JPH0238951A - Device and method for foreign matter detection - Google Patents

Abstract

PURPOSE:To light the surface of a body to be measured linearly without providing any movable part and to shorten an inspection time by providing an oblique light optical system with a linear optical system. CONSTITUTION:The oblique lighting system 5a lights the surface of the sample 7 slantingly above 18 to form a linear spot 8. The detection system consisting of an image forming lens 9, a light shielding plate 10, and a detector 11 is provided vertically and the linear spot 8 and the light receiving surface of the detector 11 are in image formation relation by the image forming lens 9; if there is foreign matter in the linear spot 8, scattered light is generated and its image is projected on the detector 11 and detected. The sample 7 on a stage 12 is moved at equal speed by a motor 13 and a feed screw 14 and inspected. The electric signal 11a from the detector 11 is processed by a binarization circuit 15 and an arithmetic circuit 16 and when the foreign matter is detected, its coordinates are displayed on a foreign matter display part 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to glass substrates such as masks and reticles used in exposure apparatuses, wafers, and printed circuit boards.

Device and method for detecting foreign matter on the surface of a sample such as a magnetic disk etc. f:
Regarding.

[Conventional technology]

Conventionally, foreign matter '4! on a semiconductor wafer! As for the ltX device, De R Osward: Laser Scan Technique Photoelectronics Materials Surface Evalian Engine, Scieoff Electronics Materials Volume 6 No. 1 1974-1CDIIRIIO,
? Watd', ALαzgr ScarLTgchni
qug j'or.

Electronic Matgrialgz Stb
rfacgEvaluation, I.

of E1gctron number cz MatgrLaltz
, Vol. 5. Itl 1974-1) etc.

These principles are shown in FIGS. 16-18. The epi-illumination optical system includes a laser light source 40. Condensing lens 41, 1 optical prism 4
2. Field lens 43. It consists of a /4 wavelength plate and a 44° objective lens 45.

The detection optical system includes a light shielding plate 47. Imaging lens 48. Detector 49
Consists of. Next, a[ of each part will be explained in detail.

In Figure 17, laser light 50 output from the laser light source 40 is S-polarized light, passes through a polarizing prism 42,
A laser spot 50α is formed within the aperture 43cL of the field lens 43. The laser beam 50 that has passed through the field lens passes through a 4tfIL long plate 44 and forms a laser spot 50c on a sample 46 by an objective lens 45.

When there is no foreign matter on the sample 46, the laser reflected light (source of 0th order diffraction) 50 from the sample surface is redirected to the objective lens 45. / [Long board 44. Passes through the field lens 43,
After being 100% reflected by the polarizing prism 42, the light is blocked by the light blocking portion 47cL of the light blocking plate 47. Here, the field lens 43 controls the width 5 of the laser beam 50 at the aperture 45α.
0k is projected onto the light shielding portion 47α.

The Eft plate 47 is formed by, for example, attaching an opaque material to the center of a transparent glass plate to form a light shielding part 47α.

Here, the laser illumination light 50 passes through the 1/1L long plate 44,
Further, when the laser reflected light 50 passes through, the S-polarized light of the illumination light 50 becomes P-polarized KK in the reflected light 50, so that the reflected light 50 is reflected 100 times by the polarizing prism 42.

As shown in FIG. 18, when a foreign object 52 is present on the sample 46, when the illumination light 50 irradiates the foreign object 52, the foreign object 52
Scattered light (higher-order diffracted light) 51 is generated from 2, spreads over the entire surface within the aperture 45α of the objective lens 45, and returns along the same optical path as the reflection t50 described above.

Since the surface of the foreign object 52 has minute irregularities, the polarization components of the scattered light 51 include both S and P. Scattered light from foreign matter 5
After being reflected by the polarizing prism 42, the P-polarized light component 51A of 1 passes through the transparent part outside the light shielding part 47α of the light shielding plate 47, and is focused on the detector 49 by the imaging lens 48 so that it is detected. It had become.

Another known example is JP-A-57-128854. The above-mentioned conventional technology does not take into account the following points:
There was a problem with the performance of the foreign object inspection device.

1) Conventional mechanical deflectors use a contact agent at the joint between the mirror and the mirror rotation axis, which causes problems such as low reliability and failure to follow drive signals due to the mirror's own moment of inertia. No consideration was given to this, and there was a limit to the scanning speed of the laser beam, making it impossible to shorten the inspection time.

