JP2003068829A - Substrate transport system and substrate processing apparatus - Google Patents

Abstract

[PROBLEMS] To provide a practical configuration capable of collectively detecting positions of a plurality of substrates, and to bring about significant improvements such as an improvement in productivity. A substrate transport system transports two substrates simultaneously by a transport robot having two forks, each holding a substrate. The control unit 81 controls the drive system of the transport robot 10 to position the forks 1 and 2 at the monitoring position. At this time, an image of a space assumed to be occupied by the substrate 9 is captured by the image sensor 82. The image from the image sensor 82 is processed by the image processing unit 83,
From the processing result, the determination unit 84 determines whether each substrate 9 is held by the forks 1 and 2 and located at a predetermined position on the forks 1 and 2. In the substrate processing apparatus provided with the substrate transfer system, a monitoring position is set in a transfer chamber 86 provided inside the transfer robot 10, and the image pickup element 82 takes an image through a monitor window 862 of the transfer chamber 86.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus such as a semiconductor manufacturing apparatus provided with a substrate transfer system for transferring a substrate.

[0002]

2. Description of the Related Art A substrate processing apparatus such as a semiconductor manufacturing apparatus used when manufacturing various semiconductor devices or a liquid crystal substrate processing apparatus used when manufacturing a liquid crystal display transfers a substrate to a target position. A substrate transfer system is provided. In a single-wafer type apparatus that processes substrates one by one, many substrate transfer systems also transfer substrates one by one. This type of substrate transfer system often uses an articulated transfer robot having an arm that holds the substrate at its tip.

On the other hand, in the substrate processing apparatus, it is often required that the substrate be accurately transported to a predetermined position in the processing chamber. The reason for this is that, generally speaking, the uniformity and reproducibility of the processing may be deteriorated unless the substrate is always disposed in a predetermined position in the processing chamber with high accuracy. In many cases, the substrate is placed and processed on the upper surface of a pedestal-shaped substrate holder provided in the processing chamber. At this time, for example, in the case of the film forming process, the thin film is deposited on the region of the surface area of the substrate holder which is not covered by the substrate. Therefore, if the mounting position of the substrate is different, the film forming process of the previous time is performed. The substrate is placed on the deposited thin film, which causes particles (granular dust) to adhere to the back surface of the substrate. Also,
In the case of etching treatment, the surface area of the substrate holder other than the area on which the substrate is placed is subjected to etching-resistant surface treatment, but the area on which the substrate is placed has thermal contact properties. In consideration of the above, such a surface treatment is not applied. Therefore, if the mounting position of the substrate is deviated, a portion where the surface treatment is not performed is exposed and the substrate holder is etched to cause particles.

Further, it is required that the substrates are always arranged at the same position, and that the circumferential arrangement position (the position in the rotation direction when the substrate is rotated about the center of rotation) is always the same position. There is. Again, this is generally because of the reproducibility of the process. In addition, when a substrate is arranged, and a member having a shape adapted to the contour shape of the substrate is present in the vicinity, there is a problem that if the arrangement position of the substrate in the circumferential direction shifts, the member will interfere. For example, when the substrate is a semiconductor wafer having an orientation flat (hereinafter, orientation flat) and the substrate holder has a concave portion conforming to its shape and the substrate is dropped into the concave portion, the orientation flat portion is displaced. If so, the substrate will not be dropped into the recess, resulting in a transport error.

Therefore, in the substrate processing apparatus,
It is necessary to detect if the substrate is in the correct position within the processing chamber. However, since it is difficult to directly detect the position in the processing chamber, the position of the substrate is often detected at a detection place set on the transfer line in the processing chamber. For example, when the substrate is held by the tip of the arm of the transfer robot and the substrate is transferred, the reference point of the arm is located at a predetermined position. The position of the substrate at that time is detected by an optical method. For example, a pair of a light emitter and a light receiver are provided at a predetermined position so that the light from the light emitter is partially blocked by the edge of the substrate. Then, the position of the edge of the substrate is known from the amount of the blocked light, and the position of the center of the substrate is calculated based on the data.

[0006]

In the above-mentioned substrate processing apparatus, in order to increase the efficiency of substrate transfer, the transfer robot arm may sometimes hold two substrates at the same time. This is because the whole occupying space is smaller and the cost is lower than the case where two transfer robots are provided. When using such a transfer robot that holds multiple substrates, the position detection of the substrates as described above
This is done by bringing the substrates one by one to the detection location. However, if this is done, it takes time to detect the position, and as a result, the time required to transfer the substrate to the processing chamber becomes long as a whole. Therefore, the merit of using the transfer robot that holds a plurality of substrates is reduced. The invention of the present application has been made in order to solve such a problem, and provides a practical configuration capable of collectively detecting the positions of a plurality of substrates, and is a technical technique that brings about remarkable improvements such as improvement in productivity. It has significance.

[0007]

