JP4862295B2 - Method and apparatus for manufacturing organic EL element - Google Patents

Description

  The present invention relates to a technique for manufacturing an organic EL element by forming an organic EL film by vapor deposition.

  An organic EL element (organic electroluminescent element) is formed by laminating organic EL films such as an anode layer, an organic light emitting layer, and a cathode layer on the surface of a substrate such as a transparent glass plate (see FIG. 5 described later). ). As one method for producing an organic EL element, a vapor deposition method is known in which these organic EL films are formed on a substrate by vapor deposition. In the vapor deposition method, in general, a substrate is placed facing an evaporation source in a chamber, the evaporation source is heated in a state where the pressure in the chamber is reduced, and the evaporation material of the evaporation source is vaporized. In this method, the film is deposited on the surface (see, for example, Patent Document 1).

  In producing an organic EL element by forming an organic EL film by vapor deposition in this way, in order to produce the organic EL element with good reproducibility, the reproducibility of the deposited film thickness of the organic EL film is sufficiently controlled. It is necessary to form a film with a certain film thickness. In general, a film thickness meter using a crystal resonator is used as a film thickness measuring means in the vapor deposition apparatus, and an organic EL film having a predetermined film thickness is formed at a high rate within a range that does not affect element characteristics. This is necessary for productivity.

  The reproducibility of the film thickness of the organic EL film is required to be more severe with the recent change in the element structure of the organic EL element. In particular, in an element having a light-emitting layer thinner than a conventional element, an element having a plurality of light-emitting layers, etc., the effect of the film thickness deviation on the element characteristics is larger than in the case of a conventional element. Therefore, the reproducibility of the film thickness is strictly required.

  Here, in the weight-film thickness conversion method generally measured using a crystal oscillator thickness meter, a required film weight-film thickness conversion coefficient is determined in advance, and the film is determined from the amount deposited on the crystal oscillator. The thickness conversion value is read. This conversion factor is, for example, a slight shift in the position of the crystal resonator, the dependency of the evaporation flow pattern on the amount of remaining material in the evaporation source, the thermal change in the crystal resonator characteristics, the crystal resonator Since it is affected by temporal changes and lifespans of the characteristics, care must be taken in its management, and the possibility that the actual film thickness has shifted cannot be denied. The film thickness quantification method using a quartz oscillator film thickness meter is generally used because its principle is simple, but considering such problems, it is not necessarily optimal for strict film thickness reproducibility. Absent.

In addition, film formation at a higher evaporation rate has been required from the viewpoint of shortening manufacturing time for improving productivity. However, as the evaporation rate increases, fluctuations in the evaporation rate and subtle changes in the deposition time tend to appear as film thickness deviations. In this case, more precise film thickness management is required. For example, when forming a film with a thickness of 200 nm, if the deposition is performed at a high deposition rate of 20 nm / s, the deposition time is as short as 10 seconds, but the film is deposited when the deposition time is shifted by 0.5 seconds. The thickness deviation reaches 10 nm. On the other hand, when the film is formed at a low film formation rate of 1 nm / s, the vapor deposition time is as long as 200 seconds, but the deviation of the vapor deposition time of 0.5 seconds is only a film thickness deviation of 0.5 nm. Don't give. As described above, the deposition time can be shortened at a high rate, but a time error that does not cause a problem in the case of a low rate deposition appears as a very large film thickness deviation during the deposition at a high rate. Is. In addition, since the life of a crystal resonator that measures the rate is shortened at the time of high rate evaporation, a measure such as a plurality of crystal resonators and switching at predetermined intervals is required more strongly.
JP 2002-80961 A

  The present invention has been made in view of the above points. In forming an organic EL film by vapor deposition, the vapor deposition time can be shortened, and at the same time, the film thickness can be secured with high reproducibility. It aims at providing the manufacturing method and manufacturing apparatus of an organic EL element which can be performed.

The manufacturing method of the organic EL element of the present invention is an evaporation source having a high evaporation rate as an evaporation source made of the same evaporation material when an organic EL light emitting element is manufactured by depositing an organic EL film material to form a film. And an evaporation source having a low evaporation rate, and an evaporation source having a low evaporation rate is formed by an evaporation flow from an evaporation source having a high evaporation rate. The material was deposited to a target film thickness or less, and at the same time as the deposition at the high evaporation rate, the film for film thickness evaluation was deposited with the deposition material, and the film thickness of the film for film thickness evaluation was measured. Then, based on the film thickness measurement result of the film for film thickness evaluation, the film is formed by depositing the deposition material from the evaporation source having a low evaporation rate to the target film thickness at a low evaporation rate. To do

The organic EL element manufacturing apparatus of the present invention is an apparatus for manufacturing an organic EL light-emitting element by depositing and depositing an organic EL film material, and has a film thickness equal to or less than a target film thickness at a high evaporation rate. Measure the film thickness of the evaporation source having a high evaporation rate and the film for film thickness evaluation to deposit the film for film thickness evaluation with the deposition material at the same time as vapor deposition at the high evaporation rate. And a film thickness measuring means for measuring the evaporation rate for depositing the deposition material to a target film thickness at a low evaporation rate based on the film thickness of the film for film thickness measurement measured by the film thickness measuring means. with a low evaporation source, a low evaporation rate evaporation source is characterized in der Rukoto those formed by evaporation flow from the high evaporation rate evaporation source.

