CN114622160A

CN114622160A - Alignment apparatus, film forming apparatus, alignment method, film forming method, and method for manufacturing electronic device

Info

Publication number: CN114622160A
Application number: CN202111503460.2A
Authority: CN
Inventors: 神田宽
Original assignee: Canon Tokki Corp
Current assignee: Canon Tokki Corp
Priority date: 2020-12-11
Filing date: 2021-12-10
Publication date: 2022-06-14
Also published as: KR20220083624A; JP2022093003A

Abstract

The invention provides a technology capable of realizing high-precision alignment through a simple structure. The alignment device is provided with: a position acquisition mechanism for acquiring the relative position deviation amount of a substrate mark (71) at the corner of a substrate (5) and a mask mark (72) at the corner of a mask (220) imaged by an imaging mechanism (260), and a position adjustment mechanism for adjusting the relative position of the substrate and the mask, wherein the position adjustment mechanism performs the alignment of the position adjustment operation before the substrate is placed on the mask in such a manner that the pre-placement relative position deviation amount acquired by the position acquisition mechanism is within a predetermined range, and the position acquisition mechanism acquires the post-placement relative position deviation amount after the substrate is placed on the mask, and the imaging mechanism comprises: a first imaging unit (261) having a first imaging magnification; a second imaging unit (262) having a second imaging magnification that is greater than the first imaging magnification; an objective lens (416) commonly used in the first and second imaging sections.

Description

Alignment apparatus, film forming apparatus, alignment method, film forming method, and method for manufacturing electronic device

Technical Field

The invention relates to an alignment apparatus, a film forming apparatus, an alignment method, a film forming method, and a method of manufacturing an electronic device.

Background

In the manufacture of a flat panel display which has been made larger and thinner as in the case of an organic EL display in recent years, the deflection of the larger substrate due to its own weight greatly affects the alignment (alignment) of the substrate and the mask. Alignment is performed by checking a relative position deviation of alignment marks provided on the substrate and the mask, respectively, using an imaging mechanism such as a camera. Patent document 1 discloses a technique for increasing the efficiency of the process by performing alignment with gradually increasing accuracy. Specifically, first alignment (rough alignment) using a camera of low magnification is performed as rough alignment, and then second alignment (fine alignment) using a camera of high magnification is performed as alignment with improved accuracy.

[ Prior art documents ]

[ patent document ]

[ patent document 1 ] International publication No. 2017/222009

Disclosure of Invention

[ problem to be solved by the invention ]

In the technique disclosed in patent document 1, an alignment mark for rough alignment and an alignment mark for fine alignment are provided separately. Therefore, the number of alignment marks is required for the number of steps, and the number of alignment marks is also generated due to contamination in the film forming chamber.

In the technique disclosed in patent document 1, the alignment mark for rough alignment is disposed in the center portion where the peak of deflection is formed in the peripheral portion of the substrate, and the alignment mark for precise alignment is disposed in the end portion where deflection is small in the peripheral portion of the substrate. The rough alignment is performed in a state where the substrate is lifted up with respect to the mask, and the fine alignment is performed in a state where a part of the substrate is placed on the mask in contact with the mask. Here, the way of the flexure of the substrate changes depending on the vibration or the fluctuation of the center of gravity when moving up and down with respect to the mask, or depending on the contact/non-contact with the mask, and the magnitude of the fluctuation of the flexure also differs depending on the portion of the substrate. In this way, the influence of the magnitude of the amount of positional deviation obtained at the time of alignment on the positional deviation at the time of final mask mounting differs between, for example, the central portion where the variation in deflection is large and the end portion where the variation is small in the peripheral portion of the substrate. That is, if the position where the misalignment is confirmed in the alignment is different, the meaning of the magnitude of the misalignment is also different, which makes it difficult to determine the adjustment amount of the alignment.

The invention aims to provide a technology capable of realizing high-precision alignment through a simple structure.

[ MEANS FOR solving PROBLEMS ] A method for solving the problems

In order to solve the above problem, an alignment device according to the present invention includes:

a substrate holding mechanism having a support portion for supporting a peripheral edge portion of a rectangular substrate;

a mask holding mechanism that holds a rectangular mask;

a position acquisition unit having an imaging unit for imaging a substrate mark provided at a corner of the substrate and a mask mark provided at a corner of the mask, the position acquisition unit acquiring a relative positional deviation between the substrate mark and the mask mark imaged by the imaging unit; and

a position adjusting mechanism that controls at least one of the substrate holding mechanism and the mask holding mechanism to perform a position adjusting operation of adjusting a relative position between the substrate held by the substrate holding mechanism and the mask held by the mask holding mechanism,

the position adjusting means performs the alignment of the position adjusting operation so that the relative positional deviation amount before the substrate is placed on the mask, the relative positional deviation amount being acquired by the position acquiring means, falls within a predetermined range,

the position acquiring means acquires a relative positional deviation amount after the substrate is placed on the mask, and the alignment apparatus is characterized in that,

the imaging mechanism includes: a first imaging unit having a first imaging magnification; a second imaging unit having a second imaging magnification larger than the first imaging magnification; and an objective lens commonly used in the first and second image pickup sections.

[ Effect of the invention ]

According to the present invention, high-precision alignment can be achieved by a simple structure.

Drawings

Fig. 1 is a schematic view of a production line of electronic devices including a film forming apparatus.

Fig. 2 is a sectional view showing an internal structure of the film formation apparatus.

Fig. 3 is a perspective view showing a substrate chucking apparatus in the film deposition apparatus.

Fig. 4 is a diagram illustrating the structure of the imaging mechanism.

Fig. 5 is a schematic view showing the alignment and mounting in the embodiment.

