Alignment device, alignment method, film forming device, and manufacturing method

Abstract

To provide a technique having an advantage of detecting a mark provided to each of a substrate and a mask.SOLUTION: An alignment device is used for an alignment between a substrate and a mask for forming a pattern onto a film formation surface of the substrate. In a state where the substrate and the mask are overlapped, the alignment device is arranged to a side opposite to the mask, and has a camera for detecting a first mark provided to a back surface on a side opposite to the film formation surface of the substrate and a second mark provided on the mask. The mask includes: a pattern part including an opening for forming the pattern; and a projection part projected from an outer edge part of an opposite surface that is faced to the film formation surface of the pattern part on a side where the substrate is overlapped. The camera detects the second mark provided on an upper surface of the projection part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an alignment apparatus, an alignment method, a film forming apparatus, and a manufacturing method. [Background technology]

[0002] Organic EL display devices (organic EL displays) are being used in smartphones, televisions, automotive displays, and also in VR HMDs (Virtual Reality Head Mount Displays), etc. In the process of manufacturing organic EL display devices, a film formation device is generally used when forming organic light emitting elements (organic EL elements: OLED) on a substrate.

[0003] The film forming device deposits the deposition material (film forming material) emitted from the deposition source onto the substrate through a mask on which a pattern corresponding to the pixel pattern is formed, forming a film such as an organic film or a metal film. During this process, it is necessary to align the substrate and the mask with high precision.

[0004] Techniques relating to the alignment of a substrate and a mask have been proposed in the past (see Patent Document 1). Patent Document 1 discloses a technique for measuring the relative positions (positional deviation) of marks provided on the substrate and the mask, respectively, with a camera provided on the opposite side of the mask with the substrate as a reference, and adjusting the position of at least one of the substrate and the mask based on the measurement results. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 222009 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] A camera used for aligning a substrate and a mask generally optically measures the position of a mark provided on a substrate or a mask by illuminating the mark with measurement light such as visible light and detecting (observing) the measurement light (reflected light) reflected by the mark. Therefore, if the transmittance of the substrate or mask is low with respect to the measurement light used by the camera, the amount of measurement light (reflected light from the mark) detected by the camera decreases, and the measurement accuracy of the position of the mark provided on the substrate or mask decreases. In addition, depending on the transmittance of the substrate or mask with respect to the measurement light, it may be difficult to measure the position of the mark provided on the substrate or mask.

[0007] The present invention has been made in view of the problems with the conventional technology, and has an exemplary object to provide a technique that is advantageous for detecting marks provided on a substrate and a mask, respectively. [Means for solving the problem]

[0008] An alignment device as one aspect of the present invention is an alignment device used for aligning a substrate and a mask for depositing a pattern on a deposition surface of the substrate, and has a camera that is positioned on the opposite side of the mask when the substrate and the mask are superimposed, and detects a first mark provided on the back surface of the substrate opposite the deposition surface and a second mark provided on the mask, the mask including a pattern portion including an opening for depositing the pattern, and a protrusion portion protruding from the outer edge of an opposing surface facing the deposition surface of the pattern portion on the side on which the substrate is superimposed, and the camera detects the second mark provided on the upper surface of the protrusion portion.

[0009] Further objects or other aspects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Effect of the Invention

[0010] According to the present invention, for example, it is possible to provide a technique that is advantageous for detecting marks provided on a substrate and a mask, respectively. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a schematic configuration of a production line to which a film forming apparatus according to one aspect of the present invention can be applied; [Diagram 2] 1 is a diagram illustrating a schematic configuration of a film forming apparatus according to one aspect of the present invention. [Diagram 3] 2 is an enlarged view showing the substrate, the mask, the substrate holding portion, and the mask holding portion and their vicinity; FIG. [Figure 4] 2 is an enlarged view showing the substrate, the mask, the substrate holding portion, and the mask holding portion and their vicinity; FIG. [Diagram 5] FIG. 1 is a diagram illustrating a schematic configuration of a camera. [Figure 6] FIG. 1 is a diagram for explaining an organic EL display device as an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. In addition, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0013] 1 is a diagram showing a schematic configuration (layout) of a manufacturing line 100 to which a film forming apparatus according to one aspect of the present invention can be applied. The manufacturing line 100 includes a system that performs a film forming process on a substrate that is carried in and carries out the substrate after the film forming process, and is configured as, for example, a manufacturing line for electronic devices. In each of the following figures, arrow Z indicates the up-down direction (vertical (gravity) direction), and arrows X and Y indicate horizontal directions that are perpendicular to each other.

[0014] The manufacturing line 100 (film forming apparatus) is particularly suitable as a line for manufacturing organic light-emitting elements such as OLEDs and organic photoelectric conversion elements such as organic thin-film solar cells. Examples of electronic devices include light-emitting elements, photoelectric conversion elements, and touch panels. In this embodiment, the electronic devices include display devices (e.g., organic EL display devices) and lighting devices (e.g., organic EL lighting devices) equipped with light-emitting elements, and sensors (e.g., organic CMOS image sensors) equipped with photoelectric conversion elements.

