JP7817892B2 - Alignment apparatus, film forming apparatus, and alignment method - Google Patents

Description

The present invention relates to an alignment device, a film formation device equipped with the alignment device, and an alignment method.

Organic electroluminescent (EL) display devices are well known as flat panel display devices. The organic EL elements that make up these display devices have a basic structure in which a functional layer is formed between two opposing electrodes (a cathode electrode and an anode electrode), with a light-emitting layer, an organic material layer that emits light. The functional and electrode layers of an organic EL element are formed in a film-forming device by depositing the materials that make up each layer onto a substrate such as glass through a mask.

When a film formation device is forming a film, the image obtained by photographing the substrate using an imaging device may be used for substrate alignment, inspection, and other purposes. Patent Document 1 discloses a configuration in which an edge image of a substrate held by a carrier is captured using illumination light from a light source, and the substrate is aligned with the carrier based on positional information of the substrate obtained from the edge image. In this configuration, the edge of the substrate is detected from the edge image to obtain positional information of the substrate.

Japanese Patent Application Laid-Open No. 2020-003469

However, if there is dirt or scratches on the substrate or the holding means, such as a carrier, that holds the substrate, the dirt or scratches may be mistakenly recognized as the edge of the substrate when detecting the edge of the substrate. Misrecognition of the edge can lead to problems such as reduced alignment accuracy between the substrate and the holding means, and ultimately damage to the substrate during transport.

The present invention was made in consideration of the above-mentioned problems, and aims to provide technology for detecting the edge of a substrate with high accuracy in an alignment device that aligns the substrate with a holding means.

The alignment device of the present invention comprises:
An alignment apparatus for aligning a substrate with respect to a holding means for holding the substrate, comprising:
an imaging means for capturing an edge image including the edge of the substrate held by the holding means;
an edge detection means for setting a detection area within the edge image and detecting an edge of the substrate from within the detection area along a reference direction of the detection area;
an alignment means for aligning the substrate with respect to the holding means based on the edge detected by the edge detection means;
Equipped with
The edge detection means is characterized in that it determines whether the line segment is an edge of the substrate based on the length of the detection area in the reference direction and the length of the line segment along the reference direction detected within the detection area.
Further, the alignment method of the present invention includes:
an imaging step of capturing an edge image including an edge of the substrate held by a holding means for holding the substrate;
a region setting step of setting a detection region within the edge image;
a line segment detection step of detecting a line segment along a reference direction of the detection area within the detection area;
a length acquisition step of acquiring the length of the line segment;
an edge detection step of detecting an edge of the substrate from the edge image based on the length of the line segment and the length of the detection area in the reference direction;
an alignment step of aligning the substrate with respect to the holding means based on the edge of the substrate detected in the edge detection step;
The present invention is characterized by comprising:

The present invention provides technology for detecting the edge of a substrate with high accuracy in an alignment device that aligns the substrate with a holding means.

FIG. 1 is a schematic diagram illustrating the configuration of a film forming apparatus. FIG. 2 is a schematic configuration diagram of a substrate lifting device provided in a carrier transfer chamber. 10A and 10B are diagrams showing captured images and edge images of a substrate and a substrate carrier; 1A and 1B are diagrams illustrating a method for detecting an edge of a substrate. FIG. 10 is a flow diagram of edge detection of a substrate. FIG. 10 is a flowchart of edge detection of a substrate according to a modified example. FIG. 2 is a schematic diagram of a film formation chamber. FIG. 1 is a diagram illustrating a configuration of an electronic device.

The following describes in detail the embodiments of the present invention, by way of example, with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in these embodiments should be modified as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, it is not intended that the scope of the present invention be limited to the following embodiments.

The present invention is suitable for forming a thin film of a film-forming material on the surface of a substrate or other film-forming object by vapor deposition or sputtering while the object is being transported. The present invention can be understood as a substrate transport apparatus, a control method thereof, or a substrate transport method. The present invention can also be understood as a film-forming apparatus, a control method thereof, or a film-forming method. The present invention can also be understood as an electronic device manufacturing apparatus or an electronic device manufacturing method. The present invention can also be understood as a program for causing a computer to execute the control method, or a storage medium storing the program. The storage medium may be a non-transitory storage medium readable by a computer.

The present invention can be applied to, for example, a film formation apparatus that forms a thin film of a film formation material on the surface of a transported object to be filmed, such as a substrate, by vapor deposition or sputtering, and is preferably applied to an apparatus that forms a thin film (material film) of a desired pattern by vacuum vapor deposition. The substrate material can be any material, such as glass, a polymeric film, a silicon wafer, or a metal. The substrate may be, for example, a glass substrate on which a film such as polyimide is deposited. The vapor deposition material may also be any material, such as an organic material or a metallic material (metal, metal oxide, etc.). In addition to the vacuum vapor deposition apparatus described below, the present invention can also be applied to film formation apparatuses including sputtering apparatuses and CVD (Chemical Vapor Deposition) apparatuses. The technology of the present invention is as follows:
Specifically, the present invention can be applied to manufacturing apparatuses for organic electronic devices (e.g., organic light-emitting elements, thin-film solar cells), optical components, etc. Among these, a manufacturing apparatus for organic light-emitting elements that forms an organic light-emitting element by evaporating a deposition material and depositing it on a substrate through a mask is one preferred application example of the present invention. Below, the present invention will be described using an example in which it is applied to an electronic device manufacturing apparatus, but the alignment apparatus of the present invention is not limited to this and can be applied to the various manufacturing apparatuses mentioned above.

(Example)
<Film forming equipment>
FIG. 1 is a plan view showing the schematic configuration of a film formation apparatus including an alignment apparatus according to an embodiment of the present invention. Here, a film formation apparatus in a manufacturing line for organic EL displays will be described. When manufacturing an organic EL display, a substrate of a predetermined size is carried into the film formation apparatus, and organic EL and metal layer films are formed. After film formation, the substrate is carried out to a post-process where it undergoes post-processing such as cutting the substrate.

