JP2019219295A - Wafer inspection device and wafer inspection method - Google Patents

Abstract

To provide a wafer inspection device and a wafer inspection method combining advantages of both of a laser inspection method and an image inspection method.SOLUTION: A wafer inspection device (D) pertaining to the present invention comprises: a laser inspection device (1) having a light source (11) for irradiating a wafer with a laser beam, a detector (12) for detecting secondary light, and a laser inspection unit (15) for inspecting the wafer on the basis of intensity of secondary light; and an image inspection device (2) having an image acquisition device (21) for acquiring an observed image of a surface of the wafer, an image acquisition control unit (23) for controlling the image acquisition device, and an image inspection unit (24) for inspecting the wafer on the basis of the observed image. The laser inspection unit (15) specifies a defect part that the wafer possesses, and the image inspection device (2) sets forth an inspection condition pertaining to the inspection of the wafer on the basis of information pertaining to a defect part specified by the laser inspection unit (15).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wafer inspection device and a wafer inspection method.

  2. Description of the Related Art Conventionally, an inspection apparatus for inspecting a wafer in a semiconductor element manufacturing process for defects such as scratches, dents, protrusions, surface roughness, undulations, and deposits has been widely used. In the manufacturing process of a semiconductor element, the quality of a product is assured and a defect in the manufacturing process is found by specifying the existence of a defect and its attribute using such an inspection apparatus.

  Such an inspection apparatus detects, for example, secondary light such as scattered light or reflected light generated when a wafer is irradiated with laser light, as described in JP-A-2008-241570 (Patent Document 1). An apparatus adopting a laser inspection method for performing inspection by using such a method is used. An apparatus adopting the laser inspection method is excellent in that the entire surface of the wafer can be inspected at once, and the inspection over the entire surface of the wafer can be performed quickly.

  As another example of such an inspection apparatus, an image inspection method described in Japanese Patent Application Laid-Open No. 2007-134498 (Patent Document 2) that performs inspection based on an observation image obtained by observing a wafer surface is employed. The device is used. An apparatus adopting the image inspection method is excellent in that a precise inspection result can be obtained by acquiring an observation image at a magnification capable of sufficiently observing each defective portion.

JP 2008-241570A JP 2007-134498 A

  By the way, the technique such as Patent Document 1 may not be applicable to wafer inspection in some cases. For example, when inspecting a transparent wafer such as a SiC wafer or a GaN wafer, depending on an apparatus employing a laser inspection method, a defect existing on the front surface of the wafer and a defect existing inside or on the back surface of the wafer may occur. Sometimes could not be distinguished.

  On the other hand, in a technique such as Patent Literature 2, it takes a long time to set conditions such as focus adjustment and threshold adjustment for acquiring an observation image to be used for inspection, and as a result, the time required for inspection may be long. Was.

  Therefore, it is desired to realize a wafer inspection apparatus and a wafer inspection method that combine the advantages of the laser inspection system in terms of inspection speed and the advantages of the image inspection system in accuracy.

  A wafer inspection apparatus according to the present invention includes a light source that irradiates a laser beam to a wafer, a detector that detects secondary light in which the laser beam is scattered or reflected by the wafer, and the secondary beam that the detector detects. A laser inspection unit having a laser inspection unit that inspects the wafer based on light intensity, an image acquisition device that acquires an observation image of the surface of the wafer, an image acquisition control unit that controls the image acquisition device, and An image inspection device having an image inspection unit for inspecting the wafer based on the observation image acquired by the image acquisition device, and a laser inspection unit comprising: The image inspection apparatus may determine inspection conditions for the inspection of the wafer based on the information on the defective portion identified by the laser inspection unit. And butterflies.

