JP2006349648A - Analysis method of organic material used for organic electroluminescence element, analysis method of composite film and analysis method of multilayer film using spectral ellipsometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and accurately analyze the composition of a film-like organic layer in a non-destructive state. <P>SOLUTION: In step S1, the transmittance spectrum or absorption spectrum of a single-layer film of a sample to be analyzed is measured by a spectrophotometer. In step S2, at least either the composition or structure of the sample is predicted based on the spectrum, and a multi-dimensional function is set. In step S3, ellipso-parameters Δ and Ψ of the sample are measured with a spectral ellipsometer. In step S4, ellipso-parameters Δand Ψof the sample are calculated using the dielectric function, and fitting is performed by regression analysis so that the average square error, between the calculated values of the elipso-parameters Δ and Ψ and the measured values by the spectral ellipsometer, is minimized or lies within an allowable range to estimate an optimum dielectric function. In step S5, a refractive index n and an attenuation coefficient k are determined. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic substance analysis method, a composite film analysis method, and a multilayer film analysis method used for an organic electroluminescence device using a spectroscopic ellipsometer.

  Conventionally, in a method for manufacturing an organic electroluminescence element (hereinafter, electroluminescence may be referred to as EL), there is a method in which a host material and a dopant material are mixed so as to have a predetermined mixing ratio to form a light emitting layer. Proposed. And as a method of calculating | requiring the mixing ratio (dopant density | concentration) of dopant material with respect to host material, using liquid chromatography is disclosed (refer patent document 1).

In addition, an analysis method of an ultrathin film two-layer structure using a spectroscopic ellipsometer has been proposed (see Patent Document 2). In the method of Patent Document 2, first, a very thin two-layer structure on the surface of a substrate to be measured is measured using a spectroscopic ellipsometer, and the polarization of incident light and reflected light for each wavelength λi is changed by changing the wavelength of incident light. The measurement spectra Ψ E (λ i) and Δ E (λ i) are obtained. In the analysis of data obtained using a spectroscopic ellipsometer (hereinafter sometimes referred to as ellipso data), the first step is to select a plurality of models that are likely to fit the actual sample, and to set initial values. decide. When creating a model, the possible complex refractive indices (N1, (n1, k1)), (N2, (n2, k2)) of the materials (Mat1, Mat2) of each thin film, the film thicknesses (d1, Several models are created using d2). As the next second step, an extended best local minimum calculation is performed based on the initial value. Next, as a third step, the results are used to perform final fitting, confirmation, and storage to determine the optical constants (refractive index n and extinction coefficient k) and film thickness of each layer.
JP 2004-134154 A (paragraph [0013] of the specification) JP 2003-302334 A

  In order to determine the amount of dopant in the host material using liquid chromatography, it is necessary to dissolve the film in a solvent, and the film as a sample cannot be measured in a non-destructive state. In addition, it takes time for dissolution, and depending on the material, there is no proper solvent and analysis may be difficult.

  In Patent Document 2, when analyzing ellipso data, as a first stage, a plurality of models that seem to fit well with an actual sample are selected to determine initial values. When the sample is inorganic, there are many known data that can be used as a reference for selecting a plurality of models to be used for analysis. However, in the case of organic materials used in organic electroluminescent devices, there is very little known data available as such a reference.

  Therefore, in the case of an organic substance used for an organic electroluminescence element, it is difficult to create a model by selecting the complex refractive index of the thin film material from known data when analyzing the ellipso data. Therefore, in the analysis of the ellipso data, a dispersion formula that is a formula showing the wavelength dependence of the dielectric constant of a substance is used. However, in the case of organic materials used in organic electroluminescence devices, the molecular structure is complex, the dielectric function is complex with many types of materials, and there are few known data available. It is difficult to set a function, the number of trials and errors increases, and it is difficult to analyze the composition easily. In addition, it is difficult to improve the accuracy of the analysis results.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to analyze an organic substance using a spectroscopic ellipsometer capable of easily and accurately analyzing a film-like organic layer in a non-destructive state. Is to provide.

