JP2001124538A - Method and device for detecting defect in surface of object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect every defect, such as a slip, which occurs in the surface of an object such as a semiconductor wafer using a simple constitution with high accuracy. SOLUTION: A prescribed image 7 is formed in an image space 15 in such a way that a difference in an image-forming state occurs between a surface part 5 without defects and a defective part 6 with a defect in an object surface 4 at capturing of object surface 4 from the direction of regular reflection A. Then by capturing the prescribed image 7 formed in the image space 15 from the direction of regular reflection A, the surface part 5 is distinguished from the defective part 6 according to the difference of an image-forming state. More specifically, it is determined that there is no slippage 6 in a part 5 at which the image of slits 3 is formed satisfyactorily and that there is the slippage 6 in a part 6, at which the image of the slits 3 are not formed (or a part at which the image-forming state of an image-formed object is not satisfactory).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for inspecting a surface of an object for defects. More particularly, the present invention relates to a method and an apparatus suitable for inspecting a stepped defect such as a slip generated on a mirror-finished surface such as a semiconductor wafer.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor wafer, a linear scratch called a slip line (hereinafter referred to as "slip") occurs on the wafer surface. This slip is a defect with a step relative to the wafer surface. Steps with respect to the surface are several tens nm to several hundreds
on the order of nm.

[0003] Slip inspection of a wafer surface is performed visually by a specialized inspector.

However, there are the following problems.

[0005] 1) Training of specialized inspectors is required, and it takes a long time.

[0006] 2) Individual differences occur in the test results due to differences in the skill levels of the specialized inspectors.

[0007] 3) It is difficult to quantify test results on an objective scale.

4) Since the quantification of inspection results is insufficient, the accumulation of past inspection results cannot be sufficiently reflected in process improvement.

Therefore, attempts have been made to automate the slip inspection of the wafer surface without relying on humans.

Japanese Patent Application Laid-Open No. 4-42945 discloses an invention in which the position and length of a slip are automatically inspected by irradiating light on a wafer surface and detecting light reflected in a scattering direction. .

The present invention utilizes the phenomenon that if there is a slip on the wafer surface, scattered light is surely generated in a specific direction determined by the crystal plane orientation (the direction of the crystal axis).

However, the intensity of the scattered light is very small. For this reason, it is necessary to use a highly sensitive optical sensor, camera, or the like to detect scattered light. Therefore, there is a problem that the cost of the inspection apparatus increases. Further, since the scattered light generated by the slip is detected, it is not possible to inspect for defects other than the slip (scratch scratches on the object surface, foreign substances such as dust, etc.). In addition, it is necessary to obtain information on the crystal plane orientation of the wafer beforehand and to input the information as data. Therefore, there is a problem that the work involved in the inspection is troublesome.

Therefore, it is desired that it is possible to accurately inspect not only slips but also defects other than slips without the need for inputting data in advance and using high-sensitivity optical sensors and cameras.

Japanese Patent Application Laid-Open No. Hei 10-19971 discloses that
The intensity distribution of the luminescence light generated by the semiconductor by irradiating the wafer surface with the light and once absorbing the light by the semiconductor
An invention is described in which an image is taken by a D camera, and an image processing is performed on the taken image to check for a defect such as a slip on a wafer surface.

However, the process of determining the presence or absence of a defect such as a slip by performing image processing on the distribution of the intensity of the luminescent light becomes very complicated.

Therefore, it is desired that a simple inspection can be performed without complicated image processing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and solves the problem that any defect such as slip generated on the surface of an object such as a semiconductor wafer can be inspected with a simple structure and with high accuracy. It is an issue.

[0018]

Means and Effects for Solving the Problems The first aspect of the present invention.
The present invention provides, on an object surface,
In a defect inspection method for an object surface, which inspects a defect on the object surface by reflecting light and capturing light reflected on the object surface, there is no defect on the object surface when the light is captured from a regular reflection direction. A predetermined image is formed in an image space so that a difference in imaging state occurs between a surface portion and a defective portion having a defect, and the predetermined image formed in the image space is formed.
It is characterized in that the surface portion and the defective portion are distinguished according to the difference in the imaging state by capturing from the regular reflection direction.

The first invention will be described with reference to FIGS. 3, 4B and 10. FIG.

