JP2001201461A - Foreign-body inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foreign-body inspection apparatus, in which it is sufficient to perform only one scanning operation of inspection light, even when a substrate to be inspected is large and by which a prescribed foreign body can be inspected in a short time. SOLUTION: In the foreign-body inspecting apparatus, the surface 1a of the substrate 1 to be inspected, held by an inspection stage 2 is irradiated with a light 4 from a light source 5, and a scattered light 8 from the surface 1a of the substrate 1, to be inspected, at this time is detected by linear array sensors 9. The linear array sensors 9 in a plurality of pieces are arranged, in such a way that they are in series in their longitudinal direction and that both end parts of them are overlapped by a prescribed length. The inspection stage 2 or an irradiation optical system 3, which contains the light source 5, is moved rectlinearly in the direction at right angles to the arrangement direction of the linear array sensors 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass substrate incorporated in a liquid crystal display device, a reticle or mask used for printing a circuit pattern on a semiconductor wafer in an LSI manufacturing process, or a product on which a circuit pattern is formed. The present invention relates to a foreign matter inspection apparatus capable of specifying whether foreign matter has adhered to the surface of a substrate to be inspected such as a wafer, and the size and location of the foreign matter.

[0002]

2. Description of the Related Art In recent foreign matter inspection apparatuses, a photodetector for detecting scattered light from the surface of a substrate to be inspected is provided.
For example, a device using a linear array sensor such as a CCD array sensor is being developed. This is because the linear array sensor can directly obtain position information, which is advantageous in signal processing and the like.

[0003]

The linear array sensor is commercially available and has a maximum length of about 3 mm.
Therefore, when inspecting a foreign substance on a substrate having a larger width or length, it was necessary to move the inspection stage for mounting the substrate to be inspected many times, as shown in FIG. . That is, in FIG.
An inspection target substrate 41 such as glass is horizontally mounted on an inspection stage 42 which moves linearly in the X direction and the Y direction orthogonal thereto. Reference numeral 43 denotes an irradiation optical system for irradiating the surface (upper surface) 1a of the inspection target substrate 41 with, for example, laser light 44 as inspection light.
, And a light scanning device 46.
The laser light source 45 is provided above one end of the inspection stage 42 in the X direction. Also, the optical scanning device 4
Numeral 6 is for scanning the laser light 44 from the laser light source 45 in the Y direction as appropriate, and is made of, for example, a galvanomirror.

[0004] 47 indicates a surface 41 of the inspection target substrate 41 when the laser light 44 is irradiated on the inspection target substrate 41.
a is a linear array sensor for detecting the scattered light generated at a.
They are provided along the direction.

In the foreign matter inspection apparatus having the above-described structure, the length of the linear array sensor 47 (the length in the Y direction) is smaller than that of the linear array sensor 47.
Since the length of the inspection target substrate 41 in the Y direction is considerably large,
Irradiation with laser light 44 is performed as follows. That is, 1. The inspection stage 42 is moved while scanning the laser light 44,
As indicated by the reference numeral, the substrate is linearly moved in the X direction and irradiated from one end 41b to the other end 41c of the inspection target substrate 41. 2. Then, the inspection stage 42 is linearly moved in the X direction, as indicated by reference numerals, to return the inspection target substrate 41 to the position shown in FIG. 3. The inspection stage 42 is moved in the Y direction as indicated by the reference numeral to set a range to be scanned, and
The inspection stage 42 is linearly moved in the direction of the arrow X while scanning 4, and the next irradiation is performed to perform the inspection. 4. Hereinafter, 1. ~ 3. By repeating the above operations, the entire surface of the inspection target substrate 41 is inspected.

As described above, conventionally, when the size of the substrate 41 to be inspected becomes large, the inspection stage 42 must be moved many times, and the operation is troublesome, and the time required for the foreign substance inspection increases. was there.

