Electrostatic chuck system, film formation device, clamping method, film formation method, and electronic device production method

Abstract

An electrostatic chuck system according to the present invention is characterized by comprising: an electrostatic chuck that is for clamping an object to be clamped and that is provided with at least one cutout portion which penetrates through the object to be clamped from a clamping surface for clamping to a surface on the opposite side; an image capture means that can capture, through the cutout portion, an image of the object to be clamped; and a determination means that, on the basis of the image of the object to be clamped which has been captured by the image capture means, determines the degree of clamping of the object to be clamped with the electrostatic chuck.

Description

Electrostatic chuck system, film formation apparatus, adsorption method, film formation method, and electronic device manufacturing method

[0001] The present invention relates to an electrostatic chuck system, a film forming apparatus, a chucking method, a film forming method, and a method for manufacturing an electronic device.

[0002] In the manufacture of an organic EL display device (organic EL display), when forming organic light-emitting elements (organic EL elements; OLEDs) that constitute the organic EL display device, an evaporation material evaporated from an evaporation source of a film-forming device is evaporated onto a substrate through a mask on which a pixel pattern is formed, thereby forming an organic layer and a metal layer.

[0003] In a deposition apparatus using the top-down evaporation method (deposit-up), the evaporation source is installed at the bottom of the vacuum chamber of the deposition apparatus, and the substrate is placed at the top of the vacuum chamber, and evaporation is performed on the bottom surface of the substrate. In the vacuum chamber of such a deposition apparatus using the top-down evaporation method, only the peripheral portion of the bottom surface of the substrate is held by the substrate holder, so the substrate bends due to its own weight, which is one factor that reduces the deposition accuracy. In deposition apparatuses using methods other than the top-down evaporation method, bending due to the substrate's own weight can also occur.

[0004] One method for reducing deflection of the substrate due to its own weight is to electrostatically chuck the entire upper surface of the substrate, thereby reducing deflection of the substrate. Patent Document 1 describes a technology in which, in an electrostatic chuck system that attracts a substrate and a mask with an electrostatic chuck, the electrostatic chuck is provided with alignment notches for photographing alignment marks on the substrate or mask and notches for determining the degree of attraction between the substrate and the electrostatic chuck, and the alignment and the degree of attraction are determined by photographing with a camera through the notches.

[0005] Japanese Patent Application Laid-Open No. 2020-070488

[0006] In the technology of Patent Document 1, the electrostatic chuck is provided with separate notches for alignment and for determining the degree of attraction, but from the viewpoint of suppressing a decrease in the attracting force, it is preferable to provide fewer notches in the electrostatic chuck. Furthermore, Patent Document 1 does not disclose a specific method for determining the degree of attraction.

[0007] The present invention provides an electrostatic chuck system that can determine the degree of attraction between the electrostatic chuck and an object to be attracted by photographing the object to be attracted through a notch provided in the electrostatic chuck.

[0008] The present invention provides an electrostatic chuck system for attracting an object to be attracted, the electrostatic chuck having at least one cutout portion extending from an attracting surface that attracts the object to an opposite surface; an imaging means that can photograph the object to be attracted through the cutout portion; and a determination means that determines the degree of attraction between the electrostatic chuck and the object to be attracted based on an image of the object to be attracted photographed by the imaging means.

[0009] According to the present invention, it is possible to provide an electrostatic chuck system that can determine the degree of attraction between the electrostatic chuck and an object to be attracted by photographing the object to be attracted through a cutout portion provided in the electrostatic chuck.

[0010] FIG. 1 is a diagram showing an electronic device manufacturing apparatus according to an embodiment; FIG. 2 is a diagram showing a film forming apparatus according to an embodiment; FIG. 3 is a block diagram of an electrostatic chuck system according to an embodiment, and a cross-sectional view and a plan view of an electrostatic chuck; FIG. 4 is a plan view of an electrostatic chuck according to an embodiment; FIG. 5 is a schematic view of an image obtained by photographing an alignment mark according to an embodiment; FIG. 6 is a flowchart showing the flow of a film forming process according to an embodiment; and FIG. 7 is a diagram showing an electronic device according to an embodiment.

[0011] Preferred embodiments and examples of the present invention will be described below with reference to the drawings. However, the following embodiments and examples merely exemplify preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. Furthermore, unless otherwise specified, the hardware and software configurations, processing flows, manufacturing conditions, dimensions, materials, shapes, etc. of the device in the following description are not intended to limit the scope of the present invention to those alone.

[0012] The present invention can be applied to an apparatus for depositing various materials on the surface of a substrate to form a film, and is preferably applied to an apparatus for forming a thin film (material layer) of a desired pattern by vacuum deposition. The substrate material can be any material, such as glass, a polymeric film, or metal. For example, the substrate may be a glass substrate with a film such as polyimide laminated thereon. Furthermore, the deposition material can be any material, such as an organic material or a metallic material (metal, metal oxide, etc.). In addition to the vacuum deposition apparatus described below, the present invention can also be applied to film formation apparatuses including sputtering apparatuses and CVD (Chemical Vapor Deposition) apparatuses. Specifically, the technology of the present invention can be applied to apparatuses for manufacturing organic electronic devices (e.g., organic EL elements, thin-film solar cells), optical components, etc. Among these, an apparatus for manufacturing organic EL elements, which forms organic EL elements by evaporating a deposition material and depositing it on a substrate through a mask, is one preferred application example of the present invention.

