JP4336676B2 - Sample analysis method and sample analysis apparatus - Google Patents

Description

  In the present invention, a film laminated on a substrate is covered with a cover member, and a sample having a structure in which a space (gap) exists between the film layer and the cover member is measured with a measuring instrument such as a polarimeter and an ellipsometer to determine the characteristics of the film. In the case of analysis, the present invention relates to a sample analysis method and a sample analysis apparatus capable of performing a stable analysis without being influenced by the influence of a gap existing in a sample and the reflection form of light in the sample.

  Conventionally, in order to analyze the characteristics (film refractive index, extinction coefficient, film thickness, etc.) of a sample having a film, a measuring instrument that performs measurement by irradiating polarized light such as a polarimeter and an ellipsometer is used. There is. For example, in an ellipsometer, polarized light is incident on a sample, and changes in the polarization state of incident light and reflected light are measured. As shown in FIG. 14A, an amplitude ratio (Ψ psi) and a phase difference (Δ Delta). In addition, the film refractive index (n), extinction coefficient (k), and film thickness (d) cannot be obtained only by the amplitude ratio and phase difference obtained by the ellipsometer, so that the user Build a model according to the sample structure based on the assumptions (analyzer type, film thickness, etc.) for the sample item to be analyzed that are input from, and analyze the sample using the model and ellipsometer measurement results. Do.

  The specific analysis procedure is as follows. First, the amplitude ratio and phase difference obtained by theoretical calculation from the model are compared with the amplitude ratio and phase difference obtained by ellipsometer measurement, and the degree of difference between the two is minimized. A process of changing the parameters of the dispersion formula and the film thickness of the model is performed (referred to as fitting). The difference between the two is usually obtained by calculation using the least square method, and if it is determined that the result obtained by the least square method has been reduced to some extent by fitting, the value of the parameter of the dispersion equation at that time The refractive index and extinction coefficient are determined, and the film thickness at that time is selected as the film thickness of the sample.

In general, creation of a model, calculation by least square method, fitting, and the like are performed manually or automatically based on a required program using a computer (see Patent Documents 1 and 2).
JP 2002-340789 A JP 2002-340528 A

  In the analysis using the above-described ellipsometer, there are various types of samples to be analyzed, and recently there has been a demand for analyzing samples having a film that is not exposed to the outside. For example, for the research and development of organic light emitting diode (OLED) elements, which are attracting attention as next-generation display materials, and for product inspection, etc., an analysis method using the above-described ellipsometer for the organic film of organic EL elements It is expected to be analyzed. In particular, if the prototype organic EL element or the manufactured organic EL element has a structure as designed, or if it does not meet the design, it is desired to be able to confirm which point was bad. In addition, it is desired to be able to confirm how the organic EL element changes (deteriorates) over time.

  However, the organic EL element has an internal structure in which an anode, a plurality of films (organic films), and a cathode are laminated on a transparent substrate such as a glass substrate, and the film is covered with a sealing cap, and the inside is vacuum sealed or sealed. It is very difficult to measure the optical properties of the film with an ellipsometer by irradiating light toward the sealed laminated film and acquiring the reflected light appropriately. There is a problem that it becomes difficult. For this reason, there is a problem that the completed organic EL element has a structure as designed, which point is bad, and further a change with time cannot be properly confirmed at present.

  Even if light can be irradiated to the laminated film disposed in the sealing cap, the sealing cap has a space (gap) between the film and the interference due to light irradiation depending on the gap size. When a fringe occurs and an interference fringe occurs, it takes a very long time to measure, and the values of the amplitude ratio (Ψ) and the phase difference (Δ) obtained based on the model are as shown in FIG. However, there is a problem that fine analysis cannot be performed by finely oscillating vertically.

  Furthermore, due to the structure of the organic EL element, a plurality of reflection modes of light irradiated toward the film of the organic EL element are assumed. Therefore, a plurality of types of models to be used for analysis are prepared in advance and reflection is performed. There is a problem that accurate analysis cannot be performed unless a model corresponding to the form is appropriately selected.

  For example, assuming a situation where light can be irradiated from the glass substrate side of the organic EL element toward the film, when the irradiated light is reflected at the boundary between the film and the gap, the inner surface of the sealing cap passes through the gap. Multiple reflection modes can occur, such as when reflecting off the screen. However, in such a case, the reflected light from the sample actually acquired by the ellipsometer cannot generally be identified as any of the above-described reflection forms. Cannot be selected. Therefore, in actual analysis, it is necessary to perform an enormous amount of calculations using all types of models so that all reflection forms can be considered, and it is necessary to select the best calculation result as the analysis result. Even if the EL element can be measured, there is a problem that the burden of the analysis process is large and it takes a long time to obtain the analysis result. In addition to the organic EL element, each problem as described above also occurs when a sample having a structure equivalent to the organic EL element is analyzed. In addition, even when a polarimeter is used as a measuring instrument, the above-described problems similarly occur.

The present invention has been made in view of such a problem, and it is possible to reliably irradiate a film and acquire reflected light even for a sample having a film inside such as an organic EL element. Another object of the present invention is to provide a sample analysis method and a sample analysis apparatus that can analyze the characteristics of a film that is not exposed to the outside.
Another object of the present invention is to provide a sample analysis method and a sample analysis apparatus that can perform good analysis by eliminating the influence of interference fringes.
It is another object of the present invention to provide a sample analysis method and a sample analysis apparatus that select a model type used for analysis in accordance with the thickness dimension of the sample to improve the efficiency of processing related to the analysis. .

In order to solve the above-described problems, the sample analysis method according to the first aspect of the invention irradiates the optical characteristics of a sample in which a plurality of films laminated on a light-transmitting substrate are covered with a cover member at an interval, and applies polarized light. A sample analysis method for analyzing characteristics of each film layer of a sample based on a model corresponding to the sample and a measurement result of the measurement device, the one surface of the translucent substrate and the cover member The step of placing the sample bonded to one surface of the cover member so that the outer surface of the cover member is in contact with the stage, the step of irradiating the sample with the light that has been polarized, and the light reflected by the sample are obtained. And measuring the polarization state of the acquired light.

  In the sample analysis method according to the second invention, a first model in which a void layer and a film layer overlap and a second model in which a layer, a void layer, and a film layer according to a cover member overlap are prepared, The method includes a step of receiving a thickness dimension of a sample to be measured, and a step of selecting the first model and / or the second model as a model to be used for analysis according to the received thickness dimension.

  The sample analysis method according to the third invention includes a first model in which the void layer and the film layer overlap, a second model in which the layer related to the cover member, the void layer, and the film layer overlap, a layer related to the ambient atmosphere of the cover member, A third model in which a layer related to the cover member, a void layer, and a film layer are overlapped, a step of accepting a thickness dimension of the sample measured by the measuring instrument, and a sample measured by the measuring instrument is translucent Selecting at least one of the first model, the second model, and the third model as a model to be used for analysis according to the received thickness dimension. To do.

In the sample analysis method according to the fourth aspect of the present invention, the optical characteristics of a sample in which a plurality of films laminated on a substrate are covered with a cover member at an interval are measured with a measuring instrument that emits polarized light, and the sample is analyzed. model and based on a measurement result of the measuring device a sample analyzing method for analyzing the properties of each layer of the sample, the translucent in one surface of said cover member and a surface of the translucent substrate is bonded samples Placing on the stage with the conductive substrate facing down, irradiating the sample cover member with polarized light, obtaining the light reflected from the sample, and measuring the polarization state of the obtained light And a step.

  The sample analysis method according to the fifth aspect of the invention creates a first model in which a layer and a film layer related to a substrate overlap, and a second model in which a layer related to the ambient atmosphere of the substrate, a layer related to the substrate, and a film layer overlap. And receiving the thickness dimension of the sample to be measured by the measuring instrument, and when the sample to be measured by the measuring instrument has a light-transmitting substrate, the first model and / or the first model is selected according to the received thickness dimension. Selecting two models as models to be used for analysis.

  In the sample analysis method according to the sixth aspect of the invention, when a plurality of models to be used for analysis are selected, fitting is performed for each model to calculate a mean square error, and a minimum mean square error is selected from the plurality of models. A model selection step of selecting a model related to the value, or a model having a minimum mean square error value falling within a range from a minimum value to a maximum value of a preset film thickness, and selected in the model selection step A value relating to the model is used as an analysis result.

