JP2013036872A - Raman spectrometer and raman spectroscopic measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Raman spectrometer and a measuring method in which Raman scattering light and Rayleigh scattered light can be detected by the same one detection optical system and further a device function component is canceled to obtain accurate film component depth direction distribution.SOLUTION: A Raman spectrometer comprises a laser light source, a microscopic optical system including a separation optical element which receives Rayleigh scattered light and scattering light from a sample and an objective lens which is an immersion lens, a filter optical element through which light of a specific wavelength in light via the separation optical element is transmitted, spectrometric means which analyzes the light transmitted through the filter optical element, and photodetection means which detects an intensity of the analyzed light. The filter optical element includes arithmetic means which is provided to select either to guide a part of the Rayleigh scattered light from the sample to the photodetection means so as to measure the Rayleigh scattered light or to cut off the Rayleigh scattered light from the sample and to guide the scattering light to the photodetection means, and is capable of performing deconvolution processing for canceling a device function component from a depth direction component profile of the received scattering light.

Description

  The present invention relates to a Raman spectroscopic measurement apparatus and a Raman spectroscopic measurement method, and in particular, receives Rayleigh light from a multi-layer transparent film sample interface and detects Raman scattered light generated when the sample is irradiated with light. The present invention relates to a Raman spectrometer and a measurement method.

  In recent years, as the speed, size, and colorization of image forming apparatuses are rapidly progressing, the trend of electrophotographic photosensitive member development is toward the addition of high functionality to devices. From the viewpoint of high sensitivity and high durability, There is a need for structural analysis of electrophotographic photoreceptor films at micron size.

Conventional methods for analyzing the depth direction of general materials have conventionally been X-ray microanalysis (EPMA), x-ray photoelectron spectroscopy (XPS), 2 Secondary ion mass spectroscopy (SIMS), Rutherford backscattering (RBS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and the like have been used.
Here, when analysis is performed in the depth direction from the surface of a film having a thickness of 5 to 40 μm in an electrophotographic photosensitive member, there are limited methods that can be applied under the condition that sample preparation is not required, and confocal laser fluorescence method, confocal method Examples include measurement methods such as laser Raman spectroscopy. Among these, confocal laser Raman spectroscopy and apparatus, which are a kind of scanning probe microscope technique, have been used because of the wide range of application to materials.

By the way, in the optical microscope observation, the light uniformly irradiated on the sample is collected by a lens and observed. When performing analysis in the depth direction of a light-transmitting film sample with a thickness using a Raman spectroscopic measurement system combined with a normal optical microscope optical system, the Raman scattered light from the non-focal point overlaps the Raman scattered light on the focal plane. End up. As a result, the extracted information has a blur that includes information in the vicinity of the focal position and non-focal point at the same time, and this has caused a reduction in the spatial resolution of the Raman spectrometer.
In order to solve such a problem, a confocal laser Raman spectroscopic measurement apparatus using a confocal microscopic optical system has been developed and attracts attention as an influential measurement technique for depth measurement.

  In a confocal microscopic optical system, when an object is irradiated with Rayleigh light or Raman scattered light (laser or other monochromatic light from a focal point), scattered light having a wavelength different from that of the incident light is observed. Here, the wavelength is equal to the incident light. Is called Rayleigh scattered light (elastically scattered light), while scattered light having a wavelength different from that of incident light (inelastically scattered light) is called Raman scattered light. In order to detect only the light from the focal point of the sample by transmitting it through a lens and a pinhole arranged so as to be optically conjugate with the focal plane of the objective lens. Spatial resolution in the direction is obtained. By moving the sample position in the depth direction of the film in this state, a depth profile can be obtained.

The Raman scattered light observed with respect to the incident light is specific to the substance, and the substance or component can be specified by examining the spectrum of the scattered light. The confocal optical system can measure the component profile in the depth direction of the film in units of microns. In recent years, a film structure analysis has been performed using these two functions.
However, in a general dry objective lens, the beam diameter expands due to the aberration caused by the refractive index difference of the objective lens-medium (air) -film in the film, and the excitation light energy and spatial resolution in the film with respect to the surface. There was also a problem of lowering.

  As a method for solving this problem, there is a so-called index (refractive index) matching technique that suppresses the expansion of the beam diameter and suppresses the decrease in excitation energy and spatial resolution in the film. This solves most of the problems described above. However, when the film thickness of the laminated film is as thin as 5 μm or less, or when the film component has a steep concentration change, the spatial resolution is lowered because a component called a device function is additionally superimposed on the observed waveform, In particular, there is a problem that it is generally impossible to evaluate the migration of the film component at the film interface in the depth direction of the film of the thin film laminated sample with high accuracy.

A general microscopic Raman apparatus that does not use a confocal microscopic optical system has a spatial resolution of several tens of μm and can perform nondestructive / noncontact measurement under atmospheric pressure.
On the other hand, the confocal laser Raman spectroscopic measurement apparatus has a high spatial resolution (Min: 0.5 to 2 μm), and is characterized by being capable of analyzing the chemical structure, crystallinity, orientation, and the like of a minute part. . However, in the confocal laser Raman spectroscopic measurement device, when a device function generally called a slit function or a PSF (Point Spread Function) is superimposed, the blur component of the film component at the film interface may be 7 to 10 μm depending on the case. Shows the extent of expansion.
In a linear system, the observed waveform is given by convolution (convolution) integration between the true waveform and a device function representing the characteristics of the system.

The PSF is a function representing the response of the optical system to the point light source, and more generally called an impulse response. For example, a sharp spectrum in a spectroscope optical system and a point light source in an image forming optical system are input impulses, and spectral broadening and blurring of point images are impulse responses. The slit function and PSF are generally called device functions as common terms.
When handling a waveform represented by a function of the spatial position, the spread other than the spatial resolution in the depth direction is also an element of the device function, and apparently has a shape having a width before and after the observed waveform.

Commercially available microscopic Raman spectroscopes use index (refractive index) matching technology that suppresses the decrease in spatial resolution caused by the difference in refractive index, Rayleigh light receiving technology that acquires film interface information, and deconvolution that removes the blur caused by the instrument function. To date, no device that can evaluate the migration of film components at the film interface in the depth direction of the sample film using the technology has been put on the market. Deconvolution is a technique for removing blur such as a spectrum caused by a device function when an observed spectrum or signal is given by a convolution (convolution integration) of a true spectrum or signal and the device function.
The output waveform from the measuring instrument and the input waveform (a true waveform that is not distorted) are connected by a linear integration operation called convolution (convolution) integration with a device function. Therefore, if the device function is known, a true waveform can be obtained from the observed waveform.

  In other words, various problems when measuring the migration of (arbitrary) film components to other layers in a laminated film with a microscopic Raman spectroscopic device or a confocal laser Raman spectroscopic device that forms microspots, especially the occurrence of aberrations in the film. The idea of solving non-destructive and rapid migration of film components at the film interface in a state where the information on the film interface is given by Rayleigh light is solved. There was no.