[0013] <Electronic Device Manufacturing Apparatus> FIG. 1 is a plan view schematically showing the configuration of a portion of an electronic device manufacturing apparatus.

[0014] 1 is used to manufacture display panels for organic EL display devices for smartphones, for example. Electronic device manufacturing equipment generally includes a plurality of cluster devices 1 and relay devices connecting the cluster devices 1.

[0015] The cluster apparatus 1 includes a plurality of film forming apparatuses 11 that perform processing (e.g., film formation) on substrates S, a plurality of mask stock apparatuses 12 that store masks M before and after use, and a transfer chamber 13 disposed in the center thereof. As shown in FIG. 1 , the transfer chamber 13 is connected to each of the plurality of film forming apparatuses 11 and the mask stock apparatus 12.

[0016] A transfer robot 14 that transfers the substrate S and the mask M is disposed within the transfer chamber 13. The transfer robot 14 transfers the substrate S from a pass chamber 15 of a relay device disposed upstream to the film formation device 11. The transfer robot 14 also transfers the mask M between the film formation device 11 and the mask stock device 12. The transfer robot 14 is, for example, a robot having a structure in which a robot hand that holds the substrate S or the mask M is attached to an articulated arm.

[0017] In the film forming apparatus 11 (also referred to as a vapor deposition apparatus), a vapor deposition material stored in a vapor deposition source is heated by a heater to evaporate, and is then vapor-deposited onto the substrate S through the mask M. A series of film forming processes, such as transferring the substrate S to or from the transfer robot 14, adjusting the relative positions of the substrate S and the mask M (alignment), fixing the substrate S on the mask M, and film formation (vapor deposition), are performed by the film forming apparatus 11.

[0018] In the mask stock device 12, new masks M to be used in the film formation process in the film formation device 11 and used masks M are stored in two cassettes. The transfer robot 14 transfers the used masks M from the film formation device 11 to a cassette in the mask stock device 12, and transfers the new masks M stored in another cassette in the mask stock device 12 to the film formation device 11.

[0019] The cluster apparatus 1 is connected to a pass chamber 15 that transfers the substrate S from the upstream side in the transfer direction of the substrate S to the cluster apparatus 1, and a buffer chamber 16 that transfers the substrate S, for which film formation processing has been completed in the cluster apparatus 1, to another cluster apparatus on the downstream side. A transfer robot 14 in the transfer chamber 13 receives the substrate S from the upstream pass chamber 15 and transfers it to one of the film formation apparatuses 11 (e.g., film formation apparatus 11a) in the cluster apparatus 1. The transfer robot 14 also receives the substrate S, for which film formation processing has been completed in the cluster apparatus 1, from one of the film formation apparatuses 11 (e.g., film formation apparatus 11b), and transfers it to the buffer chamber 16 connected downstream.

[0020] A swirl chamber 17 that changes the orientation of the substrate S is installed between the buffer chamber 16 and the pass chamber 15. A transfer robot 18 is provided in the swirl chamber 17 to receive the substrate S from the buffer chamber 16, rotate the substrate S by 180°, and transfer it to the pass chamber 15. This ensures that the orientation of the substrate S is the same in the upstream cluster apparatus 1 and the downstream cluster apparatus 1, facilitating substrate processing.

[0021] The pass chamber 15, the buffer chamber 16, and the swirl chamber 17 are so-called relay devices that connect the cluster devices 1, and the relay device installed upstream and / or downstream of the cluster device 1 has at least one of the pass chamber 15, the buffer chamber 16, and the swirl chamber 17.

[0022] The film forming device 11, the mask stock device 12, the transfer chamber 13, the buffer chamber 16, the swirl chamber 17, etc. are maintained in a high vacuum state during the manufacturing process of the organic EL element. The pass chamber 15 is usually maintained in a low vacuum state, but may be maintained in a high vacuum state as necessary.

[0023] The configuration of the electronic device manufacturing apparatus to which the present invention can be applied is not limited to the above configuration, and other types of apparatuses and chambers may be included, and the arrangement of these apparatuses and chambers may be changed. The specific configuration of the film forming apparatus 11 will be described below.

[0024] <Film Forming Apparatus> Figure 2 is a schematic diagram showing the configuration of a film forming apparatus 11. In the following description, an XYZ Cartesian coordinate system is used, with the vertical direction being the Z direction. When the substrate S is fixed so as to be parallel to a horizontal plane (XY plane) during film formation, the short side direction (direction parallel to the short side) of the substrate S is the X direction, and the long side direction (direction parallel to the long side) is the Y direction. The rotation angle around the Z axis is represented by θ.

[0025] The film forming apparatus 11 has a vacuum vessel 21 maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen gas, and a substrate support unit 22, a mask support unit 23, an electrostatic chuck 24, and an evaporation source 25 provided inside the vacuum vessel 21.

[0026] The substrate support unit 22 is a means for receiving and holding the substrate S transported by the transport robot 14 provided in the transport chamber 13, and is also called a substrate holder.

[0027] A mask support unit 23 is provided below the substrate support unit 22. The mask support unit 23 is a means for receiving and holding the mask M transferred by the transfer robot 14 provided in the transfer chamber 13, and is also called a mask holder.

[0028] The mask M has an opening pattern corresponding to the thin film pattern to be formed on the substrate S, and is placed on the mask support unit 23. For example, the mask used to manufacture organic EL elements for smartphones is a metal mask with a fine opening pattern formed therein, and is also called an FMM (Fine Metal Mask).

