JP2002350359A - Defect inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defect inspection device capable of precise inspection of defects independent of pitch of repeated pattern on a substrate. SOLUTION: The device comprises a lighting unit (13) which lights the inspected area (11a) of the substrate (11), an imaging system (24, 25) which forms an image of the area, an imaging device (26) which acquires the image formed with the system, a supporting unit (12) for the substrate, and an adjusting system (17, 18) for adjusting the relative arrangement among the supporting unit, the imaging system and the imaging device. The adjusting system (17, 18) adjusts the relative arrangement so that the shape of the image (11b) formed on the image plane of the imaging device (26) is approximately similar to the shape of the inspected area (11a).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect inspection apparatus for inspecting a defect on a substrate surface in a process of manufacturing a semiconductor circuit element or a liquid crystal display element.

[0002]

2. Description of the Related Art As is well known, in a manufacturing process of a semiconductor circuit element or a liquid crystal display element, a resist is formed through an exposure step of printing a circuit pattern on a photoresist film on a substrate and a development step of a photosensitive photoresist film. Is formed, and thereafter, through a processing step such as etching or vapor deposition, a circuit is formed on the substrate.

In the manufacturing process, if there is a defect in a circuit pattern formed by a resist, processing is performed according to the defect, resulting in a defective product. Therefore, a defect inspection of a circuit pattern using a resist has been conventionally performed.
The defect location is, for example, a location where the cross-sectional shape of the circuit pattern has changed due to the defocus of the exposure device, a location where the thickness of the resist has changed, or a location where there is a foreign substance or a scratch.

At present, defect inspection in the actual manufacturing process is performed by visual observation. However, in the visual observation, a sufficient inspection result cannot be obtained because the inspection standard changes depending on the skill and physical condition of the inspector.

Therefore, in recent years, it has been studied to automate this defect inspection. All of the automatic inspection apparatuses that have already been proposed take in an image (diffraction image) based on diffracted light from a repetitive pattern formed on a substrate and specify a defect portion based on the brightness of the diffraction image.
FIG. 6A is a side view showing an example of a conventional device. The substrate 51 to be inspected is placed on an inspection stage 52 and is illuminated by parallel illumination light L11 from an illumination unit 53. Then, the substrate 51 illuminated by the illumination light L11
From above, the diffracted light L12 is generated with a diffraction efficiency according to whether the position of the repetitive pattern is a defect or normal.

When the light receiving portion 54 for receiving the diffracted light L12 is fixed, the inspection stage 52 is tilted around an axis 52a along the X direction, so that the diffracted light L12 from the substrate 51 is transmitted to the light receiving portion 54. I can guide you. The tilt angle of the inspection stage 52 is obtained in advance according to diffraction conditions. Using the wavelength λ and the incident angle θi of the illumination light L11, the diffraction angle θd and the diffraction order m of the diffracted light L12, the tilt angle θt of the inspection stage 52, and the pitch p of the repetitive pattern, the diffraction condition is given by the following equation (1). Can be represented by

Sin (θd−θt) −sin (θi + θt) = mλ / p (1) In equation (1), the incident angle θi, the diffraction angle θd, and the tilt angle θt
Is a normal (reference normal) when the substrate 51 is kept horizontal as shown in FIG. 6B. The sign of the incident angle θi is plus in the angle direction seen on the incident side and minus in the angle direction seen on the reflection side. The range of the incident angle θi is
0 ° <θi <90 °.

The signs of the diffraction angle θd and the tilt angle θt are minus in the angle direction seen on the incident side and plus in the angle direction seen on the reflection side. Further, the diffraction order m is m
With reference to the 0th-order diffracted light (specular reflection light) of = 0, the angle direction seen on the incident side is defined as minus, and the angle direction seen on the reflection side is defined as plus. The diffracted light L12 guided to the light receiving unit 54 by the tilt of the inspection stage 52 according to the above-described diffraction condition (Equation (1)) is received by the image sensor 55,
A signal based on the image of the substrate 51 is output to the image processing unit 56. Since the diffraction efficiency is different between the defective portion and the normal portion of the substrate 51, light and darkness due to a pattern abnormality (defect) appears in the diffraction image. Therefore, in the image processing unit 56,
The location of the defect on the substrate 51 can be specified by the brightness of the diffraction image.

