JP2006104524A - Crucible for vapor-depositing substrate to be treated for organic electroluminescence diode, vapor deposition system and vapor deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the reduction of reproducibility at the time of vapor deposition and the problem generated in an organic material. <P>SOLUTION: A crucible 12 for vapor deposition for vapor-depositing an organic layer onto a substrate to be treated for an organic electroluminescence diode is provided with: a bottom part 11 at which an organic material is arranged at the time of vapor deposition treatment; an opening part 13 from which the vaporized organic material is exhausted at the time of the vapor deposition; and at least one bent part 14 provided between the bottom part and the opening part in such a manner that the bottom part is not viewed from the opening part. Further, a vapor deposition system and a vapor deposition method are provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a crucible for vapor deposition of a substrate to be processed for an organic light emitting device, a vapor deposition apparatus, and a vapor deposition method.

  In recent years, the speed of information communication and the application range have been rapidly increasing. Among these, a high-definition display device capable of high-speed response with low power consumption capable of meeting demands such as portability and displaying moving images has been devised. In particular, organic light-emitting elements (referred to as organic electroluminescence and organic EL elements) have been published since 1987 when CWTang of Eastman Kodak Company announced a highly efficient organic EL element as a two-layer stacked device. Patent Document 1), various organic EL elements have been developed and partly put into practical use until now.

  The organic EL element is composed of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and the like including a light emitting layer, and these are composed of an organic layer made of an organic material (evaporation material). There are two types of materials for such an organic layer, a low molecular material and a high molecular material. In the case of an organic film using a low molecular material, it is mainly formed by vacuum deposition. A polymer material is dissolved in a solvent and used as a solution, and an organic film is formed mainly by a spin coater method, an ink jet method or the like.

  As a film formation method for an element having an organic compound thin film typified by an organic EL element, a heating vapor deposition method is adopted. Generally, an indirect heating method in which a material is contained in a crucible and heated from the outside with a heater or the like. Has been taken. FIG. 5 (a) shows a schematic perspective view of a first example of a conventional vapor deposition crucible. As shown in FIG. 5A, the conventional crucible 102 for vapor deposition has a cylindrical shape, and an organic material 101 to be vaporized can be introduced into the bottom thereof. In recent years, in order to improve the heat resistance of light emitting elements, organic materials for organic light emitting elements having a glass transition temperature of 80 ° C. or higher have been developed by various material manufacturers. These are intended to improve heat resistance, and it is said that the material characteristics at the time of vapor deposition are almost sublimable materials. In vapor deposition of such sublimable materials, the film thickness distribution depends on the material shape, crucible shape and material characteristics, and it is said that the reproducibility of the film thickness decreases with the consumption of the organic material.

  On the other hand, in recent years, as seen in Patent Document 1 and the like, there has been proposed an organic compound vapor deposition method in which a crucible is mixed with a ceramic or metal powder or pulverized material and heated to heat the crucible. According to this, it is said that the heat transferability in the container is improved, and it is possible to improve the decrease in the deposition rate and the decrease in the sublimation efficiency irrespective of the consumption amount of the material.

  However, with such a technique, the amount of the internal material decreases with the progress of vapor deposition, and the shape of the powder or pulverized product may be lost. In this case, the vapor flow density of the organic compound changes, suggesting the possibility that the film thickness distribution on the substrate changes.

  In addition, in order to maintain a stable vapor flow distribution regardless of the shape of the material in the crucible, a structure in which a shield plate is installed in the crucible so that the substrate to be processed cannot be seen directly from the top surface of the organic material is also proposed. Has been. FIG. 5B shows a schematic vertical cross-sectional view of a second example of a conventional vapor deposition crucible. As shown in FIG. 5B, the conventional evaporation crucible 202 has a cylindrical shape, and an organic material 201 to be vaporized can be introduced into the bottom thereof. The evaporation crucible 202 further includes first and second shielding plates 203 and 204. The first shielding plate 203 is provided in the opening of the evaporation crucible, has a shape that matches the shape of the opening, and has a smaller opening for the vaporized organic material to pass through in the center. Have. The second shielding plate 204 has an outer diameter smaller than the inner diameter of the vapor deposition crucible, and vapor deposition is performed via a support member provided between the lower surface of the second shielding plate and the bottom of the vapor deposition crucible. It is provided in the crucible for use. That is, the second shielding plate is a region where the organic material is charged so that the vaporized organic material is not directly discharged from the opening of the first shielding plate, that is, linearly, during the vapor deposition process. And provided between the opening of the first shielding plate.