[0029] An electrostatic chuck 24 is provided above the substrate support unit 22 to attract and fix the substrate S and / or mask M by electrostatic attraction. The electrostatic chuck 24 attracts and holds the substrate S (first attractable object) before film formation. Thereafter, film formation is performed while the substrate S (first attractable object) and the mask M (second attractable object) are held by the electrostatic chuck 24, and after film formation is completed, the holding of the substrate S (first attractable object) and the mask M (second attractable object) by the electrostatic chuck 24 is released.

[0030] The electrostatic chuck 24 has a structure in which an electric circuit such as a metal electrode is embedded in a dielectric (e.g., ceramic) matrix. The electrostatic chuck 24 may be a Coulomb force type electrostatic chuck, a Johnsen-Rahbek force type electrostatic chuck, or a gradient force type electrostatic chuck. The electrostatic chuck 24 is preferably a gradient force type electrostatic chuck. When the electrostatic chuck 24 is a gradient force type electrostatic chuck, even an insulating substrate S can be satisfactorily attracted by the electrostatic chuck 24. When the electrostatic chuck 24 is a Coulomb force type electrostatic chuck, when positive and negative voltages are applied to the metal electrodes, polarized charges of opposite polarity to those of the metal electrodes are induced in an object to be attracted, such as the substrate S, through the dielectric matrix, and the substrate S is attracted and fixed to the electrostatic chuck 24 by the electrostatic attraction therebetween.

[0031] The electrostatic chuck 24 may be formed of a single plate or may be formed to have multiple sub-plates. Even if it is formed of a single plate, it may have multiple electric circuits therein and control the electrostatic attractive force to vary depending on the position within the single plate.

[0032] The electrostatic chuck 24 has one or more through holes H, which are notches, formed to penetrate the plate. One through hole H can serve both as an alignment through hole for enabling an image of an alignment mark formed on the substrate S or the mask M to be captured through the electrostatic chuck 24, and as an attraction degree determination through hole for determining the attraction degree (contact degree) between the electrostatic chuck 24 and the substrate S or the attraction degree between the substrate S and the mask M. Note that the alignment through hole and the attraction degree determination through hole may be provided separately. However, a configuration in which both alignment and attraction degree determination can be performed with one through hole allows the number of holes provided in the electrostatic chuck 24 to be reduced, thereby suppressing a decrease in the attraction force due to the provision of the hole.

[0033] The through holes H are provided, for example, at four diagonal corners and a central portion of the rectangular electrostatic chuck plate. Note that the locations and number of the through holes H are merely examples, and the present invention is not limited to the above example. For example, the through holes H may be provided at two corners instead of the four diagonal corners. Furthermore, an additional through hole H may be provided at the center of a pair of opposing sides (e.g., short sides). The through holes H may be formed by subsequently performing a notch process on a member that does not have a through hole, or may be provided by forming the member so that it has a through hole from the beginning. The shape of the notch may be any shape as long as it penetrates from the attracting surface that attracts the attractable object to the opposite surface and allows the attractable object to be photographed by a camera through the notch.

[0034] Although not shown in FIG. 2 , a cooling mechanism (e.g., a cooling plate) for suppressing a temperature rise of the substrate S may be provided on the side opposite the attracting surface of the electrostatic chuck 24, thereby suppressing alteration or deterioration of the organic material deposited on the substrate S.

[0035] The evaporation source 25 includes a crucible (not shown) for storing an evaporation material to be deposited on the substrate S, a heater (not shown) for heating the crucible, and a shutter (not shown) for preventing the evaporation material from scattering onto the substrate S until the evaporation rate from the evaporation source 25 becomes constant. The evaporation source 25 may have various configurations depending on the application, such as a point evaporation source or a linear evaporation source.

[0036] Although not shown in FIG. 2, the film forming apparatus 11 has a film thickness monitor (not shown) for measuring the thickness of the film deposited on the substrate S, and a film thickness calculation unit (not shown).

[0037] A substrate Z actuator 26, a mask Z actuator 27, an electrostatic chuck Z actuator 28, a position adjustment mechanism 29, and the like are provided on the upper outside (atmosphere side) of the vacuum vessel 21. These actuators 26, 27, 28 and the position adjustment mechanism 29 are composed of, for example, a motor and a ball screw, or a motor and a linear guide. The substrate Z actuator 26 is a driving means for raising and lowering (moving in the Z direction) the substrate support unit 22. The mask Z actuator 27 is a driving means for raising and lowering (moving in the Z direction) the mask support unit 23. The electrostatic chuck Z actuator 28 is a driving means for raising and lowering (moving in the Z direction) the electrostatic chuck 24.

[0038] The position adjustment mechanism 29 is a driving means for aligning the electrostatic chuck 24. The position adjustment mechanism 29 moves the entire electrostatic chuck 24 in the X direction, the Y direction, and rotates it by θ relative to the substrate support unit 22 and the mask support unit 23. Note that by adjusting the position of the electrostatic chuck 24 in the X, Y, and θ directions while the substrate S is attracted, alignment is performed to adjust the relative positions of the substrate S and the mask M.

[0039] In addition to the driving means and position adjustment mechanism described above, cameras 20 are provided on the outer upper surface of the vacuum vessel 21 for photographing alignment marks formed on the substrate S and mask M through transparent windows provided on the upper surface of the vacuum vessel 21 and holes provided in the electrostatic chuck 24. The cameras 20 are provided at positions corresponding to the through holes H provided in the electrostatic chuck 24, i.e., at positions corresponding to the four corners and the center of the electrostatic chuck 24.