In this embodiment, an inline-type film formation apparatus will be described as an example. In an inline-type film formation apparatus, multiple chambers are arranged in a row, and the substrate 200, substrate carrier 100, and mask M are transported sequentially into each chamber, where various processes are performed. Transport rollers and linear motors are used as transport means to transport the substrates, etc. Multiple transport rollers are arranged on both sides of the transport path along the transport direction, and are rotated by the driving force of an AC servo motor (not shown), transporting the substrate carrier 100 and mask M into and out of each chamber. Each chamber is configured to be able to create a vacuum atmosphere or an inert gas atmosphere for each individual chamber, or for each of multiple adjacent chambers. The film formation apparatus is equipped with a vacuum pump (not shown) to maintain the vacuum state inside the vacuum container.

The film formation apparatus to which the alignment device of the present invention is applied is not limited to an inline type, but may also be a cluster type film formation apparatus. In a cluster type film formation apparatus, a film is formed on a substrate while it is transported between multiple chambers arranged around a transport robot.

In Figure 1, of the multiple chambers, only those chambers performing representative processing are indicated by the symbol R, and other chambers are omitted with black dots. Also in Figure 1, thin solid arrows indicate the transport path for the substrate carrier 100, thin dashed arrows indicate the transport path for the substrate 200, and thick solid arrows indicate the transport path for the mask M. The operation of the equipment provided in each chamber is controlled by a control unit C such as a computer. The control unit C can be provided individually for each piece of equipment, or a common control unit C can be provided for multiple pieces of equipment. In general, the fact that various operations are controlled by a control unit is a well-known technique. The control unit C can be, for example, an information processing device or processing circuit equipped with computing resources such as a processor and memory.

First, the substrate carrier 100 and substrate 200 are sent to the substrate loading chamber R1, where the substrate 200 is held on the upper side of the substrate carrier 100. The substrate carrier 100, which serves as a holding means for holding the substrate 200, is positioned within the substrate loading chamber R1 with its substrate holding surface facing vertically upward. The substrate 200 brought into the substrate loading chamber R1 is placed on the substrate holding surface of the substrate carrier 100 so that the surface on which the film is to be formed faces vertically upward. During this placement, the film forming device images the substrate 200 to obtain position information, and performs position adjustment (first alignment) so that the substrate 200 is in a predetermined position on the substrate carrier 100. The substrate carrier 100 and the substrate 200 held by the substrate carrier 100 are then transported to the reversal chamber R2.

The reversing chamber R2 is provided with an inverting mechanism that inverts the orientation of the substrate holding surface of the substrate carrier 100 from a vertically upward direction to a vertically downward direction. In the inverting chamber R2, the substrate carrier 100 and the substrate 200 are rotated 180° upside down so that the substrate 200 is held on the lower side of the substrate carrier 100.

Furthermore, the mask M is transported to the reversal chamber R2 via a route separate from the transport route of the substrate carrier 100. In the reversal chamber R2, the substrate carrier 100, which holds the substrate 200 on its underside, is placed on top of the mask M. The substrate 200 held by the substrate carrier 100 is then transported to the film formation chamber R3 together with the mask M that has been sent to the reversal chamber R2. Note that the rotation of the substrate carrier 100, the merging with the mask M, and the placement on the mask M may each be performed in separate chambers.

An alignment device is located in the reversal chamber R2, which aligns the substrate carrier 100 (and the substrate 200 held therein) with the mask M. The alignment device places the substrate carrier 100 on the mask M, ensuring that the substrate 200 and mask M have a predetermined positional relationship in the in-plane direction of the film-forming surface of the substrate 200. When the substrate carrier 100 is placed on the mask M in the reversal chamber R2, the film-forming device images the substrate 200 and mask M to obtain position information and adjusts the positions of the substrate 200 and mask M in the in-plane direction (second alignment).

Next, in the film formation chamber R3, a thin film is formed on the surface of the substrate 200 through a mask M with openings at the desired film formation positions, and then the substrate carrier 100, etc. is transported to the mask unloading chamber R4. Generally, multiple film formation chambers R3 are provided as shown in Figure 1 so that thin films can be formed using different materials. Therefore, typically, a single transport of the substrate 200 results in film formation processing in one specific film formation chamber R3.

After film formation, the substrate 200 held by the substrate carrier 100 is lifted from the mask M in the mask unloading chamber R4. Masks M that have been used a predetermined number of times are unloaded from the mask unloading chamber R4 to the outside of the apparatus. The substrate 200 held by the substrate carrier 100 and masks M to be used again are transported from the mask unloading chamber R4 to the relay chamber R5. The masks M in the relay chamber R5 are transported toward the reversing chamber R2. A mask stocker may be installed on the production line to store multiple masks M and unload them as needed. The substrate carrier 100 and substrate 200 in the relay chamber R5 are inverted in an unshown reversing chamber so that the film-forming surface of the substrate 200 and the substrate-holding surface of the substrate carrier 100 are facing vertically upward, and then transported to the substrate peeling chamber R6.

Then, in the substrate removal chamber R6, the substrate 200 is removed from the substrate carrier 100. The substrate carrier 100 is then either transported outside the film formation apparatus or transported back to the substrate loading chamber R1. The substrate 200 removed from the substrate carrier 100 is then removed to the outside. Note that the present invention is not limited to the deposit-up configuration shown in Figure 1, and may also have a deposit-down configuration or a side deposit configuration.

<Operation of placing substrate on substrate carrier>
The operation of the substrate lifting device disposed in the substrate loading chamber R1 to make the substrate carrier 100 hold the substrate 200 will be described with reference to Figures 2(a) and 2(b). Figure 2(a) is a diagram showing the state in which the substrate 200 carried into the carrier transfer chamber 300 is supported by the lifting mechanism 400. Figure 2(b) is a diagram showing the state in which the substrate 200 is held by the substrate carrier 100 in the carrier transfer chamber 300.

