JP2001068530A - Substrate processing equipment - Google Patents

Abstract

(57) [Problem] To provide a practical configuration capable of performing control for disposing a substrate at a set arrangement position in an apparatus with sufficiently high accuracy while using a substrate transfer system. An end effector holding a substrate is provided.
Is driven by the driving mechanism 24 to transfer the substrate 9 from the transfer chamber 3 to the processing chamber 1D through the gate valve chamber 5.
When the image is conveyed, the two marks 25 on the end effector 23 and the image of the substrate 9 are captured by the detector 62 composed of an image sensor without stopping the end effector 23, and an image signal is sent to the signal processing unit 8. . The image signal held by the hold circuit 81 is processed by the image processing circuit 82 to calculate the positions of the effector reference point and the substrate reference point.
The position data of the end effector 23 and the position data of the substrate 9 are obtained by comparing the data of the correct position stored in the memory 3 with the arithmetic circuit 84. The control unit 20 operates so as to correct the displacement, and the substrate 9 is positioned at the set arrangement position with high accuracy.

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 for performing a predetermined process on the surface of a substrate, and particularly to such an apparatus, which accurately transfers a substrate to a set position in the apparatus. This is related to a configuration for performing

[0002]

2. Description of the Related Art Semiconductor devices such as various memories and logics are manufactured through many surface treatments for substrates.
As a substrate processing apparatus for performing such a surface treatment, a sputtering apparatus, a chemical vapor deposition (CVD) apparatus, an etching apparatus, and the like are known. A substrate processing apparatus generally includes a processing chamber for performing a predetermined process on a substrate therein, a substrate transport system for loading an unprocessed substrate into the processing chamber, and discharging a processed substrate from the processing chamber, A load lock chamber and the like are provided between the chamber and the atmosphere. The cluster tool type apparatus adopts a layout in which a transfer chamber is provided in the center, and a processing chamber and a load lock chamber are provided for the transfer chamber. The substrate transfer system includes a transfer robot provided in a transfer chamber.
The transfer robot includes an end effector that holds the substrate at the tip of the arm. A cassette capable of storing a predetermined number of unprocessed or processed substrates is provided in the load lock chamber.

[0003]

In the above-described substrate processing apparatus, it is generally necessary to position a substrate at a predetermined position in a processing chamber for performing processing. The reason for this is that the processing is often different depending on the position in the processing chamber, and in order to perform processing with high reproducibility, it is necessary to always arrange the substrate at the same fixed position in the processing chamber. It is. Further, when returning the substrate from the processing chamber to the load lock chamber, it is necessary to correctly return the substrate to a predetermined position of the cassette in the load lock chamber. For example, when the substrate is shifted back to the cassette, the substrate may collide with the wall surface of the cassette and the substrate may be damaged.

In addition, there is also a need for the substrate and end effector to move through the correct transport path. The reason for this is that, if the substrate and the end effector are not moved along the correct transport path, they may collide with a structure in the apparatus and damage the substrate or the end effector, or the collision may shift the substrate. For example, the end effector moves between the processing chamber and the transfer chamber through the opening of the gate valve chamber.To minimize the diffusion of residual gas from the processing chamber into the transfer chamber, the end effector is opened. Is very small. Therefore, if the end effector is displaced from the correct transport path, the substrate and the end effector are likely to be displaced or damaged by hitting the edge of the opening. Also, to improve exhaust efficiency,
The volume of the processing chamber tends to be small, and the substrate is often transported while keeping a very close state to the inner surface of the processing chamber. For this reason, even if the displacement is, for example, about several mm, the substrate may collide with the inner surface of the processing chamber, and the substrate may be further displaced or the substrate may be damaged.

[0005] The placement of a substrate at a position set as a position where a substrate is to be finally placed (hereinafter referred to as a set placement position) is as follows.
Basically, it is performed under the control of the transfer robot. The transfer robot is a mechanism that uses a servo motor in many cases and is numerically controlled by a computer. More specifically, the setting arrangement position input to the computer is determined based on some reference point in the apparatus. Usually, a point on the axis of the transfer robot is determined as a reference point (hereinafter, this point is referred to as a robot origin).

The transfer of the substrate is performed by designating the amount and direction of movement with reference to the robot origin. For example, a case where the transfer is performed from the transfer chamber to the processing chamber will be described. A specific position in the transfer chamber is designated as a position of the substrate when transfer of the substrate is started (hereinafter, referred to as a transfer start position). Designate a specific position as the setting position. Then, the positional relationship between the transfer start position and the set arrangement position is calculated based on the robot origin, and an amount necessary to move from the transfer start position to the set arrangement position is commanded as X, Y, and Z data. .
Then, the transfer robot is driven based on this command.

[0007] The same applies to the case where a substrate is transferred from the load lock chamber to the transfer chamber. A specific position in the cassette in the load lock chamber is designated as a transfer start position on the basis of the robot origin, and a specific position of the transfer chamber is set on the basis of the robot origin, and the description is similarly made on the basis of the robot origin. The positional relationship between the transfer start position and the set arrangement position is obtained, and X, Y, and Z drive command signals are generated, and the transfer robot is driven by this.

As described above, by inputting the data of the set arrangement position of the substrate in the processing chamber to the computer, it is possible to arrange the substrate with extremely high positional accuracy. In addition, returning the substrate to a predetermined position in the load lock chamber, moving the end effector along the correct transfer path, or inputting appropriate data to the computer that controls the transfer robot,
It is possible with high precision.

However, such high-precision substrate transfer is based on the premise that the substrate is originally correctly located at the transfer start position. If the substrate is not correctly positioned at the transfer start position, it is impossible to correctly position the substrate at the set position even with the high precision servo mechanism of the transfer robot. This may occur, for example, if the substrate is not stored in the correct position in the cassette in the load lock chamber and the substrate is displaced in the cassette. In this case, the substrate is displaced from the set position in the transfer chamber, and is displaced from the set position in the processing chamber.

Although the transfer robot has high precision in terms of electronic control, it is unavoidable that the precision of the transfer robot decreases with time in the mechanical part. For example, a buffer portion such as a bearing used for a mechanical portion may be worn over time, and even though the data may be correct, the substrate may actually be located at a slightly shifted position.

Further, as a cause of the substrate not being properly arranged at the set arrangement position, the substrate may be shifted on the end effector of the transfer robot. The end effector holds the substrate placed on the upper surface. Recently, however, many end effectors have a configuration in which the substrate is held in point contact with the back surface of the substrate at several points. The reason for this is to suppress the generation of particles (general term for fine particles that contaminate the substrate) caused by reducing the contact area with the rear surface of the substrate and damaging the rear surface of the substrate. When the contact area with the back surface of the substrate is reduced in this way, the possibility that the substrate slips on the end effector and shifts the position is increased. When the processing in the processing chamber is a film forming process and a predetermined thin film is formed on the surface of the substrate, the substrate after the film formation may be slightly distorted. This is because the thin film is deposited with internal stress, and the distorted substrate is liable to slip on the end effector and cause misalignment. If the substrate is displaced on the end effector in this way, even if the end effector is moved correctly by numerical control, the substrate will not be placed at the correct position in the processing chamber or will not be returned to the correct collection position of the cassette. There is a problem to do.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a practical use in which control for arranging a substrate at a set arrangement position in an apparatus can be performed with sufficiently high accuracy while using a substrate transport system. It is meaningful to provide a unique configuration.