[0040] The camera 20 is a camera capable of fine alignment, which adjusts the relative positions of the substrate S and the mask M with high precision, and has a narrow viewing angle but high resolution. Note that the film forming apparatus 11 may have, in addition to the fine alignment camera 20, a rough alignment camera with a relatively wide viewing angle and low resolution, and align the substrate S and the mask M by combining rough alignment using the rough alignment camera and fine alignment using the fine alignment camera.

[0041] The control unit 40 acquires position information of the substrate S (first attractable body) and the mask M (second attractable body) by analyzing images of the alignment marks of the substrate S (first attractable body) and the mask M (second attractable body) captured by the camera 20. The control unit 40 controls the position adjustment mechanism 29 based on the position information of the substrate S and the mask M to perform alignment by moving the substrate S (first attractable body) and the mask M (second attractable body) relative to each other to adjust their positions. The control unit 40 also analyzes the image of the substrate S captured by the camera 20 to determine the degree of attraction between the substrate S and the electrostatic chuck 24. The control unit 40 adjusts the attraction force of the electrostatic chuck 24 as necessary based on the degree of attraction.

[0042] The control unit 40 has functions of transporting and aligning the substrate S, controlling the deposition source 25, controlling film formation, etc. The control unit 40 also has a function of controlling the application of voltage to the electrostatic chuck 24, that is, a function of a voltage control unit 32 in FIG.

[0043] The control unit 40 can be configured, for example, by a computer having a processor, memory, storage, I / O, etc. In this case, the functions of the control unit 40 are realized by the processor executing a program stored in the memory or storage. The computer may be a general-purpose personal computer, an embedded computer, or a PLC (Programmable Logic Controller). Alternatively, some or all of the functions of the control unit 40 may be configured by a circuit such as an ASIC or FPGA. Furthermore, a control unit 40 may be installed for each film forming apparatus 11, or one control unit 40 may be configured to control multiple film forming apparatuses 11.

[0044] <Electrostatic Chuck System and Adsorption Method> The electrostatic chuck system 30 and the adsorption method will be described with reference to Figures 3(a), 3(b), and 4. Figure 3(a) is a block diagram of the electrostatic chuck system 30 and a cross-sectional view of the electrostatic chuck 24, and Figure 3(b) is a plan view of the electrostatic chuck 24. Figure 4 is a plan view for explaining the configuration of the electrostatic chuck 24.

[0045] 3A, the electrostatic chuck system 30 includes the electrostatic chuck 24, a voltage application unit 31, and a voltage control unit 32. The voltage application unit 31 applies a voltage to the sub-electrode units 241 to 249 of the electrostatic chuck 24 to generate an electrostatic attractive force.

[0046] The voltage control unit 32 controls the magnitude of the voltage applied to the electrode unit 240a from the voltage application unit 31, the start time of voltage application, the duration of voltage maintenance, the order of voltage application, etc., depending on the progress of the chucking process of the electrostatic chuck system 30 or the film formation process of the film formation apparatus 11. The voltage control unit 32 can, for example, independently control the voltage application to each of the multiple sub-electrodes 241 to 249 included in the electrode unit 240a of the electrostatic chuck 24. The voltage control unit 32 is configured separately from the control unit 40 of the film formation apparatus 11, but may also be integrated into the control unit 40 of the film formation apparatus 11.

[0047] The electrostatic chuck 24 has an electrostatic chuck plate 240 having a structure in which an electric circuit such as a metal electrode is embedded in a matrix of a dielectric material (e.g., a ceramic material). The electrostatic chuck plate 240 has an electrode portion 240a and a dielectric portion 240b. The electrode portion 240a generates an attraction force for attracting an object to be attracted (e.g., a substrate S or a mask M) to the attraction surface by applying a voltage from the voltage application unit 31. The dielectric portion 240b is formed of one or more dielectric materials and is interposed at least between the electrode portion 240a and the attraction surface. The electrostatic chuck plate 240 has a shape corresponding to the shape of the substrate S, for example, a rectangular shape.

[0048] The electrostatic chuck plate 240 has one or more through holes H, which are notches, formed to penetrate the plate 240 in the vertical direction. No electrode portion is formed in the portion where the through holes H penetrate. The through holes H may be empty spaces that are not filled with anything, or may be filled with a transparent insulating material. As shown in FIG. 4 , the through holes H are provided at the four corner portions and the center of the electrostatic chuck 24. Note that the locations where the through holes H are provided are merely examples, and are set depending on the positions of alignment marks provided on the substrate S and the mask M and the position where the adhesion strength between the substrate S and the electrostatic chuck 24 is to be determined.

[0049] As shown in FIGS. 3A and 3B, the electrode unit 240a has a plurality of sub-electrode portions 241 to 249. Specifically, the electrode unit 240a has a plurality of sub-electrode portions 241 to 249 divided along the longitudinal direction (Y direction) and lateral direction (X direction) of the electrostatic chuck plate unit 240. While FIG. 3B shows an example in which the electrode density of the plurality of sub-electrode portions 241 to 249 is uniform, the electrode density may be set for each sub-electrode portion as necessary. For example, the electrode density may be different between the sub-electrode portion corresponding to the region where the through hole H is provided and the sub-electrode portion corresponding to the region where the through hole H is not provided.