On the other hand, it is conceivable to use a camera lens as a photodetector and reduce the image of the substrate 41 to be inspected for inspection. However, the inspection is required in spite of the complicated structure of the optical system. There is an inconvenience that time cannot be reduced so much.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems, and has as its object to scan inspection light only once even if the substrate to be inspected is large, and to obtain a predetermined foreign substance in a short time. An object of the present invention is to provide a foreign substance inspection device capable of performing an inspection.

[0009]

In order to achieve the above object, according to the present invention, light from a light source is applied to the surface of an inspection target substrate held on an inspection stage, and the surface of the inspection target substrate at that time is irradiated. In a foreign matter inspection device configured to detect scattered light from a linear array sensor, a plurality of the linear array sensors are arranged in series in the length direction and both ends thereof overlap by a predetermined length. In addition, the inspection stage or the irradiation optical system including the light source is linearly moved in a direction orthogonal to the direction in which the linear array sensor is arranged.

As described above, since a plurality of linear array sensors are arranged in the length direction thereof, even if the linear array sensor alone is not as long as the width or the length of the substrate to be inspected, a large substrate can be used only. Inspection can be performed by one scan. In the above configuration, adjacent linear array sensors overlap each other at both ends thereof.The linear array sensor has a structure in which sensor portions are not formed at both ends and a so-called dead zone exists due to its structure. This is because the dead zone is eliminated by overlapping.

[0011]

Embodiments of the present invention will be described with reference to the drawings. 1 and 2 show one embodiment of the present invention. In these figures, reference numeral 1 denotes an inspection target substrate such as glass, which is horizontally mounted on an inspection stage 2 which moves linearly and reciprocally in the X direction. Reference numeral 3 denotes an irradiation optical system for irradiating the surface 1a of the inspection target substrate 1 with, for example, a laser beam 4 as inspection light.
It comprises a laser light source 5 and an optical scanning device 6. The laser light source 5 is provided above one end of the inspection stage 2 in the X direction. The optical scanning device 6 is formed of, for example, a galvanometer mirror, and scans the laser light 4 emitted from the laser light source 5 in the Y direction orthogonal to the X direction as appropriate, thereby scanning the width of the inspection target substrate 1 on the inspection stage 2. It is configured to scan in the entire direction (Y direction orthogonal to the X direction).

Reference numeral 7 denotes the surface 1 of the inspection target substrate 1 when the scanned laser beam 4 is irradiated on the inspection target substrate 1.
This is a detection optical system for detecting the scattered light 8 generated at a, and includes a plurality of linear array sensors 9 and a plurality of condenser lens arrays 10 provided correspondingly. The linear array sensor 9 is, for example, a CCD array sensor, and is linearly provided along the Y direction. More specifically, the linear array sensor 9
Are arranged in series in the length direction and perpendicular to the X direction in which the inspection stage 2 moves, and at least the same as the length in the width direction (length in the Y direction) of the substrate 1 to be inspected, more preferably Inspection stage 2 width direction length (Y direction length)
A plurality is arranged so as to be the same as. Each CC
Since the D array sensor 9 does not have sensor portions at both ends in the length direction and has a so-called dead zone portion,
To cover this, both ends are overlapped so that a dead zone does not occur. Therefore, as shown in FIG. 1, the respective CCD array sensors 9 are arranged so as to be staggered with each other in a plan view. The condensing lens array 10 is provided below the linear array sensor 9 so as to correspond to each linear array sensor 9, and is formed by arraying, for example, a refractive index distribution lens such as a SELFOC lens (trade name).

The foreign substance inspection apparatus is controlled by an arithmetic and control unit such as a personal computer for controlling the entire apparatus, and the output of the CCD array sensor 9 is processed by the arithmetic and control unit to determine the position of the foreign substance and its position. It is configured so that the size can be specified.