In the configuration of a conventional general confocal laser Raman spectroscopic measurement apparatus, for example, as shown in FIG. 1, a laser beam emitted from a laser light source 20 is condensed by a condenser lens 21, and the focal point by this condenser lens is increased. The first pinhole 22 is positioned on the first pinhole 22, and the diffused light beam transmitted through the pinhole is guided to the second condenser lens 24 via the separation optical element 23 serving as a dichroic mirror. Thus, the light beam is configured to be condensed on the sample 1.
Thereafter, the light beam collected on the sample 1 is reflected from the sample 1 including Raman scattered light, returns to the dichroic mirror 23 through the second condensing lens 24 while being converged. The light that has returned to the dichroic mirror 23 is guided only to the Raman scattering light to the detection unit 26 side due to the characteristics of the dichroic mirror.
Further, the reflected light is once condensed before passing through the dichroic mirror 23 and being guided to the detection unit 26, and the second pinhole 25 is installed at the condensing position.
The first pinhole and the second pinhole are in conjugate positions with respect to the dichroic mirror (positions with the dichroic mirror as the axis of symmetry).
In the following Non-Patent Document 1, these methods are proposed.

Thus, in the configuration of the conventional general confocal laser Raman spectroscopic measurement device, the spatial resolution is lowered due to the difference in refractive index between the lens, the medium (air), and the film, and the spatial resolution is lowered due to the superposition of the device functions. Since the information on the film interface could not be obtained, it was not possible to evaluate the position of the laminated film interface and the migration of film components at the film interface with high resolution.
In this case, since the Rayleigh light is removed by the dichroic mirror, it is impossible to detect and use the Rayleigh light having the interface information in the light-transmitting film sample as the sample, At this stage, it is impossible to acquire interface position information inside the film, which is a migration determination index.

  As another known technique, the following Patent Document 1 discloses a deconvolution analysis device that performs a deconvolution process on a depth direction analysis result by a surface analysis method using sputtering. ), A means for deriving the true depth distribution from the depth direction distribution is presented, the interface information of the film cannot be acquired, and the migration of the film component having a steep slope cannot be evaluated. (See Patent Document 1)

  Patent Document 2 below discloses the idea of acquiring Rayleigh light and depth direction film component profiles as film interface information. However, in Patent Document 2, device functions that overlap the depth direction component profiles are disclosed. Since it cannot be removed, as shown in FIG. 8 of the Patent Document 2, a blur component (expansion of the skirt) due to the device function remains, so that it is difficult to determine the migration of the film component.

  With the above-described conventionally known technique, it is difficult to accurately extract Rayleigh light, that is, interface information essential for analysis of a light-transmitting film sample formed on a substrate in a Raman spectroscopic measurement apparatus. There is a problem that it is difficult to evaluate “migration of film components at the film interface in the depth direction” in which device functions that are blur components such as an image spreading function are superimposed.

  The present invention has been made in consideration of the above-described circumstances, and is weak Raman scattered light for providing interface information necessary for depth direction analysis of a light-transmitting film sample formed on the sample. Is measured by a detector, and Rayleigh light including accurate interface reflection information is detected by the same single detection optical system, and is associated with a spectral data profile for each depth position by Raman spectroscopy, and the depth direction of the film The device function component superimposed on the component is removed by deconvolution processing, and the accurate spectroscopic distribution of the film component is obtained, so that the Raman spectroscope that can evaluate "migration of the film component at the film interface in the depth direction" can be evaluated. And to provide a Raman spectroscopy.

In order to solve the above problems, a Raman spectroscopic device according to the present invention includes a laser light source that emits laser light, a separation optical element that receives Rayleigh light and scattered light from a sample irradiated with the laser light, and an oil A microscopic optical system having an objective lens that is an immersion lens, a filter optical element that transmits light of a specific wavelength in the light that has passed through the separation optical element, and a spectroscopic unit that splits light that has passed through the filter optical element. A light detecting means for detecting the intensity of the light split by the spectroscopic means, and the filter optical element guides a part of the Rayleigh light from the sample to the light detecting means in a measurable manner, and The depth direction component profile of the scattered light received by the light detection means is provided so as to be selectable to either block Rayleigh light from the sample and guide the scattered light to the light detection means. It characterized by having a deconvolution possible computing means for removing instrumental function components from Le.
In order to solve the above problems, the Raman spectroscopic measurement method according to the present invention includes a laser light source that irradiates laser light, and a separation optical element that receives Rayleigh light and scattered light from a sample irradiated with the laser light. And a microscopic optical system having an objective lens that is an oil immersion lens, a filter optical element that transmits light of a specific wavelength in the light that has passed through the separation optical element, and spectrally separates the light that has passed through the filter optical element Raman spectroscopic measurement apparatus having spectroscopic means, photodetecting means for detecting the intensity of light split by the spectroscopic means, and arithmetic means capable of deconvolution processing for removing apparatus function components from scattered light received by the photodetecting means Raman spectroscopic measurement method, wherein the filter optical element is adjusted to guide a part of Rayleigh light from the sample to the light detection means, and the depth of the sample is measured. Which detects the reflected light intensity of Rayleigh light at the film interface in the direction and associates it with the spectral data profile for each depth position by Raman spectroscopy, and the film that can be extracted from the spectral data file for each depth position obtained by Raman spectroscopy A step of performing deconvolution on the depth direction component profile of the film, and a step of evaluating the migration of the film component at the film interface as a result of analysis of the Rayleigh light and the depth direction component profile of the film. .

  According to the present invention, acquisition of film interface position information under a high spatial resolution condition from a light-transmitting film sample formed on a substrate, and acquisition of an estimated true component distribution profile in the depth direction Therefore, it is possible to provide a Raman spectroscopic device and a Raman spectroscopic measurement method capable of evaluating migration of a film component at the interface of the film component.

It is the structure schematic of the conventional common confocal laser Raman spectroscopy measuring apparatus. It is the schematic which shows the structure of the light transmissive film | membrane of the photoreceptor used as a test object in this invention. (A) It is the schematic which shows the structure in one Embodiment of the laser Raman spectrometer which concerns on this invention. (B) It is the schematic which shows the structure in other embodiment of the laser Raman spectrometry apparatus which concerns on this invention. It is an example of the characteristic figure of the dichroic mirror which has the characteristic which reflects the wavelength range of a laser light source at the time of using 488 nm wavelength light as excitation laser light. It is a graph which shows the optical characteristic of a notch filter. It is a graph which shows the optical characteristic of an edge filter. It is a graph which shows the relationship between Rayleigh reflection intensity and a depth direction position, and represents the interface information (Rayleigh light leakage light profile: interface reflection intensity distribution map) of the film | membrane which is a test object. It is a graph which shows the relationship between Raman intensity | strength and Rayleigh reflection intensity, and the position of a depth direction, and represents the interface information and film | membrane component profile (concentration profile in the film | membrane of the electric charge transport layer 5) of the film | membrane which is a subject. It is a graph which shows the spectral data profile of the Raman scattered light for every position of the depth direction of the sample for PSF (apparatus function) acquisition. It is the graph which displayed the deconvolution result superimposed on FIG.