[0050] Each of the sub-electrode portions 241 to 249 has an electrode pair 33 to which a positive (first polarity) and a negative (second polarity) potential are applied in order to generate an electrostatic attraction force. For example, each electrode pair 33 has a first electrode 331 to which a positive potential is applied and a second electrode 332 to which a negative potential is applied.

[0051] As shown in FIG. 3B , the first electrode 331 and the second electrode 332 each have a comb shape. For example, the first electrode 331 and the second electrode 332 each have a plurality of comb-tooth portions and a base portion connected to the plurality of comb-tooth portions. The base portion of each of the first electrode 331 and the second electrode 332 supplies a voltage to the comb-tooth portions, and the plurality of comb-tooth portions generate an electrostatic attraction force between the electrode and the object to be attracted. In one sub-electrode portion, the comb-tooth portions of the first electrode 331 are alternately arranged so as to face the comb-tooth portions of the second electrode 332. By configuring the comb-tooth portions of the first electrode 331 and the second electrode 332 so as to face each other and be intertwined, the spacing between the electrodes to which different voltages are applied can be narrowed, a large non-uniform electric field can be formed, and the substrate S can be attracted by a gradient force. Note that the shapes of the first electrode 331 and the second electrode 332 of each of the sub-electrode portions 241 to 249 of the electrostatic chuck 24 are merely examples and are not limited to the above example. As long as an electrostatic attraction can be generated between the attracting member and the object to be attracted, the attracting member can have various shapes.

[0052] As shown in FIG. 3B , the electrostatic chuck 24 has a plurality of attraction portions 141 to 149 corresponding to a plurality of sub-electrode portions 241 to 249. The attraction portions 141 to 149 are provided so as to be divided in the longitudinal direction (Y-axis direction) and the lateral direction (X-axis direction) of the electrostatic chuck 24. Note that this configuration of the attraction portions is merely an example and is not limited to the above example. For example, the electrostatic chuck 24 may be divided only in the longitudinal direction or the lateral direction. The plurality of attraction portions may be configured such that one physical plate has a plurality of electrode portions, or such that multiple physically divided plates each have one or more electrode portions. Each of the plurality of attraction portions may be configured to correspond to a respective one of the plurality of sub-electrodes, or such that one attraction portion has a plurality of sub-electrodes.

[0053] For example, by controlling the application of voltage to the sub-electrodes 241 to 249 by the voltage control unit 32, three sub-electrodes 241, 244, and 247 arranged in a direction (Y direction) intersecting the adsorption progress direction (X direction) of the substrate S can be made to form a single adsorption unit. That is, although the voltage of each of the three sub-electrodes 241, 244, and 247 can be controlled independently, by controlling the application of the same voltage to these three sub-electrodes 241, 244, and 247 simultaneously, these three electrodes 241, 244, and 247 can function as a single adsorption unit. As long as the substrate can be adsorbed to each of the multiple adsorption units independently, the specific physical structure and electrical circuit structure can be changed.

[0054] <Determination of Alignment and Adsorption Degree> Determination of alignment and adsorption degree based on an image of the substrate S captured by the camera 20 through the through hole H of the electrostatic chuck 24 will be described with reference to Fig. 5. Fig. 5 is a diagram schematically showing images captured by the camera 20. Fig. 5(A) shows an image captured in a state where the adsorption degree between the electrostatic chuck 24 and the substrate S is low and deflection occurs in the substrate S. Fig. 5(B) shows an image captured in a state where the adsorption degree between the electrostatic chuck 24 and the substrate S is high and the substrate S is in sufficient contact with the electrostatic chuck 24 and is not deflected.

[0055] The image 50 captured by the camera 20 shows a through hole H provided in the electrostatic chuck 24, a first substrate mark 51 which is an alignment mark provided on the substrate S, a mask mark 52 which is an alignment mark provided on the mask M positioned below the substrate S, and a second substrate mark 53 which is used to determine the degree of attraction between the substrate S and the electrostatic chuck 24. The control unit 40 acquires the positional relationship between the first substrate mark 51 and the mask mark 52 by analyzing the image 50 captured by the camera 20, and calculates the amount of operation of the position adjustment mechanism 29 required to align the positions of the first substrate mark 51 and the mask mark 52 with the mask mark 52 as a target position. The control unit 40 then drives the position adjustment mechanism 29 in the X direction, Y direction, and θ direction by the calculated amount of operation.

[0056] Furthermore, the control unit 40 detects the second substrate mark 53 by analyzing the image 50 captured by the camera 20, and determines the degree of attraction between the substrate S and the electrostatic chuck 24 based on the detection result of the second substrate mark 53. Here, if the degree of attraction between the substrate S and the electrostatic chuck 24 is low and the substrate S is not in sufficient contact with the electrostatic chuck 24 in a warped state, the second substrate mark 53 will appear as a black image with low brightness in the image 50 captured by the camera 20. On the other hand, if the degree of attraction between the substrate S and the electrostatic chuck 24 is high and the substrate S is in close contact with the electrostatic chuck 24 in an unwarped state, the second substrate mark 53 will appear as a white image with high brightness in the image 50 captured by the camera 20. Therefore, the control unit 40 stores in advance a first model image (sample image) of the second board mark 53 with low brightness, which serves as a reference for determining whether the degree of adhesion of the substrate S is low, and a second model image of the second board mark 53 with high brightness, which serves as a reference for determining whether the degree of adhesion of the substrate S is high, and performs pattern matching on the entire image 50 using the first model image and the second model image based on the pixel arrangement, brightness, etc. Then, when an image is detected that has a higher matching rate with the first model image than with the second model image, it is determined that the degree of adhesion is low, and when an image is detected that has a higher matching rate with the second model image than with the first model image, it is determined that the degree of adhesion is high.