  According to the present invention, the deposition time can be shortened by depositing the deposition material to a target film thickness or less at a high evaporation rate. When the deposition is performed at a high evaporation rate, the difference in film thickness is large, but the film thickness deposited at a high evaporation rate is measured, and the difference between the measured value and the target film thickness is deposited at a low evaporation rate. Thus, it is possible to form a film with a small deviation from the target film thickness, and to form an organic EL film with a highly reproducible film thickness. As described above, it is possible to realize both shortening of the vapor deposition time and highly accurate film thickness reproducibility.

  Hereinafter, the best mode for carrying out the present invention will be described.

  In the present invention, when the organic EL film 2 is formed on the substrate 1, the organic EL film 2 is formed with a predetermined film thickness as a target value by depositing a deposition material at at least two evaporation rates. The difference in evaporation rate is preferably twice or more.

First, the vapor deposition material is vaporized from an evaporation source with a high evaporation rate, and when the target film thickness of the organic EL film 2 is D ₀ as shown in FIG. 1A, the film thickness of D ₁ is equal to or less than D _0. Vapor deposition material is deposited on the substrate 1 until. Carrying out the evaporation in the evaporation source of high evaporation rate, the deposition rate per unit time can be known in advance experimentally, by dividing the thickness D ₁ at a deposition rate per unit time, high evaporation rates The evaporation time can be determined by the evaporation source. Therefore, this time in the evaporation source of high evaporation rate, by performing vapor deposition, and is capable of forming a film 2a of a high evaporation rate to near thickness D _1.

Prospect of thickness D ₁ of the film 2a at the time of deposition at a high evaporation rate may vary depending on the value of the high evaporation rate, preferably set to be in the range 80 to 99% of the target thickness D _0. By performing the deposition at a high evaporation rate, but is capable of shortening the deposition time since deposition speed increases, the thickness D ₁ is less than 80% of the target thickness of deposited at a high evaporation rate any For example, the film thickness necessary for vapor deposition at a low evaporation rate is increased, the vapor deposition time at the low vaporization rate is increased, and the effect of shortening the vapor deposition time is impaired. Since the deviation of film thickness per unit time in the case of the deposition at a high evaporation rate is greater, the prospect of film thickness D ₁ of depositing a high evaporation rate exceeds 99% of the target thickness, the thickness of the target D there is a possibility that the thick film layer 2a in thickness than the _0.

After performing the formation of the film 2a in this way a high evaporation rate deposition, measures the thickness D ₁ of the membrane 2a. Although the deviation of the film thickness when performing the deposition at a high evaporation rate is greater, by measuring the film thickness in this manner, the film thickness at this stage assessed quantitatively to detect the accurate thickness D ₁ of the film 2a Is.

Then, based on the film thickness measurement result, the same evaporation material as above is vaporized from the evaporation source with a low evaporation rate to form the film 2b on the surface of the film 2a, and the films 2a and 2b are formed as shown in FIG. the total thickness of the film thickness is to deposit a deposition material to a film thickness D ₀ of the target. That is, even when vapor deposition is performed with an evaporation source having a low evaporation rate, the film formation rate per unit time can be experimentally known in advance, and D ₀ −D ₁ = D ₂ is vapor deposited at a low evaporation rate. since a film thickness necessary to, by dividing the thickness D ₂ at a deposition rate per unit time, it is possible to determine the time for the deposition in the evaporation source of a low evaporation rate. Therefore, this time in the evaporation source of low evaporation rate, by performing the vapor deposition, it is possible to form a film 2b having a thickness of D _2, the organic EL film 2 having a thickness of D ₀ of the target substrate 1 It can be formed on the surface. Since the film deviation of thickness per time in the case of performing the deposition at a low evaporation rate is less, it is possible to form a film 2b in the correct thickness, the thickness of the D ₀ that target organic EL film 2 accuracy The organic EL film 2 can be formed with high reproducibility.

