Film forming apparatus, alignment method, and method for manufacturing electronic device

Abstract

Provided is a film formation apparatus capable of improving positioning accuracy of a substrate and a mask, an alignment method, and a method for manufacturing an electronic device. A film formation apparatus (1) that forms a thin film on a substrate (30) via a mask (40) is characterized by comprising: a mask placement stage (124) having a positioning member (125) that positions the mask (40); an optical fiber (72) disposed on the mask placement stage (124) and constituting a confirmation mechanism that confirms a positional relationship of the mask (40) positioned by the positioning member (125) with respect to the substrate (30); and a flow path (83) disposed on the mask placement stage (124) and disposed between the optical fiber (72) and the positioning member (125).

Description

Technical Field

[0001] This invention relates to film-forming apparatus, alignment method, and method for manufacturing electronic devices. Background Technology

[0002] Organic EL (OLED) displays are used not only in smartphones, televisions, and automotive displays, but also in VR HMDs (Virtual Reality Head-Mount Displays), demonstrating their wide range of applications. In particular, displays used in VR HMDs require high-precision pixel pattern formation and further resolution to reduce user dizziness.

[0003] In the manufacture of organic EL display devices, during the formation of the organic light-emitting elements (organic EL elements; OLEDs) constituting the OLED display device, film-forming material emitted from a film-forming source is deposited onto a substrate through a mask with a pixel pattern, thereby forming an organic layer and a metal layer. In such a device, to improve film-forming accuracy, the relative positional relationship between the substrate and the mask is measured (confirmed) before the film-forming process. If the positional relationship deviates, an alignment process is performed to adjust the position by moving the substrate and the mask relative to each other. In this process, a method is often used where an alignment mark formed on at least one of the substrate and the mask is photographed by an imaging mechanism such as a camera, and the relative positional relationship between the substrate and the mask is determined by detecting this mark.

[0004] With the increasing resolution of displays, the allowable error for substrate positioning has become increasingly stringent. High precision of less than 10 μm is typically required, and in recent years, requirements for precision of less than 3 μm have become commonplace. Furthermore, the latest VR and HMD applications demand even higher precision, sometimes reaching less than 1 μm. Therefore, as mentioned above, an alignment process is typically added before the film deposition process to position the substrate. In cases where the method of photographing marks using a camera is employed, as described above, to improve mark recognition efficiency, methods are known to place a light source or light guide at a position facing the camera across the mark. For example, Patent Document 1 discloses a technique in which, in order to guide light into the interior of a device under vacuum conditions, an optical fiber is used as a light guide through an inlet portion on the device wall, thereby illuminating the mark at a desired location.

[0005] In this technology, the light guide heats up due to energy loss during light introduction. Consequently, the component housing the light guide deforms due to linear expansion. When this component employs a mask-mounting structure, the mask's positioning may become unstable due to the aforementioned linear expansion.

[0006] [Existing Technical Documents]

[0007] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2013-1947 Summary of the Invention

[0009] [The problem the invention aims to solve]

[0010] For example, in cases where high precision is required, with the relative positional deviation between the substrate and the mask being less than 1 μm, the decrease in mask positioning accuracy due to the linear expansion of the components that hold the mask, which was not a problem in the past, becomes an issue.

[0011] The purpose of this invention is to provide a film forming apparatus, an alignment method, and a method for manufacturing electronic devices that can improve the positioning accuracy of a substrate and a mask.

[0012] [Solution to the problem]

[0013] To address the aforementioned issues, the present invention employs the following solution.

[0014] The film-forming apparatus of the present invention is a film-forming apparatus for forming a thin film on a substrate via a mask, characterized in that,

[0015] The film-forming apparatus includes:

[0016] A mask mounting stage, the mask mounting stage having a positioning member for positioning the mask;

[0017] A confirmation mechanism component is disposed on the mask mounting stage, constituting a confirmation mechanism for confirming the relative positional relationship between the mask and the substrate positioned by the positioning component.

[0018] A cooling mechanism is disposed on the mask mounting platform and between the confirmation mechanism component and the positioning component.

[0019] The alignment method of the present invention is an alignment method for positioning a substrate, which is the object of film formation, relative to a mask disposed on the film-forming surface side of the substrate during film formation, characterized in that...

[0020] The alignment method includes:

[0021] The positioning process involves positioning the mask towards a positioning component disposed on a mask mounting stage.

[0022] In the cooling process, a cooling mechanism cools the area between the positioning member and the confirmation mechanism component in the mask mounting stage. The confirmation mechanism component is disposed on the mask mounting stage and constitutes a confirmation mechanism for confirming the relative positional relationship between the mask and the substrate; and

[0023] The alignment process involves positioning the substrate relative to the mask while the mask stage is being cooled by the cooling mechanism.

[0024] The method for manufacturing the electronic device of the present invention is characterized in that, after the relative positioning of the substrate and the mask is performed by the alignment method described above, a film-forming step is included in forming a film on the substrate.

[0025] [Invention Effects]

[0026] As described above, the positioning accuracy of the substrate and the mask can be improved according to the present invention. Attached Figure Description

[0027] Figure 1 This is a schematic structural diagram of the internal structure of the film-forming apparatus of Example 1, viewed from the front side.