Fig. 6 is a flowchart showing a flow of processing in the embodiment.

Fig. 7 is a diagram illustrating a method of manufacturing an electronic device.

[ description of reference ]

210 … substrate holding unit, 220 … mask, 221 … mask stage, 260 … camera unit, 261 … first camera, 262 … second camera, 416 … objective lens, 5 … substrate, 71 … substrate alignment mark, 72 … mask alignment mark

Detailed Description

(example 1)

Hereinafter, a mode for carrying out the present invention will be described in detail based on examples with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiment are not intended to limit the scope of the present invention to these unless otherwise specified.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. However, the following description is merely exemplary of preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. In the following description, the hardware configuration and software configuration of the device, the process flow, the manufacturing conditions, the dimensions, the materials, the shapes, and the like are not intended to limit the scope of the present invention to these embodiments unless otherwise specified.

When a film having a desired pattern is formed on a substrate, a mask having a mask pattern adapted to the shape of the film is used. By using a plurality of masks, each layer to be formed can be arbitrarily configured. In order to form a film at a desired position on a substrate, it is necessary to align the relative position of the substrate or the like and a mask with high accuracy.

The present invention is suitably applied to a structure for aligning a substrate with a mask as described above. Therefore, the present invention can be grasped as an alignment apparatus or an alignment method for a substrate and a mask. The present invention can also be grasped as a film deposition apparatus or a film deposition method using the above-described alignment apparatus or alignment method. The present invention can also be grasped as an apparatus for manufacturing an electronic device or a method for manufacturing an electronic device using the above-described film deposition apparatus or film deposition method. The present invention can also be grasped as a method for controlling each of the above-described devices.

The present invention can be preferably applied to a case where a thin film material layer having a desired pattern is formed on a surface of a substrate through a mask. As a material of the substrate, any material such as glass, resin, metal, and silicon can be used. As the film forming material, any material such as an organic material or an inorganic material (metal or metal oxide) can be used. The technique of the present invention is typically applied to an apparatus for manufacturing an electronic device or an optical member. In particular, the organic EL display is suitable for organic electronic devices such as an organic EL display, an organic EL display device using the organic EL display, a thin-film solar cell, and an organic CMOS image sensor. However, the applicable objects of the present invention are not limited thereto.

< example 1>

(production line of electronic devices)

Fig. 1 is a plan view schematically showing the structure of a production line for electronic devices. Such a production line can be said to be a film formation system including a film formation apparatus. Here, a production line of the organic EL display is explained. In the case of manufacturing an organic EL display, a substrate having a predetermined size is carried into a production line, and after organic EL and a metal layer are formed, a post-treatment process such as dicing is performed on the substrate.

As shown in fig. 1, the film formation cluster 1 of the production line includes a transfer chamber 130 disposed at the center, and a film formation chamber 110 and a mask storage chamber 120 disposed around the transfer chamber 130. The film forming chamber 110 includes a film forming apparatus and performs a film forming process on the substrate 5. The mask storage chamber 120 stores masks before and after use. The transfer robot 140 provided in the transfer chamber 130 carries the substrate 5 or the mask 220 into and out of the transfer chamber 130. The transfer robot 140 is, for example, a robot having a multi-joint arm to which a robot hand holding the substrate 5 or the mask 220 is attached.

The passage chamber 150 conveys the substrate 5, which is conveyed from the upstream side in the substrate conveying direction, toward the conveying chamber 130. The buffer chamber 160 conveys the substrate 5, which has been subjected to the film formation process by the film formation cluster, to another film formation cluster on the downstream side. The transfer robot 140 transfers the substrate 5 to one of the plurality of film forming chambers 110 when receiving the substrate from the passage chamber 150. The transfer robot 140 also receives the substrate 5 having undergone the film formation process from the film formation chamber 110, and transfers the substrate to the buffer chamber 160. A swirl chamber 170 for changing the direction of the substrate 5 is provided further upstream of the passage chamber 150 or further downstream of the buffer chamber 160. The chambers such as the film forming chamber 110, the mask storage chamber 120, the transfer chamber 130, the buffer chamber 160, and the whirling chamber 170 are maintained in a high vacuum state during the process of manufacturing the organic EL display panel.

(film Forming apparatus)

FIG. 2 is a sectional view showing the structure of a film forming apparatus. Each of the plurality of film forming chambers 110 is provided with a film forming device 108 (also referred to as a vapor deposition device). The film forming apparatus 108 performs a series of film forming processes such as transfer to and from the substrate 5 by the transfer robot 140, alignment (positional alignment) for adjusting a relative positional relationship between the substrate 5 and the mask 220, mounting and fixing of the substrate 5 on the mask 220, and film formation (vapor deposition).

In the following description, an XYZ rectangular coordinate system in which the vertical direction is the Z direction is used. In the XYZ rectangular coordinate system, when the substrate is fixed so as to be parallel to a horizontal plane (XY plane) at the time of film formation, a direction in which one of two opposing sets of sides of the rectangular substrate 5 extends is defined as an X direction, and a direction in which the other set of sides extends is defined as a Y direction. Also, the rotation angle around the Z axis is represented by θ.

The film formation device 108 includes a vacuum chamber 200. The inside of the vacuum chamber 200 is maintained in an inert gas atmosphere such as a vacuum atmosphere or nitrogen gas. The vacuum chamber 200 is provided therein with a substrate holding unit 210, a mask 220, a mask stage 221, a cooling plate 230, and an evaporation source 240.