  Further, the wafer inspection method according to the present invention irradiates the wafer with laser light, detects the secondary light scattered or reflected by the wafer, and scans the wafer based on the intensity of the secondary light. A laser inspection step for inspecting, and an image inspection step of acquiring an observation image of the surface of the wafer and inspecting the wafer based on the acquired observation image, comprising: Identifying a defective portion of the wafer, and determining an inspection condition for obtaining an observation image to be used for specifying the defective portion in the image inspection step, based on information on the defective portion specified in the laser inspection step. It is characterized by.

  According to these configurations, the time required for inspection using the image inspection method, which has excellent accuracy, can be reduced by using the inspection results obtained by the laser inspection method, which has excellent inspection speed, and high-accuracy inspection can be achieved in a short time. can do.

  Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiments described below.

  As one aspect of the wafer inspection apparatus according to the present invention, the image acquisition control unit may include a selected defect specified by the laser inspection unit with respect to at least one selected defect selected from the defect units specified by the laser inspection unit. It is preferable to specify a position as an image acquisition target on the wafer based on the coordinate information of the part so that the observation image includes the selected defect part.

  According to this configuration, the coordinates of the position where the observation image should be obtained can be quickly determined based on the inspection result by the laser inspection method, so that the time required for the inspection can be reduced.

  As one aspect of the wafer inspection device according to the present invention, the image acquisition control unit may be configured so that a difference between a maximum value and a minimum value of luminance in the observation image including the selected defect portion is maximized. It is preferable to perform the focus adjustment described above.

  According to this configuration, since the focus adjustment is performed using the selected defect portion selected from the defect portions specified by the laser inspection method as a clue, the time required for the focus adjustment when acquiring the observation image can be shortened, and the inspection can be performed. Can be shortened.

    As one aspect of the wafer inspection apparatus according to the present invention, the image inspection unit specifies a defective portion of the wafer based on a luminance difference that is a difference between a maximum value and a minimum value of luminance in the observation image. It is preferable that a threshold value of the luminance difference used by the image inspection unit to identify the defective part is determined based on the luminance difference in the observation image including the selected defective part.

  According to this configuration, the threshold value of the defective portion to be recognized as a defective portion in the inspection by the image inspection method can be determined based on the inspection result by the laser inspection method having an excellent inspection speed. The time required can be reduced, and the time required for inspection can be reduced.

  Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, with reference to the drawings.

FIG. 2 is a configuration diagram of a wafer inspection device. FIG. 4 is a flowchart of a wafer inspection method.

  An embodiment of a wafer inspection apparatus and a wafer inspection method using the wafer inspection apparatus according to the present invention will be described with reference to FIGS.

[Configuration of wafer inspection device]
First, the configuration of an embodiment of a wafer inspection apparatus according to the present invention will be described. The wafer inspection device D according to the present embodiment includes a laser inspection device 1, an image inspection device 2, a transport unit 3, a control unit 4, and a display 5 (FIG. 1). Each of the laser inspection device 1 and the image inspection device 2 can receive a wafer to be inspected, and each device performs a wafer inspection.

  The wafer to be inspected by the wafer inspection apparatus D is not particularly limited, but may be, for example, a Si wafer, a SiC wafer, a GaN wafer, or the like. The shape of the wafer is not particularly limited as long as it is generally available on the market, and may be, for example, a circular shape having a diameter of 2 to 10 inches (5.1 to 25.4 cm). However, a positioning reference point (not shown) such as a notch is provided at a part of the circular outer peripheral portion of the wafer, and an angle at which the wafer is rotated by a device (such as a rotation stage 13 described later) that supports the wafer is set. The positioning reference point can be specified as a reference. The wafer is preferably flat over its entire surface, but may have defects such as scratches, dents, protrusions, surface roughness, undulations, and deposits. The wafer inspection apparatus D is an apparatus that performs inspection for the purpose of specifying these defects of the wafer.

  The laser inspection device 1 includes a light source 11, a detector 12, a rotation stage 13, a laser control unit 14, and a laser inspection unit 15.

  The light source 11 is a laser light source configured to irradiate a laser beam to a wafer mounted on the rotary stage 13. The rotary stage 13 is configured to be horizontally movable, and the horizontal movement can change the target position to be irradiated with the laser beam. Further, the light source 11 may be a plurality of laser light sources having different irradiation angles and directions.

