JP2006016660A - Apparatus for forming organic thin film, and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus which can control the thickness of an organic film so as to precisely form a functional device with an organic thin film having a desired film thickness and film composition, with a simple motion mechanism. <P>SOLUTION: A measuring instrument for measuring the concentration of a doped material in the organic thin film formed on a structure comprises: a light source for irradiating the structure with a light having such a wavelength range as to include at least an exciting light, at least in a period of forming the film; a detecting means for detecting the fluorescence intensity emitted from the structure in response to the irradiated light, by receiving at least fluorescent light from the structure; and a measuring means for measuring the concentration of the doping material doped into the organic film, on the basis of the thickness of the organic thin film and the fluorescence intensity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to thin film formation and thin film control, and more particularly to an apparatus and method for forming an organic thin film functional element in which the thickness and composition of an organic thin film constituting the functional element are sensitive to element characteristics.

Organic EL devices, which are expected to become a large market for next-generation display devices generated from the organic electronics field, have high brightness, high efficiency, wide viewing angle, high-speed response, and thin display devices. Therefore, it has been attracting attention in recent years, and intensive research is being conducted toward realization by full color and long life.
As shown in FIG. 4, a general organic EL element is formed by forming a transparent conductive film 31 on a glass substrate 30, then forming organic thin films 32 to 34, and then laminating an electrode 35 on the surface of the organic thin film 34, Finally, the whole is protected by sealing with the can 36.
In the organic EL device fabricated in this way, when each organic thin film 32 to 34 functions as a hole transport layer, a light emitting layer, and an electron transport layer, a positive voltage is applied to the transparent conductive film 31 and a negative voltage is applied to the electrode 35. The organic thin film 33 as the light emitting layer emits light by electric shock, and the EL light 37 transmitted through the glass substrate 30 is emitted to the outside.

The transparent conductive film 31 generally uses an ITO (Indium-Tin Oxide) thin film. When the organic thin films 32 to 34 are laminated on the surface, a glass substrate 30 on which the transparent conductive film 31 is formed is prepared, and after the surface treatment of the transparent conductive film 31 is performed, the inside of the vacuum chamber of the organic thin film forming apparatus Install in.
At least one or more organic material evaporation source is disposed in the vacuum chamber, the transparent conductive film 31 of the installed glass substrate 30 is opposed to the organic material evaporation source, and the vacuum chamber has a predetermined pressure. Exhaust until.
When the organic material evaporation source is filled in advance with the organic material evaporation source and the organic material evaporation source is heated, the vapor of the organic evaporation material is released into the vacuum chamber.
When the stability of the vapor release rate is confirmed by the vapor deposition rate detection means for detecting the change in the natural frequency of the resonator due to the substance deposited on the crystal resonator, when the shutter disposed under the glass substrate 30 is opened, The vapor of the organic evaporation material reaches the transparent conductive film 31, and an organic thin film having a uniform thickness is formed on the surface.
Thus, if an organic thin film forming apparatus is used, it is possible to form an organic thin film with good film quality on the surface of the transparent conductive film 31 in a vacuum atmosphere.

By the way, in recent years, higher efficiency and longer life are expected for practical application to a wide range of organic EL element display devices. It is desired to solve the problems for improving the efficiency and extending the life of the organic EL element. One solution to this problem is to improve material performance. Depending on the organic evaporation material, it has specific HOMO (highest occupied orbit) and LUMO (lowest empty orbit) size, band gap, carrier mobility, glass transition temperature, etc. A variety of structures have been synthesized by organic synthesis for the purpose. In particular, intensive developments such as new light emitting materials utilizing triplet phosphorescence such as iridium complexes and new carrier transporting materials having higher carrier mobility than conventional ones have been made.
In addition to improving the performance of materials, as a problem to improve the efficiency and longevity of organic EL elements, the combination of the thickness of each functional layer constituting the organic EL element, laser dyes, etc. were mixed into the host material. Optimization of the overall device structure, such as the weight percent concentration of the doped host material in the doping type device, as well as the film thickness and film composition of each layer, has been performed.
An organic EL element is formed of a plurality of organic layers, and the weight of the role of each functional layer also depends on the film thickness. The device characteristics change greatly only by the film thickness deviating by several nm. Depending on the recombination region, the color purity, device lifetime, luminous efficiency, and current efficiency may change significantly.

In addition, the light-emitting layer of the organic EL element is often adjusted to a desired light-emitting characteristic by doping a host material made of a carrier transport material with a guest material that is a fluorescent material in a very small amount. Doping is performed by co-evaporating a host material and a guest material, and the doping concentration is determined by controlling the deposition rate of each material. For example, a host material is deposited at a rate of 1 nm per second, and a guest material is deposited at a rate of 0.01 nm per second to form a light emitting layer having 1% guest material. Since the doping concentration of the device manufactured in this way has a great effect on the efficiency and life of the organic EL device, the doping concentration is controlled with high accuracy.
As described above, in organic EL elements, it is well known that the film thickness and film composition have a great influence on the optical characteristics. Therefore, a technique for accurately fabricating an element structure with a desired film thickness and doping concentration is important. Positioned as technology.

As a conventional film thickness control method, a crystal oscillator method that detects a film thickness from a change in the natural frequency of a crystal oscillator is generally used. In the crystal resonator method, a crystal resonator is disposed in a film forming chamber, a change in the amount of material deposited on the crystal resonator is detected from the natural frequency of the resonator, and a component formed on an actual structure is formed. In this method, the film thickness is controlled by indirectly estimating the film thickness on the actual structure.
The crystal resonator method is used as a composition control means in the film also in the production of a doping type element. This is indirectly achieved by measuring the deposition rate of the doping material and the host material with the same crystal resonator as described above, controlling the deposition rate of the doping material, and further controlling the deposition rate of the host material. It predicts and controls the composition of the device thin film on the structure.

However, the vapor of the organic material has characteristics such as low heat conduction peculiar to organic matter and high vapor pressure, and there is a problem that the deposition rate control and the evaporation distribution control are relatively difficult. In addition, when the evaporation surface falls due to material consumption during film formation in the evaporation source, the evaporation distribution changes, so an indirect film thickness measurement means causes a film thickness error. This is a serious problem in the production of an organic functional device in which the film thickness or doping concentration greatly affects the characteristics. In addition, an element manufactured by such film formation control also has a problem of poor reproducibility and low device yield.
Furthermore, because the crystal oscillator measures the film thickness from the frequency change caused by the mass load, it causes oscillation failure when the mass load range limit of the crystal oscillator is exceeded. As a result, there is a problem in controlling the film thickness when forming an organic film with high accuracy.
In particular, in an element manufacturing apparatus in mass production, more sufficient devices are required from the viewpoints of both maintainability and control accuracy.

