JPH07294455A - Surface flaw detecting method and device therefor - Google Patents

Abstract

PURPOSE:To increase the number of detectable flaw kinds by finding ellipsoparameters of surface reflected light by radiating polarized light to a surface to be inspected, comparing an amplitude ratio of reflected light from a previously found surface flaw with a phase difference characteristic, and grading it. CONSTITUTION:A change in a polarization parameter when an oxide film of about 5 to 100nm is stuck to a surface of a cold drawing steel plate, is expressed by a (DELTA-psi) chart by respectively setting an amplitude ratio (f) of P and S polarization and a phase difference (DELTA) on the axis of abscissa and the axis of ordinate. A plot marker shows a film thickness of the oxide film. Though (psi) changes when an oxide film thickness is about 20 to 50nm, (DELTA) mainly changes when it is about 0 to 20nm and about 50 to 100nm, and (9) hardly changes, and only (psi) is observed in this section, and nonuniformity of a thickness cannot be observed. Thereby, when two ellipsoparameters of (psi) and (DELTA) are simultaneously found, the oxide film thickness can be evaluated over a wide range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical surface flaw detecting method and apparatus.

[0002]

2. Description of the Related Art As an apparatus for optically detecting a surface flaw of a steel sheet such as a flaw on the surface of a thin steel sheet, an optical flaw detector using a laser beam as a light source and utilizing a change of a light scattering or a diffraction pattern is often used. It is used. This method detects flaws by changing the pattern of laser light scattering or diffraction due to flaws, and is an effective means in the case of flaws in which clear unevenness is formed on the surface of a steel sheet.

However, the flaws have no surface irregularities and are difficult to detect by the above-mentioned observation methods such as unevenness of physical properties, unevenness of microscopic roughness, local presence of thin oxide film, and unevenness of coating film thickness. Things exist. For example, 1 in the normal part
It is assumed that the steel plate surface having an oxide film of about 00Å locally has an abnormal portion with a thick oxide film of about 400Å. Hereinafter, such an abnormal portion will be referred to as a pattern defect. There is a demand to detect and remove such areas as defects such as defective coating in the lower process, but the difference in the oxide film thickness from the normal part is buried in the roughness of the steel plate surface, and the scattering of light and It cannot be detected at all by the method using diffraction.

A surface inspection method using polarized light is available to detect a flaw that is not sensitive to scattering and diffraction. For example, a method for finding foreign matter on a semiconductor wafer is Japanese Patent Publication No.
No. 23620. This method is a method for detecting a defect by obtaining Ψ among the polarization parameters, that is, the amplitude ratio (tan Ψ) of P-polarized light and S-polarized light. (P-polarized light is the component of the electric vector of the reflected light in the direction of the incident surface of the light, and S-polarized light is the component of the direction perpendicular to the incident surface.) However, the polarization component ratio is constant, and the normal / abnormal part changes. Due to surface defects, this method cannot be applied for the above-mentioned purpose.

Ellipsometry is a means for simultaneously measuring the P and S component ratios of polarized light and the phase difference. Japanese Patent Publication No. 4-7812
No. 2 and JP-A No. 1-211937 propose a method of testing the characteristic value of the material surface using ellipsometry. However, it was considered that these methods were too sensitive to be applied to the surface flaws of the material as described above, and could not be used to detect flaws in the steel sheet. As described above, it has heretofore been impossible to detect the pattern-like flaws of the steel sheet by optical means, and there is no such apparatus.

[0006]

In view of such a situation, the present invention uses the polarization characteristics of the reflected light from the surface to be inspected to increase the number of flaw types that can be detected and discriminated. It is intended to detect a pattern-like surface flaw that could not be detected.

[0007]

The ellipsoparameters (Ψ, Δ) are defined by the equation (1) via the ratio ρ of the reflectance Rs of the S component of polarized light to the P component reflectance Rp.

Ρ = Rs / Rp = tan Ψ · exp (jΔ) (1) where tan Ψ is the amplitude ratio of the P and S components of the reflected light, ex
p (jΔ) indicates the phase difference between the P and S components. When the incident light is linearly polarized light of 0 degree (only the P component), the angle formed by the principal axis of the ellipse formed by the P and S components of the reflected light with the incident surface is Ψ, and P and S
The phase difference of the components corresponds to Δ. In this case, it is possible to divide the reflected light at arbitrary polarization angles of two orthogonal axes, measure the respective polarization intensities, and calculate Ψ and Δ from the principal axis direction of the ellipse and the eccentricity. Further, the polarization state of the incident light can be set arbitrarily, and in that case, the polarization state of the incident light is corrected to obtain Ψ and Δ.