  The detector 12 includes a scattered light detector 121 that detects scattered light scattered by the wafer, and a reflected light detector 122 that detects reflected light reflected by the wafer. Each of the scattered light detector 121 and the reflected light detector 122 may be a plurality of detectors. In this embodiment, the scattered light detector 121 receives the scattered light of the laser light irradiated at a low angle. Scattered light detector with increased detection sensitivity of protrusions, scattered light detector that receives scattered light of laser light irradiated at a high angle to increase dent detection sensitivity, and scattered light corresponding to other defects A detector. Further, as the reflected light detector 122, a reflected light detector which receives regular reflection light of laser light irradiated at a high angle to increase the surface roughness and undulation detection sensitivity, and a laser irradiated at a low angle A reflected light detector that receives specularly reflected light to increase the detection sensitivity of defects related to film thickness. In this specification, scattered light and reflected light are collectively referred to as secondary light.

  The rotation stage 13 is configured to be able to place a wafer. Further, the rotary stage 13 is configured to be horizontally movable, rotatable about the axis, and vertically movable along the axis, integrally with the wafer with the wafer mounted thereon. I have.

  The laser controller 14 is an arithmetic device that controls the operations of the light source 11, the detector 12, and the rotating stage 13. The light source 11 controls emission / stop and intensity of laser light. The start and stop of the detector 12 are controlled. The horizontal movement, the rotational movement, and the vertical movement of the rotary stage 13 are controlled.

  The laser inspection unit 15 is an arithmetic unit that performs arithmetic processing for inspecting the wafer based on a signal input related to the intensity of the secondary light detected by the scattered light detector 121 and the reflected light detector 122. A specific inspection method will be described later.

  The image inspection device 2 includes a camera 21 (an example of an image acquisition device), an image inspection stage 22, an image acquisition control unit 23, and an image inspection unit 24.

  The camera 21 is configured to be able to acquire an observation image of a wafer placed on the image inspection stage 22. The camera 21 can acquire an observation image of the entire wafer or acquire an observation image obtained by enlarging a part of the wafer.

  The image inspection stage 22 is configured to be able to place a wafer thereon and to be horizontally movable in parallel with the wafer while the wafer is being placed. The horizontal movement of the image inspection stage 22 controls an area where the camera 21 acquires an image.

  The image acquisition control unit 23 is an arithmetic device that controls the operation of the camera 21 and the image inspection stage 22. The camera 21 controls adjustment of magnification, aperture, sensitivity, focus, and the like, and the image inspection stage 22 controls horizontal and vertical translations.

  The image inspection unit 24 is an arithmetic unit that performs arithmetic processing for inspecting the wafer based on the observation image acquired by the camera 21. A specific inspection method will be described later.

  The transport unit 3 has a function of arranging a wafer in the laser inspection apparatus 1 and the image inspection apparatus 2 so that an inspection can be performed, and a function of transporting a wafer between the laser inspection apparatus 1 and the image inspection apparatus 2. Have. The control unit 4 is an arithmetic unit that controls the entire wafer inspection apparatus D. In particular, the function of mediating the transfer of information between the laser inspection device 1 (the laser control unit 14 and the laser inspection unit 15) and the image inspection device 2 (the image acquisition control unit 23 and the image inspection unit 24), and the laser inspection It has a function of inspecting a wafer in a complex manner based on the inspection results of both the apparatus 1 and the image inspection apparatus 2. The display 5 displays an inspection result by each of the laser inspection device 1 and the image inspection device 2 and a composite inspection result.

[Wafer inspection method]
Next, a wafer inspection method using the wafer inspection apparatus D will be described with reference to FIG.

  In the inspection of the wafer by the wafer inspection device D, first, the laser inspection step S1 by the laser inspection device 1 is performed, and second, the image inspection step S2 by the image inspection device 2 is performed.