[0015] In this embodiment, the manufacturing line 100 is embodied as a line for manufacturing a display panel of an organic EL display device for a smartphone or a display panel of an organic EL display device for a VR HMD. When manufacturing a display panel for a smartphone, a 4.5 generation substrate (about 700 mm x about 900 mm), a 6th generation full size substrate (about 1500 mm x about 1850 mm), or a half cut size substrate (about 1500 mm x about 925 mm) is used. Films are formed on such substrates to form organic EL elements, and the substrates are cut out to manufacture a plurality of small size panels. When manufacturing a display panel for a VR HMD, a silicon wafer of a predetermined size (for example, 300 mm) is used. Films are formed on such silicon wafers to form organic EL elements, and the silicon wafer is cut out along the regions (scribe regions) between the element formation regions to manufacture a plurality of small size panels. However, the size and type of the substrate are not particularly limited and can be set appropriately.

[0016] 1, the manufacturing line 100 has a transfer chamber 120 having an octagonal shape in a plan view. A substrate 101 to be subjected to a film forming process is carried into the transfer chamber 120 via a transfer path 110 (carry-in path). The substrate 101 to which the film forming process has been performed is carried out from the transfer chamber 120 to a transfer path 111 (carry-out path).

[0017] A plurality of film forming apparatuses 1 that perform film forming processing on a substrate 101 are arranged around the transfer chamber 120. A transfer chamber 130 having an octagonal shape in a plan view is arranged adjacent to each of the film forming apparatuses 1. A storage chamber 140 that stores a mask 102 is arranged around the transfer chamber 130.

[0018] The transfer chamber 120 is provided with a transfer unit 121 that transfers the substrate 101. In this embodiment, the transfer unit 121 includes a horizontal articulated robot, and transfers the substrate 101 while holding it in a horizontal position. The transfer unit 121 performs a carry-in operation of carrying the substrate 101, on which a film formation process is to be performed, from the transfer path 110 to the film formation apparatus 1, and a carry-out operation of carrying the substrate 101, on which a film formation process is to be performed, out of the film formation apparatus 1 to the transfer path 111.

[0019] Each of the transfer chambers 130 is provided with a transfer unit 131 that transfers the mask 102. In this embodiment, the transfer unit 131 includes a horizontal articulated robot, and transfers the mask 102 while holding it in a horizontal position. The transfer unit 131 performs an operation of transferring the mask 102 from the storage chamber 140 to the film forming apparatus 1, and an operation of transferring the mask 102 from the film forming apparatus 1 to the storage chamber 140.

[0020] FIG. 2 is a diagram showing a schematic configuration of a film forming apparatus 1 according to one aspect of the present invention. The film forming apparatus 1 performs a film forming process in which a deposition material is attached (deposited) to a substrate 101 to form a film, and in this embodiment, a film is formed on the substrate 101 through a mask 102. Specifically, the film forming apparatus 1 forms a thin film of a deposition material in a predetermined pattern on a film forming surface 101A of the substrate 101 through the mask 102. The material of the substrate 101 can be appropriately selected from glass, resin, metal, and the like. In particular, in this embodiment, the substrate 101 includes, for example, a glass substrate on which a TFT (Thin Film Transistor) is formed and a silicon wafer on which a semiconductor element is formed. The mask 102 is made of a magnetic material such as a metal. As the deposition material, an organic material or an inorganic material (for example, a metal, a metal oxide), etc. are used. Here, an example in which the film forming apparatus 1 performs a film forming process on the substrate 101 by vacuum deposition will be described, but the present invention is not limited thereto, and various film forming processes (film forming methods) such as sputtering and CVD can be applied.

[0021] The film forming apparatus 1 has a box-shaped vacuum chamber 2. The internal space of the vacuum chamber 2 is maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen gas. In this embodiment, the vacuum chamber 2 is connected to a vacuum pump (not shown) in order to maintain the internal space in a vacuum atmosphere.

[0022] A deposition unit 10 is provided in the internal space of the vacuum chamber 2. The deposition unit 10 includes a deposition source that releases a deposition material upward. A shutter 10a is provided above the deposition unit 10 to restrict the release of the deposition material from the deposition source and to release such restriction. The shutter 10a is opened and closed by an opening / closing mechanism (not shown). FIG. 2 shows a state in which the shutter 10a is closed and the release of the deposition material from the deposition unit 10 is restricted. An adhesion prevention plate 2a is further provided above the deposition unit 10. The adhesion prevention plate 2a is provided at the top of the internal space of the vacuum chamber 2 and has a function of suppressing (preventing) the deposition material released from the deposition unit 10 from unnecessarily adhering to the structure.

[0023] In the internal space of the vacuum chamber 2, a substrate holding unit 3 is provided that holds the substrate 101 in a horizontal position. The substrate holding unit 3 is disposed on the opposite side of the mask 102 in the internal space of the vacuum chamber 2. In this embodiment, the substrate holding unit 3 is configured as an electrostatic chuck (first electrostatic chuck) that attracts and holds the substrate S by electrostatic force. Specifically, the substrate holding unit 3 attracts the back surface 101B of the substrate 101 opposite to the film formation surface 101A, thereby holding the substrate 101 with the film formation surface 101A of the substrate 101 facing downward (-Z direction). The substrate holding unit 3 may be provided with, for example, a cooling plate (not shown) including a water cooling mechanism. The cooling plate cools the substrate 101 via the substrate holding unit 3 during the film formation process.