A sample analysis method according to a seventh aspect of the invention includes a step of calculating an item equivalent to an item to be measured by the measuring device based on a model used for analysis, and in this step, interference generated in the sample by light irradiation. One of the first calculation processing corresponding to the fringes or the second calculation processing not corresponding to the interference fringes is performed, and the characteristics of the film are analyzed using the calculated results.
The sample analysis method according to an eighth aspect of the present invention includes a step of comparing the distance between the sample film and the cover member and the reference distance, and when the distance is larger than the reference distance, the second calculation process is performed. Features.
A sample analysis method according to a ninth aspect includes a step of changing the value of the reference distance.

According to a tenth aspect of the present invention, there is provided a sample analyzing apparatus that obtains light reflected by a sample by irradiating means for irradiating polarized light onto a sample having a film laminated on a light-transmitting substrate and covered with a cover member. A sample analyzer comprising a measuring device having means for measuring a polarization state, and a model corresponding to the sample and means for analyzing the characteristics of the sample based on the measurement results of the measuring device, and a plurality of different structures And a thickness dimension that is the sum of the thickness of the translucent substrate and the thickness of the cover member of the sample in which one surface of the translucent substrate and one surface of the cover member are bonded together is received. and means, in response to the thickness accepted, characterized in that it comprises means for selecting a model used in the analysis from the plurality of models.

According to an eleventh aspect of the present invention, there is provided a sample analyzing apparatus that obtains light reflected by a sample by irradiating means for irradiating polarized light onto a sample that covers a film laminated on a translucent substrate with a cover member at an interval. A sample analyzer comprising a measuring instrument having a means for measuring the polarization state, a model corresponding to the sample, and an analyzing means for analyzing the characteristics of the sample based on the measurement result of the measuring instrument, the model being used for the analysis Based on the first measurement processing corresponding to the interference fringes generated in the sample by light irradiation, or the interference fringes. Any one of the non-corresponding second calculation processes is performed, and the analysis means analyzes the characteristics of the film using the result calculated by the calculation means, and the one surface of the translucent substrate and the cover member are analyzed . One side was pasted together Performing charge film and means for receiving the spacing distance to the cover member from, and means for comparing the spacing distance and the reference distance is accepted, if the gap distance is greater than the reference distance, the calculating means said second arithmetic processing It is characterized by that.

In the sample analysis method according to the present invention, the optical characteristics of a sample in which a plurality of films laminated on a light-transmitting substrate are covered with a cover member at an interval are measured with a measuring instrument that irradiates polarized light. A sample analysis method for analyzing the characteristics of each film layer of a sample based on a corresponding model and the measurement result of the measuring device, the step of irradiating polarized light to the light-transmitting substrate of the sample, and the sample reflected by the sample A step of acquiring light, a step of measuring a polarization state of the acquired light, a first model in which the gap layer and the film layer overlap, and a second model in which the layer, the gap layer, and the film layer according to the cover member overlap. A step of preparing, a step of receiving a thickness dimension of a sample to be measured by the measuring instrument, and a step of selecting the first model and / or the second model as a model to be used for analysis according to the received thickness dimension; Characterized in that it comprises. In the sample analysis method according to the present invention, the optical characteristics of a sample in which a plurality of films laminated on a substrate are covered with a cover member at an interval are measured with a measuring instrument that emits polarized light, and a model corresponding to the sample is measured. And a sample analysis method for analyzing characteristics of each film layer of the sample based on the measurement result of the measuring device, the step of irradiating the sample cover member with polarized light, and the step of acquiring the light reflected by the sample Measuring a polarization state of the acquired light; a first model in which a layer and a film layer related to the substrate overlap; a layer related to an ambient atmosphere of the substrate; a layer related to the substrate; and a second model in which the film layer overlaps. A step of accepting a thickness dimension of a sample to be measured by the measuring instrument, and a sample to be measured by the measuring instrument having a light-transmitting substrate, the first dimension is determined according to the accepted thickness dimension. 1 model Characterized in that it comprises the steps of selecting a model used to analyze the beauty / or the second model.

  In the first invention, since light is irradiated toward the translucent substrate of the sample, the light passed through the translucent substrate can be reliably applied to the laminated film, and the film of the film can be measured with a measuring instrument. Optical characteristics can be measured. For this reason, it is possible to confirm whether or not the sample such as the completed organic EL element has a structure as designed, what kind of point is bad in manufacturing, and whether a change with time has occurred. In addition, in order to irradiate light toward the translucent substrate of the sample, the sample is placed on the stage of the measuring instrument so that the translucent substrate is on the upper side, or the translucent stage is provided with a hole. It is conceivable that the sample is placed so that the substrate is on the lower side, and light is irradiated toward the translucent substrate through the hole of the stage. Moreover, an ellipsometer, a polarimeter, etc. are applicable to a measuring device.

  In the second invention, since one or both of the first model and the second model prepared in advance are included in the model used for the analysis in accordance with the thickness dimension of the sample to be measured. Efficient analysis processing can be performed without using a model that deviates from the actual reflection form. That is, the inventor of the present invention pays attention to the fact that the reflection form related to the light that can be acquired by the measuring instrument is limited to some extent according to the overall thickness of the sample, and accepts it as a setting target necessary for performing the analysis. At least one of the first model and the second model is included as a model corresponding to the reflection form that can be assumed from the thickness dimension of the target sample. As a result, the number of models required for the analysis can be narrowed down and the calculation can be performed, so that the analysis process can be made more efficient.

  In the third invention, even when the cover member of the sample has translucency, the reflection form related to the light that can be obtained by the measuring instrument is limited according to the overall thickness of the sample. An efficient analysis process can be realized by including at least one of the first model to the third model as the corresponding model and performing the analysis.

  In the fourth invention, when the cover member covering the sample film is translucent, the light that has passed through the cover member is applied to the internal film by irradiating the cover member with light. The optical properties of the film can be measured with a measuring instrument such as an ellipsometer. Thereby, it becomes possible to confirm whether the sample has a structure as designed with respect to a sample such as an organic EL element, what kind of point is bad in manufacturing, whether a change with time has occurred, or the like. In addition, when irradiating light to a cover member, since a sample can be mounted so that a board | substrate may become a lower side on the stage of a measuring device, the mounting form of a sample is also stabilized.

  In the fifth invention, when the substrate of the sample has translucency, the reflection form related to the light that can be acquired by the measuring instrument also depends on the overall thickness of the sample even when irradiating the light toward the cover member. Therefore, it is possible to perform analysis by including at least one of the first model and the second model as a model corresponding to the limited reflection form, and to efficiently perform analysis processing related to the model.

  In the sixth invention, when a plurality of models to be used for the analysis are selected, fitting is performed on all of the models to calculate a mean square error according to the least square method, and the mean square error is the lowest. Or a value related to a model having the lowest mean square error among structurally valid models is used as the analysis result. Therefore, even if a plurality of models are used, an optimal analysis result can be obtained.

  In the seventh invention, when a model corresponding to a sample in which interference fringes are generated by light irradiation is used, the amplitude ratio (Ψ) and the phase difference (Δ) obtained by calculation from the model are vertically amplified. In such a case, an analysis result according to the user's needs can be obtained by performing a calculation using either the first calculation process corresponding to the interference fringes or the second calculation process not corresponding to the interference fringes depending on the situation. Obtainable. For example, when obtaining an analysis result according to the actual situation, the first calculation process is performed as usual corresponding to the interference fringes, and when the time required for the analysis process is reduced, the second calculation process not corresponding to the interference fringes is performed. Like that.

  In the eighth invention, the distance (interval distance) of the gap (gap) existing between the membrane and the cover member is compared with the reference distance, and if the distance is larger than the reference distance, the second calculation process is performed. Since the calculation is performed in the above, automation for calculation processing selection can be introduced based on the interval distance. That is, the operator can select which of the first calculation process and the second calculation process is used for the calculation in consideration of the characteristics of the sample to be analyzed and the time available for the analysis. Depending on the numerical value of, it is known that interference does not occur even when the sample is irradiated with light, so which calculation processing is used depending on the magnitude relationship between the interval distance and the reference distance that becomes the interference occurrence boundary. If it is, it will be possible to determine whether the process can proceed appropriately. It is preferable to use the dimension determined by the specification of the sample to be analyzed as the value of the distance, and the reference distance is a value around 100 μm, which is a general dimension that eliminates interference fringes. Is preferred.