In view of the above-mentioned problems, Patent Documents 1 to 3 disclose apparatuses or methods using optical thin film control means.
In Patent Document 1, an organic EL element manufacturing apparatus includes an ultraviolet irradiation means and a fluorescence intensity measurement means, and the organic molecules formed on the substrate are measured by irradiating the evaporation molecules of the organic material with ultraviolet rays to measure the fluorescence intensity of the evaporation molecules. The thickness of the material film is determined.
Patent Document 2 discloses a movable member for monitoring, a means for optically sensing and controlling the thickness of the organic material, a means for optically sensing and controlling the concentration of the dopant material contained in the organic material, and a movable member cleaning means. And monitoring and controlling the organic layer deposition process.
Patent Document 3 irradiates an organic thin film with light containing ultraviolet light, obtains the film thickness from the intensity of fluorescence generated by the organic thin film, and measures the film thickness distribution of the organic thin film.
JP 2000-294372 A JP 2003-7462 A JP 2003-279326 A

In the means disclosed in Patent Document 1, the reproducibility of the composition is confirmed because the doping deposition rate is indirectly controlled in the same manner as the film thickness measurement by the conventional crystal resonator, not the doping concentration on the actual structure. There was a problem that could only be done by comparing the characteristics of the device.
Since the means disclosed in Patent Document 2 does not measure the structure during film formation, there is a problem in that changes in film thickness and doping concentration during film formation cannot be measured. Furthermore, since a means for sensing the thickness of the organic material and a means for sensing the concentration of the dopant material exist independently, and a complicated mechanical and electrical mechanism for operating the movable member is required, There was a disadvantage that a large space had to be secured in the vapor deposition apparatus.
The means disclosed in Patent Document 3 has the disadvantage that the film thickness cannot be measured from the fluorescence intensity because the doping material absorbs the fluorescence of the host material when a doping type device is to be produced.

Therefore, there is a need to solve these problems and to easily measure and control the thickness of the actual substrate and the actual doping concentration in manufacturing the doping element.
Therefore, an object of the present invention is to provide an apparatus that realizes film thickness control of an organic film capable of accurately forming an organic thin film functional element having a desired film thickness and film composition by a simple operation mechanism. To do.

  A first aspect of the present invention is a measuring apparatus for measuring a doping concentration in an organic thin film of a structure, and a light source that projects irradiation light in a wavelength range including at least excitation light onto the structure at least during film formation Detecting means for receiving at least fluorescence from the structure with respect to irradiation light and obtaining fluorescence intensity of the structure, measuring the thickness of the organic thin film and the concentration of the doping material doped in the organic film based on the fluorescence intensity It is a measuring device comprising a concentration measuring means. In addition, the concentration measuring means measures the doping concentration based on the intensity of the fluorescence with respect to the thickness of the organic thin film.

According to a second aspect of the present invention, there is provided an organic thin film forming apparatus for forming an organic thin film on a structure, and at least a light source for projecting irradiation light in a wavelength range including a wavelength of excitation light onto the structure during film formation A light detector that receives light from the structure with respect to the irradiation light, performs wavelength separation and light intensity detection, and a measurement device connected to the light detector, and the measurement device is output from the light detector First observation means for observing the fluorescence wavelength and fluorescence intensity of the structure from the light wavelength and light intensity to be measured, first measurement means for measuring the thickness of the organic thin film from the output of the first observation means, and first It is an organic thin film formation apparatus which has the 2nd measurement means to measure the doping concentration in an organic thin film from the output of this observation means.
Further, the photodetector simultaneously receives the fluorescence of the structure with respect to the excitation light included in the irradiation light and the reflected light or transmitted light with respect to the irradiation light, and the measuring device determines from the light wavelength and light intensity output from the light detector. The structure has second observation means for observing the absorption wavelength and absorption intensity of the structure, and third measurement means for measuring the thickness of the organic thin film from the output of the second observation means. Further, the first measuring means calculates the thickness of the organic thin film by comparing the output of the first observing means with the first theoretical value of the fluorescence characteristic for the film thickness including at least the target film thickness value. One theoretical value of the fluorescence characteristic is a value calculated by using the dependence characteristics of the light intensity of the excitation light, the fluorescence intensity of the structure, and the thickness of the organic thin film.

Still further, the second measuring means calculates the doping concentration of the organic thin film by comparing the output of the first observing means with the second or third fluorescent characteristic theoretical value for the doping concentration including at least the target doping concentration. Then, the second theoretical value of the fluorescence characteristic is a value calculated by utilizing the dependency specification between the fluorescence wavelength of the doped doping material and the doping concentration in the organic thin film. Here, the third theoretical value of the fluorescence characteristic is a value calculated using the dependence characteristics of the fluorescence intensity of the doped doping material, the thickness of the organic thin film, and the doping concentration in the organic thin film. In the second theoretical value of fluorescence characteristics, the doping concentration in the organic thin film is a value calculated based on the fact that the fluorescence wavelength shifts to the longer wavelength side as the doping concentration in the organic thin film increases. . On the other hand, in the third theoretical value of fluorescence characteristics, the doping concentration in the organic thin film was a value calculated based on the monotonous increase in the fluorescence intensity with respect to the thickness of the organic thin film.
The third measuring means calculates the film thickness of the organic thin film by comparing the output of the second observing means with the first or second absorbed light theoretical value for the film thickness including at least the target film thickness value. The first theoretical value of absorbed light is dependent on the light intensity of the predetermined wavelength light in the irradiation light, the light intensity of the wavelength light in the reflected or transmitted light from the structure, and the thickness of the organic thin film. The second theoretical value of absorbed light is calculated based on the spectral characteristics of the irradiated light, the spectral characteristics of reflected or transmitted light from the structure, and the dependence on the thickness of the organic thin film. It was set as the value calculated.

  According to a third aspect of the present invention, in the second aspect, a second light source that projects irradiation light in a wavelength range including at least excitation light onto the organic material immediately before being formed in the structure, and the organic material A second optical detector that performs wavelength separation and light intensity detection of the received light and outputs the result of wavelength separation and light intensity detection to the measurement device. A third observation means for observing the fluorescence wavelength and fluorescence intensity of the organic material from the wavelength and light intensity output from the photodetector, and a doping concentration in the organic thin film from the output of the third observation means. An organic thin film forming apparatus having four measuring means. Further, the fourth measuring means measures the doping concentration of the organic thin film by comparing the output of the third observing means with the fourth or fifth theoretical value of the fluorescence characteristic for the doping concentration including at least the target doping concentration. The fourth theoretical value of the fluorescence characteristic is a value calculated by using the dependency specification of the fluorescence wavelength of the doping material in the organic material and the doping concentration of the organic thin film, and the fifth theoretical value of the fluorescence characteristic is the organic material The value calculated based on the dependence characteristics of the fluorescence intensity of the doping material, the thickness of the organic thin film, and the doping concentration of the organic thin film.

