JP2014199694A - Disk surface inspection method and its apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect even minute defects that could not be detected in a detection method using a conventional detector, by maintaining high positional accuracy and classification accuracy.SOLUTION: In a method for inspecting a defect on the surface of a disk as a sample, of reflected light and scattered light in a first direction from a disk, mirror reflection light and scattered light from the disk are separated, this separated scattered light is detected by a detector formed by arranging a plurality of light receiving elements in one dimension. The disk is rotated. Also, the disk is moved in a direction perpendicular to the central axis of the rotation so that images in the same area on the disk are detected more than one time using the detector formed by arranging a plurality of light receiving elements in one dimension. Minute defects on the disk are rendered tangible by adding signals obtained by detecting defects on the disk through detecting images in the same area on the disk more than one time. The defects on the disk are categorized using information about the tangible minute detects on the disk and signals that have detected reflected light and scattered light in the second direction.

Description

  The present invention relates to a method and apparatus for optically inspecting defects on a sample surface, and more particularly to a disk surface inspection method and apparatus suitable for inspecting defects on the surface of a glass substrate (disk) for a magnetic disk. .

An aluminum (Al) substrate or a glass substrate is used as the magnetic disk substrate.
As shown in Patent Document 1 and Patent Document 2, defects on the surface of the glass substrate are optically inspected using an optical inspection device. In an apparatus for inspecting the surface of a glass substrate, there is a need to classify detected defects for the purpose of improving process management and contributing to process improvement. The detection optical system of a device for inspecting the surface of a magnetic disk glass substrate (disk) is generally equipped with a plurality of detectors. In addition to the classification of minute defects based on detection signals from these detectors, The defect classification is performed based on the characteristics of the defect distribution shape in the disk surface.

  As an apparatus for inspecting defects on the surface of a conventional disk, for example, in Patent Document 1, a disk, which is a sample to be inspected, is irradiated with a laser, and reflected light and scattered light from the disk surface are received by a plurality of detectors. However, the minute defects are classified according to the light receiving conditions of the respective light receivers. Further, the planar continuity of the detected minute defects is determined to classify the lengths of the defects, linear defects, and block defects.

  Further, Patent Document 2 describes that defects are classified according to the distribution state of defects obtained by inspecting the surface of a semiconductor wafer.

JP 2008-268189 A JP 2012-78140 A

  In an optical inspection apparatus for optically inspecting defects on the surface of a conventional disk, as described in Patent Documents 1 and 2, light is irradiated onto a substrate that is rotated at high speed, and reflected light from the substrate. Detecting a defect when a signal greater than the threshold value is detected by comparing the detection signal level with a preset threshold value using multiple detectors arranged in different elevation angles. Judgment.

  As the recording density of the magnetic disk increases, the size of defects to be detected on the disk surface also becomes smaller. Patent Document 1 describes that finer defects are detected by a highly sensitive sensor such as a photomultiplier tube from scattered light generated from a disk surface irradiated with a laser.

  However, even if the scattered light from the disk is detected by a highly sensitive detector such as a photomultiplier tube, the rotation speed of the disk becomes faster and more fine defects are detected. The amount of photons incident on the photomultiplier tube decreases, and the level of the signal output from the photomultiplier tube decreases. As a result, the S / N ratio of the detection signal is lowered, and the lower limit value of the size of the defect that can be detected is limited.

  Japanese Patent Application Laid-Open No. H10-228688 describes increasing the resolution of the position of a detected defect using a CCD sensor having a plurality of detection elements. However, there is no description about improving the defect detection sensitivity of the CCD sensor so that finer defects can be detected.

  Patent Document 2 describes processing of detection signals from a plurality of detectors to detect minute defects on the substrate surface, but the amount of photons incident on the detector is reduced. It does not describe that a minute defect can be detected.

  The present invention solves the above-mentioned problems of the prior art, and the ratio of the detection signal of fine defects and the noise, that is, the S / N ratio, which is the limit of detection in the detection method using the conventional detector. The surface of the disk that can improve the position accuracy and classification accuracy even for minute defects that have been the limit of detection in the detection method using a conventional detector. An inspection method and an inspection apparatus are provided.