Here, for example, the target value D ₀ of the thickness of the organic EL film 2 is 150 nm, the deposition rate when vaporize the evaporation material from the evaporation source of the high evaporation rate by deposition on the surface of the substrate 1 is 10 nm / If it is s, when the 140nm the prospect of thickness _{D 1} of depositing a high evaporation rate, the time to perform the deposition at a high evaporation rate is set to 140nm / 10 nm = 10 seconds, performing vapor deposition. Since the deposition of a high evaporation rate deviation of the film thickness is large, when measuring the thickness D ₁ was deposited for 10 seconds at a high evaporation rate, for example, a measure of 143 nm. Further, when the deposition rate is 1 nm / s when vapor deposition is performed by evaporating the deposition material from a low evaporation rate evaporation source, the film thickness D ₂ deposited at a low evaporation rate is 150 nm-143 nm = 7 nm. By performing vapor deposition for 7 seconds at a low evaporation rate, the organic EL film 2 can be formed with high accuracy to a target film thickness of D ₀ = 150 nm. Also, the time required for vapor deposition can be as short as 17 seconds in total.

  Examples of the evaporation source having a high evaporation rate or a low evaporation rate include crucibles, boats, cells, filaments, EB evaporation sources, and the like that are generally used for vapor deposition. Also, a type with a valve that varies the evaporation rate according to the opening of the valve, a surface evaporation source type in which an evaporative flow blows out from a plurality of outlets in a shower form, an evaporating flow using a carrier gas, a spray An evaporation source that is generally known to have a wide adjustment range of the evaporation rate, such as a type, can also be suitably used. When this type of evaporation source is used, the evaporation film is formed by setting the evaporation rate to two or more levels depending on the opening of the valve, the gas flow rate, and the like. Examples of the film thickness measuring means include a stylus type film thickness evaluation method and a non-contact type film thickness evaluation method. In the present invention, the film thickness of the actually formed film is changed each time. In order to perform measurement evaluation, it is possible to eliminate an error due to a change in a conversion coefficient as in the case of using a crystal resonator.

  In the present invention, a plurality of (including a plurality of groups) evaporation sources 3 and 4 are used for the same material for the organic EL film, and at least one (including the group) is an evaporation source 3 having a high evaporation rate, and the other ( The organic EL film 2 can be formed by vapor-depositing a vapor deposition material at at least two evaporation rates as described above, using the evaporation source 4 having a low evaporation rate as a group. A single evaporation source 3 having a high evaporation rate or a single evaporation source 4 having a low evaporation rate may be provided, but a plurality of evaporation sources 3 and a plurality of evaporation sources 3 or a plurality of evaporation sources may be provided as shown in FIG. By arranging the sources 4 in parallel along the substrate 1, vapor deposition can be performed uniformly on the surface of the substrate 1. In the case of FIG. 2A, first, after vapor deposition material is vaporized from the evaporation source 3 having a high evaporation rate and vapor deposition is performed at a high rate, the vapor deposition material is vaporized from the evaporation source 4 having a low evaporation rate and at a low rate. Vapor deposition is performed. Further, by forming the shape of the evaporation sources 3 and 4 in a long shape along the direction in which the evaporation sources 3 and 4 are arranged as shown in FIG. 2B, vapor deposition on the surface of the substrate 1 is performed more uniformly. It is something that can be done. 2A and 2B, the substrate 1 may be moved in a direction perpendicular to the direction in which the evaporation sources 3 and 4 are arranged.

  The ratio of the evaporation rate of the evaporation source 3 having a high evaporation rate and that of the evaporation source 4 having a low evaporation rate is not particularly limited, but the evaporation rate of the evaporation source 3 is about 2 to 100 times the evaporation rate of the evaporation source 4. It is preferable to set so as to be 4 to 30 times.

  In the embodiment of FIG. 2, the evaporation source 3 having a high evaporation rate and the evaporation source 4 having a low evaporation rate are independently formed. However, the evaporation flow from the evaporation source 3 having a high evaporation rate is an evaporation having a low evaporation rate. The source 4 may be formed. FIG. 3A shows an example of the embodiment. The heating bypass 10 is connected to the evaporation source 3 having a high evaporation rate, and the evaporation source 4 having a low evaporation rate is formed at the tip of the heating bypass 10. It is like that. A shutter 11 is provided at the opening of the evaporation source 3 having a high evaporation rate, and a valve 12 is provided at the heating bypass 10. In this case, when the vapor deposition material vaporized by the evaporation source 3 is blown directly from the evaporation source 3, since the release amount is large, the vapor deposition material is released at a high evaporation rate and vapor deposition is performed at a high film formation rate. It is something that can be done. Further, when the vapor deposition material vaporized by the evaporation source 3 is blown from the evaporation source 4 through the heating bypass 10, the vapor deposition material is released at a low evaporation rate because the blowing amount is small, and vapor deposition can be performed at a low film formation rate It is. If necessary, vapor deposition can be performed with the evaporation source 3 having a high evaporation rate by closing the valve 12 and opening the shutter 11, and evaporating by closing the shutter 11 and opening the valve 12. Evaporation can be performed with the evaporation source 4 having a low rate.