  In order to achieve the above object, an invention according to claim 1 is a method for analyzing an organic substance used in an organic electroluminescence device using a spectroscopic ellipsometer. And measuring the transmittance spectrum or absorption spectrum of the single layer film of the sample to be analyzed with a spectrophotometer, and predicting at least one of the composition and the structure of the sample based on the spectrum, and a multidimensional dielectric function And a step of measuring the ellipso parameters Δ and ψ of the sample with a spectroscopic ellipsometer. Further, the theoretical values of the ellipso parameters Δ, ψ of the sample are calculated using the dielectric function, and the mean square error between the theoretical values of the ellipso parameters Δ, ψ and the measured values by the spectroscopic ellipsometer is minimum or within an allowable range. So that the optimum estimated dielectric function is obtained by fitting the fitting parameter of the dielectric function by regression analysis. Δ is the phase difference between s-polarized light and p-polarized light, and ψ is the amplitude ratio between s-polarized light and p-polarized light.

  In this invention, a transmittance spectrum or an absorption spectrum of a single layer film of a sample to be analyzed is measured with a spectrophotometer, and at least one of the composition and structure of the sample is predicted based on the spectrum, and a multidimensional dielectric function is obtained. Therefore, the probability that an appropriate dielectric function is set in the analysis of the ellipso data is increased. Fitting is performed by regression analysis so that the mean square error between the theoretical value obtained by calculating the ellipso parameters Δ and ψ of the sample using the set dielectric function and the measured value by the spectroscopic ellipsometer is within the minimum or allowable range. . As a result, an optimally estimated dielectric function is obtained. Further, from this dielectric function, a refractive index n and an extinction coefficient k, which are optical constants specific to the substance, are obtained. Therefore, the film-like organic layer can be analyzed easily and accurately in a non-destructive state.

  The invention according to claim 2 is an analysis method using a spectroscopic ellipsometer of a composite film in which a plurality of organic substances are present in a single layer film. In addition, a single layer film is created independently for each constituent material of the composite film, and an optimum estimated dielectric function is obtained by the method of claim 1, and the composition ratio of the plurality of organic substances is determined using the optimum estimated dielectric function. By fitting the composite film using the effective medium approximation as a fitting parameter, an estimated value of the composition ratio of the composite film and an optimal estimated dielectric function of the composite film are obtained. In the present invention, a single proper dielectric function is obtained for each of a plurality of types of organic substances constituting the composite film, and the entire composition is analyzed based on the obtained dielectric functions, so that the dielectric function corresponding to the mixed organic substance from the beginning. The composite membrane can be analyzed easily and accurately as compared with the case of setting.

According to a third aspect of the invention, in the invention of the second aspect, the composite film is made of an organic material comprising a host and a dopant.
The invention according to claim 4 is an analysis method using a multilayer film ellipsometer in which a plurality of single-layer films are stacked, and each single-layer film is analyzed by the method according to claim 1 or claim 2. An optimum estimated dielectric function is obtained, and an estimated value of the stacking order and film thickness is obtained by fitting the measured value by the spectroscopic ellipsometer with the stacking order and film thickness of each single layer film as a fitting parameter. In the present invention, even a multilayer film can be analyzed easily and accurately in a non-destructive state. In this invention, for example, the stacking order and film thickness of the hole transport layer, the light emitting layer, the electron transport layer, etc. of the organic EL element can be analyzed in a non-destructive state. Each layer may be a layer (composite film) made of a host and a dopant, a layer made of a single material, or a layer in which both are mixed.

  According to the present invention, a film-like organic layer can be easily and accurately analyzed in a non-destructive state.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
First, the case where the sample to be analyzed is a single layer film composed of one kind of organic substance will be described with reference to the flowchart of FIG.

In step S1, the transmittance spectrum or absorption spectrum of the single layer film of the sample to be analyzed is measured with a spectrophotometer. The measurement is performed in the wavelength range of 250 to 1000 nm.
Next, in step S2, at least one of the composition and structure of the sample is predicted based on the spectrum data obtained in step S1, and a multidimensional dielectric function is set. A Gaussian oscillator type dielectric function is used as the dielectric function.

