Evaporation source, film deposition apparatus and method for depositing film

Abstract

To provide an evaporation source that can suppress variation in film deposition characteristics, and to provide a film deposition apparatus and a method for depositing a film.SOLUTION: An evaporation source 300 for depositing a film while moving relatively to a substrate includes: a nozzle 332 for jetting a material that is evaporated or sublimated by heating a film deposition material M stored in a material container; and a cylindrical member 333 disposed so as to surround an outer periphery of the nozzle 332.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an evaporation source, a film forming apparatus, and a film forming method. [Background technology]

[0002] In a film forming apparatus for forming a thin film on a substrate, a technique is known in which a film forming material is ejected from multiple nozzles while moving an evaporation source to form a film. This technique can be used to form a thin film suitably even on a large-sized substrate. Patent Document 1 discloses a technique in which a protruding reflector is provided on multiple evaporation source nozzles and arranged on a part of the outer side of the multiple evaporation source nozzles to suppress a temperature drop in the multiple nozzles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-146658 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configuration of Patent Document 1 cannot sufficiently suppress the temperature drop of the nozzle, and the drop in the nozzle temperature makes it easier for material to accumulate in the nozzle, which can result in variation in the film formation characteristics. An object of the present invention is to provide an evaporation source, a film formation apparatus, and a film formation method that can suppress the variation in the film formation characteristics. [Means for solving the problem]

[0005] The present invention employs the following means to solve the above problems.

[0006] That is, the evaporation source of the present invention is An evaporation source that forms a film while moving relative to a substrate, a nozzle for ejecting a film forming material that is evaporated or sublimated by heating the film forming material contained in a material container; A cylindrical member disposed so as to surround an outer periphery of the nozzle; The present invention is characterized by comprising: Effect of the Invention

[0007] As described above, according to the present invention, it is possible to suppress variations in film formation characteristics. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a film forming apparatus according to an embodiment of the present invention. [Diagram 2] 1 is a schematic configuration diagram of a film forming apparatus according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic cross-sectional view of an evaporation source according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic cross-sectional view of an evaporation source according to an embodiment of the present invention. [Diagram 5] 11A and 11B are explanatory diagrams of a modified example of an evaporation source according to an embodiment of the present invention. [Figure 6] 1A to 1C are explanatory diagrams of a method for manufacturing an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, with reference to the drawings, an embodiment of the present invention will be described in detail. However, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in the embodiment are not intended to limit the scope of the present invention. In the following description, the direction of movement of the evaporation source is defined as a first direction X, A direction intersecting the first direction X is defined as a second direction Y. More specifically, in each embodiment, the second direction Y is a direction perpendicular to the first direction X and parallel to the deposition surface of the substrate on which the film is deposited.

[0010] (Example) An evaporation source according to an embodiment of the present invention, a film formation apparatus including the evaporation source, and a film formation method using the evaporation source will be described with reference to FIGS.

[0011] <Film forming equipment> A film forming apparatus 10 according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram of the film forming apparatus according to this embodiment of the present invention, and shows a simplified configuration as seen from the front side. Figure 2 is a schematic diagram of the film forming apparatus according to this embodiment of the present invention, and shows a simplified configuration as seen from above. Note that in Figures 1 and 2, the main components are shown in perspective.

[0012] The film forming apparatus 10 according to this embodiment is a deposition apparatus that performs vacuum deposition. The film forming apparatus 10 includes a chamber 100, a vacuum pump 200 for creating a vacuum (reduced pressure atmosphere) inside the chamber 100, and an evaporation source 300 disposed inside the chamber 100. The evaporation source 300 serves to evaporate or sublimate a film forming material M to be deposited on a substrate S disposed inside the chamber 100 by heating the material. The material evaporated or sublimated by the evaporation source 300 adheres to the substrate S, forming a thin film on the substrate S.