  In the ninth invention, since the value of the reference distance which becomes a comparison reference with respect to the interval distance is changed, there are various kinds of determination conditions for determining which of the first calculation process and the second calculation process is used for the calculation. Thus, it is possible to appropriately change in consideration of the sample characteristics, and it is possible to set flexible conditions according to the sample. That is, depending on the level required for the analysis, the second calculation process corresponding to the absence of interference may be used instead of the first calculation process corresponding to the presence of interference. Changes can be made as appropriate to enable smooth analysis according to the situation.

  In the tenth invention, at the start of analysis, a plurality of types of models corresponding to the sample having the light-transmitting substrate are prepared (stored), and prepared according to the thickness dimension of the received sample. Since an appropriate model for analysis is selected from a plurality of placed models, efficient analysis processing can be performed. That is, when the light is transmitted through the translucent substrate, a reflection form corresponding to any of the prepared models occurs, so without using a model deviating from the actual reflection form in the sample, Perform calculations based on the appropriate model.

In the eleventh aspect of the invention, in the calculation process using the model, either the first calculation process corresponding to the interference fringes or the second calculation process not corresponding to the interference fringes is used. Even if the characteristic is such that interference fringes are generated by irradiation, analysis according to the required analysis level can be performed. For example, if priority is given to ending the analysis in a short time, it is not necessary to perform detailed measurement and the time required for measurement can be shortened, and the analysis time can be shortened by performing calculations in the second calculation process. Can also be planned.
In the present invention, since the second calculation process is performed when the received interval distance is larger than the reference distance, it is determined whether the operator performs the calculation in the first calculation process or the second calculation process. It is not necessary to give an instruction, and an efficient analysis process can be realized by reducing an operator's operation burden on a sample having a complicated configuration.

In the first invention, since light is irradiated toward the light-transmitting substrate of the sample, light can be applied to the film located inside the cover member, and the characteristics of the film can be reliably measured.
In the second invention, since at least one of the first model and the second model is applied as a model used for the analysis, an efficient analysis can be performed using a model corresponding to the actual reflection form.
In the third invention, when the cover member of the sample has translucency, the analysis is performed by including at least one of the first model to the third model. Therefore, a model that does not match the actual reflection form is used. Therefore, efficient analysis processing can be realized.

In the fourth invention, when the cover member covering the sample film is translucent, the cover member can be irradiated with light so that the light is applied to the inner film through the cover member. The film characteristics can be measured reliably.
In the fifth aspect of the invention, the analysis is performed using the model corresponding to the reflection form assumed for the light irradiated toward the cover member, so that wasteful calculation can be omitted as much as possible and the efficiency of the analysis process can be improved.
In the sixth invention, even when a plurality of models to be used for analysis are selected, the most appropriate model can be specified based on the calculated mean square error, and a good analysis result can be obtained.

In the seventh invention, since the calculation is performed using either the first calculation process corresponding to the interference fringes or the second calculation process not corresponding to the interference fringes, the user can analyze the sample in which the interference fringes are generated. The analysis means according to the needs of the user can be selected, and the convenience for the user can be improved.
In the eighth invention, when the distance from the film of the sample to the cover member is larger than the reference distance, the second calculation process is performed, so that the process selection related to the calculation can be automated, and the measurement time and the analysis time can be shortened. I can plan.
In the ninth invention, since the value of the reference distance is changed, it is possible to provide a setting specification that precisely corresponds to the user's needs by changing the determination criterion of the arithmetic processing according to the required level for analysis.

In the tenth invention, an appropriate analysis process is selected from a plurality of types of models in accordance with the thickness dimension of the received sample, so that efficient analysis processing can be performed.
In the eleventh aspect of the invention, in the calculation process using the model, either the first calculation process corresponding to the interference fringes or the second calculation process not corresponding to the interference fringes is used. When the characteristics are such that interference fringes are generated by irradiation, the analysis processing according to the required analysis level can proceed, and particularly when the second calculation processing is selected, the time required for the calculation can be shortened.
In the present invention, when the received interval distance is larger than the reference distance, the second calculation process is automatically performed, so that the operation burden on the operator can be reduced and the analysis process can proceed smoothly.

  FIG. 1 is a schematic diagram showing an overall configuration of a sample analyzer 1 including an ellipsometer (corresponding to a measuring instrument) according to an embodiment of the present invention. The sample analyzer 1 irradiates a sample with a plurality of films laminated with polarized light, acquires the light reflected by the sample and measures the polarization state of the reflected light, and based on the measurement result and a model corresponding to the sample. The characteristics of each film layer of the sample are analyzed. In the present embodiment, a case where the organic EL element 50 is analyzed as a sample by the sample analysis apparatus 1 will be described. In the sample analyzer 1, a polarimeter can be used as a measuring instrument instead of the ellipsometer.

  FIG. 2A shows an example of the organic EL element 50 to be analyzed. This organic EL element 50 is of a production type, and has an appearance in which two glass plate members (glass substrates) are bonded together. The structure of the organic EL element 50 is such that an organic film 56 is formed on one surface 51a of a glass substrate 51 (corresponding to a translucent substrate) which is one glass plate material, while a cover glass 57 (which is a cover member) is formed on the other glass plate material. Correspondingly, a concave portion 57d for accommodating the organic film 56 is provided, and the surface 57b provided with the concave portion 57d is bonded to one surface 51a of the glass substrate 51 with an adhesive 61 to integrate the two. Note that the inside of the recess 57 d sealed by bonding the glass substrate 51 and the cover glass 57 is evacuated or filled with a rare gas (for example, nitrogen gas) to protect the organic film 56.

  FIG. 2B shows a detailed structure of the organic film 56 housed in the recess 57d. The organic film 56 has a hole transport layer 52 and a light emitting layer (Emitting layer) on an anode (ITO) 58 which is a transparent electrode disposed on one surface 51a of the glass substrate 51 having translucency. A total of four film layers, 53, a hole blocking layer 54, and an electron transport layer 55, are sequentially stacked. The organic film 56 has a cathode 59 disposed on a surface 56 a facing the cover glass 57.

  The organic film 56 is housed in the recess 57 d with a gap (gap) therebetween, and a space 60 is formed between the organic film 56 and the cover portion 57 a of the cover glass 57 covering the surface 56 a of the organic film 56. The thickness dimension D of the space 60 (the vertical dimension from the surface 56a of the organic film 56 to the inner surface 57c of the cover portion 57a, which varies depending on the specifications of the organic EL element 50), is generally 10 μm or more and 400 μm. The thickness dimension D is often set in the following range. The glass substrate 51 and the cover glass 57 are often used with thicknesses T of 0.5 mm, 0.7 mm, and 1.1 mm (0.7 mm is most common), and therefore the entire organic EL element 50 is used. The thickness (2T) is generally in the range of 1.0 mm to 2.2 mm.

The sample analysis apparatus 1 for analyzing the organic film 56 of the organic EL element 50 having the structure described above has the configuration shown in FIG. 1 and is roughly divided into a measurement analysis system part and a drive system part.
As a part of the measurement analysis system, the sample analyzer 1 connects the xenon lamp 2 and the light irradiator 3 with the first optical fiber cable 15a, and goes to the sample (organic EL element 50) placed on the stage 4 (sample stage). A configuration is adopted in which light in a polarized state is irradiated so that the light is incident on the sample, and the light reflected by the sample is captured by the light acquisition unit 5. The light acquisition unit 5 is connected to the spectroscope 7 via the second optical fiber cable 15b. The spectroscope 7 performs measurement for each wavelength and transmits the measurement result to the data acquisition unit 8 as an analog signal. The data fetcher 8 converts the analog signal into a required value and transmits it to the computer 10 for analysis by the computer 10.

  In addition, the sample analyzer 1 includes a first motor M1 to a sixth motor M6 in the stage 4, the light irradiator 3, the light acquirer 5, and the spectroscope 7 as drive system parts, respectively. By controlling the drive by the motor controller 9 connected to the computer 10, the stage 4, the light irradiator 3, the light acquirer 5, and the spectroscope 7 are changed to appropriate positions and postures according to the measurement. The motor controller 9 performs drive control of the motors M <b> 1 to M <b> 6 based on instructions output from the computer 10. In the sample analyzer 1, the part corresponding to the ellipsometer mainly includes a xenon lamp 2, a light irradiator 3, a stage 4, a light acquisition device 5, a spectrometer 7, a data acquisition device 8, a motor controller 9, and This is a range constituted by the motors M1 to M6.