The dielectric function and fitting parameters of the Gaussian oscillator type are expressed by the following equations.
ε _n = ε _n1 + iε _n2
ε _n2 = Amp _n · exp {− (E−En _n ) / Br _n } + Amp _n · exp {− (E + En _n ) / Br _n }

ε_ｎ１はKramers-Kronig（Ｋ−Ｋ）の関係を満足する。

ε _n1 satisfies the Kramers-Kronig (KK) relationship.

Amp _n : amplitude of the n th vibrator, En _n : center energy of the n th vibrator Br _n : spread of the n th vibrator Next, in step S3, the single layer film of the sample to be analyzed by the spectroscopic ellipsometer Measure the ellipso parameters Δ, ψ. Δ is a phase difference between s-polarized light and p-polarized light, and ψ is an amplitude ratio between s-polarized light and p-polarized light.

  Next, in step S4, fitting by the regression analysis method between the theoretical values and measured values of the ellipso parameters Δ and ψ of the sample is performed. As the regression analysis method, for example, a regression analysis method based on the Levenberg-Marquardt method is used. “Fitting” means matching unknown values (layer thickness, dielectric function parameters, etc.) included in the model to the measured value. The operation in step S4 is performed by a computer.

  More specifically, the ellipso parameters Δ, ψ of the sample are calculated using the dielectric function fitting parameters set in step S2. Then, fitting is performed by the regression analysis method so that the mean squared error (MSE) between the calculated value and the value measured by the spectroscopic ellipsometer obtained in step S3 is within an allowable range. That is, it is determined whether the mean square error between the theoretical value and the measured value of the ellipso parameters Δ and ψ theoretically obtained from the set dielectric function is minimum or within an allowable range, and the mean square error is minimum or allowable. If it is not within the range, the dielectric function parameters are changed, the theoretical values of the ellipso parameters Δ and ψ are calculated, and the mean square error from the measured values is calculated. When the fitting is repeated and the mean square error is minimum or within an allowable range, an optimally estimated dielectric function is obtained, and the process proceeds to step S5. For example, the fitting is repeated until the mean square error becomes 20 or less.

In step S5, the refractive index n and the extinction coefficient k are obtained from the optimum estimated dielectric function. The refractive index n and the extinction coefficient k are optical constants specific to the material.
Next, the case where the sample to be analyzed is a composite film in which a plurality of organic substances are present in a single layer film will be described. When the sample to be analyzed is a composite film, a single-layer film sample is created independently for each constituent material of the composite film. Then, by performing the operations of Step S1 to Step S4 for each sample, a single optimally estimated dielectric function is obtained for each of a plurality of types of organic substances constituting the composite film.

  Next, the dielectric function of the composite film is calculated using the effective medium approximation, with the composition ratio of each organic material constituting the composite film as a fitting parameter. For the effective medium approximation, for example, Bruggeman's Effective Medium Approximation is used.

In addition, the ellipso parameters Δ and ψ of the composite film of the sample to be analyzed by the spectroscopic ellipsometer are measured.
Next, theoretical values of the ellipso parameters Δ and ψ of the composite film are calculated using the dielectric function of the composite film. Then, the fitting is performed by the regression analysis method so that the mean square error between the theoretical value and the measured value by the spectroscopic ellipsometer is within the minimum or allowable range. When the mean square error is minimum or within an allowable range, the composition ratio of each organic material constituting the composite film and the optimum estimated dielectric function of the composite film are obtained.

  Next, a case where the sample to be analyzed is a multilayer film in which a plurality of single-layer films are stacked will be described. When the sample to be analyzed is a multilayer film, the dielectric function of each single layer film is obtained for each single layer film by the method described above. Further, the ellipso parameters Δ and ψ of the multilayer film of the sample to be analyzed by the spectroscopic ellipsometer are measured. Then, using the stacking order and film thickness of each single-layer film as fitting parameters, the dielectric function of each single-layer film, the theoretical values of the ellipso parameters Δ and ψ calculated using the stacking order and film thickness of each single-layer film, and Fitting with the measured value by the spectroscopic ellipsometer. When the mean square error between the theoretical value and the value measured by the spectroscopic ellipsometer is minimum or within an allowable range, an estimated value of the stacking order and film thickness is obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples in which an organic electroluminescent material as an organic material used as a material for an organic EL hole transport layer, a light emitting layer, and an electron transport layer is used as a sample. However, these are merely examples and do not limit the present invention. In each embodiment, as a spectroscopic ellipsometer, J.A. A. M-2000U manufactured by Woollam was used.