  Further, in the second or third aspect, the control device comprises an evaporation source for depositing an organic material on the structure, a shutter for shielding the evaporation source from the structure, and a control device connected to the measurement device. Based on the output from the measuring device, the evaporation source is controlled so that the thickness or doping concentration of the organic thin film becomes a desired value, and the deposition is terminated when the organic thin film reaches the desired thickness. The evaporation source or shutter was controlled.

  The light source projects light to the structure via an optical fiber having a light projecting end disposed close to the structure and the other end connected to the light source, and the photodetector has a light receiving end disposed close to the structure. Light is received from the structure via an optical fiber having the other end connected to a photodetector. Here, the optical fiber is a Y-branch-shaped optical fiber in which the light projecting / receiving end is disposed close to the structure and the other end is connected to the light source and the light detector. Projecting light and receiving light from the structure at the same time.

  Furthermore, the irradiation structure is irradiated with the actual structure during film formation.

  According to a fourth aspect of the present invention, there is provided an organic thin film forming method for forming an organic thin film on a structure. At least during the film formation, the structure is irradiated with excitation light to receive light from the structure, and light fluorescence. Perform the first observation to observe the wavelength and fluorescence intensity, or the second observation to observe the absorption wavelength and absorbed light intensity of the structure, and measure the thickness of the organic thin film from the result of the first observation Perform the first measurement and perform the second measurement to measure the doping concentration of the organic thin film from the result of the first observation, or the third measurement to measure the thickness of the organic thin film from the result of the second observation This is an organic thin film forming method. Furthermore, the result of the first, second or third measurement is fed back to the evaporation source control of the organic thin film.

  A fifth aspect of the present invention is a method for forming a doping element in an organic thin film functional element, wherein the structure is irradiated with light in a wavelength range including excitation light of the doping material, and fluorescence of the doping material by the excitation light is observed. Then, the doping concentration of the organic thin film is measured from the observation results, the thickness of the organic thin film is measured from the light intensity of reflected light or transmitted light irradiated to the structure, and the doping concentration and thickness of the organic thin film are measured. Forming method to be controlled.

  A sixth aspect of the present invention is a measuring apparatus for measuring a doping concentration in an organic thin film of a structure, and at least during the film formation, a light source that projects irradiation light in a wavelength range including at least excitation light onto the structure A measuring device comprising a detecting means for receiving at least fluorescence from the structure with respect to irradiation light and obtaining a fluorescence wavelength of the structure, and a concentration measuring means for measuring the concentration of the doping material doped in the organic film based on the fluorescence wavelength. is there. Further, the doping concentration is measured based on the fact that the fluorescence wavelength shifts to the longer wavelength side as the doping concentration increases.

  According to the present invention, it is possible to improve the accuracy of film thickness measurement / control and doping concentration measurement / control in organic material film formation with a simple configuration. In addition, since it is possible to select a plurality of types of film formation measurement and film formation control with the same apparatus by switching programs, it contributes to the improvement of the performance of the organic thin film forming apparatus.

FIG. 1 shows an organic thin film forming apparatus for explaining an embodiment of the present invention, which has a vacuum chamber 1. A plurality of independent organic evaporation sources 4 are disposed on the bottom surface of the vacuum chamber 1, and a substrate holder 3 is disposed on the ceiling side. Although two organic evaporation sources 4 are provided in the figure, the number of evaporation sources may be appropriately selected. Each organic evaporation source 4 evaporates or sublimates the organic evaporation material 5 filled in the container, and generates a vapor 17 in the vacuum chamber 1. For the organic evaporation source 4, for example, an evaporation source that winds a resistance heater around a crucible made of ceramics and generates steam by energization heating may be used. Alternatively, other heating methods, materials, and structures may be used. In the container, for example, Alq3 [Tris (8-hydroxy-quinoline) alminium] or α-NPD [N, N'-di-α-naphthyl-] which is a powdery sublimable organic compound shown in FIG. 3A and FIG. 3B. An organic evaporation material such as N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine may be filled.
A substrate 2 is placed on a close position under the substrate holder 3, and a mask 6 for restricting a film formation region is placed under the substrate 2. Hereinafter, the portion constituting the organic thin film functional element deposited on the substrate 2 is hereinafter referred to as a structure including the element forming stage. If the combinatorial mask disclosed in Japanese Patent Application No. 2003-390319 proposed by the applicant of the present application is used for the mask 6, a plurality of elements can be formed efficiently.

  A shutter 7 that shields the vapor is disposed between the substrate 2 and the organic evaporation source 4 so as to be openable and closable, and is controlled by the control device 16. Further, a deposition rate detecting means 15 for detecting the evaporation rate of the vapor 17 is disposed between the substrate evaporation sources. For the vapor deposition rate detecting means 15, for example, a quartz resonator is used as a suitable means capable of detecting a time-series change in the amount of deposited material, and the vapor deposition rate is determined from the change in the natural frequency of the quartz resonator. What is necessary is just to detect. The vapor deposition rate detection means 15 outputs the vapor deposition rate to the control device 16, and the control device 16 controls the evaporation source 4 to stabilize the evaporation rate.

  Near the glass substrate 2, a bundled tip 11 of the Y-branch optical fiber 8 is disposed. The branched optical fiber 9 at one end of the Y-branched optical fiber 8 is connected to a light source 12, and the optical fiber 10 at the other end is connected to a photodetector 13. The light source 12 has means for selecting and projecting light of an arbitrary wavelength range or light of an arbitrary single wavelength, and the light detector 13 is a spectroscope that senses light intensity by wavelength-separating the received light. It has light intensity sensing means such as a photometer. The optical fiber 8 irradiates the glass substrate 2 with excitation light from the tip 11, and condenses the fluorescence excited by the excitation light or the reflected reflected light at the tip 11 of the optical fiber 8. Light irradiation and light collection may be performed, for example, according to a dead point of a structure formed on the substrate 2. In the embodiment, the film forming accuracy is improved by actually measuring the film thickness or material composition of the actual substrate. However, a monitor glass is prepared, and the optical fiber 8 is installed in the vicinity of the monitor glass to perform measurement and control. It is also possible to do this. The light detector 13 is connected to a measuring device 14, and the measuring device 14 is connected to a control device 16.

