JPH116795A - Method and device for analyzing contamination degree of metal surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to measure the presence of contaminated material of the junction part of an electronic device by comparing the ratio of the P-polarized component and the S-polarized component in the reflected light when the metal surface that is the sample with the predetermined threshold value is irradiated with the light of the specified wavelength. SOLUTION: The output light of a light source 11, which is, e.g. He-Ne laser (wavelength of 633 nm) is expanded by a beam expander 12, condensed by a condenser lens 13 after homogeneous action and irradiated on a sample 21 mounted on an X-Y stage 17. The reflected light at the sample 21 passes through a polarization plate 14 for selecting the P-polarized component or the S-polarized component in the reflected light and a pinhole 15 and then applied into a photodetector 16. As the polarization plate, a Glan-Thompson prism is used, and a rotary mechanism is attached. Then, it is irradiated with the P-polarized wave and the S-polarized wave respectively. The intensity of the reflected light of the respective polarized wave is measured. The ratio of the P-polarized component and the S-polarized component is compared with the predetermined threshold value. Thus, the contamination degree of the rough metal surface is evaluated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an integrated circuit (IC).
And a method for analyzing the surface roughness and the degree of surface contamination of a metal material, which are performed to verify whether the bonding strength performed on the surface is perfect in the manufacturing process of a HIC (Hybrid Integrated Circuit) or the like. About.

[0002]

2. Description of the Related Art As electronic devices such as semiconductor devices are further miniaturized and highly integrated, metal electrodes formed on these electronic devices for, for example, wire bonding are becoming finer. ing. For example, gold (A
The connection pad used for the wire bonding of u) has a size of 80 to 100 μm, is made of gold or aluminum (Al), and is formed by a method such as electrolytic plating or sputtering. Then, a gold wire is connected to this pad by an ultrasonic thermal connection method, thereby completing wire bonding. At that time, the surface of the connection pad is often intentionally roughened in order to ensure the connection of the gold wire.

As described above, the surface of a connection pad having a rough surface is often contaminated with a mask material, a surface treatment material, a resist material, and the like at the time of fine processing. In some cases, the wire bonding is not performed properly, resulting in a connection failure. For this reason, it is strongly desired to measure the degree of contamination of a minute metal rough surface.

[0004] It is difficult to measure the degree of contamination of a minute and rough surface such as the connection pad described above, especially when measuring in the atmosphere. Although it was possible to measure the decrease in light reflection intensity due to contamination using an optical microscope, there was no way to analyze the light reflected from the rough surface, and the measured values could not be interpreted.

Another possibility is to use a microscopic FT
It is conceivable to identify and evaluate the organic compound on the surface by IR (Fourier transform infrared absorption) spectroscopy. However, since the connection pads and the like have a small area and a rough surface, the reflection intensity of infrared light is low. Sufficient infrared absorption spectrum cannot be obtained.

In the microscopic FTIR spectroscopic analysis method,
It is difficult to analyze a surface layer as thin as about 0.1 μm, and there is a problem with the thickness of the sample. In fact, it has been known that the bonding strength of a finely bonded portion of an electronic component cannot be obtained due to a thin organic contaminant layer of 0.1 μm or less.

As a method of analyzing a thin surface layer, use of an Auger electron spectrometer can be considered. Auger electron spectroscopy allows thin surface layers to be analyzed, but it takes another 5 minutes per particle analysis, such as by placing a sample in a vacuum device. Therefore, it is necessary to irradiate the sample with an electron beam of 5 keV or more, and there is a concern that the sample may be damaged.

Further, the organic fine particles on the surface are decomposed by irradiation with an electron beam to become carbon impurities and remain on the sample. Since the production of IC chips is performed in an ultra-high clean room, there is a concern that the particle analyzer itself may cause contamination, and it is not usual to put electronic devices directly into the analysis room of an Auger electron spectrometer. .

[0009]

Among the methods and devices for measuring the degree of contamination of a minute metal rough surface, when using an optical microscope, there is no method for analyzing the reflected light from the rough surface. There is a problem that the measured values cannot be interpreted.

When microscopic FTIR spectroscopy is used, the reflection intensity of infrared light is insufficient, a good infrared absorption spectrum cannot be obtained, and a thin surface layer cannot be analyzed. There is a problem.

When using an Auger electron spectrometer,
There is a problem that it is difficult to use it near a production line because the operation is complicated, time-consuming, and expensive.