2) Since the laser beam was irradiated onto the sample surface through the field lens and objective lens, a small amount of stray light reflected on the lens surface changed its polarization direction from linear to elliptically polarized light due to the curvature of the lens surface, and the light shielding plate The foreign object passes through the outside of the light shielding part and is delayed to the detector, reducing the accuracy of foreign object detection.

3. Since the laser spot of the illumination light is point-shaped, it is necessary to provide a laser scanning means C (figure omitted) in the optical path of the epi-illumination optical system in order to scan the sample two-dimensionally, which increases the complexity of the optical system. I was invited.

A first object of the present invention is to provide a method and apparatus for inspecting foreign matter that solves the above problems and shortens the time required to detect foreign matter.

A second object of the present invention is to provide a foreign object inspection method and apparatus that improve the SIN ratio for foreign object detection.

The purpose of the straw 3 of the present invention is to obtain the above M1 which has been converted into a device configuration.
The purpose of this is to provide a foreign object detection device equipped with a linear optical system including a lens that condenses a light source image into a linear shape and a lens that magnifies and projects this layered light source image onto the surface of an object to be inspected from an obliquely upward direction. an oblique illumination optical system, a condenser lens that images the reflected light from the surface of the object to be inspected onto a one-dimensional solid-state image sensor, and a condenser lens that focuses the reflected light from the surface of the object to be inspected and the circuit pattern on the surface of the object to be inspected. This is achieved by using a detection optical system equipped with a reducing means that blocks reflected light from the

The purpose of Wc2 and straw 5 is to convert illumination light, such as laser light, into a linear spot using an optical system using a condensing lens and a cylindrical lens, and then use a half mirror to convert the illumination light, such as laser light, into a linear spot on the object to be inspected. Epi-illumination is applied to the surface from above. At this time, ensure that the illumination light does not pass through the imaging lens for detecting foreign objects and illuminate the surface of the object to be inspected.
-7 mirror is installed between the imaging lens and the object to be inspected. In addition, the reflected light from within the linear illumination area on the surface of the object to be inspected is detected using an imaging lens and a one-dimensional solid-state image sensor, and the specular reflection light of the illumination light from the surface of the object to be inspected and the reflected light from the circuit pattern are detected. A shield placed between the imaging lens and the one-dimensional solid-state image sensor
This is achieved by blocking light with ``/l, #L and effectively detecting only the light scattered by foreign objects.

In addition, the present invention uses two systems, an oblique illumination optical system having a linear optical system and an epi-illumination optical system having an icy optical system, in a foreign matter inspection apparatus, and uses two systems to direct reflected light from a sample to a one-dimensional solid-state image sensor. The purpose of the present invention is to incorporate a detection optical system having a condensing lens that performs an upper Kl image, and a light-shielding optical system that blocks specularly reflected light from a sample and light reflected from a circuit pattern on the sample.

[Effect]

In a foreign object detection device, illumination light is converted into a linear spot by an optical system using a condenser lens, a cylindrical lens, etc. In addition, epi-illumination is applied to the surface of the object to be inspected using a half mirror installed between the imaging lens and the object to be inspected. This trap eliminates the reflection of illumination light on the M-image lens surface and prevents stray light from reaching the one-dimensional image sensor, greatly improving the s7y of foreign object detection. Compared to conventional spot scanning, inspection time can be shortened and foreign objects can be detected stably.

In addition, in the horizontal extraction device, by providing a linear optical system in the oblique illumination optical system, the image of the light source becomes a linear light beam on the surface of the object to be inspected. From this K, galvano mirror
By using a deflector such as the above, it is possible to direct illumination in a narrow pattern on the surface of the object to be inspected without performing spot-on inspection, and the inspection time can be shortened.

In addition, in the foreign matter calibration device k, 1) Incorporate a linear optical system into the oblique illumination optical system.

As a result, the light from the light source becomes linear on the sample. Thereby, spot scanning, ie.

There is no need to use a deflector such as a valvanometer mirror, so it is less susceptible to vibrations and inspection time can be shortened.

2) By adding an epi-illumination optical system, the main component of the reflected light from the sample enters the detection optical system, and the S/N ratio is significantly improved compared to oblique illumination.

In addition, the fishing depth in the detection direction of the sample with respect to the focal position of the irradiation light is shown in Figure 11 (α)K as shown in Figure 11 1b+.
Because it is larger compared to the oblique lighting shown.

It is possible to detect foreign substances on substrates with low flatness such as printed circuit boards.

[LOL example]

An embodiment of the present invention will be described below.

