movable shafts 13b and three or more reference shafts 13a arranged around the center axis CP at appropriate intervals. In this case, the substrate holding device 10 has three or more actuators 18, three or more movable tables 21, and three or more linear guides 26. Furthermore, in one embodiment, the motion control unit 40 may also be composed of a plurality of motion control units having a storage device and a computing device. In one example, one of the plurality of motion control units may be connected to the motor 29a, the motor 29b, and another may be connected to the distance sensor 80.

FIG. 11 is a top view schematically showing an embodiment of a substrate processing device having the substrate holding device 10 described with reference to FIG. 1 to FIG. 10 , and FIG. 12 is a side view of the substrate holding device 10 shown in FIG. 11 . In this embodiment, the substrate processing device 100 has the substrate holding device 10 and a processing head 200, and the processing head 200 processes the first surface 1 of the wafer W by bringing a processing tool 201 into contact with the first surface 1 of the wafer W held by the substrate holding device 10 . The processing head 200 is arranged on the lower side of the wafer W held by the substrate holding device 10, and the position of the processing head 200 is fixed.

In the present embodiment, the first surface 1 of the wafer W is the back side of the wafer W where no device is formed or where no device is planned to be formed, i.e., the non-device surface. The second surface 2 of the wafer W on the opposite side of the first surface 1 is the surface where a device is formed or where a device is planned to be formed, i.e., the device surface. In the present embodiment, the wafer W is horizontally held on the substrate holding device 10 with its first surface 1 facing downward.

The specific operation of the substrate processing device 100 of this embodiment is as follows. The substrate holding device 10 makes the plurality of rollers 11a and 11b contact the periphery of the wafer W, rotates the plurality of rollers 11a and 11b around their respective axes, and makes the plurality of rollers 11a and 11b perform circular motion, thereby rotating the wafer W around its axis and performing circular motion, and makes the processing tool 201 contact the first surface 1 of the rotating and circularly moving wafer W through the processing head 200, thereby processing the first surface 1 of the wafer W.

In this embodiment, the processing tool 201 is longer than the radius of the wafer W, one end of the processing tool 201 extends outward from the periphery of the wafer W, and the other end extends beyond the center axis CP of the substrate holding device 10. Therefore, the processing head 200 can make the processing tool 201 contact the entire first surface 1 of the rotating wafer W. As a result, the processing tool 201 can process the entire first surface 1 of the wafer W including the outermost portion. The processing head 200 is arranged at a position where it does not contact the rollers 11a, 11b and the eccentric shafts 13a, 13b when the wafer W performs circular motion.

According to this embodiment, the substrate holding device 10 can make the wafer W perform circular motion while rotating the wafer W around its axis with a simple structure. The combination of such circular motion and rotation around the axis of the wafer W can increase the speed of each point on the surface of the wafer W. Therefore, the relative speed between the processing tool 201 and the surface of the wafer W increases, thereby increasing the processing speed of the wafer W.

In one embodiment, the processing tool 201 may also be a grinding tool for grinding the wafer W. As an example of a grinding tool, a grinding belt and a grindstone may be cited. Furthermore, in one embodiment, the processing tool 201 may also be a cleaning tool for cleaning the wafer W. As an example of a cleaning tool, a cleaning belt may be cited. As an example of a cleaning belt, a belt made of non-woven fabric may be cited.

The above-mentioned embodiments are recorded for the purpose of enabling people with common knowledge in the technical field to which the present invention belongs to implement the present invention. Various variations of the above-mentioned embodiments can certainly be achieved by those skilled in the art who are familiar with the field, and the technical concept of the present invention can also be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is interpreted as the widest scope of the technical concept defined by the scope of the patent application.

10: Substrate holding device 11a, 11b: Roller 13a: Eccentric shaft, reference shaft 13b: Eccentric shaft, movable shaft 14a, 14b: First shaft 15a, 15b: Second shaft 16a, 16b: Intermediate shaft 17a, 17b: Counterweight 18: Actuator 19: Bearing 20: Bottom plate 21: Movable table 23: Connecting member 24: Bearing 26: Linear guide 27a, 27b: Motor support 28a, 28b: Coupling 29a, 29b: Motor 31a, 31b: Wafer holding surface (substrate holding surface) 4: Motion control unit 40a: Storage device 40b: Calculation device CP: Central axis of substrate holding device e: Eccentric distance of first axis W: Wafer

Claims (16)

