JP2003344307A - Optical inspection equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical inspection equipment suitable for reduction in size and contributive to cost reduction will with a crack or a chip can be detected readily on the circumferential surface of a wafer. <P>SOLUTION: The optical inspection equipment is provided with a light irradiating means having a first optical component constituted of a Fresnel lens or a Fresnel reflector for irradiating one side of the wafer with light from a spot light source rendered parallel, a second optical component constituted of a Fresnel lens or a Fresnel reflector and condensing parallel light passing through the outside of the outer circumferential part of the wafer, a first light receiving part receiving light from the second optical component, a first light projecting means for projecting light toward the circumferential surface of the wafer through a projection fiber, and a second light receiving part receiving light reflected on the circumferential surface of the wafer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical inspection device.

[0002]

2. Description of the Related Art Personal computers (personal computers) and mobile phones have been popularized as products that are now indispensable in daily life. It is no exaggeration to say that the evolution of these products is the evolution and development of various semiconductor devices such as CPUs and memories. Further evolution,
It is a well known fact that various semiconductor processes that support the semiconductor device manufacturing process are indispensable for the development.

As a process device, a dry etcher,
Apparatuses such as asher, plasma CVD, sputtering, and ion implantation are known. Among these apparatuses, the apparatus utilizing plasma emission detects the position of the wafer (including detection of the position of the notch and the orientation flat (orientation flat)) before transferring the wafer to the chamber, and then the position (direction). Including)) (Alignment)
Is absolutely necessary.

This is because it is necessary to secure the absolute position of the wafer in the chamber by stabilizing the process condition with respect to the orientation of the wafer crystal and maintaining the uniformity of the plasma by keeping the position of the wafer in the chamber constant. This is because This alignment is an in-apparatus process common to most so-called process apparatuses, and it is almost always equipped with an alignment unit.

[0005]

This alignment is
Normally, the robot once inserts the wafer that came out of the cassette on the loading side into the alignment unit, performs centering and orientation adjustment of the wafer, and when the end signal is sent, the robot again picks up the wafer and carries it to the chamber. Be implemented. However, in order to detect the position of the wafer and the like, it is necessary to incorporate various optical components into the alignment unit, and thus the alignment unit has conventionally been unavoidably large.

On the other hand, it is also important to detect cracks and chips on the peripheral surface of the wafer. This is because if there are cracks or chips, dust is generated, and scratches may be formed on the front and back surfaces of the wafer during polishing of the wafer or formation of the epitaxial layer, or defects may be generated in the epitaxial layer of the wafer.

The present invention has been made in view of the above problems, and an object thereof is to provide an optical inspection apparatus which is suitable for downsizing, contributes to cost reduction, and can easily detect cracks and chips on the peripheral surface of a wafer. There is.

[0008]

An optical inspection apparatus according to a first aspect of the present invention comprises a Fresnel lens or a Fresnel reflecting mirror for collimating light from a point light source and irradiating the light onto one surface of the wafer. A light irradiation means having an optical component of
A second optical component configured of a Fresnel lens or a Fresnel reflecting mirror for collecting parallel light passing outside the outer peripheral portion of the wafer, a first light receiving unit for receiving light from the second optical component, and the wafer A first light projecting means for projecting light toward the peripheral surface of the wafer through the light projecting fiber, and a second light receiving portion for receiving the light reflected by the peripheral surface of the wafer through the light receiving fiber. It is characterized by being provided. In this case, each of the first optical component and the second optical component constitutes a telecentric system.