Figure i@1 shows the difference v! according to the present invention. The general configuration of the J detection device is shown. Here, the sample 7 is assumed to be a glass substrate such as a mask or reticle containing a circuit pattern, a wafer or a printed circuit board, or a Mi disk.

The oblique illumination system 5a includes light sources 1. Coming lens 21 cylindrical lens 5. Take it from the illumination lens 4 and point the surface of the sample 70 diagonally upward 18
(θ=10 to 80 degrees) to form a Km-shaped spot 8 on the sample surface. On the other hand, in the vertical direction of this linear spot 8, an M image lens 9. Light shielding plate 10. A detection system consisting of a detector 11 is arranged, and a linear spot 8 on the surface of the sample 7 and the light receiving surface of the detector 11 are in an imaging relationship by an imaging lens 9. As a result, a foreign object C (not shown) existing within the linear spot 8 generates scattered light due to the illumination light, and its image is projected onto the detector 11 and detected. The detector 11 used here is, for example, a COD
, a self-scanning accumulation type one-dimensional solid-state image sensor such as a photodiode play.

The sample 7 is fixed on a stage 12 and moved at a constant speed in the X direction by a motor 16 and a feed screw 14 for inspection. During calibration, the electrical signal 11α from the detector 11 is sent to the 211m conversion circuit 15. Processed at any time by the arithmetic circuit 16, when detecting foreign matter,
The detection signal is sent to the foreign object display section 17, and the coordinates of the foreign object position are stored. Thereby, it is also possible to display and confirm the position of foreign matter on the sample 7 after the inspection is completed.

Next, the configurations of the illumination system and detection system will be described with reference to FIGS. 2 and 5. First, illumination heat will be explained with reference to FIG.

The light source 1 oscillates, for example, a condensing laser beam 23, and after passing through the condensing lens 2, the laser beam 23 becomes a parallel beam of light, passes through the cylindrical lens 3, and reaches point E (focal position of the cylindrical lens).
After passing through the illumination lens 4, a KM-shaped spot 8 is formed on the surface of the sample 7. Point E and the surface of the sample 7 are both at the focal point of the illumination lens 4.

On the other hand, in the detection system shown in the fifth factor, the specularly reflected light 24 of the illumination light on the surface of the sample 7 passes through the imaging lens 9 and then forms a linear spot 24α again at one point (focal position of the imaging lens). However, the light is blocked by the light shielding plate 10 and the button is designed so that the light does not reach the light receiving surface of the detector 10.

In addition, reflected light (diffraction light) from the edges of the circuit pattern on the surface of the sample 7 is also blocked by the light shielding plate 10, but the light scattered by foreign objects passes around the light shielding part of the light shielding plate 10 and is detected by the detector 10.
reaches the light receiving surface and is detected.

FIG. 4 shows an example of the circuit pattern on the sample 7, and FIG. 5 shows the shape of the light shielding plate 10. The fifth factor (α) is used for inspecting the surface of the sample 7 on which no circuit pattern exists, and has the function of blocking specularly reflected light of illumination light from the sample surface. In addition, for the circuit patterns in Figure 4 (turns 25 and 26 K, use a light shielding plate in the shape of Figure 5 (bl), and for circuit patterns with inclined corners, use a light shielding plate in the shape of Figure 5 (CL). In any case, when using these several shapes of light shielding plates, for example, as shown in FIG. 6, the turret 21
A light shielding plate 10 of each shape is installed on the turret 2.
It is also possible to provide a rotation mechanism in 1 and switch by rotating. Furthermore, if it is necessary to change the shape of the light-shielding plate at any time, it may be possible to memorize the shape of the light-shielding pattern in advance and operate it at high speed using a liquid crystal printer or the like.

If sample 7α is rectangular as shown in No. 7l-), sample 7
Zigzag feed α in the x and y directions. In the same figure (when the sample 7b is circular like Al, the sample 7b is spirally fed in the θ direction with the longitudinal direction of the linear spot 8 aligned with the radial direction of the sample 7b. Also, both sides of the sample 70 are If the inspections are to be performed simultaneously, two sets of similar foreign object detection devices 29 may be installed on both surfaces* of the sample 7, as shown in FIG.

As described above, according to this embodiment, it is possible to stably detect microscopic foreign objects present on the surface of a glass mask, 8-air disk, etc.

Next, another embodiment of the present invention will be described with reference to the accompanying drawings.