In addition, since the size of each device is large, it is difficult to ground the device near the production line even if the above-mentioned problems are eliminated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to quickly measure the presence of contaminants at a junction of an electronic device having a diameter of 100 μm or less. It is an object of the present invention to realize a surface layer analyzer and a method for analyzing a metal rough surface capable of extracting a HIC being manufactured from a manufacturing line, analyzing a surface in about one minute, and returning a measuring device to the manufacturing line. .

[0014]

According to the method for analyzing the degree of contamination of a metal surface according to the present invention, the ratio between the p-polarized component and the s-polarized component in the reflected light when a specific wavelength light is applied to the metal surface as a sample. Is compared with a predetermined threshold value to analyze the degree of contamination of the metal surface.

In this case, the threshold value may be changed according to the type of the metal whose contamination degree is to be analyzed.

Further, in the case of sp metal such as Au, Cu, and Al, the value obtained by removing the s-polarized light component by the p-polarized light component is 1.3.
The following analysis may be made as contamination, and the transition metal surface may be analyzed as contaminated when the value obtained by removing the s-polarized component by the p-polarized component is 3 or less.

According to another aspect of the present invention, there is provided a method for analyzing the degree of contamination of a metal surface, wherein the ratio of the p-polarized component to the s-polarized component in the reflected light when a specific wavelength light is applied to the metal surface as a sample is:
The method is characterized in that the degree of contamination of the metal surface is analyzed based on whether the metal surface is separated from a predetermined value by a predetermined distance.

The predetermined value and the predetermined distance may be made different depending on the type of metal whose contamination degree is to be analyzed.

Further, in the case of a sp metal such as Au, Cu, or Al, the predetermined value is set to 1.3 and the predetermined distance is set to 0.3. In the case of a transition metal surface, the predetermined value is set to 3.0 and the predetermined distance is set to 0.3. 0.5
A method for analyzing the degree of contamination of a metal surface, characterized in that:

In a method for analyzing the degree of contamination of a metal surface according to another embodiment of the present invention, a specific wavelength light is applied to a plurality of portions of a metal surface as a sample, and a ratio of a p-polarized component to an s-polarized component in reflected light is measured. Is plotted as the abscissa, and the ordinate is plotted as the existence probability indicated by the number of locations where the respective polarization reflectance ratios R = s / p are measured, and the half-width of the graph is used to analyze the degree of contamination of the metal surface. It is characterized by the following.

The p-polarized light component in the reflected light and the s-
The ratio of polarization components departs from the theoretical value when the surface is clean as contamination progresses. This is because the interaction of the s-polarized wave and the p-polarized wave with the metal surface becomes incomplete due to the contaminant molecules, and the irregular reflection by the rough surface changes depending on the degree of contamination. The present invention focuses on this phenomenon, and p
The contamination degree can be determined by a small procedure of comparing the ratio between the -polarized component and the s-polarized component with a threshold value.

What is important here is that the theoretical value when the surface is clean differs depending on the type of metal. However, in the present invention, contamination is caused between the case of sp metal and the case of transition metal as described above. Since the threshold value for determining the degree is polarized, accurate determination can be performed.

The apparatus for analyzing the degree of contamination of a metal surface according to the present invention is a polarization analyzer for detecting the ratio of the reflected light of the p-polarized component and the reflected light of the s-polarized component when a specific wavelength light is applied to the metal surface as a sample. Unit, an XY stage for moving the sample, and a stereoscopic microscope for observing the metal surface, wherein the polarization analyzer is configured to obtain a reflection intensity obtained by moving the sample by the XY stage. The thickness of the surface layer and the dielectric constant of the surface layer are represented by two-dimensional mapping by R _os and R _op .

In this case, the ellipsometer may cause the light of a specific wavelength to enter the sample at an incident angle of 60 ° ± 10 °.

Further, a polarizing plate for extracting reflected light of the p-polarized light component and the s-polarized light component may be provided on the reflected light side.

The apparatus for analyzing the degree of contamination of a metal surface configured as described above can determine the degree of contamination as described above and is suitable for miniaturization.

[0027]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. This embodiment employs a configuration in which a polarization analyzer and a stereoscopic microscope are combined.