  Next, each part mentioned above of sample analysis device 1 is explained in full detail in order. First, the xenon lamp 2 is a light source, generates white light including a plurality of wavelength components, and sends the generated white light to the light irradiator 3 via the first optical fiber cable 15a.

  The light irradiator 3 is disposed on a semicircular arc-shaped rail 6 and has a polarizer 3a inside. The light irradiator 3 polarizes white light with the polarizer 3a and irradiates the sample with polarized light. Further, the light irradiator 3 moves along the rail 6 by driving the fourth motor M4, and the angle (incident angle φ) of the irradiating light with respect to the perpendicular H of the stage surface 4a of the stage 4 can be adjusted. ing.

  The stage 4 is slidably disposed on a moving rail portion (not shown), and is driven by the first motor M1 to the third motor M3 to move the stage 4 in the X direction and the Y direction in FIG. In the Z direction which is the height direction) and the height direction. By moving the stage 4, the location where the light is incident on the sample can be changed as appropriate, and the surface analysis of the sample can be performed. The stage surface 4a on which the sample of the stage 4 is placed is black to prevent light reflection.

  In this embodiment, in order to irradiate light to the organic film 56 covered with the cover glass 57 of the organic EL element 50, the outer surface 57f of the cover portion 57a of the cover glass 57 is the stage surface of the stage 4 as shown in FIG. The organic EL element 50 is placed on the stage 4 with the top and bottom reversed so as to be in contact with 4a. By irradiating light from the light irradiator 3 in this state, light enters from the back surface 51 b of the glass substrate 51 of the organic EL element 50 and passes through the translucent glass substrate 51 to reach the organic film 56. 3, illustration of the anode 58 and the cathode 59 of the organic EL element 50 is omitted (the same applies to FIG. 2A and FIG. 10 described later).

  Moreover, the light acquisition device 5 acquires the light reflected by the sample (organic EL element 50), and measures the polarization state of the acquired light. Similar to the light irradiator 3, the light acquirer 5 is disposed on the rail 6, and includes a PEM (Photo Elastic Modulator) 5a and an analyzer 5b, and is reflected by the sample. Light is guided to the analyzer 5b through the PEM 5a. Further, the light acquisition unit 5 can be moved along the rail 6 in the directions of arrows A1 and A2 in FIG. 3 by driving the fifth motor M5, and the reflection angle is basically interlocked with the movement of the light irradiation unit 3. The motor controller 9 controls so that φ and the incident angle φ are the same. The PEM 5a built in the light acquisition unit 5 obtains elliptically polarized light from linearly polarized light by phase-modulating the captured light at a required frequency (for example, 50 kHz). The analyzer 5b selectively acquires polarized light from various polarized light phase-modulated by the PEM 5a and measures it.

  The spectroscope 7 includes a reflection mirror, a diffraction grating, a photomultiplier (PMT: photomultiplier tube), a control unit, and the like, and reflects light transmitted from the light acquisition device 5 through the second optical fiber cable 15b with the reflection mirror. To the diffraction grating. The diffraction grating changes the wavelength of the emitted light by changing the angle by the sixth motor M6. The light traveling into the spectroscope 7 is amplified by the PMT, and the measured signal (light) is stabilized even when the amount of light is small. Further, the control unit performs a process of generating an analog signal corresponding to the measured wavelength and sending it to the data fetcher 8. In the case where a polarimeter is used as a measuring instrument, a configuration in which a photodiode array (PDA) is combined may be used.

The data acquisition device 8 calculates the amplitude ratio Ψ and the phase difference Δ of the polarization state (p-polarized light, s-polarized light) of the reflected light based on the signal from the spectroscope 7, and sends the calculated results to the computer 10. Note that the amplitude ratio Ψ and the phase difference Δ satisfy the relationship of the following formula (1) with respect to the amplitude reflection coefficient Rp of p-polarized light and the amplitude reflection coefficient Rs of s-polarized light.
Rp / Rs = tan Ψ · exp (i · Δ) (1)
However, i is an imaginary unit (the same applies hereinafter). Rp / Rs is called the polarization change amount ρ.

  The computer 10 included in the sample analyzer 1 analyzes the sample based on the amplitude ratio Ψ and the phase difference Δ of the polarization state obtained by the data acquisition unit 8 and a model corresponding to the sample, and the stage 4 Control the movement of

  The computer 10 itself includes a computer main body 11, a display 12, a keyboard 13, a mouse 14, and the like. The computer main body 11 connects a CPU 11a, a storage unit 11b, a RAM 11c, and a ROM 11d via an internal bus. The CPU 11a performs various processes related to the computer 10 to be described later according to various computer programs stored in the storage unit 11b. The RAM 11c temporarily stores various data related to the process, and the ROM 11d has functions of the computer 10. Such contents are stored.

  The storage unit 11b of the computer 10 stores in advance various programs such as a computer program for sample analysis and a computer program for movement control of the stage 4, and data of various menu images to be displayed on the display 12. Used for known data related to samples, model patterns of different structures, multiple dispersion formulas used to create models, created models, reference data for various samples, and comparison processing related to interference fringes The reference value and the like are stored.

  Regarding the analysis of the sample (organic EL element 50), the computer 10 analyzes the refractive index and the extinction coefficient as the optical characteristics of each film layer (52 to 55) constituting the organic film 56 of the organic EL element 50, and each film. The film thickness of the layers (52 to 55) is also analyzed.

Specifically, when the computer 10 determines the complex refractive index of the surrounding atmosphere of the glass substrate 51, the cover glass 57, and the organic EL element 50 from the measured amplitude ratio Ψ and phase difference Δ, the storage unit 11b By using a modeling program stored in advance, a model corresponding to the sample item set by the user and the material structure of the organic EL element 50 is created and stored in the storage unit 11b, and stored in the analysis stage. The thickness and complex refractive index of each of the film layers 52 to 55 of the organic film 56 are obtained using the model that is used. When the complex refractive index N is the refractive index n and extinction coefficient k of the film layer to be analyzed, the relationship expressed by the following formula (2) is established.
N = n−ik (2)

Further, when the incident angle is φ and the wavelength of the light irradiated by the light irradiator 3 is λ, the amplitude ratio Ψ and the phase difference Δ measured by the ellipsometer output from the data acquisition device 8 are the film layer 52 to be analyzed. The following equation (3) is established for the film thickness d, the refractive index n, and the extinction coefficient k of .about.55.
(D, n, k) = F (ρ) = F (Ψ (λ, φ), Δ (λ, φ)) (3)

The computer 10 uses a dispersion formula indicating the wavelength dependency of the complex dielectric constant having a plurality of parameters and the film thicknesses of the film layers 52 to 55 to be analyzed, and a model obtained by theoretical calculation from the stored model. Spectrum (Ψ _M (λ _i ), Δ _M (λ _i )) and measurement spectrum (Ψ _E (λ _i ), Δ _E (λ _i )) related to the measurement result output from the data acquisition unit 8 Processing (fitting) is performed to change the film thickness, dispersion parameters, etc. so as to minimize the difference. An example of the applied dispersion formula is shown in the following formula (4).

In equation (4), ε on the left side represents a complex dielectric constant, ε _∞ and ε _s represent dielectric constants, Γ ₀ , Γ _D , and γ _j represent damping factors for viscous forces, ω _oj , ω _t and ω _p represent natural angular frequencies (oscillator frequency, transverse frequency, plasma frequency). Note that ε _∞ is a dielectric constant at a high frequency (high frequency dielectric constant), and ε _s is a dielectric constant at a low frequency (static dielectric constant). The complex dielectric constant ε (corresponding to ε (λ)) and the complex refractive index N (corresponding to N (λ)) satisfy the relationship of the following mathematical formula (5).
ε (λ) = N ² (λ) (5)

The fitting will be briefly described. When the organic EL element 50 is measured, T measurement data pairs are represented by Exp (i = 1, 2,..., T), and T model calculation data pairs are represented by Mod ( The measurement error is normally distributed when i = 1, 2,..., T), and the mean square error χ ² according to the least square method when the standard deviation is σ _i is given by the following equation (6). Desired. P is the number of parameters. When the value of the mean square error χ ² is small, it means that the degree of coincidence between the measurement result and the created model is large. Therefore, when comparing multiple models, the one with the smallest mean square error χ ² is best. Corresponds to the model.