In the foreign substance inspection apparatus having the above-described configuration, the length of the inspection target substrate 1 in the width direction (Y direction) is adjusted to match the length.
The laser beam 4 can be scanned in the Y direction by the optical scanning device 6, and a plurality of CCD array sensors 9 are arranged in series to match the length of the inspection target substrate 1 in the width direction (Y direction). Inspection stage 2
Is moved from the one end side to the other end side only once, linearly in the X direction orthogonal to the Y direction, to sequentially scan the entire surface 1a of the inspection target substrate 1 with the laser light 4. Then, the scattered light 8 generated on the surface 1a can be sequentially detected by the plurality of CCD array sensors 9. Then, by processing the output of each CCD array sensor 9 in the arithmetic and control unit, information on the foreign matter such as presence / absence of foreign matter, its location and size can be obtained, and foreign matter inspection on the inspection target substrate 1 can be performed. .

FIG. 3 shows another embodiment of the present invention. In this embodiment, an irradiation optical system 3 provided at one end side information of an inspection stage 2 is condensed with a laser pattern projector 11. The lens array 12 is used. That is, the laser pattern projector 11 is used as a laser light source, and its light emitting point 11a
And a laser beam 4A that spreads linearly in the Y direction (the width direction of the inspection stage 2) with the center as the center, and a commercially available product such as a LASIRIS collimator line projector is available. The condenser lens array 12 is formed by arraying refractive index distribution lenses such as cylindrical lenses, for example, and has a length enough to irradiate the entire width (length in the Y direction) of the inspection target substrate 1. And is interposed in the optical path between the laser pattern projector 11 and the inspection stage 2.

The operation of the foreign matter inspection apparatus configured as described above is the same as that of the first embodiment.
The description is omitted. In this embodiment, a laser pattern projector 11 is used as a laser light source.
Is used, the entire inspection target substrate 1 can be irradiated with the laser beam 4A without providing an optical scanning mechanism such as a galvanometer or a scanning mirror, and the configuration of the irradiation optical system is simplified, and the control thereof is simplified. In addition to being easy, the entire apparatus can be configured at low cost.

In any of the above-described embodiments, the inspection stage 2 is moved in the X direction so that the surface 1a of the substrate 1 to be inspected is irradiated with the laser beam 4 or 4A. Instead, the laser light source 5 or 1
The irradiation optical system 3 including 1 may be linearly moved in the X direction.

[0018]

As described above, according to the present invention, the surface of the inspection target substrate held on the inspection stage is irradiated with light from the light source, and the scattered light from the surface of the inspection target substrate at that time is emitted. In a foreign matter inspection device configured to detect with a linear array sensor, a plurality of the linear array sensors are arranged in series in a length direction thereof and both ends thereof are overlapped by a predetermined length, and the inspection is performed. Since the stage or the light source is configured to move linearly in a direction orthogonal to the arrangement direction of the linear array sensor, even if the inspection target substrate is large,
The inspection light only needs to be scanned once, and a predetermined foreign substance inspection can be performed in a short time.

Therefore, even if the substrate to be inspected becomes large, foreign matter inspection can be performed in a short time, and it is possible to suitably cope with an increase in the size of a liquid crystal display device or a wafer.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an example of the configuration of an optical system of a foreign matter inspection device according to the present invention.

FIG. 2 is a diagram schematically showing a side configuration of the optical system.

FIG. 3 is a perspective view schematically showing another example of the configuration of the optical system of the foreign matter inspection device of the present invention.

FIG. 4 is a diagram for explaining a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inspection board, 1a ... Surface, 2 ... Inspection stage, 3
... irradiation optical system, 4 ... light, 5 ... light source, 8 ... scattered light, 9 ... linear array sensor, 11 ... light source.

Claims (1)

[Claims] 1. A foreign object which irradiates light from a light source onto a surface of a substrate to be inspected held on an inspection stage and detects scattered light from the surface of the substrate to be inspected at that time by a linear array sensor. In the inspection apparatus, a plurality of the linear array sensors are arranged in series in the length direction and both ends thereof are overlapped by a predetermined length, and the irradiation optical system including the inspection stage or the light source is disposed. A foreign matter inspection device characterized by moving linearly in a direction orthogonal to the arrangement direction of the linear array sensor.