  In the embodiment of FIG. 3B, a main pipe 14 and a sub pipe 15 are connected to the evaporation source 3, and a main valve 16 and a sub valve 17 are provided on the main pipe 14 and the sub pipe 15, respectively. A main air outlet 18 and a sub air outlet 19 are provided at the ends of the main pipe 14 and the sub pipe 15, respectively. The opening diameter of the valve 16 provided in the main pipe 14 is formed larger than the opening diameter of the valve 17 provided in the sub-pipe 15, and the evaporation material is blown out at a high evaporation rate through the main outlet 18 provided in the main pipe 14. The sub blowout port 19 provided in the sub pipe 15 becomes the evaporation source 4 from which the vapor deposition material is blown out at a low evaporation rate. In this case, if necessary, the sub valve 17 is closed and the main valve 16 is opened, so that the vapor deposition material is blown out from the main outlet 18 serving as the evaporation source 3 at a high evaporation rate, and vapor deposition is performed at a high film formation rate. Further, if necessary, the main valve 16 is closed and the sub valve 17 is opened, so that the vapor deposition material is blown out from the sub blow outlet 19 serving as the evaporation source 4 at a low evaporation rate, and the low film formation rate is achieved. It is possible to perform vapor deposition.

  The embodiment of FIG. 4A shows a so-called cluster-type vapor deposition apparatus formed by connecting a plurality of vapor deposition chambers 22a, 22b,... Radially around the delivery chamber 21, and each vapor deposition chamber 22a, Shutters 23 are respectively provided at entrances and exits of the boundary between 22b... And the delivery chamber 21. In each of the vapor deposition chambers 22a, 22b..., As shown in FIG. 4B, an evaporation source 3 having a high evaporation rate and an evaporation source 4 having a low evaporation rate are provided at positions close to each other. The evaporation sources 3 and 4 have the same shape of the evaporation flow from the evaporation sources 3 and 4 to the substrate 1 in the respective vapor deposition chambers 22a, 22b. Is preferably arranged.

  In this cluster type vapor deposition apparatus, the substrate 1 is first introduced from the delivery chamber 21 into the first vapor deposition chamber 22a to form the organic EL film 2, and after this film formation is completed, the first vapor deposition chamber 22a The substrate 1 is taken out into the delivery chamber 21, and then the substrate 1 is introduced from the delivery chamber 21 into the second deposition chamber 22 b to form another organic EL film 2. , 22b... Can be formed by laminating a plurality of different organic EL films 2 in this order. Therefore, for example, as shown in FIG. 5, the anode layer 2A, the hole transport layer 2B, the organic light emitting layer 2C, the electron transport layer 2D, and the cathode layer 2E are laminated on the substrate 1 as shown in FIG. In this case, an organic EL element can be manufactured with high production efficiency by introducing the substrate 1 into each of the vapor deposition chambers 22a, 22b.

  In the embodiment shown in FIG. 6, vapor deposition is performed by moving the substrate 1 in the vapor deposition chamber 24, and the evaporation source 3 having a high evaporation rate and the evaporation source 4 having a low evaporation rate are moved in the moving direction of the substrate 1. Are arranged in this order at positions along the line. Then, when the substrate 1 is moved and the substrate 1 is positioned above the evaporation source 3 having a high evaporation rate, the evaporation material vaporized from the evaporation source 3 can be deposited on the substrate 1 at a high film formation rate. Further, when the substrate 1 passes through the position of the evaporation source 3 having a high evaporation rate and is positioned above the evaporation source 4 having a low evaporation rate, the vapor deposition material vaporized from the evaporation source 4 has a low film formation rate. Can be deposited on the substrate 1. In this case, the substrate 1 is moved so that the vapor deposition can be performed at a low evaporation rate after the vapor deposition at a high evaporation rate.

  FIG. 7 shows another embodiment of the present invention. When depositing a deposition material on the substrate 1 to form a film, the deposition is performed while measuring the thickness, and according to the measured value of the thickness. The evaporation rate and deposition time are feedback controlled. In the illustrated embodiment, the evaporation sources 3 and 4 have the same configuration as in FIG. The film thickness meter 25 for measuring the film thickness of the film deposited on the substrate 1 is connected to a control device 26 equipped with a CPU or the like, and the film thickness data measured by the film thickness meter 25 is the control device. 26, the opening / closing amount and the opening / closing amount of the main valve 16 and the sub valve 17 are controlled based on the film thickness data.

