WO2014112512A1

WO2014112512A1 - Alignment device and alignment method

Info

Publication number: WO2014112512A1
Application number: PCT/JP2014/050545
Authority: WO
Inventors: 孔木村; 裕利中尾; 智志柴; 雄也坂内
Original assignee: 株式会社アルバック
Priority date: 2013-01-15
Filing date: 2014-01-15
Publication date: 2014-07-24
Also published as: CN104904002A; CN104904002B; KR101739672B1; KR20150088883A

Abstract

[Problem] To provide a technique for adhering a processing mask and a substrate to one another with a high degree of alignment accuracy. [Solution] A processing mask (31) and a substrate (32) are made to approach one another after being positioned with a distance in between, and adhered to one another, the two elements being made to approach one another while performing alignment. Therefore, even if an alignment error occurs while having the two elements approach one another, it is possible to eliminate this error. Even if the vertically suspended part of the substrate (32) comes into contact with the processing mask (31), the two elements are brought further together while performing alignment.

Description

Alignment device and alignment method

The present invention relates to an alignment technique, and more particularly to a technique for shortening the alignment time.

In a technical field that requires fine processing such as a semiconductor manufacturing process and a liquid crystal display device manufacturing process, in order to form a patterned thin film, a thin film is once formed on an object to be processed, and the thin film is then formed into a resist and a photo. A photolithographic process of performing patterning by etching using a mask is performed.

However, the chemical substance used for etching and the chemical substance for stripping the resist may damage the organic thin film when the organic thin film to be patterned or the thin film to be patterned is formed on the organic thin film. Therefore, the photolithographic process cannot be employed.

Therefore, before the film formation process, a processing mask having a patterned through hole is arranged on the film formation target, and the fine particles of the thin film material that has passed through the through hole reach the surface of the film formation target to form the film formation target. A technique for forming a thin film according to a pattern of through holes on the surface of an object is used.

As in the case of the photolithography process, the process mask and the film formation target are aligned with respect to the process using the process mask having the through-hole, and the process mask is placed at a predetermined relative position. In the state where the film formation target is placed, it is necessary to pass the through-holes through the film formation material fine particles, and in order to perform alignment, the processing mask is separated from the film formation target. The alignment mark and the alignment mark of the film formation target are imaged to detect a position error between the processing mask and the film formation target. The film object was moved relative to each other.

However, even if it is moved relative to the distance and direction where the position error should be zero, if the alignment mark between the processing mask and the film formation target is imaged after the movement, the error is not zero. A large error is detected that must be aligned.

This is mainly due to the mechanical error of the moving device that relatively moves the processing mask and the film formation target. After the relative movement in the distance and direction where the detected error becomes zero again, the error again In general, the error is still large, and it is not possible to perform alignment with desired accuracy unless error detection and relative movement are performed many times.

∙ If relative movement and error detection are performed many times, the time required for alignment becomes longer. In addition, since the alignment is performed in a state where the substrate and the processing mask are separated from each other, if the substrate and the processing mask are brought close to each other and an attempt is made to closely contact the substrate and the processing mask, an error occurs during the approach, It cannot be brought into close contact with an accurate alignment.

The present invention was created to solve the above-described problems of the prior art, and is to provide a technique capable of bringing a substrate and a processing mask close to each other with high accuracy in a short time.

JP 2003-306761 A JP 2011-231384 A

An object of the present invention is to provide an alignment method and an alignment apparatus with high alignment accuracy even after a substrate and a processing mask are brought close to each other.