[0028] Figure 2 This is a schematic cross-sectional view of the film-forming apparatus of Example 1.

[0029] Figure 3 This is a flowchart of the alignment operation of the film-forming apparatus in Example 1.

[0030] Figure 4 This is a schematic structural diagram of the internal structure of the film-forming device of Example 2, viewed from the front side.

[0031] Figure 5 This is a schematic cross-sectional view of the film-forming apparatus of Example 2.

[0032] Figure 6 It is an overall view of the organic EL display device and a cross-sectional view of the components of the organic EL display device. Detailed Implementation

[0033] Hereinafter, with reference to the accompanying drawings, embodiments for carrying out the present invention will be described in detail illustratively. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the structural components described in these embodiments are not intended to limit the scope of the present invention.

[0034] (Example 1)

[0035] Reference Figures 1-3 This describes the film-forming apparatus, alignment method, and manufacturing method of electronic devices according to Embodiment 1 of the present invention. Figure 1 This is a schematic structural diagram of the internal structure of the film-forming apparatus of Example 1, viewed from the front side. Figure 2 This is a schematic cross-sectional view of the film-forming apparatus of Example 1, equivalent to Figure 1 The AA sectional view in the figure roughly shows the structure of each part. Figure 3 This is a flowchart of the alignment operation of the film-forming apparatus in Example 1. It should be noted that... Figure 1 and Figure 2 The image briefly illustrates the various structures external to the chamber of the film-forming apparatus. Furthermore, in... Figure 1 and Figure 2 The diagram shows the X, Y, and Z axes. The Z-axis extends parallel to the vertical direction, while the X and Y axes extend parallel to the horizontal plane, with the X and Y axes being orthogonal. It should be noted that in the following description, the direction of rotation about a central axis parallel to the X-axis is called the "θx direction," the direction of rotation about a central axis parallel to the Y-axis is called the "θy direction," and the direction of rotation about a central axis parallel to the Z-axis is called the "θz direction."

[0036] <Film Forming Device>

[0037] The film-forming apparatus 1 includes a chamber 10 and a film-forming unit 20 disposed inside the chamber 10. The chamber 10 is generally composed of a chamber sidewall 11, a chamber top plate 12, and a chamber bottom plate 13. These are fixed in an airtight state by welding or sealing members (not shown), thereby forming the chamber 10. As a result, the interior of the chamber 10 can be maintained in a vacuum atmosphere or an inactive gas atmosphere. The chamber 10 is supported by a support platform (not shown). A portion of this support platform is mounted on the ground on which the film-forming apparatus 1 is disposed, thereby fixing it relative to the chamber 10 and the ground. The film-forming unit 20 is disposed on the chamber bottom plate 13. The film-forming unit 20 is composed of a film-forming source 21 that releases the film-forming material, a linear motion guide 22 that enables the film-forming source 21 to reciprocate, and a mechanism (not shown) that reciprocates the film-forming source 21 along the linear motion guide 22. Since the film-forming source 21 has a limited range of film-forming capability, it is configured to perform film-forming while reciprocating, thereby enabling film formation over a large area. The film-forming material emitted from the film-forming source 21 adheres to the substrate 30 via a mask 40 disposed above the film-forming source 21, thereby forming a thin film on the substrate 30, which is the object of film formation.

[0038] When the vacuum evaporation apparatus is used as the film-forming apparatus 1, the film-forming source 21 is an evaporation source. The film-forming material (evaporation material) evaporates or sublimates from the film-forming source 21 and passes through the opening of the mask 40, forming a thin film on the substrate 30. Since the evaporation source is known technology, it will be briefly described here. For example, the evaporation source consists of a container (crucible) for containing the film-forming material, a heater for heating the container, a baffle for stopping the release of the film-forming material, a drive mechanism for driving various components such as the baffle, and an evaporation rate monitor for identifying the thickness of the film formed. It should be noted that the film-forming source of the present invention is not limited to an evaporation source. When the sputtering apparatus is used as the film-forming apparatus 1, the film-forming source is equivalent to a sputtering target.

[0039] An opening is provided in the mask 40 at a position corresponding to the location where a thin film is formed on the substrate 30, covering the position on the substrate 30 where a thin film will not be formed. Thus, by forming a film on the substrate 30 via the mask 40, a thin film with the desired pattern (the pattern corresponding to the position where the opening is provided) is formed on the substrate 30. It should be noted that the mask 40 in this embodiment is composed of a high-rigidity mask frame 41 disposed on the outer periphery and a low-rigidity mask foil 42 disposed inside the mask frame 41, with the aforementioned opening provided in the mask foil 42.

[0040] In the film-forming apparatus 1, a mechanism is provided for aligning the substrate 30 and the mask 40 (adjusting their relative positional relationship). Typically, alignment of the substrate and mask can be achieved by providing a mechanism that allows at least one of the substrate and mask to be moved and adjusted along at least three axes (X-axis, Y-axis, and Z-axis) and the θz direction. Such a structure is also employed in this invention. In this embodiment, an example will be described using a structure capable of moving and adjusting the mask 40 along three axes, along the θz direction, and also along the θx and θy directions. It should be noted that in this embodiment, the substrate 30 may be configured to be unable to be moved or adjusted, or it may be configured to be able to be moved and adjusted only along the Z-axis direction, or it may be configured to be able to be moved and adjusted in multiple directions, similar to the mask 40. Figure 1 The image shows the state after alignment is completed, with the mask 40 in contact with the film-forming surface of the substrate 30. The mechanism for moving and adjusting the mask 40 will be described below.

