JP2007273243A - Manufacturing method of organic el device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing technique capable of accurately adjusting film thickness of an adjustment layer in an organic EL device. <P>SOLUTION: This manufacturing method of an organic EL device 1 includes: a process (a) for forming an organic layer 12 including a luminescent layer; and a process (b) for forming an adjustment layer for adjusting optical film thickness of a plurality of layers including the luminescent layer. The process (b) includes processes of: measuring the film thickness of the adjustment layer during formation of the adjustment layer, and adjusting the optical film thickness of the adjustment layer based on the measurement result of the film thickness of the adjustment layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for manufacturing an organic EL device.

  An organic EL (electroluminescence) device includes an organic layer including a light emitting layer.

  Some of these organic EL devices are provided with a sealing layer for sealing the organic layer in order to protect the organic layer from moisture in the atmosphere (see Patent Documents 1 and 2).

JP-A-60-202682 JP-A-4-212284

  By the way, in the organic EL device, when the light generated in the light emitting layer is emitted to the light extraction side, the light emitted from the light extraction side is reflected by the electrode layer on the opposite side and then emitted. Due to the interference with light, the overall intensity of the emitted light including both light changes according to the film thickness of the light emitting layer or the like. Therefore, for the purpose of increasing the intensity of the emitted light, it may be required to set the film thickness (more specifically, the optical film thickness) contributing to the interference action to a predetermined value.

  The sealing layer in the organic EL device has a function of sealing the light emitting layer and the like so that the light emitting layer and the like do not touch the atmosphere as described above. It preferably has a function of adjusting the film thickness (optical film thickness) of the contributing layer. That is, it is preferable that the sealing layer also serves as an “adjustment layer” for adjusting the optical film thickness.

  In this case, it is desirable to control the film thickness of the sealing layer (adjustment layer) with high accuracy. However, since the film thickness of the sealing layer is a relatively large value, even if the error in the film thickness of the sealing layer is suppressed to, for example, several percent, the absolute value of the error becomes relatively large. However, there is a problem that it may not be possible to obtain the accuracy.

  Accordingly, an object of the present invention is to provide a manufacturing technique capable of adjusting the film thickness of an adjustment layer in an organic EL device with high accuracy.

  In order to solve the above-mentioned problems, the invention of claim 1 is a method for manufacturing an organic EL device, wherein a) a step of forming an organic layer including a light emitting layer, and b) an optical of a plurality of layers including the light emitting layer. A step of forming an adjustment layer for adjusting the film thickness, wherein the step b) includes b-1) a step of measuring the film thickness of the adjustment layer during the formation of the adjustment layer, and b-2) the above And a step of adjusting the optical film thickness of the adjustment layer based on the measurement result of the film thickness of the adjustment layer.

  According to a second aspect of the present invention, in the method of manufacturing an organic EL device according to the first aspect of the invention, the adjustment layer includes a first adjustment layer and a second adjustment layer, and the step b-1) includes And a step of measuring the thickness of the first adjustment layer during the formation of the first adjustment layer, and the step b-2) is based on the measurement result of the thickness of the first adjustment layer, The method includes the step of additionally forming the second adjustment layer.

  According to a third aspect of the invention, in the method of manufacturing an organic EL device according to the second aspect of the invention, the first adjustment layer and the second adjustment layer are made of different materials.

  According to a fourth aspect of the invention, in the method for manufacturing an organic EL device according to the second aspect of the invention, the first adjustment layer and the second adjustment layer are made of the same material.

  According to a fifth aspect of the invention, in the method for manufacturing an organic EL device according to the first aspect of the invention, the step b-2) includes a step of reducing the thickness of the adjustment layer.

  A sixth aspect of the present invention is the method of manufacturing an organic EL device according to the first aspect of the invention, wherein the step b-2) is a step of adjusting the optical film thickness of the adjustment layer by irradiating the adjustment layer with ultraviolet rays. It is characterized by having.

  A seventh aspect of the present invention is the method of manufacturing an organic EL device according to any one of the first to sixth aspects, wherein in the step b-1), the thickness of the dummy pattern related to the adjustment layer is measured. Thus, the film thickness of the adjustment layer is measured.

  The invention of claim 8 is the method of manufacturing an organic EL device according to any one of claims 1 to 7, wherein in the step b-1), the intensity of reflected light or transmitted light of the adjustment layer is adjusted. The film thickness of the adjustment layer is measured by measuring a change with time during the formation of the adjustment layer.

  According to a ninth aspect of the present invention, in the method for manufacturing an organic EL device according to the eighth aspect of the present invention, in the step b-1), at least a period immediately before the film formation is stopped in the film formation period of the adjustment layer. A change in the intensity of the reflected or transmitted light is measured over a period including a first time corresponding to a last maximum or a last minimum in the reflected light or transmitted light intensity change curve, The film thickness of the adjustment layer is calculated using an actual measurement time from a first time to a scheduled film formation stop time and a theoretical value of the film thickness at the first time.

  According to a tenth aspect of the present invention, in the method of manufacturing an organic EL device according to the ninth aspect of the present invention, in the step b-1), at least a film formation stop in the change curve is made during the film formation period of the adjustment layer. Changes in the intensity of the reflected light or transmitted light are measured over the period of measuring the last two extreme values, and the actual measurement time from the first time to the scheduled film formation stop time and the film thickness at the first time. The film thickness of the adjustment layer is calculated using the theoretical value and the measurement time interval between the two extreme values.

  According to an eleventh aspect of the present invention, in the method of manufacturing an organic EL device according to any one of the first to tenth aspects, the step b-1) includes the step of forming the adjustment layer during the formation of the adjustment layer. Measuring the thickness at a plurality of positions, and the step b-2) corresponds to each of the plurality of positions based on the measurement result of the thickness of the adjustment layer at each of the plurality of positions. It has the process of adjusting the film thickness of the said adjustment layer for every area | region.