In order to solve the above problems, the present invention moves a mask holding device in which a processing mask is arranged, a substrate holder in which an object to be processed is arranged, and one or both of the mask holding device and the substrate holder. A horizontal movement device that changes a relative position between the processing mask and the processing object, a proximity movement device that causes the mask holding device and the substrate holder to approach each other, and the mask An imaging device that captures an image of a mask alignment mark of the processing mask arranged on a holding device and a substrate alignment mark of the workpiece to be processed arranged on the substrate holder together to obtain an imaging result, the horizontal movement device, A control device that controls and operates the proximity movement device and the imaging device, and the control device is configured to process the processing obtained from the imaging result. An error distance and an error direction between the relative position of the disk and the workpiece and the relative position in the aligned state are obtained, and the horizontal movement is performed to reduce the error distance. An alignment device that operates a device, wherein the control device operates the imaging device to obtain the imaging result while performing the proximity movement by the proximity movement device, and the error distance from the imaging result. And an error detecting step for obtaining the error direction, and a moving step for starting relative movement between the processing mask and the processing object so as to reduce the error distance by the horizontal movement device. It is a set alignment device.
The present invention is an alignment apparatus, the imaging step, the error detection step, the movement step, while making the proximity movement in a state where the processing mask and the suspended portion of the processing object is in contact Is an alignment device set to be repeatedly performed.
The present invention is an alignment apparatus, wherein a speed setting step for setting a relative speed is provided after the error detection step is performed and before the moving step is performed. When the error distance obtained in the detection step is less than or equal to a preset main allowable error amount, the relative speed is set to zero, and when the error distance is larger than the main allowable error amount, the relative speed is The alignment device is set to a predetermined value, and the moving step is configured to set the relative movement to the relative speed.
In the present invention, the mask alignment mark of the processing mask and the substrate alignment mark of the processing object are imaged together with the same imaging device, and the relative position between the processing mask and the processing object when the imaging result is obtained, An error distance and an error direction between a processing mask and a relative position when the processing object is aligned are obtained, and either one or both of the processing mask and the processing object are determined by a horizontal movement device. An alignment method for reducing the error distance by moving the imaging device while operating the imaging device while performing a proximity movement to shorten a separation distance between the processing mask and the processing object that are separated from each other. An error detecting step for obtaining the error distance and the error direction from the imaging result, and the horizontal movement device to calculate the error distance. As fence, a moving step of relatively moving said workpiece and said processing mask, a repeated alignment method.
The present invention is an alignment method, wherein the processing mask and the processing object are in contact with each other while the processing mask and the processing object are separated from each other while the proximity movement is performed. In this alignment method, the imaging step, the error detection step, and the movement step are repeatedly performed.
The present invention is an alignment method, wherein a speed setting step for setting a relative speed is provided after the error detection step is performed and before the moving step is performed. When the error distance obtained in the detection step is less than or equal to a preset main allowable error amount, the relative speed is set to zero, and when the error distance is larger than the main allowable error amount, the relative speed is It is set to a predetermined value, and the moving step is an alignment method for starting the relative movement at the relative speed.
The present invention provides a moving device that changes a relative position between a processing mask and a processing object by moving either or both of the processing mask and the processing object, and a mask alignment mark of the processing mask. And a processing alignment mark of the object to be processed at the same time, and an imaging device that obtains an imaging result, and a control device that controls and operates the moving device and the imaging device. Obtains an error that is a difference between the relative position of the processing mask and the processing target obtained from the imaging result and the relative position of the aligned state, and reduces the error. An alignment device that changes the relative position so that an error distance included in the error and a relative speed that is a speed of relative movement between the processing mask and the processing object. Is set, an imaging step for obtaining the imaging result by the imaging device, and between the processing mask and the processing object from the imaging result obtained by the control device. The error distance of the relative position is obtained, and from the obtained error distance and the error speed relationship, a speed finding step for obtaining the relative speed, and the working mask and the workpiece to be obtained are obtained by the moving device. And a moving step for starting relative movement at a speed is set to be repeatedly performed, and the error speed relation is set with a different relative speed, and an error distance associated with a larger relative speed. Is an alignment device provided with a high accuracy range that is made larger than the error distance associated with the small relative velocity.
The present invention is an alignment apparatus, wherein a constant speed range associated with the relative speed having the same error distance is set in a portion where the error distance is larger than the high accuracy range. Alignment device.
The present invention is an alignment apparatus, wherein after the error distance becomes smaller than a predetermined permissible distance, the processing mask and the processing object are moved in a relatively approaching direction and contacted. is there.
The present invention is an alignment apparatus, wherein the error distance is at least smaller than a predetermined allowable distance, and the error distance is associated with the relative speed of zero value.
According to the present invention, the mask alignment mark of the processing mask and the processing alignment mark of the processing object are imaged at the same time by the imaging device to obtain an imaging result, and the position of the processing mask and the position of the processing object are acquired by the control device. Is an alignment method in which one or both of the processing mask and the processing object is moved by a moving device to reduce the error, and an error distance included in the error And an imaging step of obtaining the imaging result by the imaging device by associating the relative speed, which is a relative movement speed between the processing mask and the processing object, in advance as an error speed relationship; The error distance of the relative position between the processing mask and the processing object is obtained from the imaging result obtained by the control device, and obtained. A speed finding step for obtaining the relative speed from the relationship between the error distance and the error speed, and a moving step for starting relative movement of the working mask and the workpiece by the moving device at the obtained relative speed. And the imaging step, the speed finding step, and the moving step are set to be repeatedly performed, and the relative speed is set differently in the error speed relationship, and the large The error distance associated with the relative speed is an alignment method provided with a high accuracy range that is made larger than the error distance associated with the small relative speed.
The present invention is an alignment method, wherein the error speed relationship is an alignment in which a constant speed range in which the error distance is related to the relative speed having the same value is set in a portion where the error distance is larger than the high accuracy range. Is the method.
The present invention is an alignment method, wherein after the error distance becomes smaller than a predetermined allowable distance, the processing mask and the processing object are moved in a relatively approaching direction and brought into contact with each other. .
The present invention is an alignment method, in which the error distance is associated with the relative velocity having a value of zero in the range where the error distance is at least smaller than a predetermined allowable distance.

Since the relative movement is performed even after the processing mask and the processing object come into contact with each other, the error due to the proximity movement can be reduced.

The figure for demonstrating the alignment apparatus and film-forming apparatus of this invention Graph to explain the error speed relationship (a)-(c): The figure for demonstrating the positional relationship of the image of a mask alignment mark and the image of a board | substrate alignment mark in an imaging result (a) to (c): diagrams for explaining proximity movement Alignment apparatus and film forming apparatus of second example of the present invention

Reference numeral 2 in FIG. 1 indicates an alignment apparatus of the present invention, and the alignment apparatus 2 is provided in the film forming apparatus 3.
The film forming apparatus 3 has a vacuum chamber 10.
The alignment device 2 includes a mask holding device 21 and a substrate holder 22, and the mask holding device 21 and the substrate holder 22 are disposed inside the vacuum chamber 10.

A vacuum exhaust device 19 is connected to the vacuum chamber 10, and the inside of the vacuum chamber 10 is evacuated and placed in a vacuum atmosphere. The vacuum exhaust device 19 continues to operate, and the inside of the vacuum chamber 10 is continuously evacuated. In the mask holding device 21, the processing mask 31 is disposed so as to be replaceable. When the amount of deposits on the processing mask 31 increases, the processing mask 31 is unloaded from the vacuum chamber 10 and another processing mask is disposed in the mask holding device 21. Is done.

In FIG. 1, a substrate 32, which is an object to be processed, is carried into the vacuum chamber 10 and is disposed on the substrate holder 22. The substrate 32 is a transparent substrate such as a glass substrate.
The substrate 32 and the processing mask 31 are horizontally placed on the substrate holder 22 and the mask holding device 21, respectively.

The substrate 32 disposed on the substrate holder 22 is positioned above the processing mask 31 disposed on the mask holding device 21, and the substrate 32 and the processing mask 31 are separated from each other. A film forming source 11 is disposed below the processing mask 31.

In this example, the film forming source 11 is a sputtering target, and a sputtering gas source 18 is connected to the vacuum chamber 10 so that the sputtering gas can be introduced into the vacuum chamber 10 from the sputtering gas source 18. Yes.

The processing mask 31 is a metal plate, and a through-hole (including a through-groove) 33 having a predetermined pattern is formed on the plate. One side of the processing mask 31 disposed in the mask holding device 21 is a substrate 32. The opposite surface faces the film forming source 11.

When the substrate 32 is placed on the substrate holder 22, mechanical alignment is performed, and the processing mask 31 and the substrate 32 are in a state of low-precision alignment.
With respect to the positional relationship when the processing mask 31 and the substrate 32 are aligned, in the state in which the mechanical alignment is performed, the error in the actual relative position is large. In order to increase the accuracy of the alignment, alignment by the alignment device 2 is performed.

The alignment device 2 includes a moving device 14 and an imaging device 12.
The imaging device 12 has two

cameras

12 ₁ and 12 ₂ . Transparent windows 15 ₁ and 15 ₂ are airtightly provided above the substrate holder 22 in the vacuum chamber 10, and the two

cameras

12 ₁ and 12 ₂ are disposed outside the vacuum chamber 10. The substrate 32 disposed on the substrate holder 22 inside the vacuum chamber 10 can be imaged through the windows 15 ₁ and 15 ₂ .