[0057] The method for determining the degree of adhesion is not limited to the above example. For example, pattern matching may be performed only on the shape, and the degree of adhesion may be determined based on the pixel values ​​of the detected pixels constituting the second substrate mark 53. A pixel-value-based determination method may be based on statistical values ​​(sum, average, maximum, minimum, etc.) of the feature quantities (brightness, saturation, chromaticity, etc.) of the pixels constituting the second substrate mark 53. The determination criterion may be determined taking into account the tendency that when the substrate S is in a warped state and not sufficiently adhered to the electrostatic chuck 24, the image of the second substrate mark 53 tends to be darker than when it is in close contact. This is thought to be due to the fact that when the substrate S is not in close contact with the electrostatic chuck 24, the substrate S is tilted with respect to the camera 20, which changes the direction of reflection of light reflected by the substrate S and reduces the amount of light incident on the camera 20. Therefore, for example, if the image of the second substrate mark 53 is close to white, it can be determined that the degree of adhesion is good, and if it is close to black, it can be determined that the degree of adhesion is poor or that peeling has occurred.

[0058] When the control unit 40 determines that the degree of attraction between the substrate S and the electrostatic chuck 24 is low, it adjusts the attraction force of the electrostatic chuck 24. For example, the attraction force is increased by increasing the voltage applied to the electrostatic chuck 24. Alternatively, the attraction may be temporarily released, and the process of attracting the substrate S to the electrostatic chuck 24 may be repeated from the beginning.

[0059] As described above, in this embodiment, alignment and the degree of attraction can be determined based on the image 50 captured by the camera 20 through the through hole H. Therefore, it is not necessary to provide separate holes for alignment and holes for determining the degree of attraction. This reduces the number of through holes H provided in the electrostatic chuck 24. Furthermore, because the degree of attraction can be determined by image analysis, the degree of attraction can be determined using the alignment device without adding a separate device for determining the degree of attraction to the alignment device. While this embodiment has been described with reference to an example in which the first substrate mark 51 for alignment and the second substrate mark 53 for determining the degree of attraction are provided separately, the substrate mark for alignment can also be used as the substrate mark for determining the degree of attraction. In this case, only one type of substrate mark may be used.

[0060] In the above description, an example has been described in which whether the degree of attraction between the substrate S and the electrostatic chuck 24 is good or bad has been determined from a captured image, but it is also possible to determine from a captured image whether the substrate S is attracted to the electrostatic chuck 24 or detached from the electrostatic chuck 24. In this case, a model image serving as a reference for determining whether the substrate S is attracted to the electrostatic chuck 24 and a model image serving as a reference for determining whether the substrate S is detached are determined in advance, and the determination can be made based on pattern matching between the second substrate mark in the captured image and the model image. It is also possible to determine whether the substrate S is attracted to the electrostatic chuck 24 or detached based on feature amounts of the image of the second substrate mark.

[0061] <Film Forming Process> A film forming method employing the adsorption method according to this embodiment will be described below with reference to the flowchart of FIG.

[0062] In step S1, the control unit 40 causes the transfer robot 14 in the transfer chamber 13 to transfer the substrate S into the vacuum vessel 21 of the film forming apparatus 11, with the mask M supported by the mask support unit 23 in the vacuum vessel 21. The hand of the transfer robot 14 that has entered the vacuum vessel 21 is lowered, and the substrate S is placed on the support portion of the substrate support unit 22.

[0063] In step S2, the control unit 40 lowers the electrostatic chuck 24 toward the substrate S, and after it comes sufficiently close to or into contact with the substrate S, applies a predetermined voltage to the electrostatic chuck 24 to attract the substrate S.

[0064] In step S3, the control unit 40 measures the degree of attraction to determine whether the substrate S has been well attracted to the electrostatic chuck 24. The camera 20 photographs the substrate S through the through hole H, and the control unit 40 analyzes the obtained image data to measure the degree of attraction of the substrate S to the electrostatic chuck 24.

[0065] In step S4, the control unit 40 determines whether the degree of attraction of the substrate S to the electrostatic chuck 24 is high. Specifically, as described above, this determination is made based on whether the image of the second substrate mark 53 matches the first model image or the second model image. When the degree of attraction is measured as a pixel value such as brightness or saturation, it is possible to determine whether the degree of attraction is high by comparing the degree of attraction with a predetermined target value. If the degree of attraction is determined to be low, the process proceeds to step S5. If the degree of attraction is determined to be high, the process proceeds to step S6.

[0066] In step S5, the control unit 40 adjusts the attracting force of the electrostatic chuck 24. Specifically, the attracting force is increased by increasing the voltage applied to the electrostatic chuck 24. Thereafter, the attracting strength is determined again in step S4.

[0067] In step S6, the control unit 40 measures the relative positional deviation of the substrate S with respect to the mask M while the substrate S is attracted to the electrostatic chuck 24. The control unit 40 lowers the electrostatic chuck 24, and brings the substrate S attracted to the electrostatic chuck 24 closer to the mask M. When the substrate S has lowered to the measurement position, the control unit 40 photographs the alignment marks formed on the substrate S and the mask M through the through-hole H with the camera 20, and measures the relative positional deviation between the substrate S and the mask M.