  According to the invention described in claims 1 to 11, the film thickness of the adjustment layer is measured during the formation of the adjustment layer, and the film thickness of the adjustment layer is adjusted based on the measurement result of the film thickness of the adjustment layer. Therefore, the film thickness of the adjustment layer in the organic EL device can be adjusted with high accuracy.

  In particular, according to the invention described in claim 9, it is possible to accurately measure the film thickness.

  In particular, according to the invention described in claim 10, even when the film formation rate changes during film formation, it is possible to accurately measure the film thickness while minimizing the influence thereof.

  In particular, according to the invention described in claim 11, the in-plane distribution can be equalized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
<Configuration of organic EL device>
FIG. 1 is a cross-sectional view of an organic EL device 1 (1A) according to this embodiment. As shown in FIG. 1, the organic EL device 1 </ b> A includes a first electrode layer (here, anode) 11, an organic layer 12, a second electrode layer (cathode) 13, a Cap layer 14, and a first adjustment layer 15. And the second adjustment layer 16 are stacked in this order. Although not shown here, below the first electrode layer 11, there are a circuit layer having a drive circuit (TFT drive circuit, etc.), a substrate composed of a glass substrate, and the like. Yes. This organic EL device 1A employs a top emission type structure in which the light emitted from the organic layer 12 is extracted to the outside through the upper layer 13, 14, 15, 16. However, the present invention is not limited to this, and a bottom emission type structure may be adopted.

  In the organic EL device 1A, in order to emit color light, three types of light emitting / outputting units having the same layer structure (see FIG. 1) have three primary color components (red (R)) at different positions (adjacent positions) on the substrate plane. , Green (G), and blue (B)). In the organic EL device 1A, the combination of these three types of light output units is two-dimensionally arranged on the substrate plane, and the organic EL device 1A functions as a display (organic EL display).

  The organic layer 12 includes a light emitting layer using an organic material as a light emitter. In the organic layer 12, a material suitable for emitting light of each wavelength of red, green, and blue is used according to the planar position.

  The organic layer 12 can employ either a single layer structure or a multilayer structure laminated according to function.

  For example, in a single layer structure in which the organic layer 12 is composed of only a light emitting layer, the light emitting layer is made of a material having both hole transport characteristics and electron transport characteristics, and a method of doping the light emitting material into the material, For example, a method using a material in which a charge transport property is imparted to the light emitting material itself can be employed. Such a single layer structure can simplify the element formation process, and thus can improve the yield and provide the low-cost organic EL device 1A.

  Moreover, when adopting a multilayer structure as the structure of the organic layer 12, for example, in addition to the light emitting layer, among the hole transport layer, the hole injection layer, the hole blocking layer, the electron transport layer, the electron injection layer, and the electron blocking layer It is possible to configure the organic layer 12 by selecting one or more. In addition, although an inorganic material may be used about a positive hole injection layer and an electron injection layer, even in that case, a positive hole injection layer and an electron injection layer are called an organic layer.

  The first electrode layer 11 constitutes a lower electrode of the organic layer 12. The first electrode layer 11 reflects at least part of the light emitted from the organic layer 12 to the organic layer 12 side, and may be formed using any of transparent, translucent, and opaque electrode materials. Good. However, in order to increase the reflectance of light, the first electrode layer 11 is preferably formed as a translucent electrode or an opaque photoelectrode. The first electrode layer 11 is preferably formed, for example, as an aluminum (Al) reflective electrode.

  The second electrode layer 13 is formed of a conductive material that transmits light in order to extract light from the upper surface side of the organic layer 12. In order to increase the light transmittance, the second electrode layer 13 is preferably a translucent electrode or a transparent electrode. The second electrode layer 13 is preferably formed using a light-transmitting conductive material such as an indium tin oxide film (ITO) or a tin oxide film (IZO).

  The opaque electrode is formed of a material having optical characteristics that shield most of visible light and high electrical conductivity. In addition, the transparent electrode is formed of a material having optical characteristics that allow most visible light to pass therethrough and relatively large electrical conductivity. Moreover, a semi-transparent electrode has an intermediate characteristic between a transparent electrode and an opaque electrode.

  The Cap layer 14 is for adjusting the light transmission characteristics for each of the color components R, G, and B. The adjustment layer 15 and the like described below adjust the optical film thickness independent of the color component, whereas the Cap layer 14 adjusts the optical film thickness for each of the color components R, G, and B, It plays a role of absorbing the difference in light transmission characteristics for each of the components R, G, and B.

  The first adjustment layer 15 is made of a light transmissive material. The first adjustment layer 15 has a function of adjusting the optical film thickness (n × d; n is a refractive index and d is a film thickness) of a plurality of layers including the light emitting layer of the organic EL device 1A. Moreover, the 1st adjustment layer 15 is formed so that these surfaces may be covered from the organic layer 12, the 2nd electrode layer 13, and the Cap layer 14, and it has the sealing capability with respect to a water | moisture content, gas, etc. . That is, the first adjustment layer 15 also has a function as a protective layer that protects the organic layer 12 and the like.

  The second adjustment layer 16 is made of a light transmissive material and is laminated on the first adjustment layer 15. Similarly to the first adjustment layer 15, the second adjustment layer 16 also has a function of adjusting the optical film thickness of a plurality of layers including the light emitting layer of the organic EL device 1 </ b> A. The first adjustment layer 15 plays a role of roughly adjusting the optical film thickness, whereas the second adjustment layer 16 plays a role of performing fine adjustment of the optical film thickness. Note that the second adjustment layer 16 may or may not have a function as a protective layer (sealing layer).

  Suitable materials for the adjustment layers 15 and 16 are materials having optical transparency, for example, transparent inorganic materials such as silicon nitride (SiNx), titanium oxide, and zinc sulfide, or transparent organic materials such as styrylarylene and polysilane. Etc. In the first embodiment, it is assumed that the first adjustment layer 15 and the second adjustment layer 16 are made of different materials. For example, the first adjustment layer 15 is made of silicon nitride, and the second adjustment layer 16 is made of titanium oxide.