The measuring device 14 has means for observing a time series change of light incident on the photodetector 13 and means for measuring a film thickness or a doping concentration based on the time series change. The measurement is performed by sequentially comparing the pre-programmed theoretical value with the output of the photodetector 13 as an actual measurement value.
For example, if the structure is irradiated with excitation light during the formation of the structure constituting the organic thin film functional element, electrons in the organic thin film are excited to emit fluorescence, but the fluorescence intensity is the same as the light intensity of the excitation light. There is a feature that increases depending on the thickness of the organic thin film. In the case where the organic thin film functional element is a doping type element, the central fluorescence wavelength of the doping material has a characteristic that it changes by affecting the composition ratio of the doping material to the host material. The composition ratio of the doping material to the host material can also be calculated from the fluorescence intensity of the doping material with respect to the film thickness. By programming these dependency characteristics in the measurement device 14 in advance, it becomes possible to calculate the film thickness and the doping concentration at each fluorescence intensity and each central fluorescence wavelength. Hereinafter, the means for observing the time series change of fluorescence is referred to as the first observing means, and the means for calculating the thickness of the organic thin film based on the first observing means is the first measuring means, the first observing means. The means for calculating the doping concentration based on the above is referred to as a second measuring means.

Further, it is a well-known technique that when light is applied to a structure during film formation, the absorbed light changes depending on the film thickness. The measuring device 14 can also calculate the film thickness from the time-series change of the absorbed light by previously programming the dependence characteristics of the absorbed light and the film thickness. Hereinafter, the means for observing the time series change of the absorbed light is referred to as second observation means, and the means for calculating the thickness of the organic thin film from the absorbed light is referred to as third measurement means. The first to third measuring means provided in the measuring device 14 have independent programs, and perform a plurality of measurements at the same time by selecting specific means by switching programs or by simultaneously executing the programs. It is possible.
In order to select and observe fluorescent light or absorbed light from light incident on the light detector 13, element characteristics such as a base structure of a structure, a laminated structure, and a film forming material are input to a program in advance, and a specific wavelength is selected. Alternatively, a specific wavelength range may be selected and a time series change may be observed. Therefore, it is desirable to employ light that does not include the fluorescence wavelength range as the irradiation light.

  The control device 16 controls the evaporation source 4 or the shutter 7 based on the actually measured value of the film thickness or doping concentration output from the measurement device 14. Specifically, a target range is set in advance for the theoretical value calculated by the measuring device 14 using the program, and when the measured value falls within the target range or when the measured value falls within the target range. What is necessary is just to control so that film-forming may be complete | finished.

  By using the Y branch optical fiber 8 in the embodiment, it is possible to make one introduction port into the vacuum chamber, which contributes to the simplification of the configuration. However, the optical fiber 9 and the photodetector 13 that are led out from the light source. The optical fibers 10 to be introduced into the optical fiber 10 may be provided independently to provide two introduction ports. In this case, the light emission position and the incident position may be provided separately. In the embodiment, the photodetector 13 receives the reflected light, but the optical fiber 8 may be disposed so as to receive the transmitted light. It is also conceivable to arrange a condensing lens or a wavelength cut filter between the optical fiber 10 connected to the light detector 13 and the substrate 2.

FIG. 2 shows an organic thin film forming apparatus for explaining another embodiment of the present invention. The same parts as those of the organic thin film forming apparatus shown in FIG.
The apparatus shown in FIG. 2 includes a second light source 20, an optical fiber 22 that is derived from the second light source 20 and irradiates the organic material vapor with excitation light, a second photodetector 21, and a second photodetector 21. And an optical fiber 23 for receiving the fluorescence of the organic material vapor. In the figure, light is emitted and incident by the optical fiber 22 and the tip 24 of the optical fiber 23, but the emission position and the incident position may be provided separately. In the figure, four optical fibers are bundled and introduced, but each optical fiber may be introduced independently. Moreover, although the 2nd light source 20 is provided independently, you may connect the light source 12 and the optical fiber 22, and may make one light source. In this case, the substrate 2 and the organic material vapor may be irradiated with light having the same wavelength, or a wavelength cut filter may be provided at the tip of one optical fiber to remove a specific range of wavelengths from the irradiated light.

  The measuring device 25 includes a third observation means and a third observation means for observing a time-series change in fluorescence emitted by vapor immediately before deposition on the structure based on the output of the second photodetector 21. And a fourth measuring means for measuring the vapor doping concentration. The measuring device 25 is also provided with the first and second measuring means, and processes the output of the photodetector 13 and the output of the second photodetector 21 independently. The fourth measurement means is the same as the second measurement means in that the theoretical value is calculated using a program inputted in advance and the theoretical value and the actual measurement value are sequentially compared, but the actual measurement value is the doping concentration of the organic material vapor. Is different in that.

  The control device 26 controls the evaporation source 4 based on the output of the fourth measuring means. The control device 26 may output a control signal appropriately processed based on the outputs of the first to fourth measuring means.

  Hereinafter, although the Example which produced the organic thin film functional element using the organic thin film forming apparatus shown in FIG. 1 or FIG. 2 is described, this invention is not limited to a following example.

  In the first example, α-NPD, which is a diamine compound having a chemical structural formula shown in FIG. 3A, is used as a hole transporting material, and Alq3 shown in FIG. This is an example in which an organic EL element having a single hetero structure as a transporting light-emitting material was manufactured.

1, the substrate holder 3 is disposed at a position where the distance between the substrate evaporation sources is about 200 mm, the substrate 2 is disposed on the substrate holder 3, and the degree of vacuum is 6 in the vacuum chamber 1. Vacuum exhausted to 0.0 × 10 ⁻⁶ Torr. The substrate 2 was a 40 mm × 40 mm glass substrate in which a transparent conductive film 31 made of ITO having a thickness of 130 nm was formed on the glass surface by patterning 2.0 mm × 2.0 mm × 4. If the number of ITO patterns is increased, devices having different structures or compositions can be produced by the number of ITO patterns.

The organic evaporation source 4 is a rotary crucible by resistance heating in which a tungsten coil is wound around an alumina container. An organic evaporation source 4A filled with α-NPD, which is a hole transporting material, and an organic evaporation source 4B filled with Alq3, which is an electron transporting luminescent material, are used as a binary evaporation source adjacent to each other. The loading depth was 4 mm.
The winding coil of the organic evaporation source 4A is energized and heated by a current power source (not shown), and feedback control is performed from the deposition rate detecting means 15 to the current power source so that the deposition rate of α-NPD is constant at 0.2 nm / sec. It was.

