JP4156885B2 - Thin film forming equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thin film forming apparatus for forming, for example, an organic thin film used for a light emitting layer of an organic LED element by vapor deposition.
[0002]
[Prior art]
In recent years, organic LED elements have attracted attention as elements for full-color flat panel displays. An organic LED element is a self-luminous element that emits light by exciting a fluorescent organic compound electrically. It has high brightness, high viewing angle, surface light emission, thin and multicolor emission, and low voltage of several volts. This is an all-solid-state device that emits light when a direct current is applied, and has a feature that its characteristic change is small even at a low temperature.
[0003]
FIG. 7 is a schematic configuration diagram of a thin film forming apparatus for producing a conventional organic LED element.
As shown in FIG. 7, in this thin film forming apparatus 101, an evaporation source 103 is disposed below the vacuum chamber 102, and a substrate 104, which is a film formation target, is disposed above the evaporation source 103. Has been. An organic thin film having a predetermined pattern is formed by vapor-depositing an organic material evaporated from the evaporation source 103 on the substrate 104 through the mask 105.
[0004]
[Problems to be solved by the invention]
However, in such a conventional technique, since the substrate must be disposed in the upper part of the vacuum chamber (depot up), the mask has to be mechanically fixed, and the mask is distorted. .
In particular, this problem has become important as substrates have become larger in recent years.
[0005]
In addition, the conventional technology has a problem that it is difficult to form an organic thin film on a substrate that is easily bent.
[0006]
The present invention has been made in order to solve the above-described problems of the prior art, and is highly accurate for a large film-forming object or a flexible film-forming object without causing a problem of mask distortion. An object is to provide an evaporation source and a thin film forming apparatus capable of forming a pattern.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 comprises a vacuum chamber, an evaporation vessel provided in the vacuum chamber, having an elongated cylindrical shape and having an evaporation port in the lower portion, and provided in the evaporation vessel. In addition, the thin film forming apparatus includes an accommodating portion for accommodating the evaporation material, a heating unit for heating the evaporation container, and a cooling unit for cooling the evaporation container .
The invention according to claim 2 is the invention according to claim 1, wherein the evaporation port is configured to discharge the evaporation material vertically downward.
According to a third aspect of the present invention, in the second aspect of the present invention, an evaporation port is provided along the longitudinal direction of the evaporation container.
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the heating means is provided around the evaporation container.
The invention according to claim 5 is the invention according to any one of claims 1 to 4 , wherein the heating means is a resistance heating type heater.
The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the heating means is an induction heating type heater.
The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the evaporation container is provided with a monitor evaporation port.
The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the evaporation container is configured to move relative to the film formation target.
The invention according to claim 9 is the invention according to claim 8, wherein the moving direction of the evaporation container is the width direction of the evaporation container.
[0008]
Oite this onset bright, since the evaporation port for discharging the vapor of the evaporation material in a lower portion of the evaporation vessel provided in the vacuum chamber is provided, the film-forming target in a so-called Depodaun state down It becomes possible to perform vapor deposition.
[0009]
As a result, according to the present invention, it is possible to perform deposition by arranging a mask on the film formation target, so that the problem of mask distortion as in the prior art does not occur and Thus, a highly accurate pattern can be formed. Further, there is a problem that the mask extends due to heat radiation received from the vapor deposition source during vapor deposition. However, according to the present invention, a cooling mechanism can be provided under the film formation target, so that such a problem does not occur. .
[0010]
Moreover, even when the film formation target is easily bent, such as a film, a highly accurate pattern can be easily formed.
[0011]
Furthermore, in the present invention, since the heating means for heating the evaporation container is provided, the vapor of the evaporation material is not reflected and adhered to the inner surface of the evaporation container in the evaporation container. Steam can be efficiently discharged from the evaporation port.
[0012]
And in this invention, if it comprises so that evaporation material may be discharged | emitted vertically downward from an evaporation port, since a mask can be arrange | positioned on a pattern board | substrate, mask vapor deposition to the film-forming target object of a large area is carried out. There is a merit that it becomes possible.