In this apparatus, deposition is performed while moving the substrate 1 from above the main outlet 18 serving as the evaporation source 3 having a high evaporation rate to above the sub outlet 19 serving as the evaporation source 4 having a low evaporation rate. . Then, the main valve 16 and the sub valve 17 are opened, and the vapor deposition material is blown out from the main blowout port 18 serving as the evaporation source 3 at a high evaporation rate, and the vapor deposition material is blown out from the sub blowout port 19 serving as the evaporation source 4 at a low evaporation rate. First, the film 2a is formed on the lower surface of the substrate 1 by vapor deposition at a high evaporation rate from the front end to the rear end in the moving direction. Thickness D ₁ of the film 2a to be deposited on the surface of the substrate 1 is measured by the film thickness measurement gauge 25, depending on the thickness D ₂ obtained from the measurement results of the thickness D _1, from the control unit 26 The opening / closing amount of the sub-valve 17 is adjusted by feedback control, and the film 2b is formed by vapor deposition at a low evaporation rate from the front end portion to the rear end portion in the moving direction of the substrate 1 as the substrate 1 moves. Thus, by measuring the film thickness and performing feedback control while performing vapor deposition, the organic EL film 2 with high film thickness accuracy can be formed. Here, the location where the film thickness meter 25 measures the film thickness of the film 2a deposited at a high evaporation rate is set between the region where the film is deposited at a high evaporation rate and the region where the film is deposited at a low evaporation rate. is there.

  As the film thickness meter 25, it is preferable to use a non-contact type in view of non-destructive evaluation and short evaluation time, and an optical film thickness meter is particularly preferable. In particular, the film thickness measurement using a commonly used crystal resonator is a conversion value based on a calibration curve prepared in advance, whereas the optical film thickness meter directly measures the film thickness, so the measurement accuracy is low. It is expensive. Examples of the optical film thickness meter include a so-called ellipsometer, a reflective interference film thickness meter, a film thickness meter by transmission spectrum evaluation, an X-ray interference film thickness evaluation device, a transmission / reflection interference film thickness meter, and the like. be able to. Among these, it is preferable to use an ellipsometer or a reflective interference type film thickness meter because the film thickness can be measured in the vapor deposition chamber during film formation, and electromagnetic waves (visible light, X-rays, etc.) are used for the thin film. ) And the reflected light and transmitted light are analyzed, so that each film can be measured independently not only for a single layer film but also for a laminated film in which a plurality of films are laminated. is there.

  The measurement evaluation of the film thickness may be performed by separately providing a position for measuring the film thickness in addition to being performed at the position where the vapor deposition is performed. Moreover, you may combine with other film thickness measuring methods, such as the film thickness-weight conversion method by a generally used crystal oscillator. In this case, the quartz crystal resonator can evaluate the evaporation rate only at a timing that is necessary, not always, and can set the vapor deposition time for high-rate evaporation based on the result. This eliminates the need to constantly monitor the high-rate evaporation flow, thereby extending the life of the crystal unit. Also, the average evaporation rate can be used as data for determining the approximate film thickness. Since it can be used while being updated, it is possible to form a film by high-rate vapor deposition up to a place that is considerably close to a predetermined film thickness.

  The measurement and evaluation of the film thickness may be performed collectively after forming several layers of the organic EL film 2 as shown in FIG. 5, or may be performed every time one layer is formed. In order to perform the thickness control feedback to each film more accurately, it is more preferable to perform it for each film formation. In addition, in the case of measuring and evaluating all together, the number of stacked layers of the film at the location where the measurement is evaluated is preferably 4 or less in both cases of measurement and evaluation. If the number of layers is larger than this, problems such as difficulty in separating the film thickness error of each layer, an error in film thickness analysis, an increase in time required for the film thickness analysis, and the like are not preferable.

  The part where the film thickness is measured and evaluated may be a part related to light emission by forming the organic EL film 2 of the substrate 1, but in order to minimize damage to the organic EL film 2, the organic EL film of the substrate 1 It is preferable to measure and evaluate the film thickness at a location different from the location where 2 is formed. FIG. 8 (a) shows an example. When the organic EL film 2 is formed on the substrate 1 by vapor deposition as described above, the organic EL film 2 is formed at the end of the substrate 1 at the same time. Vapor deposition is also performed at another position to form a film 28 for film thickness evaluation. The film thickness measurement film 28 is used to measure the film thickness as described above.

  Here, in the case where a plurality of organic EL films 2 are stacked on the substrate 1 using a plurality of materials having different compositions as shown in FIG. 8B, each of the organic EL films 2A, 2B,. Therefore, it is preferable to form the films 28A, 28B,. That is, when vapor deposition is performed using a material for forming the organic EL film 2A, a film 28A for film thickness evaluation is simultaneously vapor deposited with this material, and the film thickness of the film 28A is measured, thereby achieving high reproducibility. The organic EL film 2A can be formed with a film thickness, and when vapor deposition is performed using a material for forming the organic EL film 2B, a film 28B for film thickness evaluation is simultaneously deposited with this material. Then, by measuring the film thickness of the film 28B, the organic EL film 2B can be formed with a film thickness with high reproducibility. Similarly, the organic EL film 2C can be formed with a high reproducibility by measuring the film thickness of the film 28C for film thickness evaluation, and the reproducibility can be obtained by measuring the film thickness of the film 28D for film thickness evaluation. The organic EL film 2D can be formed with a high film thickness. When the organic EL films 2A, 2B,... Having different compositions are vapor-deposited, the respective vapor deposition materials are laminated at the same location to form a film thickness evaluation film 28, and this multilayer film thickness evaluation film Although it is possible to measure the film of each of the 28 layers by the optical film thickness evaluation method, each of the organic EL films 2A, 2B,... As described above from the viewpoint of improving the accuracy of measurement evaluation and shortening the evaluation time. .. Are preferably formed at different locations, and the film thicknesses of the film thickness evaluation films 28A, 28B... Are preferably measured and evaluated.