[0013] The film forming apparatus 10 also includes an atmosphere box 410 for supplying electricity and a cooling liquid to the evaporation source 300, and a first atmosphere arm 420 and a second atmosphere arm 430 that move in accordance with the movement of the atmosphere box 410. The atmosphere box 410 is hollow and communicates with the outside of the chamber 100 through the insides of the first atmosphere arm 420 and the second atmosphere arm 430. Therefore, the inside of the atmosphere box 410 is exposed to the atmosphere. By adopting such a configuration, wiring connected to a power source provided outside the chamber 100 and a cooling pipe connected to a cooling liquid supply device provided outside the chamber 100 can be connected to the evaporation source 300.

[0014] The first atmospheric arm 420 and the second atmospheric arm 430 are provided to arrange wiring and cooling pipes in the cavity of the moving atmospheric box 410. That is, the first atmospheric arm 420 and the second atmospheric arm 430 are configured to have a hollow interior and to move following the movement of the atmospheric box 410. More specifically, one end of the second atmospheric arm 430 is configured to be rotatable with respect to the bottom plate of the chamber 100. One end of the first atmospheric arm 420 is rotatably supported with respect to the other end of the second atmospheric arm 430, and the other end is rotatably supported with respect to the atmospheric box 410.

[0015] The film forming apparatus 10 is also provided with a moving mechanism for moving the evaporation source 300. The moving mechanism according to this embodiment includes a pair of guide rails 520, a pair of gears 510 provided on both sides of a rotation shaft penetrating the atmospheric box 410, and a driving source (not shown) such as a motor for rotating the rotation shaft. The pair of guide rails 520 are provided with racks that mesh with the pair of gears 510, respectively. With the above configuration, the evaporation source 300 can be reciprocated together with the atmospheric box 410 along the pair of guide rails 520 by rotating the rotation shaft with the driving source.

[0016] As described above, the evaporation source 300 is configured to be guided by the pair of guide rails 520 and to move linearly back and forth in the first direction X. Then, the deposition material M is evaporated or sublimated while the evaporation source 300 is moved in the first direction X, so that the deposition material M is deposited on the substrate S. A thin film can be formed. The film can be formed during at least one of the forward and backward movements of the evaporation source 300. In this manner, the film is formed while the evaporation source 300 moves relatively to the substrate S.

[0017] As described above, the moving mechanism in this embodiment employs a so-called rack and pinion mechanism. However, the moving mechanism for reciprocating the atmospheric box 410 and the evaporation source 300 is not limited to the rack and pinion mechanism, and various known techniques such as a ball screw mechanism may be employed.

[0018] In the film forming apparatus 10 according to this embodiment, a film thickness monitor 600 for measuring the film thickness of a film formed on the substrate S is provided on each side of the evaporation source 300 in the second direction Y. The film thickness monitor 600 measures the film thickness of a film formed on the substrate S by measuring the film thickness of the film formed on the film thickness monitor 600 and predicting the film thickness of the film formed on the substrate S based on the measured film thickness. By controlling the amount of film formation (for example, by controlling the amount of heat applied to the film forming material M in the evaporation source 300) based on the film thickness measured by the film thickness monitor 600, the thickness of the thin film formed on the substrate S can be adjusted to a desired thickness.

[0019] <Evaporation source> An evaporation source 300 according to an embodiment of the present invention will be described with reference to Fig. 3 and Fig. 4. Fig. 3 and Fig. 4 are schematic cross-sectional views of an evaporation source according to an embodiment of the present invention. Fig. 3 is a simplified cross-sectional view of the evaporation source 300 cut along a plane perpendicular to the second direction Y and passing through the nozzle center, and Fig. 4 is a simplified cross-sectional view of the evaporation source 300 cut along a plane parallel to the first direction X and passing through the nozzle center. Note that a large number of nozzles are provided (Figs. 1 and 2 show a case where 14 nozzles are provided), but Fig. 4 shows only four nozzles for convenience.

