US20020011205A1 - Film-forming apparatus, method of cleaning the same, and method of manufacturing a light-emitting device - Google Patents

Abstract

A cleaning method of removing a vapor-deposition material adhering to equipments without exposure to the atmosphere is provided. A vapor-deposition material adhering to equipments (components of a film-forming apparatus) such as a substrate holder, a vapor-deposition mask, a mask holder, or an adhesion preventing shield provided in a film-forming chamber are subjected to heat treatment. Because of this, the adhering vapor-deposition material is re-sublimated, and removed by exhaust through a vacuum pump. By including such a cleaning method in the steps of manufacturing an electro-optical device, the manufacturing steps are shortened, and an electro-optical device with high reliability can be realized.

Description

TECHNICAL FIELD TO WHICH THE INVENTION BELONGS
• The present invention relates to a film-forming apparatus used for forming a film of a material (hereinafter, referred to as a “vapor-deposition material”) that can be formed into a film by vapor deposition, a method of cleaning the same, and a method of manufacturing an electro-optical device using the cleaning method. In particular, the present invention is a technique effective in the case of using an organic material as a vapor-deposition material.[0001]
• In the present specification, an electro-optical device intends to include a solar battery, a CCD (charge coupled device), a CMOS sensor, a liquid crystal display apparatus, an EL display apparatus, or a light source including an EL element (these will be collectively referred to as a “light-emitting device”).[0002]
PRIOR ART
• In recent years, a light-emitting element (hereinafter, referred to as an “EL element”) using an electro luminescent material (hereinafter, referred to as an “EL material”) that can obtain EL (electro luminescence) is being rapidly developed. In particular, an organic type EL material (hereinafter, referred to as an “organic EL material”) allows an EL element with a low driving voltage to be manufactured, so that such a material is expected to be applied to the next generation display.[0003]
• Note that, in the present specification, an EL element refers to a light-emitting element having a structure in which a layer (hereinafter, referred to as an “EL layer”) containing an EL material and an organic material or an inorganic material for injecting carriers into the EL material is interposed between two electrodes (positive electrode and negative electrode), i.e., a diode composed of a positive electrode, a negative electrode, and an EL layer.[0004]
• An EL element using an organic EL material generally utilizes an EL layer composed of a combination of an organic EL material and an organic material. The organic EL material and the organic material are roughly classified into a low-molecular type (monomer type) material and a high-molecular type (polymer type) material. Among them, a low-molecular type material is mainly formed into a film by vapor deposition.[0005]
• The organic EL material is very likely to degrade, and is easily oxidized in the presence of oxygen or water to degrade. Therefore, the organic EL material cannot be subjected to photolithography after being formed into a film. In order to pattern the film, it is required to isolate it simultaneously with the formation thereof, using a mask (hereinafter, referred to as a “vapor-deposition mask”) having an opening. Accordingly, most of the sublimated organic EL material adheres to a vapor-deposition mask or an adhesion preventing shield (protective plate for preventing a vapor-deposition material from adhering to an inner wall of a film-forming chamber) in a film-forming chamber.[0006]
• In order to remove an organic EL material adhering to the vapor-deposition mask or the adhesion preventing shield, it is required to once expose the film-forming chamber to the atmosphere, take the vapor-deposition mask and the adhesion preventing shield out of the chamber, clean them, and return them into the film-forming chamber. However, there is a concern that water or oxygen adsorbed to the vapor-deposition mask and the adhesion preventing shield exposed to the atmosphere may be desorbed during the formation of a film of the organic EL material and taken into the film, which can be a factor for promoting degradation of the organic EL material.[0007]
• In this case, by conducting vacuum heating under the condition that the vapor-deposition mask and the adhesion preventing shield are set, it is possible to remove adsorbed water or oxygen to some degree. However, vacuum heating for a long period of time causes a decrease in throughput.[0008]
SUMMARY OF THE INVENTION
• An object of the present invention is to provide a cleaning method of removing a vapor-deposition material adhering to equipments or an inner wall of a film-forming chamber to which the vapor-deposition material may adhere without exposure to the atmosphere, a film-forming apparatus equipped with a mechanism for conducting the cleaning method, and a method of manufacturing an electro-optical device including the cleaning method. In the present specification, equipments (components of a film-forming apparatus) provided in the film-forming apparatus include a substrate holder, a mask holder, an adhesion preventing shield, or a vapor-deposition mask.[0009]
• The present invention is characterized in that a vapor-deposition material adhering to equipments provided in a film-forming apparatus or an inner wall of the film-forming apparatus is sublimated again by heating, and the re-sublimated vapor-deposition material is exhausted through a vacuum pump. As heating means, a method of heating with radiation heat, a method of heating with infrared light, or a method of heating with UV-light can be used. The method of heating with radiation heat may also be specifically referred to as a method of heating with an electric heating wire (metal line with a high electric resistance).[0010]
• Note that it is also preferable that when the vapor-deposition material adhering to the equipments or the like is sublimated again, gas highly reactive to the vapor-deposition material is flowed in the film-forming chamber, whereby the re-sublimated vapor-deposition material is prevented from adhering to the equipments or the like again. More specifically, gas containing a halogen-group element (fluorine, chlorine, bromine, or iodine) may be flowed. Further, it is also effective to heat the entire portion that comes into contact with the vapor-deposition material to prevent the vapor-deposition material from adhering to the equipments or the like again. At this time, the portion may be typically heated with radiation heat.[0011]
• Further, in the present specification, sublimating again a vapor-deposition material adhering to a vapor-deposition mask or an inner wall of a film-forming chamber by heating is referred to as “re-sublimation”, and a vapor-deposition material that is sublimated again is referred to as a re-sublimated vapor-deposition material.[0012]
DESCRIPTION OF THE DRAWINGS
• [FIGS.[0013]1A-1C] Views showing cross-sectional structures of a film-forming chamber according to the present invention.
• [FIGS.[0014]2A-2B] Views showing cross-sectional structures of a film-forming chamber of Embodiment 1.
• [FIGS.[0015]3A-3B] Views showing structures of a vapor-deposition source and a vapor-deposition source holder of Embodiment 1.
• [FIG. 4] A view showing a structure of an upper surface of the film-forming chamber of Embodiment 1.[0016]
• [FIGS.[0017]5A-5B] Views showing cross-sectional structures of a film-forming chamber of Embodiment 2.
• [FIG. 6] A view showing a structure of an upper surface of the film-forming chamber of Embodiment 2.[0018]
• [FIG. 7] A view showing cross-sectional structures of a film-forming chamber of Embodiment 3.[0019]
• [FIG. 8] A view showing a structure of a film-forming apparatus of a multi-chamber system of[0020]Embodiment 5.
• [FIG. 9] A view showing a structure of a film-forming apparatus of an in-line system of Embodiment 6.[0021]
• [FIGS.[0022]10A-10B] Flow charts showing the steps of manufacturing a light-emitting device of Embodiment 7.
• [FIGS.[0023]11A-11B] Views showing the steps of manufacturing a light-emitting device of Embodiment8.
• [FIGS.[0024]12A-12C] Views showing the steps of manufacturing a light-emitting device of Embodiment 9.
• [FIGS.[0025]13A-13C] Views showing the steps of manufacturing a light-emitting device ofEmbodiment 10.
EMBODIMENTS
• A film-forming chamber of a film-forming apparatus for carrying out the present invention will be described with reference to FIG. 1. First, FIG. 1A shows a film-forming process using a vapor-deposition material. In a film-forming[0026]chamber101, asubstrate103 is disposed by asubstrate holder102. Thesubstrate103 intends to include a state in which a thin film is provided on a substrate surface.
• That is, a substrate in the process of forming a device is also included.[0027]
• Further, a vapor-[0028]deposition mask104 is provided in the vicinity of thesubstrate103, and the vapor-deposition mask104 is supported by amask holder105. Further, anadhesion preventing shield106 is provided on an inner side of an inner wall of the film-formingchamber101 so that a vapor-deposition material will not adhere to the inner wall of the film-formingchamber101.
• In this state, vapor-[0029]deposition sources108 provided at a vapor-deposition source holder107 are moved in a direction indicated by an arrow in the figure, whereby a vapor-deposition material109 sublimated from the vapor-deposition sources108 is formed into a film on thesubstrate103. A vapor-deposition shield110 is a shield for covering the vapor-deposition sources108 until sublimation from the vapor-deposition sources108 is stabilized.
• Further, although not shown, the vapor-[0030]deposition source holder107 is a holder in a rectangular shape that extends in a direction vertical to the drawing surface. On the vapor-deposition source holder107, a plurality of vapor-deposition sources108 are arranged.
• Herein, the[0031]substrate holder102, the vapor-deposition mask104, themask holder105, theadhesion preventing shield106, and thevapor deposition shield110 are disposed in the film-forming chamber, and they are equipments to which the vapor-deposition material109 adheres. According to the present invention, in order to heat the vapor-deposition material adhering to these equipments, it is preferable to use a material with high heat resistance as a material for the equipments.
• More specifically, metal with a high melting point such as tungsten, tantalum, titanium, chromium, nickel, and molybdenum, or an alloy containing these elements may be used. Further, metal such as stainless steel, Inconel, and Hastelloy may also be used. Further, a chromium oxide film or a tantalum oxide film may be provided on the surface of these metals as a protective film.[0032]
• Note that, in the case where gas is flowed in the film-forming chamber when the vapor-deposition material is re-sublimated, it is required to use metal with corrosion resistance to the gas.[0033]
• Next, FIG. 1B shows a state of the film-forming[0034]chamber101 after the film-forming process shown in FIG. 1A is repeated a plurality of times. FIG. 1B shows a state after thesubstrate103 is taken out of the film-forming chamber. In this state, the vapor-deposition material adheres to thesubstrate holder102, the vapor-deposition mask104, themask holder105, theadhesion preventing shield106, and the vapor-deposition shield110 by repeated vapor deposition. FIG. 1B shows an adhering vapor-deposition material111 by a dotted line.
• Next, FIG. 1C shows a process (cleaning process) of re-sublimation and exhaust. Herein, the vapor-[0035]deposition material111 adhering to thesubstrate holder102, the vapor-deposition mask104, themask holder105, theadhesion preventing shield106, and the vapor-deposition shield110 is heated and re-sublimated, thereby being desorbed from the equipments again. As a heating method, heating with a heater, heating with infrared light, or heating with UV-light may be used, or a combination thereof may be used.
• A vapor-[0036]deposition material112 thus re-sublimated is immediately exhausted through anexhaust port113 by using a vacuum pump (not shown). As a vacuum pump, any known pump may be used.
• Further, gas containing a halogen-group element may be flowed in the film-forming[0037]chamber101 when the process of re-sublimation and exhaust shown in FIG. 1C is conducted. Herein, re-sublimation is conducted while gas containing fluorine is flowed, and simultaneously, the vapor-deposition material is exhausted as fluoride.
• According to a series of processes described with reference to FIGS.[0038]1A-1C, a cleaning process is conducted after a film-forming process is conducted a plurality of times. However, a cleaning process can also be conducted for each film-forming process.
Embodiment 1
• In this embodiment, a method of cleaning a film-forming apparatus will be described, which is characterized in that equipments provided in a film-forming apparatus are irradiated with infrared light, UV-light, or visible light to sublimate a vapor-deposition material adhering to the equipments, and the sublimated vapor-deposition material is exhausted. The present example is one example of the present invention, and can cite the above description.[0039]
• FIGS.[0040]2A-2B show cross-sectional structures of a film-forming portion in a film-forming apparatus of this embodiment. FIGS. 2A and 2B show cross-sectional structures taken in directions vertical to each other. FIG. 2A shows a cross-section in an X-direction, and FIG. 2B shows a cross-section in a Y-direction. FIG. 4 is a top view of the film-forming portion in the film-forming apparatus of this embodiment.
• In FIGS. 2A and 2B, a[0041]substrate holder202 is provided in a film-formingchamber201, and asubstrate203 is supported by thesubstrate holder202. In this case, a substrate surface facing downward in the figure is a surface on which a thin film is to be formed.
• Further, a vapor-[0042]deposition mask204 is provided in the vicinity of thesubstrate203. The vapor-deposition mask204 is supported by amask holder205, and the distance between the vapor-deposition mask204 and thesubstrate203 can be adjusted by rendering themask holder205 variable.
• Further, an[0043]adhesion preventing shield206 is provided so as to surround thesubstrate203, the vapor-deposition mask204, and themask holder205. A region denoted with207 in theadhesion preventing shield206 can cover a vapor-deposition source until a sublimation speed of a vapor-deposition material is stabilized. More specifically, the region can have the same role as that of the vapor-deposition shield110 shown in FIG. 1A.
• Further, in a lower portion of the film-forming[0044]chamber201, a vapor-deposition source holder209 equipped with vapor-deposition sources208 and alamp light source210 are attached to arail211. More specifically, the film-forming portion of this embodiment is provided with a mechanism for moving the vapor-deposition sources208 and thelamp light source210 along therail211. Further, infrared light, UV-light, or visible light are radiated by thelamp light source210.
• Herein, FIG. 3A shows structures of the vapor-[0045]deposition source208 and the vapor-deposition source holder209. As shown in FIG. 3A, the film-forming portion of this embodiment has a structure in which a plurality of vapor-deposition sources208 are arranged on the vapor-deposition source holder209 in an elongated rectangular shape. The number of vapor-deposition sources208 is not limited, and the arrangement interval thereof may also be appropriately determined
• FIG. 3B shows a structure of the vapor-[0046]deposition source208. The vapor-deposition source208 shown in FIG. 3B is used for forming an organic EL material into a film, and provided withnozzles214 for a host material for vapor-depositing a host material andnozzles215 for a guest material for vapor-depositing a guest material.
• At this time, the movement speed of the vapor-[0047]deposition sources208 and the sublimation speed of the vapor-deposition material are controlled by acontrol unit212. Similarly, the movement speed and illumination of thelamp light source210 are also controlled by thecontrol unit212. Further, the movement speed and sublimation speed of the vapor-deposition sources208 should be controlled by giving feedback on the results of monitoring a film thickness of the vapor-deposition material formed on thesubstrate203 with a film thickness meter. Further, this control can also be conducted individually for each vapor-deposition source. In this case, by partitioning thesubstrate203 in a matrix, setting a plurality of crystal oscillators so that they correspond to the respective partitions, and controlling the vapor-deposition speed of each vapor-deposition source, the uniformity of a film thickness can be enhanced.
• Further, as the[0048]lamp light source210, a lamp emitting infrared light (infrared light lamp), a lamp emitting UV-light (UV-light lamp), or a lamp emitting visible light (typically, a halogen lamp) is used. Further, the shape of thelamp light source210 is a rectangle or an oblong, so that it can irradiate a large area at once by irradiation during movement. More specifically, an irradiated surface (surface of a equipment to which light is radiated) of infrared light, UV-light, or visible light emitted from thelamp light source210 becomes a rectangle or an oblong.
• According to the present invention, after the[0049]substrate203 is taken out of the film-formingchamber201, the vapor-deposition material adhering to the vapor-deposition mask204, themask holder205, and theadhesion preventing shield206 is irradiated with infrared light, UV-light, or visible light emitted from thelamp light source210. Then, the vapor-deposition material is re-sublimated by light irradiation, and exhausted through anexhaust port213 by using a vacuum pump (not shown). Although depending upon the temperature for sublimating the vapor-deposition material, it is preferable to use infrared light that is likely to generate heat by absorption.
• It is also effective to form a thin film (light-absorbing film) that is likely to absorb infrared light, UV-light, or visible light on an inner side of the[0050]adhesion preventing shield206 and the surface of themask holder205. More specifically, infrared light, UV-light, or visible light is once allowed to be absorbed by the light-absorbing film, and the adhering vapor-deposition material may be re-sublimated by heat conduction from the light-absorbing film.
• The film-forming apparatus of this embodiment enables cleaning in the film-forming chamber by very simple means; more specifically, the apparatus includes means (specifically, a lamp light source) for irradiating infrared light, UV-light, or visible light to equipments provided in the film-forming chamber, and uses the means to re-sublimate a vapor-deposition material adhering to the equipments or a vapor-deposition mask so as to exhaust (remove) the material. Further, the film-forming apparatus of this embodiment has conspicuous features that cleaning in the film-forming chamber can be conducted without exposing the inside of the chamber to the atmosphere. Therefore, the conventional problem of adsorbed water or oxygen can be avoided.[0051]
• Further, as shown in this embodiment, by prescribing a lamp light source in a rectangular or oblong shape, a large area can be irradiated by scanning (movement) at once. Thus, a time required for a cleaning process can be shortened, which enhances throughput.[0052]
Embodiment 2
• In this embodiment, a method of cleaning a film-forming apparatus will be described, which is characterized in that equipments provided in a film-forming chamber are heated with radiation heat to sublimate a vapor-deposition material adhering to the equipments, and the sublimated vapor-deposition material is exhausted. Radiation heat may be generated by flowing a current through a metal line (typically, a nichrome line) with high electrical resistance. Further, this embodiment is one example of the present invention, and can cite the above description.[0053]
• FIGS.[0054]5A-5B show cross-sectional structures of a film-forming portion in a film-forming apparatus of this embodiment. FIGS. 5A and 5B show cross-sectional structures taken in directions vertical to each other. FIG. 5A shows a cross-section in an X-direction, and FIG. 5B shows a cross-section in a Y-direction. Further, FIG. 6 is a top view of the film-forming portion in the film-forming apparatus of this embodiment.
• In FIGS. 5A and 5B, a[0055]substrate holder502 is provided in a film-formingchamber501, and asubstrate503 is supported by thesubstrate holder502. In this case, a substrate surface facing downward in the figure is a surface on which a thin film is to be formed.
• Further, a vapor-[0056]deposition mask504 is provided in the vicinity of thesubstrate503. The vapor-deposition mask504 is supported by amask holder505, and the distance between the vapor-deposition mask504 and thesubstrate503 can be adjusted by rendering themask holder505 variable.
• Further, an[0057]adhesion preventing shield506 is provided so as to surround thesubstrate503, the vapor-deposition mask504, and themask holder505. A region denoted with507 in theadhesion preventing shield506 can cover vapor-deposition sources until a sublimation speed of a vapor-deposition material is stabilized. More specifically, the region can have the same role as that of the vapor-deposition shield110 shown in FIG. 1A.
• Further, on the periphery of the[0058]adhesion preventing shield506, heating wires (in this embodiment, nichrome lines)508 are provided in contact therewith. In this embodiment, by flowing a current through theheating wires508, the entireadhesion preventing shield506 can be heated.
• Further, a[0059]reflective plate509 is provided so as to cover theadhesion preventing shield506. Thereflective plate509 may be one or provided in a plurality of number. Thereflective plate509 is provided for the purpose of reflecting radiation heat from theadhesion preventing shield506 and theheating wires508 to efficiently heat theadhesion preventing shield508. Further, it is also effective to minimize heating of the inner wall of the film-formingchamber501. As a material for thereflective plate509, it is preferable to use metal with a high reflectivity. Further, in the case of flowing gas in the film-formingchamber501, it is required to use metal with corrosion resistance to the gas.
• Further, in a lower portion of the film-forming[0060]chamber501, a vapor-deposition source holder511 equipped with vapor-deposition sources510 is attached to arail512. More specifically, the film-forming portion of this embodiment is provided with a mechanism for moving the vapor-deposition sources510 along therail512. The structures of the vapor-deposition sources510 and the vapor-deposition source holder511 are as shown in FIGS.3A-3B.
• Further, the movement speed of the vapor-[0061]deposition sources510 and the sublimation speed of the vapor-deposition material are controlled by acontrol unit513. In this embodiment, the movement speed and sublimation speed of the vapor-deposition sources510 are controlled by giving feedback on the results of monitoring a film thickness of the vapor-deposition material formed on thesubstrate503 with a film thickness meter. Further, this control is conducted individually for each vapor-deposition source. In this case, by partitioning thesubstrate503 in a matrix, setting a plurality of crystal oscillators so that they correspond to the respective partitions, and controlling the vapor-deposition speed of each vapor-deposition source, the uniformity of a film thickness can be enhanced.
• According to the present invention, by flowing a current through the[0062]heating wires507 after thesubstrate503 is taken out of the film-formingchamber501, theadhesion preventing shield506 is heated, and the adhesion material adhering to theadhesion preventing shield506 is re-sublimated. Then, the vapor-deposition material is exhausted through anexhaust port514 by using a vacuum pump (not shown). Although depending upon the temperature for sublimating the vapor-deposition material, an organic material would be sufficiently sublimated even at a temperature of 500° C. or lower.
• The film-forming apparatus of this embodiment enables cleaning in the film-forming chamber by very simple means; more specifically, a equipment provided in the film-forming chamber is equipped with conductors (heating wires, specifically, nichrome lines) for heating the equipment with radiation heat, and a current is flowed through the conductors to re-sublimate the vapor-deposition material adhering to the equipment and exhaust (remove) it. Further, since cleaning in the film-forming chamber is possible without exposure to the atmosphere, the conventional problem of adsorbed water or oxygen can be avoided.[0063]
Embodiment 3
• In this embodiment, a film-forming apparatus will be described in which an exhaust treatment chamber is connected to a film-forming chamber. In the film-forming apparatus of this embodiment shown in FIG. 7, a film-forming[0064]chamber702 has the same structure as that shown in FIG. 2A, and anexhaust treatment chamber701 is connected in series to the film-formingchamber702. Thus, regarding the film-formingchamber702, Embodiment 1 will be referred to, and theexhaust treatment chamber701 will be mainly described.
• In FIG. 7, the[0065]exhaust treatment chamber701 is connected to the film-formingchamber702 through agate703. Thegate703 plays a role in preventing exhaust gas from being mixed in the film-formingchamber702 from theexhaust treatment chamber701.Heating wires704 are provided at a pipe in the vicinity of thegate703, and thepipe705 can be heated. Theheating wires704 are provided so as to prevent the vapor-deposition material exhausted from the film-formingchamber701 from adhering to thepipe705.
• In the[0066]exhaust treatment chamber701, anupper electrode706 and alower electrode707 are provided in theexhaust treatment chamber701, and a high-frequency power supply708 is connected to theupper electrode706. Further, thelower electrode707 is grounded. Further, gas for forming plasma can be supplied to the inside of theexhaust treatment chamber701, and by applying a voltage between theupper electrode706 and thelower electrode707,plasma709 can be formed.
• The vapor-deposition material exhausted from the film-forming[0067]chamber702 is exposed to theplasma709 in theexhaust treatment chamber701, and changed to inactive gas by decomposition or bonding to be exhausted from anexhaust port710. More specifically, the re-sublimated vapor-deposition material is exposed to plasma during the exhaust and changed to inactive gas; therefore, there will not be a problem that the vapor-deposition material adheres onto the pipe after theexhaust port710.
• If the vapor-deposition material is an organic material (including an organic EL material), it is preferable to use oxygen as gas for forming plasma and to process the vapor-deposition material with oxygen plasma. However, care should be taken so that oxygen remaining in the[0068]exhaust treatment chamber701 will not flow in a reverse direction to the film-formingchamber702.
• Note that the structure of this embodiment may be combined with either of Embodiment 1 or 2.[0069]
Embodiment 4
• In this embodiment, the case will be described in which gas containing a halogen-group element is flowed in a film-forming chamber when a vapor-deposition material adhering to equipments is re-sublimated in a film-forming apparatus with the structure of either of Embodiments 1 to 3.[0070]
• Typical examples of the halogen-group element include fluorine, chlorine, bromine, and iodine. Typical examples of the gas containing these halogen-group elements include fluorine (F[0071]₂) gas, chlorine (Cl₂) gas, and carbon tetrafluoride (CF₄) gas.
• In this embodiment, a re-sublimated vapor-deposition material is reacted with the above-mentioned gas containing a halogen-group element to be changed to inactive gas, whereby the vapor-deposition material is prevented from adhering to the equipments, pipes, and inner walls of the film-forming chamber again.[0072]
• The structure of this embodiment can be combined with either of Embodiments 1 to 3.[0073]
Embodiment 5
• In this embodiment, a film-forming apparatus will be described in which a plurality of film-forming chambers with the structure of either of Embodiments 1 to 4 are provided by a multi-chamber system (also called a cluster tool system). FIG. 8 shows a schematic view of a film-forming apparatus of this embodiment. In this embodiment, a film-forming apparatus for forming an EL element is shown.[0074]
• In FIG. 8,[0075]reference numeral801 denotes a transport chamber, and thetransport chamber801 is provided with a transport mechanism (A)802 for transporting asubstrate803. Thetransport chamber801 is exposed to the reduced-pressure atmosphere, and is connected to each treatment chamber via a gate. The substrate is transferred to each treatment chamber by the transport mechanism (A)802 when the gate is opened. Further, in order to reduce the pressure in thetransport chamber801, an exhaust pump such as an oil rotary pump, a mechanical boster pump, a turbo molecular pump, or a cryopump can be used. However, a cryopump that is effective for removing moisture is preferable.
• Hereinafter, each treatment chamber will be described. Since the[0076]transport chamber801 is exposed to the reduced-pressure atmosphere, an exhaust pump (not shown) is provided in each treatment chamber directly connected to thetransport chamber801. As the exhaust pump, the above-mentioned oil rotary pump, mechanical boster pump, turbo molecular pump, or cryopump is used.
• First,[0077]reference numeral804 denotes a load chamber for setting a substrate, and is referred to as a load lock chamber. Theload chamber804 is connected to thetransport chamber801 via agate800a, in which a carrier (not shown) on which thesubstrate803 is set is disposed. Theload chamber804 may be separated into a portion for input of a substrate and a portion for output of a substrate. Further, theload chamber804 is provided with the above-mentioned exhaust pump and a purge line for introducing high-purity nitrogen gas or noble gas.
• Next,[0078]reference numeral805 denotes a pretreatment chamber for treating the surface of a positive electrode or a negative electrode (in this embodiment, a positive electrode) of an EL element, and thepretreatment chamber805 is connected to thetransport chamber801 via agate800b. The pretreatment chamber may be changed variously depending upon the manufacturing process of EL elements. In this embodiment, the pretreatment chamber is designed in such a manner that the positive electrode can be heated at 100° C. to 120° C. while the surface of the positive electrode made of a conductive oxide film is irradiated with UV-light. Such pretreatment is effective for treating the surface of a positive electrode of an EL element.
• Next,[0079]reference numeral806 denotes a film-forming chamber for forming an organic material and an organic EL material into films by vapor deposition, and referred to as a film-forming chamber (A). The film-forming chamber (A)806 is connected to thetransport chamber801 via agate800c. In this embodiment, as the vapor-deposition chamber (A)806, the film-forming portion shown in Embodiment 1 or 2 is provided. In this embodiment, in the film-forming chamber (A)806, an organic material to be a hole injection layer and an organic EL material to be a light-emitting layer that develops red color are formed into films. Thus, a vapor-deposition source and a vapor-deposition mask are provided in two kinds so that switching can be made.
• Next,[0080]reference numeral807 denotes a film-forming chamber for forming an organic EL material into a film by vapor deposition, and is referred to as a film-forming chamber (B). The film-forming chamber (B)807 is connected to thetransport chamber801 via agate800d. In this embodiment, as the film-forming chamber (B)807, the film-forming chamber shown in Embodiment 1 or 2 is provided. In this embodiment, in the film-forming chamber (B)807, an organic EL material to be a light-emitting layer that develops green color is formed into a film.
• Next,[0081]reference numeral808 denotes a film-forming camber for forming an organic EL material into a film by vapor deposition, and is referred to as a film-forming chamber (C). The film-forming chamber (C)808 is connected to thetransport chamber801 via agate800e. In this embodiment, the film-forming chamber shown in Embodiment 1 or 2 is provided as the film-forming chamber (C)808. In this embodiment, in the film-forming chamber (C)808, an organic EL material to be a light-emitting layer that develops blue color is formed into a film.
• Next,[0082]reference numeral809 denotes a film-forming chamber for forming a conductive film to be a positive electrode or a negative electrode (in this embodiment, a metal film to be a negative electrode) of a EL element by vapor deposition, and is referred to as a film-forming chamber (D). The film-forming chamber (D)809 is connected to thetransport chamber801 via agate800f. In this embodiment, as the film-forming chamber (D)809, the film-forming chamber shown in Embodiment 1 or 2 is provided. In this embodiment, in the film-forming chamber (D)809, an Al—Li alloy film (alloy film of aluminum and lithium) is formed as a conductive film to be a negative electrode of an EL element. An element belonging to Group I or Group II of the periodic table and aluminum can be vapor-deposited together.
• Next,[0083]reference numeral810 denotes a sealing chamber that is connected to theload chamber804 via agate 800 g. The sealingchamber810 is provided with a UV-lamp811. Further, the sealingchamber810 is connected to atransfer chamber812. Thetransfer chamber812 is provided with a transfer mechanism (B)813 that transports a substrate which is completed for sealing of an EL element in the sealingchamber810 to thetransfer chamber812.
• At this time, in the sealing[0084]chamber810, the step of sealing (enclosing) a formed EL element into a sealed space is conducted. More specifically, a sealant is attached to an EL element with UV-curable resin so as to cover it, and the UV-curable resin is cured with UV-light emitted from a UV-light lamp811 to seal the EL element.
• As described above, by using the film-forming apparatus shown in FIG. 8, an EL element is not exposed to the outside air until it is sealed in a sealed space completely. Therefore, a light-emitting device with high reliability can be manufactured.[0085]
• Further, by using the film-forming chamber of the present invention as the film-forming chamber (A)[0086]806, the film-forming chamber (B)807, the film-forming chamber (C)808, and the film-forming chamber (D)809, each film-forming chamber can be cleaned without being exposed to the atmosphere. Thus, a light-emitting device with higher reliability can be manufactured.
Embodiment 6
• In this embodiment, a film-forming apparatus will be described in which a plurality of film-forming chambers with the structure of either of Embodiments 1 to 4 are provided in an in-line system. FIG. 9 shows a schematic view of a film-forming apparatus of this embodiment. In this embodiment, a film-forming apparatus for forming an EL element will be shown.[0087]
• In FIG. 9,[0088]reference numeral901 denotes a load chamber, from which asubstrate90 is transported. Theload chamber901 is provided with anexhaust system900a. Theexhaust system900aincludes afirst valve91, a turbomolecular pump92, asecond valve93, and a rotary pump (oil rotary pump)94.
• The[0089]first valve91 is a main valve, which may also function as a conductance valve or use a butterfly valve. Thesecond valve93 is a fore valve. First, thesecond valve93 is opened, and the pressure in theload chamber901 is roughly reduced by therotary pump94. Then, thefirst valve91 is opened, and the pressure of theload chamber901 is reduced to high vacuum by the turbomolecular pump92. A mechanical boster pump or a cryopump can be used in place of the turbo molecular pump. The cryopump is particularly effective for removing moisture.
• Next,[0090]reference numeral902 denotes a pretreatment chamber for treating the surface of a positive electrode or a negative electrode (in this embodiment, a positive electrode) of an EL element, and thepretreatment chamber902 is provided with anexhaust system900b. Further, thepretreatment chamber902 is sealed by a gate (not shown) so as to be isolated from theload chamber901. Thepretreatment chamber902 can be changed variously depending upon the manufacturing process of an EL element.
• As the pretreatment, ozone plasma treatment, oxygen plasma treatment, argon plasma treatment, neon plasma treatment, helium plasma treatment, or hydrogen plasma treatment can be conducted. Further, by providing a heater, heating can be conducted simultaneously with plasma treatment. Further, it is also effective to enable UV-light irradiation to be conducted by providing a UV-light lamp.[0091]
• In this embodiment, the surface of a positive electrode made of a conductive oxide film is subjected to ozone plasma treatment while the substrate is being heated at 100° C., whereby pretreatment for enhancing a work function of the surface of the positive electrode is conducted while moisture is being removed.[0092]
• Next,[0093]reference numeral903 denotes a film-forming chamber for forming an organic material into a film by vapor deposition, and referred to as a film-forming chamber (A). The film-forming chamber (A)903 is provided with anexhaust system900c. The film-forming chamber (A)903 is sealed by a gate (not shown) so as to be isolated from thepretreatment chamber902. In this embodiment, the film-forming chamber shown in Embodiment 1 or 2 is used as the film-forming chamber (A)903, and a hole injection layer is formed in the film-forming chamber (A)903.
• Next,[0094]reference numeral904 refers to a film-forming chamber for forming an organic material into a film by vapor deposition, and is referred to as a film-forming chamber (B). The film-forming chamber (B)904 is provided with anexhaust system900d. Further, the film-forming chamber (B)904 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (A)903. In this embodiment, as the film-forming chamber (B)904, the film-forming chamber shown in Embodiment 1 or 2 is used, and a hole transport layer is formed in the film-forming chamber (B)904.
• Next,[0095]reference numeral905 refers to a film-forming chamber for forming an organic EL material into a film by vapor deposition, and is referred to as a film-forming chamber (C). The film-forming chamber (C)905 is provided with anexhaust system900e. Further, the film-forming chamber (C)905 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (B)904. In this embodiment, as the film-forming chamber (C)905, the film-forming chamber shown in Embodiment 1 or 2 is used, and a light-emitting layer that develops red color is formed in the film-forming chamber (C)905.
• Next,[0096]reference numeral906 refers to a film-forming chamber for forming an organic EL material into a film by vapor deposition, and is referred to as a film-forming chamber (D). The film-forming chamber (D)906 is provided with anexhaust system900fFurther, the film-forming chamber (D)906 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (C)905. In this embodiment, as the film-forming chamber (D)906, the film-forming chamber shown in Embodiment 1 or 2 is used, and a light-emitting layer that develops green color is formed in the film-forming chamber (D)906.
• Next,[0097]reference numeral907 refers to a film-forming chamber for forming an organic EL material into a film by vapor deposition, and is referred to as a film-forming chamber (E). The film-forming chamber (E)907 is provided with anexhaust system900g. Further, the film-forming chamber (E)907 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (D)906. In this embodiment, as the film-forming chamber (E)907, the film-forming chamber shown in Embodiment 1 or 2 is used, and a light-emitting layer that develops blue color is formed in the film-forming chamber (E)907.
• Next,[0098]reference numeral908 refers to a film-forming chamber for forming an organic material into a film by vapor deposition, and is referred to as a film-forming chamber (F). The film-forming chamber (F)908 is provided with anexhaust system900h. Further, the film-forming chamber (F)908 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (E)907. In this embodiment, as the film-forming chamber (F)908, the film-forming chamber shown in Embodiment 1 or 2 is used, and an electron transport layer is formed in the film-forming chamber (F)908.
• Next,[0099]reference numeral909 refers to a film-forming chamber for forming an organic material into a film by vapor deposition, and is referred to as a film-forming chamber (G). The film-forming chamber (G)909 is provided with an exhaust system900i. Further, the film-forming chamber (G)909 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (F)908. In this embodiment, as the film-forming chamber (G)909, the film-forming chamber shown in Embodiment 1 or 2 is used, and an electron injection layer is formed in the film-forming chamber (G)909.
• Next,[0100]reference numeral910 refers to a film-forming chamber for forming a conductive film to be a positive electrode or a negative electrode (in this embodiment, a metal film to be a negative electrode) of an EL element by vapor deposition, and is referred to as a film-forming chamber (H). The film-forming chamber (H)910 is provided with anexhaust system900j. Further, the film-forming chamber (H)910 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (G)909. In this embodiment, as the film-forming chamber (H)910, the film-forming chamber shown in Embodiment 1 or 2 is used.
• Further, in this embodiment, in the film-forming chamber (H)[0101]910, an Al—Li alloy film (alloy film of aluminum and lithium) or an Al-Cs alloy film (alloy film of aluminum and cesium) is formed as a conductive film to be a negative electrode of an EL element. An element belonging to Group I or Group II of the periodic table and aluminum can be vapor-deposited together.
• Next,[0102]reference numeral911 denotes a sealing chamber, which is provided with anexhaust system900k. Further, the sealingchamber911 is sealed by a gate (not shown) so as to be isolated from the film-forming chamber (H)910. In the sealingchamber911, in order to protect an EL element from oxygen and moisture, a carbon film, more specifically, a DLC (diamond-like carbon) film is formed as a passivation film.
• In order to form the DLC film, sputtering, plasma CVD, or ion plating may be used. In the case of using ion plating, the film-forming apparatus with the structure of Embodiment 1 may be used. In the case of ion plating, unlike ordinary vapor deposition, an electrode for applying an electric field thereto is required. However, a vapor-deposition material adhering to the electrode may be re-sublimated by light irradiation from a lamp light source and exhausted.[0103]
• The DLC film can be formed in a temperature range from room temperature to 100° C., so that the DLC film is preferable as a passivation film for protecting an EL element with low heat resistance. Further, the DLC film has high heat conductivity and a good heat radiation effect; therefore, the effect of suppressing thermal degradation of an EL element can also be expected. It is also effective that the DLC film formed in this embodiment is used by being stacked with a silicon nitride film or a silicon carbide film.[0104]
• Finally,[0105]reference numeral912 denotes an unload chamber, which is provided with anexhaust system9001. A substrate with an EL element formed thereon is taken out from the unloadchamber912.
• It is effective to operate each treatment chamber, exhaust system, and transport system in the film-forming apparatus shown in this embodiment by computer control. In the case of this embodiment, since an EL element is completed by continuously conducting a series of treatments, the input of a substrate to the output thereof can be managed by computer control.[0106]
• As described above, by using the film-forming apparatus shown in FIG. 9, an EL element is not required to be exposed to the outer atmosphere until it is completely sealed in a sealed space. Therefore, an EL display apparatus with high reliability can be manufactured. Further, due to the in-line system, an EL display apparatus with high throughput can be manufactured.[0107]
• Further, by using the film-forming chamber of the present invention as the film-forming chamber (A)[0108]903, the film-forming chamber (B)904, the film-forming chamber (C)905, the film-forming chamber (D)906, the film-forming chamber (E)907, the film-forming chamber (F)908, the film-forming chamber (G)909, and the film-forming chamber (H)910, each film-forming chamber can be cleaned without being exposed to the atmosphere. Thus, a light-emitting device with high reliability can be manufactured.
Embodiment 7
• In this embodiment, a method of manufacturing an electro-optical device (in this embodiment, a light-emitting device including an EL element) including the cleaning method with the structure of either of Embodiments 1 to 4 will be described.[0109]
• Each flowchart in FIGS.[0110]10A-10B shows a flow of the steps of manufacturing a light-emitting device in this embodiment. First, FIG. 10A shows an example in which a film-forming apparatus is cleaned by the method of either of Embodiments 1 to 4 every time an organic material (also containing an organic EL material) for forming an EL element is formed into a film. In this case, the film-forming apparatus ofEmbodiment 5 or 6 may be used.
• In this case, after the step of manufacturing a TFT on an insulator (TFT manufacturing step), the step of forming an organic material for forming an EL element into a film (film-forming step of an organic material) is conducted, and the step of sealing an EL element (sealing step) is conducted, whereby a light-emitting device is completed. In these series of manufacturing steps, immediately after the film-forming step of an organic material is completed, the step of cleaning the film-forming apparatus is conducted, and thereafter, the subsequent film-forming step of an organic material is conducted.[0111]
• A method of manufacturing an active matrix type light-emitting device includes the step of manufacturing a TFT. However, a method of manufacturing a passive matrix type light-emitting device or a light source including an EL element does not include the step of manufacturing a TFT. In this respect, the step of manufacturing a TFT is represented by using parentheses.[0112]
• Next, FIG. 10B shows an example in which a film-forming apparatus is cleaned by the method of either of Embodiments 1 to 4 after the film-forming step of an organic material (also including an organic EL material) for forming an EL element is conducted a plurality of times. More specifically, when the film thickness of a vapor-deposition material adhering to equipments provided in a film-forming chamber reaches a film thickness to some degree, the cleaning step is periodically conducted.[0113]
• In this case, in the steps of manufacturing a light-emitting device continuously conducted, after the film-forming step of an organic material is conducted with respect to a plurality of substrates, the step of cleaning the film-forming apparatus is conducted, and thereafter, the subsequent film-forming step of an organic material is conducted.[0114]
Embodiment 8
• In this embodiment, exemplary steps of manufacturing a passive matrix type light-emitting device including an EL element will be described.[0115]
• First, as shown in FIG. 1A, a[0116]positive electrode12 made of a conductive oxide film is formed on asubstrate11 with an insulating film formed on a surface thereof, and partition walls13 are formed on thepositive electrode12. The partition wall13 is composed of a firstpartition wall portion13amade of a silicon oxide film, a secondpartition wall portion13bmade of a resin film, and a thirdpartition wall portion13cmade of a silicon nitride film.
• At this time, the first[0117]partition wall portion13amay be patterned by photolithography. Further, the shapes of the secondpartition wall portion13band the thirdpartition wall portion13care obtained by etching a resin film to be the secondpartition wall portion13band a resin film to be the thirdpartition wall portion13cto the same shape, and thereafter, etching the resin film to be the secondpartition wall portion13bin an isotropic manner, using the thirdpartition wall portion13cas a mask.
• Next, the step of forming an organic material for forming an EL element into a film by using the film-forming apparatus shown in[0118]Embodiment 5 is conducted. First, surface treatment of thepositive electrode12 is conducted in thepretreatment chamber805, and ahole injection layer14 and a light-emitting layer (R)15 are formed in the film-forming chamber (A)806. The light-emitting layer (R) is a light-emitting layer that emits red light.
• Next, a light-emitting layer (G)[0119]16 is formed in the film-forming chamber (B)807, and a light-emitting layer (B)17 is formed in the film-forming chamber (C)808. The light-emitting layer (G) is a light-emitting layer that emits green light, and the light-emitting layer (B) is a light-emitting layer that emits blue light.
• Next, an Al—Li alloy film obtained by vapor-depositing aluminum (Al) and lithium (Li) together is formed as a[0120]negative electrode18. Then, a sealing step is conducted in the sealingchamber810, whereby a passive matrix type light-emitting device is completed.
• At this time, after the[0121]hole injection layer14, the light-emitting layer (R)15, the light-emitting layer (G)16, the light-emitting layer (B)17, or thenegative electrode18 is formed, cleaning of each film-forming chamber may be conducted by using the structure shown in either of Embodiments 1 to 4. It is appreciated that cleaning may be conducted for each film formation as shown in FIGS.10A-10B, or cleaning may be conducted after the film-forming step is conducted a plurality of times.
• Further, in this embodiment, the film-forming apparatus shown in[0122]Embodiment 5 is used. However, the film-forming apparatus shown in Embodiment 6 may be used.
Embodiment 9
• In this embodiment, exemplary steps of manufacturing an active matrix type light-emitting device including an EL element will be described.[0123]
• First, thin film transistors (hereinafter, referred to as “TFTs”)[0124]22 are formed on asubstrate21 with an insulating film formed on its surface by a known manufacturing step, as shown in FIG. 12A. Then, as shown in FIG. 12B, apositive electrode23 made of a conductive oxide film and an insulatingfilm24 made of a silicon oxide film are formed.
• Then, the step of forming an organic material for forming an EL element is conducted by using the film-forming apparatus shown in[0125]Embodiment 5. First, surface treatment of thepositive electrode23 is conducted in thepretreatment chamber805, and ahole injection layer25 and a light-emitting layer (R)26 are formed in the film-forming chamber (A)806. The light-emitting layer (R) is a light-emitting layer that emits red light.
• Then, a light-emitting layer (G)[0126]27 is formed in the film-forming chamber (B)807, and a light-emitting layer (B)28 is formed in the film-forming chamber (C)808. The light-emitting layer (G) is a light-emitting layer that emits green light, and the light-emitting layer (B) is a light-emitting layer that emits blue light.
• Next, an Al—Li alloy film obtained by co-vapor-depositing aluminum (Al) and lithium (Li) together is formed as a[0127]negative electrode29. Then, a sealing step is conducted in the sealingchamber810, whereby an active matrix type light-emitting device is completed.
• At this time, after the[0128]hole injection layer25, the light-emitting layer (R)26, the light-emitting layer (G)27, the light-emitting layer (B)28, or thenegative electrode29 is formed, cleaning of each film-forming chamber may be conducted by using the structure shown in either of Embodiments 1 to 4. It is appreciated that cleaning may be conducted for each film formation as shown in FIGS.10A-10B, or cleaning may be conducted after the film-forming step is conducted a plurality of times.
• Further, in this embodiment, the film-forming apparatus shown in[0129]Embodiment 5 is used. However, the film-forming apparatus shown in Embodiment 6 may be used.
Embodiment 10
• In Embodiment 9, an example has been shown in which a top gate type TFT (specifically, a planar type TFT) is manufactured as the[0130]TFT22. However, in this embodiment, as shown in FIGS.13A-13C, aTFT30 is used in place of theTFT22. TheTFT30 used in this embodiment is a bottom gate type TFT (specifically, an inverted stagger type TFT) which may be formed by a known manufacturing step.
• The other structure is the same as that in Embodiment 9. Therefore, the detailed description in this embodiment and the description of reference numerals will be omitted.[0131]
• By carrying out the present invention, a film-forming apparatus (vapor-deposition apparatus) can be cleaned without exposing equipments provided in the apparatus or the inner wall of a film-forming chamber to the atmosphere. Therefore, a time required for cleaning the equipments or the like can be shortened, which leads to reduction of the steps of manufacturing an electro-optical device.[0132]
• In particular, in the case where a light-emitting device including an EL element is manufactured by conducting the cleaning method of the present invention, degradation of an organic EL material for forming an EL element due to adsorbed oxygen or water can be reduced; therefore, a light-emitting device with good reliability can be manufactured.[0133]