  A series of processes related to sample analysis performed by the computer 10 described above is defined in a computer program for sample analysis stored in the storage unit 11b. This computer program includes processing for displaying a menu for setting a film thickness or the like on the screen of the display 12 as a condition item of a model created corresponding to the physical properties of the sample.

  In addition, the sample analysis apparatus 1 according to the present embodiment stores model types (model structures) created in advance so as to correspond to a plurality of reflection forms in the sample in the storage unit 11b, and these model types. Is read out based on processing defined by a computer program (modeling program) stored in the storage unit 11b and used for analysis.

  That is, in this embodiment, since the organic EL element 50 is measured in the form as shown in FIG. 3, generally three kinds are assumed as the form in which the light K irradiated to the organic EL element 50 is reflected. The first form is a case where the light K incident on the organic EL element 50 is reflected at the boundary between the organic film 56 and the space 60 (a portion corresponding to the surface 56a of the organic film 56) (reflected light K1 in FIG. 3). The second form is a case where the light K passes through the organic film 56 and the space 60 and is reflected by the inner surface 57c of the cover glass 57 (the optical path of the reflected light K2 in FIG. 3). Is a case where the light passes through the translucent cover glass 57 and is reflected at the boundary between the cover glass 57 and the stage 4 (where the outer surface 57f of the cover glass 57 and the stage surface 4a of the stage 4 are in contact) (in FIG. 3). , The optical path of the reflected light K3).

  In practice, as shown in FIG. 3, the reflection at the point P1 on the surface of the glass substrate, the reflection at the point P2 that is the boundary between the glass substrate 51 and the organic film 56, and multiple reflection are also included. The reflection at P2 is not directly related to the selection of the model used for the analysis, and is not treated in this embodiment. Further, the light K, the reflected light K1 to K3, and the like are refracted at the time of incidence on the glass substrate 51 and the organic film 56 and also refracted at the time of emission, but at this time, the angles at the time of incidence and the time of emission are the same. Furthermore, whether or not all of the reflected lights K1 to K3 including multiple reflections are measured depends on the thickness dimension of the sample. Therefore, the sample analyzer 1 also selects the type of model used for the analysis according to the thickness dimension of the sample. is doing.

  In the three reflection modes described above, the layers through which light passes are different from each other. Therefore, it is necessary to select a model used for analysis according to the reflection mode in actual measurement. FIG. 4A shows a model m10 having a structure corresponding to the reflected light K1 in FIG. Since the model m10 corresponds to the reflection on the organic film 56, the space 60 positioned below the organic film 56 is formed as a void layer (gap layer), and the void layer S1 (considered as a substrate) has an organic film layer L1. (Corresponding to the organic film 56), the glass layer L2 (corresponding to the portion having no surface roughness of the glass substrate 51), and the roughness layer L3 (part corresponding to the surface roughness of the glass substrate 51) are overlapped. .

  FIG. 4B shows a model m11 having a structure corresponding to the reflected light K2 in FIG. Since the model m11 corresponds to reflection on the inner surface 57c of the cover glass 57, the material (sealing material) constituting the cover glass 57 is regarded as a substrate, and the sealing material S10 (corresponding to a layer related to the cover member). Void layer L11 (corresponding to the void layer of space 60), organic film layer L12 (corresponding to organic film 56), glass layer L13 (corresponding to the portion having no surface roughness of glass substrate 51), and roughness layer L14 (glass A portion corresponding to the surface roughness of the substrate 51 is overlapped.

  Further, FIG. 4C shows a model m12 having a structure corresponding to the reflected light K3 in FIG. Since the model m12 corresponds to the reflection at the boundary surface between the cover glass 57 and the stage 4, it exists between the cover glass 57 and the stage 4 in FIG. A void layer in the space is regarded as a substrate, and a sealing material layer L21 (corresponding to a material layer constituting the cover glass 57) and a void layer L22 (in the space 60) in the void layer (ambient atmosphere) S20 (substrate). According to the surface roughness of the glass substrate 51), the organic film layer L23 (corresponding to the organic film 56), the glass layer L24 (corresponding to the portion having no surface roughness of the glass substrate 51), and the roughness layer L25. The structure is overlapped.

  In each of the models m10, m11, and m12 described above, the organic film layers L1, L12, and L23 are simply expressed as one film layer in which the film layers 52 to 55 shown in FIG. As in the organic film 56 of the organic EL element 50, the organic film layers L1, L12, and L23 in the modeling of (1) were formed by stacking the hole transport layer 52, the light emitting layer 53, the hole blocking layer 54, and the electron transport layer 55. It is assumed that the film thickness corresponding to each of the film layers 52 to 55 is set. In this manner, by performing modeling according to each of the film layers 52 to 55, the characteristics of the film layers 52 to 55 included in the organic film 56 can be analyzed.

  Since the sample analysis apparatus 1 selects a model having a structure to be used for analysis from the above-described models m10, m11, and m12, in the setting items received from the user for the sample to be analyzed in the preparation stage at the time of sample measurement The thickness dimension of the sample is included. The sample analyzer 1 accepts the thickness dimension of the sample together with the type of the substrate, the film thickness, and the like as the setting items for the sample to be analyzed at the preparation stage by user input, and uses m10 as a model used for the analysis according to the thickness dimension. Select from m11 and m12.

  The relationship between the thickness dimension of the sample and the reflected light that can be measured will be described. When the thickness dimension of the sample to be analyzed is 2.2 mm or more, the reflection direction of the reflected light K3 is deviated and deviates from the measurement range of the light acquisition unit 5. Therefore, since the sample analyzer 1 cannot measure the reflected light K3 with the light acquisition device 5 when the thickness dimension of the sample is 2.2 mm or more, the model m10 and the model shown in FIG. Select m11.

  Further, when the thickness dimension of the sample exceeds 1.0 mm and is less than 2.2 mm, all of the reflected lights K1 to K3 may enter the measurement range of the light acquisition unit 5. Therefore, when the thickness dimension of the sample is more than 1.0 mm and less than 2.2 mm, the sample analyzer 1 uses all models m10, m11, and m12 corresponding to the reflected lights K1 to K3 as the model structure used for the analysis. select.

  Furthermore, even when the thickness dimension of the sample is 1.0 mm or less, all of the reflected lights K1 to K3 may fall within the measurement range of the light acquisition unit 5. Therefore, when the thickness dimension of the sample is 1.0 mm or less, the sample analyzer 1 selects all the models m10, m11, and m12 corresponding to the reflected lights K1 to K3 as the model structure used for the analysis. Depending on the material of the sample, only reflected light K1 or only reflected light K1 and K2 may enter the measurement range. In such a case, only model m10 or two models m10 and m11 are used. The sample analysis apparatus 1 may be selected. After the model type is selected, the sample analyzer 1 creates a specific model to be used for analysis with the model structure selected based on the input items from the user.

  Further, as another feature of the processing content defined by the computer program stored in the sample analyzer 1 according to the present embodiment, a calculation process for obtaining the amplitude ratio (Ψ) and the phase difference (Δ) for the model used for the analysis. Can be performed in two ways. In the first calculation process (first calculation process), the calculation result (amplitude ratio (Ψ) and phase difference (Δ)) corresponding to the measurement range of the sample is calculated faithfully with respect to the model used for analysis. Is to get. The second calculation process (second calculation process) is to perform an operation on the amplitude based on a model used for analysis and obtain a calculation result quickly. The sample analyzer 1 includes a thickness dimension D (corresponding to an interval distance) of the space 60 of the organic EL element 50 shown in FIGS. 2A and 2B to be analyzed, and a reference value stored in the storage unit 11b of the computer 10. Compared with (corresponding to the reference distance), the result of the comparison determines whether the calculation is performed in the first calculation process or the second calculation process.

  The sample analyzer 1 includes the thickness dimension D (a numerical value based on the specifications of the organic EL element 50) and the reference value of the space 60 in the setting items received from the user for the organic EL element 50 to be analyzed in the measurement preparation stage. The second calculation process is performed when the thickness dimension D is larger than the reference value, and the first calculation process is performed when the thickness dimension D is equal to or less than the reference value. In addition, the second calculation process appropriately averages values theoretically obtained from the model selected based on the items input in the measurement preparation stage using a well-known calculation method, so that the amplitude ratio ( The graph related to (Ψ) and phase difference (Δ) is a smooth curve, and does not correspond exactly to the interference fringes even when the model to be analyzed corresponds to a sample that generates interference fringes by light irradiation. Since the calculation is performed in step 1, the processing time for the calculation can be shortened compared to the first calculation process, and the time required for measurement is also shortened. On the other hand, since the first calculation processing is performed faithfully to the model as in the conventional case, if the model to be analyzed is for a sample that generates interference fringes by light irradiation, it corresponds to the interference fringes. As a result, the analysis time becomes longer and the measurement time becomes longer.