First, the general configuration of the substrate lifting device will be described. The substrate lifting device includes a carrier transfer chamber 300, a lifting mechanism 400, and a clamp rotation mechanism 500 as a clamp driving means. Note that the substrate lifting device may be provided with a plurality of lifting mechanisms 400 having similar configurations.

The carrier transfer chamber 300 is equipped with an opening 321 through which the substrate 200 passes and a substrate gate valve 322 that can open and close this opening 321. Although not shown, the carrier transfer chamber 300 also has an opening through which the substrate carrier 100 passes and a carrier gate valve that can open and close this opening. Substrates 200 and substrate carriers 100 are transported into and out of the carrier transfer chamber 300 via these openings by a transport means such as a robot hand.

The carrier transfer chamber 300 is also provided with a carrier support member 330 that supports the substrate carrier 100 when the substrate 200 is placed on the substrate carrier 100. This carrier support member 330 supports the outer periphery of the substrate carrier 100 so as not to interfere with the operation of the support pins provided on the lifting mechanism. Alternatively, the carrier support member 330 may be provided with an opening in the area through which the support pins pass. The substrate loading chamber R1 (carrier transfer chamber 300) may also be provided with transport rollers for transporting the substrate carrier 100. In this case, the transport rollers can support the substrate carrier 100 when the substrate 200 is placed on the substrate carrier 100.

Furthermore, the carrier transfer chamber 300 is provided with an imaging means 350 (photographing means). Although only one imaging means 350 is shown in each figure, multiple imaging means 350 are generally provided. The control unit C can adjust the positions (alignment) of the substrate carrier 100 and the substrate 200 by acquiring position information from images of the substrate carrier 100 and the substrate 200 captured by the imaging means 350. The imaging means 350 is arranged in the carrier transfer chamber 300 so that the field of view includes at least a portion of the sides and edges of the substrate 200, in order to perform alignment based on edge images of the substrate 200.

The imaging means 350 can also serve as a discrimination means for discriminating the type of substrate carrier 100 or the type of substrate 200. For example, various marks are attached to the substrate carrier 100 according to the type, and the type of substrate carrier 100 can be discriminated from the marks imaged by the imaging means 350. The imaging means 350 used for alignment and the imaging means 350 serving as discrimination means may be provided separately, or one of the multiple imaging means 350 generally provided for alignment purposes can also serve as discrimination means.

In this embodiment, the lifting mechanism 400 is configured so that only the support pin 411 is inserted into the carrier transfer chamber 300, and the clamp rotation mechanism 500 is configured so that only the push-in pin 511 is inserted into the carrier transfer chamber 300. This prevents lubricants, wear debris, and the like from entering the carrier transfer chamber 300. The entire substrate lifting device may be located in the substrate loading chamber R1, or the carrier loading chamber 300 described above may correspond to the substrate loading chamber R1. In the latter case, most of the components of the lifting mechanism (components other than the support pin 411) and most of the components of the clamp rotation mechanism 500 (components other than the push-in pin 511) will be located outside the substrate loading chamber R1.

The lifting mechanism 400 includes a plurality of support pins 411, a first plate 410 that supports the plurality of support pins 411, and a ball screw mechanism 420 that serves as a first lifting means for raising and lowering the first plate 410. The plurality of support pins 411 that serve as support means for supporting the substrate 200 are configured to be able to abut the substrate 200 from below in the vertical direction, and the substrate 200 is raised and lowered by the support pins 411 moving up and down within the carrier transfer chamber 300. Note that while a ball screw mechanism is used as the lifting means for raising and lowering the first plate 410 in this example, other known technologies such as a rack and pinion system can also be used as the lifting means.

The substrate lifting device also includes an alignment mechanism 430 as alignment means that adjusts the position of the substrate 200 relative to the substrate carrier 100 by moving multiple support pins 411 in a direction perpendicular to the direction in which the substrate 200 is raised and lowered. In this embodiment, the direction in which the substrate 200 is raised and lowered is vertical. Therefore, the alignment mechanism 430 is configured to be able to move the multiple support pins 411 horizontally. The mechanism for moving the support pins 411 in the alignment mechanism 430 can employ various known technologies, such as a ball screw mechanism or a rack and pinion mechanism.

The alignment mechanism 430 configured as described above can move the substrate 200 placed on multiple support pins 411 in the horizontal direction, thereby adjusting the position of the substrate 200 relative to the substrate carrier 100.

The clamp rotation mechanism 500 includes a plurality of push-in pins 511, a clamp plate 510 that supports the plurality of push-in pins 511, and a ball screw mechanism 520 that raises and lowers the clamp plate 510. The clamp rotation mechanism 500 rotates the clamps 110 that are provided on the substrate carrier 100 to hold the substrate 200. The substrate carrier 100 is provided with a plurality of clamps 110, and the push-in pins 511 are provided at positions corresponding to the clamps 110. Note that while a ball screw mechanism is used as the lifting means for raising and lowering the clamp plate 510, other known technologies such as a rack and pinion system can also be used as the lifting means.

As described above, the substrate carrier 100 includes a plurality of clamps 110 for holding substrates 200. The clamps 110 are rotatably mounted on the substrate carrier 100 while being biased by a biasing member in a first rotational direction, which is a direction in which the substrate 200 to be held by the substrate carrier 100 is clamped. When the substrate 200 is placed on the substrate carrier 100 or when the substrate 200 is removed from the substrate carrier 100, the clamps 110 are biased by the push-in pins 511 and rotate in a second rotational direction. Note that in FIG. 2(a), the left clamp 110 is rotatably mounted on the substrate carrier 100 while being biased in the clockwise direction, and the right clamp 110 is rotatably mounted on the substrate carrier 100 while being biased in the counterclockwise direction.