When the evaporation rate of α-NPD was stabilized at 0.2 nm / sec, the vapor shielding shutter 7 disposed under the substrate holder 3 was opened, and resistance heating evaporation of α-NPD was started. During film formation, the tip 11 of the Y branch optical fiber 8 was irradiated with excitation light having a wavelength of 300 nm projected from the light source 12. When electrons in the structure excited by light irradiation return to the ground state, a light emission phenomenon occurs and fluorescence is emitted from the structure. Therefore, the Y-branch optical fiber 8 is structured at the same position as the excitation light irradiation. The fluorescent light and the reflected light of the excitation light are received. A spectrophotometer is used for the photodetector 13, and the Y branch optical fiber 8 makes the received light incident on the spectrophotometer 13.
When α-NPD returns to the ground state, fluorescence having a maximum value is emitted in the vicinity of a wavelength of 430 nm. Therefore, the measuring device 14 observed a time series change of light in the vicinity of a wavelength of 430 nm input from the spectrophotometer 13. The measurement device 14 is programmed in advance with the element characteristics of the structure irradiated with the excitation light, the light intensity of the excitation light, the light intensity of the fluorescence, and the dependence characteristics of the thickness of the organic thin film in the structure. Using the first observation means and the first measurement means, the theoretical value calculated by the program and the actual measurement value input from the spectrophotometer 13 were sequentially compared to perform film thickness measurement.

The solid line in FIG. 5 shows the theoretical characteristics of fluorescence when the α-NPD vapor 17 forms a 60 nm thin film on the surface of the ITO film 31 of the substrate 2, and the horizontal axis represents wavelength and the vertical axis represents light intensity. For the sake of explanation, the theoretical characteristic of a film thickness of 60 nm is exemplified, but the theoretical characteristic of fluorescence can be calculated for a desired film thickness. In the first embodiment, since an α-NPD film having a thickness of 60 nm is formed, a time-series change in light intensity in the vicinity of a wavelength of 430 nm is observed, and the light intensity falls within the target range of fluorescence intensity shown by the solid line in FIG. At the time, the film formation was terminated by the control device 16.
The broken line in FIG. 5 indicates the light intensity of the absorbed light in the 60 nm α-NPD film. When detecting the film thickness of the α-NPD film by light absorption, the second observation means and the third measurement means are used, and the light intensity falls within the target range of the absorption light intensity indicated by the broken line in FIG. The film formation may be terminated at this point. In the second observation means, the spectral characteristic may be observed using the wavelength range from the ultraviolet to the visible light region as irradiation light, or a change in light intensity at a single wavelength may be observed. The measuring device 14 and the control device 16 are characterized by being able to appropriately select between film thickness control by fluorescence characteristics and film thickness control by light absorption characteristics by switching programs.

  Subsequently, Alq3 which is an electron transporting light emitting layer was performed on the glass substrate 2 on which the α-NPD was formed in the same manner as the evaporation of the α-NPD film. First, the organic evaporation source 4B was energized and heated by a current power source (not shown), and feedback control was performed by the deposition rate detecting means 15 so that the deposition rate of Alq3 was constant at 0.2 nm / sec. After stabilizing the deposition rate of Alq3 at 0.2 nm / sec, the shutter 7 arranged under the substrate holder 3 was opened, and resistance heating deposition of Alq3 was started.

During the film formation, the substrate 2 was irradiated with excitation light having a wavelength of 400 nm. When Alq3 returns to the ground state, fluorescence having a maximum value in the vicinity of a wavelength of 535 nm is emitted.
The solid line in FIG. 6 shows the theoretical characteristics of fluorescence in the Alq3 film 48 nm, with the horizontal axis representing wavelength and the vertical axis representing light intensity. For the sake of explanation, the theoretical characteristic of a film thickness of 48 nm is exemplified, but the theoretical characteristic of fluorescence can be calculated for a desired film thickness. For the film thickness measurement, the first observation means and the first measurement means were used in the same manner as the formation of the α-NPD film, and the time series change of the light intensity in the vicinity of the wavelength of 535 nm was observed. In the example, in order to produce an Alq3 film having a thickness of 48 nm, the film formation is terminated when the light intensity falls within the target range of the fluorescence intensity shown by the solid line in FIG.

FIG. 7 shows a correlation diagram between the thickness of the Alq3 film and the fluorescence intensity of Alq3. The figure shows the results of actual measurement of the fluorescence intensity at each film thickness, and it can be seen that the film thickness and the fluorescence intensity are correlated as described above. The program of the measuring device 14 may be input with the correlation shown in the linear regression of the same figure as the theoretical value obtained by actual measurement.
The broken line in FIG. 6 indicates the light intensity of the absorbed light. When the film thickness is controlled by the light absorption, the program may be switched as in the case of forming the α-NPD film.
Thereafter, the glass substrate 2 on which α-NPD and Alq3 were formed with various film thicknesses was transported and placed on a cathode metal vapor deposition substrate holder (not shown) by a substrate transport mechanism (not shown) mounted in the vacuum chamber 1. A cathode metal vapor deposition mask (not shown) having at least four 2.0 mm × 5.0 mm unit openings is disposed in the vicinity of the cathode metal vapor deposition substrate holder.

  Although aluminum metal is used as the cathode metal material, LiF (lithium fluoride), a lithium compound known as a low work function, was introduced as an intermediate layer between the organic thin film and the aluminum metal. Lithium fluoride is placed in a vapor deposition boat made of molybdenum material, and feedback control is performed by a vapor deposition rate detection means using a crystal resonator so that the vapor deposition rate is constantly stabilized at 0.01 to 0.02 nm / sec. It was. After the deposition rate was stabilized, a cathode metal deposition shielding shutter (not shown) was opened, and resistance heating deposition was performed on the Alq3 film so as to have a film thickness of 0.5 nm.

  Next, wire-shaped aluminum metal is placed on a tungsten filament coil, the filament is energized and heated, and the deposition rate is detected using a quartz crystal so that the deposition rate is stabilized at 1.0 to 1.1 nm / sec. Feedback control was performed by means. After the deposition rate was stabilized, a cathode metal deposition shielding shutter (not shown) was opened, and resistance heating deposition was performed so that the film thickness became 100 nm.

