JP2006120474A - Device and method for vapor-depositing organic layer on substrate for organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable vapor deposition on a large area without causing partial deterioration of a material, lowering of a yield, and a cost increase, when depositing an organic layer on a substrate to be processed for an organic electroluminescent element. <P>SOLUTION: This device is to deposit the organic layer on the substrate to be processed for the organic electroluminescent element, and is equipped with a vacuum chamber 10, a substrate supporting member to support the substrate to be processed, at least one vapor deposition source 12 provided facingly with the substrate to be processed in the vacuum chamber to dispose an organic material to be vaporized, and a plurality of temperature control means 13 each capable of independently controlling temperatures, which are provided adjacently or in close vicinity to the vapor deposition source, and can independently control each of the temperatures of a plurality of regions on the surface of the vapor deposition source facing the substrate to be processed by the temperature control of each of the temperature control means. This method is to deposit the organic layer on the substrate to be processed for the organic electroluminescent element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus and a method for depositing an organic layer on a substrate to be processed for an organic light emitting device.

  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 (also referred to as organic electroluminescence elements 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. 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 using the above-described low molecular weight organic material, a heating vapor deposition method is mainly employed. Generally, a material is accommodated in a crucible or the like, and a heater is used from outside An indirect heating method of heating is taken. In an organic EL mass production facility, the film thickness distribution is desired to be ± 5% or less from the center value within the film forming area. In response to such demands, a large area film forming technique is improved by using a method close to a point evaporation source or a method called a line source.

  On the other hand, it is indispensable to improve the utilization efficiency of the material for forming the light emitting layer of the organic EL element in order to reduce the cost of the panel. At present, when a point vapor deposition source is used, most of the vapor flow adheres to the side wall of the apparatus, and only a small amount of vapor is deposited on the film forming substrate. Therefore, the utilization efficiency is very low. For this reason, in the method called a line source as seen in Patent Document 1, the film forming substrate-deposition source distance is shortened and the film thickness distribution is good in the longitudinal direction. Is excellent in terms of.

JP 2003-7464 A C.W, Tang, S.A.VanSlyke, Appl.Phys.Lett.51,913 (1987)

  Depending on the nature of the organic material to be deposited, there are materials that sublime, and other materials that evaporate after being melted. For this reason, the heating method of the material is complicated, and particularly in the case of a sublimable material, the material in contact with the heated wall surface is preferentially vaporized, resulting in a change in the film thickness distribution. For this reason, a method of vapor deposition by vibrating the vapor deposition source itself has also been proposed. Each organic material applied to the organic EL element has a unique temperature-vapor pressure characteristic. In general, the temperature-vapor pressure characteristic of a sublimable material is said to be sensitive to temperature because the temperature range for obtaining the predetermined vapor flow is very narrow. The decomposition temperature and decomposition temperature of an organic material are determined by its molecular weight and molecular structure. Therefore, when heating an organic material at the time of vapor deposition, it is important that the temperature raising process is precisely controlled.

  FIG. 3 is a schematic cross-sectional view of a conventional line source type vapor deposition apparatus, taken along a vertical plane parallel to the line source. The vapor deposition apparatus includes a vacuum chamber 110, a substrate support member for supporting a substrate to be processed, a crucible (line source) 112 as a vapor deposition source, and a heater. A vapor deposition source (crucible) 112 for charging the organic material 126 to be vaporized and a heater (not shown) for heating the vapor deposition source are accommodated in a storage case 111. In addition, an adhesion preventing plate 115 is provided on the inner side of the side wall of the vacuum chamber 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 116 for decompressing the inside of the vacuum chamber. The heater is connected to a heater power source 117 and can be heated electrically. A film thickness measuring sensor 118 for measuring the film pressure of the deposited film is provided in the vacuum chamber, and the film thickness measuring sensor is connected to the film thickness measuring device 119. A substrate to be processed for an organic light emitting element is disposed at a predetermined position in such a vapor deposition apparatus, a vapor deposition source charged with an organic material to be vaporized is heated, the organic material is vaporized, and the substrate is processed. Can be evaporated. In FIG. 3, the vapor flow 114 of the organic material during the vapor deposition process is indicated by a broken line arrow.