[0068] In step S7, the control unit 40 determines whether the relative positional deviation of the substrate S with respect to the mask M is equal to or less than a threshold value. If the positional deviation is greater than the threshold value, the process proceeds to step S8, and if the positional deviation is equal to or less than the threshold value, the process proceeds to step S9.

[0069] In step S8, the control unit 40 controls the position adjustment mechanism 29 to move the substrate S attracted to the electrostatic chuck 24 in the horizontal direction (XYθ directions) to adjust the position (alignment) of the substrate S with respect to the mask M. Thereafter, the positional deviation determination in step S7 is performed again.

[0070] In step S9, the control unit 40 applies a predetermined voltage to the electrode portion or sub-electrode portion of the electrostatic chuck 24 to attract the mask M onto the electrostatic chuck 24 through the substrate S.

[0071] In step S10, the control unit 40 opens the shutter of the deposition source 25 and deposits the deposition material onto the substrate S through the mask M. After the desired thickness has been deposited, the voltage applied to the electrode portion or sub-electrode portion of the electrostatic chuck 24 is reduced to separate the mask M. With only the substrate S attracted to the electrostatic chuck 24, the electrostatic chuck Z actuator 28 raises the electrostatic chuck 24. Next, the hand of the transfer robot 14 enters the vacuum chamber 21 of the film forming apparatus 11, and a voltage of zero (0) or reverse polarity is applied to the electrode portion or sub-electrode portion of the electrostatic chuck 24 to separate the substrate S from the electrostatic chuck 24. Thereafter, the substrate S, for which deposition has been completed, is carried out of the vacuum chamber 21 by the transfer robot 14.

[0072] In the above description, the film forming apparatus 11 is configured as a so-called upward deposition method (depo-up) in which film formation is performed with the film formation surface of the substrate S facing vertically downward, but this is not limited to this, and the film may also be configured in such a way that the substrate S is placed vertically on the side of the vacuum container 21 and film formation is performed with the film formation surface of the substrate S parallel to the direction of gravity.

[0073] <Method for Manufacturing an Electronic Device> Next, an example of a method for manufacturing an electronic device using the film forming apparatus of this embodiment will be described. Hereinafter, the configuration and manufacturing method of an organic EL display device will be illustrated as an example of the electronic device.

[0074] First, the organic EL display device to be manufactured will be described. FIG. 7( a) is an overall view of an organic EL display device 60, and FIG. 7( b) shows the cross-sectional structure of one pixel. As shown in FIG. 7( a), a plurality of pixels 62, each including a plurality of light-emitting elements, are arranged in a matrix in a display area 61 of the organic EL display device 60. As will be described in detail later, each light-emitting element has a structure including an organic layer sandwiched between a pair of electrodes. Note that the term "pixel" here refers to the smallest unit capable of displaying a desired color in the display area 61. In this embodiment, in the case of an organic EL display device, a pixel 62 is configured by a combination of a first light-emitting element 62R, a second light-emitting element 62G, and a third light-emitting element 62B, which emit light different from one another. While the pixel 62 is often configured by a combination of red, green, and blue light-emitting elements, it may also be a combination of yellow, cyan, and white light-emitting elements, and is not particularly limited as long as it emits at least one color.

[0075] 7(b) is a partial cross-sectional schematic diagram taken along line A-B in FIG. 7(a). A pixel 62 includes an organic EL element (EL element) on a substrate 63, the organic EL element including an anode 64, a hole transport layer 65, one of light-emitting layers 66R, 66G, and 66B, an electron transport layer 67, and a cathode 68. Of these, the hole transport layer 65, the light-emitting layers 66R, 66G, and 66B, and the electron transport layer 67 are organic layers. In this embodiment, the light-emitting layer 66R is an organic EL layer that emits red light, the light-emitting layer 66G is an organic EL layer that emits green light, and the light-emitting layer 66B is an organic EL layer that emits blue light. The light-emitting layers 66R, 66G, and 66B are formed in patterns corresponding to the light-emitting elements (sometimes referred to as organic EL elements) that emit red, green, and blue light, respectively. The anode 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. Note that an insulating layer 69 is provided between the anodes 64 to prevent short-circuiting between the anode 64 and the cathode 68 due to foreign matter. Furthermore, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 70 is provided to protect the organic EL elements from moisture and oxygen.

[0076] 7(b), the hole transport layer 65 and the electron transport layer 67 are shown as a single layer, but they may be formed of multiple layers including a hole blocking layer and an electron blocking layer depending on the structure of the organic EL display element. Also, a hole injection layer having an energy band structure that can smoothly inject holes from the anode 64 into the hole transport layer 65 can be formed between the anode 64 and the hole transport layer 65. Similarly, an electron injection layer can be formed between the cathode 68 and the electron transport layer 67.

[0077] Next, an example of a manufacturing method for an organic EL display device will be described in detail. First, a substrate 63 is prepared on which a circuit (not shown) for driving the organic EL display device and an anode 64 are formed. 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 by lithography so as to form an opening in the area where the anode 64 is formed, thereby forming an insulating layer 69. This opening corresponds to the light-emitting region where the light-emitting element actually emits light.