According to the first aspect, when the object surface 4 is captured in the regular reflection direction A, a difference in imaging state occurs between the defect-free surface portion 5 and the defect-free surface portion 6 of the object surface 4. A predetermined image 7 is formed in the image space 15.

The predetermined image 7 formed in the image space 15
Are detected from the specular reflection direction A, so that the surface portion 5 and the defective portion 6 are determined according to the imaging state difference.
Specifically, a portion 5 where the image of the slit 3 is well formed
It is determined that the slip 6 does not exist, and the slip 6 is determined to be present in a portion 6 where the image of the slit 3 is not formed (or a portion where the image is formed but the image formation state is not good).

As described above, according to the first aspect, the presence or absence of the defect 6 can be inspected accurately with a simple configuration in which the predetermined image 7 is formed in the image space 15 and captured from the regular reflection direction A. it can. In addition, light only needs to be captured in the regular reflection direction A, and it is not necessary to capture scattered light generated by slipping from a specific direction as in the related art, so that it is not necessary to input crystal plane orientation data in advance. Defects other than slip can also be inspected.

According to a second aspect of the present invention, in the first aspect, the predetermined image is an image having a predetermined pattern whose focus can be adjusted according to an image forming state.

According to the second aspect, when the image 7 of the predetermined pattern 3 (slit 3) is formed in the image space 15, the formation state of the image 7 of the pattern 3, that is, the edge portion becomes clear. Can be easily focused.

According to a third aspect of the present invention, there is provided a defect inspection apparatus for inspecting a defect on the surface of an object by reflecting light on the surface of the object and capturing the light reflected on the surface of the object. Image forming means for forming a predetermined image in an image space so that a difference in imaging state occurs between a surface portion having no defect on the object surface and a defective portion having a defect when captured from the reflection direction; and Imaging means for imaging the predetermined image formed in the image in the regular reflection direction, and discriminating between the surface portion and the defective portion according to an image formation state difference of the predetermined image imaged by the imaging means. It is characterized by doing.

The third invention will be described with reference to FIGS. 1 and 2 (b).

According to the third aspect, when the reflected light L2 reflected on the object surface 4 is detected in the regular reflection direction A, the surface portion 5 having no defect on the object surface 4 and the defect portion 6 having the defect are connected. The predetermined image 7 is placed in the image space 15 so that a difference in image state occurs.
Formed.

The predetermined image 7 formed in the image space 15
Is imaged by the imaging means 9 in the regular reflection direction A.

The predetermined image 7 picked up by the image pickup means 9
The defect-free surface portion 5 and the defect portion 6 are determined according to the difference in the imaging state.

As described above, according to the third aspect, similarly to the first aspect, the predetermined image 7 is formed in the image space 15 and is picked up in the regular reflection direction A. Can be inspected. In addition, light may be imaged in the regular reflection direction A, and it is not necessary to detect scattered light generated by slipping from a specific direction as in the related art, so that there is no need to input crystal plane orientation data in advance. Defects other than slip can also be inspected.

Further, it is sufficient that the image 7 of the regular reflection light L2 having a large light intensity in the regular reflection direction A can be captured. For this reason, the sensitivity of the imaging unit 9 may be lower than in the case of imaging scattered light with low light intensity. For this reason, the cost of the inspection device can be reduced.

According to a fourth aspect of the present invention, in the third aspect, the projecting means includes a light irradiating means for irradiating the object surface with light, and the predetermined means interposed between the light irradiating means and the object surface. And a light transmitting means for transmitting light of a pattern corresponding to the image of (1).

According to the fourth aspect, the light is irradiated by the light irradiation means 1 toward the object surface 4. Then, the light of the predetermined pattern 3 (slit 3) is transmitted by the light transmitting means 2, and the predetermined image 7 is formed in the image space 15.

According to a fifth aspect of the present invention, in the third or fourth aspect, the predetermined image is an image having a predetermined pattern whose focus can be adjusted according to an image forming state.

According to the fifth aspect, when the image 7 of the predetermined pattern 3 (slit 3) is formed in the image space 15, the formation state of the image 7 of the pattern 3, that is, the edge portion becomes clear. Can be easily focused.

