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

Abstract

The present invention provides a film-forming apparatus, a film-forming method, and a method for manufacturing electronic devices capable of stably cooling a mask. A film-forming apparatus (1) forms a thin film on a substrate (S) within a chamber (10) by means of a film-forming material emitted from a film-forming source (110) via a mask (M), characterized in that the film-forming apparatus includes a radiation cooling member (130) disposed at a position that does not obstruct the path of the film-forming material from the film-forming source (110) to the substrate (S) in a film-forming range (R), and has a cooling surface (131) capable of heat exchange via radiation, the temperature of the radiation cooling member (130) being controlled according to the thickness of the film of the film-forming material formed on the cooling surface (131).

Description

Technical Field

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

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

[0003] In the manufacturing of organic EL display devices, when forming organic light-emitting elements (organic EL elements; OLEDs) that constitute organic EL display devices, film-forming materials emitted from a film-forming source are deposited on a substrate through a mask with a pixel pattern to form an organic layer and a metal layer.

[0004] In this film formation method, thermal radiation energy is released along with the film-forming material from the film formation source. Due to the thermal radiation from the film formation source, especially the mask, the mask heats up and thermally expands, causing a change in the relative position between the mask and the substrate. If the relative position between the mask and the substrate changes during film formation, it is impossible to form pixel patterns with high precision; therefore, mask cooling is particularly necessary.

[0005] Typically, heat transfer methods such as conduction, convection, and radiation can be used to cool objects. However, in the aforementioned film deposition method, since film deposition takes place within a vacuum chamber, convection cannot be utilized, requiring either heat conduction or radiation. Regarding heat conduction, its use is limited due to several factors, including the tendency for increased in-plane thermal resistance caused by the thinning of the mask as pixel patterns become more refined, and the difficulty in managing the contact state with the substrate, leading to deviations in contact thermal resistance. Therefore, radiation is considered the preferred method for cooling the mask during the aforementioned film deposition process.

[0006] When radiatively cooling a mask, it is effective to arrange a radiative cooling member with a surface that can maintain a lower temperature compared to the heated portion of the mask, relative to the heated portion. For example, Patent Document 1 discloses a technique related to a radiative cooling member that covers the heated portion of the mask in a hemispherical shape. However, the technique disclosed in Patent Document 1 is geared towards an EB exposure apparatus and does not envision the formation of a film on the surface of the radiative cooling member due to the scattering of particles of the film-forming material emitted from the film-forming source. In an environment where such a film is formed, there are problems such as the need for regular cleaning or the cooling capacity changing as the film thickness increases.

[0007] Furthermore, Patent Document 2 discloses a technique of arranging a radiation cooling member on the back side of an anti-adhesion plate covering the entire interior of a cavity. In this technique, in a film-forming apparatus, a radiation cooling member is arranged on the back side of the anti-adhesion plate to prevent the formation of a film on the surface of the radiation cooling member due to the scattering of film-forming material emitted from the film-forming source. In this case, there are problems that the cooling function of the radiation cooling member is difficult to fully utilize because the mask is cooled through the anti-adhesion plate, and the cooling capacity changes as the thickness of the film formed on the surface of the anti-adhesion plate increases.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2000-349023

[0011] Patent Document 2: Japanese Patent Application Publication No. 2021-080559 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] As mentioned above, even if a radiation cooling component is provided in the film-forming apparatus, the mask cannot be cooled stably due to the adhesion of the film-forming material, making it difficult to improve the film-forming accuracy.

[0014] The purpose of this invention is to provide a film-forming apparatus, a film-forming method, and a method for manufacturing electronic devices that can stably cool a mask.

[0015] Solution for solving the problem

[0016] The film-forming apparatus of the present invention forms a thin film on a substrate within a chamber using a film-forming material emitted from a film-forming source via a mask, characterized in that...

[0017] The film-forming apparatus includes a radiation cooling member disposed at a position that does not obstruct the path of the film-forming material from the film-forming source to the film-forming area of ​​the substrate, and has a cooling surface capable of heat exchange via radiation.