  In the laser inspection step S1, a wafer is placed on the rotary stage 13 (S11), and the wafer is irradiated with laser light from the light source 11 (S12). The laser light applied to the wafer generates scattered light and reflected light, and these secondary lights are detected by the corresponding scattered light detector 121 and reflected light detector 122, respectively (S13). At this time, the laser light is scanned over the entire surface of the wafer by horizontally moving the light source 11 and rotating the rotary stage 13 while irradiating the laser light and detecting the secondary light. Inspection is performed on the whole (S14).

  Generally, if the surface to be scanned is a uniform plane, the secondary light will be uniform. However, if there is a discontinuous point on the surface to be scanned, ie, a defect, the secondary light generated by the defect will be different from the uniform plane around the defect. Using this, the laser inspection unit 15 specifies a portion where the intensity of the detected secondary light is different from that of the surroundings as a portion having a defect, that is, a defective portion (S15).

  At this time, the type and intensity of the secondary light generated by the attribute of the defect may change. Therefore, the attribute of the defect can be determined by combining the detection results of the scattered light and the reflected light. The laser inspection unit 15 determines the attribute of each defect by combining the detection results of the secondary light by each detector.

  After the inspection of the entire surface of the wafer, the display 5 displays the inspection result. The displayed inspection results include information such as coordinate information of a portion specified as having a defect, attribute and size of the defect, a defect map indicating a portion where the defect exists, secondary light intensity at each point on the wafer, and the like. Including. Here, the coordinate information is determined by specifying an angle at which the wafer is rotated by the rotating stage 13 based on a positioning reference point provided on the wafer. These inspection results are shared by the image acquisition control unit 23 and the image inspection unit 24 from the laser inspection unit 15 via the control unit 4.

  Next, an image inspection step S2 is performed. In the inspection of the image inspection step S2, first, a step of adjusting the focal length of focus of the camera 21 (an example of inspection conditions) based on a defective portion selected from the defective portions specified in the laser inspection step S1 is performed. Next, a step of adjusting a threshold value (an example of an inspection condition) for specifying a defective portion from the observation image is performed. A defect portion for adjusting the focal length of the focus (hereinafter, referred to as a defect portion for focus adjustment) and a defect portion for adjusting a threshold value (hereinafter, referred to as a reference defect portion) are included in the image acquisition control section 23. Automatically (selecting one with a predetermined attribute and size) or manually by the user.

  Here, the focus adjustment defect part has a certain size and a high possibility of unevenness (for example, the output of a scattered light detector with a higher detection sensitivity for protrusions and a scattered light detector with a higher detection sensitivity for depressions). Is large) is selected. In addition, a reference defect portion is selected that needs to be handled as a defect portion in view of the required quality of the final product. Specifically, based on the inspection result of the laser inspection step S1, the defect to be handled as the defect portion is determined. It is selected from the smallest level (e.g., a shallow depression, a low protrusion, etc.).

  After the step of adjusting the focal length of the focus and the step of adjusting the threshold value, an inspection step of another defective portion is performed.

  In the image inspection step S2, the wafer that has been inspected in the laser inspection step S1 is placed on the image inspection stage 22 of the image inspection apparatus 2 by the transfer unit 3 (S21).

  First, based on the coordinate information and dimensions of the focus adjustment defect specified in the laser inspection step S1, the image acquisition control unit 23 controls the camera 21 so that the focus adjustment defect is included in the image acquisition range of the camera 21. Of the image inspection stage 22 in the horizontal direction (example of the inspection condition) (S22).

  Then, the focus of the camera 21 is adjusted (S23). In adjusting the focal length, in order to make the observation image of the focus adjustment defect portion clear, specifically, the luminance value at the point where the luminance is the maximum and the luminance value at the point where the luminance is the minimum in the observation image The adjustment is performed so that the difference (contrast value) between and is maximized. That is, focus adjustment is performed based on the luminance value detected by the image sensor of the camera 21.