[0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an object surface inspection method and apparatus according to the present invention; In this embodiment, the surface of the semiconductor wafer is assumed as the object surface. The defect is assumed to be a slip generated on the surface of the semiconductor wafer. However, the present invention is applicable to inspection of any defect other than slip. For example, the present invention can be applied to inspection of foreign substances such as scratches and dust generated on the wafer surface.
The present invention is not limited to semiconductor wafers and is applicable to inspection of defects generated on any mirror-finished object surface.

FIG. 1 is a diagram showing a configuration of a semiconductor wafer inspection apparatus according to the embodiment.

This apparatus is for inspecting the presence or absence, the position, and the length of the slip 6 generated on the surface 4 of the semiconductor wafer.

As shown in FIG. 1, the light source 1 emits incident light L 1 toward the wafer surface 4. As the light source 1, for example, a fluorescent lamp can be used.

Between the light source 1 and the wafer surface 4, there is provided a sheet 2 on which a slit 3 is printed and which transmits the light L1.

As the sheet 2, a transparent OHP (overhead projector) sheet can be used. The slit 3 is formed by arranging black lines 3a in parallel at regular intervals. The width of the black line 3a and the width of the underlying transparent line are set to, for example, 1: 1. The width of the black line 3a is set to, for example, 0.5 mm. Note that 1 mm, 2,
It may be 0 mm or 3.0 mm.

The pattern to be printed on the surface of the sheet 2 is not limited to a pattern in which the black lines 3a such as the slits 3 are arranged in parallel at regular intervals. For example, as shown in FIG. 6A, the pattern to be printed on the sheet 2 may be a pattern in which black circles are arranged concentrically. As shown in FIG. 6B, the pattern to be printed on the sheet 2 may be a pattern in which black lines are radially arranged.

In short, as a pattern to be printed on the sheet 2, when the image 7 of the pattern is formed in the image space 15 as shown in FIG.
In this case, any pattern can be used as long as it can be focused by confirming that the outline of the slit 3 is clear. Then, when the image 7 is captured in the regular reflection direction A, a pattern having a regular rule can be used so that the difference in the imaging state between the portion 5 having no slip 6 and the portion 6 having the slip 6 on the wafer surface 4 is clear.

Furthermore, if the pattern can be focused by any means, it is not required that the pattern to be printed on the sheet 2 be regular. For example, as shown in FIG. 6C, a square which is painted black on one surface may be printed on the sheet 2. Also in this case, when the image 7 is captured in the regular reflection direction A, the wafer surface 4
It is possible to cause a difference in the imaging state between the portion 5 having no slip 6 and the portion 6 having the slip 6.

The light source 1 and the sheet 2 described above constitute an image forming means.

FIG. 10 is a view showing a state in which the image 7 of the sheet 2 is formed in the configuration of FIG.

When the sheet 2 is irradiated with the incident light L 1 from the light source 1, the light is reflected using the wafer surface 4 as a reflecting mirror. Here, according to the law of reflection, the reflected light L2 has a direction A such that the reflected light L2 leaves a place 7 symmetrical with respect to the wafer surface 4 of the sheet 2. Therefore, by capturing the reflected light L2 reflected in the regular reflection direction A, an image is taken (visible) so that the sheet 2 as the virtual image 7 exists at the symmetrical point of the actual sheet 2. That is, assuming that the space where the actual sheet 2 exists in FIG. 10 is a real space 14, an image space 15 as an imaginary space is formed in a space symmetrical with respect to the wafer surface 4. In the image space 15, the image 7 of the sheet 2 having the same size and the symmetrical shape as the actual sheet 2 in the real space 14 is formed.

In the direction A for regular reflection of light, a CCD camera 9 for picking up an image 7 is provided. That is, the CCD camera 9 only needs to detect the regular reflection light L2 having a large light intensity. For this reason, the sensitivity may be lower than in the conventional case of detecting scattered light with low light intensity. For this reason, the cost of the entire inspection apparatus can be reduced. As the CCD camera 9, a microscope of model HV-7000 manufactured by Keyence Corporation can be used. This microscope has 1.5 million pixels and a magnification of 5 times.

The image pickup signal of the CCD camera 9 is transmitted to the display device 10.
Is input to The image 7 in the image space 15 is displayed on the display screen 10a of the display device 10.

The display contents are shown in FIGS. 2 (a) and 2 (b). FIG. 2A is a display result when the slip 6 does not exist on the wafer surface 4. FIG. 2B is a display result when the slip 6 exists on the wafer surface 4.