The "inspection of the wafer" is performed for the purpose of centering the wafer, adjusting the orientation of the wafer crystal, detecting cracks and chips on the peripheral surface of the wafer, and the like. Further, the “point light source” does not need to be a complete point light source, and may be a point light source substantially, and may be a point light source according to desired accuracy. The “parallel light” may be substantially parallel light, and may be parallel light according to desired accuracy. Further, the “light receiving section” is not particularly limited, but a sensor such as CCD is used. Further, it is preferable to provide a rotating means for rotating the wafer in the circumferential direction. This is because the defect inspection of the wafer can be easily performed by rotating the wafer in the circumferential direction by the rotating means. Further, it is preferable to use an optical fiber unit integrated with the light emitting and receiving as the light emitting fiber and the light receiving fiber. As the optical fiber unit, for example, a light projection and light reception fiber array is a random type (light projection and light reception fibers are randomly arranged), a half type (two light projection and light reception fibers (for example, left and right)). The donut type (the light-transmitting and light-receiving fibers are separately arranged in the central portion and the peripheral portion) can be used.

According to this optical inspection apparatus, since the light made into the parallel light by the first optical component is applied to one surface of the wafer, the distance between the first optical component and the wafer can be freely set. become. Further, since the second optical component collects the parallel light that passes outside the outer peripheral portion of the wafer, the distance between the first optical component and the wafer can be freely set. If necessary, a reflecting mirror may be incorporated to bend the optical path. As a result, according to this optical inspection apparatus, it is possible to realize an optical inspection apparatus which has a high degree of freedom in the arrangement of optical components and contributes to downsizing and cost reduction. Further, by irradiating the peripheral surface of the wafer with light from the light projecting fiber and receiving the reflected light with the light receiving fiber, cracks and chips on the peripheral surface of the wafer can be easily detected.

An optical inspection device according to a second aspect is the optical inspection device according to the first aspect.
In the optical inspection apparatus described above, at least one of the first optical component and the second optical component is rectangular. Here, it is preferable that the rectangular optical component is arranged such that its longitudinal direction corresponds to the diametrical direction of the wafer, and in that case, the light receiving portion has a one-dimensional sensor corresponding to the rectangular optical component. It is preferable.

According to this optical inspection apparatus, at least one of the first optical component and the second optical component is rectangular, so that the optical inspection apparatus can be made even smaller and less expensive. This is because the optical component itself can be miniaturized and the cost can be reduced by making the optical component rectangular and removing a portion unnecessary for inspection.

An optical inspection apparatus according to a third aspect of the present invention is an optical inspection apparatus having a first optical component including a Fresnel lens or a Fresnel reflecting mirror for collimating light from a point light source and irradiating the parallel light onto one surface of the wafer. A second optical component comprising an irradiating means and a Fresnel lens or a Fresnel reflecting mirror for condensing light reflected on one surface of the wafer; and a second optical component comprising a Fresnel lens or a Fresnel reflecting mirror. A third optical component that collimates the light, a first light receiving unit that receives the parallel light from the third optical component, and a light projecting fiber that projects toward the peripheral surface of the wafer. It is characterized by comprising a light projecting means for emitting light and a second light receiving portion for receiving the light reflected by the peripheral surface of the wafer through a light receiving fiber. In this case, each of the first optical component and the second optical component constitutes a telecentric system. Further, the second optical component and the third optical component form a both-side telecentric system.

The "wafer inspection" is performed for the purpose of centering the wafer, adjusting the orientation of the wafer crystal, reading the ID, and detecting cracks and chips on the peripheral surface of the wafer. Further, the “point light source” does not need to be a complete point light source, and may be a point light source substantially, and may be a point light source according to desired accuracy.
The “parallel light” may be substantially parallel light, and may be parallel light according to desired accuracy. further,
The "light receiving section" is not particularly limited, but a sensor such as CCD is used. Further, it is preferable to provide a rotating means for rotating the wafer in the circumferential direction. This is because the defect inspection of the wafer can be easily performed by rotating the wafer in the circumferential direction by the rotating means. Further, it is preferable to use an optical fiber unit integrated with the light emitting and receiving as the light emitting fiber and the light receiving fiber.
As the optical fiber unit, for example, a light projection and light reception fiber array is a random type (light projection and light reception fibers are randomly arranged), a half type (two light projection and light reception fibers (for example, left and right)). The donut type (the light-transmitting and light-receiving fibers are separately arranged in the central portion and the peripheral portion) can be used.