<Example 1>
A glass substrate having a thickness of 0.5 mm is prepared, washed, and then a trilayer (8-hydroxyquinoline) aluminum (Alq3) is vapor-deposited on the glass substrate by a vacuum vapor deposition apparatus. It was created. Three types of fitting parameters Amp _n , En _n and Br _n in the Gaussian oscillator type dielectric function of the sample were set as follows.

Amp1 0.784
En1 3.100
Br1 0.428
Amp2 1.719
En2 5.769
Br2 3.314
Amp3 3.741
En3 4.585
Br3 0.313
In addition, the said fitting parameter rounded off the 4th decimal point and showed the value to the 3rd decimal point.

  Ellipso parameters Δ and ψ were measured with a spectroscopic ellipsometer for the single-layer film sample. The measurement was performed by setting the incident angles to 60 °, 65 °, and 70 ° and the wavelength λ in the range of 250 to 1000 nm.

  Then, fitting was performed between the theoretical values of the ellipso parameters Δ and ψ calculated from the dielectric function and the measured values by the spectroscopic ellipsometer. As a result, MSE = 3.6.

  The results are shown in FIGS. 2 to 4 show the chromatic dispersion characteristics, and FIG. 2 is a graph showing the relationship between the transmittance and the wavelength (in FIG. 2, Exp in FIG. 2 indicates the transmittance spectrum with the incident angle set to 90 degrees). 3 is a graph showing the relationship between Δ and wavelength, FIG. 4 is a graph showing the relationship between ψ and wavelength, and FIG. 5 is an optical constant of refractive index n, extinction coefficient k and wavelength. It is a graph which shows the relationship. 2 to 4, it is confirmed that the fitting was performed well and the dielectric function was estimated with high accuracy.

<Example 2>
A glass substrate having a thickness of 0.5 mm was prepared, washed, and then quinacridone was deposited on the glass substrate by a vacuum deposition apparatus to prepare a single layer film sample having a thickness of 23.8 nm. Six types of fitting parameters Amp _n , En _n and Br _n in the Gaussian oscillator type dielectric function of the sample were set as follows.

Amp1 2.355
En1 2.189
Br1 0.162
Amp2 0.931
En2 2.360
Br2 0.107
Amp3 1.063
En3 2.395
Br3 0.446
Amp4 0.099
Br4 0.154
En5 3.685
Amp5 1.458
En5 4.375
Br5 0.518
Amp6 2.795
En6 5.635
Br6 2.246
In addition, the said fitting parameter rounded off the 4th decimal point and showed the value to the 3rd decimal point.

  Ellipso parameters Δ and ψ were measured with a spectroscopic ellipsometer for the single-layer film sample. The measurement was performed by setting the incident angles to 60 °, 65 °, and 70 ° and the wavelength λ in the range of 250 to 1000 nm.

  Then, fitting was performed between the theoretical values of the ellipso parameters Δ and ψ calculated from the dielectric function and the measured values by the spectroscopic ellipsometer. As a result, MSE = 14.7.

  The results are shown in FIGS. 6 to 8 show chromatic dispersion characteristics, and FIG. 6 is a graph showing the relationship between the transmittance and the wavelength (Exp in FIG. 6 is an incident angle set to 90 degrees and the transmittance spectrum is measured. 7 is a graph showing the relationship between Δ and wavelength, FIG. 8 is a graph showing the relationship between ψ and wavelength, and FIG. 9 is a relationship between refractive index n and extinction coefficient k, which are optical constants, and wavelength. It is a graph which shows. It can be confirmed from FIGS. 6 to 8 that the fitting was performed well and the dielectric function was estimated with high accuracy.