[0018] The temperature of the radiative cooling component is controlled based on the thickness of the film formed by the film-forming material on the cooling surface.

[0019] The effects of the invention

[0020] As explained above, the mask can be cooled stably according to the present invention. Attached Figure Description

[0021] Figure 1 This is a schematic structural diagram of the film-forming apparatus of Example 1.

[0022] Figure 2 This is a top view of the radiative cooling component of Embodiment 1.

[0023] Figure 3 This is a schematic cross-sectional view of the radiative cooling component, etc., of Embodiment 1.

[0024] Figure 4 This is a schematic cross-sectional view of the radiative cooling component, etc., of Embodiment 1.

[0025] Figure 5 This is a schematic structural diagram of the film-forming apparatus of Example 2.

[0026] Figure 6 This is an explanatory diagram of an organic EL display device. Detailed Implementation

[0027] Hereinafter, with reference to the accompanying drawings, embodiments will be described in detail illustratively. However, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the constituent components described in this embodiment are not intended to limit the scope of the invention.

[0028] (Example 1)

[0029] Reference Figures 1-4 The film-forming apparatus, film-forming method, and electronic device manufacturing method of Embodiment 1 of the present invention will be described. Figure 1 This is a schematic structural diagram of the film-forming apparatus according to Embodiment 1 of the present invention. Figure 1 The diagram outlines the internal structure of the device, with a portion of the structure shown in a schematic cross-sectional view. Figure 2 This is a top view of the radiative cooling component of Embodiment 1 of the present invention. Figure 1 The cross-sectional view of the radiation cooling component in the middle is equivalent to Figure 2 AA section view in the image. Figure 3 and Figure 4 This is a schematic cross-sectional view of the radiative cooling component, etc., according to Embodiment 1 of the present invention. Figure 3 This is a diagram illustrating the heat exchange during film formation. Figure 4 This is a diagram showing the situation of particles that act as film-forming materials during film formation.

[0030] <Film Forming Device>

[0031] The film-forming apparatus 1 includes a chamber 10 and a film-forming unit 100 disposed inside the chamber 10. The interior of the chamber 10 is configured to maintain a vacuum environment or an inactive gas environment. The film-forming unit 100 includes: a film-forming source 110 for releasing film-forming material; a limiting member 120 for limiting the irradiation direction of the film-forming material; a radiation cooling member 130; and a film thickness gauge 140. In this embodiment, the film-forming apparatus 1 is a vacuum evaporation apparatus, and the film-forming source 110 is an evaporation source. The film-forming material (evaporation material) evaporates or sublimates from the film-forming source 110, and through the opening of the mask M, the film-forming material is deposited on the substrate S to form a thin film. As the evaporation source is known technology, it will be described simply here. For example, the evaporation source consists of a container (crucible) for holding 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 the baffle and other various components, and an evaporation rate monitor for identifying the thickness of the film formed.

[0032] exist Figure 1 In this embodiment, the film-forming range formed by the film-forming unit 100 is the range shown in R. Thus, the film-forming range R formed by the film-forming unit 100 is limited. Therefore, the film-forming unit 100 is configured to perform film formation over a large area by being able to move along the track 20 provided in the chamber 10. Various known technologies, such as ball screw mechanisms and rack and pinion mechanisms, can be used for the mechanism that moves the film-forming unit 100. Furthermore, depending on the size of the substrate S, it is not necessary to provide a film-forming unit 100 that is movable by integrally forming the film-forming source 110, and a structure in which the film-forming source is fixed to the chamber 10 can also be used.

[0033] An opening is provided on the mask M at a position corresponding to the location where a thin film is formed on the substrate S, thus covering the position on the substrate S where no thin film is formed. Therefore, by depositing a film on the substrate S via the mask M, a thin film with the desired pattern (the pattern corresponding to the position where the opening is provided) is formed on the substrate S. The film deposition apparatus 1 is provided with a mechanism for adjusting the relative position of the substrate S and the mask M; however, since known techniques can be used for this mechanism, its description is omitted here. Furthermore, generally, film deposition is performed with the substrate and the mask in close contact.