According to this optical inspection apparatus, since the light made into the parallel light by the first optical component is applied to one surface of the wafer, the distance between the first optical component and the wafer can be freely set. become. Further, since the both-side telecentric system is constituted by the second and third optical parts, the distance between the second optical part and the wafer and the distance between the third optical part and the light receiving portion can be freely set. It can be set. In addition,
If necessary, a reflecting mirror can be incorporated to bend the optical path. As a result, according to this optical inspection apparatus, it is possible to realize an optical inspection apparatus which has a high degree of freedom in the arrangement of optical components and contributes to downsizing and cost reduction. Further, by irradiating the peripheral surface of the wafer with light from the light projecting fiber and receiving the reflected light with the light receiving fiber, cracks and chips on the peripheral surface of the wafer can be easily detected.

The optical inspection device according to claim 4 is the optical inspection device according to claim 3.
In the optical inspection apparatus described above, at least one of the first optical component, the second optical component, and the third optical component is rectangular. Here, it is preferable that the rectangular optical components are arranged so that the longitudinal direction thereof corresponds to the diameter direction of the wafer. According to this optical inspection device, the first optical component, the second optical component, and the third optical component
Since at least one of these optical components is rectangular, the optical inspection device can be further miniaturized and reduced in cost. This is because the optical component itself can be miniaturized and the cost can be reduced by making the optical component rectangular and removing a portion unnecessary for inspection.

The optical inspection device according to claim 5 is the optical inspection device according to claim 3.
Alternatively, in the optical inspection device according to the fourth aspect, the first optical component simultaneously serves as the second optical component. According to this optical inspection device, since the first optical component also serves as the second optical component, the number of parts constituting the optical inspection device can be reduced, and the optical inspection device can be further downsized and inexpensive. It will be possible.

The optical inspection device according to claim 6 is the optical inspection device according to any one of claims 3 to 5.
In any one of the optical inspection devices described above, a stop is provided at or near a focal position of the second optical component. Here, the "focal position of the second optical component" means the focal position on the image side. According to this optical inspection device, since the diaphragm is provided at or near the focal position of the second optical component, the contrast and resolution of the observed image can be improved.

An optical inspection apparatus according to a seventh aspect of the present invention is an optical inspection apparatus having a first optical component including a Fresnel lens or a Fresnel reflecting mirror that collimates light from a point light source and irradiates it onto one surface of the wafer. A second optical component configured by an irradiation unit and a Fresnel lens or a Fresnel reflecting mirror to collect parallel light passing outside the outer peripheral portion of the wafer, and a first light receiving unit for receiving light from the second optical component. And a third optical component configured by a Fresnel lens or a Fresnel reflecting mirror for condensing light reflected on one surface of the wafer, and a light from the third optical component configured by a Fresnel lens or a Fresnel reflecting mirror. A fourth optical component for making parallel light;
Second light receiving portion for receiving parallel light from the optical component, light projecting means for projecting light toward the peripheral surface of the wafer via the light projecting fiber, and light reflected on the peripheral surface of the wafer. And a third light receiving section for receiving the light through the light receiving fiber. In this case, each of the first optical component and the second optical component constitutes a telecentric system. Further, the third optical component constitutes a telecentric system, and the third optical component and the fourth optical component constitute a double-sided telecentric system.