First, the configuration of the optical system of the polarization analyzer of this embodiment will be described. The optical system according to the present embodiment includes a light source 11, a beam expander 12, a condenser lens 13, a polarizing plate 14, a pinhole 15, and a photodetector 16. He-Ne laser with output 5mW (wavelength 6
The output light of the light source 11 of 33 nm) is enlarged and uniformed by the beam expander 12 and then condensed by the condensing lens 13 to irradiate the sample 21 placed on the XY stage 17. The reflected light from the sample 21 passes through a polarizing plate 14 for selecting a p-polarized component or an s-polarized component in the reflected light, and a pinhole 15 for narrowing down the reflected light from a measurement point on the sample 21. Later, the light enters the photodetector 16.

Next, the control system of this embodiment will be described.

Generally, a Glan-Thompson prism is used as the above-mentioned polarizing plate 14. In this embodiment, a rotating mechanism (not shown) for rotating the polarizing plate 14 is additionally provided. By rotating the polarizing plate 14 by a mechanism, a p-polarized component or an s-polarized component can be selected. The control device 18 controls the rotation of the polarizing plate 14 and the drive control of the XY stage 17.

The control device 18 receives the detection output of the photodetector 16, a video signal indicating the content of the image output from the stereo microscope 20, and a signal indicating the content of the instruction from the input device 22.
The rotation of the polarizing plate 14 and the drive control of the XY stage 17 are performed according to the signal content of the input device 22, and the calculation based on the obtained measurement values is performed. The image is displayed on an output device 19 having an image display capability such as a CRT, a printer, or a plotter. The center of the observation point by the stereomicroscope 20 (magnification: 200) is the center of the ellipsometer, that is, the sample 21 on the XY stage 17, as is the focal position of the condenser lens 13.

In the present embodiment, the surface analysis is performed by the polarization reflection method of the laser beam, and the measurement is performed in the air using the weak (5 mW) laser beam having the wavelength of 633 nm as described above. Therefore, the sample is not destroyed and can be easily performed. What can be observed by the present embodiment are surface roughness (measurement of unevenness value), s-polarized light, p-polarized light reflectance, surface layer thickness and dielectric constant. 5
Measure in the analysis area of μm ² .

When the measurement at the predetermined position is completed, the control unit 18 sets the observation point to 5 μm by 2 mm by the XY stage 17.
Observe by moving it dimensionally. Thereby, the observation data at each measurement point is continuously taken in, the observation point dependence of the reflectance and the change in the surface state are observed, and various amounts of the surface distribution are displayed on the output device 19.

As described above, the light source 11, the beam expander 12, and the condenser lens 13, the polarizing plate 14, the pinhole 15, and the photodetector 16 are provided on the XY stage 17 on the incident side and the reflection side of the sample 21. And placed. These are provided on an arm (not shown) serving as a support member. In this embodiment, the arm has an incident angle of 6
The angle is preferably set to 0 ° ± 10 °, and in this embodiment, the angle is set to 60 °. With such an incident angle, the irradiation area on the sample 21 can be set to about 5 μm ² , and the size of the apparatus can be reduced. Further, a feature of the optical system of the present embodiment is that the polarizing plate 14 is provided on one side on the reflected light side of the sample 21. With such an arrangement, the sizes of the optical systems sandwiching the sample 21 can be made substantially equal, and the size of the apparatus can be reduced from this point as well. As described above, the apparatus according to the present embodiment can be configured to be extremely small, can be grounded in the vicinity of the production line, and can perform measurement quickly because the movement of the sample is small.

In this embodiment configured as described above, the following can be observed, and the control unit 18
Outputs these to the output device in the form of a two-dimensional mapping.

1. 1. Distribution of surface roughness σ (x, y) (nm) 2. p / s polarization reflection intensity ratio distribution 3. thickness of surface layer Calculation of Dielectric Constant of Surface Layer Each measurement principle in the present embodiment configured as described above will be described below.

1. Distribution of surface roughness σ (x, y) (nm)
The reflected light is determined by scattering due to surface roughness and absorption by the surface layer, and the observed reflectances of s-polarized light and p-polarized light, R _os and R _op , respectively, are R _os = R _ou × R _s R _op = R _ou × R _p . R _s and R _p are _{s on} the smooth surface
-Reflectance of polarized light and p-polarized light.

Here, R _ou is the reflectance due to the surface roughness σ, and assuming that the wavelength of the measuring light is λ, R _ou = exp [− (ασ / λ) ² ], α ≒ 1.5 Surface roughness σ can be determined from the measured values.