[0013]
In addition, since the evaporation container is formed in an elongated cylindrical shape, by moving the evaporation container relatively in the width direction with respect to the film formation target, a large film formation target or a plurality of film formation targets can be obtained. On the other hand, when vapor deposition is performed, film formation with a uniform film thickness can be performed.
[0014]
In this case, in particular, by providing the evaporation port along the longitudinal direction of the evaporation container, the film thickness can be made more uniform.
[0015]
On the other hand, if the heating means is provided around the evaporation container, the evaporation material does not adhere to the heating means, and the structure of the evaporation container can be simplified.
[0016]
In this case, if a resistance heating type heater is used as the heating means, precise temperature control is possible, so that there is an advantage that a material (dopant) having a high vapor pressure can be evaporated.
[0017]
In addition, if an induction heating type heater is used as the heating means, the structure is simple, the heat capacity is small, and the structure can be cooled. is there.
[0018]
On the other hand, if the evaporation container for monitoring is provided in the evaporation container, it is always possible to accurately measure the evaporation rate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an evaporation source and a thin film forming apparatus using the same according to the present invention will be described below in detail with reference to the drawings.
[0020]
FIG. 1 is a front sectional view of a preferred embodiment of a thin film forming apparatus according to the present invention, and FIG. 2 is a side sectional view of the thin film forming apparatus.
[0021]
FIG. 3 is a cross-sectional view showing the internal configuration of the evaporation source in the present embodiment, FIG. 4A is a cross-sectional view showing the arrangement of the evaporation unit in the present embodiment, and FIG. It is the top view which looked at the arrangement configuration of a part from the downward direction.
[0022]
As shown in FIGS. 1 and 2, the thin film forming apparatus 1 of the present embodiment has a vacuum chamber 2 connected to a vacuum exhaust system (not shown), and an evaporation unit 3 described later is provided above the vacuum chamber 2. Is arranged.
[0023]
A shutter (not shown) for controlling the vapor evaporated from the evaporator 3 is provided near the lower part of the evaporator 3.
[0024]
On the other hand, a conveying means 4 such as a belt conveyor is provided in the lower part of the vacuum chamber 2, and a substrate (film formation target) 5 placed on the conveying means 4 is conveyed in the horizontal direction. (Conveying direction X).
[0025]
In this case, the transport direction X of the substrate 5 corresponds to the width direction of the host evaporation source 30 and the dopant evaporation source 31 described later.
[0026]
A mask 6 for defining a film formation region is provided near the upper side of the substrate 5, and this mask 6 is configured to be transferred together with the substrate 5 by the transfer means 4.
[0027]
On the other hand, the evaporation unit 3 includes a plurality of evaporation sources 30 and 31.
In the case of the present embodiment, it has a host evaporation source 30 for evaporating the host material and a dopant evaporation source 31 for evaporating the dopant material.
[0028]
The host evaporation source 30 and the dopant evaporation source 31 have elongate cylindrical evaporation containers 32 and 33, respectively.
[0029]
The evaporation containers 32 and 33 are made of a material having good thermal conductivity such as graphite, and the length thereof is set to be slightly longer than the substrate 5.
[0030]
Here, inside the evaporation vessel 32 of each host evaporation source 30, a predetermined organic evaporation material (for example, Alq3) 40 is accommodated in the accommodating portion 30a.
[0031]
As shown in FIGS. 4A and 4B, the host evaporation sources 30 are arranged in parallel at a predetermined pitch in the substrate transport direction X.
[0032]
Here, a plurality of evaporation ports 34 are linearly provided at predetermined intervals along the longitudinal direction of the central portion of the lower portion of the evaporation container 32 of each host evaporation source 30.
[0033]
In the case of the present embodiment, each evaporation port 34 is formed in a perfect circular shape having a predetermined size, and is straight in the width direction (arrow D direction) of the substrate 5 so as to face the substrate 5 immediately below the evaporation container 32. Are arranged.
[0034]
Further, the evaporation container 32 is provided with a heating means 42 for heating the evaporation material 40.