  However, in such a technique, since the flow rate of the material evaporated as gas from the evaporation surface is limited by the shielding plate, it is necessary to keep the organic material at a higher temperature in order to reach a predetermined film forming speed. Become. That is, in the case of such a structure, in order to maintain a constant film forming speed, it is necessary to increase the temperature of the material at the time of vapor deposition as compared with the case where it is not shielded. However, increasing the material temperature unnecessarily increases the decomposition, polymerization and deterioration of the organic material which is an organic substance, and seriously damages the material. Moreover, in vapor deposition of a sublimable organic compound, there is a possibility that a deposit on the cluster is formed on the film forming surface due to the evaporation characteristics of the material. These are considered to be a source of an anode-cathode short circuit that greatly impairs the reliability of the device.

JP 2001-323367 A C.W.Tang, SA.VanSlyke, Appl.Phys.Lett.51,913 (1987)

  The present invention provides a crucible for use in an evaporation source capable of solving the above-described deterioration in reproducibility during vapor deposition and problems occurring in organic materials.

  According to one aspect of the present invention, there is provided a deposition crucible for depositing an organic layer on a substrate to be processed for an organic light emitting device, wherein a bottom portion on which an organic material is disposed during the deposition process, A crucible comprising an opening through which organic material vaporized at the time is discharged and at least one bent portion provided between the bottom and the opening so that the bottom cannot be seen from the opening Is provided. According to another aspect of the present invention, an apparatus for depositing an organic layer on a substrate to be processed for an organic light emitting device, for supporting a substrate to be processed provided in a vacuum chamber and the vacuum chamber. Temperature control for controlling the temperature of the crucible, which is provided adjacent to or close to the crucible, and the crucible provided to face the substrate to be processed in the vacuum chamber. An apparatus comprising the means. According to another aspect of the present invention, there is provided a method of depositing an organic layer on a substrate to be processed for an organic light emitting device, the step of disposing the substrate to be processed in a vacuum chamber so as to face a deposition source, Heating the crucible to vaporize the organic material and depositing on the substrate to be processed. According to another aspect of the present invention, there is provided an organic light emitting device obtained using the above-described vapor deposition method.

  As will be described in detail below, according to the present invention, it is possible to suppress the excessive temperature rise of the organic material during heating and perform the vapor deposition treatment without causing thermal damage to the material due to heating. Further, according to the present invention, it is possible to improve the film thickness reproducibility at the time of film formation without depending on the shape of the organic material, and as a result, it is possible to improve the characteristic reproducibility of the organic light emitting element. In addition, it is possible to reduce the probability of occurrence of a short circuit between the anode and the cathode in the device, and to achieve a large yield improvement. As described above, according to the present invention, a high-performance and highly reliable organic EL element can be manufactured.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

  As described above, the crucible for vapor deposition according to the present invention includes a bottom portion on which an organic material is disposed during the vapor deposition treatment, an opening through which the organic material vaporized during the vapor deposition treatment is discharged, and a bottom portion and an opening portion. And at least one bent portion provided between the two. The bottom, opening, and bent portion of the crucible can all have any cross-sectional shape, for example, a cross-sectional shape such as a circle, an ellipse, or a polygon such as a quadrangle. Moreover, it is preferable that an opening part is planar shape so that it can oppose in parallel with a to-be-processed substrate. Moreover, the bottom part can be made into arbitrary shapes, for example, can also be made into shapes, such as planar shape and curved surface shape. In particular, it is preferable that the bottom has a planar shape parallel to the opening. The bottom can be filled with an organic material through the opening, and as described below, from the outside of the crucible, by heating the bottom of the crucible, and if necessary, the opening and the bent portion of the crucible, The organic material put into the crucible can be vaporized and vapor deposition can be performed.