  More specifically, the focus adjustment is performed by an autofocus method under the control of the image acquisition control unit 23. In the present embodiment, a line sensor method is employed as the autofocus method. In the autofocus method, the focal length of the camera 21 when the contrast of the entire observed image is highest is set as the focal length at which the focus is achieved. There is a need.

  In the focus adjustment step (S23) after the focal length is adjusted by the focus adjustment defect portion, a means for measuring the wafer height in real time is used in combination with the wafer thickness variation and the surface warpage. An auto focus process is performed in which the image inspection stage 22 is moved in the vertical direction to automatically adjust the focal length.

  After the focus adjustment, the camera 21 acquires an observation image of the defective portion (S24).

Subsequently, S22 to S24 described above are performed for the reference defect portion, and the image inspection section 24 adjusts a threshold for determining a defect based on the observation image of the reference defect portion.
When the contrast value in the observed image is equal to or more than a certain threshold, the image inspection unit 24 specifies that the defective portion included in the observed image is truly a defective portion. On the other hand, when the contrast value is less than the threshold value, it is specified that the defective portion included in the observed image is not a defective portion. If the threshold value is too high, there is a risk that the recognition of a defective portion is missed. If the threshold value is too low, there is a possibility that a false detection of a defective portion may occur. Therefore, it is necessary to set an appropriate value according to the purpose of inspection. Here, on the basis of the observed image of the reference defect, the reference defect is recognized as a defect, and a defect having a smaller defect level than the reference defect is not recognized as a defect. , A threshold is set.

When the adjustment of the focal length of the focus and the threshold are completed, the above steps S22 to S24 are repeated for other defective portions to acquire a plurality of observation images.
At this time, among the defective portions specified by the inspection in the laser inspection step S1, all the defective portions may be the inspection targets of the image inspection step S2, or it is determined that more precise inspection by the image inspection step S2 is necessary. Only the defective part of the part may be the inspection target in the image inspection step S2. Further, an observation image may be obtained for a part determined to have no defect in the inspection in the laser inspection step S1. In any case, inspection conditions such as focus adjustment determined at the time of the first image acquisition do not need to be significantly changed when acquiring observation images of other parts, so that acquisition of a plurality of observation images can be promptly performed. It can be carried out.

The image inspection unit 24 specifies the attribute and the size of the defective part based on the observation image (S25).
According to the threshold value determined based on the observation result of the reference defect portion, it is specified whether or not the observation image of the defect portion obtained at each part of the wafer is a defect portion to be truly treated as a defect portion. Therefore, only a defective portion having a defect level equal to or higher than the reference defective portion can be handled as a truly defective portion in the image inspection step S2, so that an inspection result that meets the inspection purpose can be obtained.

  After the inspection in the image inspection step S2 is performed for each defective portion specified in the laser inspection step S1, the inspection result is displayed on the display 5. The result of the image inspection step S2 is passed from the image inspection unit 24 to the control unit 4, and the control unit 4 displays the composite inspection result based on the inspection results of both the laser inspection step S1 and the image inspection step S2 on the display 5. indicate.

[Effect of this embodiment]
According to the above-described embodiment, it is possible to realize an inspection that combines the advantages of the laser inspection system in terms of inspection speed and the advantages of the image inspection system in accuracy.

  In the image inspection method, a precise inspection result can be obtained by acquiring an observation image at a magnification that allows sufficient observation of each defective portion. However, it is difficult to inspect the entire surface of the wafer at once.