<Example 3>
A glass substrate having a thickness of 0.5 mm is prepared, and after washing, 4-dicyanomethylene-2-methyl-6- (4-dimethylaminostyryl) -4H-pyran (DCM1) is deposited on the glass substrate by a vacuum deposition apparatus. A single layer film sample having a thickness of 25.9 nm was prepared by vapor deposition. Six types of fitting parameters Amp _n , En _n and Br _n in the Gaussian oscillator type dielectric function of the sample were set as follows.

Amp1 1.257
En1 2.291
Br1 0.213
Amp2 2.152
En2 2.470
Br2 0.342
Amp3 2.509
En3 2.668
Br3 0.487
Amp4 1.106
En4 3.122
Br4 0.831
Amp5 3.558
En5 9.957
Br5 5.450
Amp6 0.931
En6 4.143
Br6 1.170
In addition, the said fitting parameter rounded off the 4th decimal point and showed the value to the 3rd decimal point.

  Ellipso parameters Δ and ψ were measured with a spectroscopic ellipsometer for the single-layer film sample. The measurement was performed by setting the incident angles to 60 °, 65 °, and 70 ° and the wavelength λ in the range of 250 to 1000 nm.

  Then, fitting was performed between the theoretical values of the ellipso parameters Δ and ψ calculated from the dielectric function and the measured values by the spectroscopic ellipsometer. As a result, MSE = 6.7.

  The results are shown in FIGS. 10 to 12 show the chromatic dispersion characteristics, and FIG. 10 is a graph showing the relationship between the transmittance and the wavelength (in FIG. 10, Exp in the figure means that the incident angle is set to 90 degrees and the transmittance spectrum is FIG. 11 is a graph showing the relationship between Δ and wavelength, FIG. 12 is a graph showing the relationship between ψ and wavelength, and FIG. 13 is an optical constant of refractive index n, extinction coefficient k and wavelength. It is a graph which shows a relationship. From FIG. 10 to FIG. 12, it is confirmed that the fitting was performed well and the dielectric function was accurately estimated.

<Example 4>
Next, an example will be described in which the sample to be analyzed is a composite film in which a plurality of organic substances are present in a single layer film.

Prepare a glass substrate with a thickness of 0.5 mm, and after cleaning, use a vacuum evaporation system on the glass substrate.
A composite film sample having a film thickness of 16.2 nm was prepared using Alq3 as a host and quinacridone as a dopant. Quinacridone was prepared so as to be 5 wt% with respect to Alq3.

  Ellipso parameters Δ and ψ were measured with a spectroscopic ellipsometer for the composite film sample. The measurement was performed by setting the incident angles to 60 °, 65 °, and 70 ° and the wavelength λ in the range of 250 to 1000 nm.

  Then, the Ellipso parameter Δ, calculated using the effective medium approximation of Braggman from the dielectric function of Alq3 and quinacridone estimated in Examples 1 and 2 and the volume fraction (composition ratio) of these two substances which are fitting parameters. Fitting was performed between the theoretical value of ψ and the value measured with a spectroscopic ellipsometer. As a result, the MSE was 10.59.

  The results are shown in FIGS. 14 to 16 show the chromatic dispersion characteristics, and FIG. 14 is a graph showing the relationship between the transmittance and the wavelength (in FIG. 14, Exp in the figure means that the incident angle is set to 90 degrees and the transmittance spectrum is shown). FIG. 15 is a graph showing the relationship between Δ and wavelength, FIG. 16 is a graph showing the relationship between ψ and wavelength, and FIG. 17 is an optical constant of refractive index n, extinction coefficient k and wavelength. It is a graph which shows a relationship. 14 to 16, it is confirmed that the fitting was performed well and the composition ratio of the two substances and the dielectric function of the composite film were accurately estimated.

<Example 5>
Next, an example in which the dependence of the complex refractive index wavelength dispersion on the charged amount in a composite film using Alq3 as a host and quinacridone as a dopant is examined will be described.

  Four samples were prepared by changing the amount of quinacridone charged, that is, the concentration of quinacridone relative to Alq3 as a host, as shown in Table 1, and the dope concentration (composition ratio) of quinacridone was determined in the same manner as in Example 4. .