The Raman spectroscopic device according to the present invention includes a laser light source 30 that emits laser light, a separation optical element 33 that receives Rayleigh light and scattered light from the sample 1 irradiated with the laser light, and an oil immersion lens. A microscopic optical system having an objective lens 34, a filter optical element 37 that transmits light having a specific wavelength in the light that has passed through the separation optical element 33, and a spectroscopic unit that splits light that has passed through the filter optical element 37. And a light detecting means 36 for detecting the intensity of the light split by the spectroscopic means, and the filter optical element 37 is capable of measuring a part of one Rayleigh light from the sample. The light scattering means received by the light detection means 36 is provided so that it can be selected from either guiding or scattering the Rayleigh light from the sample 1 and guiding the scattered light to the light detection means 36. It characterized by having a deconvolution possible operation means 38 for removing the device function component from the depth direction component profile of light.
The Raman spectroscopic measurement method according to the present invention includes a laser light source 30 that irradiates laser light, a separation optical element 33 that receives Rayleigh light and scattered light from the sample 1 irradiated with the laser light, and oil immersion. A microscopic optical system having an objective lens 34 as a lens, a filter optical element 37 that transmits light of a specific wavelength in the light that has passed through the separation optical element 33, and the light that has passed through the filter optical element 37 is dispersed. Raman having spectroscopic means, light detecting means 36 for detecting the intensity of the light split by the spectroscopic means, and arithmetic means 38 capable of deconvolution processing for removing apparatus function components from scattered light received by the light detecting means 36 In the Raman spectroscopic measurement method of the spectroscopic measurement device, the filter optical element 37 is adjusted so that a part of the Rayleigh light from the sample is extracted from the light detection means 3. And detecting the reflected light intensity of Rayleigh light at the film interface in the depth direction of the sample 1 and associating it with the spectral data profile for each depth position by Raman spectroscopy, and for each depth position obtained by Raman spectroscopy. Deconvolution of the depth component profile of the film that can be extracted from the spectral data file and evaluation of migration of film components at the film interface as a result of Rayleigh light and film depth component profile analysis It is characterized by having.
Next, with reference to the drawings, the Raman spectroscopic measurement apparatus and the Raman spectroscopic measurement method of the present invention will be described in detail by embodiments.

Typical examples of the structure of the light-transmitting film of the photoconductor that is the subject in the present invention are listed below.
FIG. 2 is a diagram showing a layer structure of a photosensitive drum in which an intermediate layer 3, a charge generation layer 4, a charge transport layer 5, and a surface layer 6 are sequentially formed on an aluminum drum 2 serving as a cylindrical substrate. The charge generation layer 4, the charge transport layer 5, and the surface layer 6 form a photosensitive layer. The intermediate layer 3, the charge generation layer 4, the charge transport layer 5, and the surface layer 6 form the film sample 1.

In FIG. 2, the intermediate layer 3 has a function as a binder for adhering and fixing the photosensitive layer to a conductive cylindrical substrate (hereinafter also referred to simply as a substrate), and suppresses adverse effects such as charging unevenness. Contains “fine particles of pigment”.
In FIG. 2, the charge generation layer 4 is a layer that generates “positive and negative charge pairs” by light irradiation of a specific wavelength, and the charge transport layer 5 and the surface layer 6 are positive and negative generated in the charge generation layer 4. Among the negative charges, this is a layer having a function of transporting charges of a predetermined polarity to the photosensitive layer surface (that is, the surface layer 6 surface).
Further, the surface layer 6 also has a function of preventing the photosensitive member from being deteriorated due to physical contact and abrasion within the actual apparatus, and the characteristics of the photosensitive member being deteriorated.

The film thicknesses of the intermediate layer 3, the charge generation layer 4, the charge transport layer 5, and the surface layer 6 are preferably 2 to 6 μm, 1 μm or less, 15 to 35 μm, and 3 to 10 μm, respectively. The thickness is about 18 to 46 μm.
The layer thickness of the intermediate layer 3 is generally in the range of 2 to 6 μm as described above. However, in order to achieve a satisfactory function as a binder and a light shielding effect on the conductive substrate, The thickness of the layer 3 is preferably 3 μm or more.

Among these, the Raman spectroscopic measurement apparatus or the Raman spectroscopic measurement method according to the present embodiment is used, for example, by looking at the component profiles in the charge transport layer 5 and the surface layer 6 that are light-transmitting films, and the charge transport layer 5 component is the surface layer. There is a need to analyze whether it is migrating.
As Rayleigh light (reflected light intensity at the film interface in the depth direction), it is possible to receive reflected light from the surface of the surface layer 6, the surface of the charge transport layer 5, and the surface (interface) of the intermediate layer 3.

Next, the configuration of the Raman spectrometer according to the present invention will be described.
FIG. 3 is a schematic cross-sectional view showing a configuration example of a Raman spectrometer according to the present invention. FIG. 3A shows a part of Rayleigh light from the film sample 1 formed on the aluminum drum, which is guided to the detection unit 36 so as to be measurable together with the scattered light, and then from the depth direction component profile of the received scattered light. A configuration is shown that includes computing means 38 capable of deconvolution processing to remove device function components. FIG. 3B shows the apparatus based on the depth direction component profile of the received scattered light after blocking the Rayleigh light from the film sample 1 formed on the aluminum drum and guiding the Raman scattered light to the detector 36. A configuration including an arithmetic means 38 capable of performing deconvolution processing for removing function components is shown.

  As shown in FIG. 3, the Raman spectroscopic measurement apparatus according to the present invention includes a laser light source (laser light source 30) and Rayleigh light and scattering from a sample irradiated with laser light (film sample 1 formed on an aluminum drum). A separation optical element that receives light (dichroic mirror 33) and an objective lens (objective lens 34) that is an oil immersion lens, and emulsion oil (not shown) is filled between the oil immersion lens and the sample. And a filter optical element that transmits light of a specific wavelength in the light that has passed through the separation optical element (only the laser light blocking optical element 37 that is part of the filter optical element is shown in FIG. 3B). , A spectroscopic unit (not shown) that splits the light transmitted through the filter optical element, a light detection unit (detection unit 36) that detects the intensity of the split light, and the depth direction of the received scattered light Comprising a deconvolution possible computing means 38 from the distribution profile removing device function components.

  The microscope stage of the Raman spectroscopic measurement apparatus may be provided with a cylindrical sample grasping jig, a radial direction drive unit, and a Z-axis direction drive unit. In this case, a light-transmitting film sample is placed in the Z-axis direction. Spatial resolution is created by focusing incident light and detection light (Raman scattered light) with the objective lens while moving the microscope stage or moving the objective lens. In the microscope stage, a piezo element or a stepping motor moving mechanism is installed as a Z-axis direction drive unit, and scanning in the Z direction (thickness direction) of a light transmissive film sample is performed.