Next, we will explain in detail the movement of the substrate lifting device when the substrate 200 is held by the substrate carrier 100 in the carrier transfer chamber 300. After being loaded into the carrier transfer chamber 300, the substrate 200 is supported by multiple support pins 411 at a position above the substrate carrier 100.

While the substrate 200 is supported by the multiple support pins 411, the imaging means 350 captures an image of the substrate 200. The control unit C then obtains positional information for the substrate 200 based on the image captured by the imaging means 350, and determines the positional relationship between the substrate 200 and the substrate carrier 100.

Then, the control unit C moves the substrate 200 in the X-axis and Y-axis directions using the alignment mechanism 430 to adjust the position of the substrate 200 relative to the substrate carrier 100. This positions the substrate 200 facing the substrate carrier 100 at a predetermined placement position.

Thereafter, the support pins 411 are lowered by the lifting mechanism 400, and the tips of the multiple support pins 411 move below the lower surface of the substrate carrier 100. During this process, the substrate 200 is placed on the substrate carrier 100. The substrate carrier 100 is provided with multiple suction pads, and the substrate 200 is held by the multiple suction pads. However, simply placing the substrate 200 on the substrate carrier 100 may not provide sufficient suction to the suction pads, so it is also preferable to carry out a step of pressing the substrate 200 downward to more reliably hold the substrate 200 by the suction pads.

When the support pins 411 are lowered, the clamps 110 are pressed by the pusher pins 511 so that the substrate 200 can be placed on the substrate carrier 100. After the substrate 200 is placed on the substrate carrier 100, the clamp rotation mechanism 500 lowers the clamp plate 510. This causes the pusher pins 511 to separate from the clamps 110, which then rotate in the first rotation direction, clamping the substrate 200 between the substrate carrier 100. As shown in FIG. 2(b), the substrate 200 is then held by the substrate carrier 100. The substrate 200 held in this manner is then transported together with the substrate carrier 100 from the carrier transfer chamber 300 and transported to the reversal chamber R2.

<Alignment of the substrate to the substrate carrier>
The alignment and placement of the substrate 200 on the substrate carrier 100 in the alignment device provided in the film deposition apparatus according to this embodiment will be described in more detail below.

As described above, the control unit C obtains position information for the substrate 200 based on images captured by the imaging means 350 in the substrate loading chamber R1, and determines its positional relationship with the substrate carrier 100. The control unit C then moves the substrate 200 in the X-axis and Y-axis directions using the alignment mechanism 430. This positions the substrate 200 facing the substrate carrier 100 at a predetermined loading position, and then the lifting mechanism 400 places the substrate 200 on the substrate carrier 100.

In this embodiment, the imaging means 350 is an optical imaging device that can control the amount of illumination light from the light source, shutter speed, gain value, etc. using a control unit C. The control unit C can adjust the image obtained by controlling at least one of the amount of light, shutter speed, and gain value. Therefore, the control unit C functions as a parameter adjustment means.

In this embodiment, the control unit C analyzes the image captured by the imaging means 350 to recognize the edges of the substrate 200, and acquires position information for the substrate 200 based on the edges. The procedure for acquiring position information for the substrate 200 from the image captured by the imaging means 350 will be described with reference to Figures 3(a) to 3(d). Figure 3(a) shows an image captured by the imaging means 350. Figure 3(b) shows an edge image created by the control unit C based on the image captured by the imaging means 350. Figure 3(c) shows how the edge of the substrate 200 has been properly detected in the edge image. Figure 3(d) shows, as a comparative example, how a scratch on the substrate carrier 100 has been erroneously recognized as the edge of the substrate 200 in the edge image.

The imaging means 350 of this embodiment images one of the four corner edge portions of the substrate 200, which has a substantially rectangular surface, and Figure 3(a) shows the inside of the viewing angle 351. In Figure 3(a), which shows the image captured by the imaging means 350, areas made of similar materials are shown in similar colors. In other words, the inside of the substrate carrier 100 and the inside of the substrate 200 each have similar pixel values.

At the time of capturing the image in FIG. 3A, the substrate 200 is positioned vertically above the substrate carrier 100. Therefore, when viewed from the imaging device 350 disposed above the substrate loading chamber R1, the substrate 200 overlaps a portion of the substrate carrier 100. Within the range of the viewing angle 351, the substrate 200 has an edge 210A parallel to the substrate transport direction and an edge 210B perpendicular to the substrate transport direction. Furthermore, in this example, the corners of the substrate 200 are partially missing (corner edges 210C). Note that carrier marks may be formed on portions of the substrate carrier 100. Also, FIG. 3A illustrates an image captured when the substrate 200 is located at a predetermined reference position when the imaging device 350 captures the substrate 200. Here, the reference position is a target position in the design. The reference position of the substrate 200 is set so that the edges 210A and 210B of the substrate 200 fall within the viewing angle 351 even if the position of the substrate 200 is slightly deviated from the reference position.

Controller C performs image processing on the captured image to create an edge image. Existing edge extraction processing can be used to create the edge image; for example, an edge detection filter such as a differential filter can be applied to the image data to create the edge image. Noise reduction processing such as smoothing may be performed as needed during edge extraction. As in the edge image shown in Figure 3(b), areas where there is a large change in pixel value from adjacent pixels are extracted as edges. In other words, the transition areas between non-edge areas and edges are detected by differences in contrast. As a result, the edge image shows the transition areas between non-edge areas and edges with emphasis on edges 210A, 210B and corner edges 210C that form the outline of substrate 200.

If the edges of the substrate 200 are properly detected, the control unit C obtains a first reference line 220A along the edge 210A in the edge image and a second reference line 220B along the edge 210B, as shown in Figure 3(c). The control unit C obtains in-plane position information of the substrate 200 from the first reference line 220A and second reference line 220B that intersect with each other. The substrate 200 is then aligned with the substrate carrier 100 based on this position information. In this way, in this embodiment, position information of the substrate is obtained from the position information of the two edges of the substrate.

