JP2022038048A - Mark detection device, alignment device, film-forming device, mark detection method, and film-forming method - Google Patents

Abstract

To provide a technique for increasing detection precision of a mark formed on a board for alignment.SOLUTION: A mark detection device for detecting a board mark of a board having the board mark that is a linear mark and in which the thickness of a line in a first area near an edge of a line is larger than the thickness of a line in a second area other than an area near the edge includes photographing means for photographing an image of a captured area including the board mark, and detection means for detecting a position of the board mark by comparing a photographed image photographed by the photographing means with a model image, and the model image is an image that is linear while the length of a line is equivalent to the second area of the board mark.SELECTED DRAWING: Figure 6

Description

The present invention relates to a mark detection device.

There is a mark detection device that detects a mark provided on the substrate or the like from image data obtained by photographing the substrate or the like. Such a mark detection device is used, for example, as an alignment device for aligning a substrate and a mask, which is provided in a film forming apparatus for forming a film of a film forming material on a substrate via a mask. Be done. Such an alignment device takes an image of the substrate and the mask, detects the substrate mark provided on the substrate and the mask mark provided on the mask, and moves the substrate or the mask so that the distance between the marks satisfies a predetermined relationship. And align. At this time, in order to improve the alignment accuracy, it is necessary to extract the substrate mark and the mask mark from the captured image as accurately as possible.

An example of such a film forming apparatus is an organic semiconductor manufacturing apparatus used for manufacturing an organic semiconductor. In the manufacture of organic semiconductors, alignment marks (board marks) for substrates are formed on wafer substrates such as silicon by laser processing. Then, a mask having a desired pattern is brought close to the substrate, and alignment is performed based on the positional relationship between the alignment mark (mask mark) formed on the mask and the substrate mark.

Further, as another example of the film forming apparatus, there is a film forming apparatus for organic EL for manufacturing an organic EL display apparatus. In the case of an organic EL display, a mask having a pixel pattern formed on a substrate such as glass is aligned in a film forming apparatus, and an organic material or a metal material is formed through the mask to form a functional layer or a functional layer on the substrate. Form an electrode metal layer.
In order to perform high-precision film formation in such a film-forming apparatus, it is necessary to align the substrate and the mask with high accuracy.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2019-179186) describes a technique using an alignment mark formed on a substrate by laser processing. That is, in Patent Document 1, an alignment mark is formed by irradiating a substrate with a spot-shaped luminous flux using a laser, and an alignment is performed using an image obtained by photographing a region including the alignment mark.

Japanese Unexamined Patent Publication No. 2019-179186

In order to improve the alignment accuracy between the substrate and the mask, it is required to detect the substrate mark more accurately.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for improving the detection accuracy of marks formed on a substrate for alignment.

The present invention adopts the following configuration.
That is,
The substrate having a substrate mark which is a linear mark and whose thickness of the line in the first region near the end of the line is larger than the thickness of the line in the second region other than near the end of the line. In the mark detection device that detects the board mark,
A shooting means for shooting an image of the imaging area including the board mark, and
A detection means for detecting the position of the substrate mark by comparing the photographed image captured by the photographing means with the model image.
The model image is a mark detection device characterized in that the image is linear and the length of the line corresponds to the second region of the substrate mark.

According to the present invention, it is possible to provide a technique for improving the detection accuracy of marks formed on a substrate for alignment.

Schematic diagram of a production line for electronic devices including a film forming apparatus Cross-sectional view showing the internal configuration of the film forming apparatus Diagram illustrating mark detection and alignment Diagram showing the bulge at the end of the board mark and the model board mark Flow diagram explaining the flow from mark detection to film formation processing The figure explaining the modification of the model board mark in an Example. The figure which shows another form of a board mark Diagram illustrating multiple modified model board marks

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the following description merely illustrates the preferred configurations of the present invention, and the scope of the present invention is not limited to those configurations. Further, unless otherwise specified, the hardware configuration and software configuration, processing flow, manufacturing conditions, dimensions, materials, shapes, etc. of the apparatus in the following description are intended to limit the scope of the present invention to these. not.