The "inspection of the wafer" here includes the centering of the wafer, the orientation adjustment of the wafer crystal, the reading of the ID,
The purpose is to detect cracks and chips on the peripheral surface of the wafer. Further, the “point light source” does not need to be a complete point light source, and may be a point light source substantially, and may be a point light source according to desired accuracy. The “parallel light” may be substantially parallel light, and may be parallel light according to desired accuracy. Further, the “light receiving section” is not particularly limited, but a sensor such as CCD is used. Further, it is preferable to provide a rotating means for rotating the wafer in the circumferential direction. This is because the defect inspection of the wafer can be easily performed by rotating the wafer in the circumferential direction by the rotating means. Further, it is preferable to use an optical fiber unit integrated with the light emitting and receiving as the light emitting fiber and the light receiving fiber. As the optical fiber unit, for example, a light projection and light reception fiber array is a random type (light projection and light reception fibers are randomly arranged), a half type (two light projection and light reception fibers (for example, left and right)). The donut type (the light-transmitting and light-receiving fibers are separately arranged in the central portion and the peripheral portion) can be used.

According to this optical inspection device, the actions and effects of claims 1 and 3 can be obtained at the same time, and only one light irradiation means is required. Further, by irradiating the peripheral surface of the wafer with light from the light projecting fiber and receiving the reflected light with the light receiving fiber, cracks and chips on the peripheral surface of the wafer can be easily detected.

The optical inspection device according to claim 8 is the optical inspection device according to claim 7.
In the optical inspection apparatus described above, the first optical component is simultaneously the third optical component. According to this optical inspection device, the first optical component is the third
Since it also serves as the optical component, the optical inspection device can be further downsized and reduced in cost.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION 1. Overall Configuration FIG. 1 is a block diagram of an optical inspection apparatus according to an embodiment, and FIG. 2 is a schematic enlarged view of a wafer suction plate of the optical inspection apparatus of FIG. 1 and its vicinity. This optical inspection apparatus includes a wafer suction plate 10 for sucking a wafer W by vacuum suction by a vacuum pump 11, an XY table 20 for moving the wafer suction plate 10 in an XY plane, and the wafer suction plates 10 and XY. A rotary table (rotating means) 30 for rotating the table 20 around a predetermined axis, and a position detection optical system 40 for optically detecting the position of the wafer W,
An ID reading optical system 50 for optically detecting the ID of the wafer W, a defect detecting optical system 60 for detecting cracks and chips on the peripheral surface of the wafer W, a position detecting optical system 40, an ID reading optical system 50, and A display unit 70 that displays an optical image of the wafer W obtained by the defect detection optical system 60, an encoder 80 that detects the amount of rotation of the rotary table 30, and an overall operation of the optical inspection system. Processor 9
It has 0 and.

According to this optical inspection apparatus, the vacuum pump 1
Wafer W on wafer suction plate 10 by vacuum suction by 1.
Is vacuum-sucked, the position detection optical system 40 optically detects the position of the wafer W (including the positions of notches and orientation flats), and the positional deviation is corrected by operating the XY table 20 and / or the rotary table 30 ( The crystal orientation can be adjusted). Further, the ID formed on the main surface of the wafer W can be optically detected and read by the ID reading optical system 50. Further, the defect detection optical system 60 can detect defects (cracks or chips) on the peripheral surface of the wafer W.

The configuration of the essential parts of the present invention will be described below.

2. Configuration of essential parts of the present invention This optical inspection apparatus includes a position detection optical system 40, an ID reading optical system 50, and a defect detection optical system 60. Hereinafter, the position detecting optical system 40, the ID reading optical system 50, and the defect detecting optical system 60 will be mainly described.

A. Position Detection Optical System 40 (1) Configuration FIG. 3 shows the position detection optical system 40. Light source 40
Although a is not particularly limited as a, an LED is used. The LEDs are used for downsizing and cost reduction of the position detecting optical system 40. The light from the light source 40a is designed to be a substantial point light source. For example, an aperture (not shown) is installed in front of the light source 40a, and the light emitted from the light source 40a passes through the aperture to become a substantial point light source. A halogen lamp, a xenon lamp, or other light source may be used as a light source, and an optical fiber or the like may be used to form a substantial point light source.