The processing mask 31 and the substrate 32 have a square shape such as a square or a rectangle, and a mask alignment mark and a substrate alignment are arranged at diagonal positions (locations near non-adjacent corners) among the four corners of the processing mask 31 and the substrate 32. At least one mark is provided for each.

The substrate 32 is transparent, and the

cameras

12 ₁ and 12 ₂ can take an image of the processing mask 31 on which the substrate 32 is overlapped by the light transmitted through the substrate 32. The two

cameras

12 ₁ and 12 ₂ The diagonal location where the mask alignment mark and the substrate alignment mark are located is arranged at a location within the imaging range.

In the mechanically aligned state, the mask alignment mark and the substrate alignment mark located at the same diagonal location are close to each other, and the mask alignment mark and the substrate alignment mark that are close to each other at the diagonal location are adjacent to each other. It is adapted to position the camera 12 _1, 12 camera 12 ₁ of one of the _2, 12 ₂ of the imaging range.

When the approach movement to approach the processing mask 31 and the substrate 32 to be described later, processing mask 31 is stationary relative to the camera 12 _1, 12 _2, camera 12 _1, 12 _2, the focus on the mask alignment mark It is located.

Therefore, while the mask alignment mark can also observe details, the substrate alignment mark is located closer to the

cameras

12 ₁ and 12 ₂ than the focal position, and the image is larger than when it is located at the focal point. Easy to blur.

Therefore, the outline of the mask alignment mark has a cross shape with many corners, and if the image is blurred, the corner cannot be detected and the position cannot be specified. The position can be specified accurately.

On the other hand, the outline of the substrate alignment mark has no corners and a larger circle than the mask alignment mark is adopted, so it is difficult to pinpoint the position accurately even if it is located at the focal point, but it is centered even if the image is blurred Can be almost specified, so the position can be specified even with low accuracy.
In the cross shape and the circular shape, it is desirable that the inside of the contour line is painted black when the contour line is black.

Next, the positional relationship between the mask alignment mark and the substrate alignment mark will be described. First, the substrate 32 has an edge portion of the substrate 32 in contact with the substrate holder 22, and the central portion of the substrate 32 is not in the substrate holder 22. As a result, due to the weight of the substrate 32, as shown in FIG. 4A, the substrate 32 is bent and the central portion is suspended.

In consideration of the case where the processing mask 31 is not bent, but the substrate 32 is disposed on the substrate holder 22 in a state where there is no deflection, in that case, in this case, the two substrates respectively located at the diagonal positions apart from each other. The mask alignment mark and the substrate alignment mark are formed so that the alignment mark and the mask alignment mark can be arranged in an overlapping manner. That is, when the processing mask 31 and the substrate 32 are not bent, the distance between the centers of the mask alignment marks at the diagonal positions and the distance between the centers of the substrate alignment marks at the diagonal positions are formed to be equal to each other. When this is done, the portion of the substrate 32 where the thin film is formed faces the through-hole 33, and the processing mask 31 and the substrate 32 are in a positional relationship in which they are accurately aligned.

Since the length of the straight line connecting the centers of the substrate alignment marks is shortened when the substrate 32 is bent, the distance between the centers of the substrate alignment marks is shortened when the substrate 32 is bent. The two substrate alignment marks at the diagonal locations cannot be placed together on the two mask alignment marks at the diagonal locations.

When the substrate 32 is disposed on the substrate holder 22, the substrate 32 disposed on the substrate holder 22 and the processing mask 31 disposed on the mask holding device 21 are separated from each other in parallel if the bending of the substrate 32 is ignored. Is located.
The separation distance between the processing mask 31 and the substrate 32 is a length of a line segment that is located between the processing mask 31 and the substrate 32 and intersects the processing mask 31 and the substrate 32 perpendicularly when bending is ignored. is there.

When the positional relationship in which the processing mask 31 and the substrate 32 are accurately aligned is defined in consideration of the bending of the substrate 32, the processing mask 31 and the bent substrate 32 are arranged in a direction perpendicular to the line segment of the separation distance. When the substrate 32 is brought close to the processing mask 31, the lowermost point of the portion where the substrate 32 is bent and droops comes into contact with the processing mask 31. When the substrate 32 is brought into close contact with the processing mask 31, if the mask alignment mark and the substrate alignment mark overlap, the processing mask 31 before contact and the bent substrate 32 are accurately aligned. It was in the position relationship that was made.

In order to start the alignment method in a state in which the substrate 32 is bent, first, in the imaging step, the two

camera

12 ₁ , 12 ₂ of the imaging device 12 are used to detect the mask alignment mark at the diagonal location. The substrate alignment mark is imaged at the same time, and processing for obtaining the imaging result is performed.

3 (a) is the

imaging result

45a, 45b shows a state of displaying on a single or two units on a display of the inside of one of the camera 12 _first imaging results 45a, other camera 12 _second imaging The result 45b includes one mask

alignment mark image

41a and 41b and one substrate

alignment mark image

42a and 42b.

From the imaging results 45a and 45b of the _two

cameras

12 ₁ and 12 ₂ , the distance between the mask

alignment mark images

41a and 41b and the distance between the substrate

alignment mark images

42a and 42b are not the same, and the mask alignment mark It can be seen that the

images

41a and 41b and the substrate

alignment mark images

42a and 42b cannot be superimposed.

Reference numeral 49 in the imaging results 45a and 45b in FIG. 3A (and the imaging results 46a and 46b in FIG. 3B and the imaging results 47a and 47b in FIG. The diagonal line which connected the center of the mask alignment mark located in a corner place is shown.

When the substrate 32 is deformed by bending, the center of the substrate 32 becomes the lowest point of bending, and the shape when the bent substrate 32 is viewed from directly above is centered on the lowest point of the substrate 32. It seems to have been reduced. Assuming that the substrate 32 in an unbent state and the bent substrate 32 are in a similar relationship, when the mask alignment mark and the substrate alignment mark are in a correctly aligned positional relationship, FIG. Like the imaging results 46a and 46b of (b), the centers of the substrate

alignment mark images

42a and 42b are located on the diagonal line 49, and the center of the substrate alignment mark image 42a in one imaging result 46a is The distance between the center of the mask alignment mark image 41a and the distance between the center of the image 42b of the substrate alignment mark and the center of the image 41b of the mask alignment mark in the other imaging result 46b become equal.