Next, the operation of the inspection apparatus will be described.

First, as an operator, the focal length of the light source 1 is adjusted. More specifically, a process of capturing an image 7 and focusing on the basis of the state of formation of the slit 3 on the surface of the sheet 2 is performed. The image 7 showing the slit 3 is the display device 1
0 is displayed on the display screen 10a. It is determined that focus has been achieved when the edge portion of the slit 3 becomes clear with respect to the background on the display screen 10a. The processing for adjusting the focal length may be performed automatically or manually.

FIG. 7 shows a state where the focal point 11 is set to the slit 3 on the surface of the sheet 2. At this time, the edge portion of the image 7 of the slit 3 is clearest.
In FIG. 7, 12 indicated by a solid line is a real image, and 13 indicated by a broken line is a virtual image.

Next, by changing the relative position between the wafer surface 4 and the light source 1, the inspection for the presence or absence of the slip 6 at each part of the wafer surface 4 is sequentially performed. Specifically, an image 7 corresponding to each part of the wafer surface 4 is sequentially displayed on the display screen 10a of the display device 10 by mounting the wafer on the stage and sequentially moving the stage.

FIG. 2A shows a state where there is no slip 6. On the display screen 10a, an image 7 showing the regularly arranged slits 3 is displayed. That is, slit 3
Is generally good. From the display contents in which the image forming state of the slit 3 is generally good and the slits 3 are regularly arranged in this manner, the operator
It can be determined that there is no slip 6.

FIG. 2B shows a state where the slip 6 exists. At this time, as shown in FIG. 2B, on the display screen 10a, there is a difference in the imaging state between the portion where the slip 6 occurs and the portion 5 where the slip 6 does not exist. This is for the following reason.

1) Since the slit 3 on the surface of the sheet 2 is focused on the premise that the wafer surface 4 is in a mirror state, the portion of the slip 6 having a step with respect to the wafer surface 4 is not a mirror surface. The light rays reflected by the slip 6 are out of focus. Therefore, the slit 3 is clearly displayed in the non-slip portion 5 where no slip 6 is present, and the slit 3 is displayed blurred in the portion where the slip 6 exists.

2) The CCD camera 9 detects light L2 that is specularly reflected from the mirror-finished wafer surface 4. On the other hand, since the light is scattered by the slip 6 having a step which is not a mirror surface, the light L2 reflected specularly cannot be detected. For this reason, the light intensity increases in the non-slip portion 5 where no slip 6 exists, and the light intensity decreases in the portion where the slip 6 exists.

As a result, as shown in FIG. 8A, the portions R1, R2 corresponding to the light beams S1, S2 reflected on the wafer surface 4
Thus, the image 7 of the slit 3 is favorably formed. However, the image 7 of the slit 3 is not formed in the portion R3 corresponding to the light beam S3 reflected by the step 6 (slip).

For the above reasons, as shown in FIG.
Part where slip 6 occurs and part 5 where no slip 6 occurs
And a difference in the imaging state occurs, and the slit 3 is missing (appears white) and displayed at a portion where the slip 6 exists. In addition, since the slits 3 are arranged in a regular pattern, the regularity is distorted and displayed in a portion where the slip 6 occurs. Therefore, the operator can clearly recognize the slip 6 when the regularity of the pattern is broken due to the difference in the imaging state difference.

As described above, the operator determines that there is no slip 6 in the portion 5 where the image of the slit 3 is well formed, and the slip 6 exists in the missing portion 6 where the image of the slit 3 is not formed. Can be determined.

It should be noted that, instead of the slit 3, FIG.
The same effect can be obtained by using the regular pattern shown in FIG. 6C instead of the slit 3
Even if you use the square that is painted black on one side shown in
Part where slip 6 occurs and part 5 where no slip 6 occurs
And a difference in the imaging state occurs, and the slip 6 is displayed in white as a missing portion of the slit 3, so that the slip 6 can be clearly recognized.

As described above, the position on the wafer where the slip 6 has occurred and the length of the slip 6 can be recognized by visually observing the display screen 10a of the display device 10. The position of the slip 6 can be measured based on the movement position of the stage. Further, the length of the slip 6 can be recognized from the size relative to the slit 3. More specifically, the number of black lines 3a corresponding to the white protruding portion (slip 6) is determined, and the angle at which the white protruding portion (slip 6) intersects the black line 3a is determined. Number and black line 3
The length of the slip 6 can be calculated based on the width of a and the angle intersecting the black line 3a.