The substrate holding unit 210 (substrate holding mechanism) has a function as a support for supporting the substrate 5 received from the transfer robot 140. The mask 220 is, for example, a metal mask, and is provided with an opening corresponding to a thin film pattern formed on the film formation surface of the substrate 5. The mask 220 is provided on a frame-shaped mask stage 221 (mask holding mechanism) as a mask supporting unit. In the structure of the present embodiment, after the substrate 5 is placed on, positioned, and supported by the mask 220, film formation is performed.

The cooling plate 230 (cooling portion) is a plate-shaped member that comes into contact with a surface of the substrate 5 opposite to a surface (film formation target surface) in contact with the mask 220 during film formation, and suppresses an increase in temperature of the substrate 5 during film formation. The cooling plate 230 cools the substrate 5, thereby suppressing the deterioration or degradation of the organic material. The cooling plate 230 may also serve as a magnet plate. The magnet plate attracts the mask 220 by magnetic force, thereby improving the adhesion between the substrate 5 and the mask 220 during film formation. In order to improve the adhesion between the substrate 5 and the mask 220, the substrate holding unit 210 may hold both the substrate 5 and the mask 220 and adhere them to each other by an actuator or the like.

The evaporation source 240 is a film forming mechanism including a container such as a crucible for containing a vapor deposition material, a heater, a shutter, a driving mechanism, an evaporation rate monitor, and the like. Here, a vapor deposition apparatus using the evaporation source 240 as a film formation source is shown, but the present invention is not limited thereto. For example, the film forming apparatus 108 may be a sputtering apparatus using a sputtering target as a film forming source.

A substrate Z actuator 250, a clamp Z actuator 251, and a cooling plate Z actuator 252 are provided on the outer upper portion of the vacuum chamber 200. Each actuator is composed of, for example, a motor and a ball screw, a motor and a linear guide, and the like. An alignment stage 280 is further provided at an outer upper portion of the vacuum chamber 200.

The substrate Z actuator 250 (moving mechanism) drives the entire substrate holding unit 210 in the Z-axis direction to move up and down. Thus, the relative distance between the substrate 5 and the mask 220 changes in a direction (intersecting direction, typically, a direction perpendicular to the plane of the film formation surface of the substrate 5) intersecting the plane of the film formation surface of the substrate 5 (substrate mounting surface of the mask 220). The clamp Z actuator 251 (driving mechanism) drives the pressing tool of the substrate holding unit 210 to open and close.

The cooling plate Z actuator 252 (cooling drive mechanism) drives and moves up and down the cooling plate 230. Before film formation, the cooling plate Z actuator 252 lowers the cooling plate 230 so as to contact the surface of the substrate 5 opposite to the film formation surface. In addition, by pressing the substrate 5 with the cooling plate 230 during film formation, a secondary effect is obtained in which the peripheral edge of the substrate 5 is not displaced even without being sandwiched. The timing and distance for lowering the cooling plate 230 are not limited as long as they do not interfere with the movement of the substrate 5, and they may be brought into contact with the substrate 5 during film formation.

(Structure for alignment)

The alignment stage 280 is an alignment device that moves the substrate 5 in the XY direction and rotates the substrate in the θ direction to change the position of the substrate and the mask 220. The alignment stage 280 is a position adjustment mechanism for adjusting the relative position of the substrate 5 and the mask 220 in a plane along the film formation surface of the substrate 5. The alignment stage 280 includes a chamber fixing portion 281 connected and fixed to the vacuum chamber 200, an actuator portion 282 for performing XY θ movement, and a connecting portion 283 connected to the substrate holding unit 210. The alignment stage 280 may be considered as an alignment device for aligning the substrate holding unit 210. Further, the alignment stage 280 and the substrate holding unit 210 may be considered as an alignment device by adding the controller 270 thereto.

As the actuator unit 282, an actuator in which an X actuator, a Y actuator, and a θ actuator are stacked may be used. Further, a UVW type actuator in which a plurality of actuators cooperate may be used. In any of the above-described methods, the actuator unit 282 is driven in accordance with a control signal transmitted from the control unit 270 to move the substrate 5 in the X direction and the Y direction and rotate the substrate in the θ direction. The control signal indicates the operation amount of each actuator of XY θ in the case of the actuator of the stack system, and indicates the operation amount of each actuator of UVW in the case of the actuator of the UVW system.

The alignment stage 280 moves the substrate holding unit 210 XY θ. In this embodiment, the position of the substrate 5 is adjusted, but the position of the mask 220 or both the substrate 5 and the mask 220 may be adjusted, so long as the substrate 5 and the mask 220 can be aligned with each other.

An imaging unit 260 as imaging means for performing optical imaging to generate image data is provided on the outer upper portion of the vacuum chamber 200. The imaging unit 260 performs imaging through the imaging window 206 (see fig. 4) provided in the vacuum chamber 200. A vacuum sealing window is used to maintain the chamber airtight.

The controller 270 analyzes captured image data obtained by the imaging unit 260 during alignment, and obtains positional information of a substrate alignment mark (substrate mark) and a mask alignment mark (mask mark) by a method such as pattern matching. The controller 270 calculates the XY direction, distance, and angle θ for moving the substrate 5 based on the amount of positional deviation between the substrate alignment mark and the mask alignment mark. Then, the calculated movement amount is converted into a driving amount of a stepping motor, a servo motor, or the like provided in each actuator of the alignment stage 280, and a control signal is generated.

Typically, the substrate alignment marks are formed on the substrate by photolithography, and each mask alignment mark is formed on the mask by machining. However, the method of forming the mark is not limited to this, and may be selected according to the material and purpose. The shape and size of the mark may be set according to the performance of the camera and the capability of image analysis.