Here, when forming a film having some desired shape on the substrate, a mask having a mask pattern suitable for the shape of the formed film is used. Thereby, each layer to be formed into a film can be arbitrarily formed. Then, in order to form the film at a desired position on the substrate, it is necessary to accurately align the relative positions of the substrate and the mask with the mask. At the time of alignment, the alignment mark (board mark) formed on the substrate and the alignment mark (mask mark) formed on the mask are usually imaged by an imaging means such as a camera, and the alignment is performed by the alignment means such as an actuator. That is, for good alignment, it is preferable that at least the substrate mark and the mask mark can be detected with high accuracy.

As described above, the present invention is preferably used in a technique for detecting an alignment mark (board mark and / or mask mark). Therefore, the present invention can be regarded as a mark detection device or a mark detection method. The present invention can also be regarded as an alignment device or alignment method for aligning a substrate and a mask using the detected marks. The present invention can also be regarded as a film forming apparatus or a film forming method using such an alignment apparatus or an alignment method. The present invention is also regarded as a manufacturing apparatus or a method for manufacturing an electronic device using such a film forming apparatus or a film forming method.

The present invention is preferably applicable when forming a thin film material layer having a desired pattern on the surface of a substrate via a mask. As the material of the substrate, any material such as silicon, glass, resin, and metal can be used. As the film forming material, any material such as an organic material and an inorganic material (metal, metal oxide) can be used. The technique of the present invention is typically applied to an apparatus for manufacturing electronic devices and optical members. The present invention can be applied to, for example, an organic semiconductor manufacturing apparatus and an organic semiconductor manufactured using the same. The present invention is also suitable for organic electronic devices such as organic EL displays, manufacturing devices for organic EL display devices using the same, thin-film solar cells, and organic CMOS image sensors.

<Examination of conventional technology>
As a result of diligent studies by the inventors, it was found that the detection accuracy of the substrate mark may be lowered in the conventional technique.

FIG. 3 is a diagram illustrating detection of a substrate mark. Here, a case where a substrate mark is formed on a wafer substrate by laser processing will be given as an example.
3 (a) and 3 (b) are ideal diagrams according to the conventional example, and are an ideally formed substrate mark 104 and an internal model for detecting the substrate mark 104, respectively. A model board mark 174 is shown. The model board mark 174 is a model image showing the shape of the board mark and is stored in the storage means. Further, FIG. 3C is a diagram showing a state in which the mask mark 224 is included together with the substrate mark 104 in the imaging region.

A case where the substrate mark is detected by using the substrate mark 104 of FIG. 3A and the model substrate mark of FIG. 3B will be described. The mark detection device compares the data of the substrate mark 104 in the imaging region 264 imaged by the photographing means with the model substrate mark 174 by an image recognition algorithm such as pattern matching. When the substrate mark 104 matching the shape of the model substrate mark 174 is detected, the mark detection device stores the position of the detected substrate mark 104 as coordinates. When the mark detection device detects the mask mark 224, the alignment device aligns the substrate with the mask.

On the other hand, FIG. 4A is a diagram showing an actual linear substrate mark formed by processing a wafer substrate using a laser processing technique according to a conventional example.
In this case, the central portion 104m of the substrate mark has the same thickness as the ideal substrate mark, but the end portion 104t of the substrate mark may have a bulging shape. That is, in the linear mark, the thickness of the line in the first region near the end of the line may be larger than the thickness of the line in the second region other than the vicinity of the end. The degree and shape of the bulge with respect to the central portion (second region) 104m of the end portion (first region) 104t varies depending on the material and processing method of the substrate, but the occurrence of such bulge affects the accuracy of mark detection. May give.