  In order to vaporize the organic material having the above-described properties in the vapor deposition source 112 in a large area and uniformly, the temperature control is important. However, the larger the deposition source, the larger the heat capacity, and an enormous amount of time is required until soaking, and it becomes very difficult to uniformly control the temperature of the deposition source during film formation. Therefore, temperature distribution is likely to occur in the organic material housed around the vapor deposition source and in the vapor deposition source. As a result, a temperature difference occurs in the material in the vapor deposition source, and there is a high possibility that partial material deterioration will occur. This is one of the causes of yield reduction and cost increase.

  The problem to be solved by the present invention is to provide a line source capable of solving the above-mentioned problems occurring during mass production and capable of large-area deposition.

  According to one aspect of the present invention, an apparatus for depositing an organic layer on a substrate to be processed for an organic light emitting device, the vacuum chamber, and a substrate to be processed provided in the vacuum chamber for supporting the substrate to be processed A substrate supporting member, at least one vapor deposition source for disposing an organic material to be vaporized disposed in the vacuum chamber so as to oppose the substrate to be processed, and adjacent to or in proximity to the vapor deposition source A plurality of temperature control means that can be independently temperature controlled, and each of the plurality of regions on the surface of the vapor deposition source facing the substrate to be processed is controlled by each temperature control of the temperature control means; There is provided an apparatus comprising temperature control means that enables temperature control independently. 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 so as to face a deposition source in a vacuum chamber; And a method of independently temperature-controlling a plurality of regions on the surface of the vapor deposition source facing the substrate, vaporizing the organic material in each of the regions, and depositing the vapor on the substrate. Is provided. Moreover, according to the other aspect of this invention, the organic light emitting element obtained using the said vapor deposition method is provided.

  As described in detail below, according to the present invention, in one vapor deposition source, in order to suppress thermal interference from adjacent temperature control means, each temperature control means is thermally independent, Controllability is high, and excessive temperature rise during temperature rise can be suppressed. For this reason, according to the present invention, it is possible to control the deposition rate and suppress the change in the film thickness distribution without causing thermal damage to the organic material, and on the organic light emitting device substrate having a low cost and a high yield. An apparatus and a method for depositing an organic layer on the substrate can be realized.

  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 vapor deposition apparatus according to the present invention includes a vacuum chamber, a substrate support member provided in the vacuum chamber for supporting the substrate to be processed, and the substrate to be processed in the vacuum chamber. It is provided with at least one vapor deposition source for disposing an organic material to be vaporized and a plurality of temperature control means provided adjacent to or in proximity to the vapor deposition source. The vapor deposition apparatus preferably includes a storage case for storing the vapor deposition source and the temperature control means. The temperature control means is capable of independently controlling the temperature, whereby the plurality of regions on the surface of the vapor deposition source facing the substrate to be processed are independently temperature controlled by the temperature control of each temperature control means. Make it possible.

  The vapor deposition source is not particularly limited, and a vapor deposition source having a size sufficient for vapor deposition on the target substrate for the target organic light emitting element is used. Here, as described in Patent Document 1, by using a movable vapor deposition source, it is possible to use a vapor deposition source that is smaller than the size of the target substrate to be processed (processed area). The vapor deposition source may have an arbitrary shape, for example, a one-dimensional linear shape called a line source, or a two-dimensional planar shape. When a linear deposition source is used, the temperature control means can be arranged in a line in the longitudinal direction of the deposition source, and in this case, the temperature controllable region faces the substrate to be processed of the deposition source. In the plane, they exist side by side in the longitudinal direction of the vapor deposition source. In the case where a planar deposition source is used, the temperature control means can be arranged two-dimensionally, and in this case, the temperature controllable region is on the surface of the deposition source facing the substrate to be processed. It exists side by side in a two-dimensional manner in a direction parallel to the processing surface.

  As the temperature control means, a heater capable of heating the vapor deposition source and a cooling means capable of cooling the vapor deposition source can be used. That is, in order to vaporize the organic material, it is necessary that each vapor deposition source is adjacent to or close to at least one heater. However, in order to control the temperature more precisely, cooling means can be further used. . The heater is not particularly limited, and for example, a heater that is connected to a heater power source and can be heated by energization can be used. The cooling means is not particularly limited. For example, the cooling source can be cooled by providing a cooling pipe adjacent to or in proximity to the vapor deposition source and flowing a cooling fluid or a cooling gas therein.