[0041] <Mechanism for moving and adjusting the mask>

[0042] A mask support mechanism 100 is provided on the top plate 12 of the chamber to support the mask 40 and adjust the position of the mask 40. The mask support mechanism 100 is generally composed of an alignment mechanism 110 for adjusting the position of the mask 40 and a holding mechanism 120 for holding the mask 40.

[0043] The alignment mechanism 110 includes a linear motion guide 111 for moving the mask 40 along the X-axis, a linear motion guide 112 for moving the mask along the Y-axis, and a rotary bearing 113 for rotating the mask 40 along the θz direction, all of which are interconnected. Furthermore, the alignment mechanism 110 includes a drive motor 114 for driving these components. Additionally, the alignment mechanism 110 includes a connecting plate 115 for connecting the holding mechanism 120 to the upper surface of the linear motion guide 111. It should be noted that the alignment mechanism 110 is positioned at the four corners of the connecting plate 115. Driven by the drive motor 114, the connecting plate 115 can move along the X-axis and Y-axis, and can rotate along the θz direction.

[0044] The retaining mechanism 120 includes a lifting drive unit 121 mounted on the connecting plate 115 and a lifting plate 122 connected to the lifting drive unit 121. The lifting drive unit 121 has the function of raising and lowering the lifting plate 122 along the Z-axis direction by an actuator (not shown). The lifting drive unit 121 is preferably provided at three equidistant locations (in...) Figure 1 (Only two locations are shown in the image). It should be noted that various known technologies, such as ball screw mechanisms and rack and pinion mechanisms, can be used as the aforementioned actuators. Furthermore, a mask mounting stage 124 is mounted on the lifting plate 122 via a support column 123. The support column 123 passes through a through hole 12a provided in the top plate 12 of the chamber, connecting the mask mounting stage 124 inside the chamber to the lifting plate 122 outside the chamber. To maintain a vacuum environment inside the chamber, a bellows 50 is installed on the support column 123 and the top plate 12 of the chamber. By synchronously driving multiple lifting drive units 121, the mask 40 can be moved linearly along the Z-axis direction. By imparting different amounts of movement, the mask 40 can change its posture along the direction of rotation (tilt) relative to the θx direction and the direction of rotation (tilt) relative to the θy direction. With the above structure, the mask 40 can be driven in a total of six axes, including three directional axes and three rotational axes, and the mask 40 can be moved relative to the substrate 30 to achieve position alignment.

[0045] A positioning member 125 for positioning the mask 40 is provided on the upper surface of the mask mounting stage 124. In this embodiment, the positioning member 125 has a mounting surface that is V-shaped when viewed from the side. Furthermore, a semi-cylindrical positioning block 43 is provided on the lower surface of the mask 40. By placing the positioning block 43 on the positioning member 125, the cylindrical portion of the positioning block 43 engages with the V-shaped mounting surface of the positioning member 125 in multiple locations, allowing the mask 40 to be positioned on the mask mounting stage 124. It should be noted that in this embodiment, the positioning member 125 and the positioning block 43 are provided at three locations. By placing the mask 40 on the mask mounting stage 124 configured in this way, the mask 40 is positioned above the film-forming source 21 in the vertical direction.

[0046] To suppress thermal deformation of the mask mounting stage 124, the material of the mask mounting stage 124 could be ceramic or a low-thermal-expansion material with a low coefficient of linear expansion. However, in the film-forming apparatus 1, since the film-forming material accumulates on the mask 40 over time through the film-forming process, the mask 40 needs to be replaced when a certain amount of film has been used. When replacing the mask, an impact load is transmitted to the mask mounting stage 124 when the mask 40 is placed on it. When ceramic is used as the material of the mask mounting stage 124, the ceramic has low impact resistance and a high risk of breakage. When a low-thermal-expansion material is used as the material of the mask mounting stage 124, the low hardness of the low-thermal-expansion material poses a risk of local skewing near the positioning member 125 in the mask mounting stage 124 due to the weight of the mask 40 and the impact during positioning. Based on the above, it is desirable to use stainless steel as the material of the mask mounting stage 124.

[0047] In addition, the film-forming apparatus 1 includes a control unit C. The control unit C has functions such as controlling the film-forming source 21 and controlling the alignment of the substrate 30 and the mask 40, as well as controlling various other devices. The control unit C can be configured as a computer having, for example, a processor, memory, external storage, and I / O. In this case, the functions of the control unit C are implemented by the processor executing programs stored in memory or storage devices. As the computer, a general-purpose personal computer, an embedded computer, or a PLC (programmable logic controller) can be used. Alternatively, circuits such as ASICs or FPGAs can be used to constitute part or all of the functions of the control unit C.