[0013]

According to a first aspect of the present invention, there is provided a process chamber for performing a predetermined process on a substrate, and an unprocessed substrate in the process chamber. A substrate processing apparatus comprising: a substrate transport system for loading and unloading a processed substrate from a processing chamber, the substrate transport system having an end effector for holding a substrate and a driving mechanism for driving the end effector. In addition, the end effector is provided with at least two marks, a detector that detects these marks or these marks and the substrate at the same time, and a signal from the detector to process the position of the end effector with respect to the correct position. A signal processing unit for determining the displacement and / or the displacement of the substrate with respect to the correct position. In order to solve the above-mentioned problem, the invention according to claim 2 of the present application provides a plurality of vacuum chambers including a processing chamber for performing a predetermined process on a substrate inside a gate valve chamber in which a gate valve is provided. A substrate processing apparatus having a substrate transport system that is airtightly connected while interposed, and carries an unprocessed substrate into the processing chamber and unloads the processed substrate from the processing chamber to another vacuum chamber. The substrate transport system has an end effector that holds the substrate and at least one mark is provided, and a driving mechanism that drives the end effector, and a detector that detects the end effector mark or the substrate, and a detector Signal of the end effector in the gate valve chamber relative to the correct position and / or the gate valve of the substrate. A signal processing unit for determining the deviation of the position with respect to the correct position in the chamber is provided,
Further, the detector is configured to detect a mark or a substrate when the end effector passes through or stops in the gate valve chamber. In order to solve the above-mentioned problems, the invention according to claim 3 of the present application provides a processing chamber in which a predetermined processing is performed on a substrate, an unprocessed substrate loaded into the processing chamber, and a processed substrate processed. A substrate processing apparatus comprising: a substrate transport system that unloads from a chamber, the substrate transport system having an end effector that holds a substrate and is provided with at least one mark, and a driving mechanism that drives the end effector. A detector for detecting a mark or a substrate of the end effector, and a signal processing unit for processing a signal from the detector to determine a positional deviation with respect to a correct position of the end effector and / or a positional deviation with respect to a correct position of the substrate. Provided, and the detector further comprises:
An image sensor for capturing an image including a mark or a substrate, wherein the image sensor is configured to hold the captured image under predetermined conditions while moving an end effector and output the image to a signal processing unit. To solve the above problems,
The invention described in claim 4 of the present application is the invention described in claim 1, 2 or 3 above.
In the configuration, the correct position is such that the substrate is transferred from a transfer start position, which is a position of the substrate when starting transfer of the substrate, to a set arrangement position that is finally set as a position where the substrate should be arranged. When the end effector moves,
The end effector or the substrate is located at a position where the substrate is taken during the transfer. In order to solve the above-mentioned problem, the invention according to claim 5 of the present application is characterized in that, in the configuration according to claim 4, the signal processing unit includes: a reference memory in which the data at the correct position is stored; An operation circuit for comparing the data of the detected position of the end effector or the substrate with the data of the correct position to obtain a position shift, and the reference memory includes the end effector or the substrate or the substrate jig. After the substrate or the substrate jig is returned to the transfer start position after the substrate or the substrate jig is actually correctly arranged at the set arrangement position, data obtained by detecting the position taken by the end effector or the substrate or the substrate jig by the detector is stored. It has a configuration that it can be updated. In order to solve the above-mentioned problem, the invention according to claim 6 of the present application, in the configuration according to claim 4 or 5, wherein a plurality of the transfer start positions and the set arrangement positions are set and set from the transfer start positions. A configuration is provided in which a plurality of the detectors are provided so that a positional deviation from the correct position can be obtained during each conveyance to the arrangement position. In order to solve the above-mentioned problem, the invention described in claim 7 of the present application is directed to claim 1, 2, 3, 4, 5, or 6 of the present invention.
In the above configuration, the driving mechanism of the substrate transfer system drives the end effector so as to correct the determined positional deviation.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a schematic plan view showing an embodiment of the substrate processing apparatus of the present invention, and FIG. 2 is a schematic sectional view taken along line XX of FIG. The substrate processing apparatus shown in FIGS.
It is a cluster tool type device, and includes a transfer chamber 3 disposed at the center and a plurality of processing chambers 1A, 1B, 1C, 1D, 1 provided around the transfer chamber 3.
E, 1F (hereinafter, collectively referred to as processing chamber 1 as necessary) and two load lock chambers 4. Each chamber 1
A, 1B, 1C, 1D, 1E, 1F, 3, 4 are vacuum vessels evacuated by a dedicated or shared exhaust system 100. For each transfer chamber 3 in the center,
A, 1B, 1C, 1D, 1E, 1F, and 4 are air-tightly connected, and the connection point has a gate valve 51 inside.
The gate valve chamber 5 provided with is provided.

The transfer chamber 3 is provided with each processing chamber 1
A, 1B, 1C, 1D, 1E, and 1F are air-tightly separated from each other to prevent cross-contamination of the internal atmosphere, and to the processing chambers 1A, 1B, 1C, 1D, 1E, 1F and the load lock chamber 4. This is a space through which the substrate is transported. A transfer robot 21 constituting a substrate transfer system is provided in the transfer chamber 3. The transfer robot 21 takes out the substrates 9 one by one from one of the load lock chambers 4 and takes out each of the processing chambers 1A, 1B, 1
The data is sent to C, 1D, 1E, and 1F for sequential processing. Then, after the last processing is completed, it is returned to one or the other load lock chamber 4.

In this embodiment, the transfer robot 21
Includes an end effector 23 provided at the tip of the arm 22 to hold the substrate 9, and a drive mechanism 24 for driving the end effector 23. The driving mechanism 24
The end effector 23 can be provided with a rotational motion about a vertical axis passing through the center of the transfer chamber 3, a linear motion in any radial direction of a circle about the axis, and a linear motion in the vertical direction. It is configured to be able to. Further, a control unit 20 for controlling the entire apparatus including the substrate transfer system is provided.

The major feature of this embodiment is that when the substrate 9 is transported by the above-described substrate transport system, the substrate 9
Is that the positions of the end effector 23 and the substrate 9 are detected during the conveyance so that the position of the end effector 23 is correctly arranged at the set arrangement position. More specifically, the transfer chamber 3
And processing chambers 1A, 1B, 1C, 1D, 1E, 1F
When passing through the gate valve chamber 5 provided between the end effector 23 and the like, it is determined whether or not the positions of the end effector 23 and the substrate 9 are correct. Based on the result, the substrate transport system is controlled and the substrate 9 is set and arranged. Make sure that they are correctly positioned.

Another major feature of this embodiment is that
The two marks 25 are provided on the end effector 23, and the positions of the end effector 23 and the substrate 9 are detected by detecting the marks 25. Hereinafter, the configuration of the mark detection system 6 that detects the mark 25 of the end effector 23 will be described with reference to FIGS. FIG. 3 is a schematic plan view of the end effector 23 used in the apparatus shown in FIGS. FIG. 4 is a front sectional view showing a schematic configuration of the mark detection system 6 for detecting the mark 25 shown in FIG.

As shown in FIGS. 1 and 2, the end effector 23 is a plate-like member fixed to the tip of the arm 22 of the transfer robot 21. This end effector 23
Has a U-shaped notch in a substantially rectangular plate as shown in FIG. End effector 2
The depth direction of the U-shaped notch 3 corresponds to the direction of the long side of the rectangle. When performing the linear motion in the radial direction, the end effector 23 moves while maintaining a posture in which the depth direction of the U-shaped notch coincides with the direction of the linear motion. Hereinafter, a virtual line extending in the depth direction of the notch at the surface of the end effector 23 is referred to as "effector reference line" in FIG. 3 shown by L _{E S.}

As shown in FIG. 3, two marks 25 formed in a black circular pattern are provided on the surface of the end effector 23. The mark 25 can be provided by an arbitrary method such as painting, vapor deposition, or spraying. The two marks 25, the line segment connecting their centers is provided so as to be bisected by the effector reference line L _ES with orthogonal to effector reference line L _ES. 1 and 3, the substrate 9 is placed and held so as to substantially cover the U-shaped cutout of the end effector 23. Projections (not shown) are provided at several places around the U-shaped notch, and the back surface of the substrate 9 comes into contact with these projections. The position where the mark 25 is provided is a position sufficiently distant from the area where the substrate 9 is placed, so that the mark 25 is not covered by the substrate 9.

As shown in FIG. 2, the gate valve chamber 5 is
Adjacent chambers 1A, 1B, 1C, 1D, 1E, 1
A vacuum vessel airtightly connected to F, 3, 4;
The gas is exhausted by a dual or exclusive exhaust system 100. Then, the gate valve 51 is driven in the gate valve chamber 5, and the processing chambers 1A, 1B, 1
The opening 54 provided on C, 1D, 1E, 1F or the load lock chamber 4 side is opened and closed.