[0009]

However, in the above-described conventional apparatus, the different pitches p formed on the substrate 51 are different.
Inspection stage 52 for inspecting the repetition pattern of
Is tilted around the axis 52a, there is a problem that the image of the substrate 51 formed on the imaging surface of the imaging element 55 is deformed in one direction. The direction in which the image of the substrate 51 is deformed is a direction perpendicular to the axis 52a of the inspection stage 52.

The fact that the image of the substrate 51 on the imaging surface of the imaging element 55 is deformed means that the area of the image of the substrate 51 changes, and each of the two-dimensionally arranged images on the imaging surface of the imaging element 55. The size on the substrate 51 which is allocated to the pixel is also changed. For example, as the area of the image on the substrate 51 decreases, the size on the substrate 51 allocated to each pixel increases relatively. In this case, in the conventional device,
The resolution is reduced, and the accuracy of defect detection is also reduced.

In recent years, it has been proposed to provide a plurality of light receiving sections in order to simultaneously inspect repetitive patterns having different pitches p formed on the substrate 51. In this case, the plurality of light receiving units are fixed with their optical axes aligned with the traveling direction of the diffracted light generated from the corresponding repetitive pattern,
The inspection stage 52 is also fixed. Then, an image of the substrate 51 due to each diffracted light is formed on the imaging surface of the imaging device of each light receiving unit.

However, in an apparatus having a plurality of light receiving units,
There is a problem that the shapes of the images formed on the imaging surfaces of the respective light receiving units are different from each other. Further, that the shapes of the images on the imaging surface are different from each other means that the areas of the images are different, and the sizes on the substrate 51 allocated to the respective pixels on the imaging surface are also different. For this reason, in an apparatus including a plurality of light receiving units, in a light receiving unit in which the area of an image formed on the imaging surface is reduced, the resolution is reduced and the accuracy of defect detection is also reduced.

An object of the present invention is to provide a defect inspection apparatus capable of performing a highly accurate defect inspection irrespective of the pitch of a repetitive pattern formed on a substrate.

[0014]

The defect inspection apparatus of the present invention collects illumination means (13) for illuminating an inspection area (11a) of a substrate (11) and diffracted light (L2) from the inspection area. Glow,
An imaging optical system (24, 25) for forming an image of the inspection area;
An imaging device that captures an image formed by an imaging optical system
(26), support means (12) for supporting the substrate, and adjustment means (17, 18) for adjusting the relative positional relationship between the support means, the imaging optical system, and the image pickup device. In the adjusting means (17, 18), the shape of the image (11b) formed on the imaging surface of the imaging device (26) is substantially similar to the shape of the inspection area (11a). , The relative positional relationship is adjusted. Note that the numbers in parentheses in this paragraph indicate the symbols used in FIGS. 1 and 2, but the present invention is not limited to this.

Further, another defect inspection apparatus of the present invention provides a
Illumination means (13) for illuminating the inspection area (11a) of (11)
And an imaging optical system (34, 35) for condensing diffracted light (L3) from the inspection area to form an image of the inspection area, and an image sensor for imaging an image formed by the imaging optical system (36)
Support means (32) for supporting the substrate. The supporting means, the imaging optical system, and the imaging device tilt the substrate (11) with respect to the optical axis (O4) of the imaging optical system (34, 35), and perform imaging of the imaging device (36). Image formed on the surface
The shape of (11b) is fixedly arranged in a positional relationship that is substantially similar to the shape of the region to be inspected (11a). Note that the numbers in parentheses in this paragraph indicate the reference numerals used in FIGS. 2 and 4, but the present invention is not limited to this.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) A first embodiment of the present invention corresponds to claims 1 and 2. Defect inspection device 10 of the first embodiment
As shown in FIG. 1, an inspection stage 12 on which a wafer 11 on which a repetitive pattern is formed is mounted, an illumination unit 13 for illuminating the wafer 11 on the inspection stage 12, and a wafer 11 illuminated by the illumination unit 13 Light receiving unit 14 for receiving the diffracted light from the light source, an image processing device 15, and a display device 16
, A control device 17 and a memory 18.