The controller 270 performs alignment control based on operation control of the actuators by the actuator unit 282, loading/unloading control of the substrate 5 and the mask 220, film formation control, and other various controls. The control unit 270 may be configured by a computer having a processor, a memory, a register, an I/O, and the like, for example. In this case, the function of the control unit 270 is realized by the processor executing a program stored in a memory or a register. As the computer, a general-purpose personal computer may be used, or an embedded computer or a PLC (programmable logic controller) may be used. Alternatively, a part or all of the functions of the control unit 270 may be configured by a circuit such as an ASIC or FPGA. The controller 270 may be provided for each of the film forming apparatuses, or one controller 270 may control a plurality of film forming apparatuses.

(substrate holding unit)

A configuration example of the substrate holding unit 210 is explained with reference to the perspective view of fig. 3. The substrate holding unit 210 includes: a support frame 301 provided with a plurality of support tools 300 (support parts) for supporting the respective sides of the substrate 5; a clamping member 303 is provided with a plurality of pressing tools 302 (pressing parts) for sandwiching the substrate 5 between the supporting tools 300. The pair of supporting tool 300 and the pressing tool 302 constitute a gripping mechanism. Upon receiving the drive of the chuck Z actuator 251, the pressing tool 302 is driven to a pressing state (chuck state) in which it is opposed to the corresponding supporting tool 300 and presses the peripheral edge portion of the substrate 5, and a separated state in which it is separated from the substrate 5. However, the number and arrangement of the chucking mechanisms are not limited to these, and the substrate 5 may be held while being pressed (pressed state) or released by releasing the pressing of the substrate 5 (separated state) by driving the chuck Z actuator 251. The term "pressing" as used herein includes not only a case where the pressing tool 302 applies a predetermined biasing force to the peripheral edge of the substrate to press the peripheral edge of the substrate, but also a case where the pressing tool 302 and the supporting tool 300 are fixed to each other with a predetermined nip width and the peripheral edge of the substrate is pressed from above. In the present specification, the substrate 5 is also expressed in a pressed state (clamped state) or a separated state according to the pressed state and the separated state of the pressing tool 302, respectively. In the present embodiment, even in the state where the pressing is released, the substrate 5 can be moved in the Z direction or the XY direction, or rotated in the θ direction as long as the substrate 5 is placed on and supported by the supporting tool 300.

The alignment stage 280 adjusts the relative position of the substrate 5 with respect to the mask 220 by transmitting a driving force to the substrate holding unit 210 in a state where the substrate 5 is supported, and moving the substrate 5 relative to the mask 220. In the Z-direction movement of the substrate 5, the substrate Z actuator 250 is driven to move the substrate holding unit 210 and raise and lower the substrate 5. Thereby, the substrate 5 approaches or separates from the mask 220. In the XY movement or θ rotation of the substrate 5, the alignment stage 280 linearly moves the substrate 5 in the XY direction or rotationally moves in the θ direction. The substrate 5 is moved in the XY plane in which the substrate is arranged, and the XY plane is substantially parallel to the plane in which the mask is arranged. That is, the substrate 5 does not change in the Z-direction distance from the mask 220 during XY movement and θ rotation of the substrate 5, and the position of the substrate 5 changes in the XY plane. Thereby, the substrate 5 and the mask 220 are aligned in the XY plane.

(shooting unit)

Fig. 4 is a schematic cross-sectional view schematically showing the structure of the imaging unit 260 of the present embodiment. The photographing unit 260 is a so-called dual-lens single-view camera. The imaging unit 260 roughly has: an illumination unit 400 for irradiating detection light toward the periphery of the alignment mark; a first camera 261 as a first photographing section; a second camera 262 as a second photographing section; and an objective lens 416 common to both cameras. The first camera 261 and the second camera 262 capture an image of a region including the alignment mark (substrate mark) 71 of the substrate 5 and the alignment mark (mask mark) 72 of the mask 220 via the common objective lens 416.

The substrate marks 71 are provided at respective corner portions (four corner portions) of the rectangular substrate 5, and the mask marks 72 are also provided at respective corner portions (four corner portions) of the rectangular mask 220. The mask mark 72 is subjected to fluoroscopic imaging through the substrate 5. That is, the imaging unit 260 is disposed so as to include the substrate mark 71 on the surface of the substrate 5 and the mask mark 72 on the surface of the mask 220 in the common imaging region of the first camera 261 and the second camera 262. In the present embodiment, four photographing units 260 are provided corresponding to four corner portions of the substrate 5 and the mask 220. However, the number and installation location of the alignment marks, and the number, installation location, and type of cameras are not limited to this example.

The illumination unit 400 irradiates the detection light emitted from the LED401 as a light source toward the periphery of the corner portion of the substrate 5 (the periphery of the substrate mark 71) via the half mirror 417 and the imaging window 206. The illumination unit 400 irradiates auxiliary light from an LED402 as an auxiliary light source toward the periphery of the corner portion of the substrate 5 through the imaging window 206. The corner portion of the mask 220 (the periphery of the mask mark 72) overlaps the corner portion of the substrate 5 in the mounting direction of the substrate 5 with respect to the mask 220 (the direction perpendicular to the mounting surface of the substrate 5 on the mask 220), and the detection light or the auxiliary light is irradiated through the corner portion of the substrate 5.

The first camera 261 and the second camera 262 capture reflected light from a corner portion (a corner portion of the mask 220) of the substrate 5 via the common objective lens 416. The imaging unit 260 has a branched optical path forming portion 410 that forms an optical path of the reflected light. The branched optical path forming section 410 includes: a common optical path provided with an objective lens 416; a first branch optical path forming the low-magnification photographing section 461 together with the first camera 261; and a second branched optical path forming the high-magnification imaging section 462 together with the second camera 262. The first branch optical path causes the reflected light introduced through the objective lens 416 and the relay lens 415 to be captured by the first camera 261 through the

prisms

414 and 413, the relay lens 412, and the low-magnification lens 411. The second branch optical path causes the reflected light introduced through the objective lens 416 and the relay lens 415 to be captured by the second camera 262 through the prism 414 and the high-power lens 421.