Next, a series of processing procedures relating to a method (sample analysis method) for analyzing the organic EL element 50 shown in FIG. 2 by the sample analysis apparatus 1 having the above-described configuration will be described based on the flowchart of FIG.
First, the organic EL element 50 is placed on the stage 4 of the sample analyzer 1 as shown in FIG. 3 (S1).

  Next, in order to set conditions, the sample analyzer 1 receives input of items necessary for analysis from the user (S2). In accepting the item, the sample analyzer 1 displays a setting menu 20 as shown in FIG. The setting menu 20 includes a thickness input column 21 for the space 60, a film thickness input column 22 for the organic film 56, and an input column 23 for the substrate (cover glass 57) corresponding to the structure of the organic EL element 50 in FIG. In particular, regarding the input field 21 for the thickness of the space (gap), the numerical value (void) input field 21a according to the specifications of the organic EL element 50 and the determination of the first calculation process or the second calculation process A reference value input field 21b is provided. In the setting menu 20 of FIG. 5, the input of the film thickness is simplified and only the input field 22 is shown, but actually, an input field is provided for each layer according to the type of the organic film layer. .

  In the organic EL element 50, it has been found in previous studies that interference fringes are likely to occur when the thickness dimension D of the space 60 is smaller than 100 μm. Therefore, it is preferable to set 100 μm as the reference value. The setting menu 20 also accepts other items not shown in FIG. 5 (measurement point, incident angle φ, thickness of the glass substrate 51, thickness of the cover glass 57, etc.).

  Then, the sample analyzer 1 determines the organic EL element 50 (sample) based on the thickness (T) of the glass substrate 51 and the thickness (T) of the cover glass 57 among the input items (see FIG. 2A). It is determined whether the thickness dimension (2T) is 1.0 mm or less, a range of more than 1.0 mm and less than 2.2 mm, or 2.2 mm or more (S3).

  When it is determined that the thickness dimension (2T) is 1.0 mm or less (S3: 1.0 mm or less), the sample analyzer 1 uses the models m10 to m10 shown in FIGS. 4A to 4C as model structures used for the analysis. m12 is selected (S4). Further, when it is determined that the thickness dimension (2T) is more than 1.0 mm and less than 2.2 mm (S3: more than 1.0 mm and less than 2.2 mm), the sample analysis apparatus 1 is shown in FIG. The models m10 to m12 of a) to (c) are selected (S5). Furthermore, when it is determined that the thickness dimension (2T) is 2.2 mm or more (S3: 2.2 mm or more), the sample analyzer 1 uses the model m10 shown in FIGS. 4A and 4B as the model structure used for the analysis. , M11 is selected (S6).

  After the model selection, the sample analysis apparatus 1 will create a model for analysis according to the item input with the selected model structure, and the model structure used for the analysis in the above-described discrimination process is as follows. Since it corresponds to the reflection form (see FIG. 3) in the sample to be analyzed, it contributes to the reduction of the processing load in the later analysis processing steps (S10 to S12).

Next, the sample analyzer 1 performs provisional irradiation in order to appropriately irradiate the sample (organic EL element 50) placed on the stage 4 and obtain reflected light having sufficient intensity for measurement. The height of the stage 4 is adjusted (S7). After adjusting the height of the stage 4, the sample analyzer 1 irradiates the organic EL element 50 with light in a polarized state as main irradiation in order to measure the organic EL element 50 (sample) (S 8), and the glass substrate 51. The reflected light (K1 to K3) emitted from the light is acquired and the polarization state (amplitude ratio Ψ _E , phase difference Δ _E ) of the light is measured (S9). Note that Ψ _E represents the measured amplitude ratio, and Δ _E represents the measured phase difference.

Further, the sample analyzer 1 calculates the amplitude ratio Ψ _M and the phase difference Δ _M in a range corresponding to the measurement range based on the model established with the selected structure (S10). At this time, the sample analyzer 1 compares the input thickness dimension D of the space 60 with the reference value, and obtains the amplitude ratio Ψ _M and the phase difference Δ _M in the first calculation process or the second calculation process. Here, Ψ _M represents the amplitude ratio obtained from the model, and Δ _M represents the phase difference obtained from the model. Note that, when there are a plurality of selected models, the sample analyzer 1 performs such calculation for all the models.

The graph of FIG. 8 shows the amplitude ratio Ψ _E and the phase difference Δ _E measured from the organic EL element 50 whose thickness dimension D of the space 60 is 60 μm, and the amplitude ratio Ψ _M and the phase difference Δ _M obtained from the model. The contents shown are shown. The measured amplitude ratio Ψ _E and phase difference Δ _E are represented by dots, and the amplitude ratio Ψ _M and phase difference Δ _M obtained from the model are represented by curves (the phase difference is a solid line and the amplitude ratio is a broken line). Yes. Since the organic EL element 50 according to the graph of FIG. 8 has a thickness dimension D of 60 μm, the sample analyzer 1 obtains the amplitude ratio Ψ _M and the phase difference Δ _M by the first calculation process, and the amplitude ratio Ψ _M , since the phase difference delta _M being faithfully calculated in accordance with the model, a range such as dots measuring points according to the resolution of the spectrometer is an amplitude (e.g., photon energy (photon energy) the following 2.2eV (Range), the curve representing the amplitude ratio Ψ _M and the phase difference Δ _M also swings up and down, and corresponds to the occurrence of interference fringes. In addition, since the first calculation process calculates the details of the amplitude in this way, the thickness of the space can be calculated and the processing time is longer than that of the second calculation process.

On the other hand, the graph of FIG. 7 shows the result of performing the second calculation process on the model of the organic EL element 50 according to the graph of FIG. 8 for comparison. By obtaining the amplitude ratio Ψ _M and the phase difference Δ _M by the second calculation process, the amplitude ratio Ψ _M and the phase difference Δ _M are shaped so as to pass through the middle of the dots that are measurement points.

The graph of FIG. 9 shows the result of performing the first calculation process on the model of the organic EL element 50 in which the thickness dimension D of the space 60 is 10 μm, and is the same as the measurement point dot that swings up and down. In addition, the curves representing the amplitude ratio Ψ _M and the phase difference Δ _M obtained from the model also have large amplitudes in the vertical direction (particularly the amplitude of the amplitude ratio represented by the broken line is large).

  Returning to the flowchart of FIG. 6, the explanation of the processing procedure of the sample analysis method will be continued. The measured value (measurement result) by the ellipsometer and the calculated value obtained from the model are compared (S11), and the computer 10 is compared. The thickness of each layer in the model and the parameters of the dispersion formula are fitted so that the difference between the values is small (S12).

  Note that, in the above-described steps (S10 to S12) for a plurality of models used for analysis, all models are fitted to calculate the mean square error according to the least square method, and the model according to the lowest mean square error value is calculated. Alternatively, a model in which the value of the mean square error that falls within the range from the minimum value to the maximum value of the film thickness preset in the computer 10 is selected is selected.

  In the model selected in this manner, if the difference obtained by the least square method by final fitting falls within a required value (if it becomes sufficiently small), the films of the film layers 52 to 55 according to the model used at that time After confirming whether the thickness or the like is a physically impossible value, the model at that time is determined as the best model (S13). Finally, the sample analyzing apparatus 1 refers to the film thicknesses, dispersion parameters, voids, and the like of the respective film layers 52 to 55 according to the best model, and thereby each film layer 52 of the organic film 56 of the organic EL element 50. The film thickness, optical constant (refractive index n, extinction coefficient k), etc. are obtained for each film layer as the characteristics of .about.55 (S14). In addition, although the difference calculated | required by the least squares method is settled in a required value, when the film thickness of each film layer 52-55 which concerns on the model at that time is a numerical value which is physically impossible, all Fitting (processing after S10) is performed again by changing the numerical values related to the model configuration.