The inspection stage 12 is provided with a tilt mechanism (not shown). This inspection stage 12
Can be tilted within a predetermined angle range around the tilt axis 12a. Here, the tilt axis 1 of the inspection stage 12
The direction parallel to 2a is defined as the X direction. A direction parallel to a normal line (reference normal line) in a state where the inspection stage 12 (wafer 11) is kept horizontal is defined as a Z direction. Further, a direction orthogonal to the X direction and the Z direction is defined as a Y direction.

The illumination section 13 is an eccentric optical system composed of a light source 21, a light guide 22, and a concave reflecting mirror 23. The light source 21 is composed of, for example, a metal halide lamp or a mercury lamp. The light guide 22 includes a light source 21
And is emitted from the end face 22a toward the concave reflecting mirror 23. The end face 22 a of the light guide 22 is arranged at a front focal position of the concave reflecting mirror 23.

The concave reflecting mirror 23 is a reflecting mirror having an inner surface of a spherical surface as a reflecting surface, and is disposed obliquely above the inspection stage 12. That is, an axis (optical axis O1) passing through the center of the concave reflecting mirror 23 and the center of the inspection stage 12 is inclined by a predetermined angle with respect to the Z direction. Also, the concave reflecting mirror 23
Indicates that the optical axis O1 is the tilt axis 12a (X
Direction). Therefore, a plane including the optical axis O1 and the normal line of the wafer 11 (incident plane)
Is parallel to the YZ plane.

Further, the concave reflecting mirror 23 is arranged so that the rear focal plane thereof substantially coincides with the wafer 11. For this reason, the illumination unit 13 of the defect inspection apparatus 10 has an optical system that is telecentric with respect to the wafer 11 side. In the illumination unit 13 configured as described above, light from the light source 21 is applied to the inspection area 11a (see FIG. 2A) of the wafer 11 via the light guide 22 and the concave reflecting mirror 23 (see FIG. 2A). Illumination light L1). As a result, diffracted light L2 is generated from the inspection area 11a of the wafer 11 according to the diffraction condition (see the above equation (1)). The intensity of the diffracted light L2 differs between a defective portion and a normal portion of the wafer 11.

Here, since the illuminating section 13 is telecentric on the wafer 11 side, the incident angle θi of the illuminating light L1 is
(Refer to the above equation (1)).
And the intensity of the diffracted light L2 generated from the inspection area 11a of the wafer 11
It becomes uniform for each state of 1a (defect / normal part and defect type).

On the other hand, the light receiving section 14 is an eccentric optical system composed of a concave reflecting mirror 24, an imaging lens 25, and an image sensor 26. The member supporting the light receiving unit 14 is not shown. The concave reflecting mirror 24 is the concave reflecting mirror 23 described above.
And a reflector which is arranged above the inspection stage 12. That is, the axis (optical axis O2) passing through the center of the concave reflecting mirror 24 and the center of the inspection stage 12 is arranged so as to be parallel to the Z direction. The optical axis O2 is included in the plane of incidence.

The concave reflecting mirror 24 is disposed so that its front focal plane substantially coincides with the wafer 11. For this reason, the light receiving section 14 of the defect inspection apparatus 10 is an optical system that is telecentric with respect to the wafer 11 side. Further, the imaging lens 25 is arranged such that the front focal position thereof substantially coincides with the rear focal position of the concave reflecting mirror 24. Note that the rear focal position of the concave reflecting mirror 24 is
4 and is conjugate to the end surface 22a of the light guide 22 of the illumination unit 13 described above.

The image pickup device 26 is a CCD image pickup device in which a plurality of pixels are two-dimensionally arranged, and is arranged with its image pickup surface substantially coincident with the rear focal plane of the imaging lens 25. For this reason, the light receiving unit 14 of the defect inspection apparatus 10 has an optical system that is telecentric with respect to the imaging element 26 side. That is, the light receiving unit 14 is a two-sided telecentric system. Note that the imaging surface of the imaging element 26 is
Is conjugate to the surface of

The image sensor 26 is provided with a tilt mechanism (not shown). The image sensor 26 can be tilted within a predetermined angle range around the tilt axis 26a. The tilt axis 26a of the imaging element 26 is
Axis (optical axis O3) passing through the center of the lens and the center of the imaging lens 25
And the tilt axis 12 of the inspection stage 12
a (X direction) is parallel.