Σ (x, y) = Gc · [−lnR_ou(X, y)]^1/2 R_ou= 1 / Gp [R_os× R_op/0.30]^1/2 Here, Gc is the display value of the present embodiment and the display of other measuring devices.
It is just a coefficient to make it common with the value. This embodiment
Because the roughness is arbitrary units in the device of
Place 680 according to the more used surface roughness meter
Was. Further, Gp is specific to the optical system of the apparatus shown in FIG.
This is a parameter for eliminating the influence.
Of all the emitted light,
If the sum is 1 / 0.50, it is set to 0.50.
Further, R_ouR to define _op0.30 which divides
This is a parameter for eliminating the influence of the optical system.

[0041] 2. For p / s polarized reflection intensity ratio distribution _{R = Rs / Rp = R os} (x, y) / R op (x, y) 3. Calculation of Surface Layer Thickness and Dielectric Constant Regarding the method of analyzing the surface layer thickness and dielectric constant, the dielectric constant and thickness of the surface layer in this example are Feibelma
It has been analyzed and determined according to the formulation of the surface response function of n.

In this embodiment, the light source 1 is applied to the rough metal surface.
1 is incident obliquely (for example, the incident angle _θo is 60 °), the intensity of the reflected light reflected on the rough metal surface on the sample 21 is measured, and the intensity of the reflected light is used to determine the appropriate model. Is used to analyze the dielectric constant of the rough metal surface to evaluate the degree of contamination of the rough metal surface. At that time, a pair of linearly polarized light components, that is, s-polarized light and p-polarized light are respectively irradiated, and the reflected light intensity for each of these polarized waves is measured. The p-polarized wave is a polarized light having an electric field component parallel to the incident surface (rough surface of metal), and the s-polarized wave is a polarized wave whose electric field component is orthogonal to the p-polarized wave.

As is well known, the reflection intensity of light from a smooth solid surface is described by the Fresnel equation. Assuming that the permeability μ is substantially equal to the vacuum permeability μ _o , Snell's refraction equation

[0044]

(Equation 1) Is used, for s- and p-polarized waves,

[0045]

(Equation 2) Is given. r _s ^o and r _p ^o are the s-polarized wave and p
-Represents the classical (complex) amplitude reflectivity for polarized waves. The classical reflectivities r _s ^o and r _p ^o are determined by the angle of incidence θ _o , the permittivity of the gas phase ε _o , and the permittivity of the solid phase bulk ε _b and do not include terms relating to the properties of the solid surface . In order to capture surface effects such as a smooth change in dielectric constant on a solid surface, the reflectance expressed by equations (1) and (2) must be
It needs to be improved by theories such as (Fabelman) and Bagchi (Bagchi), and the non-classical reflectance improved in this way is obtained as follows.

[0046]

(Equation 3) here,

[0047]

[Outside 1] Is called Feibelman's surface response function, which is a parameter representing the surface properties, and is considered to represent the degree of contamination, surface roughness, and the like. ω is the angular frequency of the incident light. In particular, the real part of the surface response function is considered to represent the thickness of the surface layer. Therefore, by defining the dielectric constant ε _s of the surface layer using the equations (3) and (4), and calculating the reflectance based on the form of the equations (1) and (2), the surface The dielectric constant ε _{s of the} layer can be determined, and the degree of contamination of the rough surface metal can be evaluated. Incidentally, Equation (3), the reflectance r _s of (4), r _p is generally a complex number, it is measured s-
Polarized light and p- polarized wave of the reflected light intensity R _s, between the _{R p, R s = r s} r s *, R p = r p r p * the relationship is established.
Here, ^* indicates a complex conjugate, and R _s and R _p are converted into real numbers by this calculation.

The apparatus according to the present embodiment displays the various quantities by analyzing the reflection intensities R _os and R _op . The mode of analysis differs depending on the contents of the instruction input to the input device 22. For example, when an input indicating that the contamination degree is to be analyzed is performed, the analysis is performed only by measuring the p / s polarization reflection intensity ratio distribution. Therefore, it is possible to perform the operation promptly. The result of actually performing such a measurement will be described below.