[0024] The substrate holder 3 (and the cooling plate) is supported (suspended) by a magnetic plate 5 via a support (not shown). The magnetic plate 5 is a plate that applies a magnetic force to the mask 102 to attract the mask 102. In the film formation process, the substrate 101 is sandwiched between the magnetic plate 5 and the mask 102 attracted by the magnetic plate 5. The magnetic plate 5 is provided to bring the substrate 101 and the mask 102 close to each other or to bring the substrate 101 and the mask 102 into close contact with each other (to improve adhesion).

[0025] The film forming apparatus 1 has a mask holding mechanism 6 for holding the mask 102. The mask holding mechanism 6 includes a mask holding part 6a for holding the mask 102 in a horizontal position, and an actuator 6b. The mask holding part 6a is disposed in the internal space of the vacuum chamber 2 on the side of the back surface 101B of the substrate 101 held by the substrate holding part 3 so as to surround the substrate holding part 3. In this embodiment, the mask holding part 6a is configured as an electrostatic chuck (second electrostatic chuck) that attracts and holds the mask 102 by electrostatic force. The specific configuration of the mask holding part 6a will be described in detail later. The actuator 6b includes, for example, an electric cylinder or an electric ball screw mechanism, and raises and lowers the mask holding part 6a.

[0026] The film forming apparatus 1 has an alignment device 8 used for aligning the substrate 101 and the mask 102. The alignment device 8 has a driving mechanism 80 and a plurality of cameras CR. The driving mechanism 80 includes a distance adjustment unit 81, a support shaft 82, a stand 83, and a position adjustment unit 84.

[0027] The distance adjustment unit 81 is a mechanism that includes, for example, an electric cylinder or an electric ball screw mechanism, and raises and lowers the support shaft 82 in the Z direction. A magnet plate 5 is supported (fixed) on the lower end of the support shaft 82. Therefore, the distance adjustment unit 81 raises and lowers the support shaft 82, and the substrate holding part 3 is raised and lowered via the magnet plate 5. By raising and lowering the substrate holding part 3, the distance between the substrate 101 and the mask 102 in the vertical direction (Z direction) is adjusted, and the substrate 101 and the mask 102 held by the substrate holding part 3 are brought closer to or separated from each other (separated). In other words, the distance adjustment unit 81 brings the substrate 101 and the mask 102 closer to or apart from each other in the overlapping direction (Z direction). The "distance" adjusted by the distance adjustment unit 81 is the so-called vertical distance. Therefore, the distance adjustment unit 81 can also be said to be a unit that adjusts the vertical position of the substrate 101 held by the substrate holding part 3. The distance adjustment unit 81 is mounted on a position adjustment unit 84 via a stand 83 .

[0028] The position adjustment unit 84 adjusts the relative position of the substrate 101 with respect to the mask 102 in the XY plane by displacing (moving) the substrate holding part 3 in the horizontal direction. In this way, the position adjustment unit 84 functions as a unit that adjusts the relative horizontal position of the substrate 101 and the mask 102. In this embodiment, the position adjustment unit 84 displaces the substrate holding part 3 in a rotation direction (θ direction) around the axis in the X direction, Y direction, and Z direction. Note that in this embodiment, the position of the mask 102 is fixed and the substrate 101 is displaced to adjust the relative position of the substrate 101 and the mask 102, but this is not limited to this. For example, the relative position of the substrate 101 and the mask 102 may be adjusted by fixing the position of the substrate 101 and displacing the mask 102, or by displacing both the substrate 101 and the mask 102.

[0029] The position adjustment unit 84 includes a fixed plate 84a and a movable plate 84b. The fixed plate 84a and the movable plate 84b are rectangular frame-shaped plates. The fixed plate 84a is fixed to the upper wall portion 20 of the vacuum chamber 2. An actuator is provided between the fixed plate 84a and the movable plate 84b for displacing the movable plate 84b in rotational directions around axes in the X-, Y-, and Z-directions relative to the fixed plate 84a.

[0030] A frame-shaped stand 83 is placed on the movable plate 84b, and a distance adjustment unit 81 is supported on the stand 83. Therefore, when the movable plate 84b is displaced, the stand 83 and the distance adjustment unit 81 are displaced integrally, so that the substrate 101 held by the substrate holder 3 can be displaced in the rotational directions around the axes in the X, Y, and Z directions. An opening is formed in the upper wall 20 for providing the support shaft 82 and the like. The opening is sealed by a sealing member (not shown) such as a bellows, and the internal space of the vacuum chamber 2 is kept airtight.

[0031] The camera CR is embodied as an imaging device that captures an image of a measurement target and functions as, for example, a measuring instrument that measures the position of the measurement target. The camera CR is provided, for example, on the upper wall 20 of the vacuum chamber 2. In this embodiment, the camera CR detects marks (alignment marks) provided on each of the substrate 101 and the mask 102 arranged in the internal space of the vacuum chamber 2, and measures the relative position (misalignment) between the substrate 101 and the mask 102 from these positions. In aligning the substrate 101 and the mask 102, the relative positions of the substrate 101 and the mask 102 are adjusted via the position adjustment unit 84 so that the misalignment between the substrate 101 and the mask 102 measured by the camera CR falls within an allowable range.

