JPH11125602A - Method and device for analyzing foreign matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device that can automatically detect and analyze a minute, foreign matter on an object surface quickly and is suited for an in-line measurement in a semiconductor-manufacturing line or the like. SOLUTION: An object (a wafer 11) to be inspected is placed on an XY stage 21, the surface of the object (the wafer 11) is scanned by laser beams with a relatively large spot size (e.g. 1,000 μm) from a laser light source 33, and a foreign matter is detected and its approximate position is obtained. Then, the surface of the object (the wafer 11) is scanned by laser beam with a relatively small spot size (e.g. 10 μm) from the laser light source, and by utilizing laser light intensity distribution in a radius direction in laser beams, the accurate measurement position of the foreign matter is obtained at a more minute position accuracy than the spot size. Then, electron beams are scanned by a scanning-type electron gun 41 in an area near the accurate measurement position to observe a secondary electron image and a characteristic X ray, and the foreign object is analyzed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting and analyzing foreign matter adhering to the surface of an object, and more particularly to a semiconductor integrated circuit which can be introduced in-line into a manufacturing line when manufacturing a semiconductor device. The present invention relates to a foreign substance analysis method and apparatus used for detecting minute foreign substances attached to the surface of an object such as a semiconductor wafer or a semiconductor wafer, analyzing the shape and components thereof, and reducing the adhesion of the foreign substances.

[0002]

2. Description of the Related Art With the recent increase in the degree of integration of semiconductor integrated circuits, it is indispensable to increase the performance of the production technology and increase the reliability and yield, but these reliability and yield are affected. An important factor is a foreign substance adhering to the surface of a semiconductor integrated circuit or a semiconductor wafer during manufacturing. Between the amount of foreign matter adhered during production, whether the production line is operating stably, and the yield,
There is a close relationship.

In order to reduce the amount of foreign matter adhering to the surface during manufacturing, it is necessary to detect foreign matter during manufacturing, and to identify the foreign matter by analyzing the components, shapes and other characteristics of the detected foreign matter. There is a need to. However, the conventional foreign matter measuring apparatus does not have a function of analyzing the composition of the foreign matter, but simply measures the number of foreign matters, or has a long analysis time even if the composition analysis can be performed. The measurement device was not automated, and required position information by a particle counter, and was not practical for inline use. Hereinafter, a conventional foreign matter analyzer that detects and analyzes foreign matter attached to the surface of an object will be described with reference to FIG. In the following description, a semiconductor integrated circuit wafer is to be inspected.

In this conventional foreign matter analyzer, a wafer 11 to be inspected is placed, an XYθ stage 24 capable of moving the wafer 11 in both XY directions and rotating the wafer 11, and an optically removing foreign matter. Foreign matter inspection device 3 to detect
1, a scanning electron gun 41 used as an electron beam source,
An energy dispersive X-ray detector 42 for detecting X-rays from the wafer 11 irradiated with the electron beam and performing energy analysis, and a secondary electron detector for detecting secondary electrons from the wafer 11 irradiated with the electron beam 43, and all of these devices and components constituting the foreign substance analyzer are accommodated in a vacuum vessel (not shown). In the vacuum container, the foreign matter inspection device 31 and the scanning electron microscope 41 are disposed separately from each other, and an energy dispersive X-ray detector 42 is disposed near the scanning electron gun 41.
And the secondary electron detector 43 are arranged. Scanning electron gun 4
Reference numeral 1 denotes a device capable of scanning a certain area on the surface of an object by a finely focused electron beam, and includes an electron gun as an electron beam generating source, an electron lens system, an electron beam scanning system, and the like. . When the scanning electron gun 41 and the secondary electron detector 43 are combined, an ordinary scanning electron microscope (SEM) is configured.

The XYθ stage 24 is disposed at the bottom of the vacuum vessel, and is provided with a foreign matter inspection device 31 and a scanning electron gun 4.
1. The wafer 11 is placed below the detectors 42 and 43 in the XY directions.
Can be moved to position the wafer 11 at a position immediately below the foreign substance inspection device 31 or the scanning electron gun 41. X
Stage is provided with an X-direction encoder 22a for measuring the amount of movement in the X direction and a Y-direction encoder 22b for measuring the amount of movement in the Y direction.