  In the first embodiment, the vapor deposition apparatus includes a plurality of vapor deposition sources, and at least one vapor deposition source is provided so that the plurality of vapor deposition sources can be independently controlled in temperature. Temperature control means are provided. FIG. 1 is a schematic cross-sectional view of a line source type vapor deposition apparatus according to a first embodiment of the present invention, taken along a vertical plane parallel to the line source. As shown in FIG. 1, in the vapor deposition apparatus according to the first embodiment, a plurality of cylindrical vapor deposition sources (line sources) 12 having an open top are arranged in a vacuum chamber 10. An organic material (not shown) is put into the bottom of the plate. Further, two heaters 13 are provided for each vapor deposition source. The two heaters are provided such that the bottom or top of the vapor deposition source can be independently temperature controlled. Thus, the heaters that are thermally independent from each other are arranged in the longitudinal direction of the line source. Thus, each heater can control the temperature of only one vapor deposition source without substantially affecting the heater provided in the adjacent vapor deposition source. That is, in the first embodiment, each of the regions inside each vapor deposition source is independently temperature controlled. In FIG. 1, the vapor flow 14 of the organic material during the vapor deposition process is indicated by a broken line arrow.

  According to the present invention, it becomes possible to control the temperature distribution that is likely to occur particularly in the longitudinal direction by individual heaters, and the temperature gradient can be relaxed. As a result, the vapor flow density near the center of the storage case and the vicinity of the end in the longitudinal direction can be easily leveled, and the film forming speed on the entire surface of the substrate to be processed can be easily leveled. Moreover, since temperature control can be performed precisely, excessive temperature rise can be suppressed and material deterioration due to temperature can be reduced.

  Further, according to the first embodiment, it is possible to particularly reduce mutual thermal interference by separating adjacent heaters. Further, according to the first embodiment, by providing a plurality of vapor deposition sources, the heat capacity of the vapor deposition source and the organic material put into the vapor deposition source can be further reduced as compared with the case of using one vapor deposition source. it can. By reducing the heat capacity in this way, responsiveness can be improved, and temperature control by a heater or the like can be made more precise.

  That is, especially in the line source, the length ratio differs greatly between the longitudinal direction and the depth direction. For this reason, it is important to reduce the temperature difference generated in the longitudinal direction rather than the temperature difference generated in the depth direction. However, as described above, in the conventional structure in which the vapor deposition source is integrated and the integral heater is provided in the longitudinal direction, the temperature of the central portion tends to increase easily at the vapor deposition source end and center. . This is because heat is easily generated in the center and is greatly affected by the heater. For this reason, as described above, for example, by providing a heater for each of a plurality of vapor deposition sources, a temperature difference in the longitudinal direction can be reduced by providing a plurality of regions in which the temperature can be independently controlled. It becomes possible.

  In addition, as described above, in the conventional line source type vapor deposition apparatus, a temperature difference is likely to occur between the central portion and the end portion. That is, the temperature rises near the center and the temperature tends to fall near the end. In this case, a temperature difference also occurs between the central portion and the end portion of the organic material in the vapor deposition source. Generally, when vapor-depositing an organic material, the vapor flow density corresponds to the vapor pressure curve of the organic material. The vapor pressure of organic materials is specific to temperature. In particular, recent organic EL materials have been made higher in polymer and higher in Tg in order to improve device reliability and heat resistance. The vapor pressure characteristics for are very sensitive. For this reason, it goes without saying that uniform temperature is very important in order to equalize the film forming speed in the longitudinal direction.

  Here, the excessive temperature rise means that the vapor deposition source is heated with a heater, and when the temperature is raised, the temperature is raised to a temperature higher than the temperature range to be controlled due to its heat capacity, responsiveness, etc. To reach. In the case of a good temperature profile, the temperature is controlled at a substantially predetermined temperature after the temperature rise. On the other hand, in the case of an excessive temperature rise, the temperature is lowered, for example, by several tens of degrees. In the case of organic materials, this difference of several tens of degrees can cause fatal damage to the material. In particular, when heating a large source such as a line source, it is easy to obtain a profile with an excessive temperature rise as described above. This is thought to be due to the large heat capacity and heat conduction problems. In the case of a line source having a plurality of regions which are thermally separated and can be independently controlled as in the present invention, it is possible to obtain an ideal profile without excessive temperature rise.