  As described above, in the present invention, even when the film to be analyzed of the organic EL element 50 is covered, the organic film 56 is irradiated with light toward the glass substrate 51 and applied to the organic film 56. Each film layer can be measured with an ellipsometer. Moreover, since the sample analysis apparatus 1 uses the first calculation process and the second calculation process properly according to the above-described conditions, the calculation process related to the model is efficiently advanced and the thickness of the sample to be analyzed is determined. Since the model structure type is narrowed down, the burden of analysis processing can be reduced.

  The sample analysis apparatus 1 and the sample analysis method according to the present invention are not limited to the above-described embodiments, and various modifications can be applied. For example, when the cover glass 57 of the organic EL element 50 is formed of an opaque material (metal, synthetic resin, etc.), the reflection form such as the reflected light K3 shown in FIG. 4A, the model m10 shown in FIG. 4A or the model m11 shown in FIG. 4B or both of the models m11 corresponding to the reflected light K1 or the reflected light K2 are used for analysis by comparing the thickness dimensions of the sample. To make a selection.

  In the above description, the setting menu 20 shown in FIG. 5 has been described by setting 100 μm in the reference value input field 21b. Of course, other numerical values may be set in accordance with the sample and measurement conditions. When a new numerical value is input in a state where the numerical value is set, the sample analyzer 1 performs a step of changing the reference value, and thereafter, the thickness of the space 60 with the changed new value is used. Comparison with the dimension D will be performed. By making it possible to change the reference value in this way, it is possible to smoothly proceed with processing when measuring samples with slightly different influences of measurement conditions and interference fringe conditions. In addition, it is preferable to set an appropriate value (for example, 100 μm as the reference value) as a default value for a predetermined item including the reference value from the viewpoint of reducing the input burden on the user.

  Furthermore, instead of the sample analyzer 1 determining whether to perform the first calculation process or the second calculation process by comparison with the thickness dimension D of the space 60, the user may be able to select at any time. In this case, a selection button for instructing whether to perform the process in the first calculation process or the second calculation process is provided in the setting menu before measurement, and the sample analyzer 1 performs the first calculation process in accordance with an instruction received from the user. Alternatively, the process is performed in either of the second calculation processes.

  In addition to the production type organic EL element 50 shown in FIGS. 2 (a) and 2 (b), the sample analysis apparatus 1 of the present embodiment also applies to the research and development type organic EL element 70 shown in FIG. Analysis can be performed in the same manner. The difference between the research-and-development type organic EL element 70 and the production-type organic EL element 50 is that the organic EL element 70 is formed on a glass substrate 71 having a thickness T1 and a cap-like sealing cap 77 (high The point T2) is attached with an adhesive 81.

  The sealing cap 77 has a cover part 77 a and a side wall part 77 b so as to cover the organic film 76 (multiple layers 72 to 75) and the electrodes 58 and 59 provided on the one surface 51 a of the glass substrate 71. It is concave. In addition, the sealing cap 77 generates a space 80 having a thickness dimension D with a gap (gap) from the uppermost surface 76a of the organic film 76 to the inner surface 57c of the cover portion 77a. When the organic EL element 70 of FIG. 10 is analyzed by the sample analyzer 1, if a numerical value obtained by adding the thickness T1 of the glass substrate 71 and the height T2 of the sealing cap 77 is input as the thickness dimension of the sample, The point can be analyzed by handling in the same manner as the organic EL formation 50 shown in FIGS.

  Furthermore, when the cover glass 57 of the organic EL element 50 has translucency, in addition to placing the organic EL element 50 on the stage 4 in the form as shown in FIG. 3, as shown in FIG. The organic EL element 50 may be placed with the glass substrate 51 facing down so that the substrate 51 contacts the stage surface 4 a of the stage 4. In this case, the sample analyzer 1 irradiates the cover glass 57 with the polarized light K, and the light K that has passed through the cover glass 57 and the space 60 has a plurality of film layers 52 to 55 (FIG. 2B). The organic film 56 constituted by (see) is reached. Further, the light K passes through the organic film 56 and then reflects at the boundary between the organic film 56 and the glass substrate 51 (in the case of reflected light K10) as shown in FIG. In some cases, the light is reflected at the boundary between 51 and the stage 4 (in the case of reflected light K11). In addition, any reflected light K10 and K11 are radiate | emitted from the cover glass 57, are acquired with the light acquisition device 5, and a polarization state is measured.

  11 also includes reflection on the surface of the cover glass (P10), reflection on the inner surface of the cover glass (P20), reflection on the surface of the organic film (P30), and multiple reflection. Neither reflection (P10, P20, P30) is omitted because it is not directly related to the selection of the model used for the analysis.

  Further, when analyzing the sample in the mounting form of the organic EL element 50 shown in FIG. 11, it is necessary to use a model having a structure corresponding to the above-described reflected lights K10 and K11 as a model used for the analysis. FIG. 12A shows a model m20 having a structure corresponding to the reflected light K10. The model m20 uses the lowermost glass substrate 51 as a substrate (S30), on which an organic film layer L31 (corresponding to the organic film 56), a void layer L32 (corresponding to the space 60), and a sealing material layer L33 (cover) The glass 57 corresponds to a portion having no surface roughness) and the roughness layer L34 (a portion corresponding to the surface roughness of the cover glass 57) is overlapped. Note that the thicknesses d31 to d34 of each layer of the model m30 are set by values input from the user in the preparation stage.

  On the other hand, FIG. 12B shows a model m21 having a structure corresponding to the reflected light K11. In the model m21, a medium (in FIG. 11, a void layer in a space existing between the glass substrate 51 and the stage 4) constituting the ambient atmosphere below the glass substrate 51 is regarded as a substrate, and the void layer S40 (substrate ) Glass layer L41 (corresponding to glass substrate 51), organic film layer L42 (corresponding to organic film 56), void layer L43 (corresponding to space 60), sealing material layer L44 (cover glass 57 has no surface roughness) And a roughness layer L45 (a portion corresponding to the surface roughness of the cover glass 57) overlap each other. The thicknesses d41 to d45 of each layer of the model m21 are set according to values input from the user in the preparation stage.

  In the mounting form shown in FIG. 11, only one of the reflected lights K10 and K11 (theoretically only K10) or both may be measured according to the thickness dimension of the organic EL element 50. As the processing steps (S3 to S6) in the flowchart of FIG. 6, the apparatus 1 uses one of models m20 and m21 (theoretically model m20) as a model structure used for analysis according to the thickness dimension of the sample, or both. Make a selection. Note that after the model is selected, analysis is performed by performing the same processing as in the flowchart of FIG.

In addition, in the mounting form of the organic EL element 50 shown in FIG. 11, in obtaining values (amplitude ratio and phase difference) related to the model, the thickness dimension D of the space 60 is compared with the reference value or according to a user instruction. The first calculation process or the second calculation process is performed. The graph shown in FIG. 13 shows the dot of the amplitude ratio Ψ _E and phase difference Δ _E measured for the organic EL element 50 having the thickness dimension D of the space 60 in the mounting form shown in FIG. A curve of the amplitude ratio Ψ _M and the phase difference Δ _M obtained from the structure model by the second arithmetic processing is shown, and the obtained curve has a shape substantially along the measurement point (dot). 11 can also measure and analyze the research and development type organic EL element 70 of FIG. 10, and in that case, a model in which the cover glass 57 is considered as the sealing cap 77 is prepared. (See FIGS. 12 (a) and 12 (b)).

  In addition, the sample analysis apparatus 1 and the sample analysis method according to the present invention can analyze both types of so-called high-molecular organic EL elements and low-molecular organic EL elements with respect to the organic EL element 50, Samples other than the organic EL element have a structure in which a film is laminated on a substrate and is covered with a cover member with a distance from the film, and at least one of the substrate or the cover member is a light-transmitting sample. The analysis can be made in the same form as the organic EL element 50 described above.