The measurement was performed on the sample placed in the contaminated environment at every predetermined time, that is, in the situation where the degree of contamination gradually increased, ie, the polarization reflectance ratio R = s / p. FIG. 2A is a diagram showing a change in the polarization reflectance ratio s / p from an Au pad contaminated by the resist material, and FIG. 2B is a lead contaminated by organic and Fe ₂ O ₃ and NiO. Polarized reflectance ratio s / p of relay contact part (Rh material)
FIG. 2A and 2B, the polarization reflectance ratio R = s / p decreases as time passes and the degree of contamination increases. When the surface is contaminated, the s-polarized wave, p-
This is explained by the fact that the interaction with the polarized wave is incomplete and s / p is reduced.

What is important in the polarization reflectance ratio R = s / p is that
The value when clean is different depending on the type of the sample. In the case of an sp metal such as Au shown in FIG. 2A, the theoretical value of the polarization reflectance ratio R = s / p of a clean one is around 1.3.

Also, as in Rh shown in FIG.
In the case of a d metal (transition metal) having at least one or more electrons in an unfilled d subshell when in an ordinary oxidation state such as an atomic number of 22 to 28, 40 to 46, or 72 to 78, The theoretical value of the polarized light reflectance ratio R = s / p of a clean product is 3.0 or more. For this reason, in the apparatus of the present embodiment, when determining the degree of contamination based on the measured polarization reflectance ratio R = s / p, the contamination state is determined according to the material of the measurement target input in advance by the input device 22. Is changed, and in the case of sp metal, it is determined that contamination is caused when the polarization reflectance ratio R = s / p is 1.3 or less, and in the case of transition metal, the polarization reflectance is determined. When the ratio R = s / p is 3 or less, it is determined that contamination has occurred. As a result, an accurate determination can be made.

FIGS. 3A and 3B are diagrams for explaining another contamination determination method according to the present invention, in which a plurality of portions of sp metal and d metal (transition metal) having different cleanliness levels are shown. The results obtained by measuring the polarization reflectance ratio R = s / p in the above are plotted on the abscissa, where the polarization reflectance ratio R = s / p, and the ordinate, where the polarization reflectance ratio R = s / p is measured. It is a graph shown as a presence probability shown by the number.

In the case of the sp metal shown in FIG. 3A, the solid line L1 indicates the measurement result of the clean surface, the broken line L2 indicates the measurement result of the contaminated surface, and the dashed line L3 indicates the surface indicated by L2. The figure shows the measurement results of a more contaminated surface. Further, in the case of the d metal (transition metal) shown in FIG. 3B, the solid line L4 indicates the measurement result of the clean surface, the broken line L5 indicates the measurement result of the contaminated surface, and the dashed line L6 indicates the L value.
5 shows a measurement result of a surface further contaminated than the surface shown in FIG.

As shown, the theoretical value (1.3 in the case of sp metal, 1.3,
In the case of d-metal (transition metal), 3.0) is the most abundant and spreads around this. However, irrespective of the type of metal, the probability of reaching a theoretical value decreases as the degree of contamination increases, and the shape becomes gentle. This means that the contaminated surface widths W2, W4, which are the half widths of L2 and L5, compared to the clean surface widths W1 (about 0.15), W3 (about 0.5), which are the half widths of L1 and L4.
Is shown to be big.

Therefore, it is possible to determine whether or not contamination has occurred based on the half width when the graph as shown in FIG. 3 is created. This determination is made based on, for example, whether or not the half width exceeds 0.15 in the case of the sp metal and whether or not the half width exceeds 0.5 in the case of the d metal (transition metal). I just need. In this case, the degree of contamination can be determined based on the magnitude of the half-value width, and the above-described apparatus may perform such determination.

In the case of the above-described determination using the half-value width, it is necessary to measure a plurality of points on the sample and create a graph as shown in FIG. As described above, the clean surface has a steeper shape than the contaminated surface regardless of the type of metal. For this reason, at a position separated by a predetermined number from the theoretical value, for example, in the case of sp metal, the polarization reflectance ratio R = s / 0.3 which is approximately 0.3 away from the theoretical value 1.3.
When p is measured, in the case of d metal (transition metal), when the polarization reflectance ratio R = s / p, which is 0.5 away from the theoretical value of 3.0, is determined to be contaminated. Can be. In this case, the degree of contamination can also be determined based on the magnitude of the distance away from the theoretical value, and the above-described device may make such a determination.

[0057]

Since the present invention is configured as described above, it has the following effects.

It is possible to quickly observe the degree of contamination of the rough surface in the micron region, which has been difficult to observe conventionally, and to improve the production efficiency of electronic devices.