In this embodiment, the conventional two-stage alignment is not performed, and only the alignment using the first camera 261 is performed before the substrate 5 is placed on the mask 220. After the substrate 5 is placed on the mask 220, the second camera 262 is used to finally confirm the relative position between the substrate 5 and the mask 220 (relative position after placement) before film formation.

The first camera 261 used for alignment is a camera including a low-magnification imaging element (a two-dimensional image element such as a MOS or CCD) having a lower resolution and a wider field of view than the second camera 262. The first camera 261 for alignment in this embodiment may be a camera having the same performance as that of the camera used for coarse alignment in the conventional two-stage alignment (coarse alignment, fine alignment). In the present embodiment, as the first camera 261 having the first photographing magnification, for example, a magnification: x 0.67 times, field of view: 12.6mm × 10.5mm, depth of field: 8.54mm camera.

The second camera 262 used for measurement before film formation is a camera including a high-magnification imaging device (a two-dimensional image device such as a MOS or a CCD) having a narrower field of view and a higher resolution than the first camera 261. The second camera 262 for confirming the relative position after mounting in the present embodiment can use a camera having the same performance as that of the camera used for the fine alignment in the conventional two-stage alignment (coarse alignment, fine alignment). In the present embodiment, as the second camera 262 having the second photographing magnification larger than the first photographing magnification, for example, a magnification: x 2.44 times, field of view: 3.5mm × 2.9mm, depth of field: 0.57mm camera.

(alignment and measurement before film formation)

Referring to fig. 5 and 6, alignment processing and pre-film-formation misalignment measurement processing of the substrate 5 with respect to the mask 220 will be described. Fig. 5 is a schematic diagram schematically showing alignment and measurement before film formation. Fig. 6 is a flowchart showing the steps of alignment and measurement before film formation. Fig. 5 schematically shows only the internal structure of the film deposition apparatus, which is related to alignment or pre-film deposition processing. Then, the present flow shown in fig. 6 starts with the mask 220 being loaded from the mask storage chamber 120 and set on the mask stage 221.

In step S101, the transfer robot 140 carries the substrate 5 from the passage chamber 150 into the film forming chamber 110. When the peripheral edge (end) of the substrate 5 is placed on the supporting tool 300, the transfer robot 140 is retracted from the film forming chamber 110. As a result, as shown in fig. 5(a), the substrate 5 is supported by the supporting tool 300. In the present embodiment, the clamping by the pressing tool 302 is not performed at the stage of this step, but may be performed.

In step S102, the substrate Z actuator is driven to lower the substrate holding unit 210 in a state where the substrate 5 is supported by the supporting tool 300. The movement of the substrate 5 is stopped at a predetermined height at which the substrate 5 does not contact the mask 220, and a predetermined height (interval) h is secured between the lowermost end portion (the portion that protrudes downward due to the flexure) of the substrate 5 and the mask 220. The height h is a height at which the substrate mark 71 and the mask mark 72 can be photographed in alignment using the first camera 261, which will be described later.

In step S103, the clamp Z actuator 251 drives the pressing tool 302 to bring the substrate 5 into a clamped state. That is, the pressing tool 302 of the substrate holding unit is lowered to press the peripheral edge of the substrate at a position facing the supporting tool 300, and the peripheral edge of the substrate is sandwiched between the supporting tool 300 and the substrate. As a result, as shown in fig. 5(a), the peripheral edge of the substrate 5 is clamped.

In step S104, alignment using the first camera 261 is performed. That is, in a state where the substrate 5 and the mask 220 are not in contact, the substrate mark 71 and the mask mark 72 are imaged by the first camera 261 of low magnification. Relative positions of the two marks on a plane parallel to the substrate mounting surface of the mask 220 (relative positions before mounting) are acquired from the captured image, thereby acquiring the amount of positional deviation between the substrate 5 and the mask 220 (first acquisition step). Specifically, the controller 270 analyzes the image as a position acquisition means, and calculates the amount of positional deviation based on the distance and angle between the alignment marks of the substrate 5 and the mask 220. Then, the alignment stage 280 (fig. 2) corrects the positional deviation by XY-moving and θ -rotating the substrate 5 (position adjustment step). When the operation of the alignment stage 280 is finished, the first camera 261 again captures the alignment marks, and the control unit 270 determines whether or not the amount of positional deviation between the marks falls within a predetermined threshold. If the threshold value is exceeded, the alignment by the alignment stage 280 is performed again. By repeating the alignment in this manner until the amount of positional deviation falls within the threshold value, the alignment is completed.

In step S105, the substrate Z actuator is driven to lower the substrate holding unit 210 in a state where the substrate 5 is clamped, and stops at a position where the supporting surface of the supporting tool 300 has the same height as the upper surface (substrate mounting surface) of the mask 220 (mounting step). That is, the substrate 5 is moved to a position where the film formation surface thereof is overlapped with the upper surface of the mask 220. Then, the cooling plate Z actuator 252 is driven to lower the cooling plate 230 to be in close contact with the upper surface (the surface opposite to the film formation surface) of the substrate 5, and the substrate 5 is sandwiched vertically by the mask 220 and the cooling plate 230. Then, the clamped state by the substrate holding unit 210 is released, that is, the pressing tool 302 is retracted upward, and the supporting tool 300 is retracted downward. After the film formation surface of the substrate 5 is superimposed on the upper surface of the mask 220, the clamped state by the substrate holding unit 210 can be released before the cooling plate 230 is brought into close contact with the film.