[0032] The film forming apparatus 1 is composed of a computer (information processing device) and has a control unit 9 that controls each component (operation) of the film forming apparatus 1 in an integrated manner to control the entire film forming apparatus 1. The control unit 9 includes a processing unit 90, a storage unit 91, an input / output (I / O) interface 92, and a communication unit 93. The processing unit 90 includes a processor represented by a CPU, and realizes various operations and processes of the film forming apparatus 1 by executing a program stored in the storage unit 91. The storage unit 91 includes storage devices such as a ROM, a RAM, and a HDD, and stores programs executed by the processing unit 90 and various control information. The I / O interface 92 is an interface for communication (transmission and reception of various information and signals) between the processing unit 90 and an external device. The communication unit 93 is a communication device that communicates with a higher-level device, other control devices, etc. via a communication line.

[0033] Hereinafter, an example of control of the film forming apparatus 1 executed by the control unit 9 (processing unit 90) will be described, from loading the substrate 101 through the film forming process to unloading the substrate 101.

[0034] First, the substrate 101 is carried into (the internal space of) the vacuum chamber 2. The substrate 101 is carried below the substrate holding part 3 by the transport unit 121. The lower surface of the substrate holding part 3, i.e., the adsorption surface 3a (holding surface that holds the substrate 101) that adsorbs the back surface 101B of the substrate 101, is configured horizontally (flat). Then, the substrate 101 carried below the substrate holding part 3 is transferred to the substrate holding part 3. For example, the substrate 101 is pressed against the adsorption surface 3a of the substrate holding part 3 by raising the transport unit 121 (driving it in the +Z direction). In this state, the function of the substrate holding part 3 as an electrostatic chuck is activated, the adsorption surface 3a adsorbs the back surface 101B of the substrate 101, and the substrate 101 is held by the substrate holding part 3.

[0035] Next, the mask 102 is carried into (the internal space of) the vacuum chamber 2. The mask 102 is carried by the transport unit 131 from the storage chamber 140 to the vacuum chamber 2, and is carried to below the mask holding unit 6a and below the substrate 101 held by the substrate holding unit 3. The lower surface of the mask holding unit 6a, that is, the adsorption surface 61a (holding surface that holds the mask 102) that adsorbs the facing surface 102A of the mask 102, is configured horizontally (flat). Here, the facing surface 102A of the mask 102 is a surface that faces the film formation surface 101A of the substrate 101 held by the substrate holding unit 3, and is a surface on the opposite side to the surface of the deposition unit 10 (deposition source). Then, the mask 102 located below the mask holding unit 6a and the substrate 101 is transferred to the mask holding unit 6a. For example, the transport unit 131 is raised (driven in the +Z direction) to press the mask 102 against the adsorption surface 61a of the mask holding unit 6a. In this state, the function of the mask holding portion 6a as an electrostatic chuck is activated, and the opposing surface 102A of the mask 102 is attracted to the attracting surface 61a, and the mask holding portion 6a holds the mask 102. In addition, the actuator 6b further raises the mask holding portion 6a holding the mask 102 (drives it in the +Z direction), and the mask 102 is positioned at an alignment position for aligning the substrate 101 and the mask 102.

[0036] Next, the substrate 101 held by the substrate holder 3 and the mask 102 held by the mask holder 6a are aligned. The alignment between the substrate 101 and the mask 102 is performed in a state where the substrate 101 and the mask 102 are overlapped. However, the state where the substrate 101 and the mask 102 are overlapped means a state where the substrate 101 and the mask 102 are overlapped from the viewpoint of the Z direction, and includes both a state where the substrate 101 and the mask 102 are in physical contact and a state where they are not in contact. Therefore, in the alignment between the substrate 101 and the mask 102, a gap may be provided between the substrate 101 and the mask 102. In this way, in a state where the substrate 101 and the mask 102 are overlapped, the mark provided on the substrate 101 and the mark provided on the mask 102 are detected by the camera CR provided on the upper wall portion 20 of the vacuum chamber 2.

[0037] The camera CR illuminates the marks provided on the substrate 101 and the mask 102 with visible light (measurement light) and detects (observes) the light reflected by the marks, thereby optically measuring the positions of the marks provided on the substrate 101 and the mask 102. Therefore, if the transmittance of the substrate 101 or the mask 102 is low for the visible light (measurement light) used by the camera CR, the amount of light detected by the camera CR is small, resulting in a decrease in measurement accuracy or making the measurement itself difficult.

[0038] Therefore, in this embodiment, the substrate 101, the mask 102, the substrate holder 3, and the mask holder 6a are provided with a configuration (structure) that is advantageous for detecting the marks provided on the substrate 101 and the mask 102 with the camera CR. Hereinafter, the configuration that is advantageous for detecting the marks provided on the substrate 101 and the mask 102 with the camera CR will be specifically described with reference to Figs. 3 and 4. Figs. 3 and 4 are enlarged views showing the substrate 101, the mask 102, the substrate holder 3, and the mask holder 6a and their vicinity. Fig. 3 shows a cross-sectional view of the substrate 101, the mask 102, the substrate holder 3, and the mask holder 6a, and Fig. 4 shows a top view of the substrate 101, the mask 102, the substrate holder 3, and the mask holder 6a.