The light from the point light source is directed to the outer peripheral portion (one surface) of the wafer W. A Fresnel lens 40b is installed in the middle of the Fresnel lens 40b.
The light from the point light source is collimated by b. That is,
The Fresnel lens 40b constitutes a telecentric system. The Fresnel lens 40b is not particularly limited, but has a rectangular shape and is installed such that its longitudinal direction corresponds to the diameter direction of the wafer W. Fresnel lens 40
The reason why b is rectangular is that the Fresnel lens itself can be made small, and the position detection optical system 40 can be made compact and inexpensive. When the Fresnel lens 40b is rectangular, it is preferable to avoid the central portion of the ring-shaped lens as shown in FIG. In place of the Fresnel lens 40b, a rectangular Fresnel reflecting mirror is used, although not particularly limited,
The outer peripheral portion of the wafer W may be irradiated with parallel light. Also in this case, it is preferable to avoid the central portion of the ring-shaped reflecting mirror.

The Fresnel lens 40 sandwiching the wafer W.
A reflecting mirror (total reflecting mirror) 40c is installed at a position facing b. The reflecting mirror 40c is installed at an angle of 45 degrees with respect to the main surface of the wafer W. The reflecting mirror 40c has a function of reflecting the light from the Fresnel lens 40b in the radiation direction of the wafer W in parallel with the main surface of the wafer W. By inserting this reflecting mirror 40c, the optical path can be bent. The reflecting mirror 40c is not essential. A Fresnel reflector or Fresnel lens may be installed at the position of the reflector 40c. By doing so, the reflecting mirror having only the function of reflecting light can be omitted, and the number of parts of the position detection optical system 40 can be reduced.

A Fresnel reflecting mirror 40d is provided so as to face the reflecting mirror 40c in the radiation direction of the wafer W. The Fresnel reflecting mirror 40d has a function of reflecting the light from the reflecting mirror 40c downward and condensing the light. The Fresnel reflecting mirror 40d is not particularly limited, but is rectangular and is installed so that its longitudinal direction corresponds to the diameter direction of the wafer W. The reason why the Fresnel reflecting mirror 40d is rectangular is that the Fresnel reflecting mirror itself can be made small, and the position detection optical system 40 can be made compact and inexpensive.
A Fresnel lens may be used instead of the Fresnel reflecting mirror 40d.

A sensor 40e is provided at or near the focal position of the Fresnel reflecting mirror 40d. This sensor 4
0e receives the light from the Fresnel reflecting mirror 40d and outputs an electric signal corresponding to the received light. The sensor 40e in this case is not particularly limited, but it is preferable to use a line sensor (one-dimensional sensor). When the line sensor is used, it is preferable that each sensor (CCD or the like) forming the line sensor is arranged corresponding to the radiation direction of the wafer W as shown in FIG. In this case, the position of the wafer W is detected depending on which position of the sensor receives the light.

The position detection optical system 40 described above is used for centering the wafer W and detecting the notch or orientation flat of the wafer W to adjust the orientation. Hereinafter, an example of the specific method will be described. (2) Method 1) As shown in FIG. 3, after the wafer W is vacuum-sucked on the wafer suction plate 10, the Fresnel lens 40b is moved from the light source 40a.
The wafer W is rotated while irradiating light toward the outer peripheral portion of the wafer W through. 2) In this case, the light passing outside the outer peripheral portion of the wafer W is received by the sensor 40e via the reflecting mirror 40c and the Fresnel reflecting mirror 40d, but if there is a positional deviation, the line sensor output as a whole is shown in FIG. As shown, it becomes a sine wave or a cosine wave. In the figure, A indicates the sensor output of the notch or the orientation flat portion. The positional deviation in the XY directions is obtained from the amplitude of the sensor output, the positional deviation of the crystal orientation is obtained from the sensor output position of the notch or the orientation flat portion, and the control circuit 80 determines the positional deviation in the XY table 20 and the rotary table. The position shift is corrected by moving 30 accordingly.