When creating an edge image, if there are scratches or stains on the substrate 200 or the substrate carrier 100, the scratches or stains may be highlighted in the edge image, similar to the edges of the substrate 200. This can result in the scratch or stain being mistakenly recognized as an edge during edge detection, affecting alignment. For example, as in the comparative example shown in Figure 3(d), if there is a scratch Sc on the substrate carrier 100, the first reference line 220A may be created along the scratch Sc instead of the edge 210A. If the scratch Sc is mistakenly recognized as an edge and the first reference line 220A is created in an incorrect position, alignment will be performed based on incorrect position information for the substrate 200. If alignment is not performed properly, the substrate 200 may not be placed in the correct position relative to the substrate carrier 100, which can cause various problems, such as cracking of the substrate when transported by the transport means.

<Edge detection method>
In the present invention, in order to improve the accuracy of edge detection of the substrate 200, a detection area is set within the edge image, and a determination is made as to whether a detected line segment is an edge of the substrate based on the length of the line within the detection area. Details of the edge detection method within the edge image of the present invention will be described below with reference to Figures 4(a) to (d), using an example in which there is a scratch Sc on the substrate carrier 100.

When the control unit C, which functions as edge detection means, creates an edge image, it sets rectangular first and second detection areas T1 and T2 within the edge image, as shown in FIG. 4A. The first detection area T1 is an area for detecting the edge 210A, and is set so that the edge 210A is included within the area when the substrate 200 is positioned at the reference position. Similarly, the second detection area T2 is an area for detecting the edge 210B, and is set so that the edge 210B is included within the area. When the extension direction of the edge 210A when the substrate 200 is positioned at the reference position is defined as a first direction D1, and the extension direction of the edge 210B is defined as a second direction D2, the first detection area T1 has a rectangular shape that is long in the second direction D2, and the sides of the first detection area T1 are parallel to either the first direction D1 or the second direction D2. On the other hand, the second detection area T2 has a rectangular shape that is long in the first direction D1, and the sides of the second detection area T2 are parallel to the first direction D1 or the second direction D2. By setting the detection areas in this manner, the desired edge is included within the detection area even if the substrate 200 is slightly displaced from the reference position during imaging. Note that the shape and size of each detection area can be changed appropriately to suit the substrate or substrate carrier. Below, the edge detection method according to the present invention will be described using an example in which part of the scratch Sc is included within the first detection area T1.

After setting the detection area, the control unit C detects line segments within the detection area along the reference direction of the detection direction. Here, the reference direction of the detection area is set along the edge of the substrate 200 to be detected. Furthermore, a slight inclination of the line segments with respect to the reference direction is permitted, and if the angle between the reference direction and the line segment is equal to or greater than a predetermined value, the line segment is not detected. In this embodiment, the control unit C divides the detection area in the detection direction and detects line segments within each divided area, starting from the outermost divided area of the substrate 200. As shown by the arrows in Figure 4(b), the detection direction in the first detection area T1 is parallel to the second direction D2, and the detection direction in the second detection area T2 is parallel to the first direction D1. That is, in the first detection area T1, a portion of the scratch Sc on the outer side of the substrate 200 is first detected as line segment L1a, not the edge 210A. Meanwhile, in the second detection area T2, a portion of the edge 210B is detected as line segment L2a. When detecting lines, even if there are slight breaks along the way, they may be considered unbroken and detected as a single line.

When a line segment is detected, the control unit C determines whether the detected line segment is an edge of the substrate 200 based on its length. Specifically, the control unit C calculates a score value SV, which is the ratio of the length of the detected line segment to the length (width) of the detection area in the reference direction. If the score value SV is equal to or greater than a predetermined value, the control unit C detects the line segment as an edge of the substrate 200. In this embodiment, if the score value is 80% or greater, the line segment is detected as an edge of the substrate 200. That is, the score value threshold for detecting a line segment as an edge of the substrate 200 is 80% in each of the first detection area T1 and the second detection area T2. Note that in this embodiment, the same threshold is set for the first detection area T1 and the second detection area T2. However, different thresholds may be set for each detection area, such as setting the first threshold for the first detection area T1 to 90% and the second threshold for the second detection area T2 to 80%.

As shown in Figure 2(b), in the first detection region T1, the length Q1 of the first detection region T1 in the first direction D1 is used to calculate the score value SV. By using the width in a direction roughly parallel to the extension direction of the edge 210A of the substrate 200 to calculate the score value SV, the threshold value for the score value SV can be set high, thereby reducing false edge recognition. When the control unit C detects a portion of the scratch Sc as a line segment L1a, it calculates a score value SV1a = P1a/Q1 [%] based on the length Q1 of the first detection region T1 in the first direction D1 and the length P1a of the line segment L1a in the first direction D1. If the score value SV1a is below the threshold, the control unit C determines that the line segment L1a is not an edge of the substrate 200 and begins detecting a new line segment along the detection direction. In this embodiment, the score value SV1a is 50%, and the control unit C determines that the line segment L1a is not an edge of the substrate 200.

When detection of a new line segment begins in the first detection region T1, a portion of the edge 210A is detected as a line segment L1b, as shown in FIG. 4C. Then, a score value SV1b = P1b/Q1 [%] is calculated from the length Q1 of the first detection region T1 in the first direction D1 and the length P1b of the line segment L1b in the first direction D1. Because the edge 210A extends across the first detection region T1, the score value SV1b is calculated as 100%. The controller C then determines that the score value SV1b is equal to or greater than the threshold value of 80%, and detects the line segment L1b as an edge of the substrate 200. Note that if the length of the detected line segment is equal to or greater than the length of the detection region in the reference direction and the score value is equal to or greater than 100%, the line segment may be detected as an edge, and detection and determination of subsequent line segments may not be performed.