[0034] Furthermore, the film-forming apparatus 1 includes a control unit C. The control unit C has functions such as controlling the film-forming source 110, controlling the alignment (relative position adjustment) of the substrate S and the mask M, and controlling various other devices. The control unit C can be, for example, a computer having a processor, memory, storage, I / O, etc. In this case, the functions of the control unit C are implemented by the processor executing a program stored in the memory or storage. 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 constitute part or all of the functions of the control unit C.

[0035] In this embodiment, as described above, a limiting member 120 is provided. This limiting member 120 is a box-shaped member with an opening 121 formed only on its top surface. As a result, only the fraction of vapor-deposited particles, which are the film-forming material emitted from the film-forming source 110, are selected and incident approximately perpendicularly to the substrate S and the mask M, reaching and depositing on the substrate S and the mask M. Simultaneously with the arrival of the vapor-deposited particles, radiative heat from the film-forming source 110 also reaches the film-forming range R, thus causing the temperature of the mask M and the substrate S to rise within this range R. In particular, in recent years, the mask M has become increasingly finer and thinner, resulting in a smaller heat capacity compared to the substrate S; therefore, the temperature of the mask M rises significantly. The typical temperature of the evaporation source 110 is around 400°C in the case of vapor-depositing organic materials, and sometimes exceeds 1000°C in the case of vapor-depositing metallic materials. The mask M and the substrate S are heated due to radiative heat transfer from this evaporation source. The temperatures of the mask M and substrate S vary depending on the device structure and the surface conditions (emissivity, etc.) of the components constituting the device. For example, assuming the distance from the evaporation source to the substrate S is approximately 1000 mm, the temperature of the mask M will rise by at least several to tens of degrees Celsius, and may rise further depending on the circumstances. Furthermore, the heat capacities of the mask M and substrate S differ. Generally, the heat capacity of a thin-film mask M is small, and it typically heats up within a few to tens of seconds upon receiving radiant energy. In contrast, the heating rate of the substrate S is often an order of magnitude slower or less than that of the mask M. Therefore, a relative thermal displacement occurs between the mask M and substrate S during evaporation, reducing the evaporation quality. For example, assuming the mask and substrate dimensions are 500 mm × 500 mm, the temperature difference between the mask M and substrate S is 2 degrees Celsius, and the coefficient of linear expansion is 2 × 10⁻⁶. －6 ℃ －1 The relative thermal displacement between the mask and the substrate is 500mm × 2℃ × 2 × 10. －6 ℃ －1=2μm. This is a size that cannot be ignored in vapor deposition processes requiring high precision, such as VRHMD. Furthermore, as the mask M becomes thinner, the thermal resistance in the in-plane direction of the mask increases, making it difficult to release heat through heat conduction. Therefore, in the film deposition apparatus 1 of this embodiment, a radiation cooling member 130 is provided.

[0036] <Radiation Cooling Components>

[0037] The radiation cooling member 130 will be described in detail. The radiation cooling member 130 is positioned so as not to obstruct the path of the film-forming material from the film-forming source 110 to the film-forming range R of the substrate S. More specifically, an opening 131a for the path of the film-forming material is provided at the center of the radiation cooling member 130. Thus, the radiation cooling member 130 is positioned so as not to obstruct the path of the film-forming material from the film-forming source 110 to the film-forming range R of the substrate S. Furthermore, the radiation cooling member 130 has a cooling surface 131 capable of heat exchange via radiation. This cooling surface 131 is configured such that the normal to its surface intersects the center (near the center) of the film-forming range R. In this embodiment, the cooling surface 131 is composed of a hemispherical surface, and the center of the hemisphere is located at the center of the film-forming range R. Therefore, the normal to the surface of the cooling surface 131 intersects the center of the film-forming range R.