In the light receiving section 14 configured as described above, the diffracted light L2 generated from the inspection area 11a of the wafer 11 is condensed via the concave reflecting mirror 24 and the imaging lens 25, and Reach the imaging surface. Image sensor 2
An image of the wafer 11 is formed on the imaging surface 6 by the diffracted light L2. Note that, since the wafer 11 side of the light receiving unit 14 is a telecentric system, the diffraction angle θd of the diffracted light L2 (see the above equation (1)) becomes uniform over the entire inspection area 11a of the wafer 11, and The intensity of the diffracted light L2 that reaches the imaging surface (the intensity of the image on the wafer 11) is also uniform for each state (defect / normal portion or defect type) of the inspection target area 11a.

Therefore, the strength of the image pickup signal (the signal based on the image of the wafer 11 by the diffracted light L2) output from the image pickup element 26 includes the state of the inspected area 11a of the wafer 11 (defects / normal portions and types of defects). ) Will be reflected.

The image processing device 15 connected to the image sensor 26 captures an image signal output from the image sensor 26 and performs pattern matching by comparing the image of the wafer 11 with the image of a good wafer stored in advance. Alternatively, image processing is performed to determine whether or not an image of the wafer 11 includes a portion different from the characteristics of the non-defective wafer 11. For example, when there is a defect such as unevenness due to defocus, a defective portion of the wafer 11 is recognized based on information such as a difference in brightness or a difference in characteristics of the portion.

Further, the display device 16 connected to the image pickup device 26 and the image processing device 15 displays an image of the wafer 11 based on the image pickup signal from the image pickup device 26, and outputs an image from the image processing device 15. For example, information on a defective portion of the wafer 11 is displayed based on the information. The display device 16 has a CR
Examples include a T monitor and a liquid crystal display monitor. In addition,
As described above, the illumination unit 13 and the light receiving unit 14 are an optical system that is telecentric with respect to the wafer 11 side. The same can be made over the entire surface of the inspection area 11a. That is, the inspection area 1
Even if the XY position in 1a is different, the appearance is the same if the same defect exists.

The image pickup device 26 and the inspection stage 1
The control device 17 connected to the camera 2 rotates the inspection stage 12 around the tilt axis 12 a based on the contents stored in the memory 18, and interlocks the imaging device 26 with the tilt axis 26 a in conjunction with the rotation of the inspection stage 12. Control to rotate around. The memory 18 includes a plurality of types of wafers 11.
Various setting conditions (recipes) for optimally performing defect inspections on wafers (for example, wafers having different repetition pattern pitches p) are stored in advance.

Next, the operation of the defect inspection apparatus 10 configured as described above will be described with reference to the flowchart of FIG. When the wafer 11 to be inspected is placed on the inspection stage 12 and information on the type of the wafer 11 is input from outside (for example, an input device (not shown)), the control device 17 performs control based on the flowchart of FIG. Start.

The controller 17 first reads a recipe corresponding to the type of the wafer 11 to be inspected from the memory 18 (step S1), and tilts the inspection stage 12 based on the content of the read recipe (step S2). Then, the image sensor 26 is also tilted in conjunction with the tilt of the inspection stage 12 (step S3). At this time, the tilt of the image sensor 26 is performed by the same angle as the tilt of the inspection stage 12. As a result, as shown in FIG. 2B, the inclination angle α of the imaging surface of the image sensor 26 with respect to the optical axis O3 of the light receiving
(Α = β). In FIG. 2B, for the sake of simplicity, the concave reflecting mirror 24 is replaced with a convex lens.

In the defect inspection apparatus 10 of the first embodiment, since the light receiving section 14 is a telecentric system on both sides, the inclination angle α of the imaging surface of the imaging element 26 is adjusted to be equal to the inclination angle β of the wafer 11 so that the imaging element The 26 side and the wafer 11 side have a geometrically similar relationship. At this time, the image sensor 2
The shape of the image 11b (the image of the inspection area 11a of the wafer 11) formed on the imaging surface 6 is, as shown in FIG. 2C, the shape of the inspection area 11a (see FIG. 2A). On the other hand, it is almost similar.