In the second detection area T2, the length Q2 of the second detection area T2 in the second direction D2 is used to calculate the score. There are no scratches or stains in the second detection area T2, and a portion of the edge 210B is first detected as line segment L2a. Then, the score SV2a = P2a/Q2 [%] is calculated from the length Q2 of the second detection area T2 in the second direction D2 and the length P2a of the line segment L2a in the second direction D2. Because the edge 210A extends across the first detection area T1, the score SV1b is calculated as 100%. The control unit C then determines that the score SV2a is equal to or greater than the threshold value of 80%, and detects the line segment L2a as the edge of the substrate 200.

Based on the edges detected in each detection area through the above steps, the control unit C obtains position information for the substrate 200, namely, a first reference line 220A along edge 210A and a second reference line 220B along edge 210B, as shown in Figure 4(d). In other words, since position information for two sides of the surface of the substrate 200 is obtained, position information for the substrate 200 in the in-plane direction of the substrate 200 can be obtained.

In this embodiment, whether a line segment is an edge is determined based on the length of the line segment detected within the detection area, but the determination can also be made based on the angle and thickness of the line segment in addition to the length. Increasing the number of edge determination criteria in this way enables more accurate edge detection.

<Edge detection processing flow>
The edge detection flow for the substrate 200 in this embodiment will be described with reference to Figure 5. When the substrate 200 is loaded into the substrate loading chamber R1, the substrate 200 is positioned above the substrate carrier 100 so that the edge of the substrate 200 is roughly included in the field of view 351 of the imaging means 350. At this time, the substrate 200 is positioned at a reference position, but some deviation from the reference position is allowed. Then, as an imaging step, after the imaging means 350 captures an edge image of the substrate, the control unit C starts edge detection within the edge image (S100).

First, in the area setting process of step S101, a first detection area T1 and a second detection area T2 are set. At this time, a portion of the edge 210A (first side) of the substrate 200, which is located approximately in the reference position, is included in the first detection area T1, and a portion of the edge 210B (second side) is included in the second detection area T2.

In the line segment detection process of step S102, the control unit C detects line segments from the edge image. As described above, in this embodiment, the detection direction is set to a direction from the outside to the inside of the substrate 200. Therefore, if a scratch on the substrate carrier 100 is included in the edge image, the scratch on the substrate carrier 100 will be detected as a line segment before the edge of the substrate 200.

In the length acquisition process of step S103, the lengths of the line segments detected in step S102 are acquired. Then, in the score value calculation process of step S104, a score value for each line segment is acquired based on the line segment lengths acquired in step S103. In the first detection area T1, a first ratio of the length of the first line segment to the length Q1 of the first detection area T1 in the first direction D1 is calculated as the score value. Then, in the second detection area T2, a second ratio of the length of the second line segment to the length Q2 of the second detection area T2 in the second direction D2 is calculated as the score value.

In the determination process of step S105, it is determined whether the score value acquired in step S104 exceeds the threshold value. If it is determined that the score value does not exceed the threshold value (S
If the result of step S105 is NO, it is determined that the line segment detected in step S102 is not the edge of the substrate 200, and the process proceeds to the line segment detection step of step S106, where detection of a new line segment along the detection direction is started. Then, if a new line segment is detected in step S102, the processes from step S103 to step S105 are repeated again. Note that if a new line segment cannot be detected in step S106, an error may be notified to the user.

If it is determined in step S105 that the score value of the line segment exceeds the threshold value (YES in S105), the edge of the substrate 200 is detected in the edge detection process of step S107 based on the determination result of step S105. When the edge of the substrate 200 is detected in each detection area, edge detection ends (S108). Then, based on the position information of the substrate 200 obtained from the detected edge, the substrate 200 is aligned with the substrate carrier 100 as an alignment process.

As described above, according to this embodiment, even if the substrate carrier 100 has scratches or dirt, it is possible to reduce the chance of the scratches or dirt being mistakenly recognized as the edge of the substrate 200, and it is possible to detect the edge of the substrate 200 with high accuracy. This in turn makes it possible to prevent problems such as a decrease in alignment accuracy and damage to the substrate.

The configuration of the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention embodied in the above-mentioned embodiments. For example, in the above-mentioned embodiments, the present invention was applied to edge detection when aligning a substrate with a substrate carrier in a substrate loading chamber, but the present invention may also be applied when aligning a substrate in other chambers. Furthermore, in the above-mentioned embodiments, the score value used for substrate edge detection was the ratio of the line segment length to the length of the detection area, but the line segment length itself, or the difference between the line segment length and the length of the detection area, etc. may also be used as the score value.

In addition, in the edge detection flow shown in Figure 5, a determination is made by comparing the score value of a line segment with a threshold value, but the present invention is not necessarily limited to this. For example, a determination flow may be used in which the line segments detected within a detection area are compared and the line segment with the highest score value is detected as an edge. As a variation of the above-described embodiment, a method of comparing the line segments detected within a detection area and detecting the line segment with the highest score value as an edge will be described with reference to Figure 6.

When edge detection begins (S200), the maximum score value is set to 0 in step S201. Then, steps S202 through S205, which involve setting a detection area, detecting line segments within the detection area, and obtaining score values for the line segments, are the same as the edge detection flow shown in Figure 5.

In the determination processes of steps S206, 208, and 209, various determinations are made on the score value obtained in step S204. First, in step S206, it is determined whether the score value is 100 or greater. If it is determined that the score value is 100 or greater (YES in S206), the process proceeds to step S207, where line segments with a score value of 100 or greater are determined to be edges of the substrate 200, and edge detection ends (S214).

On the other hand, if it is determined in step S206 that the score value is less than 100 (NO in S206), the process proceeds to step S208, where it is determined whether the score value is equal to or greater than a threshold value. If the score value is equal to or greater than the threshold value (YES in S208), the process proceeds to step S209, where it is determined whether the score value is greater than the [maximum score value]. If the score value is greater than the [maximum score value] (YES in S209), the score value is substituted for the [maximum score value] in step S210. Then, in step S211, it is determined whether detection of all line segments within the detection area has been completed. Note that if it is determined in step S208 that the score value is less than the threshold value (NO in S208) or if it is determined in step S209 that the score value is less than the [maximum score value] (NO in S209), a new value is not substituted for the [maximum score value], and the process proceeds to step S211. Furthermore, the determination steps are not limited to being performed in the order described above, and the order of steps S208 and S209 may be reversed, or step S208 may be performed only for the highest score value after detection of all line segments has been completed.