The intensity I of the reflected light is obtained by the equation (2) from the intensity Io of the incident light and the reflectance R of the surface. I = Io · R (2) When using such an optical measurement value, the above-mentioned problem is
The surface to be inspected is irradiated with polarized light to obtain the ellipsoparameters (Ψ, Δ) of the surface reflected light, and the amplitude ratio Ψ of the reflected light from the surface flaw and the phase difference Δ characteristic are calculated in advance, This is solved by providing a surface flaw detection method characterized by grading.

Further, the surface to be inspected is irradiated with polarized light to obtain the ellipsoparameters (Ψ, Δ) of the surface reflected light, and the same or different light is applied to the same portion of the surface to be inspected to reflect the surface. (I) is obtained, and the surface flaw detection method is characterized by determining the grade and type of the surface flaw based on the two ellipso parameters and the state of the reflection intensity.

The apparatus according to the present invention comprises means for storing in advance the ellipso parameter (Ψ, Δ) characteristics of surface flaws,
It is provided with means for irradiating the surface to be inspected with polarized light to measure the ellipsoparameters (Ψ, Δ) of the surface reflected light, and means for outputting the comparison result of the measured surface reflected light and the memory characteristic. And a surface flaw detection device.

Further, means for irradiating the surface to be inspected with polarized light to obtain an ellipsoparameter (Ψ, Δ) of the surface-reflected light,
Means for measuring the reflection intensity (I) by irradiating the same place on the surface to be inspected with the same or different light and the three-dimensional coordinate position of Ψ, Δ, I to which the light reflected from the surface to be inspected belongs are determined in advance. A surface flaw detection device comprising means for outputting as a range division.

When the surface to be measured is large, a plurality of two-dimensional image pickup devices are used as light receiving means for the reflected light, and Ψ, Δ or I is calculated using the photometric values of the pixels corresponding to the same reflection point. And a surface flaw detecting device. Further, the polarized light source is a monochromatic light source, the light source is used to irradiate a predetermined range on the surface to be inspected, and the range is shared by a plurality of ellipsometers for the reflected light from the surface to be inspected. The flaw detection device is designed to receive light.

[0014]

[Function] Since the polarization characteristics are sensitive to the surface properties of materials,
It is possible to measure surface properties that cannot be detected using scattered light or diffraction. The surface of the pattern-like flaw has a change in characteristics related to light reflection, and the ellipso parameter changes sensitively. However, conventionally, it has not been known what kind of means can be used to associate a change in ellipso parameter with a defect. The inventors, as a result of investigating the relationship between the ellipso parameter and the surface defect, in the case of a pattern-like defect, Ψ and Δ change with functional characteristics depending on the range of the film thickness of the oxide film to be detected as a defect, It was found that the defect part and the normal part can be distinguished by using this characteristic.

With regard to a pattern-like flaw in which a foreign matter is placed on the film, surface irregularities accompany it, and therefore the optical reflectance changes at the same time as the ellipso parameter. In this case, a flaw and a normal portion can be discriminated by a combination of a change in ellipso parameter and a change in reflectance intensity. Further, since this combination is reproduced depending on the type of the flaw, the degree and type of the flaw can be determined by combining the intensity change of the reflected light and the ellipso change.

The ellipsometer is generally an apparatus for obtaining each point on the surface by using a plurality of light receiving elements.
However, the inventors propose a device using a two-dimensional image sensor. When measuring the ellipsometer parameters and the reflection intensity of a wide range of surfaces to be inspected, the surface of the object is divided into a plurality of optical systems to form an image on a two-dimensional image sensor. In the measurement of the ellipsometer and the light intensity, the light intensity measured by a plurality of image pickup devices is calculated using the intensity of the device corresponding to the same position on the surface to be measured. If the reflected light intensity at the same reflection point is obtained by correcting the optical system, the optical system becomes simpler than scanning with a single photometric means.

Further, the light source includes a laser light source having a relatively large output. When measuring a wide range of ellipsometer parameters using one laser light source and multiple ellipsometers, if the light from a common light source is dispersed and irradiated using an optical fiber, the irradiation intensity in each part of the wide material will be uniform. Therefore, it becomes easy to correct the reflected light intensity.