  Thus, the 1st adjustment layer 15 and the 2nd adjustment layer 16 function as an adjustment layer which adjusts the optical film thickness of the several layer containing a light emitting layer. In other words, the adjustment layer that adjusts the optical film thickness of the plurality of layers including the light emitting layer includes two sub adjustment layers (the first sub adjustment layer 15 and the second sub adjustment layer 16).

<Outline of adjustment layer deposition process>
Here, for the purpose of increasing the intensity of the emitted light in the organic EL device, it is required to set the film thickness (more specifically, the optical film thickness) contributing to the interference action to a predetermined value. To do.

  For this reason, the first adjustment layer 15 has a function of sealing the light emitting layer or the like so that the light emitting layer or the like does not come into contact with the atmosphere. It also has a function of adjusting the thickness (optical film thickness).

  Here, the film thickness of the first adjustment layer 15 has a relatively large value in order to fulfill the function as the protective layer described above, and specifically, the wavelength of visible light (several hundred nm (nanometer)). ) (For example, 1 μm to 3 μm (micrometer)) (about several wavelengths of visible light).

  When the film formation process of the first adjustment layer 15 is controlled by an open loop, an error of several percent can occur even if the film formation conditions are sufficiently adjusted. Since the film thickness of the first adjustment layer 15 has a relatively large value, even if the error in the film thickness is suppressed to several percent (for example, 5%), the absolute value of the error is a relatively large value. (For example, 50 nm to 150 nm, (about a fraction of the wavelength)), and sufficient accuracy may not be obtained for adjusting the optical film thickness.

  Therefore, in order to solve such a problem, in this embodiment, the film thickness of the first adjustment layer 15 is measured during the film forming process, and the second adjustment layer 16 is further added according to the measurement result. Form.

  Next, the film forming process will be described in detail.

  FIG. 2 is a schematic perspective view showing a vapor deposition apparatus (film formation apparatus) 100A used for film formation processing of the first adjustment layer 15 and the like. FIG. 2 illustrates a case where a plurality of organic EL devices 1 (1A) are manufactured on one substrate 10. However, the present invention is not limited to this, and the single organic EL device 1 may be manufactured on one substrate 10.

  Here, it is assumed that the above-described layers 11 to 14 are formed in advance, and the operation and the like of forming the first adjustment layer 15 that is the next layer using the vapor deposition apparatus 100A will be described.

  As shown in FIG. 2, the vapor deposition apparatus 100A includes a vapor deposition source 102 for film vapor deposition in a chamber. A substrate to be processed (substrate to be processed) 10 is disposed above the vapor deposition source 102. The vapor deposition apparatus 100A can make the inside of the chamber in a vacuum state and can perform vacuum vapor deposition.

  During the vapor deposition process, a vapor deposition is supplied from the vapor deposition source 102 and deposited on the lower surface side of the substrate 10, and a vapor deposition film (here, the first adjustment layer 15) is formed on the lower surface side of the substrate. In FIG. 1, it has been described that the layers are formed sequentially from the bottom to the top. However, in FIG. 2, the layers are formed from the top to the bottom. Therefore, in FIG. 2, the first adjustment layer 15 is formed further below the layers 11 to 14 formed in advance on the lower side of the substrate.

  In addition, the vapor deposition apparatus 100 </ b> A includes a film thickness measurement unit 30 and a control unit 40.

  The film thickness measurement unit 30 includes a light projecting unit 31 and a light receiving unit 32, and the control unit 40 includes a film formation control unit 41 and a film thickness measurement control unit 42.

  The film formation control unit 41 controls the film formation process. Specifically, the film formation control unit 41 supplies a predetermined concentration of deposited material, realizes a film formation process at a substantially constant rate, and forms the first adjustment layer 15 until a predetermined time T1 elapses. Continue the membrane treatment.

  The film thickness measuring unit 30 measures a change (time-dependent change) in the intensity of reflected light from the first adjustment layer 15 during film formation of the first adjustment layer 15. Specifically, when laser light (for example, visible light laser) is emitted from the light source in the light projecting unit 31, the emitted laser light is reflected by the first adjustment layer 15 of the organic EL device 1A. Light is received by the light receiving unit 32. The light receiving unit 32 converts the received light intensity into an electric signal and transmits it to the film thickness measurement control unit 42. The film thickness measurement control unit 42 obtains the change over time of the light reception intensity of the reflected light from the first adjustment layer 15 and, as will be described later, the film thickness (measurement value) of the first adjustment layer 15 based on the change over time. Is calculated. Then, when the film formation process of the first adjustment layer 15 over a predetermined period T1 is completed due to the arrival of the scheduled film formation stop time (theoretical value for realizing a desired film thickness) t20 (see FIG. 3 described later). The film thickness measurement control unit 42 calculates the film thickness (measured value) at the end (when the film formation is stopped).

  Thus, the film thickness measurement unit 30 and the film thickness measurement control unit 42 measure the film thickness D1 of the first adjustment layer 15 during the film formation of the first adjustment layer 15.

  Next, the film formation control unit 41 additionally forms the second adjustment layer 16 based on the measurement result of the film thickness D1 of the first adjustment layer 15. The film thickness D2 of the second adjustment layer 16 is determined based on the measurement result of the film thickness of the first adjustment layer 15. The thickness of the adjustment layer including the first adjustment layer 15 and the second adjustment layer 16 is adjusted by additionally forming the second adjustment layer 16 based on the measurement result of the film thickness of the first adjustment layer 15. Therefore, the film thickness of the adjustment layer in the organic EL device can be adjusted with high accuracy.

<Detailed operation of film thickness measurement principle and film forming process>
FIG. 3 is a diagram for explaining the principle of film thickness measurement, and shows the change over time in the intensity of reflected light from the first adjustment layer 15 during film formation.