That is, even if the substrate mark 104 having the shape shown in this figure is to be detected by matching with the model substrate mark 174 shown in FIG. 4 (b), the shape of the first region 104t of the substrate mark matches the model substrate mark 174. do not. Therefore, the recognition accuracy of the board mark 104 may be lowered, or the coordinate accuracy at the time of position detection may be lowered. As a result, the alignment accuracy may decrease.

Therefore, in the following description, an example will be described in which even a substrate mark having deformation such as a bulge at the end can be detected satisfactorily. The present invention is not limited to the case where the wafer is laser-machined, and can be applied to the case where the end portion is bulged or deformed due to the influence of the processing when marking at least one of the substrate and the mask.

<Example 1>
(Electronic device production line)
FIG. 1 is a plan view schematically showing the configuration of an electronic device manufacturing line. Such a production line is a film forming system including a film forming apparatus. Here, the production line of the organic EL display will be described. When manufacturing an organic EL display, a substrate of a predetermined size is carried into the production line, a film of the organic EL or a metal layer is formed, and then a post-treatment step such as cutting the substrate is performed.

As shown in FIG. 1, the film forming cluster 1 on the production line includes a transport chamber 130 arranged in the center, and a film forming chamber 110 and a mask stock chamber 120 arranged around the transport chamber 130. The film forming chamber 110 includes a film forming apparatus, and a film forming process is performed on the substrate 10. The mask stock chamber 120 stores masks before and after use.

The transport robot 140 installed in the transport chamber 130 carries the substrate 10 and the mask 220 into the transport chamber 130 and carries them out from the transport chamber 130. The transfer robot 140 is, for example, a robot in which a robot hand for holding a substrate 10 and a mask 220 is attached to an articulated arm. Each chamber such as the film forming chamber 110, the mask stock chamber 120, the transport chamber 130, the buffer chamber 160, and the swivel chamber 170 maintains a high vacuum state in the manufacturing process of the organic EL display panel.

The film forming cluster 1 has a pass chamber 150 for transporting the substrate 10 flowing from the upstream side in the substrate transport direction to the transport chamber 130, and the substrate 10 for which the film forming process has been completed is transported to another film forming cluster on the downstream side. A buffer chamber 160 for this is included. When the transfer robot 140 in the transfer chamber 130 receives the substrate 10 from the pass chamber 150, the transfer robot 140 transfers the substrate 10 to one of the plurality of film forming chambers 110. The transfer robot 140 also receives the substrate 10 for which the film formation process has been completed from the film formation chamber 110 and conveys it to the buffer chamber 160. In the illustrated example, a swivel chamber 170 that changes the direction of the substrate 10 is provided on the upstream side of the pass chamber 150 and the downstream side of the buffer chamber 160.

(Film formation device)
FIG. 2 is a cross-sectional view schematically showing the configuration of the film forming apparatus. Each of the plurality of film forming chambers 110 is provided with a film forming apparatus 108 (also referred to as a vapor deposition apparatus). Transfer of the substrate 10 to and from the transfer robot 140, detection of the substrate mark provided on the substrate 10, detection of the mask mark provided on the mask 220, adjustment (alignment) of the relative positions of the substrate 10 and the mask 220, and on the mask. A series of film forming processes such as fixing the substrate 10 and forming a film (deposited film) are performed by each component of the film forming apparatus.

In the following description, an XYZ Cartesian coordinate system with the vertical direction as the Z direction is used. In the XYZ Cartesian coordinate system, when the substrate is fixed so as to be parallel to the horizontal plane (XY plane) at the time of film formation, the lateral direction (direction parallel to the short side) of the rectangular substrate 10 having the long side and the short side is set. The X direction and the longitudinal direction (direction parallel to the long side) are defined as the Y direction. Further, the angle of rotation around the Z axis is represented by θ.

The film forming apparatus 108 has a vacuum chamber 200. The inside of the vacuum chamber 200 is maintained in a vacuum atmosphere or an atmosphere of an inert gas such as nitrogen gas. Inside the vacuum chamber 200, a substrate support unit 210, a mask 220, a mask stand 221, a cooling plate 230, and an evaporation source 240 are provided.