[0038] Furthermore, a piping 132 for circulating refrigerant to control temperature is provided in the radiant cooling member 130. In this embodiment, a structure is adopted to control the temperature of the radiant cooling member 130 by circulating refrigerant in the piping 132. That is, the temperature of the radiant cooling member 130 can be controlled by changing the temperature of the refrigerant, changing the flow rate of the refrigerant, or a combination thereof. In film-forming apparatuses, cooling piping using refrigerants such as water is generally distributed near the film-forming source. If a branch of this piping is introduced into the radiant cooling member 130 as in this embodiment, a simple structure can be achieved. Of course, a dedicated cooling piping system can also be constructed, and since a more precise temperature control can be achieved, a dedicated cooling piping system is preferred. In addition, the structure for controlling the temperature of the radiant cooling member 130 is not limited to a structure using refrigerant. For example, a structure in which a Peltier element (not shown) for temperature control is provided in the radiant cooling member 130 can also be used.

[0039] As described above, the film-forming region R is the area heated by radiative heat from the film-forming source 110. Now, if we set the temperature of the film-forming region R as T1 (K), the surface temperature of the cooling surface 131 as T2 (K), and assume that T1 > T2, then we can set σ as the Stefan-Boltzmann constant of 5.67 × 10⁻⁶. －8 W / m 2 K 4The energy flow J (W / m) transferred from the film-forming range R to the cooling surface 131 2 )Depend on

[0040] J = σ × (T1) 4 -T2 4 )・・・Form 1

[0041] Determined. For simplicity, the emissivity is assumed to be 1, and the shape factor is ignored. By controlling the temperature of the radiative cooling member 130, an energy flow determined by Equation 1 is generated, absorbing energy radiatively from the film-forming region R, thereby reducing the temperature of the film-forming region R. Radiative heat energy from the film-forming source 110 flows into the film-forming region R, causing its temperature to rise, while radiative heat energy flows out from the film-forming region R to the radiative cooling member 130. Through the balance of this inflow and outflow, the temperature of the film-forming region R is determined.

[0042] To effectively cool the film-forming area R, as described above, a structure is adopted in which the normal of the surface of the cooling surface 131 intersects the center of the film-forming area R. Particularly preferred is that, as in this embodiment, the cooling surface 131 is composed of a hemispherical surface, with the center of the hemispherical surface located at the center of the film-forming area R. The reason for this will be explained. The heat energy emitted from the film-forming area R according to Equation 1 diffuses isotropically from the film-forming area R. If the cooling surface 131 is composed of a hemispherical surface, the heat energy can be captured without omission. Furthermore, the electromagnetic waves radiated from the film-forming area R (see...) Figure 3 The solid arrow in the image indicates that the electromagnetic wave is incident perpendicularly on the surface of the cooling surface 131. Therefore, even if there is a reflected component of the electromagnetic wave (see reference...), Figure 3 (As indicated by the dashed arrow in the image), the reflected component also returns to the emission point within the film formation area R. Therefore, there is no in-mask diffusion of heat energy due to multiple reflections, enabling efficient cooling.

[0043] Below, refer to Figure 4 The film formed on the cooling surface 131 will be described below. Even if the radiation cooling member 130 is positioned such as in this embodiment that it does not obstruct the path of the film-forming material from the film-forming source 110 to the film-forming range R of the substrate S, a film will still be formed on the cooling surface 131. This will be explained below.

[0044] In typical vacuum evaporation equipment or processes for organic EL and other materials, the pressure within the chamber during film formation (evaporation) is generally 10. －2 The mean free path λ (m) of the film-forming material particles (evaporated particles) under this condition is λ = (k × T) / (√2) × π × p × d 2 ).

[0045] Here, k = 1.38 × 10 －23(J / K) is Boltzmann's constant, T is the gas temperature (K), p is the gas pressure (Pa), and d is the diameter of the gas molecules (m). 2 Furthermore, mean free path refers to the average distance a gas molecule can travel in a straight line without colliding with other gas molecules. For example, if the pressure is set to 10... －2 Pa, with the diameter of gas molecules set at 3.5 × 10⁻⁶. －10 m 2 If the gas temperature is set to 300K, then λ is approximately 0.76m = 760mm, which is on the same order of magnitude as the distance from the film formation source 110 to the mask M and the substrate S. Therefore, as Figure 4 As shown by the solid arrows, the vapor-deposited particles emitted from the film-forming source 110 do not scatter even once and reach the mask M and substrate S in a straight line. However, as... Figure 4 As shown by the dashed arrows in the diagram, some particles will scatter midway and change their orbits with probability. Some of the scattered particles reach the cooling surface 131, which is located in the part that is obscured (the part that cannot be seen) when viewed from the film-forming source 110.