Claims (26)

What is claimed is:

1. A film-forming apparatus characterized by having means for irradiating a component provided in a film-forming chamber with at least one selected from the group consisting of infrared light, UV-light, and visible light.

2. A film-forming apparatus characterized by having a lamp light source for irradiating a component provided in a film-forming chamber with at least one selected from the group consisting of infrared light, UV-light, and visible light.

3. A film-forming apparatus according toclaim 2, characterized in that the lamp light source is in a rectangular or oblong shape.

4. A film-forming apparatus characterized by having means for heating a component provided in a film-forming chamber with radiation heat.

5. A film-forming apparatus, characterized in that a component provided in a film-forming chamber is equipped with a conductor for heating the component with radiation heat.

6. A film-forming apparatus according toclaim 1, characterized in that the component is an adhesion preventing shield.

7. A film-forming apparatus according toclaim 1, characterized in that an exhaust treatment chamber is connected to the film-forming chamber.

8. A film-forming apparatus according toclaim 7, characterized in that plasma is generated in the exhaust treatment chamber.

9. A method of cleaning a film-forming apparatus, comprising the steps of: irradiating a component provided in a film-forming chamber with at least one selected from the group consisting of infrared light, UV-light, and visible light, thereby sublimating a vapor-deposition material adhering to the component; and exhausting the sublimated evaporation material.

10. A method of cleaning according toclaim 9, characterized in that at least one selected from the group consisting of the infrared light, UV-light, and visible light is radiated by using a lamp light source provided in the film-forming chamber.

11. A method of cleaning according toclaim 9, characterized in that an irradiation surface of at least one selected from the group consisting of the infrared light, UV-light, and visible light is in a rectangular or oblong shape.

12. A method of cleaning according toclaim 9, characterized in that, in the sublimation step, gas containing a halogen-group element is flowed in the film-forming chamber.

13. A method of cleaning according toclaim 9, characterized in that the sublimated vapor-deposition material is exposed to plasma during exhaust.

14. A method of cleaning according toclaim 13, characterized in that the plasma is oxygen plasma.

15. A method of cleaning according toclaim 9, characterized in that the vapor-deposition material is an organic EL material.

16. A method of manufacturing an electro-optical device including the method of cleaning ofclaim 9.

17. A method of manufacturing an electro-optical device including the method of cleaning ofclaim 9.

18. A film-forming apparatus according toclaim 2, characterized in that the component is an adhesion preventing shield.

19. A film-forming apparatus according toclaim 2, characterized in that an exhaust treatment chamber is connected to the film-forming chamber.

20. A film-forming, apparatus according toclaim 19, characterized in that plasma is generated in the exhaust treatment chamber.

21. A film-forming apparatus according toclaim 4, characterized in that the component is an adhesion preventing shield.

22. A film-forming apparatus according toclaim 4, characterized in that an exhaust treatment chamber is connected to the film-forming chamber.

23. A film-forming apparatus according toclaim 22, characterized in that plasma is generated in the exhaust treatment chamber.

24. A film-forming apparatus according toclaim 5, characterized in that the component is an adhesion preventing shield.

25. A film-forming apparatus according toclaim 5, characterized in that an exhaust treatment chamber is connected to the film-forming chamber.

26. A film-forming apparatus according toclaim 25, characterized in that plasma is generated in the exhaust treatment chamber.

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