1 is an overall configuration diagram of a sample analyzer according to an embodiment of the present invention. (A) is a schematic sectional drawing which shows the structure of the organic EL element (production type) used as a sample, (b) is sectional drawing to which the principal part of the organic EL element (production type) was expanded. It is the schematic which shows the mounting form in the case of irradiating toward the glass substrate of an organic EL element. (A) is a schematic diagram showing a model of a structure corresponding to the reflected light K1 in FIG. 3, (b) is a schematic diagram showing a model of a structure corresponding to the reflected light K2 in FIG. 3, and (c) is a reflection in FIG. It is the schematic which shows the model of the structure corresponding to the light K3. It is the schematic which shows an example of a setting menu. It is a flowchart which shows a series of processing procedures of a sample analysis method. It is a graph which shows the measurement result at the time of irradiating light from a glass substrate to the sample (organic EL element) whose thickness of space is 60 micrometers, and the calculation result by a 2nd calculation process. It is a graph which shows the measurement result at the time of irradiating light from a glass substrate to the sample (organic EL element) whose space thickness is 60 micrometers, and the calculation result by a 1st calculation process. It is a graph which shows the measurement result at the time of irradiating light from a glass substrate to the sample (organic EL element) whose space thickness is 10 micrometers, and the calculation result by a 1st calculation process. It is the schematic which shows the structure of a research-and-development type organic EL element. It is the schematic which shows the mounting form in the case of irradiating toward the cover glass of an organic EL element. (A) is a schematic diagram showing a model of a structure corresponding to the reflected light K10 in FIG. 11, and (b) is a schematic diagram showing a model of a structure corresponding to the reflected light K11 in FIG. It is a graph which shows the measurement result at the time of irradiating light from a cover glass to the sample (organic EL element) whose space thickness is 60 micrometers, and the calculation result by a 2nd calculation process. (A) is a graph which shows an example of the measurement result of an amplitude ratio and a phase difference, (b) is a graph which shows the value finely amplified by the influence of the interference fringe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample analyzer 2 Xenon lamp 3 Light irradiator 4 Stage 5 Light acquisition device 7 Spectrometer 8 Data acquisition machine 9 Motor controller 10 Computer 20 Setting menu 50 Organic EL element (production type)
51 Glass substrate 56 Organic film 57 Cover glass 60 Space (gap)
70 Organic EL device (Research and development type)

Claims (13)

The optical characteristics of a sample in which a plurality of films laminated on a light-transmitting substrate are covered with a cover member at an interval are measured with a measuring instrument that emits polarized light, and the model corresponding to the sample and the measurement of the measuring instrument are measured. A sample analysis method for analyzing characteristics of each film layer of a sample based on a result,
Placing the sample in which one surface of the translucent substrate and one surface of the cover member are bonded together so that the outer surface of the cover member is in contact with the stage;
Irradiating polarized light to the light-transmitting substrate of the sample;
Obtaining light reflected from the sample;
And a step of measuring the polarization state of the acquired light. Create a first model in which the void layer and the membrane layer overlap, and a second model in which the layer related to the cover member, the void layer, and the membrane layer overlap,
Receiving a thickness dimension of a sample to be measured by the measuring device;
The sample analysis method according to claim 1, further comprising: selecting the first model and / or the second model as a model to be used for analysis according to the accepted thickness dimension. A first model in which the void layer and the membrane layer overlap; a second model in which the layer related to the cover member, the void layer, and the membrane layer overlap; a layer related to the ambient atmosphere of the cover member; a layer related to the cover member; Create a third model with overlapping membrane layers,
Receiving a thickness dimension of a sample to be measured by the measuring device;
When the sample to be measured by the measuring instrument has a translucent cover member, a model that uses at least one of the first model, the second model, and the third model for analysis according to the received thickness dimension The sample analysis method according to claim 1, further comprising: The optical characteristics of a sample in which a plurality of films stacked on a substrate are covered with a cover member at an interval are measured with a measuring instrument that irradiates polarized light, and based on the model corresponding to the sample and the measurement results of the measuring instrument A sample analysis method for analyzing the characteristics of each film layer of the sample ,
A step of placing on the stage of the translucent substrate of the sample one side and is bonded to one surface and the cover member of the translucent substrate and the lower side,
Irradiating the sample cover member with polarized light;
Obtaining light reflected from the sample;
And a step of measuring the polarization state of the acquired light. Create a first model in which the layers and film layers related to the substrate overlap, and a second model in which the layers related to the ambient atmosphere of the substrate, the layers related to the substrate, and the film layers overlap,
Receiving a thickness dimension of a sample to be measured by the measuring device;
When the sample to be measured by the measuring instrument has a translucent substrate, the step of selecting the first model and / or the second model as a model to be used for analysis according to the accepted thickness dimension is provided. 2. The sample analysis method described in 1. When multiple models to be used for analysis are selected, a step of performing fitting for each model to calculate a mean square error;
Select the model with the lowest mean square error value or the model with the lowest mean square error value that falls within the preset minimum to maximum film thickness range from multiple models. A model selection step and
The sample analysis method according to claim 2, wherein a value related to the model selected in the model selection step is used as an analysis result. Based on a model used for analysis, comprising a step of calculating an item equivalent to an item to be measured by the measuring instrument,
In this step, either the first calculation process corresponding to the interference fringes generated in the sample by light irradiation or the second calculation process not corresponding to the interference fringes is performed.
The sample analysis method according to claim 1, wherein the characteristic of the film is analyzed using the calculated result. Comparing the distance between the sample film and the cover member and the size of the reference distance,
The sample analysis method according to claim 7, wherein the second calculation process is performed when the interval distance is larger than the reference distance.   The sample analysis method according to claim 8, further comprising a step of changing the value of the reference distance. Measuring device having irradiation means for irradiating polarized light to a sample covered with a film laminated on a light-transmitting substrate with a gap, and means for measuring the polarization state of light by obtaining light reflected by the sample A sample analysis apparatus comprising: a model corresponding to the sample; and a means for analyzing the characteristics of the sample based on the measurement result of the measuring instrument
Means for storing a plurality of models of different structures;
Means for receiving a thickness dimension that is a sum of a thickness of the light-transmitting substrate and a thickness of the cover member of a sample in which one surface of the light-transmitting substrate and one surface of the cover member are bonded together ;
Depending on the thickness accepted, the sample analyzing apparatus, characterized in that it comprises a means for selecting a model used in the analysis from the plurality of models. Measuring device having irradiation means for irradiating polarized light to a sample covered with a film laminated on a light-transmitting substrate with a gap, and means for measuring the polarization state of light by obtaining light reflected by the sample A sample analysis apparatus comprising: a model corresponding to the sample; and an analysis means for analyzing the characteristics of the sample based on the measurement result of the measuring instrument,
Based on the model used for the analysis, equipped with a calculation means for calculating an item equivalent to the item measured by the measuring instrument,
The calculation means is configured to perform either a first calculation process corresponding to an interference fringe generated in the sample by light irradiation or a second calculation process not corresponding to the interference fringe,
The analysis means analyzes the characteristics of the film using the result calculated by the calculation means ,
Means for receiving an interval distance from a film of a sample in which one surface of the translucent substrate and one surface of the cover member are bonded to each other; and
Means for comparing the received distance and reference distance, and
The sample analysis apparatus in which the calculation means performs the second calculation process when the interval distance is larger than the reference distance . The optical characteristics of a sample in which a plurality of films laminated on a light-transmitting substrate are covered with a cover member at an interval are measured with a measuring instrument that emits polarized light, and the model corresponding to the sample and the measurement of the measuring instrument are measured. A sample analysis method for analyzing characteristics of each film layer of a sample based on a result,
Irradiating polarized light to the light-transmitting substrate of the sample;
Obtaining light reflected from the sample;
Measuring the polarization state of the acquired light;
Creating a first model in which the void layer and the membrane layer overlap, and a second model in which the layer related to the cover member, the void layer, and the membrane layer overlap;
Receiving a thickness dimension of a sample to be measured by the measuring device;
Selecting the first model and / or the second model as a model to be used for analysis according to the accepted thickness dimension;
A sample analysis method comprising: The optical characteristics of a sample in which a plurality of films stacked on a substrate are covered with a cover member at an interval are measured with a measuring instrument that irradiates polarized light, and based on the model corresponding to the sample and the measurement results of the measuring instrument A sample analysis method for analyzing the characteristics of each film layer of the sample,
Irradiating the sample cover member with polarized light;
Obtaining light reflected from the sample;
Measuring the polarization state of the acquired light;
Creating a first model in which a layer and a film layer related to the substrate overlap, and a second model in which a layer related to the ambient atmosphere of the substrate, a layer related to the substrate, and a film layer overlap;
Receiving a thickness dimension of a sample to be measured by the measuring device;
When the sample to be measured by the measuring instrument has a translucent substrate, selecting the first model and / or the second model as a model to be used for analysis according to the received thickness dimension;
A sample analysis method comprising:

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