The board support unit 210 is a board support means having a function as a holder for supporting the board 10 received from the transfer robot 140. The mask 220 is, for example, a metal mask and has an opening pattern corresponding to a thin film pattern formed on the substrate. The mask 220 is installed on a frame-shaped mask base 221 which is a mask support unit, and after the substrate 10 is positioned and held on the mask, film formation is performed. The board support unit 210 is composed of, for example, a support frame provided with a plurality of supports for supporting the periphery of the board 10 by mounting or sandwiching.

The cooling plate 230 is a plate-shaped member that contacts the surface of the substrate 10 on the side opposite to the surface that contacts the mask 220 during film formation and suppresses the temperature rise of the substrate 10 during film formation. The cooling plate 230 is the substrate 1
By cooling 0, deterioration and deterioration of the organic material are suppressed. The cooling plate 230 may also serve as a magnet plate. The magnet plate is a member that enhances the adhesion between the substrate 10 and the mask 220 at the time of film formation by attracting the mask 220 by a magnetic force. In order to improve the adhesion between the substrate 10 and the mask 220, the substrate support unit 210 may hold both the substrate 10 and the mask 220 and bring them into close contact with each other by an actuator or the like.

The evaporation source 240 is a film forming means including a container (crucible) for accommodating a vapor deposition material, a heater, a shutter, a drive mechanism, an evaporation rate monitor, and the like. The film forming source is not limited to the evaporation source 240. For example, the film forming apparatus 108 may be a sputtering apparatus using a sputtering target as a film forming source.

The control unit 270 controls the operation of each actuator of the actuator unit 282, capture control and image data analysis of the camera 261, carry-in / out control and alignment control of the substrate 10 and the mask 220, film formation source control, film formation control, and the like. Perform various controls. The control unit 270 can be configured by, for example, a computer having a processor, storage means such as a memory, storage, I / O, and the like. In this case, the function of the control unit 270 is realized by the processor executing the program stored in the memory or the storage. As the computer, a general-purpose personal computer may be used, or a built-in computer or a PLC (programmable logical controller) may be used. Alternatively, a part or all of the functions of the control unit 270 may be configured by a circuit such as an ASIC or FPGA. A control unit 270 may be provided for each film forming apparatus, or one control unit 270 may control a plurality of film forming apparatus.

(Configuration for mark detection)
On the outer upper part of the vacuum chamber 200, a camera 261 that performs optical imaging and generates image data is provided as an imaging means. The camera 261 takes an image through a window (not shown) provided in the vacuum chamber 200. Although the one-step alignment method is adopted in this embodiment, a two-step alignment method may be used. In that case, install a camera for the first alignment (rough alignment) with a low resolution but a wide field of view and a camera for the second alignment (fine alignment) with a narrow field of view but a high field of view. Align in the order of fine alignment.

The camera 261 in this embodiment is installed at a position where the corners of the substrate 10 and the mask 220 can be imaged. The imaging region of the camera 261 includes a substrate mark 104 on the substrate surface and a mask mark 224 on the mask surface. In this embodiment, four cameras 261 are provided so as to correspond to the four corners of the substrate 10 and the mask 220. However, the number and installation location of alignment marks, and the number, installation location and type of cameras are not limited thereto.

The control unit 270 analyzes the image data (photographed image) captured by the camera 261 and acquires the position information of the substrate mark 104 and the mask mark 224. For example, looking at the substrate mark 104, the image data acquired by imaging the imaging region 264 is analyzed by pattern matching processing to extract a shape that matches the model substrate mark 174.

Since the position of the camera 261 is fixed, any position in the image data captured in the range of the imaging region 264 can be converted into a coordinate value. Therefore, the position of the alignment mark detected in each captured image can be acquired as a coordinate value.
As a result, the distance and angle between the substrate mark 104 and the mask mark 224 can be calculated. The camera 261 is a mark detection device that acquires the position information of each alignment mark. Further, the camera 261 and the control unit 270 may be combined to form a mark detection device. The control unit 270 functions as the detection means of the present invention.