  When the first adjustment layer 15 is formed at a substantially constant rate, the reflected light intensity of the first adjustment layer 15 is, for example, a sinusoidal curve during the formation of the first adjustment layer 15 as shown in FIG. It changes periodically like drawing. This is because light reflected at one interface of the first adjustment layer 15 (interface between the first adjustment layer 15 and air) and reflection at the other interface (interface between the first adjustment layer 15 and the Cap layer 14). This is because the intensity of the overall reflected light including both lights changes according to the film thickness of the first adjustment layer 15 due to the interference with the light to be transmitted.

  Here, if the time (period) between adjacent peaks of the change curve is Tp, the period Tp of the optical path length difference between the reflected light at one interface of the first adjustment layer 15 and the reflected light at the other interface. The amount of change in is equal to the wavelength λ. Therefore, in consideration of Snell's law and the like, the change amount Dp of the film thickness of the first adjustment layer 15 in the period Tp is equal to the wavelength λ of the laser light emitted from the light projecting unit 31 and the first adjustment layer 15. Using the refractive index n of the film quality and the incident angle θ of the laser beam (see FIG. 2), it is expressed by equation (1).

  Since the values λ, n, and θ included in the right side in Expression (1) are all known, the change amount Dp is calculated by Expression (1).

  By the way, the target value of the film thickness of the first adjustment layer 15 is the number of peaks in the reflected light intensity change curve from the film formation start time to the film formation end time (film formation stop time) and the peak immediately before the film formation end. Can be expressed in terms of the amount of film formation after the arrival time (α × Dp). The value α is a value calculated and set in advance according to the target value of the first adjustment layer 15.

  In addition, the relationship between the change amount Dp, the actual film formation rate βp, and the period Tp (measured value) is also expressed by equation (2).

  Here, over the period Tx (measured value) from the time t10 corresponding to the last peak PK (i) immediately before the film formation end time in the change curve to the film formation stop scheduled time t20, the actual growth rate is βp. Assuming that the film processing has progressed, the increase Dx in the film thickness during the period Tx is expressed by Equation (3).

  If the actual film formation rate βp and the theoretical film formation rate β are different values, the time at which the peak PK (i) immediately before the film formation end time actually reaches is different from the theoretical value. become. However, the film thickness at time t10 when the change curve actually reaches the peak PK (i) is equal to the predetermined film thickness d1 (theoretical value) corresponding to the peak PK (i).

  Thus, here, it is determined that the predetermined film thickness d1 has been reached at the peak arrival time t10, and the actual measurement time from the time t10 to the scheduled film formation stop time (which is also the film formation end time in this embodiment) t20. In Tx, it is considered that the film thickness Dx calculated using the equation (3) further increases.

  Specifically, when the film formation is completed, the actual film formation rate βp is calculated by Expression (2), and the value Dx is obtained by Expression (3). As a result, the film thickness at the end of film formation of the first adjustment layer 15 is obtained as the value (d1 + Dx). In this way, the step of measuring the thickness of the first adjustment layer 15 is performed during the formation of the first adjustment layer 15.

  Next, a step of adjusting the film thickness of the adjustment layer based on the measurement result of the film thickness of the first adjustment layer 15 is executed. Specifically, the film thickness of the adjustment layer is adjusted by performing a process of additionally forming the second adjustment layer 16 based on the measurement result of the film thickness of the first adjustment layer 15.

  Therefore, first, the film thickness measurement control unit 42 calculates a film thickness (additional film thickness) Da to be additionally generated by the following equation (4).

  However, the film thickness Da in the formula (4) is a film thickness in the case of having the same refractive index. Here, since the second adjustment layer 16 and the first adjustment layer 15 are made of different materials, as shown in the equation (5), the refractive index Nb of the second adjustment layer 16 and the first adjustment layer 15 A value Db adjusted by multiplying the ratio of the refractive index n to the film thickness Da is set as the “additional film thickness”.

  Then, the film thickness measurement control unit 42 transmits this value Db (= D2) to the film formation control unit 41, and the film formation control unit 41 performs the next film formation process of the second adjustment layer 16. Specifically, the film formation control unit 41 changes the vapor deposition and adjusts various conditions such as temperature, and then forms the second adjustment layer 16 over a predetermined time T2. The time T2 is determined by, for example, T2 = Db / β2 (where the value β2 is the film formation rate (theoretical value) of the second adjustment layer 16).

  As described above, the film thickness of the first adjustment layer 15 is measured during the film formation, and the second adjustment layer 16 is additionally formed based on the measurement result of the film thickness of the first adjustment layer 15. Since the film thickness of the adjustment layer including the first adjustment layer 15 and the second adjustment layer 16 is adjusted, the film thickness of the adjustment layer in the organic EL device can be adjusted with high accuracy.

  In particular, since the film thickness of the second adjustment layer 16 is smaller than the film thickness of the first adjustment layer 15 (for example, about 1 to several tenths of a fraction of the film thickness of the first adjustment layer), Even if a manufacturing error with the same ratio as that of the first adjustment layer 15 occurs, the absolute value of the film thickness error of the second adjustment layer 16 becomes relatively small, and the film thickness can be adjusted with high accuracy.

  In addition, the film thickness measurement unit 30 and the film thickness measurement control unit 42 measure the change (time-dependent change) in the intensity of the reflected light from the first adjustment layer 15 during the film formation of the first adjustment layer 15 and complete the film formation. The last peak arrival time t10 immediately before is obtained. Then, the film thickness of the first adjustment layer 15 is calculated on the assumption that the film formation process proceeds at a predetermined film formation rate in the period Tx from the time t10 to the end of film formation. Specifically, the film thickness of the first adjustment layer 15 at the end of the film formation is calculated using the time Tx from the time t10 to the end of the film formation and the film thickness d1 at the time t10. According to this, the required time difference due to the difference between the actual film formation rate βp and the theoretical film formation rate β in the period until the predetermined film thickness d1 (corresponding to time t10) is formed is absorbed. The film thickness of the first adjustment layer 15 can be accurately measured. Therefore, for example, even when the film formation rate is different for each lot, it is possible to perform appropriate film thickness adjustment in each lot.