Also, as described above, it is necessary to perform focus adjustment in the image inspection method. However, when a uniform flat surface such as a portion that does not include a defect of a wafer is targeted for image acquisition, focus adjustment is performed. There is a feature that it is difficult. Therefore, it is common to adjust the horizontal position of the image inspection stage 22 so that at least one defective portion is included in the image acquisition range of the camera 21, and then perform focus adjustment using the defective portion as a clue. . However, when the image inspection apparatus 2 is used alone, it takes time to find a defective portion to be used as a clue, and as a result, the time required for focus adjustment may be long.
Also, when setting a threshold value in the image inspection method, since the attribute and the degree of the defect are unknown at first, acquisition of the observation image and setting of the threshold value for some defects are repeated, or the threshold value for the same defect is determined. It is necessary to determine a threshold value for determining whether or not to be treated as a defective part by resetting the threshold value, for example, so that the time required for the threshold value adjustment may be long.

  From these points, generally, the image inspection method tends to require a longer time for the inspection than the laser inspection method.

  In the present embodiment, the focus adjustment is performed using the focus adjustment defect part selected based on the inspection result of the laser inspection step S1 in advance as a clue. Therefore, the time required to find a defective portion used as a clue can be reduced, and as a result, the time required for focus adjustment can be reduced. In addition, threshold adjustment is performed using a reference defect portion selected based on the inspection result of the laser inspection step S1 in advance as a clue. Therefore, the time required to find a defective portion used as a clue can be reduced, and the defective portion for adjusting the threshold can be uniquely determined. As a result, the time required for the threshold can be reduced. be able to.

  On the other hand, in the laser inspection method, inspection can be performed at once by scanning the entire surface of the wafer with a laser, and the time required for inspection tends to be shorter than in the image inspection method. However, on the other hand, the identification of the attribute and the dimension of the defective portion in the laser inspection method tends to be lower in accuracy than the identification of the attribute and the dimension performed based on the observed image. Further, when inspecting a transparent wafer such as a SiC wafer or a GaN wafer, a defect existing on the front surface of the wafer may not be distinguished from a defect existing inside or on the rear surface of the wafer.

  In the present embodiment, defect attributes are specified in a complex manner by combining inspection results obtained by two different inspection methods, so that highly accurate inspection results can be obtained.

  By adopting these methods, the disadvantage that the inspection time in the image inspection method is lengthened is eliminated, and a highly accurate inspection is realized in a short time.

[Other embodiments]
Another embodiment of the wafer inspection apparatus and the wafer inspection method using the wafer inspection apparatus according to the present invention will be described. The configuration disclosed in each of the following embodiments can be applied in combination with the configuration disclosed in another embodiment as long as no contradiction occurs.

  In the above embodiment, the inspection conditions for obtaining an observation image to be used for inspection of a wafer by the image inspection unit 24 determined based on the information on the defective portion specified by the laser inspection unit 15 are the magnification, focus, and image of the camera 21. The configuration in which the horizontal position of the inspection stage 22 and the threshold value for specifying the defective portion have been described as an example. However, without being limited to such a configuration, the inspection conditions may include the sensitivity of the image acquisition device, the exposure time, and the like, and may include a lighting device for assisting image acquisition. May include the brightness of the lighting device.

  In the above-described embodiment, the configuration in which the horizontal position of the image inspection stage 22 is determined based on the coordinate information of the defective portion specified in the laser inspection step S1 so that the defective portion is included in the image acquisition range of the camera 21 is described. This has been described as an example. However, without being limited to such a configuration, for example, a portion where the possibility of occurrence of a defect is higher than other portions on the wafer, such as a portion where a jig holding the wafer abuts in a process before the inspection process, may be used. If specified, the portion may be configured to be an image acquisition target regardless of the inspection result by the laser inspection method.

  In the above embodiment, the configuration in which the focus adjustment of the image inspection is performed based on the focus adjustment defect selected in the laser inspection step S1 has been described as an example. However, without being limited to such a configuration, the focus specified for the defect specified in the laser inspection step S1 may be adjusted first based on the defect to be inspected.

  In the above-described embodiment, an example is given in which the camera 21 is controlled based on the focus adjustment defect portion to adjust the focal length of focus, and the subsequent focus adjustment is performed by moving the image inspection stage up and down. It was explained as. However, the focus adjustment may be performed only by controlling the camera 21 without being limited to such a configuration.