[0020] The evaporation source 300 includes a rectangular parallelepiped case. This case includes a case body 311 having a bottom plate portion and four side plate portions, and a lid portion 312 that covers most of the upper opening of the case body 311. The case body 311 has a heat insulating function. For example, a passage (flow path) is formed inside the case body 311, and a cooling liquid such as cooling water is caused to flow through this passage, thereby achieving a heat insulating effect.

[0021] The evaporation source 300 also includes a material container (crucible) provided in a case. The material container includes a lower crucible 320 forming a material chamber 321 and an upper crucible 330 forming a diffusion chamber 331. A plurality of nozzles 332 are provided on the upper surface of the upper crucible 330. The lower crucible 320 and the upper crucible 330 are fixed by a fixing device B such as a bolt with a middle plate 340 having an introduction pipe 341 for communicating the material chamber 321 and the diffusion chamber 331 sandwiched between them. The material chamber 321 is a chamber used to contain the film forming material M. The diffusion chamber 331 is a chamber for diffusing the material evaporated or sublimated by heating the film forming material contained in the material chamber 321 before it reaches the plurality of nozzles 332 to adjust the pressure distribution and adjust the inflow amount to the plurality of nozzles 332. The material evaporated or sublimated inside the material chamber 321 is introduced into the diffusion chamber 331 through an inlet pipe 341, where it is diffused and ejected into the chamber 100 from a plurality of nozzles 332. The material container configured as described above is supported by a support member 350, and is fixed to the case while being positioned within the case.

[0022] The evaporation source 300 also includes a first heater 361 for heating the lower crucible 320 and a second heater 362 for heating the upper crucible 330. The first heater 361 is provided between the outer wall surface of the lower crucible 320 and the inner wall surface of the case body 311, and the second heater 362 is provided between the outer wall surface of the upper crucible 330 and the inner wall surface of the case body 311. A first heater 361 and a second heater 362 are provided on the front side and the back side of the drawing, respectively, though not shown. That is, the first heater 361 and the second heater 362 are provided so as to surround the outer wall surfaces of the lower crucible 320 and the upper crucible 330, respectively. As the first heater 361 and the second heater 362, a member that generates heat when electricity is applied, such as a sheath heater, can be suitably used. The first heater 361 heats the film forming material M contained in the lower crucible 320, and the film forming material M evaporates or sublimates. In addition, the second heater 362 can prevent the evaporated or sublimated material from solidifying in the diffusion chamber 331 of the upper crucible 330.

[0023] Furthermore, in the evaporation source 300, reflectors 371, 372, 373, and 374 are provided between the bottom surface of the case body 311 and the material container, between the lower surface of the lid part 312 and the material container, between the first heater 361 and the second heater 362, and between the inner wall surface of the case body 311 and the material container, respectively. These reflectors 371, 372, 373, and 374 can suppress the heat from the first heater 361 and the second heater 362 from being transmitted to the case, so that the material chamber 321 and the diffusion chamber 331 can be efficiently heated and the heat can be suppressed from escaping to the outside of the case. Note that the heating efficiency can be further improved by adopting a configuration in which a plurality of reflectors are arranged side by side between the case body 311 and various members.

[0024] <Details of the nozzle area> A detailed configuration of the vicinity of the nozzle 332 will be described. The evaporation source 300 according to this embodiment includes a plurality of cylindrical members 333 arranged so as to surround the outer circumference of each of the nozzles 332. In FIG. 4, a part of a plan view of the vicinity of the nozzle 332 seen from above is shown at the top of the cross-sectional view. As shown in this figure, in this embodiment, the cylindrical member 333 has a cylindrical shape, but the shape is not limited as long as it is cylindrical. These multiple cylindrical members 333 are fixed to the material container (more specifically, the upper crucible 330) and are integrally provided with the material container. Note that the lid portion 312 has through holes 312a at positions where the multiple nozzles 332 and the cylindrical members 333 are provided. As a result, the nozzles 332 and the cylindrical members 333 are configured to pass through the through holes 312a and have their tips protrude above the upper surface of the lid portion 312.