That is, the inspection area 11a of the wafer 11
Let D _{A1 be} the diameter in the direction of the tilt axis 12a, and D _B1 be the diameter in the direction perpendicular to the tilt axis 12a.
If the diameter in the direction of the tilt axis 26a is D _A2 and the diameter in the direction perpendicular to the tilt axis 26a is D _B2 , D _A1 : D _B1 = D _A2 : D
_B2 holds. For example, the inspection area 11a of the wafer 11
Is circular, the image 11b formed on the imaging surface is also circular.

The diameter D of the image 11b formed on the image pickup surface
_A2, D _B2, compared diameter D _A1, D _B1 of the inspection area 11a, which in turn are multiplied by the magnification of the optical system determined by the concave reflecting mirror 24 and the imaging lens 25.

If the inclination angle α of the imaging surface of the imaging device 26 is adjusted to an angle different from the inclination angle β of the wafer 11 (α ≠ β), the shape of the image 11b formed on the imaging surface is as shown in FIG. As shown in (d), the shape does not become similar to the shape of the inspection area 11a (see FIG. 2A) (D _A1 :
D _B1 ≠ D _A2 : D _B3 ). For example, when the inspection area 11a is circular, the image 11b formed on the imaging surface is
Is compressed in the direction perpendicular to the tilt axis 26a (oval).

In the defect inspection apparatus 10 according to the first embodiment, the inclination angle α of the imaging surface of the imaging element 26 is
The process proceeds to step S4 in FIG. 3 in a state where the shape of the image 11b formed on the imaging surface is substantially similar to the shape of the inspection area 11a. Control device 17
Controls the image pickup device 26 to output an image pickup signal based on the image 11b (see FIG. 2C) formed on the image pickup surface to the image processing device 15 and the display device 16 in step S4.

Thereafter, the image processing device 15 performs image processing such as the above-described pattern matching on the image pickup signal fetched from the image pickup element 26, and recognizes a defective portion in the inspection area 11a of the wafer 11. In addition, the display device 16 displays an image of the inspection target area 11 a based on an image pickup signal from the image pickup device 26, and displays information on a defective portion based on an output signal from the image processing device 15.

As described above, the defect inspection apparatus of the first embodiment
According to 10, the type of the wafer 11 (repeated pattern
When the inspection stage 12 is tilted according to the pitch p),
The image sensor 26 is tilted by the same angle
The inclination angle α of the imaging surface of the element 26 is defined as the inclination angle β of the wafer 11.
In order to adjust equally, the type of wafer 11 (repeated pattern
Shape of the imaging surface, even if the
The shape of the formed image 11b is substantially
A similar shape (D_A1: D_B1= D _A2:
D_B2).

Therefore, according to the defect inspection apparatus 10 of the first embodiment, high-resolution and high-precision defect inspection can be performed regardless of the type of the wafer 11 (the pitch p of the repetitive pattern). In the above-described first embodiment, the image pickup device 26 is tilted by the same angle in conjunction with the tilt of the inspection stage 12, and the inclination angle α of the imaging surface and the inclination angle β of the wafer 11 are always adjusted to be equal. However, the present invention is not limited to this configuration.

For example, the tilt of the image sensor 26 may be performed stepwise. In this case, there is an angle range in which the imaging element 26 is not tilted even when the inspection stage 12 is tilted. This angle range is preferably set to a range in which the resolution can be reduced even if the shape of the image 11b formed on the imaging surface changes. In addition, a table that associates the tilt angle range of the inspection stage 12 with the tilt angle of the image sensor 26 is created in advance, and the table is referred to according to the tilt angle of the inspection stage 12 (contents of the recipe). The image sensor 26 may be controlled in this way. The tilt angle of the image sensor 26 can also be registered as a recipe.

(Second Embodiment) The second embodiment of the present invention
This corresponds to claims 3 and 4. The defect inspection apparatus 30 according to the second embodiment has different pitches p formed on the wafer 11.
As shown in FIG. 4, an image sensor 31 and an inspection stage 32 are provided in place of the image sensor 26 and the inspection stage 12 of the above-described defect inspection device 10 (FIG. 1). With the new light receiving section
(34 to 36). Hereinafter, a configuration different from the defect inspection apparatus 10 (FIG. 1) will be described.