If it is determined in step S211 that detection of all line segments has not been completed (NO in S211), the process proceeds to the line segment detection process in step S212, where detection of a new line segment along the detection direction is initiated. Then, when a new line segment is detected in step S203, the processes from step S204 to step S211 are repeated again.

If it is determined in step S211 that line segment detection is complete (YES in S211), then in the edge detection process of step S213, the line segment with the [maximum score value] from among the line segments detected so far is detected as the edge of the substrate 200. When the edge of the substrate 200 is detected in each detection area, edge detection ends (S214). Then, as an alignment process, the substrate 200 is aligned with the substrate carrier 100 based on the position information of the substrate 200 obtained from the detected edge. Note that if no line segments are detected within the detection area or if no line segments with a score value equal to or greater than the threshold value are detected, an error may be notified to the user. As described above, by increasing the criteria for determining that a line segment with a score value of 100 or greater or the longest line segment among the detected line segments is the edge of the substrate, it is possible to detect the edge of the substrate with greater accuracy.

<Film forming chamber>
The film formation process in the film formation chamber R3 will be described in more detail with reference to Figure 7. An evaporation source 600 is provided in the film formation chamber R3 as a film formation source. The substrate 200 held by the substrate carrier 100 is positioned and supported in the film formation chamber R3 so that the substrate 200 faces downward. A mask M is also provided below the substrate 200, positioned relative to the substrate 200. An opening is provided in the mask M at a position corresponding to the position where a thin film is to be formed on the substrate 200. Thus, a film is formed through the mask M on the substrate 200 held by the substrate carrier 100.

In this embodiment, film formation (deposition) is performed by vacuum evaporation. Specifically, film formation material evaporates or sublimes from evaporation source 600, and is deposited on substrate 200 to form a thin film on substrate 200. Since evaporation source 600 is a well-known technology, a detailed description thereof will be omitted. For example, evaporation source 600 can be composed of a container such as a crucible that contains film formation material, and a heating device that heats the container. Note that the film formation source is not limited to evaporation source 600, and may also be a sputtering cathode for forming a film by sputtering.

<Method of Manufacturing Electronic Device>
Next, an example of a method for manufacturing an electronic device using the film forming apparatus according to this embodiment will be described. The structure of an organic EL display device will be shown as an example of the electronic device, and a method for manufacturing the organic EL display device will be illustrated.

First, we will explain the organic EL display device to be manufactured. Figure 8(a) is an overall view of the organic EL display device 700, and Figure 8(b) shows the cross-sectional structure of one pixel.

As shown in FIG. 8(a), a plurality of pixels 702, each of which includes a plurality of light-emitting elements, are arranged in a matrix in the display region 701 of the organic EL display device 700. As will be explained in detail later, each light-emitting element has a structure including an organic layer sandwiched between a pair of electrodes. Note that the term "pixel" here refers to the smallest unit capable of displaying a desired color in the display region 701. In the organic EL display device of this embodiment, the pixel 702 is configured by a combination of a first light-emitting element 702R, a second light-emitting element 702G, and a third light-emitting element 702B, which emit light different from one another. The pixel 702 is often configured by a combination of red, green, and blue light-emitting elements, but may also be a combination of yellow, cyan, and white light-emitting elements, and is not particularly limited as long as it is of at least one color.

Figure 8(b) is a partial cross-sectional schematic diagram taken along line B-B in Figure 8(a). A pixel 702 consists of multiple light-emitting elements, each of which has a first electrode (anode) 704, a hole transport layer 705, one of light-emitting layers 706R, 706G, or 706B, an electron transport layer 707, and a second electrode (cathode) 708 on a substrate 703. Of these, the hole transport layer 705, light-emitting layers 706R, 706G, or 706B, and electron transport layer 707 are organic layers. In this embodiment, light-emitting layer 706R is an organic EL layer that emits red light, light-emitting layer 706G is an organic EL layer that emits green light, and light-emitting layer 706B is an organic EL layer that emits blue light. Light-emitting layers 706R, 706G, and 706B are formed in patterns corresponding to the light-emitting elements (sometimes referred to as organic EL elements) that emit red, green, and blue light, respectively.

The first electrode 704 is formed separately for each light-emitting element. The hole transport layer 705, electron transport layer 707, and second electrode 708 may be formed in common for multiple light-emitting elements 702R, 702G, and 702B, or may be formed for each light-emitting element. An insulating layer 709 is provided between the first electrodes 704 to prevent short-circuiting between the first electrode 704 and the second electrode 708 due to foreign matter. Furthermore, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 710 is provided to protect the organic EL element from moisture and oxygen.

In Figure 8(b), the hole transport layer 705 and the electron transport layer 707 are shown as a single layer, but depending on the structure of the organic EL display element, they may be formed of multiple layers including a hole blocking layer and an electron blocking layer. Furthermore, a hole injection layer having an energy band structure that can facilitate the injection of holes from the first electrode 704 to the hole transport layer 705 can also be formed between the first electrode 704 and the hole transport layer 705. Similarly, an electron injection layer can also be formed between the second electrode 708 and the electron transport layer 707.

Next, we will explain in detail an example of a manufacturing method for an organic EL display device.

First, a circuit (not shown) for driving the organic EL display device and a substrate (mother glass) 703 on which a first electrode 704 is formed are prepared.

An acrylic resin is formed by spin coating on the substrate 703 on which the first electrode 704 is formed, and the acrylic resin is then patterned using lithography to form an opening in the area where the first electrode 704 is formed, forming an insulating layer 709. This opening corresponds to the light-emitting area where the light-emitting element actually emits light.