In the imaging results 45a and 45b of FIG. 3A when alignment is performed with low accuracy, the centers of the substrate

alignment mark images

42a and 42b and the centers of the mask

alignment mark images

41a and 41b are accurately The relationship is not shown when the positional relationship is aligned.
After the imaging results 45a and 45b are obtained by the imaging process, the process proceeds to an error detection process.

The imaging device 12 is connected to the control device 13, and the imaging results 45a and 45b are output to the control device 13, and the processing mask 31 and the substrate 32 when the imaging results 45a and 45b are obtained from the imaging results 45a and 45b. And the center relationship between the mask

alignment mark images

41 a and 41 b in the imaging results 45 a and 45 b by the control device 13. A first and second center having a center on one side of a certain mask side center point and a substrate side center point which is the center of the

images

42a and 42b of the substrate alignment mark, and a center on the other side as an end point. Are respectively obtained.

In such first and second imaging vectors, the positional relationship between the processing mask 31 and the substrate 32 is a positional relationship in which the alignment is accurately performed when the center point on the same side is a fulcrum. Are parallel to the diagonal line 49, have the same size, and are opposite in direction.

Reference numerals

51a and 51b in FIG. 3A are the first and second imaging vectors obtained from the imaging results 45a and 45b, and the imaging obtained from the imaging results 46a and 46b when accurate alignment is performed. The processing mask 31 when the imaging results 45a and 45b are obtained in the imaging process from the difference between the

vectors

52a and 52b and the first and

second imaging vectors

51a and 51b obtained from the

actual imaging results

45a and 45b. An error angle, an error distance, and an error direction between the positional relationship with the substrate 32 and the positional relationship between the processing mask 31 and the substrate 32 when accurately aligned are obtained. The error distance is assumed to be the absolute value of the error value.

If the processing mask 31 and the substrate 32 are moved relative to each other and the relative position is changed based on the error direction so that the error angle and the error distance become zero, the processing mask 31 and the substrate 32 are aligned. become.
When the error distance, the error angle, and the error direction are obtained in the error detection process, the process proceeds to the speed finding process in order to determine the relative speed that is the speed of the relative movement.

The control device 13 stores a main allowable error amount and a sub allowable error amount. In the speed finding step, the calculated error value (here, the error distance value) is compared with the sub allowable error amount, When the comparison result indicates that the calculated error value is less than or equal to the sub-allowable error amount, the process proceeds to the proximity process described later and indicates that the calculated error value is greater than the sub-allowable error amount The relative speed is obtained by the following procedure. In addition, the magnitude comparison regarding error distance shall be performed by an absolute value. In the speed finding process, the relative speed is set to zero when shifting to the proximity process.

Assuming that the relative movement speed is a relative speed, the control device 13 stores an error speed relationship (relation between an error value and a relative speed) in which an error distance and a relative speed are associated with each other.
FIG. 2 is a graph showing an example of the error speed relationship, where the horizontal axis represents the error value and the vertical axis represents the relative speed. The error value is the error distance.

For the error speed relationship, a maximum error distance ± D having a predetermined value and an allowable distance ± F are set (−D <−F, F <D), and the error distance E is equal to or greater than the maximum error distance ± D. In the range (E ≦ −D, D ≦ E), the error distance E is associated with a constant non-zero relative speed S, and the error distance E is within the allowable distance ± F or less (−F ≦ E ≦ In F), the error distance E is associated with a zero relative speed S. When the relative speed S is zero, the processing mask 31 and the substrate 32 are relatively stationary.

Within a high accuracy range where the error distance E is larger than the allowable distance ± F and smaller than the maximum error distance ± D (−D <E <−F, F <E <D), different relative speeds are set. Thus, the error distance associated with the large relative velocity is made larger than the error distance associated with the small relative velocity.

Within this high accuracy range, the relative speed is set to be small when the error distance is small. In particular, the error distance and the relative speed are in a linear function, and within the high accuracy range, the error distance is The smaller the is, the closer the relative speed approaches zero.

According to the simulation, when the slope of the linear function is larger, the time during which the error distance E is within the allowable distance ± F or less is shorter.
It should be noted that the relative speed may be set to decrease stepwise in accordance with a function such as a linear function.

In the speed finding process, the control device 13 causes the error after the error angle is eliminated by relatively rotating and moving the process mask 31 and the substrate 32 by an angle at which the error angle disappears. The direction and the error distance may be obtained and stored, and the relative speed may be obtained from the stored error distance and error speed relationship.

In the speed finding process, the control device 13 obtains a relative speed from the error distance obtained from the immediately preceding imaging result and the set error speed relationship, and then the process proceeds to the moving process.
In the moving process, the processing mask 31 and the substrate 32 are relatively moved by the moving device 14 as follows.

The moving device 14 includes a horizontal moving device 14a and a proximity moving device 14b.
The horizontal movement device 14a moves the mask holding device 21 and the substrate holder 22 relative to each other within a plane perpendicular to the line segment of the separation distance, thereby allowing the processing mask 31 disposed on the mask holding device 21 to The substrate 32 arranged on the substrate holder 22 is relatively linearly and rotationally moved within a plane perpendicular to the line segment of the separation distance.
The moving device 14 is controlled by the control device 13, and the operation of the horizontal moving device 14 a and the operation of the proximity moving device 14 b are controlled by the control device 13.

The control device 13 stops the operation of the proximity moving device 14b in advance, and in the moving process, operates the horizontal moving device 14a to change the moving direction of the relative movement between the mask holding device 21 and the substrate holder 22. In order to reduce the error distance and error angle obtained in the immediately preceding error detection process, change based on the error direction obtained in the immediately preceding error detection process, and find the relative movement in the immediately preceding speed finding process. It moves at the value of relative speed.

When the relative movement speed reaches the relative speed obtained in the immediately preceding speed finding step, the moving step ends. However, even if the moving step ends, the relative movement between the processing mask 31 and the substrate 32 is immediately before. The relative speed obtained in the speed finding step is maintained.
When the relative movement speed between the processing mask 31 and the substrate 32 reaches the relative speed obtained in the immediately preceding speed finding process, the moving process is completed while maintaining the relative movement at the relative speed, and the processing is completed. Is transferred to an imaging process.