A substrate holding device, which makes a substrate perform circular motion while rotating the substrate around the axis of the substrate, comprises: a plurality of rollers, which can contact the peripheral portion of the substrate; a plurality of motors, which rotate the plurality of rollers; a plurality of eccentric shafts, which are arranged around a predetermined central axis; a plurality of actuators, which respectively have a plurality of pistons; and a plurality of movable tables, which are respectively connected to the plurality of pistons, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, The plurality of rollers are fixed to the plurality of second shafts, respectively, and the plurality of first shafts are connected to the plurality of motors, respectively. The plurality of eccentric shafts are composed of a plurality of movable shafts and a plurality of reference shafts. The plurality of movable tables have a plurality of bearings and a plurality of connecting parts, and the plurality of bearings support the plurality of movable shafts rotatably, and the plurality of connecting parts are fixed to the plurality of pistons. The plurality of actuators are connected to the plurality of movable shafts through the plurality of movable tables, respectively. The plurality of actuators are configured to move the plurality of movable shafts and the plurality of movable tables integrally in a direction approaching the plurality of reference shafts and in a direction away from the plurality of reference shafts. According to the substrate holding device described in claim 1, the plurality of eccentric shafts further have a plurality of intermediate shaft portions, which connect the plurality of first shaft portions with the plurality of second shaft portions, and the plurality of first shaft portions are respectively fixed to the plurality of intermediate shaft portions, and the plurality of second shaft portions are respectively fixed to the plurality of intermediate shaft portions. The substrate holding device according to claim 1 further comprises a motion control unit that causes the plurality of motors to rotate at the same speed and in the same phase. The substrate holding device according to claim 1, wherein the directions approaching the plurality of reference axes and the directions away from the plurality of reference axes are the directions toward the center axis and the directions away from the center axis. A substrate holding device, which makes a substrate perform circular motion while rotating the substrate around the axis of the substrate, comprises: a plurality of rollers, which can contact the peripheral portion of the substrate; a plurality of motors, which rotate the plurality of rollers; a plurality of eccentric shafts, which are arranged around a predetermined central axis; and a plurality of actuators, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, respectively; the plurality of rollers are respectively fixed to the plurality of second shaft portions, the plurality of first shaft portions are respectively connected to the plurality of motors, The plurality of eccentric shafts are composed of a plurality of movable shafts and a plurality of reference shafts. The plurality of actuators are respectively connected to the plurality of movable shafts. The plurality of actuators are configured to move the plurality of movable shafts in directions approaching the plurality of reference shafts and in directions away from the plurality of reference shafts. The plurality of actuators respectively include: A piston; A housing, which is disposed away from the piston; and A partition membrane, which forms a pressure chamber between the piston and the housing. The partition membrane has: A central portion, which contacts the end of the piston; An inner wall portion, which is connected to the central portion and extends along the side of the piston; A folded portion connected to the inner wall portion and having a curved cross section; and an outer wall portion connected to the folded portion and located on the outer side of the inner wall portion. A substrate holding device, which makes a substrate perform circular motion while rotating the substrate around the axis of the substrate, comprises: a plurality of rollers, which can contact the peripheral portion of the substrate; a plurality of motors, which rotate the plurality of rollers; a plurality of eccentric shafts, which are arranged around a predetermined central axis; and a plurality of actuators, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, respectively; the plurality of rollers are respectively fixed to the plurality of second shaft portions, the plurality of first shaft portions are respectively connected to the plurality of motors, The plurality of eccentric shafts are composed of a plurality of movable shafts and a plurality of reference shafts. The plurality of actuators are respectively connected to the plurality of movable shafts. The plurality of actuators are configured to move the plurality of movable shafts in directions approaching the plurality of reference shafts and in directions away from the plurality of reference shafts. The substrate holding device also has: At least one non-contact distance sensor, which measures the moving distance of at least one movable shaft among the plurality of movable shafts; and A motion control unit, the motion control unit is configured to judge whether the substrate holding device is abnormal by comparing the measured value of the moving distance or an index value calculated based on a plurality of measured values of the moving distance with a preset threshold value, The index value is an average value of the position of at least one of the plurality of movable shafts when the plurality of rollers rotate one circle or more. A substrate holding device, which makes a substrate perform circular motion while rotating the substrate around the axis of the substrate, comprises: a plurality of rollers, which can contact the peripheral portion of the substrate; a plurality of motors, which rotate the plurality of rollers; a plurality of eccentric shafts, which are arranged around a predetermined central axis; and a plurality of actuators, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, respectively; the plurality of rollers are respectively fixed to the plurality of second shaft portions, the plurality of first shaft portions are respectively connected to the plurality of motors, The plurality of eccentric shafts are composed of a plurality of movable shafts and a plurality of reference shafts. The plurality of actuators are respectively connected to the plurality of movable shafts. The plurality of actuators are configured to move the plurality of movable shafts in directions approaching the plurality of reference shafts and in directions away from the plurality of reference shafts. The substrate holding device also has: At least one non-contact distance sensor, which measures the moving distance of at least one movable shaft among the plurality of movable shafts; and A motion control unit, the motion control unit is configured to judge whether the substrate holding device is abnormal by comparing the measured value of the moving distance or an index value calculated based on a plurality of measured values of the moving distance with a preset threshold value, The index value is the