[0039] 3 and 4, the substrate 101 is provided on its rear surface 101B with a first mark M1 to be measured by the camera CR. The first mark M1 is realized as an alignment mark detected by the camera CR during alignment between the substrate 101 and the mask 102. Therefore, the first mark M1 is provided on the rear surface 101B of the substrate 101 so as to fall within the range of the field of view (detection range) of the camera CR provided on the upper wall portion 20 of the vacuum chamber 2. This makes it possible to detect the first mark M1 provided on the rear surface 101B of the substrate 101 with the camera CR during alignment between the substrate 101 and the mask 102.

[0040] On the other hand, the mask 102 includes a pattern portion 102C including an opening (not shown) for forming a pattern on the deposition surface 101A of the substrate 101, and a protruding portion 102D provided around the pattern portion 102C. As shown in FIG. 3, the protruding portion 102D is a portion that protrudes from an outer edge portion OE of the opposing surface 102A of the pattern portion 102C along the side surface 101C of the substrate 101 on the side where the substrate 101 is overlapped (in the +Z direction). In addition, a second mark M2 that is a measurement target of the camera CR is provided on the upper surface 102E of the protruding portion 102D. The second mark M2 is realized as an alignment mark detected by the camera CR during alignment between the substrate 101 and the mask 102. Therefore, the second mark M2 is provided on the upper surface 102E of the protruding portion 102D so as to be within the range of the field of view (detection range) of the camera CR provided on the upper wall portion 20 of the vacuum chamber 2 and close to the first mark M1 provided on the rear surface 101B of the substrate 101. This makes it possible to detect the second mark M2 provided on the upper surface 102E of the protruding portion 102D of the mask 102 by the camera CR during alignment between the substrate 101 and the mask 102.

[0041] When aligning the substrate 101 and the mask 102, the camera CR detects the first mark M1 provided on the substrate 101 and the second mark M2 provided on the mask 102. In this embodiment, as described above, the first mark M1 is provided on the back surface 101B of the substrate 101, and the second mark M2 is provided on the upper surface 102E of the protruding portion 102D of the mask 102. Therefore, even if the transmittance of the substrate 101 and the mask 102 to the visible light (measurement light) used by the camera CR is low, the camera CR can detect the light (reflected light) from each of the first mark M1 and the second mark M2 with a sufficient amount of light. This is because the camera CR can detect the light from the first mark M1 and the second mark M2 without transmitting the light through the substrate 101 and the mask 102. In this way, by detecting the first mark M1 provided on the back surface 101B of the substrate 101 and the second mark M2 provided on the upper surface 102E of the protrusion 102D of the mask 102, it is possible to measure the relative position (positional misalignment) between the substrate 101 and the mask 102 with high accuracy.

[0042] From the viewpoint of detecting the first mark M1 and the second mark M2 with high accuracy and / or from the viewpoint of simplifying the configuration of the camera CR, it is necessary to fit the first mark M1 and the second mark M2 within the range of the depth of field (depth of focus) of the camera CR. Therefore, the first mark M1 and the second mark M2 are provided on the back surface 101B of the substrate 101 and the upper surface 102E of the protruding portion 102D of the mask 102, respectively, so that they fit within the range of the depth of field of the camera CR when the substrate 101 and the mask 102 are superimposed. In other words, the protruding amount (height in the Z direction) of the protruding portion 102D of the mask 102 is set based on the first mark M1 so that the second mark M2 fits within the range of the depth of field of the camera CR. 3, the protrusion amount of the protrusion 102D is set so that the position in the height direction (Z direction) of the back surface 101B of the substrate 101 held by the substrate holder 3 coincides with the position in the height direction of the top surface 102E of the protrusion 102D. However, since the depth of field of the camera CR generally has a certain margin, it is not necessary to strictly coincide the position in the height direction of the back surface 101B of the substrate 101 with the position in the height direction of the top surface 102E of the protrusion 102D. For example, the protrusion amount (P) of the protrusion 102D is set to be ±5% of the sum of the thickness (T) of the substrate 101 and the gap (G) between the substrate 101 and the mask 102 (P=(T+G)×±0.05).

[0043] In addition, in a configuration in which the light (reflected light) from each of the first mark M1 and the second mark M2 is detected by the camera CR provided on the upper wall portion 20 of the vacuum chamber 2, the substrate holding portion 3 and the mask holding portion 6a are also one of the factors that reduce the amount of light detected by the camera CR. In particular, when the transmittance of the substrate holding portion 3 and the mask holding portion 6a for the visible light (measurement light) used by the camera CR is low, the reduction in the amount of light detected by the camera CR becomes significant. Therefore, it is preferable that the substrate holding portion 3 is configured so that the first mark M1 provided on the back surface 101B of the substrate 101 is exposed when the substrate holding portion 3 is holding the substrate 101. Similarly, it is preferable that the mask holding portion 6a is configured so that the second mark M2 provided on the upper surface 102E of the protruding portion 102D of the mask 102 is exposed when the mask holding portion 6a is holding the mask 102. For example, as shown in FIG. 4, the substrate holding portion 3 is provided with a structure 32 for exposing the first mark M1 at a portion corresponding to the first mark M1 when the substrate 101 is held. Furthermore, the mask holding part 6a is provided with a structure 62 for exposing the second mark M2 at a portion corresponding to the second mark M2 in a state in which the mask 102 is held. Specific examples of the structure 32 for exposing the first mark M1 and the structure 62 for exposing the second mark M2 include a through hole or a notch. By configuring each of the substrate holding part 3 and the mask holding part 6a so that the first mark M1 and the second mark M2 are exposed, it is possible to suppress a decrease in the amount of light from the first mark M1 and the second mark M2 detected by the camera CR.