[0078] The substrate 63 on which the insulating layer 69 has been patterned is carried into a first organic material film forming apparatus, and the substrate is held by an electrostatic chuck. A hole transport layer 65 is then formed on the anode 64 in the display area as a common layer. The hole transport layer 65 is formed by vacuum deposition. In practice, the hole transport layer 65 is formed to be larger than the display area 61, so a high-resolution mask is not required.

[0079] Next, the substrate 63 on which the hole transport layer 65 has been formed is carried into a second organic material film forming apparatus and held by an electrostatic chuck. The substrate and a mask are aligned, and the mask is held over the substrate by the electrostatic chuck. A red light-emitting layer 66R is formed on the portion of the substrate 63 where the red light-emitting element is to be disposed.

[0080] Similar to the formation of the light-emitting layer 66R, a green-emitting light-emitting layer 66G is formed by a third organic material film-forming apparatus, and then a blue-emitting light-emitting layer 66B is formed by a fourth organic material film-forming apparatus. After the formation of the light-emitting layers 66R, 66G, and 66B is completed, an electron transport layer 67 is formed over the entire display area 61 by a fifth film-forming apparatus. The electron transport layer 67 is formed as a layer common to the three light-emitting layers 66R, 66G, and 66B.

[0081] The substrate on which the electron transport layer 67 has been formed is transferred through a metallic vapor deposition material deposition apparatus, where a cathode 68 is deposited. The substrate is then transferred to a plasma CVD apparatus, where a protective layer 70 is deposited, completing the organic EL display device 60. If the substrate 63 on which the insulating layer 69 has been patterned is exposed to an atmosphere containing moisture or oxygen after being transferred into the deposition apparatus until the deposition of the protective layer 70 is completed, the light-emitting layer made of the organic EL material may be deteriorated by the moisture or oxygen. Therefore, in this embodiment, the substrate is transferred between the deposition apparatuses in a vacuum atmosphere or an inert gas atmosphere.

[0082] The above-described embodiment is an example of the present invention, and the present invention is not limited to the configuration of the above-described embodiment, and may be appropriately modified within the scope of the technical concept thereof.

[0083] 20: camera, 24: electrostatic chuck, 30: electrostatic chuck system, 40: control unit, H: through hole

Claims

1. An electrostatic chuck system comprising: an electrostatic chuck for attracting an object to be attracted, the electrostatic chuck having at least one cutout portion extending from an attracting surface that attracts the object to an opposite surface; an imaging means for imaging the object through the cutout portion; and a determination means for determining a degree of attraction between the electrostatic chuck and the object to be attracted based on an image of the object to be attracted captured by the imaging means.

2. An electrostatic chuck system according to claim 1, wherein the determination of the degree of attraction by the determination means is a determination of whether or not the attraction of the object to be attracted to the electrostatic chuck is good.

3. An electrostatic chuck system according to claim 1, wherein the determination of the degree of attraction by the determination means is a determination of whether the object is attracted to the electrostatic chuck or detached from the electrostatic chuck.

4. An electrostatic chuck system according to any one of claims 1 to 3, wherein the determining means determines the degree of attraction based on an image of a determination mark provided on the object to be attracted.

5. An electrostatic chuck system according to claim 4, wherein said determining means determines said degree of attraction by pattern matching an image of a determination mark provided on said object to be attracted with a predetermined model image.

6. An electrostatic chuck system according to claim 4, wherein the determining means determines the degree of attraction based on a feature amount of an image of a determination mark provided on the object to be attracted.

7. An electrostatic chuck system according to claim 6, wherein the characteristic amount is at least one of chromaticity, luminance, and saturation.

8. An electrostatic chuck system according to any one of claims 1 to 3, wherein the cutout portion is a through hole that penetrates the electrostatic chuck.

9. An electrostatic chuck system according to any one of claims 1 to 3, characterized in that the cutout portion is provided at a corner portion of the rectangular electrostatic chuck.

10. An electrostatic chuck system according to any one of claims 1 to 3, characterized in that the cutout portion is provided in the center of the electrostatic chuck.

11. An electrostatic chuck system according to any one of claims 1 to 3, wherein the object to be attracted is a substrate.

12. A film forming apparatus comprising the electrostatic chuck system according to claim 11, for forming a film on the substrate through a mask.

13. A method for attracting an object to be attracted to an electrostatic chuck, the method comprising: a step of: forming at least one cutout portion in the electrostatic chuck, the cutout portion penetrating from the attracting surface that attracts the object to the opposite surface; and a step of: photographing the object through the cutout portion by an imaging means; and a step of determining the degree of adhesion between the electrostatic chuck and the object to be attracted based on the image of the object to be attracted taken in the imaging step.

14. A method for forming a film of a vapor deposition material on a substrate through a mask, comprising the steps of: carrying a mask into a vacuum vessel; carrying a substrate into the vacuum vessel; adsorbing the substrate to an electrostatic chuck having at least one notch extending from an adsorption surface that adsorbs the substrate to an opposite surface; photographing the substrate through the notch with an imaging means; determining a degree of adsorption of the electrostatic chuck and the substrate based on an image of the substrate photographed in the photographing step; adsorbing the mask to the electrostatic chuck through the substrate; and releasing the vapor deposition material while the substrate and the mask are adsorbed to the electrostatic chuck, thereby forming a film of the vapor deposition material on the substrate through the mask.

15. A method for manufacturing an electronic device, comprising the steps of: forming an electronic device by using the film forming method according to claim 14;

Images