The operation of detecting, observing, and analyzing foreign matter by the conventional foreign matter analyzer configured as described above will be described.

First, X is controlled by a drive control device (not shown).
Stage 24 is driven and controlled, and wafer 11 is arranged below foreign matter inspection device 31. Here, the fine particle inspection device 31 irradiates the surface of the wafer 11 with laser light while slightly moving the XYθ stage 24 in the X and Y directions, and scatters light caused by the fine foreign particles adhering to the surface to the laser light of the foreign material inspection device 31. Observation is performed by the detection unit to detect foreign matter attached to the surface. The readings of the X-direction encoder 22a and the Y-direction encoder 22b when detecting foreign matter on the surface of the wafer 11 indicate the surface position where the foreign matter is attached.

Next, the XYθ stage 24 is driven and controlled to place the wafer 11 below the scanning electron gun 41, and to refer to the surface position of the previously detected foreign matter to which XYθ
The stage 24 is slightly moved in the X and Y directions, and positioning is performed so that the attached foreign matter coincides with the focal point of electrons from the scanning electron gun 41. As a result, the foreign matter to be observed falls within the field of view of the energy dispersive X-ray detector 42 and the secondary electron detector 43. Here, by detecting the secondary electrons generated from the foreign matter by the electron beam emitted from the scanning electron gun 41 with the secondary electron detector 43, the external shape of the foreign matter can be observed. Similarly, the characteristic X generated from the foreign matter by the electron beam irradiated by the scanning electron gun 41
By detecting and analyzing the X-rays with the energy dispersive X-ray detector 42, the composition of the foreign matter can be X-ray analyzed.

The procedure for detecting and analyzing a foreign substance using a conventional foreign substance analyzer has been described above. The details are described in, for example, Japanese Patent Application Laid-Open No. 6-308039.

[0010]

The above-described conventional foreign matter analyzer is capable of detecting foreign matter adhering to the surface of an object, observing the outer shape of the detected foreign matter, and performing component analysis. The external shape observation operation and the component analysis operation require complicated operations by an operator, and are not suitable for use in a production line requiring high throughput or for automatic measurement. The reason is that the spot size of the laser light source used for detecting foreign matter in the foreign matter inspection device is significantly different from the spot size of the electron beam emitted from the scanning electron gun when analyzing foreign matter. No. For example, the spot size of a laser beam from a semiconductor laser is about 10 μm, and even if it is detected that there is a foreign substance within the range of the spot of the laser beam, the electron beam generally has a spot size of about 0.1 μm. Therefore, it is not easy to accurately irradiate a foreign substance with an electron beam. Further, if the XY stage is finely moved at the same pitch as the spot size of the electron beam to improve the positioning accuracy of the inspection object, it takes too much measurement time, which is not practical for in-line measurement. Further, it is rare that the surface of an object is always flat. For example, when the object surface is irradiated with a laser beam at an angle of 45 °, a foreign substance is found on a convex portion of 1 μm on the surface of the object. In this case, the error of the detected position is 1 μm. It is difficult to irradiate an electron beam having a diameter of about 0.1 μm to a position having a size of several μm only by an error due to irregularities on the surface of the object.

As described above, it is difficult to automatically irradiate the detection position of the foreign substance with the laser light source with the electron beam, and at present, the operator corrects the position while viewing the scanning electron microscope image. Is the fact.

An object of the present invention is to provide a method and an apparatus for analyzing foreign matter which can automatically detect and analyze minute foreign matter on the surface of an object in a short time and are suitable for in-line measurement in a semiconductor manufacturing line or the like. Is to provide.

[0013]

A foreign matter analysis method according to the present invention is a foreign matter analysis method for detecting and analyzing foreign matter present on the surface of an object to be inspected, wherein the foreign matter analysis method uses a laser beam having a first spot size. A first step of scanning the surface of an object to detect a foreign substance and obtaining an approximate position of the foreign substance, and a second spot smaller than the first spot size and having a laser beam intensity changing in a radial direction. A second step of scanning the laser light of the second spot size in the vicinity of the approximate position using the laser light of the size, and obtaining a precise measurement position of the foreign matter with a position accuracy higher than the second spot size; A third step of scanning the electron beam near the measurement position and analyzing foreign matter.