In the defect inspection apparatus 30 of the second embodiment, the inspection stage 32 is fixed in a horizontal state. Further, the image sensor 31 is provided with an optical axis O of the light receiving section (24, 25, 31).
3 is arranged so that the angle α1 of the imaging surface with respect to 3 is equal to the angle β1 of the wafer 11 with respect to the optical axis O2 (α1 = β1). Angle β of wafer 11 with respect to optical axis O2
1 is approximately 90 degrees. The members supporting the light receiving sections (24, 25, 31) are not shown.

The newly provided light receiving units (34 to 36) are decentered optical systems each including a concave reflecting mirror 34, an imaging lens 35, and an image pickup device 36, and the light receiving units (24, 25, 31) )
Is a two-sided telecentric system similar to. This light receiving section
The members supporting (34-36) are also not shown. The light receiving sections (34 to 36) are provided with the light receiving sections (24,
25, 31) and the illumination unit 13. That is, the wafer 11 with respect to the optical axis O4 of the light receiving portions (34 to 36)
Is smaller than the angle β1 of the wafer 11 with respect to the optical axis O2 of the light receiving section (24, 25, 31) (β2 <
β1).

The image sensor 36 of the light receiving section (34 to 36)
Are arranged such that the angle α2 of the imaging surface with respect to the optical axis O5 of the light receiving units (34 to 36) is equal to the angle β2 of the wafer 11 with respect to the optical axis O4 (α2 = β2). In the defect inspection device 30 of the second embodiment, two light receiving units (24, 2
5, 31) and (34 to 36), it is possible to simultaneously inspect repetitive patterns having different pitches p formed in the inspection area 11a (FIG. 2A) of the wafer 11.

The light receiving section (24, 25, 31) has a wafer 11
The diffracted light L2 traveling in the direction of the angle β1 is guided from the inspection area 11a. Therefore, an image of the inspection area 11a is formed on the imaging surface of the imaging element 31 by the diffracted light L2 having the diffraction angle β1. The shape of the image of the inspection area 11a by the diffracted light L2 is substantially similar to the shape of the inspection area 11a (see FIG. 2C). This is because the angle α1 of the imaging surface of the image sensor 31 is equal to the angle β1 of the wafer 11.

The light receiving sections (34 to 36) have the wafer 1
The diffracted light L3 that travels in the direction of the angle β2 is guided from the one inspection area 11a. Therefore, the inspection area 11a due to the diffracted light L3 having the diffraction angle β2 is provided on the imaging surface of the imaging element 36.
Is formed. Inspection area 11a by diffracted light L3
Is also substantially similar to the shape of the inspection area 11a (see FIG. 2C). This is because the angle α2 of the imaging surface of the image sensor 36 is equal to the angle β2 of the wafer 11.

As described above, according to the defect inspection device 30 of the second embodiment, the shape of the image formed by the light receiving portions (24, 25, 31) and the shape of the image formed by the light receiving portions (34 to 36) are different. 2A can be made substantially similar to the shape of the inspection area 11a (FIG. 2A), the pitch p of the repetitive pattern formed in the inspection area 11a of the wafer 11 can be reduced. A highly accurate defect inspection can be performed regardless of the above.

Usually, the light receiving units (34 to 36) are more repetitive patterns inspected using the light receiving units (24, 25, 31).
The pitch of the repeated pattern inspected using
The pitch is narrow. In the second embodiment, the light receiving unit (34) is provided between the light receiving unit (24, 25, 31) and the illumination unit 13.
Although the example of the defect inspection device 30 in which the components (.about.36) are arranged has been described, the present invention is not limited to this configuration.

For example, as in a defect inspection apparatus 40 shown in FIG.
(23, 45, 46) may be arranged. This light receiving section (23,
Reference numerals 45 and 46) decenter optical systems each including the concave reflecting mirror 23, the imaging lens 45, and the image pickup device 46,
4, 25, 31). The angle β3 of the wafer 11 with respect to the optical axis O6 of the light receiving sections (23, 45, 46) is equal to the optical axis O2 of the light receiving sections (24, 25, 31).
Smaller than the angle β1 of the wafer 11 with respect to (β3 <β
1). Further, the image sensor 46 of the light receiving section (23, 45, 46)
Are arranged such that the angle α3 of the imaging surface with respect to the optical axis O7 is equal to the angle β3 of the wafer 11 with respect to the optical axis O6 (α3 = β3).