  The film 28 for film thickness evaluation is formed on the substrate 1 on which the organic EL film 2 is formed as described above, and a film thickness evaluation substrate is provided separately from the substrate 1 and is formed on the surface of the film thickness evaluation substrate. You may make it form the film | membrane 28 of film thickness evaluation. In this case, it is possible to use an opaque film thickness evaluation board, use a film thickness evaluation board with an appropriate refractive index, or more accurately match the positional relationship between the film thickness measurement device and the film thickness evaluation board. Therefore, it is possible to improve the accuracy of film thickness measurement evaluation. Also at this time, the formation position of the film 28 for film thickness evaluation, the number of stacked layers, and the like are appropriately set within the range based on the above-described conditions. Further, the thickness of the film 28 for film thickness evaluation formed on the film thickness evaluation substrate is not necessarily the same as the film thickness of the organic EL film 2 formed on the substrate 1 on which the organic EL film 2 is formed. . For example, when the film thickness evaluation substrate is arranged at a position farther from the vapor deposition source than the substrate 1 on which the organic EL film 2 is formed, the thickness of the film 2 for film thickness evaluation formed on the film thickness evaluation substrate is: The thickness of the organic EL film 2 formed on the substrate 1 is smaller than the thickness of the organic EL film 2 formed on the substrate 1, but the thickness of the organic EL film 2 formed on the substrate 1 can be detected by using a conversion factor obtained in advance. is there.

  In the case where a plurality of organic EL films 2 are laminated with materials having different compositions as described above, it is preferable to individually form film thickness evaluation films 28 corresponding to each organic EL film 2. In the case where a plurality of organic EL films 2 are stacked with the same composition material, the film 28 for film thickness evaluation may be formed by stacking at the same location. This is because in the case of the same composition, the amount of film formation can be quantified by measuring the film thickness of the film 28 for film thickness evaluation as an increase in film thickness. In addition, since the area for forming the film 28 for film thickness evaluation is reduced, it is not necessary to increase the unnecessary area for forming the film 28 for film thickness evaluation on the substrate 1, and in particular the film thickness evaluation board. When this is used, it is possible to use a substrate having a small area as the film thickness evaluation substrate.

  Measurement and evaluation of the film thickness is performed after the deposition at the high rate is completed, and the subsequent deposition conditions at the low rate are determined according to the value, but are performed again after the deposition at the low rate. You may do it. In this way, the film thickness is measured and evaluated after being deposited at a low rate, and the film thickness is adjusted by further performing deposition at a low rate as necessary, or other organic EL films to be subsequently formed are deposited. By appropriately changing the film thickness of the film 2, it can be utilized as important data for adjusting the characteristics of the organic EL element as a whole.

  In addition, the method for producing an organic EL element of the present invention can be utilized without any problem for an organic EL element having a structure in which a plurality of light emitting layers are laminated via an equipotential surface or a charge generation layer. This type of organic EL element is known to be sensitive to the characteristics of the film thickness and refractive index of the film constituting the organic EL element, and it is strongly desired to reproduce a more accurate film thickness. Is. Further, in the organic EL element having this structure, a plurality of films having the same composition are used. Therefore, in the film 28 for film thickness evaluation, the film having the same composition is formed at the same location, and the film thickness is increased. A method of quantifying the amount of film formation can be used more suitably.

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

  In addition, Alq3 (tris (8-hydroxyquinolinate) aluminum) is used as the vapor deposition material, and “Filmtek 3000” manufactured by SCI is used as the optical interference type film thickness measurement meter. Determined. The final target film thickness of the organic EL film 2 formed on the substrate 1 is 150 nm.

Example 1
As shown in FIG. 9, a first crucible 31 and a second crucible 32 filled with a vapor deposition material are placed close to each other in the bottom of the vapor deposition chamber 30, and a shutter 33 that opens and closes the opening on the upper surface of each crucible 31, 32. 34, and an optical interference type film thickness meter 35 was provided above the vapor deposition chamber 30. A shutter 36 is provided in the upper part of the vapor deposition chamber 30, and the substrate 1 is disposed on the upper side of the shutter 36. Further, the evaporation rate from the first crucible 31 is set so that the film forming rate is 10 nm / s, the first crucible 31 is used as the evaporation source 3 having a high evaporation rate, and the evaporation rate from the second crucible 32 is set to be the evaporation rate. The second crucible 32 was used as the evaporation source 4 having a low evaporation rate by setting the film forming rate to be 0.5 nm / s.