[0046] In a single vapor deposition process, very few scattered particles reach the cooling surface 131. However, in mass production and other situations where vapor deposition is performed continuously over a long period, the amount of film adhering to the cooling surface 131 by scattered particles accumulates and increases to a non-negligible level. Specifically, the amount of particles reaching the cooling surface 131 varies significantly depending on the structure of the apparatus, the pressure during vapor deposition, etc., and is therefore difficult to calculate. However, it can typically be assumed that the amount of particles reaching the mask M and the substrate S is approximately 0.1% to a few percent.

[0047] If a film of film-forming material is formed on the cooling surface 131, the cooling capacity will change due to variations in the film's absorption of electromagnetic waves, surface roughness, emissivity, etc. For example, it is known that Alq3, an organic material widely used in the vapor deposition of organic EL, absorbs electromagnetic waves in the near-infrared region at a rate of several percent at a film thickness of several tens of nm. This is a significant amount that can cause a change in cooling capacity and cannot be ignored in a mass production apparatus designed for continuous operation. Furthermore, the amount of film adhering to the cooling surface 131 (film thickness) does not necessarily increase constantly over time due to variations in production volume and sudden boiling during continuous operation. Therefore, in this embodiment, the following structure is adopted: the thickness of the film formed on the cooling surface 131 is measured by a film thickness gauge 140 disposed near the radiative cooling member 130, and the temperature of the radiative cooling member 130 is controlled by the control unit C to compensate for changes in cooling capacity. That is, in the film-forming apparatus 1 of this embodiment, the temperature of the radiative cooling member 130 is controlled based on the thickness of the film of film-forming material formed on the cooling surface 131. Furthermore, in this embodiment, the film thickness gauge 140 is configured such that the front end of the film thickness gauge 140 protrudes slightly from the opening 131b formed on the cooling surface 131.

[0048] In general vacuum evaporation apparatuses, such as organic EL evaporation apparatuses, crystal film thickness gauges, commonly used for rate control of the evaporation source, are preferred as film thickness gauges 140 because they can measure film thickness at the nanometer level with high precision and have a small measuring unit. However, in cases where it is difficult to install a crystal film thickness gauge due to design constraints, the thickness of the film formed on the cooling surface 131 can be set to be proportional to the evaporation time or the apparatus operating time, and temperature correction of the radiation cooling member 130 can be performed as a function of time. In this way, a structure can be adopted to derive the film thickness of the film-forming material formed on the cooling surface 131 using parameters including the measured film formation time.

[0049] It can be assumed that the relationship between the thickness (attached film amount) of the film formed on the cooling surface 131 and the change in the cooling capacity of the radiation cooling member 130 varies greatly depending on the material being deposited and the structure of the apparatus. Therefore, it is practical to confirm this relationship in advance through element experiments and save it in a table. That is, the control temperature of the radiation cooling member 130 in the state where no film is formed on the cooling surface 131 can be used as the reference temperature, and the amount of temperature reduction due to the thickness of the film formed on the cooling surface 131 can be set to be proportional to the Xth power of the film thickness. Furthermore, X is set according to the film forming material and film forming conditions. Typically, X can be set to one-quarter. This is because for organic films such as Alq3, if it is assumed that the absorption of electromagnetic waves increases linearly proportionally to the film thickness, then according to the Stefan-Boltzmann law of the fourth power of the temperature of the radiation energy, it can be considered that a correction such as reducing the temperature of the cooling surface 131 of the radiation cooling member 130 proportional to the 1 / 4 power of the film thickness can be made. This proportionality coefficient can be identified in advance through experiments.