In order to solve the above problems, the invention according to claim 1 of the present application comprises a substrate holder for holding two or more substrates, and a drive system for driving the substrate holder, A substrate transfer system capable of transferring two or more substrates to a predetermined position while holding them at the same time, wherein a control unit for controlling a drive system to position the substrate holder at a predetermined monitoring position, and a substrate holder When located at the monitoring position, an image sensor that captures an image of the space assumed to be occupied by the two or more substrates held by the substrate holder, and an image processing unit that processes the image from the image sensor, The image processing unit has a configuration including a determination unit that determines whether each of the two or more substrates is located at a predetermined position or is held by the substrate holder. In order to solve the above-mentioned problems, the invention according to claim 2 provides a processing chamber for internally performing a predetermined processing on a substrate, and a processing chamber for carrying an unprocessed substrate into the processing chamber and processing the processed substrate. A substrate processing apparatus comprising: a substrate transfer system for unloading the substrate from the substrate transfer system, wherein the substrate transfer system includes a substrate holder that holds two or more substrates and a drive system that drives the substrate holder. It is possible to convey the substrate to a predetermined position while holding it at the same time, and the control unit that controls the drive system to position the substrate holder at the predetermined monitoring position, and the substrate holder is located at the monitoring position. At this time, an image sensor that captures an image of a space assumed to be occupied by the two or more substrates held by the substrate holder, an image processing unit that processes an image from the image sensor, and a processing result of the image processing unit. Or Has a structure that consists more a determining unit for determining whether it is held in the position to which or the substrate holder at a predetermined position for each of the two or more substrates. In order to solve the above-mentioned problems, the invention according to claim 3 is the structure according to claim 2, wherein the substrate holder and the drive system convey two or more substrates to a predetermined position while conveying them. In addition to configuring the robot, a transfer chamber in which the transfer robot is provided is provided, and the processing chamber and the load lock chamber are hermetically connected to the periphery of the transfer chamber, and The monitoring position has a configuration that it is set in the transfer chamber.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. First, an embodiment of the invention of a substrate transfer system will be described. FIG. 1 is a schematic side view of the substrate transfer system according to the embodiment. The substrate transfer system shown in FIG. 1 includes a substrate holder that holds two or more substrates 9 and a drive system that drives the substrate holder, and a substrate transfer system that simultaneously transfers two or more substrates 9 to a predetermined position. Is. The substrate holder and the drive system form a transfer robot 10.
The transfer robot 10 is mainly composed of a substrate holder, an articulated arm mechanism having the substrate holder at its tip, and a drive system.

FIG. 2 is a front sectional view showing a detailed structure of the transfer robot 10 shown in FIG. 1, and FIG. 3 is a schematic plan view of the transfer robot 10 shown in FIG. The transfer robot 10 includes forks 1 and 2 as substrate holders for holding the substrate 9,
A plurality of arms 31, 32, 4 for holding the forks 1, 2
It is composed of an arm mechanism composed of 1, 42 and an arm drive system for driving the arm mechanism. The arm drive system includes front and rear movement mechanisms 51 and 52 for moving the forks 1 and 2 back and forth via the arms 31, 32, 41 and 42, and the arms 31 and
A rotary motion mechanism 6 for rotating the forks 1 and 2 via the arms 32, 41, 42, and the arms 31, 32, 41, 42.
It comprises vertical movement mechanisms 71 and 72 for vertically moving the forks 1 and 2 via.

One of the major features of this embodiment is that FIG.
As can be seen from FIG. 3 to FIG. 3, two forks 1 and 2 are provided, which are arranged vertically. For convenience of description, the lower fork 1 is referred to as the lower fork 1, and the upper fork 2 is referred to as the upper fork 2. The two forks 1 and 2 have the same shape, that is, a substantially rectangular plate-shaped member provided with a U-shaped cutout. In the present embodiment, it is assumed that a circular substrate 9 such as a semiconductor wafer is transported, and as shown in FIG. 3, the substrate 9 has a U-shaped notch at the center of the arc portion (hereinafter referred to as the center). , Center of the fork) so that it is held at a position that almost coincides with it.

The lower fork 1 has four arms 31, 3
It is held at 2, 41 and 42. Four arms 31,
32, 41, 42 are a pair of left and right arms 31, 41 (hereinafter, lower left first arm 31 connected to the lower fork 1.
And the lower right first arm 41) and the lower left first arm 31.
A lower left second arm 32 connected to the lower left joint part 33 via a lower left joint part 43, and a lower right second arm 42 connected to the lower right first arm 41 via a lower right joint part 43. Has become.
A lower arm fixture 21 is provided at the base of the lower fork 1.

The lower left first arm 31 and the lower right first arm 41 are connected to the lower arm fixture 21 and hold the upper fork 2 via the arm fixture 21. The lower left first arm 31 and the lower right first arm 4
The tip of 1 is connected via a gear mechanism or a belt (not shown). By this connection, during the back-and-forth movement described later,
The orientation of the lower fork 1 is kept constant.

The upper fork 2 has the same structure, and the four arms 34, 35, 44, 45 are a pair of left and right arms 34, 44 connected to the upper fork 2 (hereinafter, the upper left first arm 34). And the upper right first arm 44)
An upper left second arm 35 connected to the upper left first arm 34 via a lower left joint 36, and an upper right first arm 44 connected to an upper right first arm 44 via an upper right joint 46. It has two arms 45. As shown in FIG. 2, the left and right upper first arms 34, 44 and the left and right upper second arms 3 are
The distance from the upper left joint 36 is long.
And the upper left joint 46 is long so as to connect them. Four arms 31 holding the lower fork 1,
32, 41, 42 are the left and right upper first arms 34, 44.
Is located in the space between the left and right upper second arms 35, 45.

Upper ends of the left and right lower joint parts 33 and 43 are respectively fitted into end portions of the lower first arms 31 and 41 via bearings (not shown), and lower ends thereof are lower second arms 32 and 42. Is fitted into the end portion of the bearing through a bearing (not shown). The same applies to the left and right upper joints 36 and 46, and the upper first and second arms 34, 35, 44, and
It is fitted into the end of 45 through a bearing (not shown).

Each of the above four arms 31, 32, 41, 4
2, 34, 35, 44 and 46 are adapted to move the forks 1 and 2 forward and backward by independent forward and backward movement mechanisms 51 and 52, respectively. This point will be described below. First, a back-and-forth movement mechanism (hereinafter, lower-side front-and-back movement mechanism) 51 for moving the lower fork 1 back and forth will be described. The lower-side forward / backward movement mechanism 51 drives the lower-side drive shaft 511 connected to the four arms 34, 35, 44, 45 holding the lower-side fork 1 and the lower-side drive shaft 511 to drive the lower-side drive shaft 511. It is mainly composed of a lower drive source 512 for moving the side fork 1 back and forth.

As shown in FIG. 2, the transfer robot 10 of the present embodiment is coaxial with the robot central axis A.
A lower drive shaft 511 is provided. The lower left second arm 35 and the lower right second arm 45 are provided on the upper end portion of the lower drive shaft 511. The lower left second arm 35 is directly connected to the lower drive shaft 511, while the lower right second arm 45 is connected to the lower drive shaft 511 via a bearing.