[0025] Also, as shown in FIG. 5(a)(b), a configuration can be adopted in which a reflector 372 arranged between the lower surface of the lid portion 312 and the material container is provided with a protruding portion 372a that protrudes upward so as to face the outer wall surface of the cylindrical member 333. In this illustrated example, a configuration is adopted in which the protruding portion 372a is arranged to surround the cylindrical member 333. More specifically, the shape of the protruding portion 372a is cylindrical. However, it is sufficient for the protruding portion 372a to exhibit a heat insulating function, and it is not necessarily required that the protruding portion 372a surrounds the cylindrical member 333. Also, in the example shown in FIG. 5(a)(b), the protruding portion 372a is configured to surround one cylindrical member 333. However, when the interval between the adjacent nozzles 332 and cylindrical members 333 is narrow, a configuration can be adopted in which one protruding portion 372a surrounds multiple cylindrical members 333. FIG. 5(c) shows a configuration in which one protrusion 372a surrounds two tubular members 333, but it is also possible to adopt a configuration in which one protrusion 372a surrounds three or more tubular members 333.

[0026] <Electronic device manufacturing method> Next, an example of a method for manufacturing an electronic device using the evaporation source, the film forming apparatus, and the film forming method according to the present embodiment will be described. Below, the configuration of an organic EL display device will be shown as an example of the electronic device, and a method for manufacturing the organic EL display device will be illustrated.

[0027] First, the organic EL display device to be manufactured will be described. FIG. 6(a) shows the organic EL display device 1. FIG. 6(b) shows the overall structure of the pixel 50 and the cross-sectional structure of one pixel.

[0028] As shown in FIG. 6(a), a plurality of pixels 152 each including a plurality of light-emitting elements are arranged in a matrix in a display region 151 of an organic EL display device 150. Although details will be described later, each light-emitting element has a structure including an organic layer sandwiched between a pair of electrodes. Note that the pixel here refers to the smallest unit that allows a desired color to be displayed in the display region 151. In the case of the organic EL display device according to this embodiment, the pixel 152 is configured by a combination of a first light-emitting element 152R, a second light-emitting element 152G, and a third light-emitting element 152B that emit light different from each other. The pixel 152 is often configured by a combination of a red light-emitting element, a green light-emitting element, and a blue light-emitting element, but may also be a combination of a yellow light-emitting element, a cyan light-emitting element, and a white light-emitting element, and is not particularly limited as long as it is at least one color.

[0029] Fig. 6(b) is a schematic partial cross-sectional view taken along line AB in Fig. 6(a). The pixel 152 is made up of a plurality of light-emitting elements, and each light-emitting element has a first electrode (anode) 154, a hole transport layer 155, any one of light-emitting layers 156R, 156G, and 156B, an electron transport layer 157, and a second electrode (cathode) 158 on a substrate 153. Among these, the hole transport layer 155, the light-emitting layers 156R, 156G, and 156B, and the electron transport layer 157 correspond to organic layers. In this embodiment, the light-emitting layer 156R is an organic EL layer that emits red light, the light-emitting layer 156G is an organic EL layer that emits green light, and the light-emitting layer 156B is an organic EL layer that emits blue light. The light-emitting layers 156R, 156G, and 156B are formed in patterns corresponding to light-emitting elements (sometimes referred to as organic EL elements) that emit red, green, and blue light, respectively. In addition, the first electrode 154 is formed separately for each light-emitting element. The hole transport layer 155, the electron transport layer 157, and the second electrode 158 may be formed in common for the plurality of light-emitting elements 152R, 152G, and 152B, or may be formed for each light-emitting element. In order to prevent the first electrode 154 and the second electrode 158 from being shorted by foreign matter, an insulating layer 159 is provided between the first electrodes 154. Furthermore, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 140 is provided to protect the organic EL element from moisture and oxygen.