[0048] <Aim>

[0049] The alignment of the substrate and mask is explained. Since the alignment of the substrate and mask is a known technique, a brief explanation is provided here. Typically, at least one of the substrate and mask has alignment marks. For example, a structure can be used where marks are set on both, and these marks are photographed using a camera or other imaging mechanism, adjusting the position of at least one of the substrate and mask in such a way that the distance between the marks converges within a predetermined threshold. Alternatively, a structure can be used where a through-hole is provided on one of the substrate and mask, and a mark is set on the other, and the mark is photographed using a camera. In this case, the position of at least one of the substrate and mask can be adjusted as long as the distance between the center of the mark and the center of the through-hole converges within a predetermined threshold. Furthermore, if one of the substrate and mask is positioned within a device, and the positional relationship between that one and the camera is determined, it is sufficient to set a mark only on the other side. In this case, the position of the other side can be adjusted as long as the distance between a predetermined position (also called a virtual mark) in the image captured by the camera and the mark converges within a predetermined threshold.

[0050] In this embodiment, the various structures described above can also be used. In this embodiment, such as... Figure 1 As shown, a structure is employed where a camera 60, acting as the imaging mechanism, captures images of alignment marks placed on at least one of the substrate 30 and the mask 40. It should be noted that in both the substrate 30 and the mask 40, through-holes are provided in portions corresponding to the field of view of the camera 60, or at least portions corresponding to the field of view are constructed of light-transmitting components. The sensor of the camera 60 is preferably a structure sensitive to infrared wavelengths, in which case it is possible to capture images of either of the two components (substrate 30 and mask 40) in an overlapping state. Figure 1 As an example, an image captured by camera 60 is shown below when alignment marks 30M and 40M are respectively provided on substrate 30 and mask 40. In this embodiment, the position of mask 40 is adjusted such that the distance between these marks 30M and 40M is within a threshold value.

[0051] Furthermore, in this embodiment, to ensure mark contrast and improve mark recognition rate, a structure is adopted in which light is irradiated from below the mask 40 and received by the sensor of the camera 60. Thus, in this embodiment, the illumination unit 70, which includes the camera 60 and the light irradiation unit for aligning the marks, serves as a confirmation mechanism for confirming the relative positional relationship between the mask 40, which is positioned on the positioning member 125, and the substrate 30. The illumination unit 70 will be described below.

[0052] <Lighting Unit>

[0053] The illumination unit 70 includes a light source 71, an optical fiber 72 serving as a light guide that forms part of the light path for aligning the light from the light source 71, and a reflector 73. It should be noted that the optical fiber 72 can be referred to as a component of the confirmation mechanism. A through-hole is provided in the mask mounting stage 124, extending from the end face on the side of the light source 71 to the end face on the side of the reflector 73 (the opening face of the opening 124a provided in the center of the mask mounting stage 124), and a portion of the optical fiber 72 is inserted into this through-hole. By employing this structure, no space is needed around the mask mounting stage 124 to fix the optical fiber 72. Therefore, the distance between the film-forming source 21 and the substrate 30 can be shortened, and the phenomenon of film-forming material wrapping around the back of the mask foil 42 can be suppressed. Furthermore, the optical fiber 72 is led out from the inside of the chamber 10 to the outside through a through-hole 11a provided in the sidewall 11 of the chamber, and connected to the light source 71 provided outside the chamber 10. It should be noted that the through hole 11a is sealed by a cover 11b that maintains airtightness between it and the optical fiber 72.

[0054] With the above structure, the light from the light source 71 is guided by the optical fiber 72 through the through hole provided in the mask stage 124 to the end face of the reflector side (the opening face of the opening 124a). The light generated here causes a 90° phase change in the optical axis by means of the reflector 73. As a result, light is irradiated from below the substrate 30 and the mask 40, illuminating the alignment marks.

[0055] It should be noted that in this embodiment, a through-hole is provided in the mask mounting stage 124 to place the optical fiber 72. However, a slot can also be provided in the mask mounting stage 124 to place the optical fiber 72. Furthermore, in this embodiment, the positioning member 125 and the positioning block 43 are arranged in a total of three locations at approximately 120° equidistant angles, but their number and location are not limited. Similarly, in this embodiment, the illumination unit 70 is arranged in three locations, but its number and location are not limited. Additionally, in this embodiment, an optical fiber is used as a light guide, but other optical devices can also be used.

[0056] As described above, in this embodiment, an optical fiber 72, which serves as a component of the confirmation mechanism, is provided on the mask mounting stage 124. Therefore, this optical fiber 72 becomes a heat source, and due to deformation caused by the linear expansion of the mask mounting stage 124, the positioning accuracy of the positioning member 125 on the mask 40 may become unstable. Therefore, in this embodiment, a cooling device 80 is provided to suppress deformation caused by the linear expansion of the mask mounting stage 124. The cooling device 80 will be described below.

[0057] Cooling device

[0058] The cooling device 80 includes: a refrigerant control device 81 that circulates refrigerant (cooling water, solvent, etc.) and controls the cooling temperature; piping 82 for refrigerant flow; and a temperature measuring unit (temperature sensor T) for measuring the temperature of the mask stage 124. In this embodiment, a flow path (cooling mechanism) 83 for refrigerant flow is provided in the mask stage 124. That is, a portion of the refrigerant circulation path is provided in the mask stage 124. The flow path 83 provided in the mask stage 124 can be configured by embedding the piping 82 within the mask stage 124, or by providing a hole in the mask stage 124 to form the flow path 83. The piping 82 is preferably metal to maintain a vacuum environment inside the chamber. Moreover, similar to optical fiber 72, piping 82 is led out from the inside of chamber 10 to the outside through through hole 11a and connected to refrigerant control device 81, maintaining airtightness between piping 82 and cover 11b.