  In the case of a confocal laser Raman spectroscopic measurement device, a light-transmitting film sample formed on the sample is scanned in the optical axis direction by moving the microscope stage or objective lens in the Z direction of the microscope. Is possible. The spatial resolution of the optical system greatly depends on the NA (= Numerical Aperture) of the objective lens. In order to achieve high spatial resolution, an oil immersion lens is used during measurement.

  In FIG. 3, the laser light emitted from the laser light source 30 is laser light used for excitation in confocal laser Raman spectroscopy, and a wavelength that has no Raman absorption or fluorescence in the film to be detected and has Raman activity is selected. Generally, the light is dimmed using a combination of several ND filters.

The intensity of the laser beam to be used may be about 1 to 100 mW / cm ² at the emission port, and thereafter the intensity on the light-transmitting film sample 1 to be a sample is several nW / μm ² to several μW / μm ² . The adjustment may be made so that it is within the range.

  In general, the higher the intensity of the laser beam, the stronger the Raman scattered light intensity detected and the S / N ratio is improved. However, it is necessary to decide in consideration of sample destruction, fading, response to strong light, and the like. The determination of the laser light intensity condition is one of the most important items because the light-transmitting film sample has different absorption intensity and light resistance.

If the wavelength is short, the Raman scattering intensity increases in inverse proportion to the fourth power of the wavelength.
When an organic film is used as a target, the laser wavelength is preferably 480 nm or more when considering the optical damage of the target film and the generation of fluorescence in the film, which is not preferable for Raman measurement, and considering the Raman scattering intensity as described above. The shorter the wavelength, the better, and as a result of examination, it has been found that if the wavelength is 900 nm or less, suitable measurement can be performed.

  Further, on the exit side of the laser light source 30, a condensing lens 31 that condenses the laser light beam emitted from the laser light source 30, and a first pinhole 32 disposed on the focal point of the condensing lens 31, , Is provided.

  The dichroic mirror 33 used as the separation optical element is a mirror that separates light into two or more wavelength regions by a dielectric multilayer film. When the dichroic mirror has the characteristic of transmitting the reflected light of the Raman scattered light from the light-transmitting film sample formed on the sample through the wavelength range of the laser beam from the laser light source, conversely the Raman In some cases, the laser light source that is scattered light transmits a longer wavelength region and reflects the wavelength light of the laser light source.

  FIG. 4 is an example of a characteristic diagram of a dichroic mirror having a characteristic of reflecting a wavelength range of a laser light source when light having a wavelength of 488 nm is used as excitation laser light.

In the Raman spectroscopic measurement apparatus, the light component formed on the sample and the excitation light component (Rayleigh light) irradiated on the light-transmitting film sample formed on the sample using a dichroic mirror or the like that can split the wavelength. Raman scattered light generated from a permeable membrane sample is generally separated.
Ideally, the dichroic mirror used for separating the reflected light (Rayleigh light) and Raman scattered light of the pump laser light has a transmittance characteristic that changes binaryly at a specific wavelength. However, even if the actual transmittance characteristic changes relatively steeply, the transmittance does not become 0 or 1. For this reason, the light separated by the dichroic mirror includes not only Raman scattered light but also Rayleigh light.
Therefore, even when the dichroic mirror 33 is disposed, Rayleigh light leaks to the detection unit 36 side, but very strong Rayleigh light that saturates the detector of the detection unit 36 is incident on the detector. The detection unit 36 realizes light reception capable of detecting Rayleigh light.

  The objective lens 34 is a second condenser lens next to the condenser lens 31. That is, the focal point of the excitation laser beam is made coincident with the focal point of the objective lens 34, and the excitation laser beam is irradiated so as to be one point on the light-transmitting film sample 1 formed on the sample. In addition, a second pinhole 35 is placed at the back focal point of the objective lens 34 to efficiently cut Raman scattered light other than the focal point.

  In order to achieve both high optical system throughput and a small focused beam spot, the diameter of the laser beam applied to the objective lens 34 is set equal to the incident diameter of the objective lens 34.

  Further, the spatial resolution in the microscopic optical system greatly depends on the NA of the objective lens 34 and the confocal pinhole diameter. In the present invention, an oil immersion lens is used as the objective lens 34 during measurement in order to achieve high spatial resolution. . Further, the emulsion oil is filled between the objective lens 34 and the film sample 1 formed on the substrate, and the structure is an oil immersion lens + emulsion oil.

In the reflection type Raman spectroscopic measurement apparatus as shown in FIG. 3, excitation and detection are performed by the same objective lens 34.
Since the Raman scattered light from the depth other than the focal point is not focused at the position of the second pinhole 35, the interference light is efficiently cut (as shown in FIG. 3) Most of the reflected light on the broken line indicating the path is shielded by the second pinhole). However, in the film of the film sample 1 formed on the cylindrical substrate, the beam diameter expands due to the influence of chromatic aberration and spherical aberration due to the difference in refractive index. Therefore, it is necessary for measurement to suppress the spread.

  The configuration of “oil immersion lens + emulsion oil” is generally devised to fill the gap between the lens and the film with an oil having a refractive index equivalent to that of glass to eliminate the influence of air and lens refraction. That is, in a dry lens, the medium through which light passes from the lens to air and further to the target film changes and refraction (aberration) occurs. On the other hand, if the emulsion oil used in combination with the oil immersion objective lens (oil immersion lens) is 1.5 to 1.6, which has a refractive index close to that of the lens or film, the influence of light refraction can be eliminated. become. This is an effective means for increasing the spatial resolution in the film of the film sample 1 formed on the sample when the objective lens 34 having a large NA is used.

  The objective lens 34 preferably has a combination of an oil immersion lens and emulsion oil so that the NA (numerical aperture) is 1.2 or more. Unless NA is 1.2 or more, the spatial resolution in the calculation at the time of depth direction analysis cannot be ensured: 1 μm, and in particular, in the case of a thin film of 5 μm or less, clear film structure analysis is impossible.

The depth resolution is considered to maintain a constant resolution in the depth direction by using an index (refractive index) matching technique.
NA is an important value that determines the performance of the objective lens, and is a value related to the depth of focus (spatial resolution) and brightness. As NA increases, spatial resolution improves. It is also called NA (= Numerical Aperture) and is represented by the following equation. However, in general, for a commercially available objective lens, a single NA is described.

    NA = n · sinθ

(Where n is the refractive index of the medium (in this case, emulsion oil) between the target film and the objective lens 34 in the film sample 1, and θ is the angle formed by the optical axis and the light beam entering the outermost side of the objective lens 34). .)

  Regarding the refractive index of the emulsion oil, the manufacturer's measured value can be used, or the emulsion oil can be applied to the Si wafer with a spin coater and then measured with a spectroscopic ellipsometer. .