In step S106, as measurement before film formation, as shown in fig. 5(b), the substrate mark 71 and the mask mark 72 are imaged by the second camera 262 of high magnification in a state where the substrate 5 is placed on the mask 220. That is, the controller 270 images the alignment marks at the corner portions of the substrate 5 and the mask 220 using the second camera 262, analyzes the image captured by the second camera 262, and acquires the amount of positional deviation between the substrate 5 and the mask 220 (second acquisition step). Then, the obtained amount of positional deviation is compared with a predetermined threshold value to determine whether or not the amount is within the allowable range. If the range is out of the allowable range, the alignment of S104 is performed again.

When the amount of positional deviation between the substrate 5 and the mask 220 is out of the allowable range of the threshold value (S107: NO), the alignment in S104 is performed again. That is, the cooling plate 230 is retracted upward, the substrate holding unit 210 is raised to support the peripheral edge of the substrate by the support tool 300, the substrate 5 is raised from the mask 220, and the flow returns to S104.

When the amount of positional deviation between the substrate 5 and the mask 220 is within the threshold value, that is, when the amount of positional deviation after mounting obtained from the relative position between the substrate 5 and the mask 220 after mounting (the relative position after mounting) falls within a predetermined range (yes in S107), the alignment process and the mounting process are completed. In this way, the process proceeds to step S108, and the film formation process is started. That is, the evaporation source 240 generates heat, and the film material is scattered and attached to the substrate 5 through the mask 220, thereby forming a film corresponding to the mask pattern on the lower surface of the substrate 5. After the film formation is completed, the transfer robot 140 sends out the substrate 5 on which the film formation is completed.

As described above, in the present embodiment, the same mark is captured by the low-magnification imaging unit and the high-magnification imaging unit using the two-lens single-field camera, the substrate and the mask are aligned without contact by the low-magnification imaging unit, and after the alignment, the same mark is captured by the high-magnification imaging unit and measurement before film formation is performed. According to the above configuration, the number of times of contact between the substrate and the mask during alignment can be reduced as compared with the case of performing rough alignment and fine alignment as in the related art, and damage to a film or an element formed in a central portion of the substrate and product defects can be particularly suppressed.

In conventional alignment, an alignment mark used for rough alignment and an alignment mark used for fine alignment are provided separately, and the positions where the alignment marks are arranged are set to positions where the difference in the degree of deflection is relatively large in the substrate. Specifically, the alignment mark for rough alignment is disposed in the center portion of the substrate peripheral portion where the peak of deflection is formed, and the alignment mark for fine alignment is disposed in the end portion of the substrate peripheral portion where deflection is small. The rough alignment is performed in a state where the substrate is floated with respect to the mask, but the fine alignment is performed in a state where a part of the substrate is placed on the mask while being in contact with the mask. That is, in a case where fine alignment is repeated, contact between the substrate and the mask is repeated, and the film or the like in the central portion of the substrate is damaged. Therefore, in order to reduce the number of times of fine alignment, it is required to perform coarse alignment with high accuracy. However, the way of the flexure of the substrate changes depending on the vibration or the fluctuation of the center of gravity when moving up and down with respect to the mask, or depending on the contact/non-contact with the mask, and the magnitude of the fluctuation of the flexure also differs depending on the portion of the substrate. That is, the influence of the amount of misalignment obtained during alignment on the misalignment during final mask placement differs between the central portion of the substrate peripheral portion where the deflection fluctuates greatly and the end portion where the fluctuation is small. Therefore, if the positions where the misalignment is confirmed differ during the alignment, the meaning of the magnitude of the misalignment also differs, which makes it difficult to determine the adjustment amount of the alignment. In addition, the operation of the substrate during flexural deformation and the like are also subject to individual differences between the substrate and the film deposition apparatus. That is, in the case where the coarse alignment is performed with high accuracy in order to reduce the number of times of the fine alignment, there is a limit in technical difficulty.

In contrast, in the present embodiment, the substrate and the mask are brought into non-contact, and only the alignment is performed in which the alignment mark arranged at the end portion with less deflection in the peripheral portion of the substrate is imaged using the low-magnification camera used in the rough alignment in the conventional alignment. By using a low-magnification camera with a wide depth of field, non-contact alignment can be performed in which the substrate is placed at a high position. Further, since the alignment mark is disposed at the peripheral edge portion of the substrate, which is relatively less affected by the flexure, alignment with higher accuracy than conventional rough alignment can be performed. Therefore, the positional deviation in the pre-film formation measurement for mounting the substrate on the mask is reduced, and the number of times of contact between the substrate and the mask before film formation can be reduced.

In the present embodiment, the alignment mark for detecting positional deviation during measurement before film formation is a mark common to the alignment mark used for alignment, and thus the number of alignment marks can be reduced as compared with the case of conventional stepwise alignment. Therefore, the cause of contamination in the film forming chamber can be reduced.

In the present embodiment, by using a two-lens single-view camera, the objective lens can be shared between the first camera for alignment and the second camera for measurement before film formation, and the number of components can be reduced.

< method for producing electronic device >

A method for manufacturing an electronic device using the film formation apparatus will be described. Here, a case of an organic EL element used in a display device such as an organic EL display device will be described as an example of an electronic device. The electronic device of the present invention is not limited to this, and may be a thin film solar cell or an organic CMOS image sensor. This embodiment includes a step of forming an organic film on the substrate 5 by using the above-described film formation method. The method further includes a step of forming a metal film or a metal oxide film after forming the organic film on the substrate 5. The structure of the organic EL display device 600 obtained through such a process will be described below.