Specifically, the gate valve 51 is fixed to a tip of a driving rod 53 connected to a driving source 52.
When the drive source 52 operates, the drive rod 53 is driven, the gate valve 51 moves up and down, and the processing chambers 1A, 1
An opening 54 provided on the side of B, 1C, 1D, 1E, 1F or the load lock chamber 4 is opened and closed. As shown in FIGS. 2 and 4, a detection opening 55 is provided in the upper wall of the gate valve chamber 5, and the mark detection window 56 is closed so as to close the detection opening 55.
Is filled. A vacuum seal such as an O-ring is provided between the mark detection window 56 and the upper wall.

The mark detection system 6 includes an illumination light source 61 for illuminating the inside of the gate valve chamber 5 through the mark detection window 56.
And the gate valve chamber 5 illuminated by the illumination light source 61
And a detector 62 that captures an image inside the image through the mark detection window 56. Above the mark detection window 56, a half mirror 63 is provided at an angle of 45 degrees. As the illumination light source 61, a small, high-luminance halogen lamp or the like is suitably used. The illumination light source 61 includes a cup-shaped reflector 611, and emits light forward. The emitted light is reflected by the half mirror 63, reaches the gate valve chamber 5 through the mark detection window 56, and illuminates the gate valve chamber 5.

A diffusion plate 64 is provided between the illumination light source 61 and the half mirror 63. The diffusion plate 64
By diffusing the light from the illumination light source 61, it is prevented that the illumination light source 61 is strongly illuminated by the pattern of the light emitting portion such as the filament. Above the half mirror 63, a total reflection mirror 65 is provided. The total reflection mirror 65 is provided at an angle of 45 degrees opposite to the half mirror 63. The detector 62 is an area image sensor provided with a CCD 621, and is, for example, STC-400 manufactured by Sensor Technology Co., Ltd. The light receiving surface of the CCD 621 is provided so as to intersect perpendicularly with an optical axis which is bent 90 degrees by the total reflection mirror 65 and extends horizontally.
The detector 62 includes an optical system 622 that projects an image on the light receiving surface of the CCD 621.

The image in the gate valve chamber 5 illuminated by the illumination light source 61 is picked up by the CCD 621 via the half mirror 63 and the total reflection mirror 65. Therefore, as shown in FIG. 4, when the end effector 23 holding the substrate 9 reaches the inside of the gate valve chamber 5, the images of the substrate 9 and the end effector 23 are transferred to the CCD 621.
Is imaged. Thereby, the end effector 2
3 are detected.

The mark detection system 6 detects the position of the end effector 23 and the substrate 9 in the horizontal plane by detecting the mark 25. Another major feature of the present embodiment is that a vertical direction detection system 7 for detecting the vertical position of the end effector 23 and the substrate 9 is provided. This will be described with reference to FIG. FIG. 5 is a schematic front sectional view illustrating the configuration of the vertical direction detection system 7 provided in the apparatus of the present embodiment.

The vertical direction detection system 7, like the mark detection system 6, detects when the end effector 23 reaches the inside of the gate valve chamber 5. A vertical detection window 57 is provided on the upper wall of the gate valve chamber 5 in addition to the mark detection window 56. Vertical detection window 57
This is an optical window for hermetically closing an opening provided in the upper wall. The vertical direction detection system 7 has the same configuration as the laser displacement meter. That is, the vertical direction detection system 7 is connected to the end effector 23 of the gate valve chamber 5 through the vertical direction detection window 57.
Alternatively, a laser light source 71 for causing a laser beam to enter the substrate 9
A light receiver 72 for receiving the laser light reflected back from the end effector 23 or the substrate 9, and a vertical signal for processing a signal from the light receiver 72 to detect a vertical displacement of the end effector 23. It mainly comprises a processing unit 73.

As the laser light source 71, a semiconductor laser, a He-Ne laser, or the like can be used. Laser light source 71
The optical axis of the laser light entering the gate valve chamber 5 from above is slightly inclined from the vertical direction as shown in FIG. The laser light reflected on the end effector 23 or the substrate 9 is emitted at the same angle as the incident angle, and is incident on the light receiver 72. At this time, the incident position of the laser beam on the light receiver 72 changes as the end effector 23 or the substrate 9 is displaced in the vertical direction, as shown in FIG. As the light receiver 72, a photodiode array, a CCD, or the like is used.

Then, the height of the transfer line is correctly adjusted for the substrate 9.
The incident position of the laser light reflected on the end effector 23 or the substrate 9 when is transported is set as a reference position. The vertical signal processing unit 73 processes the signal from the light receiver 72 to determine at which position the laser light is incident, thereby detecting the position of the end effector 23 or the substrate 9 in the vertical direction. It has become.
A signal is continuously sent from the light receiver 72 to the vertical signal processing unit 73 continuously in time. However, in the present embodiment, the displacement is detected based on a signal at the moment when the signal is held by a hold circuit 62 described later. Has become. Since the height of the end effector 23 and the height of the substrate 9 differ only by the amount of the protrusion, the position of the end effector 23 is directly detected, and the position of the substrate 9 is detected indirectly. You may.

FIG. 6 is a schematic plan view illustrating the positional relationship between the mark detection system 6 and the vertical direction detection system 7. As shown in FIG. 6, the correct path the end effector 23 to be taken during transport (hereinafter, the transport line) L _T, is set so as to pass through the gate valve chamber 5. Movement of the end effector 23 on the conveying line L _T through the gate valve chamber 5 is a linear motion in the radial direction as described above, the end effector 23 is conveying line L while matching the effector reference line L _ES the transport line L _T and moves along the _T, as can be seen from FIG. 6, the mark detection window 56 just above the conveying line L _T are located. Vertical detection window 57 is located obliquely above the conveying line L _T.
However, the distance between the vertical direction detection window 57 and the mark detection window 56 is sufficiently shorter than の of the width (length in the short side direction) of the end effector 23, and the position immediately below the vertical direction detection window 57. Does not come off the end effector 23.

Next, the configuration of the signal processing unit 8 that processes signals from the mark detection system 6 and the vertical direction detection system 7 will be described. A first basic function of the signal processing unit 8 is to process signals from the mark detection system 6 and the vertical direction detection system 7 to obtain the position of the end effector 23 and the position of the substrate 9 in the gate valve chamber 5. That is. The position in the gate valve chamber 5 means the gate valve chamber 5
Is a relative position based on a reference position (hereinafter referred to as a gate valve chamber reference position). The position of the end effector 23 is actually the position of a point serving as a specific reference of the end effector 23 (hereinafter referred to as an effector reference point), and the position of the substrate 9 is referred to as the specific position of the substrate 9. This is the position of a reference point (hereinafter referred to as a substrate reference point).

In this embodiment, the position is detected while the end effector 23 is moved without stopping in the gate valve chamber 5. Therefore, the position in the gate valve chamber 5 is not the stop position.
The image signal sent from the CCD 621 of the detector 62 is an image of the moving end effector 23 and the substrate 9, that is, a moving image. The signal processing section 8 always extracts an image from the moving image under the same conditions, and performs signal processing on the image to obtain the positions of the effector reference point and the substrate reference point. More specifically, as shown in FIG. 2, the signal processing unit 8 includes a hold circuit 81 that holds an image signal sent from the mark detection system 6 when a certain condition is satisfied,
An image processing circuit 82 for processing the image signal held by the hold circuit 81.

The hold circuit 81 includes a hold memory 8
11 and a decision circuit 812. A signal from the CCD 621 is sent to the hold memory 811. The signal from the CCD 621 is C
This is a read signal of the accumulated charge of each pixel of the CD 621, and is an image signal sent one frame at a time in a predetermined read cycle. The hold memory 811 updates and stores the image signal in each read cycle.

The judgment circuit 812 includes the hold memory 81
The image signal of one frame stored in 1 is read out, and the following judgment is made. Judgment circuit 81
2 will be described with reference to FIGS. 7, 8, and 9. FIG. FIGS. 7, 8, and 9 are diagrams illustrating the determination performed by the determination circuit 812 included in the hold circuit 81. 7 illustrates a hold position set in a space in the gate valve chamber 5, and FIG.
FIG. 9 is a view showing a reference pixel row defined on the CCD 621 in relation to the hold position shown in FIG. 7, and FIG. 9 is a view for explaining a hold condition.