In this foreign matter analysis method, the third step includes analyzing the shape of the foreign matter by observing a secondary electron image and analyzing the component of the foreign matter by analyzing the energy of X-rays generated by the irradiation of the electron beam. Steps that include at least can be used. Further, the object is placed on the moving stage, and scanning of the laser light is performed in the first step and the second step by controlling the driving of the moving stage. In the third step, after positioning, the moving stage is moved. Scanning of the electron beam can be performed without moving.

The foreign substance analyzer according to the present invention is a foreign substance analyzer having a vacuum vessel for detecting and analyzing a foreign substance present on the surface of an object to be inspected, wherein the object is placed in the vacuum vessel. A first laser light source that irradiates an object with laser light at a first spot size;
A second laser light source for irradiating the object with laser light at a second spot size smaller than the first spot size, a laser detector for detecting laser light scattered by foreign matter on the surface of the object, and a surface of the object An electron gun for irradiating an electron beam, a secondary electron detector for detecting secondary electrons by the electron beam, and X generated by irradiating the electron beam.
An X-ray detector is provided for detecting a ray and measuring the energy of the X-ray, and an electron beam is applied to a position where the presence of a foreign substance is confirmed by irradiation of the object with a laser beam.

In the foreign matter analyzer of the present invention, the laser light from the first laser light source and the second laser light can be made coaxial. In this case, the first laser light source and the second laser light The laser light sources are combined so as not to change the mutual positional relationship, and are attached to the vacuum vessel so as to be integrally rotatable about an axis parallel to the moving plane of the positioning means as a rotation axis. Can be
Further, a plurality of combinations of the first laser light source and the second laser light source can be arranged in the direction in which the axis extends.

Further, in the foreign substance analyzing apparatus according to the present invention, the irradiation angle of the laser light from the first laser light source to the object and the second irradiation angle of the laser light are determined.
Irradiation angle of the laser light from the light source may be different, in that case, one of the irradiation angle of the laser light from the first laser light source and the irradiation angle of the laser light from the second light source to the object, The irradiation angle of the electron beam to the object may be the same.

Further, in the foreign substance analyzer of the present invention, the irradiation position of the laser beam from the second laser light source and the irradiation position of the electron beam in the vacuum vessel can be made the same.

In the present invention, a plurality of laser light sources to be used for foreign object detection are prepared by changing the spot size of the laser light, and the detection time is increased and the position accuracy is improved. First, the entire surface of the object surface is scanned with a light source having a large spot size, and the outline of the position of the foreign substance existing on the surface is grasped. Then, the foreign substance is present using a light source having a small spot size. By measuring only the portion with high accuracy, it is possible to realize a high speed and an improvement in position accuracy. At this time, if the smaller spot size is, for example, 10 μm, the intensity of the laser beam is not uniform among the spot sizes, but has a Gaussian distribution that is strong at the center and weak at the periphery. For this reason, the position of the foreign matter can be obtained with higher precision than the smaller spot size.

Further, when the surface of the object to be inspected has irregularities, there is an error caused by the irradiation angle, and the detection positions from the light sources having different irradiation angles do not match. In the present invention, this discrepancy may be positively used to correct the error in the detection position based on the difference between the disparity distance and the irradiation angle. Further, in the present invention, it is desired to analyze information on the position of the foreign substance on the surface of the object (information on the position where the foreign substance is present, information on a portion where the foreign substance is likely to be present, and analysis on the object). It is also possible to store in advance a part of the information on a recording medium or the like, read this information from the recording medium, and automatically detect and analyze a foreign substance.

[0021]

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

<< First Embodiment >> FIG. 2 is a perspective view showing a configuration of a foreign substance analyzer according to a first embodiment of the present invention. Here, a description will be given with a semiconductor integrated circuit wafer as an inspection target.