As a result of measuring luminance-voltage characteristics, luminous efficiency-voltage characteristics, and current efficiency-voltage characteristics, which were the element characteristics of the fabricated organic EL, the element characteristics were good and the reproducibility of the film thickness was also good. . Even when the organic EL device was manufactured by changing the vapor deposition rate in the above example, as a result of being able to follow the change in the evaporation distribution due to the change in the vapor deposition rate, a device with good reproducibility of the optical characteristics could be manufactured.
As described above, when the present invention is used, there is no occurrence of a film thickness measurement error due to a change in the evaporation distribution due to the lowering of the crucible evaporation surface, or a change in the evaporation distribution due to a fluctuation in the evaporation rate due to a relatively high vapor pressure. It became possible to conduct research and development such as analysis and optimization of reliable organic EL element structures.

  In the second embodiment, the organic thin film forming apparatus shown in FIG. 1 is used, and the electron transporting light-emitting material of the element manufactured in the first embodiment is doped with DCM2 having the chemical structural formula shown in FIG. 3C. This is an example of manufacturing an organic EL element. The apparatus configuration in the second embodiment is the same as that in the first embodiment except that three organic evaporation sources 4 are prepared.

The organic evaporation source 4A is filled with α-NPD which is a hole transporting material, the organic evaporation source 4B is filled with Alq3 which is an electron transporting luminescent material, and the organic evaporation source 4C is an orange doping material. The depth at which DCM 2 was filled and each organic evaporation material 5 was loaded was 4 mm.
The method of depositing α-NPD in any film thickness on the ITO surface formed on the glass substrate as the element structure is the same as in the first embodiment, and the deposition rate of α-NPD is 0.2 nm / sec and 60 nm. The film formation was controlled by controlling the optical film thickness so that the film thickness was as follows.
Thereafter, the organic evaporation source 4B filled with Alq3 which is a host material and the organic evaporation source 4C filled with DCM2 which is a doping material are energized and heated, and the evaporation source 4 is adjusted to a desired doping concentration by the deposition rate detecting means 15. Controlled. In the second embodiment, Alq3 having a DCM2 doping concentration of 0.5 wt% was formed, so that the deposition rate of Alq3 was 0.2 nm / sec and the deposition rate of DCM2 was 0.001 nm / sec. When each deposition rate is stabilized, the vapor shielding shutter 7 disposed under the substrate 2 is opened, and film formation on the α-NPD film is started.

  During film formation, the substrate 2 was irradiated with light having a wavelength of 400 nm, which is the absorption wavelength of Alq3, from the tip 11 of the Y-branch optical fiber 8. If the Alq3 single layer is excited by the excitation light, fluorescence emission having a peak in the vicinity of a wavelength of 530 nm is exhibited. However, in the second embodiment, since DCM2 is doped, energy transfer to DCM2 occurs. This is because Alq3 has a light absorption band near the wavelength of 530 nm, and this phenomenon is well known. For this reason, the incident light to the photodetector 13 has a small fluorescence emission derived from Alq3, and an orange fluorescence emission having an emission peak in the vicinity of 630 nm derived from DCM2 is observed. FIG. 8 shows the light intensity of reflected light and fluorescence when Alq3 is doped with 0.5 wt% DCM2, the horizontal axis indicates the wavelength, and the vertical axis indicates the light intensity. From the figure, it can be seen that light emission around a wavelength of 530 nm is not observed and is absorbed by DCM2. Because of this phenomenon, it is difficult to implement the first measuring means for reading the thickness of the host material from the change in the fluorescence intensity of the host material, so it is effective to use the third measuring means for controlling the film thickness of the doping element. is there. In the second embodiment, the host material is considered as the absorption film, and the film thickness is measured from the time-series change of the interference light of the absorption film reflected when the excitation light from the light source is irradiated onto the substrate being formed. did.

  The vertical axis of FIG. 9 shows the change in reflectance when the substrate 2 being deposited is irradiated with light having a wavelength of 400 nm, and the horizontal axis shows the film thickness. The measurement device 14 is pre-programmed with the correlation between the film thickness and the reflectance shown in FIG. 9, and sequentially compares the theoretical value calculated by the program with the actual measurement value input from the spectrophotometer 13. The film thickness was measured using the second observation means and the third measurement means. FIG. 8 shows a time-series change of light actually incident on the spectrophotometer 13. In the second embodiment, since an Alq3 film having a DCM2 doping concentration of 0.5 wt% is formed to 48 nm, a time series change of light intensity in the vicinity of a wavelength of 400 nm is observed, and within the target range of reflectance shown in FIG. At this point, the film formation was terminated. In the embodiment, the time series change of the single wavelength light is observed, but the wavelength range of the irradiation light may be widened and the control by the spectral characteristics may be performed.

  When the doping concentration is constant, the fluorescence intensity of the doping material increases in proportion to the film thickness. Therefore, it is possible to measure the doping concentration based on the dependency of the fluorescence intensity and film thickness of the doping material. In the second embodiment, the above characteristics are preliminarily input to the measuring device 14 and the theoretical values calculated by the program and the actual values input from the spectrophotometer 13 using the first observing means and the second measuring means. The doping concentration was controlled by sequentially comparing Although the measured value of the film thickness is necessary for controlling the doping concentration, the output of the second measuring means may be used as the measured value. The doping concentration is measured and controlled simultaneously with the measurement and control of the film thickness, and the control device 16 processes the output of the third measuring means and the output of the second measuring means simultaneously.

FIG. 10 is a correlation diagram between the thickness of the Alq3 film having a DCM2 doping concentration of 0.5 wt% and the fluorescence intensity of DCM2, and the horizontal axis represents the light intensity on the vertical axis. The figure shows the results of actual measurement of the fluorescence intensity of the doping material at each film thickness, and it can be seen that the film thickness and the fluorescence intensity are correlated as described above. The program of the measuring device 14 may be input with the correlation shown in the linear regression of the same figure as the theoretical value obtained by actual measurement.
Although FIG. 10 shows the correlation between the film thickness and the fluorescence intensity at a single doping concentration, in practice, the correlation can be plotted for a plurality of doping concentrations. Therefore, using the correlation at the desired doping concentration, it is possible to control the doping to be terminated when the CDM2 fluorescence intensity for the known Alq3 film thickness reaches a predetermined value.
In FIG. 10, the horizontal axis represents the film thickness and the vertical axis represents the fluorescence intensity with the doping concentration as a fixed parameter. For example, the horizontal axis represents the fluorescence intensity and the vertical axis represents the film thickness as a fixed parameter. A correlation diagram showing the doping concentration may be used.
Furthermore, a three-dimensional correlation diagram having three axes of film thickness, fluorescence intensity, and doping concentration, and programming using the correlation as a table or function can be used.
In either method, the correlation between the film thickness and the fluorescence intensity for the desired doping concentration is programmed, the current doping concentration is calculated from the measured fluorescence intensity, and the calculated doping concentration reaches the theoretical value. It only has to stop doping sometimes.