  In the above state, by scanning the focal position of the laser light from the laser light source 30 in the depth direction of the film sample 1 formed on the substrate, the light transmissive film sample 1 can be used for the microscope stage or the objective. By moving the lens in the Z direction, a clear Rayleigh light profile and Raman signal profile can be obtained in the depth direction for each step (thickness direction of the film sample), and high-resolution structure analysis in the depth direction becomes possible.

  However, if the sample has a Drum shape and the center of curvature radius of the sample and the laser optical axis do not match, it is difficult to obtain an accurate Rayleigh light profile that is the interface information of the film due to the influence of the curvature. Become.

  The microscopic optical system in the Raman spectroscopic measurement apparatus of the present invention is a confocal microscopic optical system including pinholes (first pinhole 32 and second pinhole 35) having a conjugate relationship with the focal plane on the object. Preferably there is. That is, the first pinhole 32 is provided between the condenser lens 31 and the dichroic mirror 33, and the second pinhole 35 is provided in front of the dichroic mirror 33 and the detection unit 36, so that two pinholes are provided. Are in confocal positions, each having a focal point. As a result, in the confocal microscopic optical system, Raman scattered light from other than the focal point is blocked by the pinhole, so unnecessary light from inside the film other than the focal point and Raman scattered light from inside the light-transmitting film sample are removed. Almost complete removal is possible, and excellent spatial resolution in the depth direction can be achieved.

  The Raman spectroscopic measurement apparatus of this embodiment can measure Raman scattered light and Rayleigh light with the same detection optical system.

  In the present invention, the filter optical element constituting the microscopic optical system guides a part of the Rayleigh light from the film sample 1 formed on the sample to the detection unit 36 so that it can be measured together with the scattered light, or is formed on the sample. It is possible to select whether to block Rayleigh light from the film sample 1 and guide scattered light to the detection unit 36.

  In the confocal microscopic optical system, the laser light is condensed in a narrow area by the objective lens 34 and irradiated onto the light-transmitting film sample 1 formed on the substrate, so that it is not comparable to ordinary spectroscopic measurement. It becomes high intensity excitation light. For this reason, even the Rayleigh light component leaking from the dichroic mirror 33 or the Rayleigh light component that has passed through one or more laser light blocking optical elements (filter optical elements) has an intensity comparable to the Raman scattered light.

  In the present invention, the dichroic mirror 33, or the dichroic mirror 33 and one or more laser light blocking optical elements are used to weaken the Rayleigh light component from the film sample 1 formed on the sample to a level that can be detected by the detection unit 36. Next, the Rayleigh light component is detected by the detection unit 36 so that interface information in the depth direction of the film that is the subject of the film sample 1 formed on the substrate can be acquired.

  In the microscopic optical system according to the present invention, the filter optical element is composed of one or a plurality of laser light blocking optical elements, and at least one of them is a laser light blocking optical element that blocks laser light equivalent to Rayleigh light ( It is preferable that the first laser light blocking optical element) is provided so as to be removable. Alternatively, at least one of the filter optical elements includes a laser beam blocking optical element (first laser beam blocking optical element) that blocks a laser beam equivalent to Rayleigh light and a transmittance with respect to a wavelength of the laser beam equivalent to Rayleigh light. It is preferable that a laser beam blocking optical element (second laser beam blocking optical element) having a raised height is provided so as to be interchangeable.

  In addition, the transmittance of the laser light blocking optical element that can be inserted and removed here, or the laser light blocking optical element that blocks laser light equivalent to Rayleigh light and the wavelength of the laser light equivalent to Rayleigh light has been increased. Of the laser light blocking optical elements that are interchangeably provided, a laser light blocking optical element (first laser light blocking optical element) that blocks laser light equivalent to Rayleigh light is shown in FIG. Is disposed between the dichroic mirror 33 and the second pinhole 35 (that is, before the spectroscope serving as the spectroscopic means). Examples of the laser light blocking optical element 37 include a notch filter and an edge filter, and are composed of a notch filter and / or an edge filter.

  Among these, the notch filter is one of laser light blocking optical elements used for removing Rayleigh light, and is a filter using a dielectric multilayer film. FIG. 5 shows the optical characteristics of the notch filter. As illustrated in FIG. 5, the notch filter is configured not to transmit only a specific wavelength. When the dielectric multilayer film is laminated and the film thickness is optimized, the notch filter has a wavelength of about 20 nm centered on the design wavelength. Light in the band can be removed.

  However, as can be seen from FIG. 5, the notch filter cannot remove 100% of Rayleigh light. By increasing the transmittance in the wavelength region that serves as a filter for this Rayleigh light, while preventing the very strong Rayleigh scattered light near the excitation laser light wavelength that saturates the detector of the detector 36 from entering the detector. It is possible to acquire Rayleigh light necessary for acquiring interface reflection information. Of these, a laser light blocking optical element that blocks laser light equivalent to Rayleigh light and a laser light blocking optical element that increases the transmittance with respect to the wavelength of laser light equivalent to Rayleigh light are provided interchangeably. This is a laser light blocking optical element with increased transmittance with respect to the wavelength of laser light equivalent to Rayleigh light.

  As the notch filter, a holographic notch filter produced by recording an interference pattern formed by two mutually coherent laser beams can be used.

  On the other hand, the characteristics of the edge filter are, for example, as shown in FIG. Here, an example in which the wavelength of the laser beam is 488 nm is shown, but the wavelength shorter than the wavelength of 490 nm can be completely removed. For example, in the case of using a dielectric multilayer film as an edge filter, if an optimum design is performed, the light on the shorter wavelength side is removed at an interval of about 30 nm before and after the wavelength separation design position, and on the contrary, Raman Light on the long wavelength side including scattered light can be transmitted. According to the present embodiment, even if an edge filter is inserted instead of the notch filter, the same effect as the notch filter can be obtained.

  In the present invention, the removable laser beam blocking optical element 37 is removed, or the laser beam blocking optical element 37 blocking the laser beam equivalent to Rayleigh light and the transmittance with respect to the wavelength of the laser beam equivalent to Rayleigh light are increased. From the film sample 1 formed on the substrate, the laser beam blocking optical element is replaced with a laser beam blocking optical element whose transmittance with respect to the wavelength of the laser beam equivalent to the Rayleigh light is increased. As shown in FIG. 7 to be described later, Rayleigh scattered light with sufficient sensitivity can be received, and the interface information of the film is extracted. I can do it.

  After that, the removable laser light blocking optical element 37 is returned to the optical path, or the laser light blocking optical element whose transmittance with respect to the wavelength of the laser light equivalent to Rayleigh light is increased blocks the laser light equivalent to the Rayleigh light. By replacing with the laser light blocking optical element 37 (FIG. 3B), Rayleigh light that becomes interference light at the time of Raman scattered light measurement can be completely removed from the light from the film sample 1 formed on the sample. This makes it possible to analyze the film structure by Raman spectroscopy with high sensitivity.

  As described above, according to the Raman spectrometer of this embodiment, it is possible to measure Raman scattered light and Rayleigh light with the same detection optical system. The transmittance of the laser light blocking optical element can be determined by, for example, a spectral reflectance measuring device.