[0059] The flow path 83, which serves as a cooling mechanism, is disposed between the positioning member 125 and the optical fiber 72 on the mask mounting stage 124. In this embodiment, when viewed along the Z-axis, the positioning member 125 is arranged on both sides of the optical fiber 72, therefore the flow path 83 is disposed on both sides of the optical fiber 72. That is, the flow path 83 is arranged in two directions surrounding the optical fiber 72. Preferably, the flow path 83 is disposed near the optical fiber 72 in a manner that surrounds the optical fiber 72, and the shorter the distance between the flow path 83 and the optical fiber 72, the better the cooling effect. It should be noted that the flow path 83 is configured to reach the vicinity of the opening 124a of the mask mounting stage 124. However, if it is possible to set the flow path in the area within the opening 124a, it is also possible to... Figure 2 The portion above, surrounded by an ellipse, is shown in a structure with piping 84 connecting the flow path 83.

[0060] The temperature sensor T is located in the mask stage 124, near the optical fiber 72, between the optical fiber 72 and the flow path 83. The wire connected to the temperature sensor T, like the optical fiber 72 and the conduit 82, is led out from the inside of the chamber 10 to the outside through the through hole 11a and connected to the control unit C, maintaining an airtight seal between the wire and the cover 11b. This temperature sensor T enables real-time temperature measurement. A specific example of the temperature sensor T is a resistance thermometer.

[0061] In this embodiment, a structure is adopted in which the wires connected to the optical fiber 72, the conduit 82 and the temperature sensor T are led out from a common through hole 11a. However, different through holes may be provided according to the configuration structure, etc.

[0062] According to the cooling device 80 configured as described above, the refrigerant flows in a manner that circulates in the piping 82 and flow path 83 via the refrigerant control device 81. A cooler can be cited as a specific example of the refrigerant control device 81. Hereinafter, reference will be made to... Figure 3 This is an example illustrating the process of temperature control for the mask stage 124.

[0063] Mask 40 is placed on mask stage 124. When the position of mask 40 is adjusted by positioning member 125 (step S1 (positioning process)), the temperature obtained by temperature sensor T at this time is recorded in control unit C (step S2 (temperature measurement process)). Then, refrigerant circulation is started by refrigerant control device 81 (step S3 (cooling process)). When the alignment process between substrate 30 and mask 40 begins (step S4), illumination based on light source 71 is also started in illumination unit 70 (step S5). Then, the measured temperature obtained from temperature sensor T is transmitted to control unit C, and it is determined whether the measured temperature is within a threshold range predetermined based on the recorded temperature (measured temperature) (recorded measured temperature ± threshold) (step S6). Then, in order to make the successively measured temperature fall within this temperature range (recorded measured temperature ± threshold), control unit C controls refrigerant control device 81 by adjusting the refrigerant flow rate (step S7).

[0064] Therefore, if the measured temperature is within the aforementioned temperature range, the refrigerant flow rate is maintained (step S8), and the refrigerant flow rate is adjusted until alignment is complete. When alignment is complete (step S9), temperature control also ends (step SE). It should be noted that, as described above, the temperature measurement process is performed after the positioning process and before the confirmation based on the confirmation mechanism.

[0065] As described above, in this embodiment, the flow rate of the refrigerant flowing in the piping 82 is controlled so that the mask stage 124 is in thermal equilibrium. It should be noted that the temperature control process is not limited to the above-described process. For example, the recording of the measured temperature and the control of the refrigerant flow rate can begin simultaneously with the start of irradiation based on the light source 71. Furthermore, the refrigerant flow rate can be controlled before irradiation based on the light source 71. Moreover, while this embodiment shows temperature control by adjusting the refrigerant flow rate, a structure that controls the refrigerant temperature can also be used.

[0066] After the above alignment process is performed, a film is formed on the substrate 30 using the film forming source 21 (film forming process).

[0067] <Advantages of the film-forming apparatus and alignment method in this embodiment>

[0068] In this embodiment, by controlling the temperature of the mask mounting stage 124 during the alignment process, deformation of the mask mounting stage 124 due to linear expansion can be suppressed after the mask 40 is positioned on the mask mounting stage 124. Therefore, the positioning accuracy between the substrate 30 and the mask 40 can be improved.

[0069] (Example 2)

[0070] Figure 4 and Figure 5 Embodiment 2 of the present invention is shown. In Embodiment 1, a structure with an illumination unit as a confirmation mechanism was shown; however, in this embodiment, a structure with a measuring unit for measuring the distance between the substrate and the mask as the confirmation mechanism is shown. Other basic structures and functions are the same as in Embodiment 1; therefore, the same reference numerals are used for the same structural parts, and descriptions are appropriately omitted.