[0050] As described above, the film-forming method using the film-forming apparatus 1 of this embodiment includes: a step of obtaining the thickness of the film of the film-forming material formed on the cooling surface 131 by the control unit C; and a step of controlling the temperature of the radiation cooling member 130 based on the obtained film thickness. Therefore, even if the thickness of the film formed on the cooling surface 131 increases over time, the cooling function can be maintained, and the mask M can be cooled stably. Thus, high film-forming accuracy can also be maintained.

[0051] In this embodiment, only one film thickness gauge 140 is provided, but a structure with multiple gauges can also be adopted. In this case, the thickness of the film formed at multiple locations on the cooling surface 131 is measured. Therefore, the temperature of the radiative cooling member 130 can be controlled at multiple locations, and the cooling function can be maintained more stably. In addition, it is also possible to perform control such as determining the temperature correction amount based on the average film thickness at each location.

[0052] Furthermore, in the case of a structure in which film deposition is performed on the entire substrate S while the film deposition unit 100 is moved, as in this embodiment, the temperature control amount of the radiative cooling member 130 can be controlled to vary according to the movement of the film deposition range R. For example, the temperature correction amount can be controlled to vary when film deposition is performed at the center of the substrate S and the mask M and when film deposition is performed at the end portions. This is because, for example, the heat released by the members supporting the substrate S and the mask M varies depending on these locations, and therefore, the appropriate correction amount for changing the temperature of the radiative cooling member 130 may change.

[0053] (Example 2)

[0054] exist Figure 5 Embodiment 2 of the present invention is shown. In Embodiment 1 above, a structure was shown in which a single radiative cooling member with a cooling surface composed of a hemispherical surface was provided. In contrast, in this embodiment, a structure was shown in which multiple radiative cooling members were provided. Other structures and functions are the same as in Embodiment 1; therefore, the same reference numerals are used to label the same components, and their descriptions are omitted.

[0055] Figure 5 This is a schematic structural diagram of the film-forming apparatus according to Embodiment 2 of the present invention. Figure 5 The internal structure of the device is shown in a schematic diagram, with a portion of the structure shown in a schematic cross-sectional view. The film-forming apparatus 1A in this embodiment also includes a chamber 10 and a film-forming unit 100A. Furthermore, the film-forming unit 100A includes a film-forming source 110, a confinement member 120, a radiation cooling member 130A, and a film thickness gauge 140.

[0056] In this embodiment, the difference from Embodiment 1 lies in the provision of multiple radiative cooling members 130A. Each radiative cooling member 130A, as in Embodiment 1, has a cooling surface 131A and a piping 132A for refrigerant circulation for temperature control. Furthermore, the multiple radiative cooling members 130A are arranged such that the normal to the surface of their respective cooling surface 131A intersects the center (near the center) of the film-forming range R. Moreover, the surface shape of the cooling surface 131A can be planar or curved, such as concave. That is, as described above, the shape of the surface is not limited if the normal to the surface of the cooling surface 131A intersects the center of the film-forming range R. By setting the tilt angle and surface shape of the cooling surface 131A according to the arrangement position of the radiative cooling members 130A, the normal to the surface of the cooling surface 131A can be made to intersect the center of the film-forming range R. By adopting the structure of this embodiment, compared to Embodiment 1, the height of the radiative cooling member 130A can be suppressed, thus increasing design freedom. It is particularly effective when the height of the radiative cooling component 130A is limited due to design constraints.

[0057] Furthermore, in this embodiment, a refrigerant is used as a structure for controlling the temperature of the radiative cooling member 130A. However, as explained in Embodiment 1, the structure for controlling the temperature is not limited, and a Peltier element can also be used, for example. Additionally, in this embodiment, the thickness of the film formed on the cooling surface 131A can be detected using a film thickness gauge 140, such as a crystal film thickness gauge. However, as explained in Embodiment 1, a structure can also be used to derive the thickness of the film formed on the cooling surface 131A using parameters including the measured film formation time. Furthermore, in this embodiment, by employing a structure with multiple film thickness gauges 140, the temperature of the radiative cooling member 130A can be controlled at multiple locations, or the temperature correction amount can be determined based on the average film thickness at each location. Moreover, in this embodiment, when a structure is used to form a film on the entire substrate S while moving the film forming unit 100A, the temperature control amount of the radiative cooling member 130A can be controlled to change according to the movement of the film forming range R.