Although the doping concentration was measured by measuring the fluorescence intensity of the doping material in the examples, the phenomenon that the emission peak wavelength shifts to the longer wavelength side as the doping concentration increases, which is a property unique to the doping material, is used. Even so, the doping concentration can be measured. At the doping concentration in the second embodiment, the central fluorescence wavelength of the doping material is 630 nm. Referring to FIG. 8, since the emission of DCM2 is observed in the vicinity of a wavelength of 630 nm, the doping concentration may be controlled so that the emission peak always has a wavelength of 630 nm.
After the formation of the organic material, as in the first embodiment, lithium fluoride was deposited at a deposition rate of 0.01 to 0.02 nm / sec and a thickness of 0.5 nm, and the deposition rate was 1.0 to 1.1 nm. / sec, 100 nm-thick aluminum metal vapor deposition was performed.

  Since the film thickness and the doping concentration can be observed simultaneously by the above embodiment, it is possible to perform highly accurate film formation control with a simple configuration. The produced doping type organic EL device had good reproducibility of luminance-voltage characteristics, luminous efficiency-voltage characteristics, and current efficiency-voltage characteristics, which were element characteristics, and good reproducibility of doping concentration.

The third embodiment is an example in which an organic EL element having a structure equal to the doping type organic EL element manufactured in the second embodiment is manufactured using the organic thin film forming apparatus shown in FIG.
The production of the α-NPD film, the aluminum cathode metal, and the formation of the lithium fluoride intermediate layer are the same as those in the first and second embodiments, and thus the description thereof is omitted.

  The third embodiment is different in that the output from the second photodetector 21 is used to control the doping concentration, but the film formation conditions and the film thickness control means are the same as in the second embodiment. The measuring device 25 observed the fluorescence intensity of the organic material vapor based on the output of the second photodetector 21, and measured the doping concentration by sequentially comparing the preprogrammed theoretical characteristics with the actual measurement values. The control device 26 processed the film thickness and doping concentration output from the measurement device 25 and controlled the evaporation source 4 and the shutter 7. As for the organic thin film element fabricated in the third example, the luminance-voltage characteristic, luminous efficiency-voltage characteristic, and current efficiency-voltage characteristic were measured, and the reproducibility of the element characteristic was good.

  The above-described embodiments and examples can be modified based on the technical idea of the present invention. In the above embodiment, an example of manufacturing an organic EL element is given, but it can also be used for manufacturing other organic thin film functional elements. For example, the present invention may also be used for an organic thin film transistor manufacturing process that has been focused on in recent years or an organic solar cell manufacturing process that is expected to be applied in the future. The organic EL elements used as the above examples have a single heterostructure, but usually the organic EL element structure has many laminated structures having further functional layers, and may be used for this. Moreover, in the said Example, although it utilizes as a film thickness measurement and control meter in the vapor deposition apparatus for research and development, it can also install and utilize also in a mass production apparatus.

Schematic 1 of the organic thin film forming apparatus of the present invention Schematic diagram 2 of the organic thin film forming apparatus of the present invention Explanatory drawing 1 showing the structural formula of the organic evaporation material Explanatory drawing showing the structural formula of the organic evaporation material 2 Explanatory drawing 3 showing the structural formula of the organic evaporation material Explanatory drawing showing organic EL elements Diagram showing light absorption and fluorescence emission spectrum of α-NPD Diagram showing light absorption and fluorescence emission spectrum of Alq3 Fluorescence emission intensity vs. film thickness correlation diagram The figure explaining the change of the reflected light intensity and the fluorescence emission intensity during film formation of the doping film Reflectivity and film thickness correlation diagram of Alq3 film (DCM 20.5 wt% dopant) Correlation diagram of DCM2 fluorescence emission intensity and Alq3 film thickness (DCM20.5wt% dopant)

Explanation of symbols

1 Vacuum chamber
2 Board
3 Substrate holder
4 Organic evaporation sources
5 Organic evaporation materials
6 Mask
7 Shutter
8 Y-branch optical fiber
9 Optical fiber
10 optical fiber
11 Y-branch optical fiber tip
12 Light source
13 Light detector
14 Measuring equipment
15 Deposition rate detection means
16 Control unit
17 steam
20 Second light source
21 Second photodetector
22 Optical fiber
23 Optical fiber
24 Optical fiber tip
25 Measuring equipment
26 Control unit
30 Glass substrate
31 Transparent conductive film
32 Hole transport layer
33 Light-emitting layer
34 Electron transport layer
35 Cathode metal
36 cans
37 EL light

Claims (20)