  The bent portion is provided between the bottom and the opening so that the bottom cannot be seen from the opening. In other words, the bent portion is provided between the bottom and the opening so that the organic material vaporized during the vapor deposition process cannot reach the opening linearly from the bottom. A plurality of bent portions can also be provided. When a plurality of bent portions are provided, if there is an evaporation source that could not be eliminated at one bent portion, the influence can be reduced.

  In FIG. 1, the typical perspective view of the crucible for vapor deposition concerning 1st embodiment of this invention is shown. As shown in FIG. 1, the crucible 12 for vapor deposition according to the first embodiment includes a bottom portion into which an organic material is charged during the vapor deposition process and an opening through which the organic material vaporized during the vapor deposition process is discharged. 13 and a bent portion 14 provided between the bottom and the opening. That is, the crucible is divided into an upper region on the opening side and a lower region 11 into which an organic material is introduced by the bent portion. In the first embodiment, the crucible has a dogleg shape. That is, the crucible has a linear upper region and a lower region, and is bent at an obtuse angle at the bent portion. By providing the bent portion in this manner, the bottom portion cannot be seen from the opening portion, and the organic material cannot reach the substrate to be processed linearly. The crucible has a circular cross section. The opening and bottom of the crucible are planar and parallel to each other. The crucible according to the first embodiment is particularly preferable in the following points. That is, since it has one bent portion, the deposition target substrate cannot be seen directly from the evaporation surface. Therefore, it is possible to control the clusters and splashes generated from the surface of the vapor deposition material when the temperature rises, and to reach the deposition substrate, and the change in the height of the evaporation surface caused by the material consumption It is preferable that the influence on the steam flow distribution can be reduced.

  FIG. 2 is a schematic perspective view of a vapor deposition crucible according to the second embodiment of the present invention. As shown in FIG. 2, the crucible 22 for vapor deposition concerning 2nd Embodiment is the bottom part into which an organic material is thrown in in the case of a vapor deposition process, and the opening part from which the organic material vaporized in the vapor deposition process is discharged | emitted 23, and a bent portion 24 provided between the bottom portion and the opening portion. In other words, the crucible is divided into an upper region on the opening side and a lower region 21 into which an organic material is introduced by the bent portion. In the second embodiment, the crucible has a shape having an arcuate detour. That is, the crucible has a linear upper region and a lower region, and has an arc-shaped detour for 180 ° as a bent portion between the upper region and the lower region. By providing the bent portion in this manner, the bottom portion cannot be seen from the opening portion, and the organic material cannot reach the substrate to be processed linearly. The crucible has a circular cross section. The opening and bottom of the crucible are planar and parallel to each other. The crucible according to the second embodiment is particularly preferable in the following points. That is, the crucible according to the second embodiment can accommodate more organic material without enlarging the crucible in the direction parallel to the substrate to be processed, as compared with the crucible according to the first embodiment. Easy to shape. Moreover, since it has the curved bending part, the possibility that a cluster or a splash can reach the film formation substrate is smaller than that in the first embodiment.

  FIG. 3 is a schematic perspective view of a vapor deposition crucible according to the third embodiment of the present invention. As shown in FIG. 3, the crucible 32 for vapor deposition according to the third embodiment includes a bottom portion into which an organic material is charged during the vapor deposition process, and an opening through which the organic material vaporized during the vapor deposition process is discharged. 33, and a bent portion 34 provided between the bottom portion and the opening portion. In other words, the crucible is divided into an upper region on the opening side and a lower region 31 into which an organic material is introduced by the bent portion. In the third embodiment, the crucible has a shape having a rotational detour. In other words, the crucible has a linear upper region and a lower region, and has a detour as a bent portion in which the flow path of the vaporized organic material rotates 360 ° between the upper region and the lower region. By providing the bent portion in this manner, the bottom portion cannot be seen from the opening portion, and the organic material cannot reach the substrate to be processed linearly. The crucible has a circular cross section. The opening and bottom of the crucible are planar and parallel to each other. The crucible according to the third embodiment is particularly preferable in the following points. That is, the crucible according to the second embodiment can accommodate more organic material without enlarging the crucible in the direction parallel to the substrate to be processed, as compared with the crucible according to the first embodiment. Easy to shape. Further, since the vapor flow is emitted through the opening by further rotating 360 °, the possibility of being affected by the evaporation surface is the lowest.