  Then, with the shutter 36 under the substrate 1 opened, the shutter 33 of the first crucible 31 was opened, and the evaporation material evaporating from the first crucible 31 was deposited on the substrate 1 with a film thickness of 140 nm. A film for film thickness evaluation is vapor-deposited at the end of the substrate 1 at the same time. After the vapor deposition by the first crucible 31 is finished, the film thickness for the film thickness evaluation is changed to an optical interference film. It was 143 nm when measured with the thickness meter 35 and evaluated. Next, the shutter 33 was closed and the shutter 34 was opened, and the vapor deposition material evaporating from the second crucible 32 was deposited on the substrate 1 with a film thickness aimed at 7 nm. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated.

  When the same operation was performed 30 times for 30 substrates 1, the minimum value of the organic EL film 2 formed on each substrate 1 was in the range of 149.3 nm and the maximum value was in the range of 150.4 nm. It was. The time required for film formation was 33 seconds on average.

(Example 2)
As shown in FIG. 10, the main pipe 14 and the sub pipe 15 are connected to the evaporation source 3, and the main outlet 18 and the sub outlet 19 at the tips of the pipes 14 and 15 are connected to the bottom of the vapor deposition chamber 30. Further, by adjusting the opening amounts of the main valve 16 and the sub-valve 17 provided in the main pipe 14 and the sub-pipe 15, the evaporation rate from the main blowing port 18 is set so that the film forming rate becomes 8 nm / s, and this main blowing is performed. The mouth 18 is used as the evaporation source 3 having a high evaporation rate, the evaporation rate from the sub blowout port 19 is set so that the film forming rate is 1 nm / s, and the sub blowout port 19 is connected to the evaporation source 4 having a low evaporation rate. did.

  Then, the substrate 1 is transported from above the main air outlet 18 to the sub air outlet 19. First, the substrate 1 is transported onto the main air outlet 18, the main valve 16 is opened, and the main air outlet 18 is opened. The evaporation material to be evaporated was deposited on the substrate 1 with a film thickness of 144 nm. After the vapor deposition by the main outlet 18 was finished, the film thickness was measured by an optical interference type film thickness meter 35 provided in the upper part of the vapor deposition chamber 30, and was 147 nm. Next, the main valve 16 was closed, the sub valve 17 was opened, and a vapor deposition material evaporating from the sub blowout port 19 was deposited on the substrate 1 with a film thickness aimed at 3 nm. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated.

  When the same operation was performed 30 times for 30 substrates 1, the minimum value of the organic EL film 2 formed on each substrate 1 was in the range of 149.7 nm and the maximum value was in the range of 150.9 nm. It was. The time required for film formation was 25 seconds on average.

(Example 3)
As shown in FIG. 11, in the apparatus of FIG. 9, a film thickness evaluation substrate 38 for forming a film for film thickness evaluation is provided in the vicinity of the substrate 1. Others are the same as the apparatus of FIG. The ratio of the film thickness to be formed on the film thickness evaluation substrate 38 and the film thickness to be formed on the substrate 1 was previously tested and confirmed to be 1: 1.3.

  In the same manner as in Example 1, a vapor deposition material evaporating from the first crucible 31 was vapor deposited on the substrate 1 with a film thickness of 140 nm. After the completion of the vapor deposition, the film thickness of the film formed on the film thickness evaluation substrate 38 was measured by the optical interference film thickness meter 35 and evaluated to be 108 nm, which was 140.4 nm in terms of conversion. Next, in the same manner as in Example 1, a vapor deposition material evaporating from the second crucible 32 was vapor deposited on the substrate 1 with a film thickness aiming at 9.6 nm. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated. Moreover, when the film thickness of the film | membrane on the film thickness evaluation board | substrate 38 after performing this 2nd vapor deposition was measured and evaluated with the optical interference type film thickness meter 35, it was 115.5 nm.

  Next, in the same manner as described above, the deposition material evaporating from the first crucible 31 is deposited on the substrate 1 with a film thickness of 140 nm, and after the deposition, It was 224.5 nm when the film thickness of the film | membrane formed in 38 was measured and evaluated with the optical interference type film thickness meter 35. When converted to 109 nm, which is the difference from 115.5 nm, it is 141.7 nm. Next, in the same manner as described above, a vapor deposition material evaporating from the second crucible 32 was vapor deposited on the substrate 1 with a film thickness aiming at 8.3 nm. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated.

