JP2001059161A - Device for producing organic thin film and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for producing an organic thin film that the distance can be set shortly between an evaporating source and a substrate corresponding to a substrate of a relatively large area, a material corresponding to a film forming content for one time can be fed to, easily and selectively execute painting operation, moreover it can cope with mixtures and doped organic materials and furthermore it can cope with vapor deposition at a relatively low temperature, and to provide a method for producing it. SOLUTION: This device for producing an organic thin film has a raw material feeding source 2 feeding a raw material soln. 1 in which an organic material is dissolved in a solvent, a feeding atm. controlling means 3 controlling a raw material soln. from the raw material feeding source to a fixed atm. and feeding it, a vaporizing means vaporizing the fed raw material soln. and a substrate 5 in which the vaporized raw material is deposited, and a film is formed, and the vaporizing means has an evaporating dish 4 stored with the fed raw material soln. by a prescribed amt. and a heating means of heating the raw material soln. stored into the evaporating dish to a temp. higher than the vaporizing temp. of the organic material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for producing an organic thin film such as a constituent thin film of an organic EL device.
More specifically, the present invention relates to an organic thin film manufacturing apparatus and an organic thin film manufacturing method using a vapor deposition method in which an organic material is evaporated by heating and deposited on a film formation region on a substrate to form a thin film.

[0002]

2. Description of the Related Art As one of basic techniques for forming a thin film,
A vacuum deposition method is known. In this vacuum deposition method, an evaporation source and a film-forming substrate are appropriately combined in a vacuum chamber to form a thin film. Various means for producing an evaporation source have been considered, for example, Applied.Physics.Letter. Vol. 68, N
o.16,15 April 1996 A so-called resistance heating evaporation method is known in which an electric current is applied to a metal container (metal boat) having a relatively high electric resistance and the raw material is evaporated by the heat generated, as described in P2276 to 2278. ing. Also known is an electron beam / laser beam evaporation method in which a raw material is directly irradiated with an electron beam or a laser beam, and the raw material is evaporated with the energy. Above all, a film forming method using resistance heating (resistance heating evaporation method) has a simple configuration of a manufacturing apparatus,
It is widely used because it can realize high quality thin film formation at low cost.

In the resistance heating evaporation method, a metal material such as tungsten, tantalum or molybdenum having a high melting point is processed into a thin plate, and a raw material container (metal boat) is manufactured from a metal plate having a high electric resistance. A direct current is passed, and the heat is used to evaporate the raw material to supply an evaporative gas.
Part of the evolved gas deposits on the substrate, forming a thin film.

Incidentally, the evaporation sources used in these vapor deposition methods can be approximated as point evaporation sources. JP-A-10-3350
No. 62 discloses a technique for increasing the distance between the evaporation source and the substrate, rotating the substrate, and disposing the evaporation source from the substrate rotation center in order to form a thin film having a uniform thickness on a large-area substrate. Are being considered. However,
In this method, since the distance between the evaporation source and the substrate is large, it is difficult to efficiently use expensive organic materials. In addition, a pseudo surface evaporation source using a plurality of evaporation sources requires a film thickness controller to keep the evaporation rate of the material from each evaporation source constant, which is difficult to realize.

In the case where several types of organic thin films are formed on a single substrate in different regions or only in specific regions, a method using a shadow mask or the like is generally used. However, since the distance between the evaporation source and the substrate is large, when the evaporation source is offset, the thickness of the shadow mask forms a shadow, and it is difficult to apply a fine pattern to the shadow mask. . Further, if mask deposition is performed without performing the offset arrangement or the rotation of the substrate, it is necessary to further increase the distance between the evaporation source and the substrate, and the use efficiency of the organic material is further reduced.

In recent years, organic EL devices have been actively studied. This is because a hole transporting material such as triphenyldiamine (TPD) is deposited on the hole injecting electrode to form a thin film, a fluorescent substance such as an aluminum quinolinol complex (Alq3) is laminated as a light emitting layer, and a work function such as Mg is further laminated. It is an element having a basic structure in which a small metal electrode (electron injection electrode) is formed, and is attracting attention because a very high luminance of several hundreds to several 10,000 cd / m ² can be obtained at a voltage of about 10 V.

Conventionally, when manufacturing a product to which an organic EL element is applied, a functional thin film made of an organic material is formed by using the above-described vapor deposition method. In such a mass production process, it is an important issue how to increase the productivity and how to increase the use efficiency of the material. However, the manufacturing apparatus using the conventional vapor deposition apparatus is inefficient in the use of materials, wastes expensive organic materials, and requires a complicated painting operation when trying to obtain an RGB full-color display. It has been difficult to increase the accuracy of painting.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to cope with a substrate having a relatively large area, to set a short distance between the evaporation source and the substrate, and to cope with one deposition. Organic thin film manufacturing equipment that can supply materials to be applied, can easily perform the coating operation of the organic thin film, can handle mixtures and doped organic materials, and can also support relatively low temperature deposition. It is to realize a manufacturing method.

[0009]