The wafer 11 to be inspected is placed on an XY stage 21 which can move the wafer 11 in both the XY directions. The XY stage 21 is provided with an X-direction encoder 22a for measuring the movement amount and position in the X direction and a Y-direction encoder 22b for measuring the movement amount and position in the Y direction. Instead of the encoders 22a and 22b, the position may be measured by a laser interferometer. The XY table 21 is disposed in a vacuum vessel (not shown) at the bottom of the vacuum vessel. The vacuum vessel has a laser light source 32 as a light source of a laser beam having a small spot size (for example, 10 μm), and a spot light source. A laser light source 33 which is a light source of a laser beam having a large size (for example, 1000 μm), a scanning electron gun 41 used as an electron beam source, and an energy dispersive type which detects X-rays from the wafer 11 irradiated with the electron beams. An X-ray detector 42 and a secondary electron detector 43 for detecting secondary electrons from the wafer 11 irradiated with the electron beam are provided. The laser light from the laser light source 32 and the laser light from the laser light source 33 are provided. The laser light sources 32 and 33 are arranged so as to be coaxial with each other and hit the same location on the wafer 11 at the same angle. The laser beam having a large spot size and the laser beam having a small spot size may be selectively irradiated to the wafer 11 by using one laser light source and adjusting the aperture in the optical system. The scanning electron gun 41 is, for example, a scanning electron gun capable of scanning the surface of the wafer 11 with an electron beam which is narrowed down in a region of several μm square in the same manner as described in the related art.

In the vacuum vessel, laser light sources 32, 3
3 and the scanning electron gun 41
The position where the electron beam is irradiated from the XY stage 2 is changed by a control driving device (not shown).
Driving 1 moves between these two positions and is positioned at a predetermined irradiation position.

Next, the operation of detecting and analyzing a foreign substance using the foreign substance analyzing apparatus will be described.

First, XY by a control driving device (not shown).
While moving the stage 21 in the X and Y directions, the wafer 11 is irradiated with laser light from a laser light source 33 having a large spot size. The XY stage 21 is moved so that the laser light can scan the entire surface of the wafer 11, and the X-direction encoder 2 when the scattered light from the foreign matter is observed by the laser detector 34.
2a and the reading of the Y-direction encoder 22b are stored each time scattered light is detected. At this time, if the spot size of the laser light source 33 used is as large as about 1000 μm, and the moving pitch of the stage is also set at 1000 μm, the time required to move the entire surface of the wafer 11 is about 1 to 2 minutes. A map can be obtained at high speed (in this example, the mesh of the foreign matter detection map is 1000 μm). However, although the entire surface of the wafer 11 can be inspected at high speed, the detected foreign matter is 1000 μm × 100
Within the range of 0 μm, it is not known where it is located.

Next, the laser light source 33 is turned off, and the laser light source 32 having a small spot size (for example, about 10 μm) is turned off.
The laser beam is applied to the wafer 11. The XY stage 21 is moved so that the laser beam can scan the area of 1000 μm × 1000 μm on the wafer stored earlier,
X-direction encoder 22a and Y-direction encoder 22b when scattered light from a foreign substance is observed by laser detector 34
Is memorized again. At this time, the XY stage 21
Is set to 10 μm, which is about the same as the spot size of the laser light source 32, the time for moving in the range of 1000 μm × 1000 μm is about 30 seconds. At this stage, the detected foreign matter is located within a range of 10 μm × 10 μm.

Next, a laser beam is irradiated from the laser light source 32 to the foreign substance positioned within the range of 10 μm × 10 μm, and the moving pitch of the XY stage 21 is set to 1 μm. Even if the spot size of the laser light source 32 is 10 μm, generally, the intensity distribution of the laser light is not constant within this spot, but has a certain distribution (Gaussian distribution).
The more you go to the center, the stronger the strength. Therefore, if the XY stage 21 is stopped when the intensity of the scattered light from the foreign substance observed by the laser detector 34 is maximized, 1 μm ×
Foreign matter can be positioned within the range of 1 μm. 1
The time required to move a range of 0 μm × 10 μm at a pitch of 1 μm is about 3 seconds.