Fig. 7(a) shows an overall view of the organic EL display device 600, and fig. 7(b) shows a cross-sectional structure of one pixel. As shown in fig. 7(a), in a display region 61 of the organic EL display device 600, a plurality of pixels 62 each including a plurality of light-emitting elements are arranged in a matrix. Each of the light-emitting elements has a structure including an organic layer sandwiched between a pair of electrodes. The pixel herein is a minimum unit that can display a desired color in the display region 61. In the case of the organic EL display device of the present figure, the pixel 62 is configured by a combination of the first light-emitting element 62R, the second light-emitting element 62G, and the third light-emitting element 62B which display mutually different light emissions. The pixel 62 is often configured by a combination of a red light emitting element, a green light emitting element, and a blue light emitting element, but may be a combination of a yellow light emitting element, a cyan light emitting element, and a white light emitting element, and is not particularly limited as long as it has at least one color. Each light-emitting element can be formed by stacking a plurality of light-emitting layers.

Further, the pixel 62 may be configured by a plurality of light emitting elements that emit the same light, and one pixel may be displayed with a desired color in the display region 61 by using a color filter in which a plurality of different color conversion elements are arranged in a pattern so as to correspond to the respective light emitting elements. For example, the pixel 62 may be configured by at least three white light emitting elements, and a color filter in which red, green, and blue color conversion elements are arranged so as to correspond to the respective light emitting elements may be used. Alternatively, the pixel 62 may be configured by at least three blue light emitting elements, and a color filter in which red, green, and colorless color conversion elements are arranged so as to correspond to the respective light emitting elements may be used. In the latter case, by using a Quantum Dot (QD-CF) filter using a QD material as a material constituting the color filter, the display color gamut can be widened compared with a general organic EL display device not using a QD filter.

Fig. 7(B) is a partial cross-sectional view at the line a-B of fig. 7 (a). The pixel 62 includes an organic EL element on the substrate 5, and the organic EL element includes a first electrode (anode) 64, a hole transport layer 65, any one of the light-emitting

layers

66R, 66G, and 66B, an electron transport layer 67, and a second electrode (cathode) 68. Among them, the hole transport layer 65, the

light emitting layers

66R, 66G, and 66B, and the electron transport layer 67 correspond to an organic layer. Further, in the present embodiment, the light-emitting layer 66R is an organic EL layer that emits red, the light-emitting layer 66G is an organic EL layer that emits green, and the light-emitting layer 66B is an organic EL layer that emits blue. In the case of using the color filter or the quantum dot color filter as described above, the color filter or the quantum dot color filter is disposed on the light emitting side of each light emitting layer, that is, on the upper or lower portion of fig. 7(b), but the illustration is omitted.

The light-emitting

layers

66R, 66G, and 66B are formed in patterns corresponding to light-emitting elements (also referred to as organic EL elements) that emit red, green, and blue light, respectively. The first electrode 64 is formed separately for each light emitting element. The hole transport layer 65, the electron transport layer 67, and the second electrode 68 may be formed in common with the plurality of

light emitting elements

62R, 62G, and 62B, or may be formed for each light emitting element. In order to prevent the first electrode 64 and the second electrode 68 from being short-circuited by impurities, an insulating layer 69 is provided between the first electrodes 64. Further, since the organic EL layer is deteriorated by moisture or oxygen, a protective layer P for protecting the organic EL element from moisture or oxygen is provided.

Next, an example of a method for manufacturing an organic EL display device as an electronic device will be specifically described. First, the substrate 5 on which the circuit (not shown) for driving the organic EL display device and the first electrode 64 are formed is prepared.

Next, a resin layer of acrylic resin, polyimide, or the like is formed on the substrate 5 on which the first electrodes 64 are formed by spin coating, and the resin layer is patterned by photolithography so as to form openings in portions where the first electrodes 64 are formed, thereby forming the insulating layer 69. The opening corresponds to a light-emitting region where the light-emitting element actually emits light.

Next, the substrate 5 on which the insulating layer 69 is patterned is sent to a first film forming apparatus, and the substrate is held by the substrate holding unit, and the hole transport layer 65 is formed as a common layer on the first electrode 64 in the display region. The hole transport layer 65 is formed by vacuum evaporation. In practice, the hole transport layer 65 is formed to have a size larger than that of the display region 61, and therefore a high-definition mask is not required. Here, the film forming apparatus used for film formation in this step or film formation of each layer described below is the film forming apparatus described in any one of the above embodiments.

Next, the substrate 5 on which the hole transport layer 65 has been formed is sent to the second film formation apparatus and held by the substrate holding means. The substrate is placed on the mask by aligning the substrate with the mask, and a light-emitting layer 66R emitting red light is formed on a portion of the substrate 5 where the elements emitting red light are disposed. According to this embodiment, the mask and the substrate can be satisfactorily superposed on each other, and a film can be formed with high accuracy.

Similarly to the formation of the light-emitting layer 66R, the light-emitting layer 66G emitting green light is formed by the third film-forming device, and the light-emitting layer 66B emitting blue light is formed by the fourth film-forming device. After the completion of the formation of the light-emitting

layers

66R, 66G, and 66B, the electron transport layer 67 is formed in the entire display region 61 by the fifth film formation device. The light-emitting

layers

66R, 66G, and 66B may be single layers, or may be a stack of a plurality of different layers. The electron transport layer 65 is formed as a common layer on the

light emitting layers

66R, 66G, and 66B of three colors. In this embodiment, the electron transport layer 67 and the

light emitting layers

66R, 66G, and 66B are formed by vacuum evaporation.