  Further, when the heaters are completely separated as in the first embodiment, there is almost no thermal interference between the heaters. This is because the heater is installed in a high vacuum chamber that hardly conducts heat between adjacent heaters. On the other hand, in a conventional vapor deposition apparatus in which a vapor deposition source that is a line source is integrated, and an integrated heater is provided in the longitudinal direction, if the temperature of the vapor deposition source is controlled by the heater, the entire vapor deposition source Similarly, the temperature is subject to temperature adjustment. In particular, when the structure around the heater is a highly heat-resistant metal, such as Mo, W, or SUS, the ambient temperature is easily affected by the heat from the heater. As described above, in the present invention, the heater controlled to a predetermined temperature does not thermally interfere with other adjacent heaters, and thereby temperature adjustment for keeping the vapor flow density of the material to be vaporized constant. Is possible.

  In addition, the time required for the evaporation source and the organic material to reach a predetermined temperature and become constant is considerably long because the charge amount of the organic material and the heat capacity of the line source increase in the conventional line source. It was. However, in the vapor deposition apparatus according to the first embodiment, the temperature of the crucible and the shielding plate described below can be individually controlled, and can reach a predetermined temperature in a relatively short time compared to the conventional case. Is possible.

  The vapor deposition apparatus according to the second embodiment based on the present invention has a vapor deposition source and a structure of temperature control means different from those of the first embodiment. That is, in the first embodiment, the vapor deposition source and the heater are both thermally separated. On the other hand, in the second embodiment, a plurality of temperature control means are provided adjacent to or close to one of the vapor deposition sources. That is, the vapor deposition apparatus includes a plurality of temperature control means provided adjacent to or in proximity to any one of the vapor deposition sources. Here, it is preferable that the vapor deposition apparatus further includes a temperature control plate. The temperature control plate has a plurality of temperature control parts for arranging the temperature control means and at least one connecting part. Here, a connection area | region connects between temperature control parts, and a heat conduction characteristic is smaller than a temperature control part. The temperature control plate is provided between the vapor deposition source and the temperature control means so that the plurality of temperature control units are adjacent to or close to at least one of the vapor deposition sources, and the temperature control means is further interposed via the temperature control plate. In order to control the temperature of the vapor deposition source, it is provided adjacent to or close to each of the temperature control units. By providing the temperature control plate in this way, even when the vapor deposition source is integrated, it is possible to level the temperature gradient that tends to occur in the longitudinal direction by performing independent control. For this reason, it is possible to prevent overheating, and in the case of a monolithic object, it is possible to improve the point that the central portion tends to become high temperature, and to reduce thermal damage to the organic material that is the deposit.

  FIG. 2 shows a schematic diagram of a temperature control plate according to the second embodiment. As shown in FIG. 2, in the second embodiment, the vapor deposition source is an integrated object. A cut is provided in one temperature control plate 25, and a heater 24 is provided in each of the areas partitioned by the cut. In other words, in the second embodiment, as shown in FIG. 2, an independent heater is attached to a single temperature control plate, and a notch is provided between the heaters of the temperature control plate. It is possible to reduce the thermal influence between adjacent heaters as much as possible. Although not particularly limited, each of the temperature control unit and the connection unit may have a quadrangular shape. That is, the rectangular temperature control plate can be provided with a rectangular cut in a direction perpendicular to the longitudinal direction at a predetermined interval in the longitudinal direction. Moreover, the length of the temperature control part and the connection part in the longitudinal direction of the temperature control plate can be appropriately set according to the superheating efficiency of the vapor deposition source, the thermal influence between adjacent heaters, and the like.