[0044] In this way, the camera CR detects the first mark M1 on the substrate 101 and the second mark M2 on the mask 102, and the relative position (misalignment) between the substrate 101 and the mask 102 is measured from their positions. If the misalignment between the substrate 101 and the mask 102 measured by the camera CR (the result of detecting the first mark M1 and the second mark M2) is within the allowable range, the alignment between the substrate 101 and the mask 102 is terminated. On the other hand, if the misalignment between the substrate 101 and the mask 102 measured by the camera CR is not within the allowable range, the alignment between the substrate 101 and the mask 102 is performed so that the misalignment is reduced to be within the allowable range. Specifically, first, based on the misalignment between the substrate 101 and the mask 102 measured by the camera CR, the displacement amount of the substrate 101, which is the control amount required to keep the misalignment within the allowable range, is calculated. The misalignment between the substrate 101 and the mask 102 is defined by the distance and direction (X, Y, θ) of the misalignment. Then, based on the displacement amount of the substrate 101 obtained as the control amount, the position adjustment unit 84 displaces the substrate holding part 3 in the XY plane to adjust the relative position of the substrate 101 with respect to the mask 102. Measurement of the relative position between the substrate 101 and the mask 102 by the camera CR and adjustment of the position of the substrate 101 by the position adjustment unit 84 (alignment of the substrate 101 and the mask 102) are repeated until the misalignment between the substrate 101 and the mask 102 falls within an allowable range. Whether the misalignment between the substrate 101 and the mask 102 falls within an allowable range can be determined, for example, by obtaining the distance between the first mark M1 and the second mark M2 and comparing the distance (average value or sum of squares) with a threshold value.

[0045] Next, a film formation process is performed to form a film on the film formation surface 101A of the substrate 101. After the substrate 101 and the mask 102 are aligned, the substrate 101 and the mask 102 are overlapped. For example, the substrate holder 3 is lowered (driven in the -Z direction) to bring the entire film formation surface 101A of the substrate 101 into contact with the mask 102 (the opposing surface 102A of the mask), and the magnet plate 5, the substrate holder 3, the substrate 101, and the mask 102 are brought into close contact from above. As described above, the mask 102 is attracted to the magnet plate 5 by the magnetic force acting between the magnet plate 5 and the mask 102, so that the substrate 101 and the mask 102 can be brought into close contact with each other as a whole. Then, the shutter 10a is opened to release the deposition material from the deposition unit 10, and the deposition material adheres to the film formation surface 101A of the substrate 101 through the mask 102, forming a film of the deposition material in a predetermined pattern.

[0046] Next, the mask 102 is carried out from (the internal space of) the vacuum chamber 2. First, the substrate holding part 3 is raised (driven in the +Z direction) to separate the substrate 101 and the mask 102. In addition, the transport unit 131 is positioned below the mask 102, and the mask holding part 6a is lowered (driven in the -Z direction) to transfer the mask 102 from the mask holding part 6a to the transport unit 131. Then, the mask 102 is transported to the storage room 140 by the transport unit 131.

[0047] Next, the substrate 101 that has undergone the film formation process is carried out from (the internal space of) the vacuum chamber 2. The transfer unit 121 is positioned below the substrate 101, and the substrate holding part 3 is lowered (driven in the -Z direction) to transfer the substrate 101 from the substrate holding part 3 to the transfer unit 121. Then, the transfer unit 121 transfers the substrate 101 to the transfer path 111.

[0048] In this manner, the process of carrying in the substrate 101, performing the film formation process, and carrying out the substrate 101 is completed. As described above, in this embodiment, since it is possible to measure the relative position (positional deviation) between the substrate 101 and the mask 102 with high accuracy, it is possible to improve the alignment accuracy between the substrate 101 and the mask 102. As a result, in the film formation process, a film of a deposition material having a predetermined pattern can be formed at a predetermined position on the film formation surface 101A of the substrate 101.

[0049] In addition, the configuration (detection method) of the camera CR that detects the first mark M1 provided on the back surface 101B of the substrate 101 and the second mark M2 provided on the upper surface 102E of the protrusion 102D of the mask 102 is a transmitted illumination method or a coaxial incident illumination method.

[0050] Fig. 5(A) is a diagram showing a schematic configuration of a camera CR employing a transmitted illumination method. In the transmitted illumination method, as shown in Fig. 5(A), a light source LS that emits visible light is disposed below a mark M (alignment mark) to be measured, and a sensor SS such as an image sensor is disposed above the mark M. Then, the visible light from the light source LS is used to illuminate the mark M from below, and the visible light transmitted through the mark M is detected by the sensor SS to detect the mark M (position). In this way, in the transmitted illumination method, the light source LS needs to be disposed below the mark M to be measured, so that when the transmitted illumination method is applied to the film forming apparatus 1, the light source LS is disposed between the substrate 101 and the deposition unit 10.