The position and length of the slip 6 may be automatically measured by performing image processing based on the image pickup result of the CCD camera 9.

FIG. 5A shows an image actually picked up by the CCD camera 9. It was confirmed that the slip 6 clearly appeared white on the slit 3.

FIG. 5B shows an image after edge processing for enhancing the brightness difference is performed on the image of FIG. 5A. The slip 6 could be more clearly recognized as the degree of edge processing was increased.

FIG. 5 (c) shows an image after the relief processing for inverting the brightness is performed on the image of FIG. 5 (a). On the image after the relief processing, it was difficult to confirm the existence of the slip 6. The greater the degree of the relief processing, the more difficult it was to confirm the presence of the slip 6.

In the above embodiment, the image of the CCD camera 9 is displayed and the slip 6 is inspected.
However, the inspection of the slip 6 may be performed by viewing the image 7.

FIG. 3 shows an apparatus for performing a visual inspection without providing a CCD camera 9 and a display device 10 as compared with the configuration of FIG. Instead of the CCD camera 9, light L2 reflected in the regular reflection direction A is captured visually.

FIG. 4A shows a state where there is no slip 6. By visually checking that the imaging state of the slits 3 is generally good and the slits 3 are regularly arranged, the operator can determine that there is no slip 6.

FIG. 4B shows a state where the slip 6 exists.

At this time, as seen from the human eye as shown in FIG. 4B, in the same manner as when the image was taken by the CCD camera 9 in FIG. There is a difference in the image formation state between the portion 5 having no mark and the portion 5 having no mark. That is, as shown in FIG. 8 (a), in the portions R1 and R2 corresponding to the light beams S1 and S2 reflected on the wafer surface 4, the image 7 of the slit 3 is formed.
Are imaged well. However, the image of the slit 3 is not well formed in the portion R3 corresponding to the light beam S3 reflected by the step 6 (slip).

For the above reasons, as shown in FIG. 4 (b), when viewed with human eyes, a difference in imaging state occurs between the portion where the slip 6 occurs and the portion 5 where the slip 6 does not exist. In a certain portion, the pattern of the slit 3 is displayed with a shift. In addition, since the slits 3 are arranged in a regular pattern, the regularity is distorted and displayed in a portion where the slip 6 occurs. Therefore, the operator can clearly recognize the slip 6 when the regularity of the pattern is broken due to the difference in the imaging state difference.

By the way, comparing FIG. 2B and FIG. 4B, in the image picked up by the CCD camera 9, the slip 6 is observed as a white portion as a missing portion of the slit 3, whereas the slip 6 is visually observed. There is a difference that the slip 6 is observed as a shift of the slit 3. This is considered to be because the resolution, the depth of focus, and the like of the CCD camera 9 are inferior to those of human eyes. However, the resolution of the CCD camera 9
If the depth of focus or the like is set equal to that of the human eye, the image shown in FIG. 4B equivalent to that seen by the human eye can be captured. In addition, by increasing the magnification of the CCD camera 9, it becomes possible to perform measurement beyond human eyes.

As described above, according to the present embodiment, the image 7 of the surface of the sheet 2 is formed in the image space 15 and the image 7 is visually observed in the specular reflection direction A or imaged by the imaging means such as the CCD camera 9. With such a simple configuration, the presence / absence, position, length and the like of a defect such as the slip 6 can be inspected with high accuracy. Further, it is only necessary to catch light in the regular reflection direction A, and it is not necessary to catch the scattered light generated by the slip 6 in a specific direction as in the prior art. Therefore, it is necessary to input crystal plane orientation (specific direction) data in advance. There is no.

Further, defects other than the slip 6 can be inspected. For example, FIG. 8B shows a state in which a convex foreign matter 6 ′ generated on the wafer surface 4 is inspected. As shown in FIG. 8A, the light beam S reflected on the wafer surface 4
In the portions R1 and R2 corresponding to 1 and S2, the image 7 of the slit 3 is favorably formed. However, the ray S3 reflected by the foreign matter 6 '
In the portion R3 corresponding to the above, the image of the slit 3 is not formed or is not formed well. As a result, as shown in FIG. 2B, the slit 3 is missing (displayed in white) at a portion where the foreign matter 6 'is present. Alternatively, as shown in FIG. 4 (b), the pattern of the slit 3 is displayed with a shift in a portion where the foreign matter 6 'exists.