The above object is achieved by the following constitutions (1) to (9). (1) A raw material supply source for supplying a raw material solution in which an organic material is dissolved in a solvent, supply amount adjusting means for adjusting the raw material solution from the raw material supply source to a constant amount, and supplying the raw material solution A vaporizing means for vaporizing the solution; and a substrate on which the vaporized raw material is deposited and formed into a film. The vaporizing means includes an evaporating dish for storing a predetermined amount of the supplied raw material solution, and an evaporating dish stored in the evaporating dish. An organic thin film manufacturing apparatus having heating means for heating the raw material solution to a temperature higher than the vaporization temperature of the organic material. (2) The apparatus for producing an organic thin film according to the above (1), wherein a distance from a top end face of the raw material solution stored in the vaporizing means to a film forming surface is 10 to 160 mm. (3) The apparatus for producing an organic thin film according to (1) or (2), wherein the evaporating dish has a plurality of recesses for storing a raw material liquid. (4) The apparatus for producing an organic thin film according to (3), wherein the concave portions of the evaporating dish are connected to each other by a raw material liquid path. (5) The heating temperature of the heating means is 200 to 50.
The apparatus for producing an organic thin film according to any one of (1) to (4), wherein the temperature is 0 ° C. (6) The apparatus for producing an organic thin film according to any one of (1) to (5), wherein the heating means is a halogen lamp. (7) The above-mentioned (1) to (1), wherein the heating means is a resistance heater closely formed at least on the bottom of the evaporating dish.
(5) The apparatus for producing an organic thin film according to any of (5). (8) The supply amount adjusting means controls the flow rate of the raw material solution by a mass flow control method, and controls the supply time of the raw material solution to adjust the supply amount.
(7) The apparatus for producing an organic thin film according to any of (7). (9) The apparatus for producing an organic thin film according to any one of (1) to (7), wherein the supply amount adjusting unit adjusts the supply amount by a dispenser method. (10) The organic thin film according to any one of (1) to (9) above, further comprising a pressure adjusting means for setting a pressure in the apparatus at the time of supplying the raw material solution higher than a pressure at the time of evaporation of the solvent and the organic material. manufacturing device. (11) The apparatus for producing an organic thin film according to the above (10), wherein the pressure adjusting means adjusts the pressure by supplying an inert gas into the apparatus. (12) The apparatus for producing an organic thin film according to any one of (1) to (11), wherein the organic material is a mixture of two or more organic substances. (13) The apparatus for producing an organic thin film according to any one of the above (1) to (5), which forms a thin film constituting an organic EL element. (14) The apparatus for manufacturing an organic thin film according to any one of (1) to (13) above, which has an alignment adjustment mechanism for the substrate. (15) The alignment adjustment mechanism includes: a substrate; a shadow mask disposed in proximity to the substrate; The organic thin film manufacturing apparatus according to the above (14), wherein the relative position is adjusted. (16) The apparatus for producing an organic thin film according to any one of (1) to (15), wherein the substrate has a maximum length of 200 to 1000 mm. (17) A method for producing an organic thin film, wherein a film is formed using the production apparatus according to any one of (1) to (16).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An apparatus for producing an organic thin film according to the present invention comprises:
A raw material supply source for supplying a raw material solution in which an organic material is dissolved in a solvent, a supply amount adjusting means for adjusting the raw material solution from the raw material supply source to a fixed amount and supplying the raw material solution, and vaporizing the supplied raw material solution Vaporizing means, and a substrate on which the vaporized raw material is deposited to form a film. The vaporizing means comprises an evaporating dish for storing a supplied raw material solution in a predetermined amount, and a raw material solution stored in the evaporating dish. Is heated to a temperature higher than the vaporization temperature of the organic material.

As described above, the organic material to be formed into a film is dissolved in a solvent, this raw material solution is adjusted to a predetermined amount and supplied. By evaporating and forming a film, the distance between the evaporation source and the substrate can be reduced while maintaining a good film thickness distribution, and the use efficiency of the material is improved. Further, the film composition and the film thickness can be accurately adjusted, and continuous film formation can be performed.

The raw material supply source holds a raw material solution dissolved in an organic solvent and supplies it as needed. Such a raw material supply source may be any container, tank, or the like that can store a predetermined amount of the raw material solution. The shape and size are not particularly limited, and an appropriate capacity,
What is necessary is just to be a shape. In addition, the material is not particularly limited, but it is necessary that the material does not dissolve or corrode in the organic solvent and does not react with or bind to the organic material as the raw material.

The raw material solution held in the raw material supply source is:
It is obtained by dissolving an organic material as a raw material in an organic solvent. By dissolving the organic material in the solvent, the amount of the raw material supplied to the evaporating means can be easily and appropriately controlled, and the supplied raw material solution is entirely evaporated without directly controlling the thickness of the deposited film. A desired film thickness can be easily obtained simply by performing the above operation.

At this time, if two or more kinds of organic materials are adjusted in advance in a desired concentration ratio and dissolved in a solvent, the desired solution can be obtained by simply evaporating the raw material solution without directly controlling the deposition rate. Can be obtained.

The organic material used as a raw material is not particularly limited as long as it can form a film by a vapor deposition method, and various organic materials can be used. For example, chain polymers such as polyacetylene and polyyne, or π-electron conjugated organic semiconductor substances such as molecular crystals of polyacene (such as anthracene) and metal chelate compounds (such as copper phthalocyanine), anthracene, diethylamines, p-phenylenediamine, A compound serving as a donor such as tetramethyl-p-phenylenediamine (TMPD) or tetrathiofulvalene (TTF); and tetracyanoquinodimethane (TC
NQ), tetracyanoethylene (TCNE), a charge transfer complex composed of a compound serving as an acceptor such as p-chloroanil, a dye material, a fluorescent material, a liquid crystal material, and the like.

The vaporization temperature of these organic materials is usually about 150 to 500 ° C., especially about 20
About 0 to 400 ° C. is preferable. When two or more materials are used, it is necessary to heat the material to the highest vaporization temperature or higher. Further, it is necessary to heat at the decomposition temperature of the material used. The concentration of the organic material in the solvent is 0.1 to 5
0 wt%, particularly preferably about 5 to 20 wt%.

Among these organic materials, especially organic EL
Good results can be obtained by using an organic material for the element constituent film. The constituent films of the organic EL element are a hole injection / transport layer, a light emitting layer, an electron injection / transport layer, and the like, and these constituent thin films, particularly the light emitting layer, require precise control of the film thickness and composition. Therefore, by using the apparatus of the present invention, it is possible to accurately control the film thickness and control the composition, thereby improving and stabilizing the quality of the organic EL device, and providing a new device having higher performance. It becomes possible.

Examples of the organic substance used in the light emitting layer of the organic EL element include a fluorescent substance which is a compound having a light emitting function. As such a fluorescent substance, for example, at least one kind selected from compounds such as quinacridone, rubrene, styryl dyes and the like as disclosed in JP-A-63-264692 is exemplified. A quinoline derivative such as a metal complex dye having 8-quinolinol or a derivative thereof as a ligand, such as tris (8-quinolinolato) aluminum; tetraphenylbutadiene, anthracene, perylene, coronene;
12-phthaloperinone derivatives and the like. Further, Japanese Patent Application Laid-Open No. 8-12600 (Japanese Patent Application No. 6-1105)
69), and a tetraarylethene derivative disclosed in JP-A-8-12969 (Japanese Patent Application No. 6-114456).