  Moreover, in this invention, the cross-sectional area of the area | region where the organic material vaporized in the vapor deposition process passes is preferably not smaller than the area where the organic material is disposed, and more preferably larger. In other words, the cross-sectional area of the tube defining the crucible is preferably larger or equal from the bottom of the crucible toward the opening. Specifically, the cross-sectional area of the region through which the vaporized organic material passes is preferably at least 1 time, preferably at most 3 times, more preferably at most 2 times the cross-sectional area of the region where the organic material is disposed. To do. More preferably, among the regions through which the organic material vaporized during the vapor deposition process passes, the cross-sectional area of the region closer to the opening is not smaller than, preferably larger than, the cross-sectional area closer to the bottom.

Assuming a general Knudsen cell, the number of evaporated molecules Je [molecules / m ² · s] passing through a unit area per unit time is expressed by the following equation. That is, it is an evaporation source used for MBE and the like, and is a system in which a resistance heating type heater is surrounded around the crucible. The molecule can be epitaxially grown on the substrate and is designed to stack atoms. The vapor flow and physical property values can be calculated theoretically and are the result of the calculation.

Je = (1/4) αnυ
= 2.6x10 ²⁴ p (MT) ^-1/2
(In the formula, T [K] represents temperature, p [Pa] represents pressure, n represents the number of molecules per unit volume, υ represents the average velocity of evaporated molecules, and M is Indicates the molecular weight of the evaporated molecule, α indicates the condensation coefficient.)

  Here, if the evaporation area of the crucible is S, the total number of evaporation atoms is JeS, and the total number of evaporation atoms is proportional to the evaporation area. However, under the above assumption, the ratio of the evaporation area and the area of the crucible opening is 1 (that is, the same area), and the vapor flow spreads from the crucible opening to the substrate to be processed from the crucible opening to the substrate. It is assumed that On the other hand, the film thickness distribution and reproducibility of the fully open evaporation source (crucible) as described above greatly depend on the shape of the crucible and the material shape. Has been.

  Therefore, as shown in FIGS. 1 to 3, in the crucible according to the present invention, the relationship between the evaporation area (S0), the cross-sectional area (S1) of the portion through which the steam flow passes, and the area (S2) of the opening. Preferably satisfies S0 ≦ S1 ≦ S2. Thus, by reducing the cross-sectional area of the region through which the vaporized organic material passes, smaller than the cross-sectional area of the region into which the organic material is introduced, the film thickness reproducibility is reduced even when the organic material is consumed. Without vapor deposition. Further, as will be described in detail below, a higher temperature is not required to ensure the film forming speed.

  As described above, the evaporation crucible according to the present invention is such that the substrate to be processed is not directly visible from the evaporation surface of the organic material, and preferably the area of the opening of the crucible and the region where the vapor passes through the crucible. The area is larger than the area of the steam generation surface. This crucible is characterized in that at least one bent portion exists between the bottom portion and the opening portion, and the substrate to be processed cannot be directly seen from the upper surface of the organic material. By this bent portion, the crucible is divided into a lower region in which the organic material for vapor deposition is stored and an upper region having an opening through which a vapor flow of the organic material is discharged to the substrate to be processed.