The judgment circuit 812 is provided for the end effector 23
It is determined whether or not the mark 25 has reached the hold position. Hold position is gate valve chamber 5
It is set to a predetermined position on the transport line L _T of the inner. Specifically, as shown in FIG. 7, the transport line L _T
Either mark 25 is in contact with the position of the conveying line L _T horizontally perpendicular to the hold-line L _H to the end effector 23 at a predetermined point above is the hold position.

On the light receiving surface of the CCD 621, a position related to the above-mentioned hold position is selected. Specifically, among the pixels constituting the light receiving surface of the CCD621, pixels located on the line where the hold line L _H is just projected, (shown in FIG. 8 P-P) the reference pixel string Has been selected. The CCD 62
Each pixel of one is arranged along two directions (hereinafter, X direction and Y direction) perpendicular to each other in the plane.
The reference pixel row PP is selected, for example, for a pixel row arranged in the X direction. Each pixel column is
As shown in FIG. 8, P ₁₁ , P ₁₂ ,... P _1n , P ₂₁ , P ₂₂ ,
_{... P 2n, ...... P m1,} P m2, ... When P _mn, P _s1,
P _s2, ... P _sm is selected as the reference pixel columns P-P.

The CCD 621 has a hold line L
With reference pixel columns P-P to the position of the image point _H is located, intersection of the conveying line L _T and the hold line L _H is, the center of the reference pixel columns P-P pixels (hereinafter, the reference pixels) Is mounted to the gate valve chamber 5 with high precision so as to correspond to the position of. still,
Intersection of the conveying line L _T and the hold line L _H is a point to be a reference for identifying the position of the gate valve chamber 5, in the gate valve chamber reference position (Fig. 7 described above,
It is shown by the S _G).

The determination operation of the determination circuit 812 will be described with reference to FIG.
This will be described in more detail with reference to FIG. (1)-of FIG.
(3), an image signal for each frame that is sent to the hold memory 811 indicates respectively, shows how the end effector 23 holding the substrate 9 is moved along the transport line L _T. When the end effector 23 moves, the image signal changes as shown in FIGS. 9 (1) to 9 (3). Then, as shown in FIG. 9C, an image signal when one of the marks 25 of the end effector 23 is captured by any of the pixels on the reference pixel row PP is held. I have.

More specifically, for example, mark 2
When 5 is black and the surface of the end effector 23 is white or the like, when the mark 25 is captured, the accumulated charge of the pixel temporarily decreases. Therefore, when the magnitude of the readout signal for one of the pixels forming the reference pixel row PP becomes smaller than a certain value, the determination circuit 812 determines that the image signal of one frame at that time should be held as the image signal to be held. to decide. When the image signal is held, the data in the hold memory 811 is not updated, and the held image signal is sent to the image processing circuit 82 as it is.

Next, the configuration of the image processing circuit 82 will be described. The image processing circuit 82 obtains the positions of the effector reference point and the substrate reference point at the moment of the hold from the image signal held by the hold circuit 81. The image processing performed by the image processing circuit 82 will be described with reference to FIGS. FIGS. 10 and 11 are diagrams illustrating the image processing performed by the image processing circuit 82. FIG.

First, a configuration for obtaining an effector reference point will be described.
Will be described. In the present embodiment, the effector reference point is
Set at the midpoint of the line connecting the centers of each of the two marks 25
Have been. Therefore, the image processing circuit 82 first
10 (in FIG. 10, M _c1, M_c2)
An operation is performed. For example, held
Pixel group capturing mark 25 in image signal
Are specified respectively. And each of those pixel groups
In each case, for example, the pixel located at the most + side in the Y direction
Pixel located halfway between the pixel located on the
Identify the cell. Similarly in the X direction,
Exactly halfway between the pixel and the most negative pixel
Identify the pixel. These two pixels are in principle
Matches, but if they do not match, connect them
Identify the pixel located at the midpoint of the line segment. in this way
The pixel specified as a result is the center M of the mark 25._c1, M
_c2Is the pixel that captures

A group of pixels capturing each mark 25 is specified, and two pixels capturing the centers M _c1 and M _c2 of each mark 25 are specified from the pixel group. Then, the pixel located at the midpoint of the line segment connecting the centers M _c1 and M _c2 of the two marks 25 is the pixel capturing the effector reference point. The position of the pixel capturing the effector reference point is the origin of coordinates when obtaining the substrate reference point described below. Hereinafter, this pixel is referred to as the image origin (I _O in FIGS. 10 and 11). Shown).

In the present embodiment, the center of the substrate 9 (indicated by C in FIGS. 10 and 11) is set as the substrate reference point. To determine the center C of the substrate 9 as a substrate reference point,
First, as shown in FIGS. 10 and 11, the distance from the centers M _c1 and M _c2 of the marks 25 to the group of pixels capturing the substrate 9 is determined. Specifically, the centers M _c1 , M
_{Tracing in the} X direction from _{c2, the} first pixel capturing the substrate 9 is specified. Note that the end effector 23 is white, and the substrate 9 is, for example, a semiconductor wafer and has a color (for example, silver) that forms a sufficient contrast with white. The pixels specified in this manner are set as edge points E ₁ and E ₂ . And the center M of the mark 25
determining _c1, M _c2 and the edge point E _1, the distance between E _2, respectively. The obtained distances are assumed to be D ₁ and D ₂ . Note that the distance here directly refers to the number of pixels.
The actual distance can also be converted from the magnification of 2 or the like (the same applies hereinafter).

Here, as shown in FIG. 10, D ₁ = D ₂
, The center C of the substrate 9 exists on the X axis centered on the image origin I _O. Therefore, the distance from the image origin I _O to the pixel that initially captures the substrate 9 is D
Let ₃ be the radius of the substrate 9 (value converted by the number of pixels) as r
Then, a pixel located on the + side on the X axis and located at the coordinates of (D ₃ + r) captures the center C of the substrate 9. In this case, the image processing circuit 82 calculates the calculated coordinates (D ₃ + r, 0) of the pixel as data of the substrate reference point.

Next, as shown in FIG.₁ ≠ D_Two so
In some cases, the simple calculation as described above requires the center C of the substrate 9
Is not obtained, and is performed as follows. First, in FIG.
And two edge points E₁, E₂The midpoint of the line connecting
E _M Then E_M Is I_O Through M₁E₁, And M_TwoE
₂On a line (X-axis) parallel to. Also, the center C of the substrate 9
From E₁, E_M, E_TwoAnd draw a line to_M
 Is ∠E₁CE_ThreeIs a line segment bisecting. And I_O
 M₁Length (= I_O M_TwoWhere m is the length of the line segment
E₁E₂From the Pythagorean theorem, the length of₁E₂= 4m^Two+ (D₁-D_Two )^Two｝ ... Equation (1) Also, CE_MThe length of CE_M = √ ｛r^Two− (E₁E₂)^Two / 4} = {[r^Two-｛4m^Two+ (D₁-D_Two )^Two｝ / 4] Expression (2) is obtained.

Here, the intersection of the perpendicular drawn from E _{2 with} respect to the line segment connecting M ₁ and E _{1 is} assumed to be A, and the intersection of the perpendicular drawn from the center C to the X axis is assumed to be B. △ E ₁ AE ₃ and △ CBE _M
From similar, the _{E M B = CE M × (} E 1 E 2 / 2m) ... Equation _{(3) BC = CE M ×} {E 1 E 2 / (D 1 -D 2)} ... Equation (4) . Therefore, the coordinates of the center C of the substrate 9 are represented by (X _C , Y
When _C), X _C = (represented by _{D 1 -D 2) / 2 +} E M B Y C = BC, they, by substituting equation (1) ~ (4), m, D 1, D ₂ , r. Since m and r are constants, after all, as described above,
By obtaining D ₁ and D ₂ , the coordinates of the center C of the substrate 9 can also be obtained.