Since the contaminants are usually not uniformly distributed on the device surface, observing the surface distribution of the degree of contamination is an important means for specifying the contamination source. In addition, since the observation method and the analysis method of the present apparatus can generally observe changes in the microscopic state of the material surface, they are extremely effective when applied to research in material science.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

2A and 2B are diagrams illustrating an example of a measurement result according to the embodiment illustrated in FIG. 1; FIG. 2A illustrates Au contaminated by a resist material;
Is a graph showing changes in polarization reflectance ratio s / p from the pad, (b) organic and Fe ₂ O _3, lead relay contact portion contaminated with NiO polarization reflectance ratio (Rh member) s /
It is a figure showing change of p.

FIGS. 3 (a) and 3 (b) are diagrams for explaining another contamination determination method according to the present invention, in which a plurality of portions of sp metal and d metal (transition metal) having different cleanliness are used. The results of measuring the polarized light reflectance ratio R = s / p are plotted on the horizontal axis, where the polarized light reflectance ratio R = s / p, and the vertical axis is the number of locations where each polarized light reflectance ratio R = s / p was measured. 6 is a graph shown as the existence probability shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Light source 12 Beam expander 13 Condenser lens 14 Polarizer 15 Pinhole 16 Photodetector 17 XY stage 18 Control device 19 Output device 20 Stereo microscope 21 Sample 22 Input device

Claims (10)

[Claims] 1. The method according to claim 1, further comprising: comparing a ratio of a p-polarized light component to an s-polarized light component in a reflected light when a specific wavelength light is applied to a metal surface as a sample; A method for analyzing the degree of contamination of a metal surface, characterized by analyzing the degree of contamination. 2. A method according to claim 1, wherein said threshold value is varied according to the type of metal whose contamination is to be analyzed. 3. The method for analyzing the degree of contamination of a metal surface according to claim 2, wherein in the case of sp metal such as Au, Cu, or Al, the value obtained by removing the s-polarized component by the p-polarized component is 1.3 or less. A metal which is analyzed as contaminated when the transition metal surface is used, and is analyzed as contaminated when the value obtained by removing the s-polarized component by the p-polarized component is 3 or less in the case of a transition metal surface. Surface contamination analysis method. 4. The method according to claim 1, wherein the ratio of the p-polarized light component to the s-polarized light component in the reflected light when the specific surface of the metal surface is irradiated with the light of a specific wavelength is apart from a predetermined value by a predetermined distance. A method for analyzing the degree of contamination on a metal surface, comprising analyzing the degree of contamination of a metal. 5. The method for analyzing the degree of contamination of a metal surface according to claim 4, wherein the predetermined value and the predetermined distance are varied according to the type of the metal whose degree of contamination is to be analyzed. 6. The method for analyzing the degree of contamination of a metal surface according to claim 5, wherein in the case of sp metal such as Au, Cu, and Al, a predetermined value is set to 1.
3. A method for analyzing the degree of contamination of a metal surface, wherein the predetermined distance is 0.3, the predetermined value is 3.0 for a transition metal surface, and the predetermined distance is 0.5. 7. A light of a specific wavelength is irradiated to a plurality of portions of a metal surface as a sample, and the ratio of the p-polarized component to the s-polarized component in the reflected light is plotted on the horizontal axis, and the vertical axis is plotted for each polarization reflectance ratio R. A method for analyzing the degree of contamination of a metal surface, comprising: preparing a graph showing the existence probability indicated by the number of points where s / p is measured, and analyzing the degree of contamination of the metal surface by its half-value width. 8. A polarization analyzer for detecting a ratio of a reflected light of a p-polarized component and a reflected light of an s-polarized component when irradiating a metal surface as a sample with light of a specific wavelength; A stereo microscope for observing the metal surface, wherein the ellipsometer analyzes the reflection intensity R _os and R _op obtained while moving the sample by the XY stage to determine the thickness of the surface layer. And a dielectric constant of the surface layer represented by two-dimensional mapping. 9. The metal surface contamination degree analyzer according to claim 8, wherein the ellipsometer is configured to input light of a specific wavelength to the sample at an incident angle of 60 ° ± 10 °. Pollution degree analyzer. 10. The metal surface contamination degree analyzer according to claim 8, wherein a polarizing plate for extracting reflected light of the p-polarized component and the s-polarized component is provided on the reflected light side. An apparatus for analyzing the degree of contamination of a metal surface.