By the above operation, the detected foreign matter can be positioned within a range of 1 μm × 1 μm. The scanning electron gun 41 is applied to this 1 μm × 1 μm range.
By irradiating and scanning with an electron beam, the component analysis within this range can be performed in about one minute using the energy dispersive X-ray detector 42. Further, if secondary electrons generated together with characteristic X-rays by electron beam irradiation are detected by the secondary electron detector 43, a secondary electron image (that is, a scanning electron microscope image) can be obtained.

By the above operation, foreign substance detection and analysis on the wafer can be performed at high speed (for example, when foreign substance
If there are, the analysis can be performed automatically (within 10 minutes until the analysis result is obtained) (there is no element for which the operator has to make a decision in the above operation).

<< Second Embodiment >> Next, a second embodiment of the present invention will be described.
An embodiment will be described. FIG. 3 is a perspective view showing the configuration of the foreign substance analyzer according to the second embodiment.

The foreign substance analyzer according to the second embodiment has the structure shown in FIG.
Although the foreign matter analyzer of the first embodiment described above has almost the same configuration using the laser light source, the laser light emitted from the laser light sources 32 and 33 can be scanned in any one direction. Differs in that That is, in the first embodiment, the laser light sources 32 and 33 are fixed to the vacuum vessel, whereas in the second embodiment, the laser light sources 32 and 33 do not change the mutual positional relationship. The laser light sources 32 and 33 are attached to a vacuum container so that the combination of these laser light sources 32 and 33 can rotate around an axis parallel to the XY plane with one point as a support point.
With this configuration, each of the laser light sources 32, 3
The laser light from 3 draws a scanning line 35 on the wafer 11, and if the detection of foreign matter is performed while scanning the upper surface of the wafer 11 in one direction with such a laser light, it is necessary to detect the foreign matter. Time can be reduced. In the second embodiment, by arranging a plurality of laser light sources 32 and 33 in a line in the direction in which the rotation axis extends, the time required for scanning the upper surface of the wafer 11 can be reduced by a combination of the laser light sources. (The combination of the laser light source 32 and the laser light source 33) can be shortened in inverse proportion to the number.
The detection and analysis of a foreign substance in the second embodiment is performed in accordance with the first embodiment.
This is performed in the same manner as in the embodiment.

<< Third Embodiment >> Next, a third embodiment of the present invention will be described.
An embodiment will be described. FIG. 4 is a perspective view showing the configuration of the foreign substance analyzer according to the third embodiment.

The foreign substance analyzer according to the third embodiment is similar to that shown in FIG.
The configuration is almost the same as that of the foreign substance analyzer of the first embodiment described above, except that the irradiation angles of a plurality of laser light sources to be used on the object (the wafer 11 in this case) are respectively changed. . That is, in the first embodiment, the laser light sources 32 and 33 viewed from the object (wafer 11) are used.
Are the same, but in this embodiment, the laser light from the laser light source 32 irradiates the wafer 11 at an angle θ ₁ and the laser light from the laser light source 33 irradiates the wafer 11 at an angle θ _2. Each of the laser light sources 32 and 33 is attached to a vacuum container.

Generally, as the manufacturing process of a semiconductor integrated circuit wafer progresses, wiring and films formed on the surface of the wafer become more complicated, so that the surface irregularities become more conspicuous. Therefore, for example, as shown in FIG.
When the foreign matter 12 is present in a portion having a thickness of t on the surface, there is a displacement of Δx _{1 in the} detection by the laser light source 32 and Δx _{2 in the} detection of the laser light source 33 as compared with the case where there is no convex portion. Same foreign object 1 of two laser light sources 32 and 33
When the irradiation angle is changed to θ ₁ and θ ₂ respectively, when the foreign matter 12 is on the convex portion, Δx (= Δx
₂ −Δx ₁ ) is observed. Here, the observed △
From x and the known angles θ ₁ and θ ₂ , the position where the electron beam is actually irradiated by the scanning electron gun 41 from the foreign matter detection position by the laser light is corrected (△ x ₁ from the detection position of the laser light source 32). △ x ₂ ) from the detection position of the laser light source 33. The calculation will be described below.