As described above, the image processing circuit 82 processes the image signal from the hold circuit 81 to obtain a pixel capturing the effector reference point and a pixel capturing the substrate reference point. . Image processing circuit 8
Reference numeral 2 includes a microcomputer having a RAM, a ROM, an input / output circuit, and the like, and executes a program for performing the above-described operation. In the example described above, the center C of the substrate is obtained as the substrate reference point, but other cases may be used. For example, an orientation flat or a notch (small cutout) formed on the periphery of the substrate may be used as the substrate reference point.

The second basic function of the signal processing unit 8 is to determine how much the position of the end effector 23 and the substrate 9 in the gate valve chamber 5 determined as described above is shifted from the correct position. That is. That is, the signal processing unit 8 includes a reference memory 83 storing data of a correct position in the gate valve chamber 5 and a reference memory 83.
And an arithmetic circuit 84 for calculating the position shift of the end effector 23 and the position shift of the substrate 9 in comparison with the above data.

First, the output of the image processing section 82 is input to the reference memory 83 by the switch circuit 85,
Whether the signal is input to one input of the arithmetic circuit 84 is selected. The switch circuit 85 inputs the output of the image processing circuit 82 to the reference memory 83 at the time of teaching, which will be described later, and inputs the output to the arithmetic circuit 84 at the time of actual conveyance of the substrate 9.

The reference memory 83 is a DRAM or SRA
It is a rewritable memory such as M. Reference memory 83
As described above, data of the correct positions of the effector reference point and the substrate reference point are input in advance. The data at the correct position is created by a teaching operation and stored in the reference memory 83. Hereinafter, this teaching will be described.

In the teaching, in order for the end effector 23 and the substrate 9 to be properly arranged at the set arrangement position from the transfer start position, the position of the effector reference point or the substrate reference point when passing through the gate valve chamber 5 is determined. This is the work of determining data to be taken (hereinafter, teaching data). In this work, after the end effector 23 and the substrate 9 are correctly arranged by hand at the set arrangement position, the transfer robot 21 is operated and returned to the transfer start position by an operation reverse to the operation of transferring to the set arrangement position. I do. At this time, the positions of the end effector 23 and the substrate 9 are detected by the mark detection system 6 and the vertical direction detection system 7, and teaching data is obtained based on the image signal held under essentially the same conditions. .

First, the arrangement at the set arrangement position by manual operation will be described. FIG. 12 is a diagram illustrating the arrangement at the set arrangement position by manual operation. In the following description, as an example, a case where the set arrangement position is within the processing chamber 1D will be described. The set arrangement position is a position above the substrate holder 11 in the processing chamber 1D. More precisely, it is on a vertical line passing through the center of the substrate holding surface of the substrate holder 11 and at a position above the substrate holding surface by a predetermined distance.

Incidentally, this set arrangement position is, as described above,
Robot origin of the transfer robot 21 (indicated by O in FIG. 2)
Are set as coordinates with reference to. The robot origin O is a point on the center axis of the transfer robot 21 as shown in FIG. Based on this operation origin, (X, Y,
The set arrangement position is set at the coordinates of Z). Teaching is performed in the following procedure. First, a jig (hereinafter, holder jig) 91 as shown in FIG. This holder jig 91 is a trapezoidal member having a height obtained by subtracting the thickness of the end effector 23 from the height from the substrate holding surface of the substrate holder 11 to the set arrangement position. Further, a mark 111 is formed so that the center axis of the holder jig 91 and the center axis of the substrate holder 11 can be aligned with each other.
The holder jig 91 is arranged coaxially with respect to the substrate holder 11 by using 1.

Next, the holder jig 9 is moved so that a predetermined point on the upper surface of the end effector 23 coincides with the set arrangement position.
The end effector 23 is manually placed on 1.
Specifically, for example, in the upper surface of the end effector 23, U
The end effector 23 is arranged so that the center point of the arc portion of the character-shaped notch coincides with the set arrangement position. A mark 911 is provided on the upper surface of the holder jig 91 so that the end effector 23 can be arranged at such a position.

Then, on this end effector 23,
A jig (hereinafter, a substrate jig) 92 made of a plate material having the same dimensions and shape as the substrate 9 is arranged. At this time, the center of the substrate jig 92 (more precisely, the center of the back surface of the substrate jig 92) is located at the set arrangement position, that is, the center axis of the substrate jig 92 and the center axis of the substrate holder 11 are aligned. To match. For this positioning, for example, a laser can be used. That is, a small hole is formed in the center of the substrate jig 92, and a hole is also formed in the holder jig 91 through the central axis. The laser is incident from above the substrate holder 11 along the central axis of the substrate holder 11. If the center of the substrate jig 92 is aligned with the center axis of the substrate holder 11, the laser is applied to the hole of the substrate jig 92 and the holder jig 91.
And returns to the surface of the substrate holder 11 after being reflected.

In this manner, the holder jig 91, the end effector 23, and the substrate jig 92 are positioned so that a predetermined point on the upper surface of the end effector 23 and the center of the back surface of the substrate jig 92 are located at the set arrangement positions. Is placed manually.
Next, an operation signal is sent to the transfer robot 21 to move the end effector 23 to a transfer start position set in the transfer chamber 3. This movement is completely opposite to the movement at the time of the actual transfer of the substrate 9.

When the end effector 23 holding the substrate jig 92 moves in the reverse direction from the set arrangement position to the transfer start position, the mark detection system 6 and the vertical direction detection system 7
Is operated to detect the position of the mark 25 of the end effector 23 and the position of the substrate jig 92 in the gate valve chamber 5.
That is, the image is held under essentially the same conditions as described above, and the position of the effector reference point and the position of the substrate reference point are specified from the held image. Since the movement direction of the end effector 23 is opposite to that in the case described above, the hold timing is determined by the mark 25 when the reference pixel row P−
This is the timing of passing through P. That is, it is held at the timing when the accumulated charge temporarily increased by catching the mark 25 decreases to the original amount.

As described above, the position of the effector reference point and the position of the substrate reference point are directly specified by the position of the pixel on the light receiving surface of the CCD 621. However, the reference pixel and the reference position S _{G of the} gate valve chamber are set so that the reference pixel corresponds to the reference position S _{G of the} gate valve chamber.
The CCD 621 is mounted with high accuracy (so that the image point becomes the reference point), so that the position of the effector reference point or the substrate reference point is specified based on the reference position of the gate valve chamber. That is, in the hold timing, effector reference point and the substrate reference point is specified that it is in any position with respect to the gate valve chamber reference position S _G.

The vertical position of the effector reference point is detected by the vertical direction detection system 7 as described above. Although the vertical direction detection system 7 does not always detect the vertical position of the effector reference point itself, the end effector 23 moves while maintaining a horizontal posture with high accuracy, and the upper surface of the end effector 23 has no inclination. Good as things. Therefore, the vertical position at a point other than the effector reference point is defined as the vertical position of the effector reference point. The vertical position of the substrate reference point may be a value obtained by adding the height of the protrusion of the end effector 23 to the vertical position of the effector reference point. The data of the positions of the effector reference point and the substrate reference point specified in this manner are:
The data is sent to the reference memory 83 and stored. Thus, a series of teaching operations is completed.

Next, a description will be given of the detection of the positional shift of the end effector 23 and the positional shift of the substrate 9 in the actual transport of the substrate 9, and the transport of the substrate 9 with the corrected offset. In the following description, a case where the substrate 9 is transferred from the transfer chamber 3 to the processing chamber 1D will be described as an example. FIG. 13 is a diagram illustrating the transfer of the substrate 9 with the displacement corrected.

The transfer robot 21 is provided as shown in FIG.
The transfer start position P set in the transfer chamber 3_S 
From the set arrangement position P in the processing chamber 1D_E Conveyed to
The end effector 23 is moved. Transfer robot
Unit 21 has a coordinate system based on the robot origin O.
And the transfer start position P_S And the setting arrangement position P_E And position
A drive command signal according to the relationship is sent. That is, the robot
In the coordinate system where the origin O is (0,0,0),
Start position P_S To (X₀ , Y₀ , Z₀ ), And the setting position
P_E To (X₁ , Y₁ , Z₁ ), The control unit 20
If the substrate reference point is (X ₀ , Y₀ , Z₀ ) To (X₁ , Y₁ ,
Z₁ ) To drive the transfer robot 21 to move to
Send. That is, the drive command signal is (X₁ -X₀ , Y₁ −
Y₀ , Z₁-Z₀ ) Just move the end effector 23
Signal.