  At this time, instead of using the film formation rate β (theoretical value), the first film formed in the period Tx using the actual film formation rate βp over the period Tp between adjacent peaks immediately before the film formation ends. The film thickness of the adjustment layer 15 is calculated, and the film thickness of the first adjustment layer 15 at the end of film formation is calculated. Specifically, the actual film formation rate βp calculated from the film thickness d1 at time t10, the time Tx from the time t10 to the end of film formation, and the measurement time interval Tp of the last two peaks (extreme values). Are used to calculate the film thickness at the end of film formation. Since the actual film formation rate βp immediately before film formation is used, the film formation rate changes within the film formation period of the first adjustment layer 15 in a certain lot (for example, the film formation rate gradually decreases). ), It is possible to accurately measure the film thickness while minimizing the influence of fluctuations in the film formation rate.

  In the above description, the peak (maximum value) just before the film formation is used, but the present invention is not limited to this, and a valley (also called a valley or a minimum value) may be used.

  In the above description, the time Tp between adjacent peaks is used. However, the present invention is not limited to this, and the time Tv between adjacent valleys may be used. Furthermore, twice the time between adjacent peaks and valleys may correspond to the time Tp (or Tv). In this way, two extreme values in the change curve of the intensity of the reflected light may be measured.

  In the film thickness measurement operation of the first adjustment layer 15 described above, it is not always necessary to continue the measurement operation over the entire period from the film formation start point to the film formation end point.

  For example, when the difference between the actual film formation rate βp and the theoretical film formation rate β is very small and there is no possibility of misidentifying the peak PK (i) (the peak position) For example, when the deviation corresponds to about one-fifth or less of the wavelength), a certain period of time immediately before the end of film formation including the vicinity of the scheduled arrival time for the peak PK (i) in the film formation period of the adjustment layer The measurement operation may be performed at. More specifically, the intensity of the reflected light over a certain period including a time (for example, t10) corresponding to the last maximum value (or the last minimum value) in the change curve of the reflected light intensity and a scheduled filming stop time t20. Change can be measured.

  In this case, it is particularly preferable to measure the intensity change of the reflected light over the period of measuring the two extreme values immediately before the film formation is stopped in the film formation period of the adjustment layer. Specifically, it is preferable to measure the intensity change of the reflected light over the period immediately before the film formation stop scheduled time t20 and during the period in which the last two extreme values in the intensity change curve of the reflected light are measured. According to this, even when the film formation rate gradually changes within the film formation period of the first adjustment layer 15 in a certain lot, the influence of the fluctuation can be minimized. The last two extreme values include (1) the last two maximum values, (2) the last two minimum values, or (3) a combination of the last maximum value and the last minimum value, Any of these may be adopted.

  Moreover, in the above, although both the 1st adjustment layer 15 and the 2nd adjustment layer 16 are formed using the same vapor deposition apparatus 100A, it is not limited to this, It is 2nd adjustment using another vapor deposition apparatus. Layer 16 may be generated.

  In the above description, the target value of the film thickness of the first adjustment layer 15 is set so that the optical film thickness of the adjustment layer can be adjusted by additionally forming the second adjustment layer 16. It is preferable to set a value obtained by subtracting a small amount of film thickness in advance. In other words, the period T1 is set to a relatively small value so that the first adjustment layer 15 having a film thickness smaller than a required amount for adjusting the adjustment layer by the first adjustment layer 15 alone is formed. It is preferable to make it.

  Further, in the above, as shown in FIG. 3, the film thickness is measured based on the peak position of the intensity change of the reflected light, not the absolute value of the reflected light intensity. Therefore, even if the intensity of the laser light emitted from the light projecting unit 31 is weakened due to aging, the influence of changing the absolute value of the reflected light intensity is avoided, and the film thickness is accurately set. It is possible to measure.

<2. Second Embodiment>
In the first embodiment, after measuring the film thickness of the first adjustment layer 15, the second adjustment layer 16 made of a material different from the adjustment layer 15 is provided on the first adjustment layer 15. Although the case was illustrated, it is not limited to this. For example, the first adjustment layer 15 and the second adjustment layer 16 may be made of the same material. In the second embodiment, such a modification will be described. In the following description, differences from the first embodiment will be mainly described in order to avoid duplication of explanation.

  FIG. 4 is a cross-sectional view of the organic EL device 1 (1B) according to the second embodiment. As shown in FIG. 4, the organic EL device 1 </ b> B includes a first electrode layer (here, anode) 11, an organic layer 12, a second electrode layer (cathode) 13, a Cap layer 14, and an adjustment layer 17. It has a structure laminated in this order. That is, the organic EL device 1B according to the second embodiment has one adjustment layer 17 in place of two different first adjustment layers 15 and second adjustment layers 16, and the organic EL device according to the first embodiment. Different from the device 1A. The adjustment layer 17 has the same function as the first adjustment layer 15 described above (that is, a sealing function for sealing the organic layer 12 and the like, and an adjustment function for adjusting the optical film thickness).

  In the second embodiment, the film thickness of the adjustment layer 17 is measured during the formation of the adjustment layer 17, and the film thickness of the adjustment layer 17 is adjusted based on the measurement result of the film thickness of the adjustment layer 17.

  If the adjustment layer 17 is divided into the adjustment layer 17a and the adjustment layer 17b for the sake of convenience, the same processing as in the first embodiment is performed. Specifically, the film thickness of the adjustment layer 17a is measured during the film formation of the adjustment layer 17a, and the adjustment layer 17b is additionally formed based on the measurement result of the film thickness of the adjustment layer 17a. Here, the adjustment layer 17 is formed of, for example, silicon nitride, and both the adjustment layer 17a and the adjustment layer 17b are formed of the same material (for example, silicon nitride).