[0071] Figure 4 This is a schematic structural diagram of the internal structure of the film-forming device of Example 2, viewed from the front side. Figure 5 This is a schematic cross-sectional view of the film-forming apparatus of Example 2, equivalent to Figure 4 The BB sectional view in the figure roughly shows the structure of each part. Figure 4 and Figure 5 The various structures external to the chamber of the film-forming device are also briefly shown, and... Figure 1 and Figure 2 Similarly, the X, Y, and Z axes are shown.

[0072] In the film-forming apparatus 1A of this embodiment, similar to that of Embodiment 1, in addition to the chamber 10, film-forming unit 20, mask support mechanism 100, control unit C, etc., a cooling device 80 is also included. Their basic structure and operation are as described in Embodiment 1. It should be noted that this embodiment does not include the illumination unit 70 shown in Embodiment 1, but a structure including the illumination unit 70 can be adopted in the same manner as in Embodiment 1.

[0073] In the film-forming apparatus 1A of this embodiment, the substrate holding member 30X holding the substrate 30, like the mask stage 124, can be moved and adjusted along three axes, and can also be moved and adjusted in the θx, θy, and θz directions. Regarding the mechanism configured to move and adjust the substrate holding member 30X, the same structure as the mask support mechanism 100 can be used, or a structure in which the substrate holding member 30X is moved and adjusted in a suspended state using a linear motor can be used. It should be noted that, although not specifically illustrated, a structure can also be used where the drive source for driving the mechanism for moving and adjusting the substrate holding member 30X is connected to the control unit C via a wire, which also extends from the through hole 11a.

[0074] Furthermore, the film-forming apparatus 1A of this embodiment includes a measurement unit 90 as a verification mechanism for measuring the distance between the substrate 30 and the mask 40. This measurement unit 90 includes a sensor 91 disposed on the mask stage 124 and a target 92 disposed on the substrate holding member 30X. The sensor 91 and the target 92 are positioned facing each other. Using the sensor 91, which is a component of the verification mechanism, the distance to the target 92 can be measured, and thus the distance between the substrate 30 and the mask 40 can be measured. Moreover, the signal line of the sensor 91 is led out from the inside of the chamber 10 to the outside through a through-hole 11a and connected to the control unit C, maintaining an airtight seal between the signal line and the cover 11b. With such a sensor 91, the distance between the substrate 30 and the mask 40 can be measured in real time. An eddy current sensor can be cited as a specific example of the sensor 91.

[0075] Multiple measuring units 90 are provided at various locations. By obtaining data from all measuring units 90, the positional deviation between the substrate 30 and the mask 40, and the deviation of the substrate 30's orientation relative to the mask 40, can be measured (confirmed). Based on these deviations, the control unit C adjusts the position of the substrate holding member 30X, thereby enabling alignment between the substrate 30 and the mask 40. It should be noted that in this embodiment, the measuring units 90 are arranged in three locations at approximately 120° intervals, but the number and arrangement of the measuring units are not limited.

[0076] In this embodiment, the sensor 91, which is a component of the confirmation mechanism, becomes a heat source. Therefore, in this embodiment, the flow path 83, which serves as a cooling mechanism, is disposed between the positioning member 125 and the sensor 91. In this embodiment, the positioning member 125 is disposed on both sides of the sensor 91 when viewed along the Z-axis, and therefore the flow path 83 is disposed on both sides of the sensor 91. That is, the flow path 83 is disposed in two directions surrounding the sensor 91. Preferably, the flow path 83 is disposed near the sensor 91 in a manner that surrounds the sensor 91, and the shorter the distance between the flow path 83 and the sensor 91, the better the cooling effect. It should be noted that the flow path 83 extends to the vicinity of the opening 124a of the mask mounting stage 124. However, if it is possible to provide the flow path to the area within the opening 124a, as described in Embodiment 1, a structure in which a pipe is provided to connect the flow path 83 can also be used.

[0077] Temperature sensor T is positioned near sensor 91 within the mask stage 124. As described in Example 1, real-time temperature measurement is possible using this temperature sensor T.

[0078] In the film-forming apparatus 1A configured as described above, the distance from the substrate holding member 30X to the target 92 when it is stationary at a reference position is measured in advance by the sensor 91, and this value is set as a target value and recorded in the control unit C. Then, during the alignment process, the distance to the target 92 is measured in real time by the sensor 91, and the control unit C controls the position of the substrate holding member 30X in such a way that the measured value becomes the target value. Then, along with the power supply to the sensor 91, temperature control is performed in the mask stage 124 in the same manner as in Embodiment 1 to suppress deformation caused by linear expansion due to temperature rise near the sensor 91.

[0079] The following is a simplified explanation of an example of the temperature control process for the mask mounting stage 124. When the mask 40 is placed on the mask mounting stage 124, and the position of the mask 40 is adjusted by the positioning member 125 (positioning process), the temperature obtained by the temperature sensor T is recorded in the control unit C (temperature measurement process). Then, the refrigerant circulation is started by the refrigerant control device 81 (cooling process). When the alignment process between the substrate 30 and the mask 40 begins, power is supplied to the sensor 91. The measured temperature obtained from the temperature sensor T is then transmitted to the control unit C, which determines whether the measured temperature falls within a predetermined threshold range based on the recorded temperature (measured temperature) (recorded measured temperature ± threshold). Then, to ensure the temperature falls within this range, the control unit C controls the refrigerant control device 81 by adjusting the refrigerant flow rate. Therefore, if the measured temperature falls within the aforementioned temperature range, the refrigerant flow rate is maintained, and refrigerant flow rate adjustment is performed until alignment is completed. When alignment is completed, temperature control also ends.