  In the above embodiment, the configuration in which the focus adjustment is performed by the line sensor method has been described as an example. However, without being limited to such a configuration, a known autofocus method can be adopted. Further, the focus adjustment may be performed manually.

  In the above embodiment, an example has been described in which, after determining the threshold value based on the inspection result of the reference defect portion, an image inspection is performed on a portion where the defect portion specified by the laser inspection method exists. However, without being limited to such a configuration, an image inspection may be performed on the entire surface of the wafer.

  In the above embodiment, the configuration in which the threshold value of the image inspection is adjusted based on the reference defect portion selected in the laser inspection step S1 has been described as an example. However, without being limited to such a configuration, an image inspection may be performed using a predetermined threshold value, and a defect to be inspected first may be replaced with a defect identified in the laser inspection step S1. The image inspection may be performed by adjusting the threshold based on the threshold value.

  In the above-described embodiment, an example in which the laser inspection step S1 is performed by the laser inspection apparatus 1 and the image inspection step S2 is performed by the image inspection apparatus 2 is described as an example. However, without being limited to such a configuration, the wafer inspection may be performed using only one of the laser inspection method and the image inspection method.

  Regarding other configurations, it should be understood that the embodiments disclosed in the present specification are illustrative in all points, and the scope of the present invention is not limited thereby. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used, for example, in a wafer inspection apparatus used for inspecting a silicon wafer raw material used in semiconductor manufacturing.

D: Wafer inspection device 1: Laser inspection device 11: Light source 12: Detector 121: Scattered light detector 122: Reflected light detector 13: Rotating stage 14: Laser control unit 15: Laser inspection unit 2: Image inspection device 21: Camera 22: Image inspection stage 23: Image acquisition control unit 24: Image inspection unit 3: Transport unit 4: Control unit 5: Display

Claims (5)

A light source for irradiating the wafer with laser light, a detector for detecting the secondary light in which the laser light is scattered or reflected by the wafer, and the wafer based on the intensity of the secondary light detected by the detector. A laser inspection device having a laser inspection unit for inspecting,
An image acquisition device that acquires an observation image of the surface of the wafer, an image acquisition control unit that controls the image acquisition device, and an image inspection unit that inspects the wafer based on the observation image acquired by the image acquisition device, An image inspection apparatus having: and a wafer inspection apparatus comprising:
The laser inspection unit specifies a defective portion of the wafer,
The image inspection apparatus is a wafer inspection apparatus that determines inspection conditions for inspection of the wafer based on information on the defective part specified by the laser inspection unit.   The image acquisition control unit, for at least one selected defect portion selected from the defect portion identified by the laser inspection unit, based on the coordinate information of the selected defect portion identified by the laser inspection unit, based on the observed image 2. The wafer inspection apparatus according to claim 1, wherein a position as an image acquisition target on the wafer is specified so as to include the selected defect portion. 3.   3. The wafer according to claim 2, wherein the image acquisition control unit performs focus adjustment of the image acquisition device so that a difference between a maximum value and a minimum value of luminance in the observation image including the selected defect portion is maximized. 4. Inspection equipment.   The image inspection unit is for identifying a defective portion of the wafer based on a luminance difference that is a difference between a maximum value and a minimum value of luminance in the observation image, and the observation image including the selected defect portion. 4. The wafer inspection apparatus according to claim 2, wherein a threshold value of the luminance difference used by the image inspection unit to identify the defective part is determined based on the luminance difference in the step (c). A laser inspection step of irradiating the wafer with laser light, detecting the secondary light scattered or reflected by the wafer, and inspecting the wafer based on the intensity of the secondary light,
Obtaining an observation image of the surface of the wafer, an image inspection step of inspecting the wafer based on the obtained observation image,
In the laser inspection step, a defective portion of the wafer is specified,
A wafer inspection method for determining inspection conditions for acquiring an observation image for specifying the defective portion in the image inspection step based on information on the defective portion specified in the laser inspection step.

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