In this embodiment, the substrate marks are formed on the substrate by laser processing, and each mask alignment mark is formed on the mask by machining. However, the mark forming method is not limited to these, and can be selected according to the material and purpose.

(Configuration for alignment)
A substrate Z actuator 250, a clamp Z actuator 251 and a cooling plate Z actuator 252 are provided on the outer upper portion of the vacuum chamber 200. Each actuator is composed of, for example, a motor and a ball screw, a motor and a linear guide, and the like. An alignment stage 280 is further provided on the outer upper part of the vacuum chamber 200.
The board Z actuator 250 is a driving means for raising and lowering the entire board support unit 210 in the Z axis direction. The substrate Z actuator 250 can be said to be a vertical moving means included in the alignment means. The clamp Z actuator 251 is a driving means for opening and closing the holding mechanism of the substrate support unit 210. The cooling plate Z actuator 252 is a driving means for raising and lowering the cooling plate 230.

The alignment stage 280 is an alignment device that moves the substrate 10 in the XY direction and rotates it in the θ direction to change the position with the mask 220. The alignment stage 280 can be said to be an in-plane moving means included in the alignment means. The alignment stage 280 includes a chamber fixing portion 281 connected and fixed to the vacuum chamber 200, an actuator portion 282 for performing XYθ movement, and a connecting portion 283 connected to the substrate support unit 210. The alignment stage 280 and the substrate support unit 210 may be combined to form an alignment device. Further, the control unit 270 may be further added to the alignment stage 280 and the substrate support unit 210 to form an alignment device.

As the actuator unit 282, an actuator in which an X actuator, a Y actuator, and a θ actuator are stacked may be used. Further, a UVW type actuator in which a plurality of actuators cooperate may be used. Regardless of the type of actuator unit 282, the actuator unit 282 is driven according to the control signal transmitted from the control unit 270, linearly moves the substrate 10 in the X and Y directions, and rotates in the θ direction. The control signal indicates the operating amount of each XYθ actuator in the case of a stacking type actuator, and indicates the operating amount of each UVW actuator in the case of a UVW type actuator.

The alignment stage 280 moves the substrate support unit 210 by XYθ. In this embodiment, the position of the substrate 10 is adjusted, but the position of the mask 220 may be adjusted, or the positions of both the substrate 10 and the mask 220 may be adjusted.

The control unit 270 performs various operations based on the image data. At the time of normal alignment, the amount of movement of the substrate in the XYθ direction is calculated based on the amount of misalignment between the substrate mark 104 and the mask mark 224 detected by the mark detection device. Subsequently, the control unit 270 converts the calculated movement amount of the substrate or the like into the drive amount of the stepping motor, servomotor, or the like included in each actuator of the alignment stage 280, and generates a control signal. Further, if necessary, the sensor signal from the alignment stage 280 is received and feedback control is performed.

(Processing flow)
The flow of processing will be described with reference to the drawings. FIG. 5 is a flow chart showing the mark detection process in this embodiment and the subsequent steps.

Further, FIG. 6 is a plan view showing a substrate mark and a model substrate mark used in this flow. The substrate mark 104 shown in FIG. 6A is actually formed on the substrate 10, and is shown in FIG. 4 (a).
It is the same as a). In the cross-shaped substrate mark 104 in which two lines (vertical line and horizontal line) intersect, the vertical line and the horizontal line have a thickness of the first region 104t and a second region 104m, respectively, due to the characteristics of laser processing. (The thickness of the second area 104m is almost constant). Here, the length h1 of the vertical line and the length w1 of the horizontal line of the substrate mark 104 are used, of which the length h2 of the second region 104m of the vertical line and the length w2 of the second region 104m of the horizontal line are used.