In the imaging step, as described above, the imaging device 12 uses the two

cameras

12 ₁ and 12 ₂ to capture a set of mask alignment marks and substrate alignment marks at the same time at diagonal positions, and the imaging results are obtained. obtain.
Even during the imaging process, the processing mask 31 and the substrate 32 are relatively moved at the relative speed obtained in the immediately preceding speed finding process, and in this state, the imaging result obtained by imaging is output to the control device 13. Then, the imaging process is completed, and the process proceeds from the imaging process to the error detection process.

In the error detection step, the error distance is obtained from the immediately preceding imaging result, and the obtained error distance is compared with the sub-allowable error amount. Here, based on the comparison result, assuming that the process has been shifted to the speed finding process, the error distance, the error angle, and the error direction are obtained in the immediately preceding error detecting process. If the relative speed is obtained from the error distance and the error speed relationship while the processing mask 31 and the substrate 32 move relative to each other according to the procedure, the speed finding process is terminated, and the process is shifted to the moving process.

In the moving step, the relative movement between the mask holding device 21 and the substrate holder 22 is set to a direction in which the error angle and error distance obtained in the immediately previous error detecting step are reduced, and the relative moving speed is the immediately preceding speed finding. When the relative speed obtained in the process is reached, the process is terminated, and the process proceeds to the imaging process.

As described above, by relatively moving the mask holding device 21 and the substrate holder 22, the imaging mask, the error detection step, and the speed finding step are performed while relatively moving the processing mask 31 and the substrate 32. The moving process is repeatedly performed, and the error distance and the error angle are reduced.

Note that, after the processing in the imaging process is performed and before the processing in the next imaging process is performed, the processing mask 31 and the substrate 32 are relatively moved, so that an imaging result is obtained in the imaging process. After that, even if the error once becomes smaller than the allowable distance, when the imaging result is obtained in the next imaging step, the error may increase and be larger than the sub allowable error amount.
That is, even if the processing mask 31 and the substrate 32 are close to each other and alignment is performed, the alignment may pass through the alignment position. If the distance that passes is large, the error will always be smaller than the sub-allowable error amount. I can't.

In the present invention, when the error distance becomes small, the value of the relative speed set in the speed finding step becomes small, so even if it passes, the distance is shorter than when the relative speed is large, and the error distance is shortened in a short time. Can be less than or equal to the allowable distance.
When the error distance obtained in the error detection step is equal to or smaller than the allowable distance, the relative velocity is set to zero in the speed finding step according to the error speed relationship. In that case, with the relative movement between the mask holding device 21 and the substrate holder 22 stopped, the process proceeds to the proximity process described below.

The proximity moving device 14 b is configured to bring the mask holding device 21 and the substrate holder 22 close to each other and shorten the distance between the mask holding device 21 and the substrate holder 22. The proximity movement device 14 b can move only one or both of the mask holding device 21 and the substrate holder 22.

Before shifting to the proximity process, the processing mask 31 and the substrate 32 are separated from each other, but in the proximity process, the control device 13 moves close to move the processing mask 31 and the substrate 32 in close contact with each other. The apparatus 14b is operated to move either one or both of the mask holding device 21 and the substrate holder 22 and start the proximity movement in which the mask holding device 21 and the substrate holder 22 approach each other.

When the proximity movement of the processing mask 31 and the substrate 32 is started by the proximity process, the processing mask 31 and the substrate 32 are moved in a direction to shorten the separation distance, but in a direction perpendicular to the separation distance. Since it is not moved, it can be considered that the error distance between the processing mask 31 and the substrate 32 and the size of the error direction do not change even when the proximity movement is started.

When the proximity movement is started, the error distance is less than or equal to the sub-allowable error amount. Therefore, even if the proximity movement is started, the state where the error distance is less than or equal to the sub-allowable error amount should be maintained. is there.
However, the operation of the proximity movement device 14b has inaccuracy due to mechanical accuracy, vibration, wear, and the like. In this case, the processing mask 31 and the substrate 32 move relative to each other due to the proximity movement, and an error occurs. The distance and the error angle change. If the error distance or error angle increases after the proximity movement is started, alignment is required.

In order to monitor the magnitude of the error distance and the error angle, the proximity process is terminated after the proximity movement is started, and the processing is shifted to the imaging process.
Imaging is terminated after the imaging result is obtained, and the process proceeds to an error detection step.
The error detection process ends after the error distance, error angle, and error direction are obtained, and the process proceeds to the speed setting process.

The alignment device 2 stores a constant speed value of a predetermined value as a relative speed. In the speed setting step, an error value (here, an absolute value of an error and a magnitude of an error distance) is used. The main allowable error amount is compared and the comparison result shows that the error distance is larger than the main allowable error amount, the relative speed is set to the stored constant speed value, and the error distance is the main allowable error. When the error amount is less than or equal to the error amount, the relative speed is set to zero and the process ends, and the process proceeds to the moving process.

In the moving process, as described above, the relative movement of the mask holding device 21 and the substrate holder 22 in the direction perpendicular to the direction of the separation distance is set so that the error distance and the error direction are reduced. Use relative speed.
When the relative moving speed between the mask holding device 21 and the substrate holder 22 reaches the set relative speed, the moving process ends, and the process proceeds to the imaging process. Movement of the processing mask 31 and the substrate 32 at the set relative speed is maintained.

In this way, the imaging process, the error detection process, the speed setting process, and the movement process are repeatedly performed while moving close to each other, and when the error amount is less than or equal to the main allowable error amount, the separation distance is When it is detected that the error distance is larger than the main allowable error amount without being relatively moved in the vertical direction, the error distance is relatively decreased.
The main error allowable amount may be the same value as the sub error allowable amount or a different value.

While the imaging process, the error detection process, the speed setting process, and the moving process are repeatedly performed, the proximity movement between the mask holding device 21 and the substrate holder 22 is continuously performed, When the distance between the lower end of the hanging portion of the substrate 32 and the surface of the processing mask 31 is moved, the lower end of the hanging portion of the substrate 32 and the surface of the processing mask 31 are as shown in FIG. ,Contact.

Proximity movement is performed after contact, and the area of the contact portion 43 gradually increases as the proximity movement occurs.
Even after contact, the imaging process, error detection process, speed setting process, and movement process are repeated, and in the movement process, the error distance detected in the previous error detection process is larger than the main error tolerance. Is larger, the substrate 32 and the processing mask 31 are relatively moved at a set relative speed in a direction perpendicular to the separation distance while the contact portion 43 slides.
Therefore, the contact area increases with the proximity movement, and accordingly, the portion where the substrate 32 hangs gradually decreases.
As the drooping portion decreases, the distance between the substrate alignment marks located at the diagonal locations of the substrate 32 increases and approaches a state without deflection.