The relational expression between the positional shift Δx ₁ by the laser light source 32, the irradiation angle θ ₁ and the thickness t of the surface convex portion is given by the following expression.

Tan θ ₁ = t / △ x ₁ (1) Similarly, the relational expression between the displacement Δx ₂ by the laser light source 33, the irradiation angle θ ₂ and the thickness t of the surface convex portion is given by the following expression. Can be

Tan θ ₂ = t / △ x ₂ (2) On the other hand, the observed shift Δx can be expressed by the following equation.

△ x = △ x _2- △ x ₁ (3) The correction value from the detection position using the laser light source 32 is △ x ₁
The correction value from the detection position using the laser light source 33 is Δx ₂ , and each correction value can be obtained by eliminating t from the above equation.

Δx ₁ = Δx · tan θ ₂ / (tan θ ₁ −tan θ ₂ ), Δx ₂ = Δx · tan θ ₁ / (tan θ ₁ −tan θ ₂ ) (4) scanning type Assuming that the electron beam from the electron gun 41 irradiates the wafer 11 almost vertically, the above-described correction values Δx ₁ and Δx
_It is sufficient to correct the position of the foreign substance based on ₂ and
If the irradiation angle of the electron beam from the scanning electron gun 41 and the irradiation angle of the laser light source 32 having the smaller beam spot are the same, the detection position of the laser light source 32 and the laser light source 3
The deviation Δx from the detection position due to 3 becomes the correction value as it is.

Although the embodiments of the present invention have been described above, in each of the above-described embodiments, foreign substance detection using a laser beam and foreign substance analysis using an electron beam are performed at different places in a vacuum vessel. ing. Since the scanning range by the electron beam is minute, high accuracy is required for the position reproducibility of the XY stage 21. For example, if the scanning range of the electron beam is 1 μm × 1 μm, a high accuracy of 1 μm or less is required for the position reproducibility of the XY stage 21. The stage 21 may need to be moved slowly. On the other hand, if each device is installed so that the laser beam irradiation position and the electron beam irradiation position of the object are the same, without separating the foreign matter detection portion by the laser beam and the foreign matter analysis portion by the electron beam in the vacuum vessel, the measurement time can be reduced. Can be kept fast.

In each of the above-described embodiments, the description has been made with an overall inspection of a semiconductor wafer in mind. However, coordinate data and foreign substance size data obtained as a result of measurement by another foreign substance detection device, and the presence of foreign substances If it is possible to recognize in advance the data that is likely to be present, and especially the data of the part that you want to analyze on the object, through a recording medium such as a magnetic disk, foreign matter analysis can be performed even faster. Can be performed automatically.

Further, in the present invention, the method of analyzing foreign matter on the surface of an object is not limited to the method of analyzing characteristic X-rays generated by electron beam irradiation with an energy dispersive X-ray detector. It is good also as a structure which performs a spectroscopic analysis. In each of the embodiments described above, the shape of the foreign substance is observed by observing the secondary electron image. However, when the degree of vacuum in the vacuum vessel is as low as about 10 Pa, the observation is performed using the backscattered electron detector. If an image is obtained, substantially the same effect as in the case described above can be obtained.

[0044]

As described above, according to the present invention, the detection, observation, and component analysis of a foreign substance adhering to the surface of an object can be performed easily or automatically, thereby enabling semiconductor device manufacturing. In a process line or the like, there is an effect that it is possible to easily detect and analyze a foreign substance and to grasp the shape thereof in a short time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a conventional foreign substance analyzer.

FIG. 2 is a perspective view showing a configuration of a foreign substance analyzer according to the first embodiment of the present invention.

FIG. 3 is a perspective view illustrating a configuration of a foreign substance analyzer according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a configuration of a foreign substance analyzer according to a third embodiment of the present invention.

FIG. 5 is a diagram for explaining a third embodiment.