Further, when an image pickup means such as a CCD camera 9 is used, it is sufficient that the image 7 can be picked up in the regular reflection direction A where the light intensity is high. For this reason, the sensitivity of the imaging means may be lower than in the case of imaging scattered light with low light intensity. For this reason, the cost of the inspection device can be reduced.

In this embodiment, as shown in FIG. 9A, light from the light source 1 is irradiated from the back of the transparent sheet 2 and the light transmitted through the transparent sheet 2 is reflected on the wafer surface 4 and is specularly reflected. By capturing in the direction A, the image 7 can be captured or directly viewed. However, the present invention may have any configuration as long as the image 7 can be formed in the image space 15 and the image 7 can be captured in the regular reflection direction A. For example, FIG.
As shown in FIG. 7, an opaque plate 2 'is used in place of the transparent sheet 2 and the surface of the opaque plate 2' is illuminated by the light of the light source 1 provided at an arbitrary position to form an image 7 on the surface of the opaque plate 2 '. You may make it catch in the regular reflection direction A.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a slip inspection device according to an embodiment;

FIGS. 2A and 2B are diagrams showing contents displayed on the display device shown in FIG. 1. FIG.

FIG. 3 is a diagram showing another configuration example of the slip inspection device of the embodiment.

FIGS. 4 (a) and 4 (b) are diagrams showing contents visually captured. FIG.

5 (a), 5 (b) and 5 (c) show CCs shown in FIG.
It is a figure which shows the picked-up image of the D camera, and the processed image after performing predetermined processing to the picked-up image.

FIGS. 6A, 6B, and 6C are diagrams exemplifying an image pattern according to the embodiment;

FIG. 7 is a diagram showing a state in focus.

FIGS. 8A and 8B are diagrams for explaining an imaging state difference between a portion having no defect on a wafer surface and a portion having a defect. FIG.

FIGS. 9A and 9B are diagrams illustrating a configuration example of a defect inspection apparatus.

FIG. 10 is a diagram illustrating an image formed in an image space.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 2 Sheet 3 Slit 4 Wafer surface 5 Non-slip part 6 Slip 7 Image 9 CCD camera 10 Display device 15 Image space

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA49 BB03 BB13 BB25 CC19 DD00 DD10 FF04 FF10 FF44 GG03 HH02 HH06 JJ03 JJ12 JJ26 LL25 LL28 QQ31 SS13 2G051 AA51 AB07 BB07 CA03 CA04 CB01 BA04CA10 DB30 5B057 DA03 DB05 DC16 DC22

Claims (5)

[Claims] An object surface defect inspection method for inspecting a defect on an object surface by reflecting light on the object surface and capturing light reflected on the object surface, wherein the light is captured from a regular reflection direction. Forming a predetermined image in an image space such that a difference in imaging state occurs between a surface portion having no defect on the object surface and a defective portion having a defect when the predetermined image is formed in the image space. Detecting the surface portion from the specular reflection direction to determine the surface portion and the defect portion according to the imaging state difference. 2. The method according to claim 1, wherein the predetermined image is an image of a predetermined pattern whose focus can be adjusted in accordance with an image formation state. 3. An object surface defect inspection apparatus for inspecting a defect on an object surface by reflecting light on the object surface and capturing light reflected on the object surface, wherein the light is captured from a regular reflection direction. Image forming means for forming a predetermined image in an image space so that a difference in imaging state occurs between a surface portion having no defect on the object surface and a defective portion having a defect when the image surface is formed. Imaging means for imaging the predetermined image in a specular reflection direction, wherein the surface part and the defect part are distinguished according to an imaging state difference of the predetermined image imaged by the imaging means. Defect inspection device for object surface. 4. The image forming unit includes: a light irradiating unit that irradiates light toward the surface of the object; and a light having a pattern corresponding to the predetermined image interposed between the light irradiating unit and the surface of the object. 4. An apparatus for inspecting defects on an object surface according to claim 3, further comprising light transmitting means for transmitting light. 5. The apparatus according to claim 3, wherein the predetermined image is an image having a predetermined pattern whose focus can be adjusted according to an image forming state.