FIG. 4C shows a state when the area of the contact portion 43 is increased, and FIG. 3C shows an accurate distance between the processing mask 31 and the substrate 32 in this state. The imaging results 47a and 47b when the positional relationship is aligned with each other are shown. Even when the contact area increases, the shape when the substrate 32 is viewed from above is the shape when there is no deflection. The

imaging vectors

53a and 53b are parallel to the diagonal line 49, have the same size, and have opposite directions, and the substrate

alignment mark images

42a and 42b are close to the mask

alignment mark images

41a and 41b. Therefore, the size is smaller than the

image pickup vectors

52a and 52b when the accurate alignment is performed before the contact.

As the contact area increases, the force required to move the processing mask 31 and the substrate 32 relatively increases, and the burden on the horizontal movement device 14a increases. The relative speed in the direction perpendicular to the line segment of the separation distance can be terminated by setting the relative speed to zero before the value becomes larger than the predetermined value.

The relative speed may be set to zero when the force required for the relative movement becomes larger than a predetermined value, or the distance between the mask holding device 21 and the substrate holder 22 is detected. Thus, the relative speed may be set to zero when the distance becomes shorter than the predetermined distance due to the proximity movement.

As described above, according to the present invention, even if the processing mask 31 and the substrate 32 are in contact with each other, the alignment between the processing mask 31 and the substrate 32 is performed. Since the alignment accuracy when the two come into close contact with each other is improved, the place where the thin film on the surface of the substrate 32 is formed can be accurately arranged on the through hole 33 of the processing mask 31.

Therefore, when the processing mask 31 and the substrate 32 are brought into full contact with each other and brought into close contact with each other, the processing mask 31 and the substrate 32 are in a state close to an accurately aligned state within the range of the main allowable error. Therefore, in this state, the film forming material particles are released from the film forming source 11, and the film forming material particles (including vapor) that have passed through the through holes 33 of the processing mask 31 reach the surface of the substrate 32. As a result, the thin film is accurately formed on the surface of the substrate 32 within the range of the main allowable error amount at the position where the thin film is to be formed.

When the thin film has grown to a predetermined thickness, the release of the particles of the film forming material from the film forming source 11 is stopped, the processing mask 31 and the substrate 32 are separated from each other, the substrate 32 is removed from the substrate holder 22, and the vacuum is removed. The substrate 10 is carried out of the tank 10, an undeposited substrate is placed on the substrate holder 22, alignment is performed in the same procedure as described above, and a film is formed on the substrate surface.

<Other examples>
In the above speed setting process, when the error distance is larger than the main permissible error amount, it was a constant value, but instead of the speed setting process, the speed determination process is performed, and the same relationship as the error speed relationship when not moving close or Using a different relationship, the relative speed having the magnitude related to the value of the error distance may be used as the value of the relative movement when moving close. In this case, if the error is reduced, the relative speed between the processing mask and the workpiece is also reduced, so the distance that the machining mask and the workpiece pass is reduced, and high-accuracy alignment takes a short time. Can do.

Also, the initial range is set in a range where the error distance is larger than the high accuracy range in the error speed relationship when not moving close and the error speed relationship when moving close. The error distance of the initial range is related to a constant relative speed regardless of the magnitude, and the constant relative speed is equal to the maximum relative speed set in the high accuracy range, or The value is larger than that. Therefore, even when the error distance obtained from the picked-up image pickup result is small, the relative speed does not change when the obtained error distance is included in the initial range. Therefore, the alignment device 2 moves linearly at a constant relative speed while the error distance obtained from the imaging result is included in the initial range.

The imaging result of the present invention is an image in the field of view including both the mask alignment mark of the processing mask and the substrate alignment mark of the substrate, and the imaging result may be a moving image or a still image. Good. A still image extracted from a moving image is also included in the imaging result.

In the present invention, when the processing mask 31 and the substrate 32 move relative to each other, the processing mask 31 and the substrate 32 can move linearly as a relative movement after the processing mask 31 and the substrate 32 rotate, and can move linearly while rotating. The case of relative movement is included. In short, the relative movement is not limited to linear movement.

The film formation source 11 is a sputtering target. A sputtering gas is introduced from a sputtering gas source 18 into a vacuum chamber 10 in a vacuum atmosphere, and a sputtering voltage is applied to the film formation source 11 to generate plasma of the sputtering gas. Then, the film forming material particles, which are sputtering particles, are emitted from the surface of the film forming source 11 to form a patterned thin film.

Therefore, although the film formation source 11 is a sputtering target, the film formation source of the present invention is not limited to the sputtering target. For example, the film formation source is a vapor deposition source and is disposed in a crucible of the vapor deposition source. The deposited film-forming material may be heated to release particles of the film-forming material that is the vapor of the film-forming material.

Furthermore, the alignment method of the present invention is not limited to the case where the substrate and the processing mask are aligned to form a film, but the substrate and the processing mask are aligned, and the surface of the substrate passes through the processing mask. It can be used in a process for processing according to the shape of the hole 33, and can also be applied to an etching method for etching according to the shape of the through-hole 33, for example.

The numerical values used for the error speed relationship and the allowable distance may be stored in an external storage circuit connected to the control device 13 or may be recorded on a recording medium. It may be read into an internal storage circuit. In short, it is sufficient that the error speed relationship is set in the alignment device 2.
<Second example>
The example in which the substrate having no flexibility and the processing mask are aligned has been described above, but the processing object used in the present invention may be a film of an organic compound having flexibility.

5 indicates a second example alignment apparatus in which the object to be processed is a film 32b. The alignment apparatus 2b is provided in the film forming apparatus 3b of the second example of the present invention.

For the alignment device 2b of the second example, the same members as those of the alignment device 2a of the first example are denoted by the same reference numerals, and the description thereof is omitted. Similarly, for the film formation device 3b of the second example, the first example The same members as those of the film forming apparatus 3a are denoted by the same reference numerals and description thereof is omitted. In the film forming apparatus 3 b of the second example shown in FIG. 5, the film 32 b faces the processing mask 31 disposed on the mask holding device 21.

In the vacuum chamber 10, a winding device 35 and an unwinding device 36 are arranged.
The unwinding device 36 is provided with an unwinding roll 34 composed of the wound film 32b. The portion of the film 32b facing the processing mask 31 is unwound from the unwinding roll 34, and the processing mask 31 It is a portion that passes through the facing position, and becomes a part of the film 32b that is mounted on the winding device 35.