First, a general configuration of a foreign object detection device according to the present invention will be explained with reference to FIG. The sample 7 is assumed to be a glass substrate such as a mask or reticle containing a circuit pattern, a wafer, a printed circuit board, or an 8-chip disk.

The epi-illumination system 5b includes a light source, a condensing lens 22, and a cylindrical lens 3.
．． Lighting lens 4. It consists of a half mirror 6, illuminates the surface of the sample 7 from above 19, and illuminates the sample surface [il-shaped spot 8].
form. On the other hand, above this patterned spot 8,
Imaging lens 9. Light shielding plate 10. A detection system consisting of a detector 11 is arranged, and the linear spot 8 on the surface of the sample 7 and the light receiving surface of the detector 11 are in an imaging relationship by an imaging lens 9. As a result, a foreign object (not shown) present within the linear spot 8 emits scattered light due to the illumination light, and its image is projected onto the detector 11 and detected.

The detector 11 is, for example, a one-dimensional solid-state solid-state device of a self-scanning accumulation type, such as a COD or a photodiode play.

The sample 7 is fixed on the stage 12 and moved at a constant speed in the X direction by the motor 15 and the feed screw 14 for inspection. During the inspection, the signal 11α from the detector 11 is transmitted to the binarization circuit 15.
．． It is processed by the arithmetic circuit 16 as needed, and when a foreign object is detected, a signal is sent to the foreign object display section 17, the coordinates of the foreign object position are stored, and mapping of the foreign object can be displayed after the inspection is completed.

FIG. 10 shows a partial configuration of the epi-illumination system. In the epi-illumination/detection system, when the No'-7 mirror 6 is installed above the imaging lens 9 as shown in FIG. 10 (α), when the surface of the sample 7 is illuminated with illumination light A or C, the imaging lens 9 Reflected light B or D is generated on the lens surface and becomes stray light to the detection system.
A half mirror 6 is installed below the imaging lens 9 to provide epi-illumination of the sample 7. Figure 11, 5
The illumination system and detection system will be explained in detail using figures. First of all
The illumination system will be explained with reference to FIG.

The light source 1 emits, for example, a laser beam 23 with good convergence,
It becomes a parallel light beam at the condenser lens 2, passes through the cylindrical lens 3, and forms a linear spot 23α at point E (focal position of the cylindrical lens).
become. Furthermore, the illumination lens 4. A VC spot is formed on the surface of the sample 7 through the half mirror 6. Point E and the sample surface are both at the focal point of the illumination lens 4. - In the detection system, the reflection on the surface of the sample 7 [24 passes through the imaging lens 9 and becomes a linear spot 24α again at point F (focal position of the M image lens), but this is caused by the light shielding plate 10. It is shaded.

It does not reach the light receiving surface of the detector 10. Further, reflected light (diffraction light) from the pattern is also blocked by the light shielding plate 10, but scattered light from foreign objects passes through the outside of the light shielding part of the light shielding plate 10 and is detected by the detector 1.
01C detected.

FIG. 4 shows an example of the circuit pattern on the sample 7, and FIG. 5 shows the shape of the light shielding plate 10. (αl in FIG. 5 is used to inspect the surface of the sample 7 where no circuit pattern exists on the sample, and has the function of blocking specularly reflected light of the illumination light from the sample surface. Also, the circuit pattern 25 which is the fourth factor) , 26 uses a light-shielding plate in the shape of FIG. When using a light shielding plate, for example, as shown in FIG. 6, it is also possible to install light shielding plates 10 of each shape on the turret 21, and provide the turret 21 with a rotation mechanism so that the light can be switched by rotating. Furthermore, if it is necessary to change the shape of the light-shielding plate at any time, it may be possible to use a liquid crystal shutter or the like to operate the light-shielding pattern shape stored in advance at high speed.

When the sample 7α is rectangular as shown in FIG. 7 (α1), the sample 7α is fed in a zigzag manner in the is aligned with the radial direction of the sample 7b, and the sample 7b is spirally fed in the θ direction by 5°. When inspecting both sides of the object 7 at the same time, a similar foreign object detection device 2 is used as shown in Fig. 8.
It is advisable to install two sets of 9 on both sides of the sample 7.

As explained above, according to this embodiment, it is possible to stably detect minute foreign particles present on the surface of a glass mask, magnetic disk, etc.