  The results are shown in FIG.

表１からキナクリドンのドープ濃度（組成比）が精度よく求められていることを確認できた。

From Table 1, it was confirmed that the dope concentration (composition ratio) of quinacridone was obtained with high accuracy.

<Example 6>
Next, an example in which the sample to be analyzed is a multilayer film in which a plurality of single-layer films are stacked will be described.

  As an example when the organic EL layer has a three-layer structure of a hole transport layer, a light emitting layer, and an electron transport layer, TPTE layer constituting the hole transport layer, Alq3 constituting the light emitting layer as a host, and quinacridone as a dopant A multilayer film sample having a three-layer structure of an quinacridone / Alq3 layer and an Alq3 layer constituting an electron transport layer was prepared. And the lamination | stacking order of each layer, the film thickness, and the dope density | concentration of quinacridone in quinacridone / Alq3 were calculated | required.

  First, the dielectric functions of TPTE, Alq3, and quinacridone were estimated by the same procedure as in Examples 1 to 3. Next, theoretical values of the ellipso parameters Δ and ψ were calculated from the obtained dielectric function, stacking order, composition ratio of Alq3 and quinacridone, and film thickness of each layer. Here, the stacking order, the composition ratio of Alq3 and quinacridone, and the film thickness of each layer are the fitting parameters. And the fitting of the theoretical value of the ellipso parameter and the measured value was performed.

  Table 2 shows the charged amount and the value of the analysis value obtained by fitting with the ellipso parameters Δ and ψ. In Table 2, the stacking order from the anode is shown in order from the top.

表２から、試料が多層膜であっても、積層順、キナクリドンのドープ濃度（組成比）及び各層の膜厚が比較的精度よく求められていることを確認できた。

From Table 2, it was confirmed that even when the sample was a multilayer film, the stacking order, the quinacridone dope concentration (composition ratio), and the film thickness of each layer were obtained with relatively high accuracy.

This embodiment has the following effects.
(1) Measure the transmittance spectrum or absorption spectrum of the single layer film of the sample to be analyzed with a spectrophotometer, and predict at least one of the composition and structure of the sample based on the spectrum to set a multidimensional dielectric function To do. When analyzing the ellipso data measured by the spectroscopic ellipsometer, the mean square error between the calculated values of the ellipso parameters Δ and ψ calculated using the dielectric function and the measured value by the spectroscopic ellipsometer is within a minimum or allowable range. The fitting is performed by the regression analysis method. As a result, an optimally estimated dielectric function is obtained. Therefore, it is possible to easily and accurately analyze a film-like organic layer, which has been difficult to analyze by a conventional analysis method (liquid chromatography), in a non-destructive state.

  (2) When analyzing a composite film having a plurality of organic substances in the single layer film, a single layer film is created independently for each constituent material of the composite film, and the material for each single layer film is A dielectric function is obtained, and the dielectric film is used and fitting to the composite film is performed using the effective medium approximation. Therefore, the composite film can be analyzed easily and accurately compared to the case where the dielectric function corresponding to the mixed organic substance is set from the beginning.

(3) The composition can be analyzed in a non-destructive state even when the composite film is an organic EL material composed of a host and a dopant, and is a thin film having a thickness of about 10 to 30 nm.
(4) When analyzing a multilayer film sample in which a plurality of single-layer films are stacked, the dielectric function is obtained for each single-layer film by the method described above, and the spectral order is changed by changing the stacking order and film thickness of each single-layer film. Fitting with the measured value by ellipsometer. Therefore, even a multilayer film can be easily analyzed in a non-destructive state. Since the organic EL element generally has a multilayer structure including a hole transport layer, a light emitting layer, and an electron transport layer, the composition of the organic EL material of the organic EL element can be analyzed in a non-destructive state.

The embodiment is not limited to the above, and may be configured as follows, for example.
○ A function other than the Gaussian oscillator type dielectric function may be used as the dielectric function. For example, a Tauc-Lorentz oscillator type dielectric function may be used.