  In this way, by providing a cut in the temperature control plate, the region with the cut can be a connecting portion having a smaller thermal conductivity than the region where the heater without the cut is provided (temperature control unit), Instead of providing the notches, the connecting portion can be provided using a material having low thermal conductivity. In this way, heat conduction between heaters can be hindered, and the thermal influence between adjacent heaters can be mitigated. Although not particularly limited, Mo, Cu, Ta, or the like having high thermal conductivity can be used as the temperature control plate material. In particular, when a material having low thermal conductivity is used for the connecting portion, a metal having low thermal conductivity such as SUS301 can be used.

  As described above, in the second embodiment, by making a notch between adjacent heaters, it is possible to cut off part of the heat flow and independently control the temperature of each heater. In this case, since it is necessary for the depth of the cut not to reduce the strength of the temperature control plate, when the width of the temperature control plate is L, the width of the connecting portion is optimally about L / 10 to L / 5. Yes, but not necessarily in this range.

  In addition, it is preferable that a vapor deposition apparatus is further provided with the temperature-controllable shielding board for disperse | distributing the vaporized organic material provided between the vapor deposition source and the area | region where a to-be-processed substrate is distribute | arranged. With the shielding plate, the vapor flow of the supplied organic material can be controlled, and the vapor of the organic material is uniformly distributed to the substrate to be processed. In other words, the shielding plate is a structure for supplying vaporized organic material to the inside or the bottom of the shielding plate and distributing the vapor uniformly without being biased over the entire surface of the substrate installed on the top. The shielding plate may be a plate or a structure that can shield and distribute the vapor. The shape and size are not particularly limited, and may be an appropriate shape and size as necessary. For example, a lattice-shaped plate, a plate having a plurality of holes for allowing the vaporized organic material to pass through, or the like can be used. In addition, the material is not particularly limited, but it is a substance that does not react or bond with a raw material organic material such as a metal such as SUS, Cu, Ta, or Mo, or a ceramic such as alumina, zirconia, or aluminum nitride. It is necessary to be. Cu, Mo and the like having good thermal conductivity are preferable.

  In this way, when the organic material thrown into the vapor deposition source is heated in a vacuum chamber and deposited on the substrate using a shielding plate, the design of a line source with a high degree of freedom regardless of sublimation or melting material Is possible. In other words, by providing a shielding plate that can control the temperature of the organic material independently before the organic material is deposited on the substrate, there is no need to consider changes in the vaporization surface of the organic material, and it can be used many times during mass production. However, there is little fluctuation in film thickness distribution and rate, and control during film formation becomes easy.

  In addition, in order to prevent an organic material from contaminating the inner wall of a vacuum chamber, the adhesion prevention board can be provided inside the side wall of the vacuum chamber of the vapor deposition apparatus concerning this invention. Furthermore, the vacuum chamber is preferably connected to an exhaust device for reducing the pressure inside. In addition, a film thickness measurement sensor connected to a film thickness meter can be provided in the vacuum chamber in order to measure the film pressure of the deposited film.

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.

  By supporting the substrate to be processed so as to face the vapor deposition source by the substrate support member, the substrate to be processed is arranged in the vapor deposition apparatus so as to face the vapor deposition source, and the vapor deposition source into which the organic material to be vaporized is charged By heating, the organic material can be vaporized and deposited on the substrate to be processed. At this time, the temperature of each of the plurality of regions on the surface of the evaporation source facing the substrate to be processed is independently controlled, and the organic material is vaporized in each of these regions to be deposited on the substrate to be processed.

  Here, the temperature control of each region, that is, the temperature control of each temperature control means can be performed as follows, for example. That is, until the temperature before the organic material is heated and vaporized, the temperature of each crucible is measured and controlled by the PID of the heater. Thereafter, when each crucible reaches a predetermined temperature, feedback control from the film thickness meter is performed to control the steam flow.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, it should be understood that these examples do not limit the present invention and can be variously modified without departing from the gist of the present invention.