[0018]

FIG. 1 shows a first embodiment of the present invention. FIG. 1 shows how the polarization parameters change when an oxide film of 5 nm to 100 nm adheres to the cold rolled steel sheet. FIG. 1 is a “Δ-Ψ chart” used in general polarization analysis, in which the horizontal axis represents the angle Ψ representing the amplitude ratio of P and S polarized light, the vertical axis represents the phase difference Δ of P and S polarized light, and the plot marker is The film thickness of the oxide film measured by another means is shown. The measurement conditions are such that an oxide film having a refractive index of 3.0 is present on a steel plate having a complex refractive index of 2.0 + i4.0 with a He-Ne laser having a wavelength of 633 nm and a measurement incident angle of 70 degrees.

In FIG. 1, the oxide film thickness is 20 to 50 nm.
A change in Ψ is observed up to a certain degree, but a change in Δ is mainly observed in 0 to 20 nm and 50 to 100 nm, and Ψ hardly changes. Therefore, the control range of the oxide film thickness is 0 to 2
Even if the thickness unevenness in 0 nm or 50 to 100 nm is to be detected as a flaw, it is impossible to detect it by observing only Ψ. Therefore, according to the present invention, Ψ and Δ are simultaneously obtained and applied to this relational expression to evaluate a wide range of oxide film thickness. For example, when Ψ is around 35 degrees and Δ is in the range of 100 degrees to 250 degrees, the film thickness is 50 nm to 100 nm and 0 nm to 20 n.
Convert with two line segments corresponding to m. When Ψ is 40 degrees or more and Δ is outside the range of 100 degrees to 250 degrees, the film thickness is 20 nm to 35 nm and 35 nm to 50 nm.
Converted by the line segment corresponding to nm. The normal range of the film thickness is determined by the steel type, the thickness, etc., and the part where the film thickness is out of the control range is detected as a flaw.

A second embodiment of the present invention is shown in FIGS. FIG. 2 shows an example in which a type A flaw is detected in the patterned flaws. The flaw extends linearly, and the ellipso parameter and the reflected light intensity in the range of 20 mm width are displayed in such a manner that the line is located at the center in the horizontal direction of the figure in correspondence with the position in the width direction. As for the phase difference (Δ) and the intensity (I) of the flawed portion, it is more difficult to determine the presence of the flaw than in the normal portion (other than the central portion in the lateral direction). However, the amplitude ratio (Ψ) can clearly distinguish between a portion with a flaw (central portion) and a portion without a flaw (other than the central portion). This flaw is a thin oxide film on the surface and cannot be detected by a conventional optical inspection machine.

FIG. 3 shows an example in which a B-type flaw is detected in the patterned flaws. Although the presence of a flaw cannot be identified by Ψ, it is felt by the phase difference (Δ) and the intensity (I). B type defects often appear when the microscopic surface roughness of the steel sheet changes. The cause is when the surface of the rolling roll is partially roughened.

FIG. 4 shows an example in which a C type flaw is detected in the patterned flaws. In the case of this flaw, I feel all the parameters of Δ, Ψ, and I. Type C is a flaw in which the apparent roughness of the surface of the steel sheet has changed significantly due to the deposit on the patterned flaw. It is an adhering matter that can be visually recognized, and can be detected by a conventional inspection machine.

As shown in FIGS. 2 to 4, depending on the type of the flaw, there are those with a change in the intensity of the reflected light and those with no change. Also, the value of the ellipso parameter changes depending on the type of flaw.

Next, an example of means for discriminating the type of flaw will be described. Since the intensity, Ψ, and Δ values may partially change, it is difficult to obtain the absolute values. Therefore, the moving average of each parameter is measured and the change from the average value is detected. Take the moving average constant according to the size of the flaw. When a change above a certain level is detected, the absolute value of the angle is used as the evaluation value for the ellipso parameter, and the amount of change from the average value is used as the evaluation value for the reflection intensity. The absolute values of Δ and Ψ and the amount of change in reflection intensity form a three-dimensional space. This three-dimensional space is divided into sections based on empirical rules, and each section is applied to the type and grade of defects. If a plurality of sections have common flaws, it is also possible to group these and display the sections by grade.

The ellipso parameter measuring apparatus has various changes depending on the optical system. The inventors of the present invention first described the reflected light 4
An optical system has been proposed in which not only the ellipsoparameters (Ψ, Δ) but also the absolute value of the phase angle Δ can be known by obtaining the two polarization components, and the change of the incident light intensity can be corrected (JP-A-5-113371). See the bulletin). FIG. 5 shows a third embodiment of the present invention in which a surface flaw detection device is constructed by using any of the optical systems proposed by this.