[0058] <Methods for Manufacturing Electronic Devices>

[0059] 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, the structure and manufacturing method of an organic EL display device will be illustrated as an example of an electronic device. First, the organic EL display device to be manufactured will be described. Figure 6 (a) represents an overall view of the organic EL display device 560. Figure 6 (b) represents the cross-sectional structure of 1 pixel.

[0060] like Figure 6 As shown in (a), in the display area 561 of the organic EL display device 560, a plurality of pixels 562, each equipped with a plurality of light-emitting elements, are arranged in a matrix. Each light-emitting element has a structure having an organic layer sandwiched between a pair of electrodes, which will be described in detail later. Furthermore, the pixel referred to herein is the smallest unit capable of displaying a desired color in the display area 561. In the case of the organic EL display device of this embodiment, the pixel 562 is constituted 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. The pixel 562 is typically composed of a combination of red, green, and blue light-emitting elements, but it may 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.

[0061] Figure 6 (b) is Figure 6 A partial cross-sectional view along line A-B in (a). Pixel 562 has an organic EL element comprising 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 on a substrate 563. The hole transport layer 565, the light-emitting layers 566R, 566G, 566B, and the electron transport layer 567 are equivalent to organic layers. Furthermore, 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). Additionally, the first electrode 564 is formed separately for each light-emitting element. The hole transport layer 565, electron transport layer 567, and second electrode 568 can be formed commonly in multiple light-emitting elements 562R, 562G, and 562B, or they can be formed for each light-emitting element. Furthermore, to prevent short circuits between the first electrode 564 and the second electrode 568 due to foreign matter, an insulating layer 569 is provided between the first electrode 564. Also, since the organic EL layer is susceptible to degradation due to moisture or oxygen, a protective layer 570 is provided to protect the organic EL element from the effects of moisture or oxygen.

[0062] exist Figure 6In (b), the hole transport layer 565 and the electron transport layer 567 are represented as a single layer, but depending on the structure of the organic EL display element, they can also be formed from multiple layers including a hole blocking layer and an electron blocking layer. Alternatively, a hole injection layer with a band structure can be formed between the first electrode 564 and the hole transport layer 565 to allow holes to be smoothly injected from the first electrode 564 into 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.

[0063] The following is a detailed description of an example of a method for manufacturing an organic EL display device. First, a substrate 563 is prepared, which has a circuit (not shown) for driving the organic EL display device and a first electrode 564.

[0064] Acrylic resin is formed on substrate 563 where the first electrode 564 is formed by spin coating. The acrylic resin is then patterned using photolithography to form an opening in the portion where the first electrode 564 is formed, thereby forming an insulating layer 569. This opening corresponds to the light-emitting area where the light-emitting element actually emits light.

[0065] A substrate 563 with an insulating layer 569 patterned 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, therefore, a high-precision mask is not required.

[0066] Next, the substrate 563 to which the hole transport layer 565 is formed is fed into the second film-forming 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 where the red element is arranged.

[0067] Similar to the deposition of the light-emitting layer 566R, the green-emitting layer 566G is deposited using a third film deposition apparatus, and then the blue-emitting layer 566B is deposited using a fourth film deposition apparatus. After the deposition of the light-emitting layers 566R, 566G, and 566B is completed, the electron transport layer 567 is deposited over the entire display area 561 using a fifth film deposition apparatus. The electron transport layer 567 is formed as a common layer on the three-color light-emitting layers 566R, 566G, and 566B.

[0068] The substrate to which the electron transport layer 567 is formed is moved to a sputtering apparatus to form a film on the second electrode 568, and then moved to a plasma CVD apparatus to form a protective layer 570, thereby completing the organic EL display device 560.