[Example 1]
As the vapor deposition apparatus according to the example, the one according to the vapor deposition apparatus shown in FIG. 1 was used. Specifically, a set of 10 heaters and vapor deposition sources was installed in a 700 mm long storage case, and a demonstration test on the stability of the film forming speed was performed. More specifically, the vapor deposition apparatus according to the embodiment includes a vacuum chamber, a substrate support member for supporting a substrate to be processed, a crucible (line source) as a vapor deposition source, and a heater. In a storage case 11 provided in the vacuum chamber 10, a plurality of cylindrical vapor deposition sources 12 having an open top are arranged, and two heaters 13 are provided for each of the vapor deposition sources. Further, an adhesion preventing plate 15 is provided inside the side wall of the vacuum chamber in order to prevent an organic material (evaporation material) from contaminating the inner wall of the vacuum chamber. Further, the vacuum chamber is connected to an exhaust device 16 for decompressing the inside of the vacuum chamber. The heater is connected to a heater power source 17 and can be heated electrically. A film thickness measurement sensor 18 for measuring the film pressure of the deposited film is provided in the vacuum chamber, and the film thickness measurement sensor is connected to the film thickness meter 19. Further, a temperature-controllable shielding plate 22 connected to the shielding plate heater power source 21 is provided between the line source 11 and the region where the substrate 20 to be processed is installed.

  Aluminum chelate (Alq3) was used as the organic material. Alq3 is a typical electron transporting material, and its characteristic is well known as sublimation. The controllability and the temperature rising process when this Alq3 was deposited at a film forming rate of 10 nm / sec were verified. Note that 10 g of the organic material was added to each of the ten vapor deposition sources to make a total of 100 g.

  First, the temperature of the shielding plate was set to 350 ° C. Thereafter, the evaporation source at the material introduction part was heated to evaporate Alq3 and deposit it on the substrate. The temperature of the organic material at that time was 320 ° C. At this time, it took about 30 minutes from the start of the temperature rise of the shielding plate until each part and material were heated and the organic material reached a predetermined film-forming speed. Further, the amount of the organic material consumed in the temperature raising process was 1 g or less.

[Comparative Example 1]
As a vapor deposition apparatus according to the comparative example, a conventional vapor deposition apparatus was used, and a verification test on the stability of the film forming speed was performed. The experiment was performed under substantially the same conditions as in the example except that the vapor deposition source as a line source was an integral object and an integral heater was provided in the longitudinal direction.

  As a result, the time from when the temperature of the shielding plate was started to when each part and material were heated and the organic material reached a predetermined film forming speed was about 5 hours. In addition, the total amount of organic materials consumed in the temperature raising process reached several tens of grams.

[Example 2]
An organic material thin film was formed on the glass substrate by the vapor deposition apparatus according to the above example. The material used was an aluminum chelate (Alq). Alq is a typical electron transporting material, and its characteristic is well known as sublimation. This Alq was formed on a glass substrate set at a film forming speed of 10 nm / sec and a film thickness of 300 nm in a range of 770 mm × 150 mm.

  Here, the temperature control of each temperature control means was performed as follows. First, the temperature of each crucible was measured and controlled by the PID of the heater until the temperature before the organic material was heated and vaporized. Thereafter, when each crucible reached a predetermined temperature, feedback control from the film thickness meter was performed to control the steam flow.

  Then, the film thickness of the produced organic thin film was measured with the stylus type film thickness meter. As a result, it was found that a thin film having a uniform film thickness with a relatively small film thickness distribution of 0.9 [−] or more in all glass substrates can be formed. At this time, a temperature distribution of about 5 to 10 ° C. occurred in the longitudinal direction of the line source. In addition, the said film thickness is a relative film thickness, and means the ratio with respect to the film thickness, assuming the maximum film thickness in the plane as 1. For this reason, the unit of the film thickness is a dimensionless [-].

  Furthermore, using the vapor deposition apparatus according to the present invention, the film thickness reproducibility at a plurality of times of film formation was also examined. As a result of examining the number of continuous film formation up to 50 times, it was found that high film thickness reproducibility was obtained.

[Comparative Example 2]
The organic material thin film was formed on the glass substrate with the vapor deposition apparatus concerning the said comparative example. The materials and film forming conditions were the same as in Example 2. The film was formed on a glass substrate with a film forming speed of 10 nm / sec and a film thickness of 300 nm set in a range of 770 mm × 150 mm. Then, the film thickness of the organic thin film produced with the stylus type film thickness meter was measured. As a result, it was found that the relative film thickness had a large film thickness distribution of 0.8 [−] or less. It has also been found that this is due to a temperature distribution of about 10 to 30 ° C. with respect to the longitudinal direction of the line source. Moreover, it is estimated that there is also a thermal damage regarding the organic material in each temperature range.