In some cases, a host material capable of emitting light by itself and a dopant are used in combination. Thereby, the emission wavelength characteristic of the host substance can be changed, and light emission shifted to a longer wavelength becomes possible.
The luminous efficiency and stability of the device are improved. In such a case, the content of the compound in the light emitting layer is preferably 0.01
-20% by volume, more preferably 0.1-15% by volume.

The host substance is preferably a quinolinolato complex, and more preferably an aluminum complex having 8-quinolinol or a derivative thereof as a ligand. Such an aluminum complex is disclosed in JP-A-63-26469.
No. 2, JP-A-3-255190, JP-A-5-7073
3, JP-A-5-258859, JP-A-6-2158
No. 74 and the like.

Specifically, first, tris (8-quinolinolato) aluminum, bis (8-quinolinolato) magnesium, bis (benzo {f} -8-quinolinolato) zinc, bis (2-methyl-8-quinolinolato) aluminum Oxide, tris (8-quinolinolato) indium,
Tris (5-methyl-8-quinolinolato) aluminum, 8-quinolinolatolithium, tris (5-chloro-
8-quinolinolato) gallium, bis (5-chloro-8-
Quinolinolato) calcium, 5,7-dichloro-8-quinolinolatoaluminum, tris (5,7-dibromo-
8-hydroxyquinolinolato) aluminum and poly [zinc (II) -bis (8-hydroxy-5-quinolinyl) methane].

Other host materials are disclosed in
Phenylanthracene derivative described in JP-A-12600 (Japanese Patent Application No. 6-110569) and JP-A-8-1296
No. 9 (Japanese Patent Application No. 6-114456) is also preferable.

The light emitting layer is preferably a mixed layer of at least one kind of hole injecting and transporting compound and at least one kind of electron injecting and transporting compound, if necessary.
Further, it is preferable that a dopant is contained in the mixed layer. The content of the compound in such a mixed layer is preferably 0.01 to 20% by volume, more preferably 0.1 to 15% by volume.

The hole injecting and transporting compound and the electron injecting and transporting compound used in the mixed layer may be selected from the hole injecting and transporting compound and the electron injecting and transporting compound described below, respectively. Among them, as the compound capable of injecting and transporting holes, it is preferable to use an amine derivative having strong fluorescence, for example, a triphenyldiamine derivative which is a hole transporting material, further a styrylamine derivative, or an amine derivative having an aromatic condensed ring. .

As the compound capable of injecting and transporting electrons, it is preferable to use a quinoline derivative, furthermore a metal complex having 8-quinolinol or its derivative as a ligand, particularly tris (8-quinolinolato) aluminum (Alq3). It is also preferable to use the above-mentioned phenylanthracene derivatives and tetraarylethene derivatives.

The mixing ratio in this case depends on the respective carrier mobility and carrier concentration. In general, the weight ratio of the compound of the hole injecting and transporting compound / the compound having the electron injecting and transporting function is 1/99 to less. 99/1, more preferably 10/90 to 90/10, particularly preferably 20/80
It is preferable to set it to about 80/20.

The thickness of the mixed layer is preferably not less than the thickness corresponding to one molecular layer and less than the thickness of the organic compound layer. Specifically, the thickness is preferably 1 to 85 nm, more preferably 5 to 60 nm, particularly preferably 5 to 50 nm.

The hole injecting and transporting layer is described in, for example,
JP-A-3-295695, JP-A-2-191694, JP-A-3-792, JP-A-5-234681
JP, JP-A-5-239455, JP-A-5-5-2
JP-A-99174, JP-A-7-126225, JP-A-7-126226, JP-A-8-100172
Various organic compounds described in JP-A No. 06509555 A1 and the like can be used. For example, a tetraarylbendicine compound (triaryldiamine or triphenyldiamine: TPD), an aromatic tertiary amine,
Examples include hydrazone derivatives, carbazole derivatives, triazole derivatives, imidazole derivatives, oxadiazole derivatives having an amino group, and polythiophene. These compounds may be used alone or in combination of two or more. When two or more kinds are used in combination, they may be stacked as separate layers or mixed.

The electron injecting / transporting layer includes a quinoline derivative such as an organometallic complex having 8-quinolinol such as tris (8-quinolinolato) aluminum (Alq3) or a derivative thereof as a ligand, an oxadiazole derivative, a perylene derivative, or the like. A pyridine derivative, a pyrimidine derivative, a quinoxaline derivative, a diphenylquinone derivative, a nitro-substituted fluorene derivative, or the like can be used.

The solvent for dissolving the organic material is preferably an organic solvent, and an optimum solvent may be used depending on the type of the organic material to be dissolved. It is necessary that the material does not dissolve or corrode the constituent material of the raw material supply source, the constituent material of the flow path, and the like. Its boiling point is 50-150 ° C,
In particular, about 60 to 100 ° C. is preferable. Specifically, tetrahydrofuran (THF) and the like are preferable.

The raw material supply means has a transport means for transporting the raw material solution, in addition to the container for holding the raw material solution. The transporting means can be appropriately selected from known means used for moving the liquid and used. Specifically, a method of applying a mechanical pressure of a liquid pump or the like to convey the material, applying a pressure to the raw material solution by air or a gas such as an inert gas, or conveying the raw material solution together therewith is used. Among these, those utilizing gas pressure are suitable for accurate flow rate adjustment.
Air, Ar, Ne, X
e, an inert gas such as Kr, N _{2 and the} like.
Among them, N _{2 and the} like are preferable.

The pump used if necessary is not particularly limited, and any pump capable of sending a fluid at a predetermined pressure may be used. However, a pump which does not dissolve in an organic solvent or is not deteriorated by this is used. preferable. Specifically, a centrifugal pump, a bellows pump, a roller pump, or the like can be used.

The supply amount adjusting means adjusts the supply amount of the raw material solution to be supplied so that the optimum supply amount is obtained. The supply amount adjusting means itself may have a function of sending and transporting the raw material solution, may be a means for adjusting the flow rate of the raw material solution supplied from the raw material supply means in advance, or may be any one. However, it is preferable that the supply amount can be accurately adjusted.

Since the thickness of the deposited film is controlled by controlling the supply amount of the liquid, it is possible to control the film thickness accurately with a relatively simple structure, and to reduce waste of expensive raw materials such as organic materials. can do.