[0069] From the moment the substrate 563 with the insulating layer 569 patterned is fed into the film-forming apparatus until the film-forming of the protective layer 570 is completed, if exposed to an environment containing moisture or oxygen, the light-emitting layer made of organic EL material may deteriorate due to moisture or oxygen. Therefore, in this example, the feeding and unloading of the substrate between the film-forming apparatuses is performed in a vacuum environment or an inactive gas environment.

[0070] Explanation of reference numerals in the attached figures

[0071] 1, 1A: Film forming apparatus; 10: Chamber; 20: Track; 100, 100A: Film forming unit; 110: Film forming source; 120: Restricting member; 121: Opening; 130, 130A: Radiation cooling member; 131, 131A: Cooling surface; 131a: Opening; 132, 132A: Piping; 140: Film thickness gauge; C: Control unit; M: Mask; R: Film forming range; S: Substrate.

Claims

1. A film-forming apparatus, wherein the film-forming apparatus forms a thin film on a substrate via a mask within a chamber using a film-forming material emitted from a film-forming source, characterized in that, The film-forming apparatus includes a radiation cooling member disposed at a position that does not obstruct the path of the film-forming material from the film-forming source to the film-forming area of ​​the substrate, and has a cooling surface capable of heat exchange via radiation. The temperature of the radiative cooling component is controlled based on the thickness of the film formed by the film-forming material on the cooling surface.

2. The film-forming apparatus according to claim 1, characterized in that, The cooling surface is configured such that the normal to its surface intersects the center of the film-forming area.

3. The film-forming apparatus according to claim 2, characterized in that, The cooling surface is composed of a hemispherical surface, and is configured such that the center of the hemispherical surface is located at the center of the film-forming area.

4. The film-forming apparatus according to claim 2, characterized in that, The radiation cooling components are provided in multiple ways, and the multiple radiation cooling components are configured such that the normal of the surface of their respective cooling surfaces intersects with the center of the film-forming range.

5. The film-forming apparatus according to claim 1, characterized in that, The radiant cooling component is provided with piping for the circulation of refrigerant for temperature control.

6. The film-forming apparatus according to claim 1, characterized in that, The radiative cooling component is equipped with a Peltier element for temperature control.

7. The film-forming apparatus according to claim 1, characterized in that, The film-forming apparatus includes a crystal film thickness gauge for measuring the thickness of the film formed on the cooling surface.

8. The film-forming apparatus according to claim 1, characterized in that, The thickness of the film formed on the cooling surface is derived using parameters including the measured film formation time.

9. The film-forming apparatus according to claim 1, characterized in that, The control temperature of the radiative cooling member in the state where no film is formed on the cooling surface is used as the reference temperature, and the amount of temperature reduction that is reduced according to the thickness of the film-forming material formed on the cooling surface is set to be proportional to the X-th power of the thickness of the film.

10. The film-forming apparatus according to claim 9, characterized in that, X is set according to the film-forming material and film-forming conditions.

11. The film-forming apparatus according to claim 1, characterized in that, The temperature of the radiative cooling member is controlled at each of the multiple locations based on the thickness of the film formed by the film-forming material at each of the multiple locations on the cooling surface.

12. The film-forming apparatus according to claim 1, characterized in that, The temperature control amount of the radiative cooling component changes according to the movement of the film-forming range.

13. A film-forming method, wherein a thin film is formed on a substrate in a chamber by means of a film-forming material emitted from a film-forming source via a mask, characterized in that, A radiation cooling member having a cooling surface capable of heat exchange via radiation is provided at a position that does not obstruct the path of the film-forming material from the film-forming source to the film-forming area of ​​the substrate. The film-forming method includes: The process of obtaining the thickness of the film formed on the cooling surface; and The process of controlling the temperature of the radiative cooling component based on the obtained thickness of the film.

14. A method for manufacturing an electronic device, characterized in that, Electronic devices are manufactured using the film-forming method of claim 13.

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