On the other hand, the cross shape where the vertical line model and the horizontal line model shown by the solid line in FIG. 6B intersect is smaller than the conventional model board mark 174 used in this flow (length of the vertical line model and the horizontal line model). (Short), modified model board mark 176. The modified model board mark 176 has the length h2 of the vertical line model and the length w2 of the horizontal line model, as in the second region 104m. That is, the modified model substrate mark 176 is an image that is linear and the length of the line corresponds to the second region of the substrate mark 104. The thickness (width) of the vertical line and the horizontal line is the same as the thickness of the second region 104 m. In this embodiment, the modified model board mark 176 replaces the model board mark 174 and is used as a model image.

In this flow, the mask 220 is carried from the mask stock chamber 120 into the film forming chamber 110 and supported by the mask stand 221 and the substrate 10 is carried from the pass chamber 150 into the film forming chamber 110 and supported by the substrate support unit 210. Start from the state where it was done.

In step S101, the substrate support unit 210 moves the substrate 10 in the vertical direction, and the distance between the substrate 10 and the mask 220 in the Z direction is set within the focus range of the camera 261 to the substrate mark 104 of the substrate 10 and the mask mark 224 of the mask 220. Is the alignment distance including. In this embodiment, the substrate 10 moves in the XY θ direction in the XY plane while the substrate 10 and the mask 220 maintain the alignment distance.
In step S102, the camera 261 captures the imaging region 264 and generates image data.

In step S103, the control unit 270 analyzes the image data and detects the substrate mark 104. Here, the pattern matching method is used as the alignment mark recognition method. The pattern matching method is a method of recognizing an alignment mark by determining the correlation between the pattern shape of the model mark stored in the memory of the control unit 270 in advance and the shape of the alignment mark in the image. The method is not limited to this as long as the mark can be identified, and for example, an edge detection method may be used.

Here, a characteristic method in this flow will be described. As described above, when the first region 104t of the substrate mark 104 is bulged (the thickness of the line of the first region is larger than the thickness of the line of the second region other than the vicinity of the end portion). (Case), when image processing using the model board mark 174 having the same size as the board mark 104 is performed, the recognition accuracy is lowered. Therefore, in the modified model board mark 176 of FIG. 6B, the overall size is about the same as the second region 104m of the board mark 104. Therefore, in the whole of the modified model board mark 176, the thickness of the tip matches the actual board mark 104. In other words, the control unit 270 in this flow attempts to extract a figure having a high degree of correlation with the modified model board mark 176 from the image pickup area 264. As a result, it becomes possible to detect the second region 104 m.

The control unit 270 generates data in which the area 178 deleted from the model board mark 174 is added to the detected second area 104m, and stores the data as the position information of the board mark 104 in the memory. However, the control unit 270 may use the second region 104m as it is as a substrate mark. In that case, in the determination process described later, mark comparison is performed on the premise of the size and position of the second area 104 m.

In step S104, the control unit 270 detects the mask mark 224 from the image data and stores the position information in the memory. Here, too, any method such as a pattern matching method or an edge detection method can be adopted.

In step S105, the control unit 270 compares the coordinate information of the board mark 104 stored in the memory with the coordinate information of the mask mark 224. Then, if the condition that the positional relationship such as the distance and the angle between the two is within a predetermined allowable range is satisfied, it is determined that the alignment is completed. On the other hand, when the positional relationship is out of the allowable range, the process proceeds to step S106, and the substrate 10 is moved in the plane in the XYθ direction based on the amount of deviation from the ideal positional relationship. By repeating this process, the relationship between the substrate 10 and the mask 220 falls within a predetermined range.

In step S107, the substrate support unit 210 operates to bring the substrate 10 into contact with the mask 220. For example, the substrate Z actuator 250 lowers the substrate 10 and places it on the mask 220.

In step S108, the evaporation source 240 as a film forming source is heated, and the film forming material is formed on the substrate 10 via the mask 220. As a result, a film having a shape corresponding to the mask pattern is formed on the substrate. The above flow completes the film formation process inside the chamber.