The substrate 703 with the patterned insulating layer 709 is placed on a substrate carrier equipped with an adhesive material. The adhesive material holds the substrate 703 in place. The substrate is then transported into a first organic material deposition device and inverted, after which a hole transport layer 705 is deposited as a common layer on top of the first electrode 704 in the display area. The hole transport layer 705 is deposited by vacuum deposition. In practice, the hole transport layer 705 is formed to be larger than the display area 701, so a high-resolution mask is not required.

Next, the substrate 703, on which the hole transport layer 705 has been formed, is loaded into a second organic material film deposition apparatus. The substrate and mask are aligned, the substrate is placed on the mask, and a red-emitting light-emitting layer 706R is deposited on the portion of the substrate 703 where the red-emitting element will be located.

Similar to the formation of light-emitting layer 706R, light-emitting layer 706G that emits green light is formed using a third organic material film-forming apparatus, and then light-emitting layer 706B that emits blue light is formed using a fourth organic material film-forming apparatus. After the formation of light-emitting layers 706R, 706G, and 706B is complete, electron transport layer 707 is formed over the entire display area 701 using a fifth film-forming apparatus. Electron transport layer 707 is formed as a layer common to the three light-emitting layers 706R, 706G, and 706B.

The substrate on which the electron transport layer 707 has been formed is moved in a metallic evaporation material deposition device to deposit the second electrode 708.

Then, it is moved to a plasma CVD device where a protective layer 710 is deposited, completing the deposition process on the substrate 703. After inversion, the adhesive member is peeled off from the substrate 703, separating the substrate 703 from the substrate carrier. After that, it is cut to complete the organic EL display device 700.

If the substrate 703 with the patterned insulating layer 709 is exposed to an atmosphere containing moisture or oxygen from the time it is loaded into the film-forming apparatus until the formation of the protective layer 710 is completed, the light-emitting layer made of organic EL material may be deteriorated by the moisture or oxygen. Therefore, in this embodiment, the substrate is loaded and unloaded between the film-forming apparatuses in a vacuum atmosphere or an inert gas atmosphere.

100...Carrier (holding means), 200...Substrate, 220A...Intersection (first reference point), 220B...Intersection (second reference point), 350...Image capture means (photographing means), 411...Support pin (support means), C...Control unit (determination means), L1...Distance

Claims (15)

An alignment apparatus for aligning a substrate with respect to a holding means for holding the substrate, comprising:
an imaging means for capturing an edge image including the edge of the substrate held by the holding means;
an edge detection means for setting a detection area within the edge image and detecting an edge of the substrate from within the detection area along a reference direction of the detection area;
an alignment means for aligning the substrate with respect to the holding means based on the edge detected by the edge detection means;
Equipped with
An alignment device characterized in that the edge detection means determines whether the line segment is an edge of the substrate based on the length of the detection area in the reference direction and the length of the line segment along the reference direction detected within the detection area. The substrate has a substantially rectangular surface,
2. The alignment apparatus according to claim 1, wherein the reference direction is a direction parallel to a side of the substrate when the substrate is in a predetermined reference position. An alignment device as described in claim 1, characterized in that the detection area is rectangular with sides parallel to the reference direction. The alignment device described in claim 1, characterized in that the edge detection means calculates the ratio of the length of the line segment to the length of the detection area in the reference direction, and determines that the line segment is the edge of the substrate if the ratio is equal to or greater than a predetermined value. The alignment device described in claim 1, characterized in that the edge detection means determines that the line segment is the edge of the substrate if the length of the line segment is equal to or greater than the length of the detection area in the reference direction. The alignment device of claim 1, wherein the edge detection means determines that the longest line segment detected within the detection area is the edge of the substrate. the imaging means captures an image of the substrate when the substrate is at a predetermined reference position so that the edge image includes a first side of the substrate extending in a first direction and a second side of the substrate extending in a second direction different from the first direction;
2. The alignment apparatus according to claim 1, wherein the edge detection means sets, as the detection area, a first detection area including the first side and a second detection area including the second side. the first detection area has a rectangular shape that is long in the second direction,
8. The alignment apparatus according to claim 7, wherein the second detection area has a rectangular shape that is long in the first direction. the edge image has a rectangular shape that is long in the first direction,
8. The alignment apparatus according to claim 7, wherein the length of the first detection area in the first direction is longer than the length of the second detection area in the second direction. The edge detection means
calculating a first ratio of a length of a first line segment within the first detection area to a length of the first detection area in the first direction, and determining that the first line segment is an edge of the substrate when the first ratio is equal to or greater than a first threshold value;
8. The alignment device according to claim 7, further comprising: calculating a second ratio of the length of a second line segment within the second detection area to the length of the second detection area in the second direction; and determining that the second line segment is an edge of the substrate if the second ratio is equal to or greater than a second threshold value. An alignment device as described in claim 1, characterized in that the edge detection means detects the line segment from the detection area based on the contrast of the edge image. The alignment device described in claim 1, characterized in that the edge detection means determines whether the line segment is an edge based on the angle of the line segment in addition to the length of the line segment. The alignment device described in claim 1, characterized in that the edge detection means determines whether the line segment is an edge based on the thickness of the line segment in addition to the length of the line segment. An alignment device according to any one of claims 1 to 13;
a film forming source that emits a film forming material toward the substrate held by the holding means;
A film forming apparatus comprising: an imaging step of capturing an edge image including an edge of the substrate held by a holding means for holding the substrate;
a region setting step of setting a detection region within the edge image;
a line segment detection step of detecting a line segment along a reference direction of the detection area within the detection area;
a length acquisition step of acquiring the length of the line segment;
an edge detection step of detecting an edge of the substrate from the edge image based on the length of the line segment and the length of the detection area in the reference direction;
an alignment step of aligning the substrate with respect to the holding means based on the edge of the substrate detected in the edge detection step;
An alignment method comprising: