KR20210078337A - Alignment system, film-forming apparatus, alignment method, film-forming method, manufacturing method of electronic device and recording medium of computer program - Google Patents

Abstract

An alignment system of the present invention includes: a first camera photographing an alignment mark formed on a substrate or a mask; a second camera photographing the alignment mark, and having resolution different from the first camera; a light source for acquisition of reflected light, radiating light to the alignment mark; a light source for acquisition of transmission light, radiating light to the alignment mark; a light source selection part selecting a light source radiating light to the alignment mark, from among the light source for acquisition of reflected light and the light source for acquisition of transmission light; and a position adjuster adjusting a relative position of the mask and the substrate, based on an image made by photographing the alignment mark, to which the light has been radiated by the light source selected by the light source selection part, through the first or second camera. The light source selection part selects different light sources when acquiring an image of the alignment mark through the first camera and acquiring an image of the alignment mark through the second camera. Therefore, the present invention is capable of improving alignment precision.

Description

Alignment system, film forming apparatus, alignment method, film forming method, electronic device manufacturing method and computer program recording medium }

The present invention relates to an alignment system, a film forming apparatus, an alignment method, a film forming method, a manufacturing method of an electronic device, and a computer program recording medium.

In the manufacture of an organic EL display device (organic EL display), when forming an organic light emitting element (organic EL element; OLED) constituting an organic EL display device, a vapor deposition material evaporated from an evaporation source of the film forming apparatus is applied to a pixel pattern formed thereon. By depositing on the substrate through a mask, an organic material layer or a metal layer is formed.

In the film forming apparatus, in order to increase the film forming precision, the relative position of the substrate and the mask is measured before the film forming process, and if the relative position is out of alignment, the position is adjusted (aligned) by moving the substrate and/or the mask relatively. .

The measurement of the relative position of the substrate and the mask is performed by imaging the alignment marks formed on the substrate and the mask with an alignment camera installed on the upper surface of the outside (atmospheric side) of the vacuum container. Since the inside of the vacuum container is dark, it is used for alignment Imaging is performed while illuminating the alignment mark of the board|substrate and a mask with a light source.

Usually, the light source for alignment is provided in the outer upper surface of a vacuum container similarly to an alignment camera. In this case, the alignment camera receives the reflected light from the substrate and the mask, and acquires an image including the alignment mark. Since the difference in the amount of reflected light between the portion where the alignment mark is formed and the portion around it is small, the contrast is low. It is low, and there is a problem in that it is difficult to acquire a high-resolution image. If the resolution of the image acquired with an alignment camera is not high enough, alignment precision will fall and film-forming precision will fall.

In order to image an alignment mark with high resolution, the method of providing the light source for alignment in the inside of a vacuum container is considered. According to this, since the alignment camera acquires an image using the transmitted light which is irradiated from the light source for alignment provided on the opposite side with respect to the board|substrate and the mask, and has passed through the board|substrate and mask, relatively high-resolution image acquisition is possible. However, if the alignment mark is not located on the path of the transmitted light, since the alignment mark is not reflected in the acquired image, there is a problem that the alignment mark cannot be recognized.

An object of the present invention is to provide an alignment system, a film forming apparatus, an alignment method, a film forming method, an electronic device manufacturing method, and a computer program recording medium capable of improving alignment accuracy.

The alignment system according to the first aspect of the present invention includes a first camera for photographing an alignment mark formed on a substrate or a mask, a second camera for photographing the alignment mark and having a resolution different from that of the first camera, and the alignment A light source for irradiating light to the alignment mark is selected from a light source for obtaining reflected light that irradiates light to the mark, a light source for obtaining transmitted light that irradiates light to the alignment mark, and the light source for obtaining reflected light and light source for obtaining transmitted light based on an image captured by the first camera or the second camera of the alignment mark irradiated with light by the light source selected by the light source selector and the light source selector, the relative position of the substrate and the mask is determined and a positioning mechanism for adjusting, wherein the light source selection unit selects a different light source when acquiring an image of the alignment mark with the first camera and when acquiring an image of the alignment mark with the second camera characterized in that

A film forming apparatus according to a second aspect of the present invention is a film forming apparatus for forming a deposition material on a substrate through a mask, and is characterized by including the alignment system according to the first aspect of the present invention.

An alignment method according to a third aspect of the present invention is an alignment method for adjusting the relative position of a substrate and a mask, and among a light source for obtaining reflected light and a light source for obtaining transmitted light, light is irradiated by any one light source, a substrate or A first relative position of adjusting the relative position of the substrate and the mask based on a first image acquisition step, a first image acquisition step of acquiring a first image by imaging the alignment mark formed on the mask with a first camera, and the first image adjusting step, and capturing the alignment mark irradiated with light by another light source among the reflected light acquisition light source and the transmitted light acquisition light source with a second camera having a resolution different from that of the first camera to obtain a second image and a second relative position adjustment step of adjusting the relative positions of the substrate and the mask based on the second image.

A computer-readable recording medium according to a fourth aspect of the present invention is a computer-readable recording medium storing a program for causing a computer to execute an alignment method for adjusting the relative positions of a substrate and a mask, the alignment method comprising: It is characterized in that it is an alignment method according to the third aspect.

A computer program according to a fifth aspect of the present invention is a computer program stored in a medium for executing an alignment method for adjusting a relative position of a substrate and a mask on a computer, the alignment method comprising: It is characterized in that it is an alignment method.

A film forming method according to a sixth aspect of the present invention is a film forming method for forming a vapor deposition material on a substrate through a mask, and is characterized by including the alignment method according to the third aspect of the present invention.

A method for manufacturing an electronic device according to a seventh aspect of the present invention is characterized in that the electronic device is manufactured using the film forming method according to the sixth aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, alignment precision can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of a part of the manufacturing apparatus of an electronic device.
2 is a schematic diagram of a film forming apparatus according to an embodiment of the present invention.
It is a schematic diagram of the alignment system which concerns on one Embodiment of this invention.
4A and 4B are schematic cross-sectional views of a part of a mask showing the shape of a through hole according to an embodiment of the present invention.
5A and 5B are flowcharts illustrating an alignment method according to an embodiment of the present invention.
It is a schematic diagram which shows an electronic device.

Hereinafter, preferred embodiments and examples of the present invention will be described with reference to the drawings. However, the following embodiments and examples are merely illustrative of preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. In addition, in the following description, the hardware configuration and software configuration of the device, processing flow, manufacturing conditions, size, material, shape, etc. are intended to limit the scope of the present invention to these unless specifically stated otherwise. no.

The present invention can be applied to an apparatus for forming a film by depositing various materials on the surface of a substrate, and can be preferably applied to an apparatus for forming a thin film (material layer) of a desired pattern by vacuum deposition. As the material of the substrate, any material such as glass, a polymer film, metal, or silicon can be selected. For example, the substrate may be a substrate in which a film such as polyimide is laminated on a glass substrate or a silicon wafer. Moreover, arbitrary materials, such as an organic material and a metallic material (metal, metal oxide, etc.), can be selected also as a vapor deposition material. In addition to the vacuum deposition apparatus described in the following description, the present invention can also be applied to a film forming apparatus including a sputtering apparatus or a CVD (Chemical Vapor Deposition) apparatus. The technique of this invention is specifically applicable to manufacturing apparatuses, such as an organic electronic device (For example, organic electroluminescent element, a thin film solar cell), an optical member. Among them, an apparatus for manufacturing an organic EL element that forms an organic EL element by evaporating a vapor deposition material and depositing it on a substrate through a mask is one of preferred application examples of the present invention.

<Electronic device manufacturing apparatus>

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows typically the structure of a part of the manufacturing apparatus of an electronic device.

The manufacturing apparatus of FIG. 1 is used for manufacture of the display panel of an organic electroluminescent display apparatus, for example. In the case of a display panel for VR HMD, after forming a film for forming an organic EL element on a silicon wafer of a predetermined size, the silicon wafer is cut out along the region (scribe region) between the element formation regions to form a plurality of small-sized silicon wafers. made from a panel of In the case of display panels for smartphones, the 4.5th generation substrate (approximately 700 mm × approximately 900 mm), the 6th generation full size (approximately 1500 mm × approximately 1850 mm) or half-cut size (approximately 1500 mm × approximately 925 mm) ) is formed on the substrate for forming an organic EL element, and then the substrate is cut out to produce a plurality of small-sized panels.

An electronic device manufacturing apparatus generally includes a plurality of cluster apparatuses 1 and a relay device connecting between the cluster apparatuses 1 .

The cluster apparatus 1 includes a plurality of film forming apparatuses 11 for performing a process (eg, film formation) on a substrate W, a plurality of mask stock apparatuses 12 for accommodating the masks M before and after use; A transfer chamber 13 disposed in the center thereof is provided. The transfer chamber 13 is connected to each of a plurality of film forming apparatuses 11 and a mask stock apparatus 12 as shown in FIG. 1 .

In the transfer chamber 13 , a transfer robot 14 that transfers a substrate or a mask is disposed. The transport robot 14 transports the substrate W from the pass chamber 15 of the relay device arranged on the upstream side to the film forming device 11 . In addition, the transfer robot 14 transfers the mask M between the film forming apparatus 11 and the mask stock apparatus 12 . The transfer robot 14 may be, for example, a robot having a structure in which a robot hand holding the substrate W or the mask M is mounted on an articulated arm.

In the film-forming apparatus 11 (also called a vapor deposition apparatus), the vapor deposition material accommodated in an evaporation source is heated by a heater, and evaporates, and is vapor-deposited on the board|substrate through a mask. The transfer of the substrate W/mask M with the transfer robot 14, adjustment (alignment) of the relative position of the substrate W and the mask M, and of the substrate W on the mask M A series of film-forming processes such as fixing and film-forming (evaporation) are performed by the film-forming apparatus 11 .

In the mask stock apparatus 12 , a new mask and a used mask to be used in the film forming process in the film forming apparatus 11 are divided and stored in two cassettes. The transfer robot 14 transfers the used mask from the film forming apparatus 11 to the cassette of the mask stock apparatus 12 , and transfers a new mask stored in another cassette of the mask stock apparatus 12 to the film forming apparatus 11 . return to

The cluster device 1 has a path chamber 15 for transferring the substrate W from the upstream side in the flow direction of the substrate W to the cluster device 1 , and the cluster device 1 has a film forming process completed. A buffer chamber 16 for transferring the substrate W to another cluster device on the downstream side is connected. The transfer robot 14 in the transfer chamber 13 receives the substrate W from the pass chamber 15 on the upstream side, and receives one of the film forming apparatuses 11 in the cluster apparatus 1 (eg, the film forming apparatus 11a). ) is returned to In addition, the transfer robot 14 receives the substrate W on which the film forming process in the cluster apparatus 1 has been completed from one of the plurality of film forming apparatuses 11 (eg, the film forming apparatus 11b), and is connected to the downstream side. It is transferred to the buffer chamber 16 .

Between the buffer chamber 16 and the pass chamber 15, a turning chamber 17 for changing the direction of the substrate may be provided. In the turning chamber 17 , a transfer robot 18 for receiving the substrate W from the buffer chamber 16 , rotating the substrate W by 180 degrees, and transferring the substrate W to the pass chamber 15 is installed. Through this, the orientation of the substrate W is the same in the upstream cluster device and the downstream cluster device, thereby facilitating substrate processing.

The pass chamber 15, the buffer chamber 16, and the vortex chamber 17 are so-called relay devices connecting the cluster devices. The relay devices installed on the upstream and/or downstream side of the cluster device include the pass chamber and the buffer chamber. , including at least one of the turning rooms.

The film forming apparatus 11 , the mask stock apparatus 12 , the transfer chamber 13 , the buffer chamber 16 , the swirl chamber 17 and the like are maintained in a high vacuum state during the manufacturing process of the organic light emitting device. The pass chamber 15 is normally maintained in a low vacuum state, but may be maintained in a high vacuum state if necessary.

In the present embodiment, the configuration of the electronic device manufacturing apparatus has been described with reference to FIG. 1 , but the present invention is not limited thereto, and other types of apparatuses or chambers may be provided, and arrangements between these apparatuses or chambers may vary. have. For example, in the present invention, after aligning and bonding the substrate W and the mask M not in the film forming apparatus 11 but in a separate apparatus or chamber, they are mounted on a carrier and transported through the film forming apparatus arranged in a line. It can also be applied to an in-line-type manufacturing apparatus that performs a film forming process while making the film.

Hereinafter, the specific structure of the film-forming apparatus 11 is demonstrated.

<Film forming device>

2 is a schematic diagram showing the configuration of the film forming apparatus 11 . In the following description, directions perpendicular to each other on a plane (XY plane) parallel to the film formation surface of the substrate W are defined as the X direction (first direction) and Y direction (second direction), and the substrate W ), an XYZ orthogonal coordinate system in which the vertical direction perpendicular to the film-forming surface is the Z direction (third direction) is used. In addition, the rotation angle (rotation direction) around the Z axis is expressed as θ.

The film forming apparatus 11 includes a vacuum container 21 maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen gas, a substrate support unit 22 installed in the vacuum container 21 , and a mask support unit 23 , , an electrostatic chuck 24 , and an evaporation source 25 .

The substrate holding unit 22 is a means for receiving and holding the substrate W transferred by the transfer robot 14 installed in the transfer chamber 13 , and is also called a substrate holder.

The mask holding unit 23 is a means for receiving and holding the mask M transported by the transport robot 14 installed in the transport chamber 13 , and is also called a mask holder.

The mask M supported by the mask support unit 23 contains a mask foil and a mask frame. An opening pattern corresponding to the thin film pattern to be formed on the substrate W is formed on the mask foil, and an alignment mark of a predetermined shape is formed on the outer periphery where the opening pattern is not formed. And the mask frame is a member to which the outer periphery of mask foil is fixed. It is preferable that the material of mask foil has transparency with respect to visible light or near-infrared light, such as silicon and glass. On the other hand, the material of the mask frame is not particularly limited, and may be formed of a material that does not transmit light.

An electrostatic chuck 24 serving as a substrate adsorption means for adsorbing and fixing the substrate W is installed above the substrate support unit 22 .

The electrostatic chuck 24 may be an electrostatic chuck of a Coulomb force type in which a relatively high-resistance dielectric is interposed between the electrode and the adsorption surface and adsorption is performed by the Coulomb force between the electrode and the adsorbed body, or between the electrode and the adsorption surface. An electrostatic chuck of a Johnson-Rahbek force type in which a dielectric with relatively low resistance is interposed and adsorption is performed by Johnson-Rabeck force generated between the adsorption surface of the dielectric and an adsorbed body. type electrostatic chuck.

When the adsorbed body is a conductor or a semiconductor (silicon wafer), it is preferable to use a Coulomb force type electrostatic chuck or a Johnson-Rabeck force type electrostatic chuck, and when the adsorbent is an insulator such as glass, a gradient force type electrostatic chuck It is preferable to use a chuck.

The electrostatic chuck 24 may be formed as a single plate, or may be formed to have a plurality of sub-plates capable of independently controlling the adsorption force. In addition, even when a single plate is formed, a plurality of electrode parts may be included therein so that the adsorption force can be independently controlled for each electrode part within one plate.

As the substrate adsorption means, in addition to the electrostatic chuck by electrostatic attraction, an adhesive chuck by adhesive force may be used.

In one embodiment of the film forming apparatus 11 , the cooling plate 30 for suppressing the temperature rise of the substrate W is provided on the opposite side to the suction surface of the electrostatic chuck 24 , so that the deposited on the substrate W is deposited. It is good also as a structure which suppresses the alteration and deterioration of an organic material.

The evaporation source 25 is a crucible (not shown) in which the deposition material to be formed on the substrate is accommodated, a heater (not shown) for heating the crucible, and the evaporation material from scattering to the substrate until the evaporation rate from the evaporation source becomes constant. and a shutter (not shown). The evaporation source 25 may have various configurations depending on the use, such as a point evaporation source, a linear evaporation source, a surface evaporation source, and the like.

Although not shown in FIG. 2, the film forming apparatus 11 includes a film thickness monitor (not shown) and a film thickness calculation unit (not shown) for measuring the film thickness deposited on the substrate.

A substrate support unit actuator 26 , a mask support unit actuator 27 , an electrostatic chuck actuator 28 , a positioning mechanism 29 , and the like are provided on the upper outer side (atmospheric side) of the vacuum vessel 21 . These actuators and the positioning mechanism are constituted by, for example, a motor and a ball screw, or a motor and a linear guide. The substrate supporting unit actuator 26 is a driving means for lifting (moving in the Z direction) the substrate supporting unit 22 . The mask support unit actuator 27 is a driving means for raising/lowering the mask support unit 23 (moving in the Z direction). The electrostatic chuck actuator 28 is a driving means for lifting (moving in the Z direction) the electrostatic chuck 24 .

The positioning mechanism 29 is a means for adjusting the relative position of the substrate W and the mask M, and is an alignment stage mechanism. For example, in the embodiment shown in FIG. 2 , the positioning mechanism 29 moves the electrostatic chuck 24 or the electrostatic chuck actuator 28 as a whole with respect to the substrate support unit 22 and the mask support unit 23 in XYθ. It moves and/or rotates in a direction (at least one of the X direction, the Y direction, and the rotation direction). In the present embodiment, alignment is performed to adjust the relative positions of the substrate W and the mask M by positioning the electrostatic chuck 24 in the XYθ direction while the substrate W is adsorbed. However, the present invention is not limited to this configuration, and for example, the positioning mechanism 29 is not the electrostatic chuck 24 or the electrostatic chuck actuator 28 , but the substrate support unit 22 or the substrate support unit actuator 26 . ) and the mask support unit 23 or the mask support unit actuator 27 may have a configuration capable of relatively moving in the XYθ direction with respect to the electrostatic chuck 24 .

On the outer upper surface of the vacuum container 21, in addition to the driving mechanism and the positioning mechanism described above, the substrate W and the mask M through the transparent window 21a installed on the upper surface of the vacuum container 21 (see FIG. 3). An alignment camera 31 for photographing the formed alignment mark is installed. The camera 31 for alignment is provided in the position corresponding to the alignment mark formed in the board|substrate W and the mask M. For example, the alignment camera 31 may be installed in at least two diagonal corners or all four corners among the four corners forming a rectangle in the circular board|substrate W. As shown in FIG.

According to one embodiment of the film forming apparatus 11, the alignment camera 31 installed in the film forming apparatus 11 is for fine alignment used to adjust the relative position of the substrate W and the mask M with high precision. It is a camera, and although its viewing angle is narrow, it is a camera with high resolution (it has an optical system with high lens magnification). In addition to the fine alignment camera 31 , the film forming apparatus 11 may include a rough alignment camera having a relatively wide viewing angle and low resolution (having an optical system with a low lens magnification). In the configuration in which the alignment camera 31 includes both the fine alignment camera and the rough alignment camera, for example, the rough alignment camera is provided with two cameras at two diagonal corners of a rectangle, fine alignment The camera is installed in the remaining two corners.

According to the embodiment of the present invention, although not shown in Fig. 2, the film forming apparatus 11 includes light source units 102a, 102b for irradiating light to the alignment marks while the alignment marks are photographed by the alignment camera 31, 3) is further included. This is for obtaining a clearer image by illuminating the alignment mark with a light source because the inside of the vacuum container 21 to be sealed is dark in the course of the film forming process.

According to one embodiment of the present invention, the light source unit is provided on the outer upper side of the vacuum container 21 and irradiates light to the alignment mark from below with the light source 102a for obtaining reflected light that irradiates the alignment mark with light from above. and a light source 102b for acquiring transmitted light installed inside the vacuum container 21 . In this case, the alignment camera 31 receives the reflected light from the alignment mark irradiated with light by the reflected light acquisition light source 102a, or transmitted light of the alignment mark irradiated with light by the transmitted light acquisition light source 102b. , and an image including alignment marks is acquired. The specific process of imaging the alignment mark with the alignment camera 31 while selectively irradiating light with the light source for reflected light acquisition 102a or the light source for transmitted light acquisition 102b will be described in detail later.

The film forming apparatus 11 includes a control unit 33 . The control part has functions, such as conveyance and alignment of the board|substrate W/mask M, control of the evaporation source 25, and control of film formation. In particular, the control unit 33 according to the present embodiment may perform a function such as selection of a light source for irradiating light on the alignment mark when acquiring an image including the alignment mark during the alignment step, which will be described later. It will be described in detail.

The control unit 33 is configurable by, for example, a computer having a processor, memory, storage, I/O, and the like. In this case, the function of the control unit 33 is realized by the processor executing the program stored in the memory or storage. As the computer, a general-purpose personal computer may be used, and an embedded computer or a programmable logic controller (PLC) may be used. Alternatively, some or all of the functions of the control unit 33 may be constituted by circuits such as ASICs or FPGAs. In addition, the control part 33 may be provided for each film-forming apparatus, and you may comprise that one control part 33 controls a some film-forming apparatus.

<Alignment system>

3 is a schematic diagram showing the configuration of an alignment system according to an embodiment of the present invention.

Referring to FIG. 3 , the alignment system 100 of the present embodiment includes a camera unit 101 including a first camera and a second camera, a light source for reflected light acquisition 102a and a light source for acquiring transmitted light 102b. It includes light source parts (102a, 102b) and a positioning mechanism (103). And, the alignment system 100 further includes a light source selection unit 104 for selecting a light source for irradiating light to the alignment mark from among the light source for reflected light acquisition 102a and the light source for transmitted light acquisition 102b.

The alignment system 100 performs a relative position adjustment of the substrate W and the mask M before performing a film forming process of depositing a film forming material on the substrate W carried into the film forming apparatus 11 . is a device for Adjustment of the relative position of the board|substrate W and the mask M is based on the image of the alignment mark image|photographed with the 1st camera (camera for rough alignment), The board|substrate W and the mask M relative position are roughly calculated. Based on the rough alignment (1st alignment) process to adjust and the image of the alignment mark image|photographed with the 2nd camera (camera for fine alignment), fine adjusting the relative position of the board|substrate W and the mask M with high precision. An alignment (second alignment) process is included.

The alignment system 100 of this embodiment acquires an image in each of a rough alignment (1st alignment) process and a fine alignment (2nd alignment) process, WHEREIN: The position where the alignment mark was formed and the characteristic of the image requested|required by the said process In consideration of this, a different light source is used. That is, among the light source for reflected light acquisition 102a and the light source for transmitted light acquisition 102b, the light source used in the rough alignment process and the light source used in the fine alignment process are different.

In the image acquired for the alignment process of the substrate W and the mask M, both the alignment marks of the substrate W and the mask M must be reflected in the image, and in order to increase the accuracy of alignment, the contrast of the alignment marks The bigger the better. By the way, even if alignment marks are formed on the substrate W and the mask M (more precisely, the mask foil Ma (refer to FIG. 4A or FIG. 4B)) which transmit the light (visible light or near-infrared light) from the light source, the alignment Since the difference between the amount of reflected light from the mark and the amount of reflected light from the portion of the substrate W where the alignment mark is not formed is small, there is a problem in that it is difficult to obtain an image of low contrast and high contrast.

As one method of acquiring a higher contrast image, there is a method of using transmitted light of an alignment mark. When the substrate W or the mask M has transmittance to the light (visible light or near-infrared light) from the light source, the transmitted light becomes bright in the area without the alignment mark and dark in the area with the alignment mark, and the contrast is reliable Thus, an image with high contrast can be obtained, and an image with a higher resolution can be obtained. However, in order to acquire an image using transmitted light, a light path (optical path) from the transmitted light acquisition light source 102b to the camera unit 101 must be secured, and the substrate W and the mask M on the optical path The alignment mark of should be located.

By the way, the alignment mark of the mask M is formed in the outer peripheral part of mask foil fixed to the mask frame. Therefore, in this embodiment, the through hole H through which the light from the light source 102b for transmitted light acquisition can pass is formed in the mask frame. It is preferable that the position of the through-hole H is a position corresponding to the position in which the alignment mark of the mask M is formed in the outer peripheral part of mask foil Ma.

4A and 4B are cross-sectional views schematically showing the position and shape of the through hole H formed in the mask frame Mb, respectively, according to an embodiment of the present invention.

Referring to FIG. 4A , the outer periphery of the mask foil Ma is fixed to the upper surface of the mask frame Mb. And the through hole H is formed inclined with respect to the normal line direction of the mask foil Ma. According to this, the light irradiated obliquely along the through hole H by the light source 102b for transmitted light acquisition can illuminate the outer peripheral part of the mask foil Ma in which the alignment mark is formed. In addition, it is possible to suppress deposition of the deposition material scattered from the evaporation source 25 toward the substrate W or the mask M in the through hole H during the film forming process. In addition, since the light source for transmitted light acquisition 102b may be disposed outside the scattering path of the deposition material toward the substrate W or the mask M, the deposition material is unnecessary to be deposited on the light source 102b for acquiring the transmitted light. can be reduced

Referring to Figure 4b, the outer periphery of the mask foil (Ma) is fixed to the upper surface of the mask frame (Mb). And the through hole H is formed in parallel to the normal line direction of the mask foil Ma. According to this, the light irradiated in the perpendicular direction along the through hole H by the light source 102b for transmitted light acquisition can illuminate the outer periphery of the mask foil Ma in which the alignment mark is formed. And since it is hard to produce the shadow of an alignment mark compared with embodiment shown in FIG. 4A, a higher contrast image can be acquired.

However, in a configuration in which the transmitted light from the transmitted light acquisition light source 102b is used to acquire an image having a higher contrast, there is a possibility that the alignment mark of the substrate W cannot be recognized. That is, as shown in FIG. 4A or FIG. 4B , the through hole H formed in the mask frame Mb becomes the optical path of the transmitted light. If the alignment mark of the substrate W is located in the area of the through hole H, If not positioned, the alignment mark of the substrate W is not reflected in the image acquired by the camera unit 101, and the alignment mark may not be accurately recognized.

Therefore, according to the embodiment of the present invention, when acquiring an image for rough alignment with the first camera, the alignment mark is irradiated with the light source for reflected light acquisition 102a, and the image of the alignment mark is obtained using the reflected light from the alignment mark. acquire

According to this, even if the alignment mark of the substrate W is not located in the region of the through hole H, an image including the alignment mark of the mask M as well as the alignment mark of the substrate W can be acquired. have.

On the other hand, when an image for fine alignment is acquired by the second camera, the alignment mark is illuminated through the through hole H with the light source for transmitted light acquisition 102b, and the image of the alignment mark is obtained using transmitted light from the alignment mark. to acquire According to this, since an image with a relatively high contrast can be acquired, the precision of alignment can be improved.

The camera unit 101 of the alignment system 100 is for photographing the alignment mark of the substrate W and/or the mask M, and acquiring an image including this, and a first camera which is a camera for rough alignment; , and a second camera that is a camera for fine alignment. The camera unit 101 takes an image including the alignment mark through the transparent window 21a provided on the wall of the vacuum container 21 . For example, the camera unit 101 is provided to face the transparent window 21a by a predetermined mount member provided on the outer wall of the vacuum container 21 .

The camera part 101 may be provided so that it can move with respect to the alignment mark of the board|substrate W or the mask M. For example, as shown in FIG. 3 , the camera unit 101 is installed on the upper outer wall of the vacuum container 21 so as to be movable in the vertical (Z) direction by a mount member having a camera position moving means 105 . may be installed. The camera position moving means 105 is constituted by a servo motor or the like, and is a means for moving the camera unit 101 in the vertical (Z) direction. The camera unit 101 may be installed to be movable not only in the vertical (Z) direction but also in the horizontal (XYθ) direction.

When the camera unit 101 is movably installed, even if the positions of the mask M and/or the substrate W close to each other for alignment are different in the film forming apparatus 11 for each substrate W, , By adjusting the position of the camera unit 101 for each substrate W, the alignment mark can be photographed more clearly. Therefore, alignment precision can be improved.

The light source units 102a and 102b perform a function of illuminating the alignment mark when acquiring an image by photographing the alignment mark with the camera unit 101 . The light source units 102a and 102b may be, but not limited to, lighting means capable of output adjustment that irradiates the alignment marks with light with a predetermined output set under the control of a control means (not shown). For example, the light source units 102a and 102b may be a halogen lamp emitting light including visible light and near-infrared light having a wavelength of 350 nm to 3000 nm or an LED light source emitting light having a wavelength of a predetermined range selected from the range of wavelength 350 nm to 3000 nm. There is (preferably, 1000 nm to 1200 nm).

According to an embodiment of the present invention, the light source units 102a and 102b include a light source 102a for acquiring reflected light and a light source 102b for acquiring transmitted light. The reflected light from the alignment mark irradiated with light by the light source for reflected light acquisition 102a enters the camera unit 101, particularly, the first camera, and an image of the alignment mark is acquired. On the other hand, the transmitted light of the alignment mark irradiated with light by the light source for transmitted light acquisition 102b enters the camera unit 101, particularly, the second camera, and an image of the alignment mark is obtained.

According to one aspect of the present embodiment, the light source 102a for acquiring reflected light is directed in the same direction as the camera unit 101 (in the case of FIG. 3 , the upper side with respect to the mask support unit 23 holding the mask M). direction) is installed. For example, the light source 102a for acquiring reflected light may be installed outside the upper side of the vacuum container 21 . On the other hand, the light source 102b for acquiring transmitted light may be provided in a direction opposite to the camera unit 101 (a downward direction in the case of FIG. 3 ) with respect to the mask support unit 23 . For example, the light source 102b for acquiring transmitted light may be installed below the mask support unit 23 as the inside of the vacuum container 21 .

The light source selection unit 104 performs a function of selecting a light source for irradiating light to the alignment marks when acquiring an image for the alignment process. The light source selection unit 104 may be implemented as an independent functional unit that selects a light source during an alignment operation, or may be implemented as a functional unit of the control unit 33 of the film forming apparatus 11 .

As described above, in the embodiment of the present invention, in the rough alignment (first alignment) step, an image is acquired by imaging with the first camera while illuminating the alignment mark with the reflected light acquisition light source 102a, but fine alignment (Second alignment) At the time of a process, an image is imaged with a 2nd camera, and an image is acquired, illuminating an alignment mark with the light source 102b for transmitted light acquisition. To this end, the light source selection unit 104 selects the light source 102a for acquiring reflected light during the rough alignment process, and selects the light source for acquiring the transmitted light 102b with the light source for illuminating the alignment mark during the fine alignment process performed after the rough alignment. ) is converted to

Referring to FIG. 3 , the positioning mechanism 103 is an alignment stage mechanism for adjusting the relative positions of the substrate W and the mask M, and the positioning mechanism 29 of the film forming apparatus 11 of FIG. 2 . ) corresponds to More specifically, the positioning mechanism 103 uses the image acquired by the camera unit 101 to rotate the substrate W and the mask M in the X direction, the Y direction, and the Z axis in the rotational direction (θ direction). ) is calculated, and then the substrate W and the mask M are relatively moved based on this to adjust the relative positions of the substrate W and the mask M. In particular, the positioning mechanism 103 according to the present embodiment uses an image acquired with the first camera while irradiating the alignment mark with light with the light source 102a for obtaining reflected light at the time of the rough alignment process, but at the time of the fine alignment process The image acquired by the 2nd camera is used for irradiating light to the alignment mark with the light source 102b for transmitted light acquisition.

<Alignment method>

5 is a flowchart illustrating an alignment method according to an embodiment of the present invention. Hereinafter, with reference to FIG. 5, the method of adjusting (aligning) the relative position of the board|substrate W and the mask M is demonstrated.

First, the substrate W is loaded into the film forming apparatus 11 and supported by the substrate support unit 22 . At this time, the mask M, whether previously used in the film forming process for the substrate W, is supported by the mask support unit 23 or is carried into the film forming apparatus 11 prior to the carrying in of the substrate W. and supported by the mask support unit 23 .

Next, after the electrostatic chuck 24 is approached toward the substrate W supported by the substrate support unit 22 (eg, after the electrostatic chuck 24 is lowered toward the substrate W), the electrostatic chuck 24 24), the substrate W is attracted to the electrostatic chuck 24 by electrostatic attraction. Then, by driving the electrostatic chuck actuator 28 and/or the mask support unit actuator 27 , the electrostatic chuck 24 and the mask support unit 23 are relatively brought closer to each other so that the substrate W and the mask M are positioned relative to each other. to be a predetermined measurement position (S1).

Then, using the reflected light, an image including the alignment mark is acquired by the first camera (S2). For example, in a state in which light is irradiated to the alignment mark with the light source 102a for obtaining reflected light, the alignment mark may be imaged with the first camera to obtain an image. In this step, since an image is acquired using reflected light, even if the relative position of the board|substrate W and the mask M shift|deviates greatly, the alignment mark of the board|substrate W and the mask M appears in an image. Alternatively, rough alignment may be performed by aligning the substrate W and the electrostatic chuck using only the alignment marks of the substrate W.

And based on the image acquired in step S2, rough alignment which primarily adjusts the position of the board|substrate W and the mask M is performed (S3). In the case of rough alignment, the position of each of the board|substrate W and the mask M is roughly adjusted so that all the alignment marks of the board|substrate W and the mask M may come in within the viewing angle range of the camera for fine alignment. And according to this embodiment, by a rough alignment process, the alignment mark of the board|substrate W can be made to lie in the area|region of the through hole H formed in the mask frame Mb of the mask M.

Then, when rough alignment is completed, the image in which the alignment mark was acquired with the 2nd camera is acquired using transmitted light (S4). For example, in a state in which light is irradiated to the alignment mark by the light source 102b for acquiring transmitted light, the alignment mark may be imaged by a second camera having a higher resolution than the first camera to obtain an image. In this step, since the image is acquired using transmitted light in a state where the rough alignment process is completed, not only the alignment mark of the mask M but also the alignment mark of the substrate W are captured in the acquired image, and an image with higher contrast It is possible to obtain

And based on the image acquired in step S4, the fine alignment which adjusts the position of the board|substrate W and the mask M secondaryly is performed (S5). More specifically, the control unit 33 measures the relative positions of the substrate W and the mask M in the XYθ direction on the basis of the image acquired in step S4, and then determines the amount of displacement of the relative positions based on this. Calculate. And when the calculated positional shift amount is more than a predetermined threshold value, based on the calculated positional shift amount, the relative position of the board|substrate W and the mask M in XY(theta) direction is adjusted. This process is repeated until the displacement amount of the relative positions of the substrate W and the mask M falls within a predetermined threshold. According to this embodiment, since the image which has a higher contrast is used in a fine alignment process, alignment precision can be improved.

<Film forming process>

Hereinafter, the film-forming method employ|adopted the alignment method which concerns on this embodiment is demonstrated.

In a state in which the mask M is supported by the mask holding unit 23 in the vacuum container 21, the substrate (M) is loaded into the vacuum container 21 of the film forming apparatus 11 by the transfer robot 14 of the transfer chamber 13. W) is imported.