More specifically, the control may be performed by using a variable flow control valve and a flow meter, and by a control method such as a mass flow control system. As the flow meter, a mass flow meter is preferable, but a differential pressure flow meter, an area flow meter, a volume flow meter, an electromagnetic flow meter, a turbine flow meter, a vortex flow meter, or the like can be used if necessary.

Further, the supply amount may be adjusted by a dispenser system in which an open / close valve, gas pressure control means, and time control means such as a timer are combined. In this case, a conductance adjusting means such as a needle may be provided in the flow path. The conductance control means may be controlled by changing the inner diameter of the needle valve provided in the transport path, or may be controlled by adjusting the opening of the needle valve.

The flow rate of the raw material solution adjusted by the supply amount adjusting means is not particularly limited, but is usually preferably 0.1 to 100 ml / min, particularly preferably about 1.0 to 50 ml / min. The accuracy of the controllable flow rate is usually
Those which can be adjusted within a range of ± 1% or less, ± 0.5% or less are particularly preferable.

The raw material vaporizing means heats and vaporizes the supplied raw material solution and supplies it to the film forming surface. That is, usually, the raw material vaporizing means has an evaporating dish for storing the supplied raw material solution in a predetermined amount, and a heating means for heating the raw material solution stored in the evaporating dish to a temperature higher than the vaporization temperature of the organic material. .

The evaporating dish uniformly holds and stores the supplied raw material solution. The size of the raw material dish is not particularly limited as long as it can cover the film formation surface, but it is usually preferable that the size is larger than the substrate.

In particular, when a uniform film thickness is required up to the edge of the substrate, it is effective to make the size of the evaporating dish larger than the outer shape of the substrate. In this case, the horizontal distance from the end of the substrate to the end of the evaporating dish varies in optimum value depending on the distance between the evaporating dish and the substrate, but is usually preferably 20 to 200 mm, particularly preferably 40 to 160 mm.

The volume of the raw material liquid stored in the evaporating dish is preferably 0.1 to 100 cm ³ , more preferably 1 to 100 cm ³ .
About 50 cm ³ . The shape of the evaporating dish may be cylindrical or rectangular box-like, but is usually square box-like along the substrate shape.

The material constituting the evaporating dish is not particularly limited as long as it can withstand a predetermined temperature and does not react with an organic solvent or an organic material. In particular,
What is used as a material for the crucible is preferable,
For example, Pyrolytic Boron Nitride (PB
N), ceramics such as alumina and silicon carbide (SiC), quartz and the like, and high melting point metals such as tungsten, tantalum and molybdenum. Further, since the vaporization temperature of the organic solvent and the organic material is relatively low, metal materials such as stainless steel and aluminum can be used. In particular, PBN, SiC, metal materials, and the like are preferable from the viewpoint of thermal responsiveness, and metal materials are preferable from the viewpoint of cost.

Further, when the raw material solution is not uniform in the evaporating dish, the film thickness distribution to be formed tends to vary. For this reason, the evaporating dish must be kept horizontal, and its levelness is usually 0.5 mm or less, especially 0.1 mm
The following is preferred. The levelness can usually be evaluated by the bottom surface on the liquid reservoir side of the evaporating dish, or the plane connecting the bottom surfaces when a plurality of concave portions are formed in the evaporating dish.

If necessary, a levelness adjusting mechanism may be provided. The levelness adjustment mechanism may be a levelness detection means such as a level, a micrometer head, a manual adjustment mechanism having a levelness adjustment means to which a set bolt or the like is applied, or a control means such as a processor, An automatic mechanism for automatically performing these adjustment operations may be used.

In the evaporating dish, it is preferable that the position from the top end surface of the stored raw material solution or the distance from the evaporation reference plane to the film formation surface of the substrate is 10 to 160 mm, particularly 20 to 120 mm. If the distance is shorter than this range, the film thickness distribution will not be uniform, and if the distance is longer, the use efficiency of the material will deteriorate.

When the area of the evaporating dish is large, a plurality of recesses may be formed at the bottom. In that case, the recesses to be formed may be formed so as to be arranged at regular intervals. The supplied raw material solution is held and stored in each concave portion.However, the raw material solution is supplied so that the liquid level of the raw material solution exceeds the upper end of the concave portion and the raw material solutions on each concave portion are connected and integrated. The structure of the evaporating dish may be so determined.

In order to make the raw material solution held and stored in each concave portion uniform, a raw material liquid path connecting the concave portions may be provided. The raw material liquid path can be constituted by, for example, a groove or a pipe. In this case, it is preferable that the depth of the groove or the opening of the tube is smaller than the depth of the concave portion. The width of the groove or the diameter or width of the tube is preferably smaller than the width of the recess.

Although the size of the concave portion depends on the size of the entire evaporating dish, it is usually preferably 0.5 to 50 mm, particularly preferably 5 to 25 mm in diameter, and the depth is 0.1 to 10 mm.
mm, especially about 1 to 5 mm. As the interval between the recesses,
The distance from the end of the recess to the end of the other recess is preferably 5 to 160 mm, more preferably 10 to 120 mm. In addition, as for the size of the groove or pipe,
Width: 0.1-5mm, especially 1-3mm, Depth: 0.1-5,
In particular, it is 1-3 mm, diameter: 0.1-3 mm, especially about 0.5-2 mm.

As a heating means for heating and vaporizing the raw material solution, various known heating means can be used. For example, any device having a predetermined heat capacity, reactivity, or the like may be used. For example, a heating unit for heating with a heater such as a tantalum wire heater or a sheath heater, a halogen lamp,
In addition, heating means such as an incandescent bulb may be used. The heating temperature by the heating means is preferably about 200 to 500 ° C., and the accuracy of temperature control varies depending on the material to be evaporated.

The thermal response speed of the evaporating dish is preferably high. For this reason, if the evaporating dish is heated through the quartz glass using a halogen lamp installed in the atmosphere, a relatively fast thermal response speed can be obtained. Further, the evaporating dish may be formed of a material having a relatively high thermal response speed such as the above-described PBN, and a thin film heater such as PG (Pyrolite Tech Graphite) may be directly formed in close contact.

To form a film in a specific region, a shadow mask may be used. The shadow mask is usually placed close to the substrate. Further, in order to ensure adhesion to the substrate, a shadow mask may be formed of a magnetic material, and the shadow mask may be brought into close contact with the substrate by a magnetic field generating means arranged on the back side of the substrate. In the case where the relative position accuracy between the shadow mask and the substrate is required, such as when the organic materials corresponding to the respective colors of RGB are separately applied, an alignment mechanism for adjusting the relative position between the substrate and the shadow mask may be provided. Good.