[0035]
The heating means 42 of the present embodiment has a main body portion 32a formed so as to surround the periphery of the evaporation container 32 except for portions other than the evaporation port 34 and the monitor evaporation port 36 described later, and this main body portion 32a. Inside, a filament (resistance heating type heater) 44 connected to the DC power source 43 is provided.
[0036]
Here, the main body portion 32a is made of a material having high thermal conductivity (for example, copper, Al, AlN, graphite, etc.), and is configured to heat the evaporation material 32 by heating the evaporation container 32 by the generated heat. .
[0037]
Further, in the case of the present embodiment, a cooling path 46 for circulating a refrigerant such as gas is disposed in the main body portion 32a, thereby controlling the main body portion 32a to a predetermined temperature. Yes.
[0038]
In the case of the present embodiment having such a configuration, the vapor of the evaporating material 40 is discharged vertically downward (in the direction of the arrow Y) from the evaporation port 34 provided in the lower part of the evaporation container 32.
[0039]
On the other hand, the dopant evaporation source 31 is disposed at a position adjacent to the host evaporation source 30, and is arranged in parallel at a predetermined pitch. A predetermined organic evaporation material (for example, DCJTB (4-dicyanomethylene-6-cp-julolidinostyryl-2-tert-butyl-4H-pyran), rubrene, etc.) is provided inside the evaporation vessel 33 of each dopant evaporation source 31. 41 is accommodated in the accommodating portion 31a.
[0040]
A plurality of evaporation ports 35 are linearly provided at predetermined intervals along the longitudinal direction of the central portion of the lower portion of the evaporation container 33 of each dopant evaporation source 31.
[0041]
In this case, each evaporation port 35 is formed in a circular shape with a predetermined size, and in the width direction of the substrate 5 (arrow D) so as to face the substrate 5 immediately below the evaporation container 33 as in the case of the host evaporation source 30. Direction).
[0042]
A heating unit 45 having the same configuration as that of the heating unit 42 described above is provided around the evaporation container 33, whereby the vapor of the evaporation material 41 is also discharged vertically downward (in the direction of arrow Y) from the evaporation port 34. It has come to be.
[0043]
Further, monitor evaporation ports 36 and 37 are provided at predetermined positions above the evaporation container 32 of the host evaporation source 30 and the evaporation container 33 of each dopant evaporation source 31, respectively.
[0044]
Further, film thickness sensors 38 and 39 for measuring the evaporation rates of the evaporation materials 40 and 41 are provided near the upper portions of the monitor evaporation ports 36 and 37 of the evaporation containers 32 and 33, respectively.
[0045]
In the case of forming a film on the substrate 5 in the present embodiment having such a configuration, after adjusting the inside of the vacuum chamber 2 to a predetermined pressure, the heating means 42 and 45 are closed with a shutter (not shown) closed. Driven to start heating the evaporation materials 40 and 41 in the host evaporation source 30 and the dopant evaporation source 31 of the evaporation unit 3.
[0046]
Thereby, the evaporation materials 40 and 41 are heated through the heated evaporation containers 32 and 33, and when the saturated vapor pressure is reached, the evaporation materials from the evaporation ports 34 and 35 of the respective host evaporation sources 30 and the dopant evaporation sources 31. 40 and 41 vapors are released.
[0047]
However, at this time, the vapors of the evaporation materials 40 and 41 are blocked by the shutter and do not reach the substrate 5.
[0048]
When the evaporation rate of the evaporation materials 40 and 41 reaches a predetermined value as measured by the film thickness sensors 38 and 39, the shutter is opened and the conveyance of the substrate 5 is started.
[0049]
As shown in FIG. 3, in the case of the present embodiment, the evaporation ports 34 and 35 are provided immediately below the evaporation containers 32 and 33, and the vapor of the evaporation materials 40 and 41 is almost from above the substrate 5. It reaches the substrate 5 vertically downward, that is, in a deposition down state.
[0050]
Then, film formation is performed for a predetermined time while the substrate 5 is being transported. When a desired film thickness is obtained, the shutter is closed and the film formation is completed.