[0080] In the film-forming apparatus 1A of this embodiment configured as described above, the same effects as in Embodiment 1 can be obtained. It should be noted that in this embodiment, the temperature control process is not limited to the process described above. For example, the recording of the measured temperature and the control of the refrigerant flow can begin simultaneously with the power supply to the sensor 91. Furthermore, the refrigerant flow can be controlled before powering on the sensor 91. In addition, in this embodiment, a structure that controls the temperature of the refrigerant can be used instead of adjusting the refrigerant flow. It should be noted that, as described above, in this embodiment, both the mask stage 124 and the substrate holding member 30X can be moved and adjusted along three axes, and can also be moved and adjusted in the θx, θy, and θz directions. For example, when adjusting the relative position of the substrate 30 and the mask 40, after adjusting the position within a specified range (e.g., up to 1 μm) using the mask stage 124, further fine-tuning (below 1 μm) can be performed using the substrate holding member 30X.

[0081] <Manufacturing Methods of Electronic Devices>

[0082] An example of a method for manufacturing an electronic device using the film-forming apparatus 1 and 1A of the above embodiments will be described. Hereinafter, as an example of an electronic device, the structure and manufacturing method of an organic EL display device will be illustrated. First, the manufactured organic EL display device will be described. Figure 6 (a) is an overall view of the organic EL display device 560. Figure 6 (b) represents the cross-sectional structure of a pixel.

[0083] like Figure 6 As shown in (a), a plurality of pixels 562, each having multiple light-emitting elements, are arranged in a matrix in the display area 561 of the organic EL display device 560. Each light-emitting element has an organic layer sandwiched between a pair of electrodes, as detailed below. It should be noted that a pixel, as used here, refers to the smallest unit in the display area 561 capable of displaying a desired color. In the case of the organic EL display device of this embodiment, the pixels 562 are constructed by a combination of a first light-emitting element 562R, a second light-emitting element 562G, and a third light-emitting element 562B that emit different colors. Pixels 562 are mostly composed of a combination of red, green, and blue light-emitting elements, but can also be a combination of yellow, cyan, and white light-emitting elements, as long as there is at least one color, there is no particular limitation.

[0084] Figure 6 (b) is Figure 6(a) is a partial cross-sectional view at line AB. Pixel 562 has an organic EL element on substrate 563, which includes a first electrode (anode) 564, a hole transport layer 565, any one of light-emitting layers 566R, 566G, and 566B, an electron transport layer 567, and a second electrode (cathode) 568. Among these, the hole transport layer 565, the light-emitting layers 566R, 566G, 566B, and the electron transport layer 567 are equivalent to organic layers. Moreover, in this embodiment, the light-emitting layer 566R is a red-emitting organic EL layer, the light-emitting layer 566G is a green-emitting organic EL layer, and the light-emitting layer 566B is a blue-emitting organic EL layer. The light-emitting layers 566R, 566G, and 566B are respectively formed in patterns corresponding to the red, green, and blue light-emitting elements (sometimes referred to as organic EL elements). Furthermore, the first electrode 564 is formed separately according to each light-emitting element. The hole transport layer 565, electron transport layer 567, and second electrode 568 can be formed together with multiple light-emitting elements 562R, 562G, and 562B, or they can be formed separately for each light-emitting element. It should be noted that an insulating layer 569 is provided between the first electrode 564 and the second electrode 568 to prevent short circuits due to impurities. Furthermore, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 570 is provided to protect the organic EL element from contact with moisture and oxygen.

[0085] exist Figure 6 In (b), the hole transport layer 565 and the electron transport layer 567 are represented by a single layer, but depending on the structure of the organic EL display element, they may also be formed by multiple layers including a hole blocking layer and an electron blocking layer. Furthermore, a hole injection layer with a band structure that allows for smooth injection of holes from the first electrode 564 to the hole transport layer 565 can also be formed between the first electrode 564 and the hole transport layer 565. Similarly, an electron injection layer can also be formed between the second electrode 568 and the electron transport layer 567.

[0086] Next, an example of a method for manufacturing an organic EL display device will be specifically described. First, a substrate 563 is prepared, which has a circuit (not shown) for driving the organic EL display device and a first electrode 564.

[0087] Acrylic resin is spin-coated onto a substrate 563 on which the first electrode 564 is formed. The acrylic resin is then patterned using photolithography to form an opening in the portion where the first electrode 564 is formed, thus forming an insulating layer 569. This opening corresponds to the light-emitting area where the light-emitting element actually emits light.

[0088] A substrate 563 with an insulating layer 569 patterned on it is fed into a first film-forming apparatus. The substrate is held by a substrate support unit, and a hole transport layer 565 is formed as a common layer on the first electrode 564 of the display area. The hole transport layer 565 is formed by vacuum evaporation. In fact, the hole transport layer 565 is formed to a size larger than the display area 561, so a high-precision mask is not required.