B. ID Reading Optical System 50 (1) Configuration FIG. 6 shows the ID reading optical system 50. Light source 50
Although a is not particularly limited as a, an LED is used. The LED is used in order to reduce the size and cost of the ID reading optical system 50. The light from the light source 50a is designed to be a substantial point light source. For example, an aperture (not shown) is installed in front of the light source 50a,
The light emitted from the light source 50a passes through this aperture to become a substantial point light source.
A halogen lamp, a xenon lamp, or other light source may be used as a light source, and an optical fiber or the like may be used to form a substantial point light source. Also, this light source 5
Another aperture 50b having a relatively large diameter near 0a
Is installed, and stray light is removed by the aperture 50b.

The light from the point light source is emitted parallel to the main surface of the wafer W and toward the center of the wafer W. The light emitted from this point light source is a semi-transparent mirror (beam splitter) 5
0c and hits the Fresnel reflecting mirror 50d installed above the wafer W to bend the optical path downward,
It is considered as parallel light. In other words, the Fresnel reflecting mirror 50d constitutes a telecentric system. Then, the parallel light from the Fresnel reflecting mirror 50d is applied to the main surface of the wafer W from the normal direction of the wafer W. This Fresnel reflector 50
Although not particularly limited, d has a rectangular shape and is installed such that its longitudinal direction corresponds to the arrangement direction of the characters and symbols forming the ID. The Fresnel reflecting mirror 50d is rectangular because the Fresnel reflecting mirror itself can be made small and the ID reading optical system 50 can be made compact. When the Fresnel reflecting mirror 50d is rectangular, it is preferable that the light from the Fresnel reflecting mirror 50d can cover the entire ID. Also, the Fresnel reflector 50d
When is rectangular, it is preferable to avoid the central portion of the annular reflecting mirror. Further, the Fresnel reflecting mirror 50d may be replaced by a rectangular Fresnel lens, which is not particularly limited, and the main surface of the wafer W may be irradiated with parallel light. Also in this case, it is preferable to avoid the central portion of the ring-shaped lens.

On the main surface of the wafer W, the Fresnel reflecting mirror 50 is provided.
In addition to the parallel light from d, diffused light from the auxiliary light source 50e provided above the wafer W is irradiated.
By providing this auxiliary light source 50e, the contrast and resolution can be improved depending on the state of the ID number. The auxiliary light source 50e is not particularly limited, but an LED, a white light source, or the like is used. in this case,
It is preferable to use LEDs. This is because the ID reading optical system 50 can be made compact and inexpensive.

The light radiated to the main surface of the wafer W and reflected by the main surface of the wafer W returns to the Fresnel reflecting mirror 50d and the light path is bent to be converged light, hits the semi-transparent mirror 50c, and the light path is bent downward. A diaphragm (spatial filter) 50f is provided at the focal position of the Fresnel reflecting mirror 50d. It is preferable that the diaphragm 50f is a variable diaphragm and the control circuit 80 can change the opening of the diaphragm 50f. In this way, the contrast and resolution can be freely selected.

The light that has passed through the diaphragm 50f is reflected by the diaphragm 50.
The light enters the Fresnel lens 50g provided below f. The Fresnel lens 50g has a function of converting incident light into parallel light. That is, the Fresnel lens 50g constitutes a telecentric system. Further, the Fresnel lens 50g and the Fresnel reflecting mirror 50d constitute a both-side telecentric system. The Fresnel lens 50g is not particularly limited, but has a rectangular shape whose longitudinal direction is ID.
It is installed so as to correspond to the arrangement direction of the characters and symbols that make up. The reason why the Fresnel lens 50g is rectangular is
This is because the Fresnel lens itself can be made small, and the ID reading optical system 50 can be made inexpensive and compact. When the Fresnel lens 50g has a rectangular shape, it is preferable to cover the entire ID. Also,
When the Fresnel lens 50g is rectangular, it is preferable to avoid the central portion of the annular lens. Further, the Fresnel lens 50g may be replaced by a rectangular Fresnel reflecting mirror, although not particularly limited thereto. Also in this case, it is preferable to avoid the central portion of the ring-shaped reflecting mirror. Needless to say, when using the Fresnel reflecting mirror, it is necessary to change the arrangement of the sensor 50h described later.