[0062] In FIG. 13, dashed line is the locus of the substrate reference point when the substrate 9 is conveyed correctly corresponds to the conveying line L _T. Further, the two-dot chain line in FIG. 13, not originally substrate 9 is located in the transport start position P _S,
This shows the locus of the substrate reference point when the substrate is not correctly transported due to this. The transfer robot 21 operates based on the drive command signal, and as described above, the end effector 23
Passes through the gate valve chamber 5, and images of the end effector 23 and the substrate 9 are taken by the CCD 621. Then, an image is held at the timing described above, from the hold images, relatively more positional relationship between the gate valve chamber reference position S _G, the position of the effector reference point and the substrate reference points are determined.

Then, the actual substrate transfer obtained as described above is performed.
The position data at the time of sending (hereinafter referred to as actual data)
Compare with teaching data stored in memory 83
You. In other words, teaching and actual
And compare the data to determine the difference. In other words, the substrate
Teaching data P of reference point_TTo (X_TS, Y_TS, Z_TS)
And the actual data P_RTo (X_RS, Y_RS, Z_RS)
And the arithmetic circuit 84 calculates (X_TS-X_RS, Y_TS-Y_RS, Z_TS
-Z_RS) Correction vector V_C Ask for. And
Kuturu V_C If each component of is less than a predetermined size, the substrate
The reference point is determined to be a correct position. Also one of
If the component exceeds the specified size,
Then, assuming that the substrate 9 is not properly arranged at the set arrangement position,
Emit a correction signal. This correction signal is obtained by
Regular vector V_C (X_TS-X_RS, Y _TS-Y_RS, Z_TS-Z
_RS) And the opposite sign, ie, (X
_RS-X_TS, Y_RS-Y_TS, Z_RS-Z_TS).

The correction signal is sent to the control section 20. The control unit 20 controls the transfer robot 21 according to the correction signal, and correctly positions the substrate 9 at the set arrangement position. That is,
After the movement of the end effector 23 by the above-described drive signal is completed, the transfer robot 21 moves the end effector 2
3 is further moved by the amount of the correction signal. As a result, the substrate 9 is correctly positioned at the set arrangement position. It should be noted that the displacement in the vertical direction occurs less frequently and less frequently than the displacement in the horizontal direction. Therefore, the detection and correction of the vertical displacement may not be normally performed, but may be performed once during a predetermined operation time (for example, 24 hours) of the apparatus.

The teaching data for the effector reference point is compared with the actual data. Then, it is confirmed that the difference is equal to or less than a predetermined value.
If the difference between the teaching at the effector reference point and the actual data is larger than a predetermined value, it indicates that an error due to a mechanical system such as wear has increased. Therefore, in this case, a maintenance required signal indicating that maintenance work such as inspection and maintenance is required is issued. The maintenance required signal is displayed on a display unit (not shown) provided in the apparatus. The difference between the teaching data and the actual data for the board reference point (that is, the displacement of the board 9) may be caused by the board 9 being displaced on the end effector 23 in some cases. The misalignment of the end effector 23 itself as described above may be included in the cause.

In the above description, the detection and the correction of the displacement during the transfer from the transfer chamber 3 to the processing chamber 1D have been described, but the detection of the displacement during the transfer from the load lock chamber 4 to the transfer chamber 3 has been described. And correction can be similarly performed. That is, the transfer start position is set in the load lock chamber 4, and the set arrangement position is set in the transfer chamber 3. Then, when the end effector 23 that has received the substrate 9 from the cassette 41 moves from the transfer start position to the set arrangement position, the position detection and the position deviation detection are similarly performed in the gate valve chamber 5.
Then, a displacement correcting operation is performed as needed.

Further, each processing chamber 1A, shown in FIG.
All the gate valve chambers 5 between 1B, 1C, 1D, 1E, 1F and the transfer chamber 3 are provided with the mark detection system 6 and the vertical direction detection system 7. Therefore, at the time of transfer to the processing chambers 1A, 1B, 1C, 1D, 1E, and 1F, the position of the end effector 23 and the position of the substrate 9 in the gate valve chamber 5 are detected as described above, and the set arrangement position is determined. Can be corrected.

In some cases, the detection and correction of the displacement may be performed when returning to the transfer chamber 3 from each of the processing chambers 1A, 1B, 1C, 1D, 1E, 1F. From the transfer chamber 3 to the processing chambers 1A, 1B,
Although the displacement has already been detected and corrected as necessary when being transported to the substrates 1C, 1D, 1E, and 1F, the position of the substrate 9 in the processing chambers 1A, 1B, 1C, 1D, 1E, and 1F should be considered. When a shift occurs, detection and correction when returning to the transfer chamber 3 are effective. For example, when the substrate 9 is removed from the substrate holder 11 and is not placed at a predetermined position on the end effector 23 but is shifted, detection and correction when returning to the transfer chamber 3 are effective. It is.

Next, the processing chambers 1A, 1B, 1C,
An example of the configuration of 1D, 1E, 1F will be described. The configuration of the processing chambers 1A, 1B, 1C, 1D, 1E, 1F differs depending on the content of the processing. As an example, a configuration in the case of performing a process of creating a barrier film that prevents mutual contamination between two layers will be described. For convenience of explanation, the processing chambers 1A, 1B, 1C, 1D, 1E, 1F are referred to as a first processing chamber 1A, a second processing chamber 1B,..., A sixth processing chamber 1F.

When forming a barrier film, the first processing chamber 1A is configured as a preheat chamber for preheating the substrate 9 prior to the film formation, and the second processing chamber 1B is configured to naturally oxidize the surface of the substrate 9 prior to the film formation. The etching chamber is configured to perform etching for removing the film or the protective film. The third processing chamber 1C and the fourth processing chamber 1D are configured to form a barrier film by sputtering. In many cases, a stacked film of titanium and titanium nitride is used as the barrier film. In this case, a titanium thin film is formed in the third processing chamber 1C, and a titanium nitride thin film 1D is formed in the fourth processing chamber. The fifth and sixth processing chambers 1E and 1F are spare chambers, and are configured as, for example, a cooling chamber when the substrate needs to be cooled.

The configuration of the fourth processing chamber D for performing sputtering will be described in more detail with reference to FIG. As shown in FIG. 2, in the fourth processing chamber 1D, a substrate holder 11 for holding a substrate 9 at a predetermined position,
Sputtering electrode 1 provided opposite substrate holder 11
3 and a gas introduction system 14 for introducing a predetermined gas into the processing chamber 1D.

The sputter electrode 13 is composed of a target made of a material for forming a film, a magnet capable of magnetron sputtering, and the like. Further, a sputter power supply (not shown) for applying a negative high voltage or a high frequency voltage to the target is provided. A predetermined gas is introduced into the processing chamber 1D by the gas introduction system 14, and the pressure in the processing chamber 1D is adjusted to a predetermined value by controlling the exhaust system 100. In this state, a sputter power supply (not shown) is operated to generate a sputter discharge. The target is sputtered to form a predetermined thin film on the surface of the substrate 9 on the substrate holder 11. When a titanium nitride film is formed, sputtering is performed by using a titanium target and introducing nitrogen gas.

The substrate holder 11 has a plate 12 which can be moved up and down. The plate 12 receives the substrate 9 located at the set arrangement position and descends, and places the substrate 9 on the substrate holding surface of the substrate holder 11. Then, after the processing is completed, the substrate 9 is raised to the set arrangement position. Then, from that position, the substrate 9 is transferred to the transfer chamber 3
To be carried out.