Specifically, the alignment may be adjusted by placing the substrate on an XY table and operating the XY table. These controls can be easily performed by a control device equipped with a processor such as a microcomputer. As the accuracy of the alignment adjustment mechanism,
It is preferred that it be ± 10 μm or less. The XY table usually includes a movable support (linear bearing or the like) having a degree of freedom in the XY axis direction, and a pulse motor, a servo motor, or the like for driving the table in the XY directions. ing.

In the case of performing different coating, a plurality of raw material supply sources, a supply amount adjusting means, and a raw material vaporizing means may be prepared, and different organic materials may be formed respectively. In this case, one or more film forming chambers may be prepared for each organic material.

The apparatus of the present invention may have a pressure adjusting means for keeping the pressure in the film forming chamber at an optimum level. The pressure adjusting means is not particularly limited as long as it can optimally maintain the pressure in the film formation chamber. However, since the inside of the film formation chamber is usually maintained at a predetermined degree of vacuum, an evacuation device or vacuum It is preferable to include a pump or the like and gas supply means for supplying a predetermined atmospheric gas so that the atmosphere and the pressure in the film formation chamber are constant.

In this case, as for the degree of vacuum in the film forming chamber, it is preferable that the pressure in the apparatus when the raw material solution is supplied is set higher than the pressure when the solvent and the organic material are evaporated.
Specifically, the pressure is preferably from 100 Pa to atmospheric pressure, particularly about 100 Pa to atmospheric pressure. The atmospheric gas supplied into the film formation chamber may be air from which moisture has been sufficiently removed, but is preferably N 2.
₂ or an inert gas such as Ar, He, Kr, and Xe, with N ₂ being particularly preferred. The supply capacity of the atmosphere gas depends on the size of the film forming chamber, but may be supplied at a flow rate of about 1 to 10 SLM. Further, a pressure automatic control means for automatically detecting the pressure in the film formation chamber due to the supplied gas and the flow rate of the gas supplied to the film formation chamber and controlling the same may be provided. These can be configured by known instruments and devices for controlling the gas flow rate and pressure.

After supplying the raw material solution, heating or depressurization may be performed to evaporate the solvent. Further, both heating and decompression may be performed. The heating and reduced pressure conditions are preferably such that the solvent evaporates and the organic material does not evaporate. Specifically, the heating temperature is preferably from 40 to 120C, particularly preferably from about 50 to 100C. Pressure in the vacuum is, 10 ^-6 ~10 ³ Pa, especially 10 ^-5 to 10 ² Pa in the range of about preferably.

The substrate is not particularly limited as long as an organic thin film can be laminated thereon. In particular, considering the application to an organic EL device or the like, when taking out emitted light, glass or quartz, Use a transparent or translucent material such as resin. Further, the emission color may be controlled by using a color filter film, a color conversion film containing a fluorescent substance, or a dielectric reflection film on the substrate. If the emitted light is not taken out, the substrate may be transparent or opaque,
If opaque, ceramics or the like may be used.

The size of the substrate is not particularly limited, but preferably has a maximum length, particularly a diagonal length of 200 to 100.
0 mm, particularly preferably in the range of 400 to 700 mm. Although there is no problem even if the maximum length is 200 mm or less, a uniform film thickness distribution can be obtained particularly with a substrate having a length of 200 mm or more.
On the other hand, if the size of the substrate exceeds 1000 mm, the film forming apparatus becomes large, and control becomes difficult.

Next, the present invention will be described more specifically with reference to the drawings.

FIG. 1 is a schematic diagram showing the basic structure of a film forming apparatus according to the present invention. In the figure, the organic thin film manufacturing apparatus of the present invention comprises a raw material storage tank 2 as a raw material supply means, a mass flow controller 3 as a supply amount adjusting means, an evaporating dish 4 as a raw material vaporization means, and an organic thin film. And a substrate 5 to be filmed. Further, the evaporating dish 4 and the substrate 5 are arranged in the film forming chamber 8 so that the film can be formed under a predetermined atmosphere (degree of vacuum) while being shielded from the external atmosphere. An exhaust device 9 is connected to the film forming chamber 8 via a duct 14 so that the inside of the film forming chamber 8 can be maintained at a predetermined degree of vacuum (a reduced pressure atmosphere) during film formation.

The film forming chamber 8 is connected via a gate valve 15 to a loader, an unloader, and a vacuum working chamber 16 for transferring a substrate to and from a working chamber in another process. The vacuum working chamber 16 can transfer a work without exposing the work from the film forming chamber 8 to the atmosphere.

When the film forming apparatus of the present invention is used as a part of an organic EL element manufacturing apparatus as shown in FIG. 2, for example,
Particularly favorable results can be obtained. In FIG.
The apparatus for manufacturing an organic EL element includes a loader chamber 21 connected to a vacuum transfer chamber 31 having a robot arm 62,
A first vapor deposition chamber 32, a second vapor deposition chamber 33, a first sputtering chamber 34, a second sputtering chamber 35, and an unloader chamber 4;
And 1.

The loader chamber 21, the first vapor deposition chamber 32, the second vapor deposition chamber 33, and the first sputtering chamber 34
, The second sputtering chamber 35, the unloader chamber 41, and the vacuum transfer chamber 31 are respectively connected to the gate valves 21b and 32.
a, 33a, 34a, 35a, and 41b, and connected to respective working chambers (a loader chamber, a first evaporation chamber, a second evaporation chamber, a first sputtering chamber, a second sputtering chamber, and an unloader chamber). ) Can be cut off from the atmosphere in the vacuum transfer chamber.

The loader chamber 21 is a work chamber for carrying a substrate on which a positive electrode such as ITO is formed and patterned, and has a role of a buffer chamber between the vacuum work chamber 62 and the outside atmosphere. First vapor deposition chamber 32 and second vapor deposition chamber 3
Reference numeral 3 denotes a working chamber for forming a film of an organic layer or the like of an organic EL element, and it is preferable that at least one of these working chambers has the film forming apparatus of the present invention. Also, the first sputtering chamber 34
The second sputtering chamber 35 is a work chamber for forming a functional thin film such as a negative electrode, a protection electrode, and a wiring electrode of the organic EL element. Further, the unloader chamber 41 is a work chamber for unloading the organic EL structure having various functional thin films formed on the substrate and transferring it to the next step.