[0089] Next, the substrate 563 with the hole transport layer 565 formed thereon is fed into the second film deposition apparatus and held by the substrate support unit. Alignment (first alignment and second alignment) is performed between the substrate and the mask, the substrate is placed on the mask, and a red light-emitting layer 566R is formed on the portion of the substrate 563 that emits red elements.

[0090] Similar to the deposition of the light-emitting layer 566R, a green light-emitting layer 566G is deposited using the third film deposition apparatus, and a blue light-emitting layer 566B is deposited using the fourth film deposition apparatus. After the deposition of the light-emitting layers 566R, 566G, and 566B is completed, an electron transport layer 567 is deposited over the entire display area 561 using the fifth film deposition apparatus. The electron transport layer 567 forms a common layer across the three-color light-emitting layers 566R, 566G, and 566B.

[0091] The substrate to which the electron transport layer 567 is formed is moved toward the sputtering apparatus to form the second electrode 568, and then moved toward the plasma CVD apparatus to form the protective layer 570, thus completing the organic EL display device 560.

[0092] From the moment the substrate 563 with the insulating layer 569 is fed into the film-forming apparatus until the film-forming of the protective layer 570 is completed, if exposed to an atmosphere containing moisture and oxygen, the light-emitting layer made of organic EL material may deteriorate due to moisture and oxygen. Therefore, in this example, the feeding and unloading of the substrate between the film-forming apparatuses is performed under a vacuum atmosphere or an inactive gas atmosphere.

[0093] [Explanation of Labels in the Attached Image]

[0094] 1. 1A: Film forming apparatus; 10: Chamber; 20: Film forming unit; 21: Film forming source; 30: Substrate; 30X: Substrate holding member; 40: Mask; 43: Positioning block; 50: Bellows; 60: Camera; 70: Illumination unit; 71: Light source; 72: Fiber optic cable; 73: Reflector; 80: Cooling device; 81: Refrigerant control device; 82: Piping; 83: Flow path; 84: Piping; 90: Measurement unit; 91: Sensor; 92: Target; 100: Mask support mechanism; 110: Alignment mechanism; 111, 112: Linear movement guide; 113: Rotary bearing; 114: Drive motor; 115: Connecting plate; 120: Holding mechanism; 121: Lifting drive unit; 122: Lifting plate; 123: Support column; 124: Mask mounting stage; 124a: Opening; 125: Positioning member; C: Control unit; T: Temperature sensor.

Claims

1. A film-forming apparatus for forming a thin film on a substrate via a mask, characterized in that, The film-forming apparatus includes: A mask mounting stage, the mask mounting stage having a positioning member for positioning the mask; A confirmation mechanism component is disposed on the mask mounting stage, constituting a confirmation mechanism for confirming the relative positional relationship between the mask and the substrate positioned by the positioning component. as well as A cooling mechanism is disposed on the mask mounting platform and between the confirmation mechanism component and the positioning component.

2. The film-forming apparatus according to claim 1, characterized in that, The cooling mechanism is arranged in at least two directions surrounding the constituent components of the confirmation mechanism.

3. The film-forming apparatus according to claim 1 or 2, characterized in that, The verification mechanism includes a light source and a light guide, the light guide forming part of a light path that guides the light from the light source toward alignment marks disposed on at least one of the substrate and the mask. The component of the confirmation mechanism is the light introducer.

4. The film-forming apparatus according to claim 3, characterized in that, The light importer is an optical fiber.

5. The film-forming apparatus according to claim 1 or 2, characterized in that, The verification mechanism includes a target and a sensor. The target is disposed on a substrate holding member that holds the substrate, and the sensor is disposed on the mask stage for measuring the distance to the target. The sensor is a component of the confirmation mechanism.

6. The film-forming apparatus according to claim 1 or 2, characterized in that, The cooling mechanism is configured as a flow path for the refrigerant to flow.

7. The film-forming apparatus according to claim 6, characterized in that, The flow rate of the refrigerant flowing in the flow path is controlled in such a way that the mask stage is in thermal equilibrium.

8. An alignment method, wherein the alignment method performs relative positioning of a substrate, which is a film-forming object, and a mask disposed on the film-forming surface side of the substrate during film formation, characterized in that, The alignment method includes: The positioning process involves positioning the mask towards a positioning component disposed on a mask mounting stage. In the cooling process, the area between the positioning member and the confirmation mechanism component is cooled by a cooling mechanism on the mask mounting stage. The confirmation mechanism component is disposed on the mask mounting stage and constitutes a confirmation mechanism for confirming the relative positional relationship between the mask and the substrate. The alignment process involves positioning the substrate relative to the mask while the mask stage is being cooled by the cooling mechanism.

9. The alignment method according to claim 8, characterized in that, The alignment method, following the positioning process and before the confirmation by the confirmation mechanism, includes a temperature measurement process that measures and stores the temperature of the mask stage. During the cooling process, the temperature of the mask stage is maintained within a threshold range based on the measured temperature.

10. A method for manufacturing an electronic device, characterized in that, After the relative positioning of the substrate and the mask is performed by the alignment method described in claim 8 or 9, a film-forming step is performed on the substrate.

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