The lower drive source 512 is composed of a lower rotor 513 and a lower stator 514 which constitute a motor. At the lower end of the lower drive shaft 511,
The lower rotor 513 is provided, and the lower rotor 5 is provided.
A lower stator 514 is provided so as to surround 13. A lower drive circuit (not shown) is connected to the lower stator 514. When the lower drive circuit operates, the lower stator 514 is energized, and the lower drive shaft 51
The lower drive shaft 511 fixed to 1 is rotated. Lower stator 514 and lower rotor 51
The configuration of 3 can be adopted by arbitrarily selecting the configurations of various motors such as a DC motor, an AC motor, a DC or AC servo motor, and a stepping motor.

Next, a back-and-forth movement mechanism (hereinafter, upper-and-back movement mechanism) 52 for moving the upper fork 2 back and forth will be described. The upper-side forward / backward movement mechanism 52 drives the upper-side drive shaft 521 to move the upper-side fork 2 back and forth by driving the upper-side drive shaft 521 to which the four arms 34, 35, 44, 45 holding the upper-side fork 2 are connected. Upper drive source 52 for movement
It is mainly composed of 2 and. The upper drive shaft 521 is
It is provided so as to surround the lower drive shaft 511. The upper drive shaft 521 has a cylindrical shape and is provided coaxially with the lower drive shaft 511. Upper drive shaft 521
The upper right second arm 45 is connected to the upper end portion of the. The upper left second arm 35 is connected to the lower drive shaft 511 via a bearing.

The upper drive source 522 is also the lower drive source 51.
Similar to the second embodiment, the upper rotor 523 and the upper stator 524 that constitute the motor are configured. An upper rotor 523 is provided at a lower end portion of the upper drive shaft 521, and an upper stator 524 is provided so as to surround the upper rotor 523. Upper stator 524
Is connected to an upper drive circuit (not shown), and the upper stator 524 is energized to rotate the upper rotor 523, thereby rotating the upper drive shaft 521. Upper stator 524 and upper rotor 52
Similarly, as for the configuration of 3, the same configurations of various motors such as a DC motor, an AC motor, a DC or AC servo motor, and a stepping motor can be arbitrarily selected and employed.

On the other hand, as shown in FIG. 2, the lower drive shaft 5
A braking shaft 53 is provided so as to surround the tip portion of 11. The role of the braking shaft 53 is to drive the lower drive source 51.
When 2 or the upper drive source 522 is operated, a braking force is applied so as to convert the rotation of the lower drive shaft 511 or the upper drive shaft 521 into the longitudinal movement of the lower fork 1 or the upper fork 2, A driving force is introduced when the forks 1 and 2 are integrally rotated.

The braking shaft 53 is a short cylindrical member as a whole. As can be seen from FIG. 2, the braking shaft 53 has a stepped shape in which the left half and the right half have different lengths. Then, the left side surface of the braking shaft 53 and the lower end of the lower left joint portion 33 are connected to each other so that the first fixing force transmitting tool 541.
Is provided. The first fixing force transmitting tool 541 is specifically a belt, and is stretched between the braking shaft 53 and the lower left joint portion 33. Further, the second fixing force transmitting tool 542 is provided so as to connect the right side surface of the braking shaft 53 and the lower end of the right left joint portion 43. Second fixing force transmission tool 5
42 is also a belt stretched between the braking shaft 53 and the upper right joint 46.

Next, the operation when the above-mentioned two forks 1 and 2 are moved back and forth will be described. First, when the lower fork 1 is moved back and forth, the lower drive source 512
Is operated to apply a force in the rotational direction to the lower drive shaft 511. As a result, the force in the rotational direction is also applied to the lower left second arm 32 directly connected to the lower drive shaft 511. The force in the rotation direction is applied to the lower left joint 33 and the first fixing force transmitter 54.
1 is transmitted to the braking shaft 53. Since the upper right second arm 45 is connected to the opposite side of the braking shaft 53 via the second fixing force transmission tool 542, the rotational force given to the braking shaft 53 is applied to the upper right second arm. 45,
Finally, it is given to the upper drive shaft 521.

On the other hand, at the same time when the lower drive source 512 is operated, the upper drive source 522 is operated to apply a torque so that the upper drive shaft 521 does not rotate. That is,
The upper drive shaft 521 is braked. Lower left second arm 3
2 is connected to the lower left first arm 31, and the lower left first arm 31 is connected to the lower right first arm 41 via the lower fork 1.
, The lower right first arm 41 is connected to the lower right second arm 42, and the lower right second arm 42 is held by the lower drive shaft 511 via a bearing,
As a result of the above braking, when the lower left second arm 32 makes an arc motion about the lower drive shaft 511, the lower left first arm 31 makes an arc motion about the lower left joint portion 33. .

Along with this, the lower right first arm 41 also performs an arcuate movement which is line-symmetrical to the lower left first arm 31. Then, the lower right second arm 42 follows the circular movement which is line-symmetrical to the lower left second arm 32. As a result of such a symmetrical circular arc movement, as shown in FIG.
Will move back and forth in the direction of its line of symmetry.
Needless to say, the front-back direction depends on the direction of rotation of the lower drive shaft 511. During the back-and-forth movement, the posture of the lower fork 1 does not change and always faces in the back-and-forth movement direction. More precisely, the depth direction of the U-shape of the lower fork 1 is always in the direction of forward and backward movement.

When the upper fork 2 is moved back and forth, it is essentially the same as described above. Upper drive source 5
22 is operated to apply a force in the rotational direction to the upper drive shaft 521, and at the same time, the lower drive source 512 is operated to generate torque in the opposite direction so that the lower drive shaft 511 does not rotate. In accordance with the circular motion of the upper right second arm 45, the upper right first arm 44 and the upper left first arm 34 perform linear symmetrical arc motions, and the upper fork 2 moves back and forth.

As can be seen from the above description, in the first fixing force transmitting tool 541 and the second fixing force transmitting tool 542, the left and right first arms 31, 41, 34, 44 rotate about the drive shafts 511, 521. It conveys the power to control the loss. The first fixing force transmitting tool 541 and the second fixing force transmitting tool 542 are slightly expanded and contracted during the forward and backward movement. As the first fixing force transmitting tool 541 and the second fixing force transmitting tool 542, a mechanism such as a slider can be adopted in addition to the belt.