A driving device 37 is connected to the winding device 35. The winding device 35 and the unwinding device 36 are rod-shaped, and when rotated by the driving device 37 with one end of the film 32b fixed, the unwinding roll 34 and the unwinding device 36 are pulled by pulling the film 32b. , And the film 32b is unwound from the unwinding roll 34 and wound by the winding device 35.

The film 32b unwound from the unwinding roll 34 travels in the vacuum chamber 10, and passes through the positions where the

imaging devices

12 ₁ and 12 ₂ take images.
A mask alignment mark is formed on the processing mask 31, and a processing alignment mark is formed on the film 32b.

Here, the processing alignment mark provided on the film 32b is imaged without interruption even when the film 32b travels, and an error can be obtained from the imaging result. For example, the processing alignment mark is the film 32b. Are provided along the longitudinal direction without any breaks, or are arranged along the longitudinal direction.

In any case, whether the film 32b is stopped or traveling, the imaging process obtains the imaging results of the mask alignment mark and the processing alignment mark captured at the same time by the

imaging devices

12 ₁ and 12 _2. In the speed finding step, the error angle, the error distance, and the error direction between the processing mask 31 and the film 32b are detected from the latest imaging result and the set error speed relationship.

The portion of the film 32b that faces the processing mask 31 is running so as to be parallel to the processing mask 31, and in the moving process of the alignment device 2b of the second example, the moving device 14 The processing mask 31 is rotated and linearly moved with respect to the stationary vacuum chamber 10 and the like while being positioned in the same plane without changing the distance between the plane where the film 32b is located and the plane where the film 32b is located. The mask holding device 21 is rotated and linearly moved to move the processing mask 31 and the film 32b relative to each other. This relative movement is set to the relative speed obtained in the latest speed finding process.

If the straight line extending in the longitudinal direction or the straight line extending in the running direction of the film 32 is referred to as the central axis, connecting the central positions in the width direction of the film 32b, the central axis of the film 32b is determined from the imaging result of the imaging process in the speed finding process. However, an error consisting of an error angle, an error distance in a direction perpendicular to the central axis, and an error direction is obtained.

In the speed finding process, as in the first example, the control device 13 obtains a correction error direction and a correction error distance when the processing mask 31 is rotationally moved so that the error angle becomes zero. The relative speed may be obtained from the relationship between the error distance and the error speed, with the direction as the error direction and the correction error distance as the error distance.
In the moving process, the mask holding device 21 is linearly moved with the rotational movement so as to reduce the error.

When a thin film is formed on the film 32b by the film forming apparatus 3b of the second example, first, an imaging process is performed before or immediately after the film 32b is traveled, and a processing alignment mark and a mask alignment mark are captured by the imaging apparatus. After imaging at 12 ₁ and 12 ₂ and obtaining the imaging result, the process proceeds to the speed finding process, and after obtaining the relative speed from the error distance and the error speed relationship, the process proceeds to the moving process and obtained in the speed finding process. The relative movement of the processing mask 31 in the obtained error direction is started at the relative speed.

Such an imaging process, a speed finding process, and a moving process are repeated, and even if the error increases as the film 32b travels, the error can be reduced. Can do.

When the error distance is less than or equal to the allowable distance, the relative speed is set to zero, and the release of the film forming material particles from the film forming source 11 is started. Of the released film forming material particles, a film formed on the surface of the traveling film 32b is formed by the film forming material particles that have passed through the through holes 33 (including the through grooves) formed in the processing mask 31. It is formed. The value of the allowable distance may be changed after the start of the release of the film forming material particles.

After the discharge of the film forming material particles from the film forming source 11 is started, that is, during the thin film formation, the imaging process, the speed finding process, and the moving process are repeated to reduce the error.
The thin film to be formed has an elongated shape along the running direction, and a plurality of elongated thin films are arranged in parallel to each other on the film 32b.

When the film 32b starts running, the distance generated between the processing mask 31 and the film 32b varies, but the generated error is reduced in the moving process, and a thin film with a highly accurate pattern can be obtained.

<Other examples>
In the above error speed relationship, the initial range is set in a range where the error distance is larger than the high accuracy range, and the error distance in the initial range is related to a constant relative speed regardless of the size. .

This constant relative speed is equal to or greater than the maximum relative speed set in the high accuracy range, and is imaged after or during the movement process. Even when the error distance obtained from the imaging result becomes small, the relative speed of the same magnitude is associated when the obtained error distance is included in the initial range.

Even in the alignment devices 2a and 2b of the first and second examples, the linear movement is performed at a constant relative speed while the error distance obtained from the imaging result is included in the initial range.

The imaging result of the present invention is an image in the field of view including both the mask alignment mark of the processing mask and the processing alignment mark of the processing object, and the imaging result is a still image even if it is a moving image. There may be. A still image extracted from a moving image is also included in the imaging result.

Further, the present invention includes a case where the processing mask 31 and the processing object rotate and then move linearly as relative movement, and a case where the processing mask 31 and the processing object move relative to each other by linear movement while rotating. Further, the relative movement is not limited to linear movement.

The film formation source 11 is a sputtering target. A sputtering gas is introduced from a sputtering gas source 18 into a vacuum chamber 10 in a vacuum atmosphere, and a sputtering voltage is applied to the film formation source 11 to generate plasma of the sputtering gas. The film forming material 11 is sputtered and discharged from the surface of the film forming source 11 to form a patterned thin film. However, the film forming source 11 is not limited to the sputtering target. The film source is a vapor deposition source, and the film forming material disposed in the crucible of the vapor deposition source may be heated to release particles of the film forming material that is vapor of the film forming material.

Furthermore, the alignment method of the present invention is not limited to the case where the processing object and the processing mask are aligned to form a film, but the processing object and the processing mask are aligned and the surface of the processing object is aligned. Can be used in a process of processing according to the shape of the through hole 33 of the processing mask, and includes a process of etching according to the shape of the through hole 33, for example.

It should be noted that the numerical values used such as the error speed relationship and the allowable distance may be stored in an external storage circuit connected to the control device 13 or recorded on a recording medium and may be stored by the control device 13. The data may be read into the internal storage circuit. In short, it is sufficient that the error speed relationship is set in the alignment devices 2a and 2b in the first and second examples.

3 ... Film forming apparatus 10 ... Vacuum chamber 11 ...