  Hereinafter, when the same operation was repeated for 28 substrates 1, the minimum value of the film thickness of the organic EL film 2 formed on each substrate 1 was 149.0 nm, and the maximum value was in the range of 151.2 nm. Met. The time required for film formation was 33 seconds on average.

(Comparative Example 1)
Using the same apparatus as in Example 1, the evaporation rate from the first crucible 31 was set so that the film formation rate would be 10 nm / s, and only the first crucible 31 was aimed at the substrate 1 with a film thickness of 150 nm. Evaporated. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated.

  When the same operation was performed 30 times for 30 substrates 1, the time required for film formation was as short as 15 seconds on average, but the film thickness of the organic EL film 2 formed on each substrate 1 was The minimum value was 143 nm and the maximum value was 159 nm.

(Comparative Example 2)
Using the same apparatus as in Example 2, the evaporation rate from the main air outlet 18 is set so that the film forming rate is 8 nm / s, and the substrate 1 is placed on the main air outlet 18 using only the main air outlet 18. The film was transported and deposited on the substrate 1 for a film thickness of 150 nm. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated.

  When the same operation was performed 30 times for 30 substrates 1, the time required for film formation was as short as 19 seconds on average, but the film thickness of the organic EL film 2 formed on each substrate 1 was The minimum value was 142.7 nm and the maximum value was 157.9 nm.

(Comparative Example 3)
Using the same apparatus as in Example 2, the evaporation rate from the sub-blowing port 19 is set so that the film forming rate is 1 nm / s, and the substrate 1 is placed on the sub-blowing port 19 using only this sub-blowing port 19. The film was transported and deposited on the substrate 1 for a film thickness of 150 nm. The substrate 1 thus formed was taken out from the vapor deposition chamber 30, and the film thickness of the organic EL film 2 formed on the substrate 1 was measured with a stylus type film thickness meter and evaluated.

  When the same operation was performed 30 times on the 30 substrates 1, the minimum value of the organic EL film 2 formed on each substrate 1 was in the range of 149.0 nm and the maximum value was in the range of 151.2 nm. However, the time required for film formation was as long as 150 seconds on average.

In this invention, the method of forming an organic EL film | membrane by vapor deposition is shown, (a) (b) is each schematic. An example of embodiment of this invention is shown, (a) (b) is a schematic perspective view, respectively. 1 shows an example of an embodiment of the present invention, and (a) and (b) are schematic views. An example of embodiment of this invention is shown, (a) is a schematic cross-sectional view, (b) is a schematic longitudinal cross-sectional view of a vapor deposition chamber. It is the schematic which shows an example of the laminated constitution of an organic EL element. BRIEF DESCRIPTION OF THE DRAWINGS An example of embodiment of this invention is shown, (a) is a schematic cross-sectional view, (b) is a schematic longitudinal cross-sectional view. It is the schematic which shows an example of embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS An example of embodiment of this invention is shown, (a) is a schematic plan view of a board | substrate, (b) is a schematic longitudinal cross-sectional view of an organic EL element. It is a schematic longitudinal cross-sectional view which shows an example of embodiment of this invention. It is a schematic longitudinal cross-sectional view which shows an example of embodiment of this invention. It is a schematic longitudinal cross-sectional view which shows an example of embodiment of this invention.

Explanation of symbols

1 Substrate 2 Organic EL film 3 Evaporation source 4 Evaporation source

Claims (2)

In manufacturing an organic EL light-emitting device by depositing and depositing a material for an organic EL film, an evaporation source having a high evaporation rate and an evaporation source having a low evaporation rate are used as evaporation sources made of the same evaporation material. An evaporation source with a low evaporation rate is formed by an evaporation flow from an evaporation source with a high evaporation rate, and vapor deposition is performed from an evaporation source with a high evaporation rate to a target film thickness or less at a high evaporation rate. At the same time, a film for film thickness evaluation is vapor-deposited with the vapor deposition material simultaneously with the vapor deposition at the high evaporation rate, and the film thickness for the film thickness evaluation is measured. A method of manufacturing an organic EL element, comprising forming a film by evaporating an evaporation material from a low evaporation rate to a target film thickness at a low evaporation rate based on a thickness measurement result. An apparatus for manufacturing an organic EL light-emitting device by depositing a material of an organic EL film to form a film, and depositing a deposition material to a target film thickness or less at a high evaporation rate and at the high evaporation rate. An evaporation source having a high evaporation rate for depositing a film for film thickness evaluation at the same time as the deposition with the deposition material, a film thickness measuring means for measuring the film thickness of the film for film thickness evaluation, and a film thickness measuring means in based on the thickness of said measured film thickness evaluation of the film, to deposit to a thickness of a target deposition material at a low evaporation rate, and a evaporation source low evaporation rate, the evaporation rate low evaporation source apparatus for producing an organic EL element characterized in der Rukoto those formed by evaporation flow from the high evaporation rate evaporation source.

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