The hand of the transport robot 14 that has entered the vacuum container 21 places the substrate W on the support of the substrate support unit 22 .

Then, after the electrostatic chuck 24 descends toward the substrate W and sufficiently approaches or comes into contact with the substrate W, a predetermined voltage is applied to the electrostatic chuck 24 to adsorb the substrate W. Then, in a state where the substrate W is adsorbed to the electrostatic chuck 24 , the substrate W is brought closer to the mask M in order to measure the relative positional shift of the substrate W with respect to the mask M.

When the board|substrate W and the mask M approach to the relative position measurement position, an alignment process advances according to the alignment method which concerns on this embodiment mentioned above. That is, in a state where the substrate W and the mask M approach the relative position measurement position, the rough alignment process is performed based on the image acquired using the reflected light, and then fine alignment is performed based on the image acquired using the transmitted light. carry out the process

According to the alignment method of this embodiment, when the amount of relative positional shift between the substrate W and the mask M becomes smaller than a predetermined threshold, the shutter of the evaporation source 25 is opened and the vapor deposition material is transferred to the substrate ( W) is deposited.

After deposition to a desired thickness, the mask M is removed, and in a state where only the substrate is adsorbed to the electrostatic chuck 24 , the substrate is raised by the electrostatic chuck actuator 28 .

Then, the hand of the transport robot 14 enters the vacuum container 21 of the film forming apparatus 11 , and a voltage of zero (0) or reverse polarity is applied to the electrode part or the sub-electrode part of the electrostatic chuck 24, so that the substrate (W) is separated from the electrostatic chuck (24). The separated substrate is unloaded from the vacuum container 21 by the transfer robot 14 .

In the above description, the film forming apparatus 11 has a so-called bottom-up deposition method (Depo-up) in which the film is formed in a state in which the film forming surface of the substrate W faces downward in the vertical direction, but it is not limited thereto, and the substrate W is not limited thereto. (W) may be arranged in a state in which it stands vertically on the side surface of the vacuum vessel 21, and the film formation may be performed in a state where the film formation surface of the substrate W is parallel to the direction of gravity.

<Method of manufacturing electronic device>

Next, an example of the manufacturing method of the electronic device using the film-forming apparatus of this embodiment is demonstrated. Hereinafter, the structure and manufacturing method of an organic electroluminescent display are illustrated as an example of an electronic device.

First, an organic EL display device to be manufactured will be described. Fig. 6(a) is an overall view of the organic EL display device 60, and Fig. 6(b) shows a cross-sectional structure of one pixel.

As shown in FIG. 6A , in the display area 61 of the organic EL display device 60, a plurality of pixels 62 including a plurality of light emitting elements are arranged in a matrix form. Although details will be described later, each of the light emitting devices has a structure including an organic layer sandwiched between a pair of electrodes. In addition, the pixel here refers to the minimum unit which enables the display of a desired color in the display area 61. As shown in FIG. In the case of the organic EL display device according to the present embodiment, the pixel 62 is constituted by a combination of the first light emitting element 62R, the second light emitting element 62G, and the third light emitting element 62B that emit light different from each other. has been The pixel 62 is often composed of a combination of a red light emitting device, a green light emitting device, and a blue light emitting device, but may be a combination of a yellow light emitting device, a cyan light emitting device, and a white light emitting device. no.

Fig. 6(b) is a schematic partial cross-sectional view taken along line AB of Fig. 6(a). The pixel 62 has an organic EL device having an anode 64 , a hole transport layer 65 , light emitting layers 66R, 66G, and 66B, an electron transport layer 67 , and a cathode 68 on a substrate 63 . . Among them, the hole transport layer 65, the light emitting layers 66R, 66G, and 66B, and the electron transport layer 67 correspond to the organic layer. In this embodiment, the light emitting layer 66R is an organic EL layer emitting red light, the light emitting layer 66G is an organic EL layer emitting green color, and the light emitting layer 66B is an organic EL layer emitting blue color. The light-emitting layers 66R, 66G, and 66B are formed in patterns corresponding to light-emitting elements (sometimes referred to as organic EL elements) emitting red, green, and blue, respectively. In addition, the anode 64 is formed separately for each light emitting element. The hole transport layer 65, the electron transport layer 67, and the cathode 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 addition, in order to prevent the anode 64 and the cathode 68 from being short-circuited by foreign substances, an insulating layer 69 is provided between the anodes 64 . In addition, since the organic EL layer is deteriorated by moisture and oxygen, a protective layer 70 for protecting the organic EL element from moisture and oxygen is provided.

Although the hole transport layer 65 and the electron transport layer 67 are shown as one layer in FIG. 6(b), depending on the structure of the organic EL display device, it may be formed of a plurality of layers including the hole blocking layer or the electron blocking layer. may be Also, between the anode 64 and the hole transport layer 65, a hole injection layer having an energy band structure capable of smoothly injecting holes from the anode 64 to the hole transport layer 65 may be formed. . Similarly, an electron injection layer may be formed between the cathode 68 and the electron transport layer 67 .

Next, an example of a manufacturing method of the organic EL display device will be specifically described.

First, a substrate 63 on which a circuit (not shown) for driving an organic EL display device and an anode 64 are formed is prepared.

An acrylic resin is formed by spin coating on the substrate 63 on which the anode 64 is formed, and the acrylic resin is patterned to form an opening in the portion where the anode 64 is formed by lithography to form the insulating layer 69 . This opening corresponds to the light emitting region in which the light emitting element actually emits light.

The substrate 63 patterned with the insulating layer 69 is loaded into the first organic material film forming apparatus, the substrate is held by an electrostatic chuck, and a hole transport layer 65 is formed as a common layer over the anode 64 of the display area. . The hole transport layer 65 is formed by vacuum deposition. In reality, since the hole transport layer 65 is formed in a size larger than that of the display area 61, a high-precision mask is not required.