difference between the maximum value and the minimum value of the position of at least one of the plurality of movable shafts during the period when the plurality of rollers rotate for more than one circle. The substrate holding device according to claim 1, wherein the plurality of actuators are configured to enable the plurality of movable shafts to move independently; The direction of movement of one of the plurality of movable shafts is different from the direction of movement of another of the plurality of movable shafts. A substrate holding device according to claim 8, wherein the direction of movement of one of the plurality of movable axes and the direction of movement of another of the plurality of movable axes are a direction toward the center axis and a direction away from the center axis. A substrate holding device that causes a substrate to perform circular motion while causing the substrate to rotate about the axis of the substrate, comprising: a plurality of rollers that can contact the peripheral portion of the substrate; a plurality of motors that cause the plurality of rollers to rotate; a plurality of eccentric shafts that are arranged around a predetermined central axis; an actuator having a piston; and a movable table that is connected to the piston, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, respectively, The plurality of rollers are fixed to the plurality of second shafts, respectively, and the plurality of first shafts are connected to the plurality of motors, respectively. The plurality of eccentric shafts are composed of a movable shaft and a plurality of reference shafts. The movable table has a bearing and a connecting member, the bearing supports the movable shaft rotatably, and the connecting member is fixed to the piston. The actuator is connected to the movable shaft via the movable table. The actuator is configured to move the movable shaft and the movable table integrally toward and away from the plurality of reference shafts. The actuator comprises: a piston; a housing, the housing being arranged away from the piston; and A partition membrane forms a pressure chamber between the piston and the housing, wherein the partition membrane has: a central portion in contact with the end of the piston; an inner wall portion connected to the central portion and extending along the side of the piston; a folded portion connected to the inner wall portion and having a curved cross section; and an outer wall portion connected to the folded portion and located on the outer side of the inner wall portion. According to the substrate holding device described in claim 10, the plurality of eccentric shafts further have a plurality of intermediate shaft portions, which connect the plurality of first shaft portions with the plurality of second shaft portions, the plurality of first shaft portions are respectively fixed to the plurality of intermediate shaft portions, and the plurality of second shaft portions are respectively fixed to the plurality of intermediate shaft portions. The substrate holding device according to claim 10, further comprising a motion control unit that causes the plurality of motors to rotate at the same speed and in the same phase. The substrate holding device according to claim 10, wherein the directions approaching the plurality of reference axes and the directions away from the plurality of reference axes are the directions toward the center axis and the directions away from the center axis. A substrate holding device, which makes a substrate perform circular motion while making the substrate rotate around the axis of the substrate, comprises: a plurality of rollers, which can contact the peripheral portion of the substrate; a plurality of motors, which make the plurality of rollers rotate; a plurality of eccentric shafts, which are arranged around a predetermined central axis; and an actuator, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, respectively; the plurality of rollers are respectively fixed to the plurality of second shaft portions, the plurality of first shaft portions are respectively connected to the plurality of motors, The plurality of eccentric shafts are composed of a movable shaft and a plurality of reference shafts. The actuator is connected to the movable shaft. The actuator is configured to move the movable shaft in a direction approaching the plurality of reference shafts and in a direction away from the plurality of reference shafts. The actuator comprises: A piston; A housing, which is arranged away from the piston; and A partition film, which forms a pressure chamber between the piston and the housing. The substrate holding device further comprises: A non-contact distance sensor, which measures the moving distance of the movable shaft; and A motion control unit, the motion control unit is configured to judge whether the substrate holding device is abnormal by comparing the measured value of the moving distance or an index value calculated based on a plurality of measured values of the moving distance with a preset threshold value, The index value is an average value of the position of the movable shaft when the plurality of rollers rotate more than one circle. A substrate holding device, which makes a substrate perform circular motion while making the substrate rotate around the axis of the substrate, comprises: a plurality of rollers, which can contact the peripheral portion of the substrate; a plurality of motors, which make the plurality of rollers rotate; a plurality of eccentric shafts, which are arranged around a predetermined central axis; and an actuator, the plurality of eccentric shafts having a plurality of first shaft portions and a plurality of second shaft portions, the plurality of second shaft portions being eccentric from the plurality of first shaft portions, respectively; the plurality of rollers are respectively fixed to the plurality of second shaft portions, the plurality of first shaft portions are respectively connected to the plurality of motors, The plurality of eccentric shafts are composed of a movable shaft and a plurality of reference shafts. The actuator is connected to the movable shaft. The actuator is configured to move the movable shaft in a direction approaching the plurality of reference shafts and in a direction away from the plurality of reference shafts. The actuator comprises: A piston; A housing, which is arranged away from the piston; and A partition film, which forms a pressure chamber between the piston and the housing. The substrate holding device further comprises: A non-contact distance sensor, which measures the moving distance of the movable shaft; and A motion control unit, the motion control unit is configured to judge whether the substrate holding device is abnormal by comparing the measured value of the moving distance or an index value calculated based on a plurality of measured values of the moving distance with a preset threshold value, The index value is the difference between the maximum value and the minimum value of the position of the movable shaft during the period when the plurality of rollers rotate for more than one circle. A substrate processing device comprising: The substrate holding device as described in any one of claims 1 to 15; and A processing head that brings a processing tool into contact with a first surface of a substrate to process the first surface.