As described above, in this embodiment, when the substrate mark whose end is swollen or deformed due to the characteristics of laser processing is detected, the region which is one size smaller than the substrate mark and corresponds to the deformed portion of the substrate mark is deleted. Use the modified model board mark. As a result, the detection process can be performed without being affected by the deformed portion of the substrate mark, so that the accuracy of mark detection is improved and good alignment is possible.

<Example 2>
In this embodiment, an example in which the shape of each alignment mark used on the substrate 10 is different from that of the first embodiment will be described.

FIG. 7A shows the substrate mark 104 according to this embodiment. As described above, due to the influence of laser processing, the first region 104t of one linear substrate mark 104 has a bulging shape as compared with the second region 104m.
FIG. 7B shows a model board mark 174 used when the board mark 104 of this embodiment is detected by a conventional method. When the length (h1) of the model board mark 174 is matched with the length of the board mark 104 in this way, the detection accuracy of the board mark 104 by the pattern matching method may decrease because the first region 104t exists. be.

Therefore, in this embodiment, the detection is performed using the modified model board mark 176 as shown in FIG. 7 (c). Since the length h2 of the single linear modified model substrate mark 176 corresponds to the length of the second region 104 m whose thickness is within a certain range, there is little possibility that the detection accuracy will deteriorate.

<Example 3>
Subsequently, an example in which the method of creating the modified model board mark 176 and the method of applying the modified model board mark 176 are different will be described. This embodiment is characterized in that a plurality of types of modified model board marks 176 are created, and appropriate ones are selected and used according to the board mark 104.

8 (a) and 8 (b) are modified model board marks 176 having different widths (horizontal line model lengths) and heights (vertical line model lengths) than FIG. 6 (b), respectively. be. Here, the degree of swelling or deformation of the first region 104t of the substrate mark 104 may be slightly different depending on the material of the substrate 10, the accuracy of laser processing, and the like. Therefore, the modified model board mark 176 shown in FIG. 6B may overlap the bulging portion. On the contrary, if the modified model board mark 176 shown in FIG. 6B is too small compared to the second region 104m, the accuracy of mark detection may decrease.

Therefore, in addition to the one shown in FIG. 6 (b), the control unit 270 of the present embodiment has a longer vertical line model and horizontal line model than the modified model board mark 176 in FIG. 6 (b) in FIG. 8 (a). ), And the length of the vertical line model and the horizontal line model are shorter than those shown by the modified model board mark 176 in FIG. 6 (b). As shown in FIG. 8 (b), a plurality of modified model boards having different sizes. Prepare the mark 176 and save it in the memory. Then, the substrate mark 104 in the captured image is compared with each of the plurality of modified model substrate marks 176, and the one having the most appropriate size to be compared with the mark from which the bulge of the first region 104t has been removed is selected. This makes it possible to prevent a decrease in mark detection accuracy. The user may manually select which modified model board mark 176 should be selected when the mark is detected by looking at the captured image, or the control unit 270 may select an appropriate one.

In this embodiment, the length of the vertical line model and the length of the horizontal line model of the modified model board mark 176 are matched, but the present invention is not limited to this. For example, if the degree of deformation of the edges of the board mark tends to vary from edge to edge, change the vertical and horizontal model lengths of the modified model board mark and the intersection position of the vertical and horizontal models accordingly. You may.
Further, even when a shape other than the cross shape, for example, one linear substrate mark is used, a plurality of types of modified model substrate marks having different sizes may be prepared as described in this embodiment.

<Example 4>
In this embodiment, another example of the method of creating the modified model board mark 176 will be described.
In each of the above embodiments, the size and shape of the modified model board mark 176 are determined based on the design value of the board mark 104. However, based on the image data of the substrate mark 104 acquired by the camera 261 as a photographing means, the control unit 270 deletes the bulge and the deformed portion from the substrate mark 104 to create the modified model substrate mark 176. You may.
According to this embodiment, if the boundary between the substrate mark 104 and the surroundings (background) acquired by imaging is not clear, it may not be possible to create a model image as precise as in each of the above embodiments, but the actual substrate. Mark detection and alignment can be performed based on the mark 104.