  Also in the second embodiment, the measurement process as shown in FIG. 3 is performed. Specifically, during the formation of the adjustment layer 17, the change in the reflected light intensity of the adjustment layer 17 is measured in a period including the period Tp and the period Tx, and the film formation process over the initial scheduled time T1 is performed. Then, the actual film formation rate βp is calculated by the equation (2), and the value Dx is obtained by the equation (3). As a result, the film thickness of the adjustment layer 17 (17a) at the scheduled film formation stop time t20 is obtained as a value (d1 + Dx). Thus, the process of measuring the film thickness of the adjustment layer 17 (17a) is performed during the film formation of the adjustment layer 17 (17a).

  Subsequently, a step of adjusting the film thickness of the adjustment layer based on the measurement result of the film thickness of the adjustment layer 17 (17a) is performed. Specifically, the film thickness of the adjustment layer is adjusted by performing a process of additionally forming the adjustment layer 17b based on the measurement result of the film thickness of the adjustment layer 17a. Specifically, first, a film thickness (additional film thickness) Da to be additionally generated is calculated using the equation (4), and the film thickness Da is set as “additional film thickness”. Then, the film formation control unit 41 sets the time T2 for realizing the additional film thickness Da, performs the film formation process of the adjustment layer 17 (17b), and finally performs the film formation process when the time T2 has elapsed. finish. The time T2 is calculated by, for example, T2 = Da / βp.

  According to the above process, it is possible to adjust the film thickness of the adjustment layer 17 to a desired value (d1 + α × Dp) with high accuracy.

  The processing in the second embodiment is also expressed as the following processing. That is, it is determined that the film thickness of the predetermined value (α × Dp) has been formed by the film forming process after time t10, instead of immediately ending the film forming in response to the arrival of the scheduled filming stop time t20. It is also expressed as a process of ending the formation of the adjustment layer 17 at the time.

<3. Third Embodiment>
In the said 1st and 2nd embodiment, although the case where the adjustment layer was further formed after measuring the film thickness of the adjustment layer in film-forming was illustrated, it is not limited to this. In the third embodiment, the case where the film thickness of the adjustment layer being formed is measured and then the formed adjustment layer is shaved to adjust the film thickness is illustrated.

  FIG. 5 is a cross-sectional view showing an organic EL device 1C according to the third embodiment. The left side of FIG. 5 shows a state before cutting, and the right side of FIG. 5 shows a state after cutting.

  In this way, the film formation process of the adjustment layer 17 is performed at a substantially constant rate over the time T1, and the film thickness of the adjustment layer 17 is measured during the film formation process of the adjustment layer 17. The measurement technique is as described above.

  Thereafter, when the film formation process of the adjustment layer 17 over time T1 is completed, the film thickness of the formed adjustment layer 17 is calculated. Here, a value larger than the value (theoretical value) necessary for forming the final target film thickness is set as the time T1, and the adjustment layer 17 thicker than the target value is formed. Then, the target value d30 and the current film thickness value d31 are compared to calculate the surplus amount d32 (= d31−d30), and the portion of the adjustment layer 17 corresponding to the surplus amount d32 is shaved by etching or the like, and the adjustment layer 17 Is adjusted to the target value d30.

  As described above, the film thickness of the adjustment layer 17 is measured by measuring the film thickness of the adjustment layer 17 and reducing the film thickness of the adjustment layer 17 based on the measurement result of the film thickness of the adjustment layer 17. Since the thickness is adjusted, the thickness of the adjustment layer 17 in the organic EL device can be adjusted with high accuracy.

  In particular, since the etching amount is smaller than the film thickness of the adjustment layer 17, a highly accurate film thickness adjustment process can be performed.

<4. Fourth Embodiment>
The fourth embodiment is also a modification similar to the third embodiment, and exemplifies a case where the film thickness of the adjustment layer being formed is measured and then the formed adjustment layer is shaved to adjust the film thickness.

  FIG. 6 is a cross-sectional view showing an organic EL device 1D according to the fourth embodiment. The left side of FIG. 6 shows a state before cutting, and the right side of FIG. 5 shows a state after cutting.

  As shown in FIG. 6, the first adjustment layer 15 having both the sealing function and the optical film thickness adjustment function, and the second adjustment layer 16 having no sealing function and the optical film thickness adjustment function, After forming while measuring the film thickness of both layers 15 and 16, you may make it scrape the 2nd adjustment layer 16 according to a measurement result.

  Specifically, the film formation process of the first adjustment layer 15 is performed, and the film thickness d37 of the adjustment layer 15 is measured during the film formation process of the adjustment layer 15. Similarly, for the second adjustment layer 16, the film formation process for the second adjustment layer 16 is performed, and the film thickness d 38 of the second adjustment layer 16 is measured during the film formation process for the second adjustment layer 16. Then, the total film thickness d36 of the film thickness d37 of the first adjustment layer 15 and the film thickness d38 of the second adjustment layer 16 is calculated. Here, the first adjustment layer 15 and the second adjustment layer 16 are formed so that the total film thickness d36 at this point is larger than the final target film thickness d35. Thereafter, the target value d35 and the total film thickness d36 are compared to calculate a surplus amount d39 (= d36−d35), and the portion of the second adjustment layer 16 corresponding to the surplus amount d39 is shaved by etching or the like to perform the first adjustment. The total film thickness of the layer 15 and the second adjustment layer 16 is adjusted to the target value d35.

  As described above, the film thickness of the adjustment layer including the first adjustment layer 15 and the second adjustment layer 16 is measured, and the film thickness of the second adjustment layer 16 is determined based on the measurement result of the film thickness. Is reduced, the thickness of the adjustment layer including the first adjustment layer 15 and the second adjustment layer 16 is adjusted, so that the thickness of the adjustment layer in the organic EL device can be adjusted with high accuracy. It is.