  When the crucible according to the present invention is installed in the evaporation source, the organic material put into the lower region is first heated, and a vapor flow of the organic material is generated. At this time, since the vapor flow generated in the lower region passes through the bent portion and is released to the outside of the crucible, the shape and amount of the organic material in the lower region can be obtained without providing a structure such as a shielding plate in the crucible. In addition, a stable vapor flow can be ensured regardless of the area. Further, since the vapor flow does not reach the substrate directly from the evaporation surface of the organic material, it is possible to suppress the arrival of the non-uniform cluster that is observed when the sublimable material is deposited on the substrate. Moreover, from the relationship between the evaporation area and the cross-sectional area through which the vapor flow passes, the vapor flow can be deposited on the substrate surface from the opening through the bent portion without being shielded at all. Further, since the cross-sectional area from the vapor deposition surface to the opening does not decrease, a higher temperature is not required to ensure the film forming speed, and it is possible to suppress degradation such as material decomposition and polymerization.

  The material for the crucible in the present invention is not particularly limited, but ceramics and metals can be used. Specifically, as the ceramic, metal oxide, metal nitride, carbide, carbon, such as aluminum nitride, silicon carbide, carbon, or the like can be used. Examples of metals that can be used include molybdenum, tantalum, and tungsten, which have a high melting point and high thermal conductivity. More specifically, the melting point of the metal used for the crucible is preferably 1000 ° C. or higher, and preferably 1500 ° C. or lower. Further, the thermal conductivity of the metal used for the crucible is preferably 100 W / mK or more, and preferably 500 W / mK or less.

  FIG. 4 is a schematic vertical sectional view of the vapor deposition apparatus according to the present invention. As shown in FIG. 4, the vapor deposition apparatus 40 includes a vacuum chamber 41, a vapor deposition source 42 provided in the vacuum chamber, a substrate support member 43 for supporting the substrate to be processed, and a substrate to be processed. A substrate support member, a crucible 44, and heaters (filaments) 45 and 46 are provided. A crucible 44 for charging an organic material (not shown) to be vaporized and filaments 45 and 46 as heaters for heating the crucible are stored in a storage case 42. The crucible 44 has heating filaments (heating wires) 45 and 46 connected to power sources 47 and 48 wound around the outer periphery, and the filaments 45 and 46 generate heat when energized to heat the crucible 44. . In this case, the filament is divided into an upper part and a lower part because temperature control at the top and bottom of the crucible can be performed individually. Further, an adhesion preventing plate 49 is provided on the inner side of the side wall of the vacuum chamber in order to prevent the organic material (deposition material) from contaminating the inner wall of the vacuum chamber. Further, the vacuum chamber is connected to an exhaust device (vacuum pump) 50 for decompressing the inside of the vacuum chamber.

  A substrate to be processed for the organic light emitting element is disposed at a predetermined position in such a vapor deposition apparatus, and the crucible in which the organic material to be vaporized is heated to vaporize the organic material, and the substrate to be processed is coated. It can be deposited on the treated surface. That is, the crucible 44 is charged with an organic material in the lower region and installed in the vapor deposition source. In the present invention, as the organic compound to be deposited, a sublimable material, a meltable material that vaporizes while melting, or the like can be used. In order to deposit an organic compound on the substrate 51, first, the vacuum pump 50 is operated to keep the inside of the vapor deposition apparatus 40 in a vacuum, and the filaments 45 and 46 are energized to heat the crucible 44. When the crucible 44 is heated, the internal organic material is heated as heat propagates from the inner wall of the crucible 44. When the organic material reaches a certain temperature, the organic compound powder is vaporized, and the vapor reaches the upper region of the crucible 44 through the bent portion of the crucible. Through these processes, a vapor flow is generated from the upper opening and adheres to the substrate 51 to form a thin film of organic material.

Note that the organic material to be a raw material is not particularly limited as long as it can be formed by a vapor deposition method, and various organic materials can be used. For example, π-electron conjugated organic semiconductor substances such as chain polymers such as polyacetylene and polyin, or molecular crystals of polyacenes (such as anthracene) and metal chelate compounds (such as copper phthalocyanine), anthracene, diethylamines, p-phenylenediamine, Compounds such as tetramethyl-p-phenylenediamine (TMPD) and tetrathiofulvalene (TTF) and acceptors such as tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE) and p-chloroanil Examples thereof include charge transfer complexes composed of compounds and the like, dye materials, fluorescent materials, liquid crystal materials, and the like. The vaporization temperature of these organic materials is 10 Pa to 10 ⁻⁷ Pa under atmospheric pressure during film formation, and is usually about 150 to 500 ° C., particularly preferably about 200 to 400 ° C.