261: Camera, 270: Control unit

The present invention adopts the following configuration. That is,
A mark detection device that detects alignment marks.
An imaging means for obtaining a captured image by photographing an area including the alignment mark,
A detection means for detecting the position of the alignment mark by comparing the captured image with the model image is provided.
The alignment mark includes a linear portion and includes a linear portion.
The detection means compares the portion of the alignment mark excluding the end of the linear portion with the model image.
It is a mark detection device characterized by this.
The present invention also adopts the following configuration. That is,
A mark detection device that detects alignment marks.
An imaging means for obtaining a captured image by photographing an area including the alignment mark,
A detection means for detecting the position of the alignment mark by comparing the captured image with the model image is provided.
The alignment mark includes a linear portion and includes a linear portion.
The model image includes a linear model portion corresponding to the linear portion of the alignment mark.
The length of the linear model portion of the model image is shorter than the length of the linear portion of the alignment mark.
It is a mark detection device characterized by this.
The present invention also adopts the following configuration. That is,
It is a mark detection method that detects alignment marks.
The shooting process of shooting the area including the alignment mark to obtain a shot image, and
It has a detection step of comparing the captured image with the model image and detecting the position of the alignment mark.
The alignment mark includes a linear portion and includes a linear portion.
The detection step includes a comparison step of comparing the portion of the alignment mark excluding the end of the linear portion with the model image.
This is a mark detection method characterized by the above.
The present invention also adopts the following configuration. That is,
It is a mark detection method that detects alignment marks.
The shooting process of shooting the area including the alignment mark to obtain a shot image, and
It has a detection step of comparing the captured image with the model image and detecting the position of the alignment mark.
The alignment mark includes a linear portion and includes a linear portion.
The model image includes a linear model portion corresponding to the linear portion of the alignment mark.
The length of the linear model portion of the model image is shorter than the length of the linear portion of the alignment mark.
This is a mark detection method characterized by the above.

Claims (8)

The substrate having a substrate mark which is a linear mark and whose thickness of the line in the first region near the end of the line is larger than the thickness of the line in the second region other than near the end of the line. In the mark detection device that detects the board mark,
A shooting means for shooting an image of the imaging area including the board mark, and
A detection means for detecting the position of the substrate mark by comparing the photographed image captured by the photographing means with the model image.
The mark detection device is characterized in that the model image is linear and the length of the line corresponds to the second region of the substrate mark. The substrate mark is a cross-shaped mark in which a vertical line and a horizontal line intersect, and the vertical line and the horizontal line have the first region and the second region, respectively.
The model image is a cross-shaped image in which a vertical line model having a length corresponding to the second region of the vertical line and a horizontal line model having a length corresponding to the second region of the horizontal line intersect. The mark detection device according to claim 1, wherein the mark detection device is provided. The mark according to claim 2, wherein the detection means detects the position of the substrate mark using the model image selected from the plurality of model images having different lengths of the vertical line model or the horizontal line model. Detection device. The mark detection device according to any one of claims 1 to 3, wherein the substrate mark is formed on the substrate by laser processing. The mark detection device according to claim 4, wherein the substrate is a wafer substrate. The mark detection device according to any one of claims 1 to 5, wherein the model image is generated based on a design value of the substrate mark. The mark detection device according to any one of claims 1 to 5, wherein the model image is generated based on an image of the substrate mark included in the photographed image acquired by the photographing means. A mark detection device that detects the substrate mark formed on the substrate and the mask mark formed on the mask,
An alignment means for aligning the substrate and the mask based on the positions of the substrate mark and the mask mark,
Have,
The alignment device according to any one of claims 1 to 7, wherein the mark detection device is the mark detection device.

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