Next, the second electrode 68 was formed on the electron transit layer 67. The second electrode may be formed by vacuum evaporation or sputtering. Then, the substrate on which the second electrode 68 is formed is moved to a sealing device, and the protective layer P is formed by plasma CVD (sealing step), whereby the organic EL display device 600 is completed. The protective layer P is formed by a CVD method, but is not limited thereto, and may be formed by an ALD method or an inkjet method.

Until the substrate 5 on which the insulating layer 69 is formed is conveyed to a film forming apparatus until the formation of the protective layer P is completed, if the substrate is exposed to an atmosphere containing moisture and oxygen, the light-emitting layer made of an organic EL material may be deteriorated by moisture and oxygen. Therefore, in this example, the substrate is carried in and out between the film forming apparatuses in a vacuum atmosphere or an inert gas atmosphere.

Claims

1. An alignment device, comprising:

a mask holding mechanism that holds a rectangular mask;

a position acquiring unit having an imaging unit for imaging a substrate mark provided at a corner of the substrate and a mask mark provided at a corner of the mask, the position acquiring unit acquiring a relative positional deviation between the substrate mark and the mask mark imaged by the imaging unit; and

the position adjusting means performs the alignment of the position adjusting operation so that the relative positional displacement before mounting acquired by the position acquiring means is within a predetermined range before the substrate is mounted on the mask,

the alignment apparatus is characterized in that the position acquiring means acquires a relative positional deviation amount after the substrate is placed on the mask,

2. The alignment device of claim 1,

the position acquisition mechanism acquires the relative position before placement using the first imaging unit and the objective lens, and acquires the relative position after placement using the second imaging unit and the objective lens.

3. An alignment device, comprising:

a substrate holding mechanism having a support portion that supports a peripheral portion of a substrate;

a mask holding mechanism that holds a mask;

a position acquisition unit having an imaging unit for imaging a substrate mark provided on the substrate and a mask mark provided on the mask, and configured to acquire a relative positional deviation between the substrate mark and the mask mark imaged by the imaging unit; and

the imaging mechanism includes: a first imaging unit having a first imaging magnification; a second imaging unit having a second imaging magnification larger than the first imaging magnification; and an objective lens commonly used in the first and second image pickup sections,

the position acquisition mechanism acquires the relative position before mounting using the first imaging unit and the objective lens, and acquires the relative position after mounting using the second imaging unit and the objective lens.

4. The alignment device of claim 3,

the substrate is rectangular and the substrate mark is provided at each corner of the rectangle, and the mask is rectangular and the mask mark is provided at each corner of the rectangle.

5. The alignment device according to any one of claims 1 to 4,

the position acquiring unit acquires the relative positional deviation before mounting in a state where the substrate is not in contact with the mask.

6. The alignment device according to any one of claims 1 to 4,

the position adjustment mechanism performs the position adjustment operation by relatively moving the substrate and the mask in a direction parallel to a mounting surface of the substrate in the mask.

7. The alignment device according to any one of claims 1 to 4,

the substrate holding mechanism, after the alignment, relatively moves the substrate and the mask in a direction perpendicular to a surface of the mask on which the substrate is placed from a state in which the substrate and the mask are not in contact with each other to bring the substrate and the mask into a state in which the substrate is overlapped with each other, and removes the support of the support portion to the peripheral portion to bring the substrate into a state in which the substrate is placed on the mask.

8. The alignment device of claim 7,

the substrate holding mechanism has a pressing portion that presses the peripheral edge portion so as to sandwich the peripheral edge portion between the pressing portion and the support portion,

the pressing portion is configured to hold the peripheral edge portion in a state of pressing the peripheral edge portion at least until the substrate is placed on the mask in a state of being overlapped with the mask when the pre-placement relative position is acquired from the position acquisition mechanism.

9. A film forming apparatus is characterized in that,

the film forming apparatus includes:

the alignment device of any one of claims 1 to 8; and

and a film forming mechanism for forming a film on the film formation surface of the substrate through the mask.

10. An alignment method for adjusting a relative position between a rectangular substrate and a rectangular mask on which the substrate is placed,

the alignment method comprises the following steps:

a first acquisition step of acquiring a relative positional displacement amount before placement of a substrate mark provided at each corner of the substrate and a mask mark provided at each corner of the mask, using a first imaging unit having a first imaging magnification in a state where the substrate and the mask are not in contact;

a position adjustment step of adjusting a relative position between the substrate and the mask by controlling at least one of a substrate holding mechanism having a support portion for supporting a peripheral portion of the substrate and a mask holding mechanism for holding the mask, in a state where the substrate and the mask are not in contact with each other;

a mounting step of removing the support of the peripheral portion by the support portion of the substrate holding mechanism from a state in which the substrate and the mask are superimposed on each other, thereby mounting the substrate on the mask; and

and a second acquisition step of acquiring a post-placement relative positional displacement amount of the substrate mark and the mask mark using a second imaging unit having a second imaging magnification larger than the first imaging magnification and an objective lens used in common with the first imaging unit in a state where the substrate and the mask are superimposed on each other.

11. The alignment method according to claim 10,

the peripheral edge portion is held between the support portion and the pressing portion in the first acquiring step, the position adjusting step, and the placing step.

12. A film-forming method characterized in that,

the film forming method includes a step of forming a film on the film formation surface of the substrate aligned by the alignment method according to claim 10 or 11 through the mask.

13. A method of manufacturing an electronic device, characterized in that,

the method of manufacturing an electronic device includes a step of manufacturing an electronic device by forming a film on the film formation surface of the substrate aligned by the alignment method according to claim 10 or 11 through the mask.