As can be easily inferred from FIG. 3, the stroke length of the above-mentioned forward and backward movements is such that the left first arm 31, 34 and the right first right arm 41, 44 are in a forward position and the left first arm 31, 34 is in parallel with each other. The distance is between the retracted position in which the arms 31 and 34 and the second right arm 41 and 44 are parallel to each other. The forks 1 and 2 can be retracted until the rear ends of the forks 1 and 2 cross the robot central axis A.

Next, the structure of the rotary motion mechanism 6 for integrally rotating the two forks 1 and 2 will be described. The rotary motion mechanism 6 includes a rotary drive shaft 61 and a rotary drive shaft 6
It is mainly composed of a rotation drive source 62 for driving the motor 1. As shown in FIG. 2, a rotation drive shaft 61 is coaxially provided outside the upper drive shaft 521. The rotation drive shaft 61 has a cylindrical shape, and the upper drive shaft 521 and the like are inserted therein. A connecting rod 63 is fixed to the upper end of the rotary drive shaft 61 and extends upward. The upper end of the connecting rod 63 is fixed to the braking shaft 53. In addition, an insertion hole through which the connecting rod 63 is inserted is provided in the upper end portion of the upper drive shaft 521. This insertion hole is for the drive shaft 6 for rotation.
It has an arc shape coaxial with 1.

A rotation drive source 62 for integrally rotating the two forks 1 and 2 includes a rotation rotor 621 provided on a side surface of a lower end portion of the rotation drive shaft 61 and a rotation rotor 621. It is mainly composed of a rotating stator 622 for rotating and a rotating drive circuit (not shown) for energizing the rotating stator 622. When the rotation drive circuit operates, the rotation stator 622 is energized to rotate the rotation drive shaft 61. Similarly, the lower stator 514 and the lower rotor 513 may have the same configurations as those of various motors such as a DC motor.

When the two forks 1 and 2 are integrally rotated, the rotation drive source 62 rotates the rotation drive shaft 61. At this time, the lower drive source 512 and the upper drive source 522 described above are not operated, and the lower drive shaft 511 is not operated.
The upper drive shaft 521 and the upper drive shaft 521 are free (state in which no force is applied). When the rotation drive shaft 61 rotates, the connecting rod 63
The braking shaft 53 also rotates via. As a result, the lower fork 1 and the four arms 31, 32, 41, 42 holding the lower fork 1 rotate integrally through the first fixing force transmitting tool 541, and the second forcing force transmitting tool 542 causes the lower fork 1 to rotate integrally. Upper fork 2 and four arms 34, 35, 4 holding it
4, 45 rotate together. By this rotation, it becomes possible to set the direction of the above-mentioned back-and-forth movement to any direction within the horizontal plane.

Next, the vertical movement mechanisms 71 and 72 for vertically moving the two forks 1 and 2 together will be described.
In this embodiment, two mechanisms for vertical movement are provided. One is a mechanism for vertical movement with a short movement distance (hereinafter, first vertical movement mechanism) 71, and the other is a mechanism for vertical movement with a long movement distance (hereinafter, second vertical movement mechanism). 72.

First, the first vertical movement mechanism 71 will be described. The lower drive shaft 511 and the upper drive shaft 52 described above.
1, the rotary drive shaft 61, and the respective parts connected to the rotary drive shaft 61, are entirely held by a support body 711. More specifically, as shown in FIG. 2, the lower stator 514, the upper stator 524, and the rotating stator 622 are held by the support 711. Between the support 711 and the rotation drive shaft 61, the rotation drive shaft 61 and the upper drive shaft 52.
1 and between the upper drive shaft 521, a holder (not shown) including a bearing is provided. Therefore, each shaft is finally supported by the support body 711, and the upper arms 31, 32, 41, 42, 34, 35, 44, 45.
The group and the two forks 1 and 2 are also supported by the support 711.

The support 711 is cylindrical and has a lower end fixed to the first base plate 712 in a horizontal posture. The first vertical movement mechanism 71 includes a first driven ball screw 713 that is fixed to the lower surface of the first base plate 712 and extends downward, a first driving ball screw 714 that meshes with the first driven ball screw 713, and a first driving ball screw 714. It is mainly composed of a first vertical drive source 715 that rotates the drive ball screw 714.

As shown in FIG. 2, the first driven ball screw 713 is coaxial with the lower drive rod 511 and the like, and is therefore coaxial with the entire transfer robot 10. The first drive ball screw 714 has a cylindrical shape as a whole, and the inner surface thereof is threaded and meshes with the first driven ball screw 714. The first vertical drive source 715 has the same configuration as the lower drive source 512 described above, and the first drive ball screw 71
4, an up / down rotor 716 fixed to the side surface, an up / down stator 717 magnetically coupled to the up / down rotor 716, and an up / down drive circuit (not shown) for electrically driving the up / down stator 717. ing.

When the first up / down drive source 715 operates, the first drive ball screw 7 moves as the up / down rotor 716 rotates.
14 rotates. The first driven ball screw 713 is prevented from rotating by a rotation restricting portion (not shown).
Therefore, the rotation of the first driving ball screw 714 moves the first driven ball screw 713 up and down. Along with this, each support body 711 moves up and down integrally via the first base plate 712, and as a result, the two forks 1 and 2 also move up and down together. The direction of movement is the first vertical drive source 71.
Depending on the direction of rotation by 5.

Next, the second vertical movement mechanism 72 will be described. Below the first base plate 712, the second base plate 7
21 is provided. The second base plate 721 entirely supports the above-mentioned mechanism. Specifically, the first drive ball screw 714 of the first vertical drive source 715 is supported by the second base plate 721 via a bearing. The second vertical movement mechanism 72 is a mechanism for vertically moving the second base plate 721. Specifically, the second vertical movement mechanism 72 includes a second driven ball screw 722 fixed to the second base plate 721, a second driven ball screw 723 that meshes with the second driven ball screw 722, and a second It is mainly composed of a second vertical drive source 724 for rotating the drive ball screw 723.