Therefore, in the defect inspection apparatus 40, the inspection area 11a (FIG. 2A) of the wafer 11 is formed by the two light receiving sections (24, 25, 31) and (23, 45, 46). Repeated patterns having different pitches p can be inspected simultaneously. Further, the shape of the image of the inspection area 11a formed by the light receiving sections (24, 25, 31) and the light receiving section
Both the shape of the image of the inspection area 11a formed at (23, 45, 46) and the shape of the inspection area 11a (FIG. 2A)
To the wafer 11
The defect inspection can be performed with high accuracy irrespective of the pitch p of the repetitive pattern formed in the inspection area 11a.

In the above embodiment, the light receiving unit of the telecentric system on both sides has been described as an example.
The present invention can also be applied to an apparatus in which both the first side and the imaging element side are not telecentric optical systems.

[0053]

As described above, according to the present invention,
Regardless of the pitch of the repetitive pattern formed in the area to be inspected on the substrate, the area to be inspected is inspected based on a substantially similar image, so that a highly accurate defect inspection can be performed.
Reliability is improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a defect inspection apparatus 10 according to a first embodiment.

FIG. 2 is an explanatory diagram showing an angle β of the wafer 11 with respect to the optical axes O2 and O3 of the defect inspection apparatus 10 and an angle α of an imaging surface of an imaging element 26.

FIG. 3 is a flowchart showing an operation procedure in the defect inspection apparatus 10.

FIG. 4 is an overall configuration diagram of a defect inspection device 30 according to a second embodiment.

FIG. 5 is an overall configuration diagram of another defect inspection apparatus 40.

FIG. 6 is an overall configuration diagram of a conventional device.

[Explanation of symbols]

 10, 30, 40 Defect inspection device 11 Wafer 12 Inspection stage 13 Illumination unit 14 Light receiving unit 15 Image processing device 16 Display device 17 Control device 18 Memory 21 Light source 22 Light guide 23, 24, 34 Concave reflecting mirror 25, 35, 45 Image lens 26, 31, 36, 46 Image sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2F065 AA49 BB01 BB02 CC18 CC25 DD03 FF04 FF48 GG03 HH12 JJ03 JJ08 JJ26 LL01 LL19 LL59 MM04 MM25 PP05 PP13 QQ24 QQ31 QQ38 RR08 SS02 UU02 2G051 AA07 DAB07 DAB08

Claims (4)

[Claims] An illumination unit configured to illuminate a region to be inspected on a substrate; an imaging optical system configured to collect diffracted light from the region to be inspected to form an image of the region to be inspected; An image pickup device for picking up the image formed by the above, a support unit for supporting the substrate, and an adjustment unit for adjusting a relative positional relationship between the support unit, the imaging optical system, and the image pickup device. The adjusting unit adjusts the relative positional relationship so that the shape of the image formed on the imaging surface of the imaging device is substantially similar to the shape of the inspection area. Characteristic defect inspection equipment. 2. The defect inspection apparatus according to claim 1, wherein the imaging optical system is an optical system that is telecentric with respect to the substrate side and the imaging element side, and the adjustment unit is configured to use the imaging optical system. A defect inspection apparatus, wherein the relative positional relationship is adjusted such that an angle of the imaging surface with respect to an optical axis of the system and an angle of the substrate with respect to the optical axis are substantially equal. 3. An illuminating means for illuminating a region to be inspected on a substrate; an imaging optical system for condensing diffracted light from the region to be inspected to form an image of the region to be inspected; An image pickup element for picking up the image formed by the image pickup device, and a support unit for supporting the substrate, wherein the support unit, the image forming optical system, and the image pickup device are arranged with respect to an optical axis of the image forming optical system. While tilting the substrate,
In a positional relationship where the shape of the image formed on the imaging surface of the imaging device is substantially similar to the shape of the inspection area,
A defect inspection device, which is fixedly arranged. 4. The defect inspection apparatus according to claim 3, wherein the imaging optical system is an optical system that is telecentric with respect to the substrate side and the imaging element side, and the support unit and the imaging optical system. And the imaging element are fixedly arranged such that the inclination angle of the imaging surface with respect to the optical axis of the imaging optical system and the inclination angle of the substrate with respect to the optical axis are substantially equal. Defect inspection equipment.