<5. Fifth Embodiment>
In each of the above embodiments, the case where the film thickness of the adjustment layer is further adjusted after the film thickness of the adjustment layer being formed is measured, but the present invention is not limited thereto. In the fifth embodiment, after measuring the film thickness of the adjustment layer during film formation, the formed film is irradiated with ultraviolet rays to change the optical characteristics (specifically, the refractive index) of the material. The case where the “optical film thickness” of the adjustment layer is adjusted is exemplified.

  FIG. 7 is a cross-sectional view showing an organic EL device 1E according to the fifth embodiment. The left side of FIG. 7 shows a state before ultraviolet irradiation, and the right side of FIG. 7 shows a state after ultraviolet irradiation.

  Specifically, the film formation process of the first adjustment layer 15 is performed, and the film thickness d51 of the adjustment layer 15 is measured during the film formation process of the adjustment layer 15. Similarly, for the second adjustment layer 18, the film formation process for the second adjustment layer 18 is performed, and the film thickness d 52 of the second adjustment layer 18 is measured during the film formation process for the second adjustment layer 18. The first adjustment layer 15 is made of, for example, silicon nitride, and the second adjustment layer 18 is made of a photosensitive material such as polysilane. The total film thickness d53 of the film thickness d51 of the first adjustment layer 15 and the film thickness d52 of the second adjustment layer 18 can also be calculated.

  Then, the refractive index of the 2nd adjustment layer 18 is changed into a desired value by irradiating the 2nd adjustment layer 18 formed with photosensitive materials, such as polysilane, using the ultraviolet irradiation part 50 with an ultraviolet-ray. The desired refractive index value N after the change includes the actual film thickness values (d51, d52) of the first adjustment layer 15 and the second adjustment layer 18, the refractive index n1 of the first adjustment layer 15, and the first It is calculated based on the relational expression (6) with the target value Cd of the optical film thickness of the adjustment layer including both the adjustment layer 15 and the second adjustment layer 18.

  The target value Cd of the optical film thickness uses the target film thickness values (d55, d56) of the first adjustment layer 15 and the second adjustment layer 18 and the refractive index n2 of the second adjustment layer 18 before the ultraviolet irradiation. It can also be expressed as equation (7).

  Further, the ultraviolet irradiation amount for changing the refractive index of the second adjustment layer 18 after the ultraviolet irradiation to the desired value N is the ultraviolet irradiation amount (irradiation time) and the refractive index change of the second adjustment layer 18. Find it based on the relationship. The relationship between the amount of irradiation of ultraviolet rays (irradiation time) and the refractive index change of the second adjustment layer 18 can be obtained in advance by experiments or the like.

  Then, by actually irradiating the calculated amount of ultraviolet rays, the refractive index of the second adjustment layer 18 is changed, and the optical film thickness of the adjustment layer including the first adjustment layer 15 and the second adjustment layer 18 is changed. Can be adjusted.

  As described above, the film thickness of the adjustment layer including the first adjustment layer 15 and the second adjustment layer 18 is measured, and the adjustment layer (second adjustment layer 18) is irradiated with ultraviolet rays to adjust the adjustment layer. Since the optical film thickness of the layer is adjusted, the film thickness of the adjustment layer in the organic EL device can be adjusted with high accuracy.

  In particular, since the amount of change in the refractive index per unit time during ultraviolet irradiation is relatively small, it is possible to finely adjust the film thickness. That is, adjustment accuracy can be improved.

<6. Sixth Embodiment>
In each of the above embodiments, the in-plane distribution (variation according to the plane position) of the adjustment layer of the organic EL device is not mentioned, but in the sixth embodiment, the in-plane distribution is equalized. A technique that can be used will be described.

  FIG. 8 is a conceptual diagram showing a vapor deposition apparatus (film formation apparatus) 100B according to the sixth embodiment.

  As shown in FIG. 8, in the sixth embodiment, the substrate plane is divided into a plurality of regions Ri. Then, the film thickness of the adjustment layer is measured at a plurality of positions Pi during the formation of the adjustment layer (for example, the first adjustment layer 15 or the adjustment layer 17 described above). Then, based on the measurement result of the film thickness of the adjustment layer at each of the plurality of positions Pi, the film thickness of the adjustment layer is adjusted for each region Ri corresponding to each of the plurality of positions Pi. Each position Pi is located in each corresponding region Ri, and the film thickness adjustment processing in each region Ri is performed based on the film thickness measurement result in the position Pi corresponding to each region Ri. By such processing, it is possible to equalize the in-plane distribution regarding the film thickness of the adjustment layer.

  Regarding the contents of the adjustment layer, the adjustment method of the film thickness, and the like, the contents described in the above embodiments can be similarly used.

  In addition, the film thickness measurement of the adjustment layer at the plurality of positions Pi may be performed by moving the film thickness measurement unit 30 (FIG. 2) during film formation, for example. Alternatively, the substrate may be moved (for example, translated or rotated). Alternatively, a plurality of the above-described film thickness measuring units 30 (FIG. 2) may be provided, and the film thickness of the adjustment layer at each position Pi may be measured using the plurality of film thickness measuring units 30. Alternatively, the light emitted from the light projecting unit 31 is changed in incident angle with respect to the first adjustment layer 15 using a galvano mirror or the like, and a plurality of light receiving positions are received at the reflected light receiving positions with respect to the incident light according to each of the plurality of incident angles. Each of the units 32 may be provided, and the light reflected at each of the plurality of positions Pi may be received by each light receiving unit 32.

  When adjusting the adjustment layer, the above-described various processes, that is, an additional formation process of the adjustment layer, a film thickness reduction process of the adjustment layer, or an optical film thickness change process of the adjustment layer by ultraviolet irradiation are performed for each region Ri. It only has to be done.