  Furthermore, the film thickness reproducibility by the number of times of film formation was also examined using the vapor deposition apparatus according to the comparative example. It was found that high film thickness reproducibility can be obtained only up to about 10 times in continuous film formation.

[Example 3]
Further, an attempt was made to produce an organic EL element using the vapor deposition apparatus according to the above example. As the substrate, glass with 50 mm × 50 mm ITO was used in a range of 770 mm × 150 mm.

  The structure of the fabricated device was hole transport layer / light emitting layer / electron injection layer / cathode. A 40 nm α-NPD was used for the hole transport layer, and Alq 3 of 60 nm was used for the light emitting layer (also serving as the electron transport layer). The film forming speed was 2 nm / sec, and the films were formed in order in each film forming chamber. Next, 100 nm of Ag—Mg was stacked as an electron injection layer and a cathode.

  As a result of evaluating the device thus fabricated, the average current efficiency of the device was 4 cd / A, and the variation was within ± 10%.

[Comparative Example 3]
Next, production of an organic EL element was attempted in the same manner as in Example 3 using the vapor deposition apparatus according to the comparative example. As a result of evaluating the device thus fabricated, it was found that the device had substantially the same efficiency as that of Example 3.

  However, the variation was as large as ± 20%. As described in Comparative Example 2, the cause of the variation was considered to be largely due to the film thickness distribution of the element.

FIG. 1 is a schematic cross-sectional view of a line source type vapor deposition apparatus according to a first embodiment of the present invention, taken along a vertical plane parallel to the line source. FIG. 2 shows a schematic diagram of a temperature control plate according to the second embodiment. FIG. 3 is a schematic cross-sectional view of a conventional line source type vapor deposition apparatus, taken along a vertical plane parallel to the line source.

Explanation of symbols

10, 110: Vacuum chamber 11, 111: Storage case 12, 112: Evaporation source 13: Heater 14, 114: Vapor flow 15, 115: Deposition plate 16, 116: Exhaust device 17, 117: Heater power supply 18, 118 : Film thickness measuring sensor 19, 119: Film thickness measuring meter 20: Substrate 21: Shield plate heater power supply 22: Shield plate 24: Heater 25: Temperature control plate 126: Organic material

Claims (7)

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;
At least one vapor deposition source for disposing an organic material to be vaporized provided in the vacuum chamber so as to face the substrate to be processed;
A plurality of temperature control means, which are provided adjacent to or in the vicinity of the vapor deposition source and each of which is capable of independently controlling the temperature, are opposed to the substrate to be processed of the vapor deposition source by the temperature control of each of the temperature control means. And a temperature control means for enabling temperature control of a plurality of regions on the surface to be independently controlled.   The apparatus includes a plurality of vapor deposition sources, and at least one temperature control unit is provided for each of the vapor deposition sources so that the plurality of vapor deposition sources can be independently controlled in temperature. Item 2. The apparatus according to Item 1.   The apparatus according to claim 1, wherein a plurality of the temperature control means are provided adjacent to or close to one of the vapor deposition sources. A temperature control plate having a plurality of temperature control units for arranging the temperature control means and at least one connection unit that connects between the temperature control units and has a heat conduction characteristic smaller than that of the temperature control unit. A temperature control plate provided between the vapor deposition source and the temperature control means so that a plurality of the temperature control units are adjacent to or close to one of the vapor deposition sources,
The apparatus according to claim 3, wherein the temperature control means is provided adjacent to or in proximity to each of the temperature control units so that the temperature of the vapor deposition source can be controlled via the temperature control plate.   The temperature-controllable shielding board for disperse | distributing the vaporized organic material provided between the said vapor deposition source and the area | region where the said to-be-processed substrate is distribute | arranged is further provided. The device described in 1. 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;
A plurality of regions on a surface of the vapor deposition source facing the substrate to be processed, each of which independently controls the temperature, vaporizing the organic material in each of the regions, and depositing the vapor on the substrate to be processed.   The organic light emitting element obtained using the method of Claim 6.

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