The surface flaw detection apparatus shown in FIG. 5 uses an ellipsometer main body 1, an ellipsometer parameter computing unit 3 for computing ellipsometer parameters from its output, and an ellipsometer parameter when a specimen 2 having flaws is used. -Ellipso parameter storage device 4 for storing the data, and an ellipso parameter for comparing the ellipso parameter with the characteristic value of the defect stored in the storage device 4 when the sample 2 having unknown characteristics is used. It comprises a comparison device 5 and a defect signal output device 6 for outputting the presence / absence of a defect, a grade, etc. according to the comparison result.

The ellipsometer body 1 is composed of, for example, the optical system shown in FIG. In FIG. 6, 10 is a laser light source, 11 is a polarizer, and 12 is incident light. The incident light 12 is linearly polarized by the polarizer 11 and is reflected on the surface of the sample 2. The reflected light 13 is divided into four different polarized lights 18a, 18b, 18c and 18d by the beam splitters 14, 15 and 16 and the quarter wavelength plate 17 and is divided by the respective light receivers 19a, 19b, 19c and 19d. Intensities I ₁ , I ₂ , I ₃ , I ₄ are detected.

The ellipso-parameter arithmetic unit 3 calculates the ellipso-parameters from these light intensities according to equations (3) and (4).

Tan Δ = [σ_R(I₁-I₂)] / [Σ_T(I₃-I_Four)] (3) tan Ψ = [(σ_R ²−σ_T ²) / 2] ・ [{σ_R(I₁-I₂)}²] + {Σ_T(I₃-I_Four)}²]^1/2÷ (σ_R ²(I₁＋ I₂) −σ_T ²(I₃＋ I _Four )] (4) where σ_R, Σ_TEach is a non-polarizing beam splitter
14 P-polarized and S-polarized amplitude reflectance ratio, and amplitude transmission
The ratio is a value specific to the optical component.

The ellipso parameter storage device 4 stores the characteristics of the ellipso parameter when a sample 2 having a flaw is used in advance. For example, the characteristics of the oxide film as shown in FIG. 1 are stored.

When the ellipso parameter comparing device 5 obtains the ellipso parameter of the sample 2 having an unknown characteristic, it compares it with the characteristic previously measured and stored. For this, interval division processing in the Ψ and Δ dimensions is applied.
As a result, a film thickness signal is output. Defect signal output device 6
Sets a criterion for acceptance / rejection based on the film thickness, and normalizes when the film thickness is within a predetermined range, and outputs an alarm as abnormal when the film thickness is out of the predetermined range.

A fourth embodiment of the present invention is shown in FIG. Figure 7
Shows the part of the optical system in the apparatus in which the present invention is applied to the traveling line of steel plates. The optical system of this embodiment includes a system for obtaining an ellipso parameter and a system for obtaining a reflection intensity. In this embodiment, since the intensity of the incident light is made uniform in each part of the sample and the temporal change is eliminated, three polarization components of the reflected light are obtained in both systems, and the intensity (I) of the reflected light and the ellipso are calculated by these calculations. The parameters (Ψ, Δ) can be calculated.

First, in the ellipso parameter system, the light emitted from the high-intensity light source 20 is polarized by the polarizing plate 23 and then irradiated on the surface of the sample 2. The light reflected from the surface is separated by a warrant prism 26 into two polarization components orthogonal to each other at 45 ° and −45 °, and a camera B using a two-dimensional CCD element measures the polarization intensity for each pixel. Camera B is a CC
The method is such that separate images are formed on different parts of the D camera. It is also possible to divide the image into two separate cameras and shoot separately by changing the optical system. The light intensity of the camera B is output to an ellipsometer calculation device (not shown in the figure) and these two light intensities are calculated to obtain the ellipso parameter at each point on the sample surface.

Next, a system for measuring the reflection intensity will be described. The light emitted from the high-intensity light source 20 is applied to the surface of the sample 2 after having a uniform intensity distribution by the diffusion plate 21. The light reflected from the surface is reflected by the surface of the non-polarizing prism 25, passes through the polarizer 24 whose polarization angle is set to 0 degree, and then enters the camera A27. In the camera A, the light intensity at each point on the measurement surface is simultaneously obtained using a two-dimensional CCD element. In the case of the optical system of FIG. 7, the reflection intensity (I) is obtained by I = I ₂ + I ₃ −2I ₁ . Here, I ₁ is the light intensity obtained from the cameras A, I ₂ , and I ₃ from the 45-degree and −45-degree polarized images of the camera B, respectively.