As shown in FIG. 1, an external cassette 400 is disposed on the atmosphere side. Then, the unprocessed substrate 9 stored in the external cassette 400 is transported to the cassette 41 in the load lock chamber 4 and
The processed substrate 9 is transferred from the cassette 41 to the external cassette 40.
There is provided an autoloader 401 for transferring the sheet to zero.
The cassette 41 in the load lock chamber 4 has
An elevating mechanism 42 is provided.

Next, the operation of the entire apparatus according to the present embodiment will be described with reference to FIG. The unprocessed substrate 9 is transferred from the external cassette 400 to the load lock chamber 4 by the autoloader 401, and is stored in the cassette 41 in the load lock chamber 4. A predetermined number of unprocessed substrates 9 are accommodated in the cassette 41 in the load lock chamber 4. The transfer robot 21 takes out one substrate 9 from the cassette 41 and transfers it to the first processing chamber 1. When the processing in the first processing chamber 1A is completed, the transfer robot 21 transfers the substrate 9 to the second processing chamber 1B. Then, the next substrate 9 is taken out from the cassette 41 in the load lock chamber 4 and transported to the first processing chamber 1A. Thus, the substrate 9 is taken out of the cassette 41, and the first processing chamber 1A,
The second processing chamber 1B,... Are sequentially transported to the sixth processing chamber 1F for processing. Then, the substrate 9 that has been processed in the sixth processing chamber 1F is returned to the cassette 41 in the load lock chamber 4. Then, the sheet is taken out by the autoloader 401 into the external cassette 400 on the atmosphere side.

In the above operation, as described above, the transfer of the substrate 9 between the load lock chamber 4 and the transfer chamber 3 and the processing chambers 1A, 1B, 1C, 1
When the substrate 9 is transferred between the transfer chambers 3, 1 E, 1 F and the transfer chamber 3, the end effector 2 in the gate valve chamber 5
The position 3 and the position of the substrate 9 are detected, a position shift is obtained by comparing with the teaching data which is data of a correct position, and a position shift correction operation is performed as necessary. For this reason, the substrate 9 is always correctly arranged at each set arrangement position in the apparatus. Therefore, the reproducibility of the processing in each processing chamber 1 is maintained high, and the gate valve chamber 5
An accident such that the substrate 9 collides with the wall of the cassette 41 in the inside is prevented.

Further, at each point on the transfer path from when the load lock chamber 4 exits the load lock chamber 4 to when the transfer path returns to the load lock chamber 4 again, necessary positional deviation is corrected, so that the end effector 23 and the substrate 9 are always in the correct transfer path. The end effector 23 and the substrate 9 move through. For this reason, the possibility that the end effector 23 or the substrate 9 collides with the structural portion of the edge of the opening of the gate valve chamber 5 is significantly reduced.

For example, it is assumed that when the end effector 23 moves from a certain conveyance start position to a certain set arrangement position, the substrate 9 is displaced for some reason. Even when an accident such as a collision does not particularly occur at the time of transport to the set arrangement position, the end effector 23 moves to the next position in a state where the positional deviation is preserved. Therefore, if the distance to the structure is short at the next position, an accident such as a collision may occur. Therefore, it is preferable to detect and correct the positional deviation at as many places as possible on the transport path and eliminate the transport operation that preserves the positional deviation from the viewpoint of eliminating the possibility of collision with the structure. The apparatus according to the present embodiment is very suitable in this respect, since the displacement of the end effector 23 and the substrate 9 can be detected and corrected during all the transports through the gate valve chamber 5.

In the apparatus of the present embodiment, as described above,
The end effector 23 has two marks 25, and the mark detection system 6 detects the two marks 25. This configuration has important significance in relation to the specification of the substrate reference point. If there is only one mark 25, it is almost impossible to determine the position of the substrate reference point from the data of the position of the mark 25. However, when there are two marks 25, the substrate reference point can be easily obtained as described above. As a method of obtaining the center of the substrate 9 without detecting the position of the mark 25, there is a method of processing the image of the outline of the substrate 9 to obtain the center of the substrate 9, but has a disadvantage that it is very complicated and takes time. The number of the marks 25 need not be two, but may be three or more. Increasing the number of marks 25 is preferable because the calculation becomes somewhat complicated, but the calculation accuracy of the substrate reference point is improved.

In the above embodiment, the detector 62 detects the mark 25 of the end effector 23 and the substrate 9 at the same time, but may detect only the mark 23. For example,
In the case where only the movement accuracy of the end effector 23 is a problem exclusively, this configuration is sufficient. Further, the detection of the displacement may be performed only on the substrate 9. When the reliability of the accuracy of the substrate transport system is high and there is essentially no positional deviation of the end effector 23, the position and positional deviation of only the substrate 9 may be detected and necessary correction may be performed.

The structure in which the detector 62 is an image sensor has the significance that the position of the end effector 23 and the substrate 9 can be easily detected. As another configuration of the detector 62, a configuration using a set of a plurality of photosensors can be considered. In this configuration, a plurality of sets of photosensors are arranged at predetermined positions, and position detection is performed in an on / off state. However, such a configuration tends to be large, and it is difficult to perform highly accurate detection.

The mark detection system 6 is provided in the gate valve chamber 5.
The configuration in which the vertical direction detection system 7 is provided has the following significance. In order to correct the displacement at the set arrangement position, it is desirable to detect the displacement of the end effector 23 or the substrate 9 at the place where the displacement is set.
However, in practice it is often difficult. For example, it is actually difficult to provide the mark detection system 6 and the vertical direction detection system 7 in the processing chamber 1. A gas having a deposition action is often used in the processing chamber 1, and the reason is that a detection window provided on a wall portion of the processing chamber 1 is fogged by deposits. When a mark detection system 6 or a vertical direction detection system 7 is provided on the wall of the processing chamber 1 or the wall of the transfer chamber 3, such a wall can be opened and closed for maintenance in the chamber. In some cases, the positions of the mark detection system 6 and the vertical direction detection system 7 are shifted by opening and closing. As a result, there is a problem that the detection accuracy is reduced.

Since the wall constituting the gate valve chamber 5 is rarely made openable and closable, the configuration in which the mark detection system 6 and the vertical direction detection system 7 are provided in the gate valve chamber 5 does not have the above-described problem. , Highly accurate detection can be performed. During the processing of the substrate 9, the opening 54 of the processing chamber 1 is hermetically closed by the gate valve 51, so that a gas having a deposition action reaches the gate valve chamber 5 and the mark detection window 56.
Also, the vertical direction detection window 57 is not fogged.

In the above embodiment, the vertical direction detection system 7 is provided separately from the mark detection system 6 to detect the vertical direction. However, a configuration in which the mark detection system 6 detects the vertical direction may be considered. Can be For example, a configuration is conceivable in which an imaging optical system having a small depth of focus is adopted as the optical system 622 provided in the detector 62, and the position of the mark 25 in the Z direction is obtained from the degree of blurring of the image (focused state). .

The detector 62 is connected to the end effector 23.
The configuration that detects the position of the end effector 23 and the substrate 9 without stopping the end effector 23 while having an image sensor for taking an image of the substrate 9 has an important significance from the viewpoint of the productivity of the apparatus. That is, the detection of the position during the conveyance is performed by the end effector 2 during the conveyance.
It is also possible to stop at step 3. However, stopping the end effector 23 during the transfer increases the transfer time, and ultimately lowers the productivity of the apparatus. On the other hand, if the detection is performed without stopping the end effector 23 during the conveyance by adopting the configuration that holds the image under a certain condition as in the present embodiment, the productivity of the apparatus does not decrease.

As described above, in the device of the present embodiment,
While the substrate 9 is being conveyed from the conveyance start position to the set arrangement position, a positional shift of the end effector 23 or the substrate 9 is detected. This configuration has important significance in terms of improving the productivity of the entire apparatus. In other words, if the configuration is such that the positional deviation is detected after being arranged at the set arrangement position and this is corrected, the next operation cannot be performed until these operations are completed even after the conveyance to the set arrangement position is completed. However, if the configuration is such that the misalignment is detected during the conveyance, the arithmetic processing required for detecting the misalignment can be performed in parallel with the conveyance. Further, in some cases, by correcting the transport direction and the transport distance in the middle, the substrate 9 can be correctly arranged at the set arrangement position without requiring any extra time. For this reason, it can contribute to improvement in productivity.