Another embodiment of the present invention will be explained with reference to FIG. First, in the epi-illumination detection system 5b, the light source 1 emitted from the linear optical system 20. A sample 7 is illuminated in a linear form 8 through a half mirror 6. The reflected light from the sample 7 passes through the bar 7 mirror 6 and is imaged onto the one-dimensional solid imaging probe 11 by the condenser lens 2. One-dimensional solid M! 1 Yoshiko 11
The signal from the binarization circuit 15. It is displayed on the foreign object display section 17 via the arithmetic circuit 16. In addition, the oblique illumination detection thread 5α
In this case, light emitted from a light source 1 passes through a linear optical system 20 and illuminates a sample 7 in a linear form 8 . Similar to the epi-illumination detection system, the reflected light from the sample 7 is transmitted through a half mirror 6, a condensing lens 9. Passing through the detection optical system of the one-dimensional solid-state image sensor 11,
It is displayed on the foreign object display section 17. Note that in this embodiment, the cylindrical lens 3 is used as the fused optical system 20. In addition, a semiconductor laser is used as the light source 1. Furthermore, a light-shielding optical system 10 is provided between the condensing lens 9 of the detection optical system and the one-dimensional solid-state imaging element 11, and its position corresponds to the Fourier transform surface of the condensing lens 9.

FIG. 4 shows the circuit pattern on sample 7. Also, wJs
The figure shows the shape of the light shielding plate in the light shielding optical system 10. Fifth
The light-shielding plate shown in Figure (α) is required only when using the epi-illumination detection system, and it blocks the specularly reflected light from the sample 7 when there is no circuit pattern on the sample 7 (only foreign matter is present). The purpose is to allow only the scattered light from to pass through.

The light-shielding plate shown in FIG. Sample 7 shown in the figure
It is used to block scattered light from circuit patterns such as 27 and 28 above. Therefore, these light shielding plates are
K can be arbitrarily selected depending on the illumination detection optical system used and the shape of the circuit pattern on the sample.

FIG. 10 shows a partial IS diagram of the epi-illumination detection system.

In the epi-illumination detection system, a case can be considered in which the bar 7 mirror 6 is located above the condenser lens 9 as shown in FIG. 10 (al).

However, in both cases where the sample 7 is irradiated from the X direction and detected in the B direction, and when the sample 7 is irradiated from the C direction and detected in the D direction, the reflected light 22 from the condenser lens 9 is accompanied by stray light. . Therefore, in order to eliminate stray light caused by illumination, in the apparatus of the present invention, the half mirror 6 is placed 9tlK below the condenser lens 9, as shown in FIG. 10+A+.

FIG. 14 shows an explanatory diagram of the dough scanning method. The width α in the longitudinal direction (X direction) of the light of early autumn 8 illuminated on sample 7 is
Corresponds to the inspection range in the direction. Therefore, in order to inspect the entire inspection area on the sample 7, it is only necessary to move the sample 7 in the Y direction. Therefore, the inspection time is significantly reduced compared to the conventional method.

FIG. 15 shows a flowchart of the procedure for using the device of the present invention. 5, the illumination detection system is selected depending on the presence or absence of a circuit pattern on the sample 7 and the flatness of the sample 7, and the light shielding plate is selected depending on the shape of the circuit pattern on the sample 7.

As described above, according to this embodiment, highly accurate foreign object detection is possible.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to perform stable strip-like illumination on the surface of the object to be inspected without providing any movable parts in the illumination system. This has the effect of significantly shortening the inspection time since the inspection can be carried out quickly, and by using a semiconductor laser as the light source, the entire inspection apparatus can be made smaller.

In addition, by installing an epi-illumination system between the imaging lens and the object to be inspected to illuminate the surface of the object to be inspected, M
The problem of stray light caused by reflection of illumination light on the lens surface of the image lens was solved. This has great effects, such as greatly improving the S/H of foreign object detection, stably detecting foreign objects, and shortening inspection time.

Further, according to the present invention, as follows: 1> Since the sample can be illuminated mechanically, the entire surface of the sample can be quantified for foreign matter in a short time.

2) 20,000 types of oblique illumination optical system and epi-illumination optical system can be selected arbitrarily depending on the characteristics of the sample (flatness, presence or absence of circuit pattern, etc.), high SN and high discrimination ratio (circuit pattern output The foreign object can be detected using the output value of the foreign object relative to the foreign object value.