The detection unit 36 includes a spectroscopic unit and a light detection unit.
Among these, as the spectroscopic means, a spectroscope that separates Raman scattered light by a diffraction grating can be cited. When there is a point (area) conjugate with the focal plane on the optical path immediately before entering the spectroscope, two perpendicular slits (cross slits) are placed in the XY plane of that portion, so that a set of slits is formed. It is possible to play the role of a confocal pinhole (second pinhole 35) in the confocal optical system, thereby generating a spatial resolution in the Z-axis direction. The cross slit also contributes to the wavelength resolution when acquiring the Raman spectrum.

  Examples of the light detection means include a multi-channel detector (for example, CCD: Charge Coupled Device) and a single channel detector (for example, APD: Avalanche Photodiode). The light that has passed through the second pinhole 35 enters the spectroscope configured in the detection unit 36 and is dispersed, and then is detected by this light detection means.

The computing means 38 capable of deconvolution processing performs data processing and display of film interface information (0 cm ⁻¹ : Rayleigh light profile) and film component profile (Raman scattered light) acquired by a light detection means such as a multi-channel detector. And is included as a waveform data processing unit in the PC as an algorithm (software) such as a maximum entropy method (MEM method) or a Richardson-Lucy (RL) method.

  In general, when the component concentration of molecular species in the film changes abruptly, if the device function is superimposed on the depth direction component profile, concentration blurring occurs at the concentration rising portion, and the component concentration profile is actually It will be different from the profile of component concentration. For this reason, in order to judge the migration of the film component, an incorrect result can be obtained unless the depth direction distribution is returned from the about distribution to the accurate distribution and then analyzed.

In order to improve this, a deconvolution process for removing a device function in the depth direction is performed as the above-mentioned calculation means.
The instrument function is generally unknown, but in the case of a dispersive spectrometer, the slit function is often the main cause, and the output observation waveform is deteriorated. At this time, if an apparatus function is obtained, a true signal source (a true waveform that is not distorted) can be estimated from a deteriorated observed waveform.

  That is, assuming that the measured depth direction distribution is I (z), the depth direction device function is g (z), and the true depth direction distribution is X (z), these three functions are as follows: It is expressed by the following formula.

I (z) = g (z) * X (z)
(Here, * indicates convolution integration.)

  Deconvolution is a method of estimating the true depth direction distribution X (z) from I (z) in consideration of this depth direction device function.

  Further, the microscope optical system (microscope unit) of the Raman spectroscopic measurement apparatus of the present invention is accompanied by a microscope stage, and the microscope stage is provided with a radial direction drive unit that can move in the radial direction of the sample and a sample thereon. A sample receiving part (gripping jig) for horizontally gripping may be installed, and a gripping jig or objective lens on which a light-transmitting film sample 1 formed on the sample in the Z-axis (film depth) direction is mounted. A depth profile is created by converging incident light and detection light (Raman scattered light) with the objective lens 34 while moving. The microscope stage is provided with a piezo element or a stepping motor moving mechanism so that the light transmissive film sample 1 can be scanned in the Z direction (thickness direction, optical axis direction).

  The migration measurement with respect to the surface layer of the charge transport layer of the target film in the film sample 1 formed on the substrate by the Raman spectrometer of the present invention having the above-described configuration is performed as follows.

(1) Extraction of film interface information The Raman spectroscopic measurement apparatus is configured as shown in FIG. 3 (a), and a laser beam emitted from a laser light source 30 and diffused through a condenser lens 31 and a first pinhole 32 is converted into a dichroic mirror. It is led to an oil immersion lens (objective lens 34) through 33, and this oil immersion lens allows the luminous flux to pass through the emulsion oil and to be condensed on the light-transmitting film sample 1 formed on the substrate. Next, the light beam collected on the film sample 1 formed on the substrate is reflected as light including Raman scattered light from the film sample 1 formed on the substrate, and is used as an emulsion oil, an oil immersion objective lens (objective). It returns to the dichroic mirror 33 through the lens 34) while focusing. The light returning to the dichroic mirror 33 is such that part of Rayleigh light and Raman scattered light (hereinafter collectively referred to as light) are directed toward the detection unit 36 due to the characteristics of the dichroic mirror.

  Further, this light is once condensed before being guided to the detection unit 36, and a laser light blocking optical element 37 that can be inserted and removed is removed, or a laser light blocking optical element that blocks laser light equivalent to Rayleigh light. Laser having an increased transmittance with respect to the wavelength of the laser beam equivalent to the Rayleigh light among the components 37 and the laser beam blocking optical element having an increased transmittance with respect to the wavelength of the laser beam equivalent to the Rayleigh light. The filter optical element having the configuration replaced with the light blocking optical element transmits a part of the Rayleigh light weakened to a level that can be measured by the detection unit 36 along with the Raman scattered light, and is further disposed at the condensing position. Then, the light is guided to the detection unit 36 and then incident on the spectroscope configured in the detection unit 36 and dispersed, and then the intensity of the Rayleigh light is detected by the detector. It becomes so that.

  In this state, the microscope stage or the objective lens on which the light-transmitting film sample 1 formed on the substrate is placed is scanned in the Z-axis direction by a piezo drive or a stepping motor moving mechanism as necessary. Detection is performed at a predetermined position in the Z-axis direction of the target film of the film sample 1 formed in the above. That is, the light intensity profile having the same wavelength as the laser excitation light is measured by the detector of the detection unit 36, and interface information in the depth direction in the film is extracted.

Thereby, it is possible to confirm a change in the light amount of Rayleigh light (0 cm ⁻¹ ) serving as interface reflection position information, and to specify the position of the interface of the film in the optical axis direction from the position where the light amount reaches a peak. For example, the interface information of the film as an object as shown in FIG. 7 can be acquired. Here, three reflection intensity peaks are observed, and each peak position is represented by the surface layer surface (emulsion of the target film). (Interface with oil), surface layer / charge transport layer interface, and interface with the lower layer (intermediate layer surface).

However, this profile is also distorted by the influence of the dynamic characteristics of the measuring instrument, that is, the device function.
In this case, the refractive index difference between the film and the medium (for example, emulsion oil in the case of using an oil immersion lens) is important in order to obtain Rayleigh light as interface reflection from the film interface. In order to secure the Rayleigh light, it has been found from the following formula (1) that the reflectance at the interface: R needs to be 0.1% or more.

Reflectivity R = ((N−N ₁ ) ² + κ ² ) / (N + N ₁ ) ² + κ ² ) (1)
N: Refractive index of the film to be measured
N ₁ : refractive index of the medium
κ: extinction coefficient of the film to be measured

  In general, if the difference in refractive index increases, it becomes easier to ensure interface reflection. In that case, the effect of aberration due to the difference in refractive index between the lens, medium, and film induces a decrease in spatial resolution and energy density. Become. For this reason, it is preferable to use an emulsion oil having a refractive index difference of −0.2 to −0.1, which is determined from the refractive index of the target film, for measurement.