  As described above, according to the present invention, since the organic material is contained in the crucible having the upper and lower two-layer structure divided by the bent portion, the distribution of the vapor flow density can be controlled regardless of the shape of the organic material. The reproducibility of the film thickness can be improved. Furthermore, since the vapor flow does not reach the substrate directly from the evaporation surface of the organic material, it is possible to suppress the non-uniform cluster reaching the substrate observed during the deposition of the sublimable material.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the examples described below.

[Example 1]
An organic material was charged into a crucible (see FIG. 1) according to the first embodiment, and a heating experiment was performed. The diameter of the bottom of the crucible was 3 cm, and the diameter of the opening was 6 cm. The material used is aluminum chelate (Alq3). Alq3 is a typical electron transporting material, and its characteristic is well known as sublimation. The temperature at which the Alq3 reached a film forming speed of 0.1 nm / sec was measured by inserting a thermocouple from the opening of the crucible. As a result, since the film forming speed reached 0.1 nm / sec at about 280 ° C., an organic thin film having a film thickness of 50 nm was formed on the glass substrate at the film forming speed 0.1 nm / sec. Thereafter, the surface shape (20 μm square) of the produced organic thin film was observed at three points (1-1, 1-2, 1-3) on the substrate by AFM. The results are shown in Table 1. As a result, it was found that a thin film with very few irregularities having a 10-point average roughness of 10 nm or less can be formed.

  Furthermore, using the evaporation source according to the present invention, the film thickness reproducibility by the number of times of film formation was also examined. As a result of examining the number of continuous film formation up to 20 times, it was found that high film thickness reproducibility was obtained.

  The average surface roughness, the maximum height difference, and the ten-point average roughness are used in the meaning commonly used by those skilled in the art. Specifically, the average surface roughness is also referred to as arithmetic average roughness, generally expressed as Ra, and is a value representing the arithmetic average in the target range of the absolute value of the roughness curve based on the center line. is there. The maximum height difference (Peak to Valley) is generally written as Rmax, and is a value representing the difference between the highest point and the lowest point. The ten-point average roughness is a value representing the difference between the average value of the altitude of the peak from the highest to the fifth and the average value of the altitude of the valley from the deepest to the fifth.

[Comparative Example 1]
On the glass substrate, the organic material thin film was formed with the crucible (refer FIG. 5A) according to what was mentioned above as a 1st example of the conventional crucible. The material used was an aluminum chelate (Alq3). This Alq3 was formed on a glass substrate with a film thickness of 0.1 nm / sec and a film thickness of 50 nm. The material temperature at a film forming rate of 0.1 nm / sec was about 280 ° C. Then, the surface shape of the organic thin film produced by AFM was observed. The results are shown in Table 2. As a result, it was found that the ten-point average roughness was remarkably larger than when the evaporation source according to the present invention was used. From these results, it was found that the surface of the thin film formed by the conventional evaporation source was a surface with considerably unevenness.

  Furthermore, using the crucible, the film thickness reproducibility by the number of times of film formation was also examined. It was found that high film thickness reproducibility can be obtained only up to about 5 times in continuous film formation.

[Comparative Example 2]
On the glass substrate, an organic material thin film was formed by an evaporation source shown in a crucible (see FIG. 5B) according to the above-described second example of the conventional crucible. The material used was an aluminum chelate (Alq3). This Alq3 was formed on a glass substrate with a film thickness of 0.1 nm / sec and a film thickness of 50 nm. The material temperature at a film forming rate of 0.1 nm / sec was about 310 ° C. A temperature higher by about 30 ° C. was required than when the crucible according to the present invention was used. Then, the surface shape of the organic thin film produced by AFM was observed. The results are shown in Table 3. As a result, it was found that a ten-point average roughness of 10 nm or less with a 10-point average roughness of 10 nm or less can be formed as in the case of using the evaporation source according to the present invention.