[0051] FIG. 5B is a diagram showing a schematic configuration of a camera CR employing a coaxial epi-illumination method. In the coaxial epi-illumination method, as shown in FIG. 5B, a light source LS and a sensor SS are arranged above a mark M (alignment mark) to be measured, and a half mirror HM is arranged between the light source LS and the sensor SS, more specifically, between the light source LS and the mark M. Then, visible light from the light source LS is reflected by the half mirror HM to illuminate the mark M from above, and the visible light reflected by the mark M is transmitted through the half mirror HM and detected by the sensor SS to detect the mark M (position). In this way, in the coaxial epi-illumination method, the light source LS can be arranged above the mark M to be measured, so that it can be easily applied to the film forming apparatus 1 compared to the transmitted illumination method. In addition, the configuration of the camera CR employing the coaxial epi-illumination method is simple and can be realized at low cost.

[0052] Next, a method for manufacturing an electronic device using the film forming apparatus 1 (the manufacturing line 100 having the film forming apparatus 1) in this embodiment will be described. Here, an organic EL display device will be taken as an example of the electronic device.

[0053] First, an organic EL display device will be described. Fig. 6(A) is a diagram showing an overall configuration of an organic EL display device 50. Fig. 6(B) is a diagram showing a cross-sectional structure of one pixel of the organic EL display device 50.

[0054] As shown in FIG. 6A, the organic EL display device 50 has a display area 51 in which pixels 52 including a plurality of light-emitting elements are arranged in a matrix. As described later, each of the plurality of light-emitting elements has a structure including an organic layer (organic film) sandwiched between a pair of electrodes. In this embodiment, a pixel means a minimum unit that allows a predetermined color to be displayed in the display area 51. For example, in the organic EL display device 50, a pixel 52 is configured by a combination of a first light-emitting element 52R, a second light-emitting element 52G, and a third light-emitting element 52B that allow different colors to be displayed. The pixel 52 is generally configured by a combination of a red light-emitting element, a green light-emitting element, and a blue light-emitting element, but is not limited thereto. For example, the pixel 52 may be configured by a combination of a yellow light-emitting element, a cyan light-emitting element, and a white light-emitting element, and may be configured by light-emitting elements of at least one color.

[0055] FIG. 6(B) is a partial cross-sectional view taken along line AB in FIG. 6(A). The pixel 52 is an organic EL element having an anode 54, a hole transport layer 55, any one of the light-emitting layers 56R, 56G, and 56B, an electron transport layer 57, and a cathode 58 on a substrate 53. Among these, the hole transport layer 55, the light-emitting layers 56R, 56G, and 56B, and the electron transport layer 57 correspond to organic layers. In this embodiment, the light-emitting layer 56R is an organic EL layer that emits red light, the light-emitting layer 56G is an organic EL layer that emits green light, and the light-emitting layer 56B is an organic EL layer that emits blue light. The light-emitting layers 56R, 56G, and 56B 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 anode 54 is formed separately for each light-emitting element. The hole transport layer 55, the electron transport layer 57, and the cathode 58 may be formed in common with the plurality of light emitting layers 56R, 56G, and 56B, or may be formed for each light emitting element. In order to prevent the anode 54 and the cathode 58 from being shorted due to foreign matter, an insulating layer 59 is provided between the electrodes. Furthermore, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer PL is provided to protect the organic EL element from moisture and oxygen.

[0056] 6(B), the hole transport layer 55 and the electron transport layer 57 are shown as a single layer, but may be formed of multiple layers including a hole blocking layer and an electron blocking layer depending on the structure of the organic EL element. In addition, a hole injection layer having an energy band structure for smoothly injecting holes from the anode 54 to the hole transport layer 55 may be formed between the anode 54 and the hole transport layer 55. Similarly, an electron injection layer may be formed between the cathode 58 and the electron transport layer 57.

[0057] A method for manufacturing an organic EL display device will now be described.

[0058] First, a substrate 53 on which a circuit (not shown) for driving the organic EL display device and an anode 54 are formed is prepared.

[0059] Next, acrylic resin is formed by spin coating on the substrate 53 on which the anode 54 has been formed, and patterned by lithography so as to form an opening in the portion of the acrylic resin where the anode 54 has been formed, to form an insulating layer 59. Such an opening corresponds to a light-emitting region where the light-emitting element actually emits light.

[0060] The substrate 53 with the patterned insulating layer 59 is carried into the film forming apparatus 1 (first film forming chamber) of the production line 100, and a hole transport layer 55 is formed as a common layer on the anode 54 of the display region 51. The hole transport layer 55 is formed by, for example, vacuum deposition. Since the hole transport layer 55 is actually formed to have a size larger than the display region 51, no high-definition mask is required.

[0061] Next, the substrate 53 on which the hole transport layer 55 has been formed is carried into the film formation apparatus 1 (second film formation chamber). The substrate 53 and a mask are aligned, and a red light emitting layer 56R is formed through the mask on a portion of the substrate 53 where a red light emitting element is to be formed.