The vacuum transfer chamber 31 is maintained at a predetermined degree of vacuum and has a robot arm 61 having a plurality of arms a, b, and c. Each of the work chambers (loader chamber, first vapor deposition chamber, The substrate is carried in and out of the second evaporation chamber, the first sputtering chamber, the second sputtering chamber, and the unloader chamber), and the substrate is interposed between the respective working chambers while being shielded from the external atmosphere. It can be handed over. The base of the robot arm 61 rotates in the direction indicated by the arrow in the figure, and can move up and down, left and right, and back and forth with a degree of freedom corresponding to the number of indirects.

By using the manufacturing apparatus shown in the illustrated example, an organic EL device can be manufactured very efficiently. In addition, in the illustrated example, two vacuum deposition chambers and two sputtering chambers are arranged in each working chamber, but the number and types of the film forming chambers can be appropriately adjusted depending on the element configuration of the organic EL element to be manufactured. it can. The loader room 21 and the unloader room 4
1 may be connected to the work chambers of the pre-process and the post-process, respectively.

The film forming apparatus shown in FIG. 1 will be described in further detail. A carrier gas such as N ₂ is supplied to the raw material storage tank 2 via a gas flow path 11. The gas flow path 11 is not particularly limited as long as it can transport a required amount of gas, and may be a pipe, a hose, or a duct. As the material, a material conventionally used for transporting a liquid (organic solvent) can be used, and preferably, a metal material such as stainless steel, copper, and aluminum can be used.

The raw material solution 1 is stored in the raw material storage tank 2, and when the carrier gas is introduced from the gas flow path 11, the raw material solution 1 is conveyed to the mass flow controller 3 through the raw material flow path 12 by the pressure. . This mass flow controller includes a mass flow meter. This mass flow meter, for example,
It has a basic configuration as shown in FIG.

FIG. 5 is a schematic partial sectional view of the mass flow controller 3. In the figure, a main flow path 301 and a sub flow path 302 are provided inside the mass flow controller and connected to the raw material flow paths 12 and 13. Now, assuming that the raw material solution flows from the direction of the arrow, the main flow path 30
In addition to the raw material solution flow flowing in 1, a raw material solution flow flowing in the sub flow path 304 is generated. The sub flow path 304 includes two coils L
1, L2 are wound and resistors R1, R2, R3, R
4, the resistors R1 and R2 of the bridge circuit
Are connected to both ends. This bridge circuit is set by a variable resistor R3 so as to be balanced under predetermined conditions (initial state, steady state, etc.). Coil L
1 and L2 are heated by a current source (not shown) with a predetermined heating value.

Here, when the bridge circuit is in an equilibrium state,
When the raw material solution flows in the sub flow path 304, the coils L1, L
There is a difference in temperature between the two. This temperature difference is determined by the coil L
1 and L2, the balance of the bridge circuit is lost, and a potential difference occurs between the input terminals of the amplifier Amp. This potential difference is proportional to the flow rate of the raw material solution flowing through the sub flow path 304. Since the raw material solution flows at a predetermined flow ratio between the sub flow path 304 and the main flow path 301, the overall flow rate and its change are determined by the input of the amplifier Amp. It can be grasped from the potential difference applied between the terminals. Then, this flow rate information is amplified by the amplifier Amp and is given to the control device 305 of the movable valve 302. The control device 305 is an amplifier
The movable shaft 303 is controlled based on the flow rate information given from the Amp, and the opening degree of the movable valve 302 is adjusted so that the raw material solution flowing in the main flow path 301 is controlled to a predetermined flow rate. In this way, the mass flow controller 3 can perform accurate flow control. In the above example, the case where the bridge circuit is in an equilibrium state has been described as a reference. However, the present invention is not limited to this, and a state having a predetermined potential difference may be used as a reference.

The raw material solution adjusted to an accurate flow rate by the mass flow controller 3 is conveyed to the evaporating dish 4 through the raw material flow path 13 and is vaporized.

A more specific configuration example of the evaporating dish 4 is shown in FIGS.
Shown in FIG. 4 is a partial cross-sectional view taken along the line AA ′ of FIG. The illustrated evaporating dish 4 has a main body 4, a concave portion 4a formed in the main body 4, and a groove 4b connecting the concave portions 4a, respectively. The raw material solution supplied onto the evaporating dish 4 is uniformly supplied to each concave portion 4a by the groove 4b, and the concave portion 4a is deeper than the groove 4b as can be seen from FIG. The raw material solution stored in the concave portion 4a evaporates.

In FIG. 1, a substrate 5 is disposed on an evaporating dish 4. The distance between the substrate 5 and the evaporating dish 4 is determined from the uppermost end surface of the raw material solution supplied to the evaporating dish 4 or the evaporation reference surface.
It is preferably in the range of 10 to 160 mm. Here, the evaporation reference surface refers to a reference surface approximated as an evaporation surface of the supplied raw material solution.

The organic material as the vaporized raw material is formed on the substrate 5.

The heating means of the evaporating dish 4 is connected to the heating control device 7, and the heating is controlled by electric power (current) given from the heating control device 7. The heating control device 7 has temperature detecting means 6 disposed on the evaporating dish 4, and controls electric power (current) supplied to the heating means according to the temperature information of the evaporating dish 4 given from the temperature detecting means 6. I do.

The heating control device 7 can be constituted by a general-purpose microprocessor (MPU) as a control unit and a control algorithm on a storage medium (ROM, RAM, etc.) connected to the MPU. Also, CISC,
It can be used regardless of the mode of the processor such as RISC and DSP, and can also be constituted by an ASIC, a combination of logic circuits by a general IC or the like, or an analog arithmetic circuit using an operational amplifier or the like. And
A power (current) control unit including a semiconductor element such as a bipolar transistor, a MOS-FET, a triac, a UJT, or an SCR may be controlled by a control signal from the control unit.

The temperature control method is not particularly limited as long as it can appropriately control the temperature. For example, hardware (analog, digital circuit) using a PID (proportional integral derivative) control method is applied. Alternatively, a control algorithm developed from the above may be used.