As shown in FIG. 2, an insertion opening is formed at a corner of the second base plate 721. The second driven ball screw 722 is in the shape of a short cylindrical rod, and its inner surface is threaded. Second driven ball screw 72
2 is fixed to the second base plate 721 such that its end surface surrounds the edge of the insertion opening. The second drive ball screw 723 has a long rod shape extending vertically, is inserted into the insertion opening of the second base plate 721, and is meshed with the second driven ball screw 722. The upper end of the second drive ball screw 723 is attached to the frame 725 via a bearing. The lower end of the second drive ball screw 723 is located below the second base plate 721 and is connected to the second vertical drive source 724 via a gear 727.

The second vertical drive source 724 is a motor such as an AC servo motor. When the second vertical drive source 724 is driven, the second drive ball screw 72 is driven via the gear 727.
3 rotates. Since the second driven ball screw 722 and the second base plate 721 are prevented from rotating by a rotation restricting portion (not shown), they are vertically moved by the rotation of the second drive ball screw 723. As a result, the first base plate 712 also moves up and down, and the two forks 1 and 2 also move up and down together. The second base plate 721 is provided with a linear guide 726 extending parallel to the second drive ball screw 723. The linear guides 726 are provided at even positions in the order of 2-3, and guide the vertical movement of the second base plate 721 to be stable.

The transfer robot 10 described above is provided with means for monitoring the operation of the two forks 1 and 2. The monitoring means includes a lower leaf drive shaft 511, an upper drive shaft 521,
It is means for monitoring the rotation angles of the rotation drive shaft 61 and the first driven ball screw 713, and has the same structure as a rotary encoder using an optical sensor or a magnetic sensor. The monitoring means finally detects the current position of each fork 1, 2.

The operation of the transfer robot 10 having the above structure will be described below. In the initial state of the transfer robot 10, each arm 31, 32, 41, 42, 34, 35,
44 and 45 are in a contracted state, and the two forks 1,
Both are located on the robot center axis A. First, an operation in which one of the forks 1 and 2 receives and holds the board 9 in another place will be described.

First, at the height position of the place where the substrate 9 is,
In order to position one of the forks 1 and 2 (hereinafter, the lower fork 1 as an example), two vertical movement mechanisms 7
One of 1, 72 is driven. The lower fork 1 is the substrate 9
When the position of the fork is reached, the rotation drive source 62 is operated so that the fork reference direction is oriented in the direction of the horizontal line connecting the robot central axis A and the center of the substrate 9 to perform the rotational movement.
Also at this time, each arm 31, 32, 41, 42 is in a contracted state, and the two forks 1 and 2 are on the robot central axis A.

When the center of the substrate 9 and the fork reference direction are oriented in the direction of the horizontal line connecting the robot central axis A and the center of the substrate 9, the lower drive source 512 is moved so that the lower fork 1 moves forward. Drive. The forward distance of the lower fork 1 is set so that the lower fork 1 enters the lower side of the substrate 9 and the fork center coincides with (or is on the same vertical line as) the center of the substrate 9. Then, the first or second vertical drive sources 715 and 724 are operated to raise the lower fork 1 by a predetermined short distance. As a result, the substrate 9 is placed on the lower fork 1.

Next, the substrate 9 thus held is
The operation of transporting to another place will be described. First, the lower drive source 512 is operated to retract the lower fork 1 from the position where the substrate 9 is received. The retreat distance is set so that the center of the substrate 9 coincides with the robot center axis A. When the lower fork 1 is retracted until the center of the substrate 9 coincides with the robot center axis A, the first or second up-and-down drive sources 715 and 724 are operated to convey the substrate 9 and finally position it. The lower fork 1 is positioned at the height of the place where it should be carried (hereinafter, the carrying place).

Then, the rotation drive source 62 is operated so that the fork reference direction of the lower fork 1 is oriented in the direction of the horizontal line connecting the transfer location and the robot central axis A. When the fork reference direction of the lower fork 1 is oriented in the direction of the horizontal line connecting the transfer location and the robot central axis A, the lower drive source 512 is operated to move the lower fork 1 forward to transfer the substrate 9. Transport to a place. Of course, in the above operation, the order of the vertical movement for adjusting the height and the rotational movement for adjusting the direction may be reversed.

Now, another major feature of the substrate transfer system of this embodiment is that the forks 1 and 2 as substrate holders are positioned at predetermined monitoring positions by controlling the drive system, as shown in FIG. The control unit 81 and the image sensor 82 that captures an image of the space assumed to be occupied by the substrate 9 held by the forks 1 and 2 when the forks 1 and 2 are located at the monitoring position.
And an image processing unit 83 that processes an image from the image sensor 82.
From the processing result of the image processing unit 83, whether or not each substrate 9 is correctly held by the forks 1 and 2 and each substrate 9
Is provided with a determination unit 84 for determining whether the vehicle is located at a predetermined position. Hereinafter, these configurations will be described in detail.

First, as the image pickup device 82, a CCD area image sensor is used in this embodiment.
As shown in FIG. 1, the image pickup element 82 is provided such that its optical axis (axis passing through the center of the incident surface and perpendicular to the incident surface) 82A is oblique to the robot central axis A. In the present embodiment, the monitoring position is set at a position where the fork centers of the two forks 1 and 2 are located on the robot central axis A. The image pickup element 82 is provided at a position where the periphery of each substrate 9 can be imaged when each substrate 9 is held by each fork 1, 2 when each fork 1, 2 is located at this position. That is, there is a positional relationship in which the peripheral edges of the substrates 9 on the forks 1 and 2 are within the view angle (solid angle) of the image sensor 82 shown in FIG. As will be described later, the substrate 9
There is a case where the image is displaced and held by the forks 1 and 2, but even if the image is displaced, the peripheral edge is imaged by the image sensor 82 unless it is extremely large.

Although details of the image processing unit 83 are not shown, the image processing unit 83 is configured by a processor as hardware and an image processing program executed by the processor. The image processing unit 83 processes the image data sent from the image pickup device 82 and extracts information necessary for the determination by the determination unit 84.

More specifically, the data sent from the image pickup device 82 is the output signal of each cell of the CCD. The image processing unit 83 converts this data into coordinates set on the incident surface of the image sensor 82 and processes it. FIG. 4 is a diagram illustrating the coordinates of image data. As shown in FIG. 4, the origin of the coordinates is set on the optical axis 82A of the image sensor 82. The X axis is the optical axis 8 of the image sensor 82.
It is set on a horizontal line that intersects 2A at a right angle. Further, the Y axis is set on a line orthogonal to both the optical axis 82A of the image sensor 82 and the X axis.

FIG. 5 is a diagram for explaining the outline of the image processing program. The image processing program performs image processing for extracting the contour of the captured image for the image data on the coordinates set as described above. Image sensor 8
In the image data of the imaged image 2, the substrate 9 and the members such as the arm and the other background portions have different shades (intensity of incident light) or colors (wavelength of incident light). Therefore, when the image data is scanned on the coordinate plane, the coordinate group corresponding to the contours of the substrate 9 or the member can be extracted by extracting the place where the value changes abruptly. FIG. 5 (1) is a diagram showing the primary processing data subjected to the image processing in this way.

Next, the image processing program is shown in FIG.
A coordinate group corresponding to the peripheral edge of the substrate 9 is specified from the primary processing data shown in FIG. In the image processing unit 83, data on the curvature of the diameter or the peripheral edge of the substrate 9 is stored in advance. The image processing program calls this data, and according to this data, distinguishes the line group of the primary processing data shown in FIG. Only the coordinate group corresponding to the periphery is extracted. The data (secondarily processed data) thus obtained is shown in FIG. The judgment unit 84 is shown in FIG.
The secondary processing data shown in (2) is sent.

Next, the structure of the judging section 84 will be described. The determination unit 84 includes a processor as hardware and a determination program executed by the processor. The determination program follows each of the forks 1 and 2 according to the secondary processing data output from the image processing unit 83.
A final judgment is made as to whether the substrate 9 is held on the upper side and whether the position of the substrate 9 is correct.

First, according to the secondary processing data from the image processing section 83, the presence or absence of the substrate 9 on the forks 1 and 2 is first determined. This determination is made by dividing the image data into two areas. As shown in FIG. 5 (2), in this embodiment, the image data is divided into two upper and lower regions with the X axis as a boundary. The upper region is a region where the contour of the substrate 9 is assumed to be captured when the substrate 9 is held by the upper fork 2, and the lower region is the substrate 9 held by the lower fork 1. In this case, it is assumed that the contour of the substrate 9 is captured.

The determination program determines whether the secondary processing data is in the upper area, the lower area, or in any of them. If there is no secondary processing data in the upper area, "no board in upper fork" is output, and if there is no secondary processing data in the lower area,
Outputs "No board on lower fork". If no secondary processing data is output from the image processing program, "no board on both forks" is output.

Next, the judgment program carries out a position judgment step for judging whether or not the position of the board 9 is correct, except when "no boards on both forks" is output. FIG. 6 is a diagram illustrating the position determination step performed by the determination program. In this embodiment, when the board 9 is correctly positioned on each fork 1, 2,
The corner portion between the orientation flat and the arc-shaped portion is the image sensor 82.
It is designed to be within the angle of view. The "correctly positioned" means the position of the substrate 9 in the horizontal direction,
This means that any of the positions in the rotation direction around the center axis of is a correct position, and is hereinafter referred to as a normal position.

Reference data is registered in the judging section 84. The reference data is data created in advance based on image data captured while holding the substrate 9 on each of the forks 1 and 2 while the substrate 9 is positioned at the regular position. This is the data for determining that the substrate 9 is in the regular position. In the position determination step, the determination unit 84 compares the secondary processing data with the reference data and determines whether the deviation is within a predetermined small range. As shown in the lower area of FIG. 6, it is determined that the normal position is present if the deviation is within a predetermined small range, and it is determined that the normal position is not present if the deviation is large as shown in the upper area of FIG. To do. In some cases, a corner portion between the orientation flat and the arc-shaped portion may be detected as a singular point, and it may be determined whether the position is a normal position or not based on the deviation of the position.

The determination of the normal position is made independently for each of the upper area and the lower area described above. That is,
The reference data in the upper area and the secondary processing data in the upper area are compared to determine whether the substrate 9 on the upper fork 2 is in the normal position. Then, the reference data in the upper area and the secondary processing data in the upper area are compared with each other to determine whether the substrate 9 on the upper fork 2 is in the normal position.

According to the substrate transfer system of the present embodiment having the above configuration and operation, the two substrates 9 can be transferred at one time, and therefore the transfer efficiency is high. In addition, since it is possible to carry the substrate 9 while checking whether the substrate 9 is held by the substrate holder at the proper position, the reliability is also excellent. Further, since it is possible to confirm the holding of the two substrates 9 at the normal position at the same time, the system is more efficient in this respect.

As described above, in the transfer robot 10 of this embodiment, when the substrate 9 is placed on the forks 1 and 2 and is rotated, the center of the substrate 9 is substantially aligned with the center of rotation. . Therefore, the centrifugal force applied to the substrate 9 during rotation is almost zero. Therefore, in this embodiment, the substrate 9 is not displaced on the forks 1 and 2 or dropped from the forks 1 and 2 due to the centrifugal force. Therefore, the system is also highly reliable in this respect.
Also, when the forks 1 and 2 rotate,
Since the center of the substrate 9 is retracted to a position where the center of the substrate 9 coincides with the robot central axis A, the space for rotation can be small.

In this embodiment, the forks 1 and 2 were used as the substrate holder, but the name "fork" is
The shape is attached, and the shape is not limited to this. It is sometimes called a hand or an end effector. It suffices that the substrate holder be capable of holding the substrate 9, and any configuration other than that shown in FIG. 3 can be adopted. In addition to holding the substrate 9 on the upper surface, the substrate 9 may be sandwiched between the left and right edges and held, for example. Further, the substrate 9 for the information recording disk may have a shape in which a circular opening is provided in the center, and in such a case, there is a configuration in which the substrate 9 is held in a vertical posture and held by the edge of the opening. obtain.

The number of substrate holders is not limited to the above-mentioned two, but may be three or more, and may be configured to simultaneously convey three or more substrates 9 while holding them. . In the above-described embodiment, the number of forks 1 and 2 as the substrate holder is two (two substrate holders), but one substrate holder may hold two or more substrates 9. Arms 31, 32, 4 for holding the forks 1, 2
The configurations of 1, 42, 34, 35, 44, 45 are not limited to those described above. Four arms 31, 32, 41, 42, 34, 35, 44, 45 with two left and right
In addition to the configuration in which one fork 1 or 2 is held by one arm, for example, a configuration in which one fork 1, 2 is held by each of the left and right three arms in total may be used.

Next, an embodiment of the invention of the substrate processing apparatus will be described. FIG. 7 is a schematic plan view of an embodiment of the invention of a substrate processing apparatus. The device shown in FIG.
A processing chamber 85 for performing a predetermined process on the substrate, and a substrate transfer system for loading the unprocessed substrate 9 into the processing chamber 85 and unloading the processed substrate 9 from the processing chamber 85. The substrate transfer system has the same configuration as that of the above-described embodiment.

In the apparatus of this embodiment, the transfer chamber 86 in which the transfer robot 10 constituting the substrate transfer system is installed is provided in the center. In the present embodiment, three processing chambers 85 are provided. The transfer chamber 86 is rectangular in plan view, and the three processing chambers 85 are hermetically connected to the three side surfaces of the transfer chamber 86, respectively. A load lock chamber 87 in which the substrate 9 temporarily stays when being transferred between the atmosphere side and the transfer chamber 86 is connected to the other side surface of the transfer chamber 86. In addition, each chamber 85,
A gate valve 88 is provided at the boundary between 86 and 87. In addition, in each chamber 85, 86, 87,
An exhaust system (not shown) for exhausting the inside is provided.

On the atmosphere side of the apparatus, the unprocessed substrate 9
An external cassette 891 for accommodating the processed substrate 9 is provided. On the other hand, in the load lock chamber 87, an in-lock cassette 871 that temporarily accommodates the substrate 9 is provided.
Is provided. Carrying in the substrate 9 to the device or the substrate 9
An external cassette 891 is provided in the load station 890, which is a place for collecting. Then, the substrate 9 is placed between the external cassette 891 and the lock cassette 871.
An auto loader 892 that conveys the paper is provided. The autoloader 892 is an articulated single-arm robot. Also,

FIG. 8 is a schematic side sectional view of the transfer chamber 86 in the substrate processing apparatus shown in FIG. As shown in FIG. 8, a monitor opening 861 is provided on the wall of the transfer chamber 86, and a monitor window 862 is provided so as to hermetically close the monitor opening 861. Then, the above-mentioned image pickup element 82 has the monitor opening 86.
1 and the monitor window 862 so that imaging can be performed through the transfer chamber 86 at a predetermined position.

The structure of the processing chamber 85 in the substrate processing apparatus of this embodiment is not particularly limited and can be appropriately selected according to the content of processing. For example, when performing the sputtering process, a substrate holder for mounting and holding the substrate 9 on the upper surface and a target arranged so as to face the substrate holder are provided in the processing chamber 85.
An exhaust system for exhausting the inside of the processing chamber 85 and a gas introduction system for introducing a process gas into the processing chamber 85 are provided. Behind the target is a magnet unit that achieves a magnetron discharge. A process gas such as argon is introduced to apply a negative high voltage or DC voltage to the target to generate sputter discharge. The material released from the target by the sputter discharge reaches the substrate 9 and a predetermined thin film is formed on the surface of the substrate 9.

When a thin film is formed by plasma enhanced chemical vapor deposition (CVD), a substrate holder and electrodes for forming plasma are provided in the processing chamber 85. An exhaust system for exhausting the inside of the processing chamber 85, a gas introduction system for introducing a source gas into the processing chamber 85, and a high frequency power source for applying a high frequency voltage to the electrodes to generate a high frequency discharge are provided. A gas phase reaction occurs in the source gas in the plasma generated by the high frequency discharge, and a thin film is formed on the surface of the substrate 9. Furthermore, when plasma etching is performed, the structure is almost the same as that of the plasma chemical vapor deposition, but a gas having an etching action such as a fluorine-based gas is introduced into the processing chamber 8591. The surface of the substrate 9 is etched by utilizing the action of active fluorine species generated in plasma.

Next, the overall operation of the substrate processing apparatus of this embodiment having the above configuration will be described. Untreated substrate 9
Are housed in an external cassette 891 placed on the atmosphere side. The unprocessed substrate 9 is transferred from the external cassette 891 into the load lock chamber 87 by the autoloader 892, and is temporarily stored in the in-lock cassette 871.

The transfer robot 10 transfers the unprocessed substrate 9 in accordance with a control signal from the controller 81. That is, the transfer robot 10 includes the arms 31, 32, 41, 4
2, 34, 35, 44, 45 are extended and the upper and lower forks 1 and 2 are sequentially inserted into the load lock chamber 87,
The unprocessed substrate 9 is held and taken out from the in-lock cassette 871. The transfer robot 10 holding the substrate 9 on each of the forks 1 and 2 includes the arms 31, 32, 41, 42, 3
By contracting 4, 35, 44, and 45, the fork centers of the two forks 1 and 2 are both positioned on the robot central axis A.

In this state, as described above, the image pickup device 8
2 is imaged, the arithmetic processing unit 83 performs arithmetic processing, and the determination unit 84 performs determination. As a result, it is determined whether or not the substrate 9 is held at the proper position on the two forks 1 and 2, and if it is determined that the substrate 9 is not held at the proper position, the carrying operation is stopped as a carrying error. Then, the substrate 9 is returned into the load lock chamber 87,
Investigate the cause of the transport error.