(2) Structural Analysis of Film Next, the Raman spectroscopic measurement apparatus is configured as shown in FIG. 3B, and the laser light beam emitted from the laser light source 30 and diffused through the condenser lens 31 and the first pinhole 32 is dichroic. It is guided to an oil immersion lens (objective lens 34) through a mirror 33, and this oil immersion lens (objective lens 34) allows the luminous flux to pass through the emulsion oil and onto the light-transmitting film sample 1 formed on the substrate. Collect light. Next, the light beam collected on the film sample 1 is reflected as light containing Raman scattered light from the film sample 1, passes through emulsion oil and an oil immersion lens (objective lens 34), and converges on the dichroic mirror 33. Return. The light returning to the dichroic mirror 33 is such that part of Rayleigh light and Raman scattered light (hereinafter collectively referred to as light) are directed toward the detection unit 36 due to the characteristics of the dichroic mirror.

  Further, this light is once condensed before being guided to the detection unit 36, and a laser light blocking optical element 37 that can be inserted and removed is returned to the optical path, or a laser light blocking that blocks a laser beam equivalent to Rayleigh light. Laser light blocking optics for blocking laser light equivalent to Rayleigh light among optical elements 37 and a laser light blocking optical element having increased transmittance with respect to the wavelength of laser light equivalent to Rayleigh light. The filter optical element having the configuration replaced with the element 37 is a second optical element that is selectively transmitted through only the light having a wavelength band that matches the Raman scattered light to be detected after the Rayleigh light is completely excluded. After passing through the pinhole 35, guided to the detection unit 36, and then incident on and dispersed in the spectroscope configured in the detection unit 36, the intensity of Raman scattered light in a predetermined wavelength band by the detector So it is detected.

  In such a state, the microscope sample or the objective lens on which the light-transmitting film sample 1 formed on the substrate is mounted is scanned in the Z-axis direction by a piezo drive or a stepping motor moving mechanism as necessary, thereby the film sample. The detection of the Raman spectrum in the Z-axis direction of one target film is performed.

  Finally, using the detected Raman spectrum and the interface information of the previously extracted film, the peak value of the Raman band of any film component is plotted for each position in the depth direction, and the depth determined by Raman spectroscopy. A spectral data profile of the film component for each position in the direction is obtained.

  Through the above processing, it is possible to acquire the film interface position information and the film component distribution profile under a high spatial resolution condition from the light-transmitting film sample formed on the substrate.

(3) Deconvolution process In order to remove the instrument function of this measurement system from the spectral data profile of the film component at each depth position by Raman spectroscopy in this case, the Raman function is used to remove the instrument function. First, the PSF in the spectroscopic measurement apparatus is acquired.

A thin film sample of the same component as the charge transport layer is produced with a thickness less than the desired resolution (1 μm or less), held by a microscope stage, and the microscope stage or objective lens on which this thin film sample is placed is Z as required. A spectral data profile of Raman scattered light for each position in the depth direction of the PSF acquisition sample is obtained with the configuration of “oil immersion lens + emulsion oil” by scanning in the axial direction by piezo driving. (Fig. 9)
This is the PSF (apparatus function) of the component profile of the film for each depth direction by Raman spectroscopy.
In this case, the device function is also superimposed on the Rayleigh light profile that is the interface information of the film. However, since the interface coordinates can be accurately specified at the peak position of the reflection intensity, there is no need to perform deconvolution processing. good.
After that, deconvolution processing is performed using the component profile of the film at each depth position by Raman spectroscopy, which is the observed waveform, and the PSF, which is an instrument function, and the true component profile of the film at each depth position is estimated by Raman spectroscopy. To do.

  Since the above-described deconvolution analysis processing is generally performed in Fourier space, it is desirable that the distance between data points constituting the depth direction distribution is equal and the number of data points is a power of two.

(4) Migration evaluation The film's true component profile for each depth position obtained by Raman spectroscopy is compared with the film interface position information, and the film component, for example, charge, is measured from the rising position of the film component with the device function removed. Judge the migration of the transport layer to the surface layer.

  Examples of the present invention will be described below.

Example 1
Migration evaluation was performed on the surface layer of the charge generation layer of one sample of the film sample formed on the cylindrical substrate under the following conditions.

(1) Film sample 1: In FIG. 2, a film having a thickness of 3.5 μm having a structure in which particles and fine particles are dispersed in a binder resin as an intermediate layer 3 on an aluminum drum 2 serving as a cylindrical substrate of φ40 mm. After coating, and further forming a layer mainly composed of a binder resin and a charge generation material as a layer for generating a “positive and negative charge pair” by irradiation with light of a specific wavelength as the charge generation layer 4, the light transmission In this case, a charge transport layer 5 having a film thickness of 22 μm and a surface layer 6 having a film thickness of 2.5 μm are formed by dispersing any kind of components as a conductive film.

(2) Raman spectrometer: Configuration shown in FIG. 3 <Detailed configuration of device>
Laser light source 30: laser light wavelength = 488 nm
Objective lens 34: Oil immersion objective lens (OLYMPUS MPlan Apo 100 × NA = 1.4 (by filling emulsion oil with a refractive index of 1.516 between the target film and the objective lens 34), refractive index of 1.525 )
Emulsion oil: refractive index 1.516
Laser light blocking optical element 37; notch filter having the characteristics shown in FIG. 5 (function of cutting a wavelength of 488 nm)

  The refractive index of the target film is obtained by coating the target film on a Si wafer and measuring the complex refractive index (refractive index, extinction coefficient) with a spectroscopic ellipsometer (manufactured by JA Woollam, WVASE 32). It was. For the refractive index of the emulsion oil, the manufacturer's measured value (data attached to the product) was used as it was. The transmittance of the notch filter was confirmed by measuring the transmittance value with a spectral transmittance measuring device (Matsushita Techno Trading F20 device).

(3) Measurement procedure First, a film sample in which the charge transport layer 5 and the surface layer 6 are formed on a cylindrical substrate is placed on a sample gripping jig not shown in FIG. Thereafter, the center of curvature of the sample is aligned with the laser optical axis.

  Next, as shown in FIG. 3A, the notch filter is removed, and light transmission formed on a φ40 mm aluminum drum that becomes a cylindrical base by condensing the laser excitation light beam with the objective lens 34. A portion of the Rayleigh light from the film sample 1 formed on a φ40 mm aluminum drum serving as a cylindrical substrate is guided to the detector of the detector 36 and scanned in the depth direction. As a result, a “Rayleigh light leakage light profile (interfacial reflection intensity distribution diagram)” was obtained. (Fig. 7)

  Next, as shown in FIG. 3 (b), the light is formed on a φ40 mm aluminum drum having a configuration in which the notch filter is attached, and the light beam of the laser excitation light is condensed by the objective lens 34 to be a cylindrical base. The detection unit 36 emits Raman scattered light in a predetermined wavelength band obtained by irradiating one point of the transparent film sample 1 and removing Rayleigh light from the light from the film sample 1 formed on the φ40 mm aluminum drum serving as a cylindrical substrate. The charge transport layer 5 is obtained by leading to a detector, scanning in the depth direction, obtaining a Raman spectrum in the depth direction, and chasing the characteristic Raman band peak of any film component of the charge transport layer 5. The “in-film concentration profile” was obtained.