[0030] 6(b), the hole transport layer 155 and the electron transport layer 157 are shown as single layers, but depending on the structure of the organic EL display element, they may be formed of multiple layers including a hole blocking layer and an electron blocking layer. In addition, a hole injection layer having an energy band structure that can smoothly inject holes from the first electrode 154 to the hole transport layer 155 can be formed between the first electrode 154 and the hole transport layer 155. Similarly, an electron injection layer can be formed between the second electrode 158 and the electron transport layer 157.

[0031] Next, an example of a method for manufacturing an organic EL display device will be specifically described.

[0032] First, a substrate 153 on which a circuit (not shown) for driving the organic EL display device and a first electrode 154 are formed is prepared.

[0033] An acrylic resin is formed by spin coating on the substrate 153 on which the first electrode 154 is formed, and the acrylic resin is patterned by lithography so as to form an opening in the portion where the first electrode 154 is formed, thereby forming an insulating layer 159. This opening corresponds to the light-emitting region where the light-emitting element actually emits light.

[0034] The substrate 153 with the patterned insulating layer 159 is carried into a first organic material film forming apparatus, and the substrate is held by a substrate support table and an electrostatic chuck, and a hole transport layer 155 is formed as a common layer on the first electrode 154 in the display region. The hole transport layer 155 is formed by vacuum deposition. In practice, the hole transport layer 155 is formed to be larger than the display region 151, so no high-resolution mask is required.

[0035] Next, the substrate 153 on which the hole transport layer 155 has been formed is carried into a second organic material deposition apparatus and held by a substrate support table and an electrostatic chuck. The substrate and a mask are aligned, and the substrate is placed on the mask. A red light emitting layer 156R is deposited on the portion of the substrate 153 where a red light emitting element is to be disposed.

[0036] Similar to the formation of the light-emitting layer 156R, a third organic material film formation apparatus is used to form a green light-emitting layer 156G, and a fourth organic material film formation apparatus is used to form a blue light-emitting layer 156B. After the formation of the light-emitting layers 156R, 156G, and 156B is completed, a fifth film formation apparatus is used to form an electron transport layer 157 over the entire display area 151. The electron transport layer 157 is formed as a layer common to the three light-emitting layers 156R, 156G, and 156B.

[0037] The substrate on which the electron transport layer 157 has been formed is moved in a metallic evaporation material deposition apparatus, and a second electrode 158 is deposited.

[0038] Thereafter, the substrate is transferred to a plasma CVD apparatus, where a protective layer 140 is formed, and the organic EL display device 150 is completed.

[0039] If the substrate 153 on which the insulating layer 159 is patterned is exposed to an atmosphere containing moisture or oxygen from the time when it is carried into the film forming apparatus until the film formation of the protective layer 140 is completed, the light emitting layer made of an organic EL material may be deteriorated by moisture or oxygen. Therefore, in this embodiment, the substrate is carried in and out of the film forming apparatus in a vacuum atmosphere or an inert gas atmosphere.

[0040] <Advantages of the evaporation source, film forming apparatus, and film forming method according to the present embodiment> The evaporation source 300 according to this embodiment includes a plurality of cylindrical members 333 arranged to surround the outer circumference of each of the nozzles 332. This makes it possible to suppress a temperature drop in the nozzles 332 and to suppress variations in the film formation characteristics. In particular, since a temperature drop at the tip of the nozzle 332 is suppressed, it is possible to suppress deposition of material at the tip of the nozzle 332. Furthermore, since a temperature drop is suppressed even in the nozzles 332 near the end where the temperature is likely to drop, among the plurality of nozzles 332, it is possible to suppress variations in the temperature of each nozzle 332. Therefore, even if it becomes necessary to increase the longitudinal length of the evaporation source 300 as the substrate S on which the film is formed becomes larger, it is possible to suppress variations in the film formation characteristics.