[0062] Similar to the formation of the light-emitting layer 56R, the light-emitting layer 56G emitting green light is formed in the film formation apparatus 1 (third film formation chamber), and further, the light-emitting layer 56B emitting blue light is formed in the film formation apparatus 1 (fourth film formation chamber). After the light-emitting layers 56R, 56G, and 56B are formed, the electron transport layer 57 is formed over the entire display area 51 in the film formation apparatus 1 (fifth film formation chamber). The electron transport layer 57 is formed as a layer common to the three light-emitting layers 56R, 56G, and 56B.

[0063] Next, the substrate 53 on which the electron transport layer 57 has been formed is carried into the film formation apparatus 1 (sixth film formation chamber), and the cathode 58 is formed thereon.

[0064] Then, the substrate 53 on which the cathode 58 has been formed is carried into a sealing device, and the protective layer PL is formed by plasma CVD (sealing process), completing the organic EL display device 50. Here, the protective layer PL is formed by the CVD method, but the method is not limited to this. For example, the protective layer PL may be formed by the ALD method or the inkjet method.

[0065] If the substrate 53 on which the insulating layer 59 is patterned is exposed to an atmosphere containing moisture or oxygen during the period from when the substrate 53 is carried into the film forming apparatus 1 until when the protective layer PL is formed, the light emitting layer made of an organic EL material may deteriorate. Therefore, the substrate 53 is preferably carried in and out of the film forming apparatus in a vacuum atmosphere or an inert gas atmosphere.

[0066] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0067] 1: Film forming device 8: Alignment device 101: Substrate 101A: Film forming surface 101B: Back surface 102: Mask 102A: Opposing surface 102C: Pattern portion 102D: Protruding portion 102E: Top surface CR: Camera M1: First mark M2: Second mark

Claims

1. 1. An alignment apparatus used for aligning a substrate with a mask for depositing a pattern on a deposition surface of the substrate, comprising: a camera disposed on the opposite side of the mask when the substrate and the mask are superimposed on each other, the camera detecting a first mark provided on a back surface of the substrate opposite to the deposition surface and a second mark provided on the mask; the mask includes a pattern portion including an opening for depositing the pattern, and a protrusion protruding from an outer edge of an opposing surface facing the deposition surface of the pattern portion on a side on which the substrate is superimposed, The camera detects the second mark provided on an upper surface of the protrusion. An alignment apparatus comprising:

2. 2. The alignment apparatus according to claim 1, wherein the protrusion is provided on the outer edge portion so as to protrude along a side surface of the substrate when the substrate and the mask are superimposed on each other.

3. 2. The alignment apparatus according to claim 1, wherein the first mark is provided on the rear surface so as to be within a range of a field of view of the camera when the substrate and the mask are superimposed.

4. 4. The alignment apparatus according to claim 3, wherein the first mark and the second mark are provided on the back surface and the outer edge portion, respectively, so as to fall within a range of a depth of field of the camera when the substrate and the mask are superimposed.

5. 5. The alignment apparatus according to claim 4, wherein a protrusion amount of the protrusion portion is set so that the second mark falls within the range of the depth of field when the substrate and the mask are superimposed and the first mark falls within the range of the depth of field.

6. 5. The alignment apparatus according to claim 4, wherein the amount of protrusion of the protrusion is set to be ±5% of the sum of the thickness of the substrate and the gap between the substrate and the mask when the substrate and the mask are superimposed.

7. 5. The alignment device according to claim 4, wherein the protrusion amount of the protrusion is set so that, when the substrate and the mask are superimposed, the height position of the rear surface of the substrate coincides with the height position of the upper surface of the protrusion.

8. a first electrostatic chuck that attracts the back surface to hold the substrate; the first electrostatic chuck includes a structure for exposing the first mark at a portion corresponding to the first mark while the first electrostatic chuck holds the substrate; 2. The alignment apparatus according to claim 1, wherein:

9. The alignment apparatus of claim 8 , wherein the structure includes a through hole or a notch.

10. a second electrostatic chuck that attracts the upper surface to hold the mask; the second electrostatic chuck includes a structure for exposing the second mark at a portion corresponding to the second mark while holding the mask; 2. The alignment apparatus according to claim 1, wherein:

11. The alignment apparatus of claim 10 , wherein the structure includes a through hole or a notch.

12. a first electrostatic chuck that attracts the back surface of the substrate to hold the substrate; a second electrostatic chuck that attracts the upper surface to hold the mask; and the first electrostatic chuck holds the substrate such that the first mark is exposed; the second electrostatic chuck holds the mask such that the second mark is exposed; 2. The alignment apparatus according to claim 1, wherein:

13. 2. The alignment apparatus according to claim 1, wherein the camera detects the first mark and the second mark using visible light.

14. 1. An alignment method for aligning a substrate and a mask for depositing a pattern on a deposition surface of the substrate, comprising: Detecting a first mark provided on the substrate and a second mark provided on the mask using an alignment apparatus according to claim 1; aligning the substrate and the mask based on a result of detecting the first mark and the second mark; An alignment method comprising the steps of:

15. A film forming apparatus for forming a film on a substrate through a mask, 14. An alignment apparatus according to claim 1, which aligns the substrate and the mask. A film forming apparatus comprising:

16. A method for producing an electronic device, comprising the steps of: forming a film on a substrate;

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