The optical system shown in FIG. 7 is characterized in that a wide range is uniformly illuminated with polarized light, and ellipso parameters and reflection intensities of a large number of points on the sample surface are simultaneously calculated from an image with a polarization angle of 0, 45, or −45 degrees. That's what I was able to do. The ellipso parameter output is converted into a film thickness or a defect type by comparing with the memory pattern.

FIG. 8 is a signal processing system diagram of an apparatus for detecting flaws by simultaneously using the reflected light intensity and the ellipso parameter.
This is a device corresponding to the part that processes the output of the optical system in FIG.

Output signals from the cameras A and B are temporarily stored in the frame memories A31 and B31. Since the image of two polarization angles is stored in the frame memory B, the same point on the sample surface, together with the frame memory A storing the light intensity, gives a total of three light intensity information. At this time, since positional shifts occur in Δ, Ψ, and I on the frame memory depending on the viewing angle, the position scale correction device 32 obtains the image of the three polarization components captured in the frame memory from the Fresnel coefficient of the optical system. Perform the processing to match the position and scale. Next, the Δ, Ψ, I calculation device 33 performs the Δ, Ψ, I calculation for each matched pixel. Equivalent complex refractive index calculation device 3
5 calculates the equivalent complex refractive index of each point of the sample from Δ, Ψ and I calculated from the reflected light based on the polarization state of the incident light.
After performing appropriate mapping processing on these calculation results,
The surface state is displayed on the display device 36. For simplicity, the images of Δ, Ψ, and I may be directly compared with the past data.

FIG. 9 shows an example of mapping processing for the flaws shown in FIGS. FIG. 9a is a discrimination diagram applied when the reflection intensity I rises from the normal value. When Δ and Ψ are in the shaded area in the figure, they correspond to grades 1, 2, and 3 of D type flaw. FIG. 9b applies when the reflected light intensity is at a normal value. The types and grades of A and B are assigned as shown by the shaded areas according to the values of Δ and Ψ. Similarly, c and d in FIG. 9 are applied when the reflected light intensity drops from the normal value. In this case, regardless of the values of Δ and Ψ, the defect type and the grade are assigned only by the intensity classification.

FIG. 10 shows a fifth embodiment of the present invention in which multi-channel ellipsometers are arranged in parallel. This device has 2
Wide steel plate 40 with a width of 000 mm has a maximum line speed of 600 m
The purpose is to detect flaws while moving per minute. The light source is a laser 41 having a wavelength of 800 nm, and this light is guided near the surface to be measured using an optical fiber 42. The incident light is linearly polarized by 45 degrees by the polarizing plate 43. The incident angle on the steel plate surface was 65 degrees. Instead of an optical fiber, a parabolic mirror may be used to convert the laser light into slit-shaped parallel rays and irradiate the steel sheet. The light detection cameras 44, 45, 46 are 10
Width resolution of 0.2 using 24-pixel one-dimensional CCD
The width of the steel plate was seen to be 250 mm with one channel of 5 mm.

An image processing device is attached to each of heads 1 to 8 to calculate the polarization intensity at a speed commensurate with the line speed. In order to improve the processing speed, the Δ, Ψ, I arithmetic unit 33 has 8
The set is processed in parallel. If the line speed is slow,
Alternatively, when the resolution is low, the number of parallel processings can be increased to reduce the number of devices. These signals are subjected to ellipso parameter calculation in the image processing device 34, and then the mapping display device 36 determines a flaw.

In the mapping process of this embodiment, when a flaw appears in the image, the flaw type is discriminated by the combination of which parameter among Δ, Ψ and I is changing. The degree of the flaw is determined, for example, with respect to Δ in FIG. 4, by the degree of change from the value Δ of about 113 ° in the normal portion to the value Δ of 98 ° in the flaw portion. In FIG. 4, when the change value of Δ is within 2 ° to 3 °, it is a flaw that is not harmful, but since it is unacceptable as the shipping quality, a warning is output as an abnormal portion. Oil is applied to the steel sheet to be inspected, but since it has a basic function as an ellipsometer, it is possible to measure the unevenness of the oil film thickness.