In this embodiment, as described above, since the teaching is performed and the positional deviation is detected by comparing with the teaching data, highly accurate detection can be performed. As a result, the substrate 9 can be accurately positioned at the set arrangement position. Can be arranged. In addition, since the teaching data in the reference memory can be updated, it is possible to effectively cope with a case where the accuracy of the substrate transfer system is gradually reduced due to wear or the like. In other words, frequent teaching is performed, and the teaching data is updated so as to compensate for such a decrease in the accuracy of the substrate transport system, whereby the substrate 9 can be always arranged at the set arrangement position with high accuracy. .

Further, as described above, since the correction of the positional deviation is performed by driving the end effector 23 by the transfer robot 21, the configuration and the operation required for the correction of the positional deviation are simplified. The correction of the displacement can be performed by another mechanism driven at the set arrangement position. However, this increases the mechanical complexity and the time required.

[0089]

As described above, according to the first aspect of the present invention, two or more marks are provided on the end effector, and these marks are detected by the detector. Can be detected, and the displacement of the substrate can be easily detected. Further, according to the second aspect of the present invention, since the positional deviation in the gate valve chamber is detected, the detection is easy and the detection with high accuracy can be performed. According to the third aspect of the present invention, since the position shift is detected by the detector including the image sensor, the detection is easy and not large, and the detection is performed while moving the end effector.
There is no risk of productivity drop. According to the fourth aspect of the present invention, in addition to the effects of the first, second or third aspect of the present invention, a positional deviation is detected while the substrate is being transported to the set arrangement position. The time required to correctly arrange the substrate at the set arrangement position can be shortened. Also,
According to the fifth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, the positional deviation is detected by comparing the data with the data obtained by correctly arranging it at the set arrangement position. Become. According to the sixth aspect of the present invention, in addition to the effects of the fourth or fifth aspect of the present invention, the position shift can be corrected at each point of the transport path, so that the end effector and the substrate are displaced from the correct transport path. Less to do,
Therefore, the possibility that the end effector or the substrate collides with the structure is significantly reduced. According to the seventh aspect of the present invention, in addition to the effects of the first, second, third, fourth, fifth or sixth aspect of the invention, the correction of the displacement is performed by driving the end effector. This has the effect of simplifying the configuration and operation.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an embodiment of a substrate processing apparatus of the present invention.

FIG. 2 is a schematic sectional view taken along line XX of FIG.

FIG. 3 is a schematic plan view of an end effector 23 used in the apparatus shown in FIGS. 1 and 2;

4 is a front sectional view showing a schematic configuration of a mark detection system 6 for detecting a mark 25 shown in FIG.

FIG. 5 is a schematic front cross-sectional view illustrating a configuration of a vertical direction detection system 7 provided in the apparatus of the present embodiment.

FIG. 6 is a schematic plan view illustrating a positional relationship between a mark detection system 6 and a vertical direction detection system 7;

FIG. 7 is a diagram illustrating a determination made by a determination circuit 812 included in the hold circuit 81, and is a diagram illustrating a hold position set in a space in the gate valve chamber 5;

FIG. 8 is a diagram illustrating a determination performed by a determination circuit 812 included in the hold circuit 81, and is a diagram illustrating a reference pixel row defined on the CCD 621 in relation to the hold position illustrated in FIG.

FIG. 9 is a diagram illustrating a determination performed by a determination circuit 812 included in the hold circuit 81, and is a diagram illustrating a hold condition.

FIG. 10 is a diagram illustrating image processing performed by an image processing circuit.

FIG. 11 is a diagram illustrating image processing performed by an image processing circuit.

FIG. 12 is a diagram for explaining an arrangement at a set arrangement position by manual operation.

FIG. 13 is a view for explaining the transfer of the substrate 9 whose displacement has been corrected.

[Explanation of symbols]

 Reference Signs List 1A processing chamber 1B processing chamber 1C processing chamber 1D processing chamber 1E processing chamber 1F processing chamber 21 transfer robot 23 end effector 25 mark 20 control unit 3 transfer chamber 4 load lock chamber 41 cassette 5 gate valve chamber 51 gate valve 6 mark detection system 62 Detector 621 CCD 7 Vertical direction detection system 8 Signal processing unit 81 Hold circuit 811 Hold memory 812 Judgment circuit 82 Image processing circuit 83 Reference memory 84 Arithmetic circuit 9 Substrate 91 Holder jig 92 Substrate jig

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F031 CA02 FA01 FA11 FA12 GA44 GA47 GA49 GA50 JA05 JA22 JA27 JA38 MA04 MA28 MA29 MA32 NA05 NA08 NA09

Claims (7)

[Claims] 1. A substrate comprising: a processing chamber for performing a predetermined process on a substrate therein; and a substrate transport system for loading an unprocessed substrate into the processing chamber and unloading a processed substrate from the processing chamber. In the processing apparatus, the substrate transport system has an end effector that holds the substrate and a drive mechanism that drives the end effector, and the end effector is provided with at least two marks, and these marks or these marks are provided. And a signal processing unit for processing a signal from the detector to determine a positional deviation from the correct position of the end effector and / or a positional deviation from the correct position of the substrate. A substrate processing apparatus characterized by the above-mentioned. 2. A processing chamber, wherein a plurality of vacuum chambers including a processing chamber for performing predetermined processing on a substrate therein are airtightly connected via a gate valve chamber provided with a gate valve therein. A substrate transport system for loading an unprocessed substrate into the vacuum chamber and unloading the processed substrate from the processing chamber to another vacuum chamber, wherein the substrate transport system holds the substrate and includes at least one substrate. An end effector provided with two marks, a drive mechanism for driving the end effector, a detector for detecting the mark or substrate of the end effector, and a gate valve for the end effector by processing a signal from the detector Misalignment with respect to the correct position in the chamber and / or misalignment of the substrate with respect to the correct position in the gate valve chamber. And a signal processing unit for determining the mark or the substrate when the end effector passes through the gate valve chamber or stops in the gate valve chamber. Substrate processing equipment. 3. A substrate provided with a processing chamber for performing a predetermined process on a substrate therein, and a substrate transport system for loading an unprocessed substrate into the processing chamber and unloading the processed substrate from the processing chamber. A processing apparatus, wherein the substrate transport system has an end effector that holds the substrate and at least one mark is provided, and a drive mechanism that drives the end effector, and detects the mark of the end effector or the substrate. And a signal processing unit for processing a signal from the detector to determine a position shift with respect to a correct position of the end effector and / or a position shift with respect to a correct position of the substrate, and further, the detector includes: An image sensor that captures an image including a mark or a substrate, and moves an end effector to capture an image A substrate processing apparatus, characterized in that to hold in matters and outputs to the signal processor. 4. The substrate is transferred from a transfer start position, which is a position of the substrate when the transfer of the substrate is started, to a set arrangement position finally set as a position where the substrate is to be arranged. 4. The substrate processing apparatus according to claim 1, wherein the end effector or the substrate is located at a position where the end effector or the substrate is taken during the transfer when the end effector moves. 5. The signal processing unit according to claim 1, further comprising: a reference memory in which the data of the correct position is stored; and a data of a position of the end effector or the substrate detected in an actual transfer and the data of the correct position. And a calculation circuit for calculating the positional deviation by comparing the end effector or the substrate or the substrate jig with the end effector or the substrate jig after actually arranging the substrate or the substrate jig at the set arrangement position. The substrate according to claim 4, wherein data obtained by detecting the position taken by the end effector or the substrate or the substrate jig by the detector during the return to the memory can be stored and updated. Processing equipment. 6. The method according to claim 1, wherein a plurality of the transfer start positions and the set arrangement positions are set, and a positional deviation from the correct position is determined during each transfer from the transfer start positions to the set arrangement positions. The substrate processing apparatus according to claim 4, wherein a plurality of the detectors are provided. 7. The apparatus according to claim 1, wherein the drive mechanism of the substrate transport system drives the end effector so as to correct the determined positional deviation.
7. The substrate processing apparatus according to 4, 5, or 6.