Film forming sources

12, 12 ₁ , 12 ₂ ... Imaging device 13 ... Control device 14 ... Moving device 21 ... Mask holding device 22 ... Substrate holder 31 ... Processing mask 32 ... Substrate

Claims

A mask holding device on which a processing mask is arranged;
A substrate holder on which a workpiece is placed;
A horizontal movement device that changes a relative position between the processing mask and the processing object by moving one or both of the mask holding device and the substrate holder;
A proximity movement device for performing a proximity movement in which the mask holding device and the substrate holder approach each other;
An imaging device that captures an image together with a mask alignment mark of the processing mask disposed in the mask holding device and a substrate alignment mark of the processing object disposed in the substrate holder;
A control device that controls and operates the horizontal movement device, the proximity movement device, and the imaging device;
Have
The control device includes an error distance and an error direction between a relative position of the processing mask and the processing target obtained from the imaging result, and a relative position in a state of alignment. An alignment device that operates the horizontal movement device so as to reduce the error distance,
While the control device makes the proximity movement by the proximity movement device,
An imaging step of operating the imaging device to obtain the imaging result;
An error detection step of obtaining the error distance and the error direction from the imaging result;
An alignment device set to repeatedly perform a moving step of starting relative movement between the processing mask and the processing object so as to reduce the error distance by the horizontal moving device.
The imaging step, the error detection step, and the moving step are set to be repeatedly performed while the proximity movement is performed in a state where the processing mask and a suspended portion of the processing object are in contact with each other. The alignment device according to claim 1.
After the error detection step is performed and before the movement step is performed, a speed setting step for setting a relative speed is provided. In the speed setting step, the error distance obtained in the immediately preceding error detection step is The relative speed is set to zero when it is equal to or less than a preset main allowable error amount, and the relative speed is set to a predetermined value when the error distance is larger than the main allowable error amount,
The alignment apparatus according to claim 1, wherein the moving step is configured to set the relative movement to the relative speed.
The mask alignment mark of the processing mask and the substrate alignment mark of the processing target are imaged together with the same imaging device, and the relative position between the processing mask and the processing target when the imaging result is obtained, the processing mask, and the An error distance and an error direction between the relative position when the processing object is aligned are obtained, and either or both of the processing mask and the processing object are moved by a horizontal movement device, An alignment method for reducing the error distance,
While performing proximity movement to shorten the separation distance between the processing mask and the processing object that are separated,
An imaging step of operating the imaging device to obtain the imaging result;
An error detection step of obtaining the error distance and the error direction from the imaging result;
An alignment method in which the horizontal movement device repeatedly performs a moving step of relatively moving the processing mask and the processing target so as to reduce the error distance.
The imaging step, the error detection step, while moving the proximity to the portion where the processing mask and the processing target object are separated in a state where the processing mask and the suspended portion of the processing target object are in contact with each other The alignment method according to claim 4, wherein the moving step is repeatedly performed.
After the error detection step is performed and before the movement step is performed, a speed setting step for setting a relative speed is provided. In the speed setting step, the error distance obtained in the immediately preceding error detection step is The relative speed is set to zero when it is equal to or less than a preset main allowable error amount, and the relative speed is set to a predetermined value when the error distance is larger than the main allowable error amount,
The alignment method according to claim 4, wherein the moving step starts the relative movement at the relative speed.
A moving device that changes the relative position between the processing mask and the processing object by moving either or both of the processing mask and the processing object;
An imaging device that captures an image of a mask alignment mark of the processing mask and a processing alignment mark of the processing object at the same time, and obtains an imaging result;
A control device that controls and operates the moving device and the imaging device;
Have
The control device obtains an error that is a difference between a relative position of the processing mask and the processing target obtained from the imaging result and a relative position of the aligned state, An alignment device that changes the relative position to reduce errors,
An error speed relationship is set in which an error distance included in the error and a relative speed that is a relative movement speed between the processing mask and the processing object are associated with each other,
An imaging step of obtaining the imaging result by the imaging device;
The error distance of the relative position between the processing mask and the object to be processed is obtained from the imaging result obtained by the control device, and the relative speed is obtained from the obtained error distance and the error speed relationship. Speed process,
A moving step of starting relative movement of the processing mask and the processing object at the determined relative speed by the moving device;
Is set to repeat,
In the error speed relation, different relative speeds are set, and an error distance associated with a large relative speed is larger than an error distance associated with a small relative speed. Alignment device provided.
The alignment apparatus according to claim 7, wherein a constant speed range related to the relative speed having the same value of the error distance is set in a portion where the error distance is larger than the high accuracy range in the error speed relationship.
9. The method according to claim 7, wherein after the error distance becomes smaller than a predetermined permissible distance, the processing mask and the processing object are moved and brought into contact with each other relatively. The alignment device described.
10. The alignment device according to claim 9, wherein the relative distance having a value of zero is associated with the error distance in a range where the error distance is at least smaller than a predetermined allowable distance.
The imaging device captures the mask alignment mark of the processing mask and the processing alignment mark of the processing target object at the same time to obtain an imaging result, and the control device determines between the position of the processing mask and the processing target position. An alignment method for obtaining a relative error and reducing the error by moving either one or both of the processing mask and the processing object by a moving device,
An error distance included in the error and a relative speed that is a relative movement speed between the processing mask and the processing object are associated in advance as an error speed relationship,
An imaging step of obtaining the imaging result by the imaging device;
The error distance of the relative position between the processing mask and the object to be processed is obtained from the imaging result obtained by the control device, and the relative speed is obtained from the obtained error distance and the error speed relationship. Speed process,
A moving step of starting relative movement of the processing mask and the processing object by the moving device at the determined relative speed;
Have
The imaging step, the speed finding step, and the moving step are set to be repeated,
In the error speed relationship, different relative speeds are set, and an error distance associated with a large relative speed is larger than an error distance associated with a small relative speed. Alignment method provided.
12. The alignment method according to claim 11, wherein in the error speed relationship, a constant speed range in which the error distance is associated with the relative speed having the same value is set in a portion where the error distance is larger than the high accuracy range.
13. The method according to claim 11, wherein, after the error distance becomes smaller than a predetermined allowable distance, the processing mask and the processing target are moved in a relatively approaching direction and brought into contact with each other. Alignment method.
14. The alignment method according to claim 13, wherein the relative distance having a value of zero is associated with the error distance in a range where the error distance is smaller than at least a predetermined allowable distance.