In all of the above embodiments, the light source for obtaining the light intensity and the light source for obtaining the ellipso parameter are the same. These do not necessarily have to be the same, and a normal light source for obtaining reflected light and a polarized light source for obtaining ellipso parameters may be installed independently.

[0043]

By comparing the ellipso parameter with the stored value, it becomes possible to detect a pattern-like flaw on the surface of a steel sheet which could not be detected by the conventional method. Since the ellipso parameter and the reflected light intensity are combined, it is possible to determine the type of flaw. Since the two-dimensional image pickup device is used, the optical system becomes compact. Further, when applied to a wide material, the light from the light source is guided by an optical fiber, so that the irradiation light becomes uniform and accurate measurement can be performed with simple correction.

[Brief description of drawings]

FIG. 1 is a view showing an ellipsometer when an oxide film is attached on a steel plate.

FIG. 2 is a diagram showing a reflection characteristic of a type A flaw.

FIG. 3 is a diagram showing a reflection characteristic of a type B flaw.

FIG. 4 is a diagram showing a reflection characteristic of a type C flaw.

FIG. 5 is a diagram showing an embodiment of a flaw detection device according to the present invention.

FIG. 6 is a diagram showing an example of an ellipso-parameter optical system.

FIG. 7 is a diagram showing an embodiment of an optical system according to the present invention.

FIG. 8 is a diagram showing an embodiment of a signal processing system according to the present invention.

FIG. 9 is a diagram showing an example of mapping according to the present invention.

FIG. 10 is a diagram showing an embodiment of a flaw detection device according to the present invention.

[Explanation of Signs] 1. Ellipsometer body 2. Sample 3. Ellipso parameter calculation device 4. Ellipso parameter storage device 5. Ellipso parameter comparison device 6. Defect signal output device 10. Laser light source 11. Polarizer 12. Incident light 13. Reflected light 14. Non-polarizing beam splitter 15.16. Polarization beam splitter 17.1 / 4 wave plate 18. Polarized beam 19. Light receiver 20. High brightness light source 21. Diffusion plate 22. Monochromatic filter 23. Polarizing plate 24. Polarizer 25. Non-polarizing prism 26. Warrant prism 27. Camera A 28. Camera B 30.31. Frame memory 32. Position scale correction device 33. Δ, Ψ, I arithmetic unit 34. σ correction device 35. Equivalent complex reflectance calculation device 36. Mapping display

Claims (6)

[Claims] 1. An ellipsoparameter (Ψ, Δ) of surface-reflected light is obtained by irradiating the surface to be inspected with polarized light, and the amplitude ratio Ψ and phase difference Δ characteristic of the reflected light from the surface flaw, which has been obtained in advance, are obtained. A method for detecting surface flaws, characterized by grading as compared with. 2. The surface to be inspected is irradiated with polarized light to obtain the ellipsoparameters (Ψ, Δ) of the surface-reflected light, and the same or different light is applied to the same location on the surface to be inspected to reflect the surface. (I) is found, and the surface flaw detection method is characterized by determining the grade and type of surface flaw based on the two ellipso parameters and the state of the reflection intensity. 3. Ellipso parameters (Ψ, Δ) for surface flaws
Means for storing characteristics in advance, means for irradiating the surface to be inspected with polarized light to measure the ellipsoparameters (Ψ, Δ) of the surface reflected light, and outputting the comparison result of the measured reflected light and the memory characteristics. A surface flaw detection device comprising means. 4. A means for irradiating a surface to be inspected with polarized light to obtain an ellipsoparameter (Ψ, Δ) of the surface reflected light, and irradiating the same portion of the surface to be inspected with the same or different light for reflection. A surface flaw characterized by comprising means for measuring intensity (I) and means for outputting the three-dimensional coordinate positions of Ψ, Δ, I to which the reflected light from the surface to be inspected belongs as a predetermined range segment. Detection device. 5. A plurality of two-dimensional image pickup devices are used as light receiving means for the reflected light, and Ψ, Δ to I are calculated using photometric values of pixels corresponding to the same reflection point.
The surface flaw detection device according to any one of claims 1 to 4. 6. The polarized light source is a monochromatic light source, and the light source is used to irradiate a predetermined area on the surface to be inspected, and the light reflected from the surface to be inspected is irradiated by a plurality of ellipsometers on the area. The surface flaw detection device according to any one of claims 3 to 4, wherein the surface flaw detection device is configured to share the light.