  For example, in the additional formation process, the vapor deposition process or the like may be repeatedly performed while changing the target area in a state where the area other than the target area Ri of the adjustment layer additional formation process is masked. The same applies to the film thickness reduction processing of the adjustment layer, and the etching processing or the like may be repeated while changing the target region while masking the region other than the target region Ri. The same applies to the optical film thickness changing process of the adjustment layer by ultraviolet irradiation.

<7. Other>
In each of the above embodiments, the first adjustment layer 15, the second adjustment layer 16, the adjustment layer 17 and the like are exemplified by the case where they are formed by vapor deposition. However, the present invention is not limited thereto, and may be formed by CVD or the like. Good.

  Moreover, in each said embodiment, although the case where the film thickness of the 1st adjustment layer 15 grade | etc., Formed in the actual light emission part of organic electroluminescent apparatus (1A etc.) was illustrated, it is not limited to this. For example, on the substrate plane, in addition to a place where each layer of the organic EL device 1A as a product is formed, a portion for forming only the first adjustment layer 15 is provided, and this portion is used as a dummy pattern dedicated to film thickness measurement. It may be.

  Moreover, in each said embodiment, although the case where a film thickness measurement was performed using the intensity | strength change of reflected light was illustrated, it is not limited to this. For example, the film thickness may be measured using a change in transmitted light intensity with respect to the dummy pattern.

1 is a cross-sectional view of an organic EL device according to a first embodiment. It is a schematic perspective view which shows a vapor deposition apparatus. It is a figure for demonstrating the principle of a film thickness measurement. It is sectional drawing of the organic electroluminescent apparatus which concerns on 2nd Embodiment. It is sectional drawing of the organic electroluminescent apparatus which concerns on 3rd Embodiment. It is sectional drawing of the organic electroluminescent apparatus which concerns on 4th Embodiment. It is sectional drawing of the organic electroluminescent apparatus which concerns on 5th Embodiment. It is a conceptual diagram which shows the vapor deposition apparatus 100B which concerns on 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A-1E Organic EL device 10 Board | substrate 11 1st electrode layer 12 Organic layer 13 2nd electrode layer 14 Cap layer 15-18 Adjustment layer 30 Film thickness measurement part 31 Light projection part 32 Light reception part 50 Ultraviolet irradiation part 100A, 100B Vapor deposition equipment (film deposition equipment)

Claims (11)

A method of manufacturing an organic EL device,
a) forming an organic layer including a light emitting layer;
b) forming an adjustment layer for adjusting the optical film thickness of the plurality of layers including the light emitting layer;
With
Said step b)
b-1) measuring the thickness of the adjustment layer during the formation of the adjustment layer;
b-2) adjusting the optical thickness of the adjustment layer based on the measurement result of the thickness of the adjustment layer;
A method for producing an organic EL device, comprising: In the manufacturing method of the organic electroluminescent apparatus of Claim 1,
The adjustment layer has a first adjustment layer and a second adjustment layer,
The step b-1) includes a step of measuring the thickness of the first adjustment layer during the formation of the first adjustment layer,
The method b-2) includes a step of additionally forming the second adjustment layer based on the measurement result of the film thickness of the first adjustment layer. In the manufacturing method of the organic electroluminescent apparatus of Claim 2,
The method of manufacturing an organic EL device, wherein the first adjustment layer and the second adjustment layer are made of different materials. In the manufacturing method of the organic electroluminescent apparatus of Claim 2,
The method of manufacturing an organic EL device, wherein the first adjustment layer and the second adjustment layer are made of the same material. In the manufacturing method of the organic electroluminescent apparatus of Claim 1,
The step b-2) includes a step of reducing the film thickness of the adjustment layer. In the manufacturing method of the organic electroluminescent apparatus of Claim 1,
The step b-2) includes a step of adjusting the optical film thickness of the adjustment layer by irradiating the adjustment layer with ultraviolet rays. In the manufacturing method of the organic electroluminescent apparatus in any one of Claims 1-6,
In the step b-1), the film thickness of the adjustment layer is measured by measuring the film thickness of the dummy pattern related to the adjustment layer. In the manufacturing method of the organic electroluminescent apparatus in any one of Claims 1-7,
In the step b-1), the change in the intensity of reflected light or transmitted light of the adjustment layer is measured during film formation of the adjustment layer, whereby the film thickness of the adjustment layer is measured. A method for manufacturing an organic EL device, which is characterized. In the manufacturing method of the organic electroluminescent apparatus of Claim 8,
In step b-1),
A first time corresponding to the last maximum value or the last minimum value in the change curve of the intensity of the reflected light or transmitted light, at least during the film formation period of the adjustment layer, is a period immediately before the film formation stop. A change in the intensity of the reflected or transmitted light is measured over a period of time included;
The film thickness of the adjustment layer is calculated using an actual measurement time from the first time to a scheduled film formation stop time and a theoretical value of the film thickness at the first time. Manufacturing method. In the manufacturing method of the organic electroluminescent apparatus of Claim 9,
In step b-1),
Of the film formation period of the adjustment layer, the change in intensity of the reflected light or transmitted light is measured over at least two extreme values immediately before the film formation stop in the change curve,
The film thickness of the adjustment layer is calculated using the actual measurement time from the first time to the scheduled film formation stop time, the theoretical value of the film thickness at the first time, and the measurement time interval between the two extreme values. A method for manufacturing an organic EL device. In the manufacturing method of the organic electroluminescent apparatus in any one of Claims 1-10,
The step b-1) includes a step of measuring the thickness of the adjustment layer at a plurality of positions during the formation of the adjustment layer,
The step b-2) is a step of adjusting the film thickness of the adjustment layer for each region corresponding to each of the plurality of positions, based on the measurement result of the film thickness of the adjustment layer at each of the plurality of positions. Having
A method for manufacturing an organic EL device.

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