  Next, the peak value of the Raman band of an arbitrary film component of the charge transport layer 5 is obtained by combining the “Rayleigh light leakage light profile (interfacial reflection intensity distribution diagram)” and “the film component profile at each depth position”. Plotting is performed for each position in the depth direction, and a spectral data profile of the number of powers of two powers for each position in the depth direction is obtained.

  In FIG. 8, the measurement result of Example 1 obtained by the above measurement procedure is shown. FIG. 8 shows the Raman of the charge transport layer 5 that is a power of two data points and is provided with film interface information (Rayleigh light profile) in a light-transmitting film sample 1 formed on a φ40 mm aluminum drum serving as a cylindrical substrate. This is a film depth direction component profile (observation waveform: in-film concentration profile) that can be extracted from a spectral data profile at each depth position by spectroscopy, and an arbitrary one type of component is dispersed in the charge transport layer 5 It is.

  Thereafter, a smoothing process for reducing high-frequency noise components in advance is performed on the depth direction component profile (observation waveform) of the film that can be extracted from the acquired spectral data profile for each depth position by Raman spectroscopy in the PC. .

  Thereafter, a spectral data profile for each position in the depth direction was obtained from a 1 μm thick thin film of the same component as the charge transport layer 5, and PSF was obtained (FIG. 9).

Furthermore, the deconvolution process was implemented by the deconvolution algorithm (RL method) programmed in PC used as the calculation means in which a deconvolution process is possible. From the interface between the surface layer 6 and the charge transport layer 5, the charge transport layer 5 component migrated to the surface layer 6 side. (FIG. 10 shows the deconvolution result.)
Charge transport with a very steep slope at the interface by performing deconvolution processing (deconvolution result in FIG. 10) that can reduce the blur component using PSF from the charge transport layer 5 component profile (film component profile shown in FIG. 10). Even for layer 5 components, it is possible to analyze the estimated component distribution of the film in the true depth direction, and it is possible to determine the migration of the charge transport layer 5 component from the interface reflection information (Rayleigh light profile). Therefore, the efficiency of developing an electrophotographic photosensitive member can be increased.

(Comparative Example 1)
As Comparative Example 1, interface reflection light “Rayleigh light leakage light profile (interface reflection intensity distribution)” and Raman obtained under the conditions of using “oil immersion lens + emulsion oil” in the apparatus configuration of FIGS. FIG. 8 shows the result when the deconvolution processing means for removing the device function is not applied to the “film component profile at each depth position” obtained by scattered light acquisition.

  As shown in FIG. 8, when the deconvolution process is not performed, the device function (blur) is superimposed on the surface layer / charge transport layer interface position where the film component rises steeply, and the skirt of the film component is spread. It is difficult to correctly evaluate the migration of the film component to the surface layer side at the surface layer / charge transport layer interface of the transport layer film component.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and other embodiments, additions, modifications, deletions, etc. Can be changed within the range that can be conceived, and any embodiment is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited.

1 Membrane sample (sample)
2 Cylindrical base (aluminum drum)
3 Interlayer 4 Charge generation layer 5 Charge transport layer 6 Surface layer 30 Laser light source 31 Condensing lens 32 First pinhole 33 Separation optical element (dichroic mirror)
34 Oil immersion lens (objective lens)
35 Second pinhole 36 Photodetection means (detection unit)
37 Filter optical element 38 Calculation means

Japanese Patent No. 4410154 JP 2010-117226 A

Ikehara, Nishi, “Utilization of confocal laser scanning microscope”, Functional Materials, Vol.22, No.10, p20-25 (2002)

Claims (8)

A laser light source for irradiating laser light;
A microscopic optical system having a separation optical element that receives Rayleigh light and scattered light from the sample irradiated with the laser light, and an objective lens that is an oil immersion lens;
A filter optical element that transmits light of a specific wavelength in the light that has passed through the separation optical element;
A spectroscopic means for splitting light transmitted through the filter optical element;
Photodetection means for detecting the intensity of the light split by the spectroscopic means,
The filter optical element guides a part of Rayleigh light from the sample to the light detection means so as to be measurable, and blocks the Rayleigh light from the sample and guides scattered light to the light detection means. It is provided to be selectable,
A Raman spectroscopic measurement apparatus comprising arithmetic means capable of deconvolution processing for removing an apparatus function component from a depth direction component profile of scattered light received by the light detection means.   The Raman spectroscopic measurement apparatus according to claim 1, wherein the microscopic optical system is a confocal microscopic optical system having a pinhole having a conjugate relationship with a focal plane.   3. The Raman spectroscopic measurement apparatus according to claim 1, wherein the filter optical element has a first laser light blocking optical element that blocks laser light equivalent to Rayleigh light so that it can be inserted and removed.   The filter optical element includes a first laser light blocking optical element that blocks laser light equivalent to Rayleigh light, and a second laser light blocking optical element that increases the transmittance with respect to the wavelength of laser light equivalent to Rayleigh light. The Raman spectroscopic measurement device according to claim 1, wherein the Raman spectroscopic measurement device is replaceable.   The Raman spectroscopic measurement apparatus according to claim 3, wherein the first laser light blocking optical element is a notch filter and / or an edge filter.   The Raman spectroscopic measurement apparatus according to claim 1, wherein the separation optical element is a dichroic mirror.   The Raman spectroscopic measurement apparatus according to claim 1, wherein the oil immersion lens included in the microscopic optical system is a combination of an oil immersion lens having an NA of 1.2 or more and emulsion oil. . A laser light source for irradiating laser light;
A microscopic optical system having a separation optical element that receives Rayleigh light and scattered light from the sample irradiated with the laser light, and an objective lens that is an oil immersion lens;
A filter optical element that transmits light of a specific wavelength in the light that has passed through the separation optical element;
A spectroscopic means for splitting light transmitted through the filter optical element;
A light detecting means for detecting the intensity of light split by the spectroscopic means;
A Raman spectroscopic measurement method of a Raman spectroscopic measurement apparatus having a computing means capable of deconvolution processing that removes a device function component from scattered light received by the light detection means,
Adjusting the filter optical element to guide a part of the Rayleigh light from the sample to the light detection means, detecting the reflected light intensity of the Rayleigh light at the film interface in the depth direction of the sample, and the depth position by Raman spectroscopy Associating with each spectral data profile;
Deconvolution of the depth direction component profile of the film that can be extracted from the obtained spectral data file for each depth position by Raman spectroscopy,
And a step of evaluating migration of the film component at the film interface as a result of the profile analysis of the depth direction component profile of the Rayleigh light and the film.

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