Next, the substrate 63 formed up to the hole transport layer 65 is loaded into the second organic material film forming apparatus, and is held by an electrostatic chuck. After alignment of the substrate and the mask is performed, and the mask is adsorbed to the electrostatic chuck 24 with the substrate interposed therebetween, a red light emitting layer 66R is formed on the portion of the substrate 63 where a red emitting element is disposed.

Similar to the film formation of the light emitting layer 66R, the light emitting layer 66G emitting green light is formed by the third organic material film forming apparatus, and the light emitting layer 66B which emits blue color is further formed by the fourth organic material film forming apparatus. After the formation of the light emitting layers 66R, 66G, and 66B is completed, an electron transporting layer 67 is formed over the entire display area 61 by the fifth organic material film forming apparatus. The electron transport layer 67 is formed as a layer common to the light emitting layers 66R, 66G, and 66B of the three colors.

A cathode 68 is formed by moving the substrate formed up to the electron transport layer 67 to a metallic deposition material film forming apparatus.

According to the present invention, in the rough alignment process, an image of the alignment mark is acquired with a camera for rough alignment while the alignment mark is illuminated by a light source for obtaining reflected light, and the relative position of the substrate W and the mask M is adjusted. And in a fine alignment process, the image of the alignment mark is acquired with the camera for fine alignment, illuminating the alignment mark with the light source for transmitted light acquisition, and the relative position of the board|substrate W and the mask M is adjusted. Thereby, the precision of an alignment process can be improved.

After that, it is transferred to a plasma CVD apparatus to form a protective layer 70 , thereby completing the organic EL display apparatus 60 .

From the time the substrate 63 on which the insulating layer 69 is patterned is brought into the film forming apparatus until the film formation of the protective layer 70 is completed, when exposed to an atmosphere containing a lot of moisture or oxygen, the electrode is oxidized or organic There is a fear that the light emitting layer made of the EL material is deteriorated by moisture or oxygen. Therefore, in this example, carrying in and carrying out of the board|substrate between film-forming apparatuses are performed in a vacuum atmosphere or inert gas atmosphere.

The above embodiment shows an example of the present invention, and the present invention is not limited to the configuration of the above embodiment, and may be appropriately modified within the scope of the technical idea.

22: substrate support unit
23: mask support unit
24: electrostatic chuck
29: positioning mechanism
31: camera for alignment
33: control unit
101: camera unit
102a: light source for acquiring reflected light
102b: light source for acquiring transmitted light
103: positioning mechanism
104: light source selection unit

Claims (12)

A first camera for photographing the alignment marks formed on the substrate or mask;
a second camera for photographing the alignment mark and having a resolution different from that of the first camera;
a light source for obtaining reflected light that irradiates light to the alignment mark;
a light source for acquiring transmitted light that irradiates the alignment mark with light;
a light source selection unit for selecting a light source for irradiating light to the alignment mark from among the light source for obtaining reflected light and light source for obtaining transmitted light;
a positioning mechanism for adjusting the relative positions of the substrate and the mask based on an image captured by the first camera or the second camera of the alignment mark irradiated with light by the light source selected by the light source selection unit;
including,
The said light source selection part selects a different light source, when acquiring the image of the said alignment mark with the said 1st camera, and when acquiring the image of the said alignment mark with the said 2nd camera, the alignment system characterized by the above-mentioned.
According to claim 1,
The second camera has a higher resolution than the first camera,
The light source selection unit selects the reflected light acquisition light source when acquiring an image of the alignment mark with the first camera, and when acquiring an image of the alignment mark with the second camera, the transmitted light acquisition An alignment system characterized in that the light source is selected.
3. The method of claim 2,
Further comprising a mask support unit for supporting the mask,
The light source for acquiring reflected light is positioned on the same side as the first camera with respect to the mask support unit, and the light source for acquiring transmitted light is positioned on the opposite side to the second camera with respect to the mask support unit. alignment system.
4. The method of claim 3,
The mask includes a mask foil having a predetermined opening pattern formed thereon, and a mask frame for fixing the outer peripheral surface of the mask foil,
The light source for acquiring the transmitted light is an alignment system, characterized in that for irradiating light to the alignment mark through a through hole formed in the mask frame.
5. The method of claim 4,
The through hole is an alignment system, characterized in that formed inclined with respect to the normal direction of the mask thin film.
A film forming apparatus for forming a vapor deposition material on a substrate through a mask, comprising the alignment system according to any one of claims 1 to 5.
An alignment method for adjusting the relative position of a substrate and a mask, comprising:
A first image acquisition step of acquiring a first image by imaging an alignment mark formed on a substrate or mask, irradiated with light by any one of the light source for reflected light acquisition and the light source for transmitted light acquisition, with a first camera, and ,
a first relative position adjustment step of adjusting the relative positions of the substrate and the mask based on the first image;
A second image is acquired by imaging the alignment mark irradiated with light by another light source among the reflected light acquisition light source and the transmitted light acquisition light source with a second camera having a resolution different from that of the first camera 2 image acquisition step;
and a second relative position adjustment step of adjusting the relative positions of the substrate and the mask based on the second image.
8. The method of claim 7,
In the first image acquisition step, an alignment mark irradiated with light by the light source for acquiring reflected light is imaged by the first camera,
In the second image acquisition step, the alignment method characterized in that the image of the alignment mark irradiated by the light source for the transmitted light acquisition with a second camera having a higher resolution than the first camera.
A computer-readable recording medium storing a program for executing an alignment method for adjusting the relative positions of a substrate and a mask on a computer, comprising:
The alignment method is a computer-readable recording medium, characterized in that the alignment method according to claim 7 or 8.
A computer program stored in a medium for executing an alignment method for adjusting a relative position of a substrate and a mask on a computer, comprising:
The alignment method is a computer program stored in a medium, characterized in that the alignment method according to claim 7 or 8.
A film forming method for forming a deposition material on a substrate through a mask, comprising:
A film-forming method comprising the alignment method according to claim 7 or 8.
A method of manufacturing an electronic device, comprising manufacturing the electronic device using the film forming method of claim 11 .

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