[0051]
As described above, in the evaporation section 3 according to the present embodiment, the evaporation containers 32 and 33 are provided with the evaporation ports 34 and 35 for discharging the vapor of the evaporation materials 40 and 41 vertically downward. Vapor deposition can be performed in a so-called deposition down state with the substrate 5 facing down.
[0052]
As a result, according to the present embodiment, the mask 6 can be disposed on the substrate 5 to perform vapor deposition, so that the problem of mask distortion as in the prior art does not occur, and it is higher than that for a large substrate. An accurate pattern can be formed.
[0053]
Further, even when the substrate 5 is easily bent such as a film, a highly accurate pattern can be easily formed.
[0054]
Further, in the present embodiment, since the heating means 42 and 45 for heating the evaporation containers 32 and 33 are provided, the vapors of the evaporation materials 40 and 41 in the evaporation containers 32 and 33 are evaporated. Therefore, the vapor of the evaporation materials 40 and 41 can be efficiently discharged from the evaporation ports 34 and 35.
[0055]
In particular, in the case of the present embodiment, since the heating means 42 and 45 are provided around the evaporation containers 32 and 33, the evaporation materials 40 and 41 do not adhere to the heating means 42 and 45. The configuration of the evaporation containers 32 and 33 can be simplified.
[0056]
Furthermore, in the present embodiment, each of the evaporation containers 32 and 33 is formed in an elongated shape, and is moved relative to the substrate 5 in the width direction. In the case of vapor deposition, film formation with a uniform film thickness can be performed.
[0057]
In particular, in the case of the present embodiment, since the evaporation ports 34 and 35 are provided along the longitudinal direction of each of the evaporation containers 32 and 33, the film thickness can be made more uniform.
[0058]
In addition, in the present embodiment, monitor evaporation ports 36 and 37 are provided in the respective evaporation containers 32 and 33, and the evaporation rate is measured by the film thickness sensors 38 and 39. Therefore, the evaporation rate is always accurately measured. Is something that can be done.
[0059]
FIG. 5 is a schematic configuration diagram showing a main part of another embodiment of the present invention. The parts corresponding to those of the above embodiment are denoted by the same reference numerals and detailed description thereof is omitted.
[0060]
The evaporation section 3A of the present embodiment uses an induction heating type heater.
Here, the host evaporation source 30 will be described as an example. As shown in FIG. 5, a predetermined coil 50 is wound around the evaporation container 32, and an AC voltage having a predetermined frequency is applied from the AC power source 51 to the coil 50. It is comprised so that it may apply. This configuration can be similarly applied to the dopant evaporation source 31.
[0061]
In the present embodiment, for example, a cooling pipe (not shown) for circulating a refrigerant such as gas is wound around the evaporation containers 32 and 33 to control the evaporation containers 32 and 33 to a predetermined temperature. can do.
[0062]
According to the present embodiment having such a configuration, since the structure is simple, the heat capacity is small, and the structure can be cooled, it is possible to shorten the startup time and the fall time of the evaporation source 31. There is. Since other configurations and operational effects are the same as those of the above-described embodiment, detailed description thereof is omitted.
[0063]
FIG. 6 is a schematic configuration diagram showing the main part of still another embodiment of the present invention. The parts corresponding to those of the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0064]
As shown in FIG. 6, in the case of the evaporation unit 3B of the present embodiment, the host evaporation source 30 and the dopant evaporation source 31 that are the same as those of the above-described embodiment have a predetermined angle α of less than 90 degrees with respect to the horizontal direction. It is inclined and arranged.
[0065]
Further, the substrate 5 which is a film formation target is also transported together with the mask 6 by the transport means 4A inclined by a predetermined angle α of less than 90 degrees with respect to the horizontal direction.
[0066]
In this case, the transport direction of the substrate 5 is the width direction of the host evaporation source 30 and the dopant evaporation source 31 as in the case of the above-described embodiment.