○ Effective medium approximation methods other than Braggman effective medium approximation may be used.
○ Regression analysis based on the Levenberg-Marquardt method is a regression analysis method that performs fitting so that the mean square error between the calculated values of the ellipso parameters Δ and ψ of the sample and the values measured by the spectroscopic ellipsometer is within the minimum or allowable range. Not limited to law.

The following technical idea (invention) can be understood from the embodiment.
(1) In the invention according to any one of claims 1 to 4, the dielectric function is a Gaussian oscillator type dielectric function.

The flowchart which shows the procedure of the analysis method of a sample. 3 is a graph showing the relationship between the transmittance and wavelength in Example 1. The graph which similarly shows the relationship between (DELTA) and a wavelength. The graph which similarly shows the relationship between (psi) and a wavelength. The graph which shows the relationship between the refractive index n and the extinction coefficient k which are optical constants similarly, and a wavelength. 6 is a graph showing the relationship between the transmittance and wavelength in Example 2. The graph which similarly shows the relationship between (DELTA) and a wavelength. The graph which similarly shows the relationship between (psi) and a wavelength. The graph which shows the relationship between the refractive index n and the extinction coefficient k which are optical constants similarly, and a wavelength. 10 is a graph showing the relationship between transmittance and wavelength in Example 3. The graph which similarly shows the relationship between (DELTA) and a wavelength. The graph which similarly shows the relationship between (psi) and a wavelength. The graph which shows the relationship between the refractive index n and the extinction coefficient k which are optical constants similarly, and a wavelength. 10 is a graph showing the relationship between transmittance and wavelength in Example 4. The graph which similarly shows the relationship between (DELTA) and a wavelength. The graph which similarly shows the relationship between (psi) and a wavelength. The graph which shows the relationship between the refractive index n and the extinction coefficient k which are optical constants similarly, and a wavelength. The graph which shows the relationship between the refractive index n of each sample of Example 5, the extinction coefficient k, and a wavelength.

Explanation of symbols

  S1, S2, S3, S4, S5... Step.

Claims (4)

  A method for analyzing an organic substance used in an organic electroluminescence device using a spectroscopic ellipsometer, comprising: measuring a transmittance spectrum or absorption spectrum of a single layer film of a sample to be analyzed with a spectrophotometer; and based on the spectrum Predicting at least one of the composition and structure of the sample and setting a multidimensional dielectric function; measuring the ellipso parameters Δ and ψ of the sample with a spectroscopic ellipsometer; and using the dielectric function, the ellipso of the sample The theoretical values of the parameters Δ and ψ are calculated, and the dielectric function is calculated by the regression analysis method so that the mean square error between the theoretical values of the ellipso parameters Δ and ψ and the measured value by the spectroscopic ellipsometer is at a minimum or within an allowable range. To obtain an optimal estimated dielectric function by fitting the fitting parameters of Example was the analysis method of the organic substance used in the organic electroluminescence device using the spectroscopic ellipsometer.   An analysis method using a spectroscopic ellipsometer of a composite film in which a plurality of organic substances are present in a single layer film, wherein a single layer film is independently created for each constituent material of the composite film and optimized by the method of claim 1 Obtaining an estimated dielectric function, using the optimum estimated dielectric function, and performing fitting on the composite film using effective medium approximation with the composition ratio of the plurality of organic substances as a fitting parameter, and the estimated value of the composition ratio and A method for analyzing a composite film using a spectroscopic ellipsometer to obtain an optimum estimated dielectric function of the composite film.   The method for analyzing a composite film using a spectroscopic ellipsometer according to claim 2, wherein the composite film is made of an organic material comprising a host and a dopant.   An analysis method using a spectroscopic ellipsometer of a multilayer film in which a plurality of single-layer films are stacked, and for each single-layer film, an optimum estimated dielectric function of the single-layer film is obtained by the method of claim 1 or 2, and A multilayer film analysis method using a spectroscopic ellipsometer that obtains an estimated value of the stacking order and film thickness by performing fitting with the measurement value by the spectroscopic ellipsometer using the stacking order and film thickness of the layer film as a fitting parameter.

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