A measuring device for measuring a doping concentration in an organic thin film of a structure,
A light source that projects irradiation light in a wavelength range including at least excitation light to the structure during film formation,
Detecting means for receiving at least fluorescence from the structure with respect to the irradiation light and obtaining fluorescence intensity of the structure;
A measuring apparatus comprising a concentration measuring means for measuring the concentration of a doping material doped in the organic film based on the thickness of the organic thin film and the fluorescence intensity. The measuring device according to claim 1,
A measuring apparatus comprising the concentration measuring means for measuring a doping concentration based on the intensity of the fluorescence with respect to the thickness of the organic thin film. An organic thin film forming apparatus for forming an organic thin film on a structure,
A light source that projects irradiation light in a wavelength range including at least the wavelength of excitation light onto the structure during film formation,
A light detector that receives light from the structure with respect to the irradiation light and performs wavelength separation and light intensity detection; and
Comprising a measuring device connected to the photodetector;
The measuring apparatus includes: first observation means for observing the fluorescence wavelength and fluorescence intensity of the structure from the light wavelength and light intensity output from the photodetector; and the output of the organic thin film from the output of the first observation means. An organic thin film forming apparatus comprising: first measuring means for measuring a thickness; and second measuring means for measuring a doping concentration in the organic thin film from an output of the first observing means. The organic thin film forming apparatus according to claim 3,
The photodetector simultaneously receives fluorescence of the structure with respect to excitation light included in the irradiation light and reflected light or transmitted light with respect to the irradiation light,
The measurement apparatus includes: second observation means for observing the absorption wavelength and absorption intensity of the structure from the light wavelength and light intensity output from the photodetector; and the organic substance from the output of the second observation means. An organic thin film forming apparatus comprising a third measuring means for measuring the thickness of the thin film. The organic thin film forming apparatus according to claim 3,
The first measuring means calculates the thickness of the organic thin film by comparing the output of the first observing means with the first theoretical value of fluorescence characteristics for the film thickness including at least the target film thickness value,
The theoretical value of the first fluorescence characteristic is a value calculated using a dependence characteristic of the light intensity of the excitation light, the fluorescence intensity of the structure, and the thickness of the organic thin film. Thin film forming equipment. The organic thin film forming apparatus according to claim 3,
The second measuring means calculates the doping concentration of the organic thin film by comparing the output of the first observing means with the second or third theoretical fluorescence characteristic value for the doping concentration including at least the target doping concentration. And
The theoretical value of the second fluorescence characteristic is a value calculated by using the dependence of the fluorescence wavelength of the doped doping material and the doping concentration in the organic thin film,
The third theoretical value of the fluorescence characteristic is a value calculated using the dependence characteristics of the fluorescence intensity of the doping material to be doped, the thickness of the organic thin film, and the doping concentration in the organic thin film. An organic thin film forming apparatus. The organic thin film forming apparatus according to claim 6, further comprising:
In the second theoretical value of the fluorescence characteristic, the value is calculated based on the fact that the fluorescence wavelength is shifted to the longer wavelength side as the doping concentration in the organic thin film is increased. apparatus. The organic thin film forming apparatus according to claim 6, further comprising:
In the third theoretical value of fluorescence characteristics, the doping concentration in the organic thin film is a value calculated based on a monotonically increasing fluorescence intensity with respect to the thickness of the organic thin film. Thin film forming equipment. The organic thin film forming apparatus according to claim 4,
The third measuring means compares the output of the second observing means with the first or second absorbed light theoretical value for the film thickness including at least the target film thickness value to determine the film thickness of the organic thin film. Calculate
The theoretical value of the first absorbed light depends on the light intensity of the predetermined wavelength light in the irradiation light, the light intensity of the wavelength light in reflected or transmitted light from the structure, and the thickness of the organic thin film. It is a value calculated using characteristics,
The theoretical value of the second absorbed light is a value calculated using the dependence of the spectral characteristics of the irradiation light, the spectral characteristics of reflected or transmitted light from the structure, and the thickness of the organic thin film. An organic thin film forming apparatus characterized by the above. The organic thin film forming apparatus according to any one of claims 2 to 9,
A second light source for projecting irradiation light in a wavelength range including at least excitation light onto the organic material immediately before being formed in the structure; and
Receiving a light from the organic material, performing wavelength separation and light intensity detection of the received light, and comprising a second photodetector that outputs the result of the wavelength separation and light intensity detection to the measurement device,
The measuring apparatus comprises: third observation means for observing the fluorescence wavelength and fluorescence intensity of the organic material from the wavelength and light intensity output from the second photodetector; and the output of the third observation means. An organic thin film forming apparatus comprising a fourth measuring means for measuring a doping concentration in the organic thin film. The organic thin film forming apparatus according to claim 10,
The fourth measuring means measures the doping concentration of the organic thin film by comparing the output of the third observing means with the fourth or fifth fluorescent characteristic theoretical value for the doping concentration including at least the target doping concentration. And
The theoretical value of the fourth fluorescence characteristic is a value calculated using the dependence specification of the fluorescence wavelength of the doping material in the organic material and the doping concentration of the organic thin film,
The fifth theoretical value of the fluorescence characteristic is a value calculated using the dependence characteristics of the fluorescence intensity of the doping material in the organic material, the thickness of the organic thin film, and the doping concentration of the organic thin film. An organic thin film forming apparatus. An organic thin film forming apparatus according to any one of claims 3 to 11,
An evaporation source for depositing an organic material on the structure, a shutter for shielding the evaporation source from the structure, and a control device connected to the measurement device;
The control device controls the evaporation source so that the thickness or doping concentration of the organic thin film becomes a desired value based on the output from the measuring device, and the time when the organic thin film reaches the desired thickness. And controlling the evaporation source or the shutter so as to terminate the vapor deposition. An organic thin film forming apparatus according to any one of claims 3 to 12,
The light source projects light to the structure through an optical fiber having a light projecting end disposed close to the structure and the other end connected to the light source,
The light detector receives light from the structure through an optical fiber having a light receiving end disposed close to the structure and the other end connected to the light detector. The organic thin film forming apparatus according to claim 13,
The optical fiber is a Y-branched optical fiber having a light projecting / receiving end disposed close to the structure and the other end connected to the light source and the photodetector.
An organic thin film forming apparatus, wherein the light projecting / receiving end of the optical fiber simultaneously performs light projecting on the structure and light receiving from the structure. The organic thin film forming apparatus according to any one of claims 1 to 14,
An organic thin film forming apparatus, wherein the irradiation structure is irradiated with a real structure during film formation. An organic thin film forming method for forming an organic thin film on a structure,
At least during the film formation, the structure is irradiated with excitation light to receive light from the structure,
Perform a first observation to observe the fluorescence wavelength and fluorescence intensity of the light, or perform a second observation to observe the absorption wavelength and absorption light intensity of the structure,
Performing a first measurement to measure the thickness of the organic thin film from the result of the first observation, performing a second measurement to measure the doping concentration of the organic thin film from the result of the first observation, or A method of forming an organic thin film, comprising performing a third measurement for measuring the thickness of the organic thin film from the result of the second observation. The method for forming an organic thin film according to claim 16,
A method of forming an organic thin film, wherein the result of the first, second or third measurement is fed back to evaporation source control of the organic thin film. A method for forming a doping element in an organic thin film functional element,
At least during the film formation, the structure is irradiated with light in a wavelength range including excitation light of the doping material,
Observing the fluorescence of the doping material by the excitation light,
The doping concentration of the organic thin film is measured from the observation result,
Measure the thickness of the organic thin film from the light intensity of the reflected light or transmitted light irradiated to the structure,
A method of forming the organic thin film, wherein the doping concentration and the thickness of the organic thin film are simultaneously measured and controlled. A measuring device for measuring a doping concentration in an organic thin film of a structure,
A light source that projects irradiation light in a wavelength range including at least excitation light to the structure during film formation,
Detection means for receiving at least fluorescence from the structure with respect to the irradiation light and obtaining a fluorescence wavelength of the structure;
A measuring apparatus comprising concentration measuring means for measuring the concentration of a doping material doped in the organic film based on the fluorescence wavelength. The measuring device according to claim 19, wherein
A measuring apparatus comprising measuring a doping concentration based on a shift of the fluorescence wavelength to a longer wavelength side as the doping concentration increases.

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