When it is determined that the two substrates 9 are held at the proper positions, the transfer robot 10 transfers the substrates 9 one by one to the processing chamber 85. For example, the substrate 9 of the upper fork 2 is transferred to the first processing chamber 85,
After the processing in the processing chamber 85 is completed, the substrate 9 of the lower fork 1 is transferred to the first processing chamber 85. Substrate 9 that has been processed in the first processing chamber 85
Is carried to the next processing chamber 85 while being held by the upper fork 2 and processed.

In this way, while holding the substrate 9 on each of the forks 1 and 2, the substrate 9 is conveyed to each processing chamber 85 in a predetermined order, and the substrate 9 is continuously processed in vacuum. . Then, the substrate 9 that has been processed in the last processing chamber 85 is returned to the external cassette 891 via the load lock chamber 87. Even when returning from the last processing chamber 85 to the load lock chamber 87, the peripheral edge of the substrate 9 is imaged and the substrate 9 is moved to the fork 1.
It may be possible to determine whether or not it is held at an appropriate position above 2.

The substrate processing apparatus of the above embodiment is a cluster tool type apparatus in which a plurality of processing chambers 85 are provided around the transfer chamber 86. The cluster tool type has an advantage that it is easy to increase the number of processing chambers 85 or replace the processing chambers 85 with another one without increasing the occupied area. In this embodiment, the monitoring position is set in the transfer chamber 86, and it is monitored whether the substrate 9 is in the regular position in the transfer chamber 86. Therefore, it is not necessary to separately provide a monitoring chamber. Therefore,
The substrate 9 can be monitored while making use of the advantages of the cluster tool type, and an increase in the area occupied by the device can be suppressed.

In the above embodiments, the substrate holder and the drive system constitute the transfer robot 10, and the transfer robot 10 is of the multi-joint arm type, but the present invention is not limited to this. A single-joint type robot may be used, or a transport mechanism that cannot be called a robot may be configured. Further, in the above description, it is only judged whether the substrate 9 is deviated from the normal position, but it is also possible to obtain the amount of deviation from the normal position.
The deviation amount includes not only the linear deviation of the position of the substrate 9 from the normal position but also the deviation in the rotation direction of the substrate 9.

[0074]

As described above, according to the substrate transfer system of the first aspect of the present invention, it is possible to transfer two or more substrates to a predetermined position while simultaneously holding them, so that the transfer efficiency is improved. high. In addition, since the presence / absence of holding or the position detection can be performed for two or more substrates collectively, the overall efficiency does not significantly decrease. Further, according to the substrate processing apparatus of the second aspect, it is possible to process the substrate while obtaining the above effect, and the productivity is greatly improved. Further, in the substrate processing apparatus according to the third aspect, it is possible to monitor the substrate while taking advantage of the advantage of the cluster tool type, and to suppress an increase in the occupied area of the apparatus.

[Brief description of drawings]

FIG. 1 is a schematic side view of a substrate transfer system according to an embodiment.

FIG. 2 is a front sectional view showing a detailed structure of the transfer robot 10 shown in FIG.

FIG. 3 is a schematic plan view of the transfer robot 10 shown in FIG.

FIG. 4 is a diagram illustrating coordinates of image data.

FIG. 5 is a diagram illustrating an outline of an image processing program.

FIG. 6 is a diagram illustrating a position determination step performed by a determination program.

FIG. 7 is a schematic plan view of an embodiment of the invention of a substrate processing apparatus.

8 is a schematic side sectional view of a transfer chamber 86 in the substrate processing apparatus shown in FIG.

[Explanation of symbols]

10 Transport robot 1 Lower fork as substrate holder 2 Upper fork as substrate holder 31 arms 32 arms 33 Joint 34 Arm 35 arms 36 joints 41 Arm 42 arms 43 Joint 44 arms 45 arms 46 joints 51 Lower back and forth movement mechanism 511 Lower drive shaft 512 Lower drive source 52 Upper and lower movement mechanism 521 Upper drive shaft 522 Upper drive source 53 Braking shaft 6 Rotary motion mechanism 61 rotation drive shaft 62 rotation drive source 71 First vertical movement mechanism 72 Second vertical movement mechanism 81 Control unit 82 Image sensor 83 Image processing unit 84 Judgment section 85 Processing chamber 86 Transport chamber 87 load lock chamber 9 substrates

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Claims (3)

[Claims] 1. A substrate holder for holding two or more substrates,
A substrate transfer system comprising a drive system for driving a substrate holder and capable of transferring two or more substrates to a predetermined position while holding them at the same time. When the control unit located at the monitoring position and the substrate holder are located at the monitoring position,
From the processing results of the image sensor, an image processing unit that processes an image from the image sensor, an image sensor that captures an image of a space assumed to be occupied by the two or more substrates held by the substrate holder, A substrate transfer system, comprising: a determination unit that determines whether each of two or more substrates is located at a predetermined position or is held by the substrate holder. 2. A substrate processing apparatus comprising: a processing chamber for internally performing a predetermined processing on a substrate; and a substrate transfer system for loading an unprocessed substrate into the processing chamber and unloading the processed substrate from the processing chamber. An apparatus, wherein the substrate transfer system includes a substrate holder that holds two or more substrates and a drive system that drives the substrate holder, and transfers two or more substrates to a predetermined position while simultaneously holding them. It is possible to control the drive system to position the substrate holder at a predetermined monitoring position, and when the substrate holder is positioned at the monitoring position,
From the processing results of the image sensor, an image processing unit that processes an image from the image sensor, an image sensor that captures an image of a space assumed to be occupied by the two or more substrates held by the substrate holder, A substrate processing apparatus comprising: a determination unit that determines whether each of two or more substrates is located at a predetermined position or is held by the substrate holder. 3. The substrate holder and the drive system constitute a transfer robot that transfers two or more substrates to a predetermined position while holding them, and a transfer chamber in which the transfer robot is provided is provided. The processing chamber and the load lock chamber are provided around the transfer chamber in an airtight manner, and the predetermined monitoring position is set in the transfer chamber. The substrate processing apparatus described.