A sensor 5 is provided below the Fresnel lens 50g.
0h is provided. The sensor 50h receives light from the Fresnel lens 50g and outputs an electric signal corresponding to the received light. The sensor 50g in this case is not particularly limited, but it is preferable to use a two-dimensional sensor. This is because when the line sensor is used, it is necessary to scan the line sensor for reading the ID.

The ID reading optical system 5 constructed as described above.
0 is used to detect the ID of the wafer W.

(2) Method 1) As shown in FIG. 7, on the wafer W, an ID is usually attached near the notch or orientation flat. This ID reading is performed after position adjustment (alignment). 2) This ID reading is performed automatically, and the read I
D is output to the outside.

C. Defect Detection Optical System 60 (1) Configuration FIG. 8 shows this defect detection optical system 60. The defect detection optical system 60 includes an optical fiber unit 61. The optical fiber unit 61 includes a light projecting optical fiber 62 having a projection light path 62a and a light receiving optical fiber 63 having a reflection light path 63a. As shown in FIG. 9, this optical fiber unit 61 has a light projecting optical fiber 62 arranged in the center, a light receiving optical fiber 63 arranged around it, and they are integrally bundled by a synthetic resin or the like. That is, the optical fiber unit 61 is a donut type light emitting and receiving integrated optical fiber unit. Then, as shown in FIG. 8, one optical fiber unit 61 is arranged toward the center of the peripheral surface of the wafer W. Note that, as shown in FIG. 9, a plurality of optical fiber units 61 may be arranged along the peripheral surface of the wafer W. In either case, it is preferable to set the tip of the optical fiber unit 61 at a distance that maximizes the amount of received light.

Further, in the apparatus of this embodiment, a filter device and a light source (not shown) are installed at the end of the light projecting optical fiber 62 opposite to the end on the wafer W side. The filter device is configured such that the filter can be attached and detached, and allows light from the light source, for example, white light, to be selected as light having a wavelength most suitable for the material of the surface of the wafer W, that is, light having a highest received light amount. ing. The lamp of the light source may be replaced with a lamp of a specific wavelength such as a halogen lamp or a tungsten lamp without using the filter device.

The processing device 90 connected to the defect detection optical system 60 rotates the turntable 20 after the wafer W is set, turns on the light source, and transmits light to the CCD (light-receiving optical fiber 63 via the light-receiving optical fiber 63. Part: image information based on the amount of light received by (not shown) is displayed on the display part 70. Further, in the processing device 90, when the amount of light received by the light receiving optical fiber 63 is less than or equal to a predetermined value (threshold value), it is determined that the peripheral edge of the wafer W has a defect, and the defect is stored in a predetermined storage unit (not shown). It is also possible to record it.

(2) Method In this defect inspection, after the wafer W is positioned and the ID is read, the rotary table 30 is rotated and the peripheral surface of the wafer W is irradiated with light from the light projecting optical fiber 62. The reflected light is received by the CCD through the light receiving optical fiber 63, photoelectrically converted, and the electric signal is input to the processing device 90. This defect inspection is I
It may be performed before reading D.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention.

[0046]

According to the present invention, it is possible to reduce the cost and size of the optical inspection device and to easily perform the defect inspection of the peripheral surface.

[Brief description of drawings]

FIG. 1 is a block diagram of an optical inspection device according to an embodiment.