[Explanation of symbols]

 Reference Signs List 11 wafer 12 foreign matter 21 XY stage 22a X-direction encoder 22b Y-direction encoder 24 XYθ stage 31 Foreign matter inspection device 32 Laser light source (light source with small spot size) 33 Laser light source (light source with large spot size) 34 Laser detector 35 Laser light source Scanning line 41 Scanning electron gun 42 Energy dispersive X-ray detector 43 Secondary electron detector

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/66 H01L 21/66 L (72) Inventor Koji Honma 2-703 Tachino, Higashiyamato-shi, Tokyo Inside Chemitronics Co., Ltd. ( 72) Inventor Masayoshi Tsuchiya 871-8 Tokaichiba-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Sigma Tech Co., Ltd.

Claims (12)

[Claims] 1. A foreign matter analyzing method for detecting and analyzing foreign matter present on the surface of an object to be inspected, wherein the foreign matter is detected by scanning the surface of the object using a laser beam having a first spot size. A first step of obtaining a rough position of the foreign matter, and using the laser light of a second spot size smaller than the first spot size and having a laser light intensity changing in a radial direction, Is scanned with the laser light of the second spot size in the vicinity of the second spot size, and the second measurement position of the foreign matter is obtained with higher positional accuracy than the second spot size.
And a third step of scanning the electron beam near the precise measurement position to analyze the foreign matter. 2. The method according to claim 1, wherein the third step includes at least analyzing the shape of the foreign matter by observing a secondary electron image and analyzing the component of the foreign matter by analyzing the energy of X-rays generated by the irradiation of the electron beam. The foreign matter analysis method according to claim 1, wherein the method includes: 3. The step of placing the object on a moving stage and controlling the driving of the moving stage to perform scanning of the laser light in the first and second steps, and the third step 3. The method according to claim 1, wherein after the positioning, the scanning of the electron beam is performed without moving the moving stage. 4. A foreign matter analyzing apparatus having a vacuum container, for detecting and analyzing foreign matter present on the surface of an object to be inspected, wherein the object is placed and positioned in the vacuum container. Means, a first laser light source for irradiating the object with laser light at a first spot size, and a second for irradiating the object with laser light at a second spot size smaller than the first spot size. A laser light source, a laser detector for detecting laser light scattered by foreign matter on the surface of the object, an electron gun for irradiating the surface of the object with an electron beam, and a secondary for detecting secondary electrons by the electron beam. An electron detector for detecting X-rays generated by irradiating the electron beam and measuring the energy of the X-rays;
A foreign matter analyzer, comprising: a line detector; and irradiating the electron beam to a position where the presence of the foreign matter is confirmed by the irradiation of the laser light onto the object. 5. The foreign matter analyzer according to claim 4, wherein the laser light from the first laser light source and the second laser light are coaxial. 6. The first laser light source and the second laser light source are combined so as not to change a mutual positional relationship, and an axis parallel to a moving plane of the positioning means is used as a rotation axis. The foreign substance analyzer according to claim 5, wherein the foreign substance analyzer is attached to the vacuum container so as to be able to rotate integrally. 7. The foreign matter analyzer according to claim 6, wherein a plurality of combinations of the first laser light source and the second laser light source are arranged in a direction in which the axis extends. 8. The foreign matter analyzer according to claim 4, wherein an irradiation angle of the laser light from the first laser light source to the object is different from an irradiation angle of the laser light from the second light source. 9. An irradiation angle of a laser beam from the first laser light source to the object and an irradiation angle of a laser beam from the second light source are the same as an irradiation angle of the electron beam to the object. A foreign matter analyzer according to claim 8. 10. The foreign matter analyzer according to claim 4, wherein the irradiation position of the laser beam from the second laser light source and the irradiation position of the electron beam in the vacuum vessel are the same. 11. A rough position of the foreign matter is obtained by using a laser beam from the first laser light source, and then the second position is obtained.
11. A precise measurement position of the foreign matter is obtained with a position accuracy higher than the second spot size by using a laser beam from the laser light source, and irradiation of the electron beam is performed based on the precise measurement position. 2. The foreign substance analyzer according to claim 1. 12. The foreign matter analyzer according to claim 4, wherein information on a position of the foreign matter on the surface of the object is provided, and the foreign matter is detected and analyzed based on the information.