  Furthermore, using the crucible, the film thickness reproducibility by the number of times of film formation was also examined. As a result of examining the number of continuous film formation up to 20 times, it was found that high film thickness reproducibility was obtained.

[Example 2]
An organic material thin film was formed on a glass substrate with a crucible (see FIG. 2) according to the second embodiment. The diameter of the bottom of the crucible was 3 cm, and the diameter of the opening was 6 cm. The material used was an aluminum chelate (Alq3). This Alq3 was formed on a glass substrate with a film thickness of 0.1 nm / sec and a film thickness of 50 nm. The material temperature at a film forming rate of 0.1 nm / sec was about 280 ° C. as in Example 1. Then, the surface shape of the organic thin film produced by AFM was observed. The results are shown in Table 4. As a result, it was found that a ten-point average roughness of 10 nm or less with a 10-point average roughness of 10 nm or less can be formed as in the case of using the crucible in Example 1.

  Furthermore, using the crucible, the film thickness reproducibility by the number of times of film formation was also examined. Since the shape can accommodate more material than the crucible used in Example 1, it was found that high film thickness reproducibility was obtained even when the number of continuous film formation was examined up to 50 times.

In FIG. 1, the typical perspective view of the crucible for vapor deposition concerning 1st embodiment of this invention is shown. In FIG. 2, the typical perspective view of the crucible for vapor deposition concerning 2nd embodiment of this invention is shown. In FIG. 3, the typical perspective view of the crucible for vapor deposition concerning 3rd embodiment of this invention is shown. FIG. 4 is a schematic vertical sectional view of the vapor deposition apparatus according to the present invention. FIG. 5 (a) shows a schematic perspective view of a first example of a conventional vapor deposition crucible. FIG. 5B shows a schematic vertical cross-sectional view of a second example of a conventional vapor deposition crucible.

Explanation of symbols

11, 21, 31: Lower regions 12, 22, 32, 102, 202: Crucibles 13, 23, 33: Opening portions 14, 24, 34: Bending portions 40: Vapor deposition apparatus 41: Vacuum chamber 42: Storage case 43: Substrate Support member 44: crucible 45, 46: filament 47, 48: filament power supply 49: deposition plate 50: exhaust device (vacuum pump)
51: Substrate 101, 201: Organic material for vapor deposition 203, 204: Shield plate

Claims (9)

An evaporation crucible for depositing an organic layer on a substrate to be processed for an organic light emitting device,
A bottom where organic materials are arranged during the vapor deposition process;
An opening through which the organic material vaporized during the vapor deposition process is discharged;
A crucible comprising: at least one bent portion provided between the bottom and the opening so that the bottom cannot be seen from the opening.   The crucible according to claim 1, wherein the cross-sectional area of the region through which the organic material vaporized during the vapor deposition process passes is not smaller than the cross-sectional area of the region in which the organic material is disposed.   The crucible according to claim 1 or 2, comprising a plurality of the bent portions.   The crucible according to any one of claims 1 to 3, wherein a material of the crucible is ceramic or metal.   The crucible according to claim 4, wherein the ceramic is a metal oxide, metal nitride, carbide or carbon.   The crucible according to claim 4, wherein the melting point of the metal is 1000 ° C. or higher, and the thermal conductivity of the metal is 100 W / mK or higher. An apparatus for depositing an organic layer on a substrate to be processed for an organic light emitting device,
A vacuum chamber;
A substrate support member provided in the vacuum chamber for supporting the substrate to be processed;
The crucible according to any one of claims 1 to 6, which is provided in the vacuum chamber so as to face the substrate to be processed.
And a temperature control means for controlling the temperature of the crucible, which is provided adjacent to or close to the crucible. A method of depositing an organic layer on a substrate to be processed for an organic light emitting device,
Disposing a substrate to be processed in a vacuum chamber so as to face a deposition source;
Heating the crucible according to any one of claims 1 to 6 to vaporize the organic material and deposit it on the substrate to be processed.   The organic light emitting element obtained using the method of Claim 8.

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