FIG. 2 is a schematic configuration diagram of a wafer, an XY table, and a rotary table in the optical inspection device of FIG.

3 is a diagram showing a position detection optical system in the optical inspection device in FIG.

FIG. 4 is a diagram for explaining a positional relationship between a sensor and a wafer in the optical inspection device in FIG.

5 is a diagram showing a sensor output when the wafer is displaced in the optical inspection apparatus of FIG.

6 is a diagram showing an ID reading optical system in the optical inspection device of FIG.

FIG. 7 is a diagram for explaining the position of the ID number on the wafer.

8 is a layout diagram showing a structure and an installation state of an optical fiber unit adopted in the optical inspection device of FIG.

FIG. 9 is a layout diagram showing another installation state of the optical fiber unit.

[Explanation of symbols]

W wafer 40 Position detection optical system 40a light source 40b Fresnel lens (optical component) 40d Fresnel reflector (optical parts) 40e sensor (light receiving part) 50 ID reading optical system 50a light source 50d Fresnel reflector (optical parts) 50g Fresnel lens

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Claims (8)

[Claims] 1. A light irradiating means having a first optical component composed of a Fresnel lens or a Fresnel reflecting mirror for collimating light from a point light source and irradiating the light to one surface of the wafer, and a Fresnel lens or Fresnel. A second optical component configured of a reflecting mirror for collecting parallel light passing through the outside of the outer peripheral portion of the wafer, a first light receiving portion for receiving light from the second optical component, and a peripheral surface of the wafer. A first light projecting means for projecting light through a light projecting fiber, and a second light receiving section for receiving the light reflected by the peripheral surface of the wafer through the light receiving fiber. Optical inspection equipment. 2. The optical inspection apparatus according to claim 1, wherein at least one of the first optical component and the second optical component has a rectangular shape. 3. A light irradiating means having a first optical component composed of a Fresnel lens or a Fresnel reflecting mirror for collimating light from a point light source and irradiating the light onto one surface of the wafer, and a Fresnel lens or Fresnel. A second optical component configured by a reflecting mirror for condensing light reflected on one surface of the wafer, and a third optical component configured by a Fresnel lens or a Fresnel reflecting mirror for collimating light from the second optical component Optical component, a first light receiving portion for receiving parallel light from the third optical component, a light projecting means for projecting light toward a peripheral surface of the wafer via a light projecting fiber, An optical inspection apparatus, comprising: a second light receiving section that receives light reflected by the peripheral surface of the wafer via a light receiving fiber. 4. The optical inspection apparatus according to claim 3, wherein at least one of the first optical component, the second optical component, and the third optical component has a rectangular shape. 5. The third optical component according to claim 3, wherein the first optical component simultaneously serves as the second optical component.
The optical inspection device described. 6. The optical inspection apparatus according to claim 3, wherein a diaphragm is provided at or near a focal position of the second optical component. 7. A light irradiating means having a first optical component composed of a Fresnel lens or a Fresnel reflecting mirror for collimating light from a point light source and irradiating the parallel light to one surface of the wafer, and a Fresnel lens or Fresnel. A second optical component configured of a reflecting mirror for collecting parallel light passing outside the outer peripheral portion of the wafer, a first light receiving portion for receiving light from the second optical component, and a Fresnel lens or a Fresnel reflecting mirror. A third optical component configured to condense the light reflected by the one surface of the wafer, and a fourth optical component configured to include a Fresnel lens or a Fresnel reflecting mirror to convert the light from the third optical component into parallel light.
Optical component, a second light receiving portion for receiving parallel light from the fourth optical component, a light projecting means for projecting light toward a peripheral surface of the wafer through a light projecting fiber, An optical inspection apparatus, comprising: a third light receiving section that receives light reflected by the peripheral surface of the wafer through a light receiving fiber. 8. The optical inspection apparatus according to claim 7, wherein the first optical component simultaneously serves as the third optical component.