[0041] For example, in the case of a large-sized substrate S with a width of 1,310 mm in the X direction and a width of 2,290 mm in the Y direction, the size of the evaporation source 300 is about 850 mm in the X direction width W1 and about 2,600 mm in the Y direction width W2. Even with such a large-sized evaporation source 300, it is possible to suppress the temperature drop of the nozzle 332 near the end in the Y direction, and to suppress the variation in the film formation characteristics. In addition, an experiment was conducted to compare the maximum and minimum temperatures of the multiple nozzles 332 in an evaporation source without a cylindrical member 333 and an evaporation source 300 with a cylindrical member 333 when heating was performed by supplying 500 W of power to the first heater 361 and 600 W of power to the second heater 362. As a result, the temperature difference in the former was 52° C., while the temperature difference in the latter was 37° C. It was thus confirmed that the evaporation source 300 according to this embodiment can suppress the temperature difference in the multiple nozzles 332.

[0042] Furthermore, as described with reference to FIG. 5, by adopting a configuration in which the reflector 372 is provided with a protruding portion 372a that protrudes upward so as to face the outer wall surface of the cylindrical member 333, the temperature drop of the nozzle 332 can be further suppressed.

[0043] 4 and 5, the nozzle 332 is shown extending straight in the vertical direction. However, the direction in which the nozzles 332 extend is not limited. For example, it is also possible to adopt a configuration in which the outer nozzles 332 among the multiple nozzles 332 are provided so as to be inclined outward with respect to the vertical direction. In this case, it is preferable to configure the cylindrical member 333 and the protruding portion 372a so as to be inclined outward with respect to the vertical direction as well (see FIG. 1). [Explanation of symbols]

[0044] 10: Film forming apparatus 100: Chamber 200: Vacuum pump 300: Evaporation source 311: Case body 312: Lid 312a: Through hole 320: Lower crucible 321: Material chamber 330: Upper crucible 331: Diffusion chamber 332: Nozzle 333: Cylindrical member 340: Middle plate 341: Introduction tube 350: Support member 361: First heater 362: Second heater 371, 372, 373, 374: Reflector 372a: Protrusion 410: Atmospheric box 420: First atmospheric arm 430: Second atmospheric arm 510: Gear 520: Guide rail 600: Film thickness monitor B: Fixture M: Film forming material S: Substrate

Claims

1. An evaporation source that forms a film while moving relatively to a substrate, a nozzle for ejecting a film forming material vaporized or sublimated by heating the film forming material contained in a material container; a cylindrical member disposed to surround the outer periphery of the nozzle to suppress a temperature drop of the nozzle; An evaporation source comprising:

2. An evaporation source that forms a film while moving relatively to a substrate, a plurality of nozzles for ejecting the film forming material vaporized or sublimated by heating the film forming material contained in the material container; a plurality of cylindrical members arranged to surround the outer peripheries of the plurality of nozzles, respectively; An evaporation source comprising:

3. 3. The evaporation source according to claim 1, wherein the cylindrical member is provided integrally with the material container.

4. a case for accommodating the material container; a reflector disposed between the case and the material container; Equipped with 4. The evaporation source according to claim 3, wherein the reflector has a protruding portion that protrudes upward so as to face the outer wall surface of the cylindrical member.

5. The evaporation source according to claim 4 , wherein the protrusion is disposed so as to surround the cylindrical member.

6. The material container includes: a material chamber that contains the film forming material; a diffusion chamber communicating with the material chamber, for diffusing the evaporated or sublimated film forming material contained in the material chamber by heating the film forming material; and 3. The evaporation source according to claim 1, wherein the nozzle is provided on an upper surface of the diffusion chamber.

7. a chamber; The evaporation source according to claim 1 or 2, which is disposed in the chamber; a moving mechanism for moving the evaporation source; A film forming apparatus comprising:

8. a step of moving the evaporation source according to claim 1 or 2; a step of ejecting the material evaporated or sublimated by the evaporation source while moving the evaporation source; A film forming method comprising the steps of:

Images