The temperature detecting means 6 may be any one which can appropriately detect the temperature of the raw material vaporizing means, and examples thereof include thermocouples such as platinum-platinum rhodium and tungsten-tungsten rhenium.

The atmosphere at the time of film formation in the film formation chamber is usually in a vacuum state. The pressure during film formation is preferably 1 × 10 ⁻⁶ to 1
At x10 ^-3 Pa, the heating temperature is higher than the vaporization temperature of the organic material, and is usually preferably from 200 to 500 ° C, particularly preferably from about 250 to 450 ° C.

Of the above components, the raw material supply source is mainly composed of the raw material storage tank 2 and the carrier gas supplied from the transport path 11, and the supply amount adjusting means is mainly controlled by the mass flow controller 3. The raw material vaporizing means is mainly constituted by the evaporating dish 4. The heating means of the raw material vaporizing means is mainly constituted by an electric heating ball such as a heater or a halogen lamp arranged on the evaporating dish 4, a temperature detecting means 6 and a heating control device 7.

[0081]

EXAMPLE A film forming apparatus having the structure shown in FIGS. 1 to 3 was prepared, and an organic thin film for a light emitting layer of an organic EL device was formed.

The corresponding substrate was 200 mm square, and the size of the evaporating dish was 300 mm square. The distance between the evaporating dish and the substrate was set to 100 mm. The material of the evaporating dish was aluminum, and a recess having the cross-sectional shape of FIG. 4 was formed in the arrangement shown in FIG. Each recess was connected by a groove having a width of 2 mm and a depth of 2 mm. A halogen lamp was arranged in a quartz glass tube introduced into the vacuum chamber by an O-ring seal, and a heating mechanism for heating the evaporating dish from the atmosphere side through the quartz glass tube was provided. The effective emission wavelength of the halogen lamp was 350 mm.

A thermocouple is placed on the bottom of the evaporating dish to measure the temperature, and the PI of the halogen lamp output is measured using a temperature controller.
D control was performed. Three means for adjusting the supply amount of the raw material solution by the mass flow control system were provided.

As shown in FIG. 2, the two evaporation chambers 32 and 33 were connected to the two sputtering chambers 34 and 35, the loader chamber 21 and the unloader chamber 41 via the vacuum transfer chamber 31. A vacuum gate valve was provided between each chamber and the vacuum transfer chamber. Each chamber was provided with an independent evacuation system. The evaporation chambers 32 and 33 and the spack chambers 34 and 35 were provided with a shadow mask holding mechanism and a substrate alignment mechanism. The vacuum transfer chamber 31 is provided with a multi-joint type substrate transfer robot 61.

A 200 mm square non-alkali glass was used as a substrate, and an ITO electrode layer and the like were formed in a predetermined pattern and formed on the substrate. The pattern formed on the substrate is a pattern corresponding to a full-color matrix of 64 × 128 dots, the size of each pixel is 300 mm square, and the size of each sub-pixel is 90 × 300 mm.
Each color was arranged in a line.

After the substrate surface was subjected to the UV / O ₃ treatment, it was put into the loader room 21 of the film forming apparatus. At this time, the vacuum transfer chamber 3
1. The vapor deposition chambers 32 and 33 and the spack chambers 34 and 35 were each evacuated to 1 × 10 ⁻⁴ Pa or less. Loader room 21
Is evacuated to 10 Pa or less, and the vacuum transfer chamber 31 and the loader chamber 2
Open the gate valve 21a between the first and second vacuum transfer chambers 3
Conveyed to 1. Next, the vacuum transfer chamber 31 and the loader chamber 2
After closing the gate valve 21a between the vacuum transfer chambers 3
Open the gate pulp 32a between the first and the first deposition chamber 32,
The substrate was transported to the first vapor deposition chamber 32.

In the first vapor deposition chamber 32, a shadow mask made of a magnetic material and having an opening corresponding to the size of each pixel was provided. After the substrate and the shadow mask were aligned, the substrate and the shadow mask were brought into close contact with each other by an electromagnetic magnet as a magnetic field generating means.

Tetrahydrofuran (THF: boiling point = 80
4,4 ', 4 "-dissolved at a concentration of 1.0 g / ml
Tris (-N- (3-methylphenyl) -N-phenylamino) triphenylamine (hereinafter, m-MTDAT
A), N, dissolved in THF at a concentration of 1.0 mg / ml.
N'-diphenyl-N, N'-m-tolyl-4,4'-
Diamino-1,1′-biphenyl (hereinafter, TPD), T
Tris (8-quinolinolato) aluminum (Alq3: vaporization temperature = 30) dissolved in HF at a concentration of 0.5 mg / ml
(0 ° C.), and 500 ml of each was supplied to the supply sources of the mass flow systems 1, 2, and 3, respectively.

After introducing N ₂ into the first vapor deposition chamber 32 and increasing the pressure to 100,000 Pa, the mass flow system (1)
Then, 12 ml of the m-MTDATA solution was uniformly supplied to each recess of the evaporating dish. The vapor deposition chamber was evacuated again, and when the pressure became 1 × 10 ⁻⁴ Pa or less, the vapor deposition dish was heated to 300 ° C., and m-MT
DATA was deposited on the substrate.

Next, similarly, 4.8 ml of the TPD solution was supplied by the mass flow system (2), the evaporating dish was heated to 300 ° C. to vaporize the TPD, and then the substrate was transferred to the second vapor deposition chamber. In the second evaporation chamber, a shadow mask made of a magnetic material, in which an opening corresponding to one sub-pixel was formed for each pixel, was arranged.

As a raw material for the red light-emitting layer, Alq3 doped with 1% by weight of dicyanomethylpyran (hereinafter referred to as DCM: vaporization temperature = 290 ° C.) was dissolved in THF at a concentration of 0.5 mg / mI to obtain a mass flow system 1 500 ml was charged to the supply source.

Alq 3 doped with 1% by weight of coumarin 6 as a raw material for the green light emitting layer was dissolved in THF to a waste of 0.5 mg / ml, and 500 ml was supplied to the supply source of the mass flow system 2.

DPA was used as a raw material for the blue light emitting layer in THF.
Was dissolved at a concentration of 1.0 mg / ml, and 500 ml was supplied to the source of the mass flow system 3.