[0067]
According to the present embodiment having such a configuration, the deposition is performed on the substrate 5 in a state where the substrate 5 is tilted by a predetermined angle α of less than 90 degrees with respect to the horizontal direction. There is an advantage that it is difficult to adhere. Since other configurations and operational effects are the same as those of the above-described embodiment, detailed description thereof is omitted.
[0068]
The present invention is not limited to the above-described embodiment, and various changes can be made.
For example, in the above-described embodiment, the substrate is moved with respect to the evaporation source, but it may be configured to move the evaporation source side.
[0069]
Further, the relative movement direction of the evaporation source and the substrate is not limited to one direction, and various movements such as reciprocal movement can be performed.
[0070]
Furthermore, in the above-described embodiment, the filament is embedded in the main body provided around the evaporation container. However, it is also possible to embed the filament directly in the evaporation container.
[0071]
However, in order to make the evaporation container simple, it is preferable to embed a filament in the main body provided around the evaporation container as in the above embodiment.
[0072]
Furthermore, in the above embodiment, the evaporation port is formed in a hole shape, but the present invention is not limited to this, and for example, it is formed in an elliptical shape, an oval shape, a polygonal shape, a cross shape, or a slit shape. It is also possible to do.
[0073]
Furthermore, the shape of the evaporation container is not limited to the cylindrical shape, and various shapes such as a box shape can be employed.
[0074]
In addition, the present invention can be applied not only to a vapor deposition apparatus for organic LED elements but also to various vapor deposition apparatuses, but is most effective when applied to a vapor deposition apparatus for organic LED elements.
[0075]
【The invention's effect】
As described above, according to the present invention, the problem of mask distortion does not occur, and a highly accurate pattern can be formed on a large film formation target.
Moreover, even when the film formation target is easily bent such as a film, a highly accurate pattern can be easily formed.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a preferred embodiment of a thin film forming apparatus according to the present invention. FIG. 2 is a side sectional view of the thin film forming apparatus. FIG. 3 shows an internal configuration of an evaporation source in the same embodiment. Sectional view [FIG. 4] (a): Cross-sectional view showing the arrangement of the evaporation section in the present embodiment (b): Plan view of the arrangement of the evaporation section viewed from below [FIG. 5] Other views of the present invention FIG. 6 is a schematic configuration diagram showing a main part of still another embodiment of the present invention. FIG. 7 is a diagram of a conventional thin film forming apparatus for producing an organic LED element. Schematic diagram [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Thin film formation apparatus 2 ... Vacuum chamber 3 ... Evaporation part 5 ... Substrate (film formation object) 30 ... Host evaporation source 31 ... Dopant evaporation source 32, 33 ... Evaporation container 34, 35 ... Evaporation port 36, 37 ... For monitoring Evaporating port 38, 39 ... Film thickness sensor 40, 41 ... Evaporating material 42, 45 ... Heating means

Claims (9)

A vacuum chamber;
An evaporation vessel provided in the vacuum chamber, having an elongated cylindrical shape and having an evaporation port at the bottom;
A storage portion provided in the evaporation container and storing the evaporation material;
Heating means for heating the evaporation container ;
Cooling means for cooling the evaporation container;
A thin film forming apparatus . The thin film forming apparatus according to claim 1, wherein the evaporation port is configured to discharge the evaporation material vertically downward. The thin film forming apparatus according to claim 2, wherein an evaporation port is provided along a longitudinal direction of the evaporation container. It said heating means, the thin film forming apparatus of any one of claims 1 to 3 is provided around the evaporation container. It said heating means, resistance heating type thin film forming apparatus of any one of claims 1 to 4 which is a heater. It said heating means, induction heating type thin film forming apparatus of any one of claims 1 to 5 is a heater. Wherein the evaporation vessel, a thin film forming apparatus of any one of claims 1 to 6 for monitoring the evaporation port is provided. The evaporating vessel, the thin film forming apparatus of any one of claims 1 to 7 is configured to move relative to the film-forming target. Moving direction of the evaporation vessel, the evaporating vessel thin film forming apparatus according to claim 8, wherein the width direction.

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