S) Since a semiconductor laser is used as a light source, it has good light focusing ability and excellent pointing stability (irradiation position stability), making it possible to detect foreign objects with high f[ff]. Therefore, the foreign matter inspection device can be made more compact.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an apparatus showing an embodiment of the present invention, and FIG. 2 is an arrangement of the illumination system. Figure 3 is an explanatory diagram of the arrangement of the detection system, Figure 4 is a diagram of the circuit pattern on the sample, Figure 5 is the shape of the reduction plate-1, Figure 6 is a diagram showing an example of the light shielding plate replacement method,
Fig. 7 is a diagram showing the feeding direction of the sample, Fig. 8 is an explanatory diagram of the simultaneous calibration method for both sides of the sample, Fig. 9 is a perspective view of the apparatus showing another example of the present invention, and Fig. 10 is A partial configuration diagram of the epi-illumination/detection system, Fig. 11 is a tf-a explanatory diagram of the illumination system, Fig. 12
Figure 13 is a perspective view of an apparatus showing another embodiment of the present invention.
The figure shows the relationship between the spot position of the illumination light and the sample. f
FIG. 14 is an explanatory diagram of the edge constant strain method, FIG. 15 is a flowchart of the method of use of the present invention, and FIG. 16 is a perspective view showing the structure of a conventional detection optical system. Figure 17 is an optical path diagram showing reflected light from a sample in a conventional detection optical system.
FIG. 8 is an optical path diagram showing scattered light from a foreign object in a conventional detection optical system. 1... Light source 2... Condensing lens 5...
・Cylindrical lens 4...Illumination lens 5...Oblique illumination system 6...))-7 Mirror 7...Sample
8... Thin spot 9... Imaging lens 10... Reduction plate 11... Detector
15...2 m conversion circuit 16... arithmetic circuit
17...Foreign object display section 2nd port 1 Figure q (α) - Figure (b) Figure (C) Ra figure) O Figure (α) <b) , a, +2 times Figure 5) 3 (α) Wa (b) Kaisong Dynasty painting

Claims (1)

[Claims] 1. A light source, a linear condensing optical system that linearly illuminates a sample,
an imaging lens for forming an image of the light reflected from the linear illumination area from the sample; a light shielding means for blocking at least the regularly reflected light from the sample for the linear illumination area; and reflected light that has passed through the light shielding means. What is claimed is: 1. A foreign matter detection device comprising: an image sensor for detecting foreign matter attached to a sample surface; 2. Claim characterized in that a half mirror is provided between the sample and the imaging lens to reflect the illumination light from the linear condensing optical element and to pass the reflected light from the sample. 1. The foreign substance inspection device according to 1. 3. The light blocking means can form different light blocking patterns;
2. The foreign object detection device according to claim 1, further comprising switching means. 4. Emit light from a light source, perform linear illumination on the sample using a linear focusing optical system, form an image of the reflected light from the linear illumination area from the sample using an imaging lens, and use a light shielding means to illuminate at least the sample. A method for detecting foreign matter, characterized in that specularly reflected light from the linear illumination area is blocked, and the reflected light that has passed through the light blocking means is detected by an image sensor to detect foreign matter adhering to a sample surface. 5. A half mirror provided between the sample and the imaging lens reflects the illumination light from the linear condensing optical element and allows the reflected light from the sample to pass through. 4. Foreign substance inspection method described in 4. 6. Emit light from a light source, perform linear illumination on a sample having a pattern using a linear condensing optical system, form an image of the reflected light of the linear illumination area from the sample using an imaging lens, and use a light shielding means to The specularly reflected light from the sample surface in the linear illumination area and the reflected light from the pattern on the sample surface are blocked, and the reflected light that has passed through the light blocking means is detected by an image sensor and is attached to the sample surface having the pattern. A foreign object detection method characterized by detecting a foreign object. 7. An epi-illumination optical system having a light source and a linear optical system; an oblique illumination optical system having a light source and a linear optical system; It is characterized by being equipped with a detection optical system having a condensing lens that forms an image on the element and a light-shielding optical system, and a calculation means that calculates a signal obtained from the one-dimensional solid-state image sensor to detect a foreign object. Foreign matter inspection equipment. 8. The foreign matter inspection apparatus according to claim 7, wherein the light from the epi-illumination optical system is configured to enter an optical path between the condenser lens and the sample and illuminate the sample. 9. The light shielding optical system of the detection optical system is a light shielding system that blocks specularly reflected light from the sample surface generated by the epi-illumination optical system, or blocks scattered light from various patterns on the sample depending on the pattern. 8. The foreign matter inspection device according to claim 7, further comprising a plate that can be changed arbitrarily. 10. The foreign matter inspection apparatus according to claim 7, wherein a semiconductor laser is used as a light source for the epi-illumination optical system and the oblique illumination optical system.