First, the substrate and the shadow mask were aligned and brought into close contact with the substrate such that the positions of the sub-pixels on the substrate corresponding to the red light-emitting layer faced the openings of the shadow mask. As in the case of the first evaporation chamber, 24 ml of an Alq3 + DCM solution was supplied from the mass flow system (1), and the evaporation dish was heated to 300 DEG C. for evaporation.

Next, the substrate and the shadow mask were aligned and brought into close contact with the substrate such that the position of the sub-pixel on the substrate corresponding to the green light emitting layer was opposed to the opening of the shadow mask.

Similarly, from the mass flow system (2), Alq3
+ Coumarin 6 solution was supplied in an amount of 24 ml, and the evaporating dish was heated to 300 ° C.
And evaporated.

Further, the substrate and the shadow mask were aligned so that the positions of the sub-pixels on the substrate corresponding to the blue light emitting layer and the openings of the shadow mask were opposed to each other, and were brought into close contact with the substrate.

Similarly, from the mass flow system (3), the DPA
After supplying 12 ml of the solution and heating the evaporating dish to 300 ° C. for vapor deposition, the substrate was transferred to the first vapor deposition chamber 32.

In the first vapor deposition chamber 32, the same alignment is performed, and 4.8 of the Alq3 solution is supplied from the mass flow system (3).
Then, the evaporating dish was heated to 300 ° C. and steamed.

Next, the substrate was transported to the first sputtering chamber, Al-Li (Li: 7 at%) was spacked to a thickness of 5 nm, and the substrate was transported to the second sputtering chamber to transfer Al of 200 nm. Sputtered to a thickness. At this time, a shadow mask having an opening corresponding to a portion where the upper metal electrode pattern was formed was arranged in the sputtering chamber, and alignment and close contact were performed as in the case of the evaporation chamber.

The obtained organic EL display was set to 10 mA / cm.
When time-division driving was performed at a current density of ² , it was confirmed that all the pixels of RGB emitted light normally and operated. Further, while the same film thickness distribution as that obtained by vapor deposition using a Knudsen cell while rotating the substrate at a substrate-evaporation source distance of about 400 mm was obtained, the amount of material used was reduced to about 1/5.

In the above embodiment, a halogen lamp was used as the heating means. However, similar results were obtained when heating by a heater closely attached to the evaporating dish was used.

[0103]

As described above, according to the present invention, it is possible to set the distance between the evaporation source and the substrate short, corresponding to a substrate having a relatively large area, and to cope with one deposition. Organic thin film manufacturing equipment that can supply materials to be applied, can easily perform the coating operation of the organic thin film, can handle mixtures and doped organic materials, and can also support relatively low temperature deposition. A manufacturing method can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a basic configuration example of a manufacturing apparatus of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a configuration example of an apparatus for manufacturing an organic EL element.

FIG. 3 is a cross-sectional view showing a specific configuration example of an evaporating dish.

FIG. 4 is a cross-sectional view taken along a line A-A ′ of FIG. 3;

FIG. 5 is a cross-sectional view illustrating a configuration example of a mass flow control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw material solution 2 Raw material storage tank 3 Mass flow controller 4 Evaporating dish 5 Substrate 6 Temperature detecting means 7 Heating control device

Continuation of the front page (72) Inventor Michio Arai 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDC Corporation F term (reference) 3K007 AB18 EB00 FA01 FA03 4K029 BA62 BD01 CA01 CA05 DA01 DB11 DB17

Claims (17)

[Claims] 1. A raw material supply source for supplying a raw material solution in which an organic material is dissolved in a solvent, supply amount adjusting means for adjusting the raw material solution from the raw material supply source to a constant amount and supplying the raw material solution. Vaporizing means for vaporizing the raw material solution, and a substrate on which the vaporized raw material is deposited and formed into a film. The vaporizing means includes an evaporating dish for storing a supplied raw material solution in a predetermined amount, and an evaporating dish for the evaporating dish. An apparatus for producing an organic thin film having a heating means for heating a stored raw material solution to a temperature higher than the vaporization temperature of the organic material. 2. The organic thin film manufacturing apparatus according to claim 1, wherein a distance from an uppermost end face of the raw material solution stored in the vaporizing means to a film forming surface is 10 to 160 mm. 3. The organic thin film manufacturing apparatus according to claim 1, wherein the evaporating dish has a plurality of recesses for storing a raw material liquid. 4. The organic thin film manufacturing apparatus according to claim 3, wherein the concave portions of the evaporating dish are connected to each other by a raw material liquid path. 5. The apparatus for producing an organic thin film according to claim 1, wherein a heating temperature of said heating means is 200 to 500 ° C. 6. The apparatus according to claim 1, wherein said heating means is a halogen lamp. 7. The heating device according to claim 1, wherein said heating means is a resistance heater closely attached to at least the bottom of the evaporating dish.
5. The apparatus for producing an organic thin film according to any one of the above items 5. 8. The organic thin film according to claim 1, wherein said supply amount adjusting means controls the flow rate of the raw material solution by a mass flow control method, and controls the supply time of the raw material solution to adjust the supply amount. Manufacturing equipment. 9. The apparatus for producing an organic thin film according to claim 1, wherein said supply amount adjusting means adjusts the supply amount by a dispenser method. 10. A pressure in the apparatus at the time of supplying the raw material solution,
The apparatus for producing an organic thin film according to any one of claims 1 to 9, further comprising pressure adjusting means for setting a pressure higher than a pressure at the time of evaporation of the solvent and the organic material. 11. The apparatus for producing an organic thin film according to claim 10, wherein said pressure adjusting means adjusts the pressure by supplying an inert gas into the apparatus. 12. The organic thin film manufacturing apparatus according to claim 1, wherein the organic material is a mixture of two or more organic substances. 13. The apparatus for producing an organic thin film according to claim 1, wherein the organic EL element constituting thin film is formed. 14. An apparatus for producing an organic thin film according to claim 1, further comprising an alignment adjustment mechanism for said substrate. 15. The organic thin film manufacturing apparatus according to claim 14, wherein the alignment adjusting mechanism adjusts a relative position between the substrate and a shadow mask disposed close to the substrate. 16. The substrate has a maximum length of 200 to 100.
The apparatus for producing an organic thin film according to claim 1, wherein the thickness is 0 mm. 17. A method for producing an organic thin film, wherein a film is formed using the production apparatus according to claim 1.