  In order to solve the above-described problems, in the present invention, a disk surface inspection apparatus includes a stage unit that can be rotated by placing a disk as a sample and can move in a direction perpendicular to the central axis of rotation, and the stage. An illuminating means for irradiating light on a disk placed on the means; a first detecting means for detecting light reflected and scattered in a first direction from the disk irradiated with light by the illuminating means; and an illuminating means. Second detection means for detecting light reflected / scattered in a second direction from the disk irradiated with light, and detecting light reflected / scattered in the first direction from the disk by the first detection means; A defect on the disk is detected by processing the obtained first detection signal and the second detection signal obtained by detecting the light reflected and scattered from the disk in the second direction by the second detection means. Processing means, stage means and illumination means And a control means for controlling the first detection means, the second detection means, and the processing means, wherein the first detection means is the light reflected / scattered from the disk in the first direction from the disk. Specularly reflected light detection unit that detects and detects specularly reflected light separately from scattered light, and the remaining scattered light from which specularly reflected light is separated is detected by a detector formed by arranging a plurality of light receiving elements in one dimension. And the control means rotates the disk with the stage means while moving the disk in a direction perpendicular to the central axis of rotation, and the image at the same position on the disk is scattered light of the first detection means. The stage unit is controlled so that the detection unit detects a plurality of times, and the processing unit adds signals obtained by detecting the image of the same portion of the disk a plurality of times by the scattered light detection unit of the first detection unit. A small defect on the disk was revealed, and this was revealed It was to classify defects on the specimen by using the detected signal with a minute defect information and the second detection means on the disk.

  Further, in order to solve the above-described problems, in the present invention, the disk, which is a sample, is rotated, and the disk is irradiated with light while being moved in a direction perpendicular to the central axis of rotation. A signal that detects light reflected / scattered in the first direction, detects light reflected / scattered in the second direction from the disk irradiated with the light, and detects light reflected / scattered in the first direction; In a disk surface inspection method for detecting a defect on a sample by processing a signal obtained by detecting light reflected / scattered in a second direction, positive light from the disk out of light reflected / scattered in the first direction from the disk. The reflected light and the scattered light are separated, and the separated scattered light is detected by a detector formed by arranging a plurality of light receiving elements in a one-dimensional manner, and the disk is rotated and in a direction perpendicular to the central axis of rotation. It is not possible to move The image of the same part of the disc is detected by moving the image of the same part of the disc so that it can be detected multiple times by a detector formed by arranging a plurality of light receiving elements in one dimension. Signals obtained by detecting multiple times are added to reveal minute defects on the disc, and information on the minute defects on the revealed disc and light reflected and scattered in the second direction are detected. Signals are used to classify defects on the disc.

  According to the present invention, the detection method using the conventional detector can improve the S / N ratio of the detection signal of the minute defect which has become the limit of detection, and the conventional detector is used. It has become possible to detect a minute defect that has been the limit of detection in the detection method while maintaining high position accuracy and classification accuracy.

1 is a block diagram showing a schematic configuration of a disk surface inspection apparatus in an embodiment of the present invention. It is a top view of the sample which shows the r direction and (theta) direction of the disk surface in the Example of this invention. It is a top view of the disk which shows the shape of the irradiation area | region of the illumination light of the disk surface in the Example of this invention. It is a front view of the one-dimensional CCD sensor which shows the light-receiving surface of the light receiving element of the one-dimensional CCD sensor which comprises the high angle detector in an Example in this invention. It is a front view of the one-dimensional CCD sensor showing a time change in a state in which an image of the illumination area of the illumination light on the disk surface is formed on the light receiving element of the one-dimensional CCD sensor of the high angle detector in the embodiment of the present invention. It is a graph which shows the result of having added them together with the time change of the output of each light receiving element of the one-dimensional CCD sensor of the high angle detector in an Example to this invention. The front view of a one-dimensional CCD sensor showing a state in which a defect image is projected linearly on the light-receiving surface of the light-receiving element of the one-dimensional CCD sensor constituting the high-angle detector in the embodiment of the present invention, and the linear defect It is sectional drawing. It is a flowchart which shows the flow of the process which performs the detection and classification of the defect in an Example in this invention. It is a front view of the display screen which shows the state which output on the screen the result of the defect inspection in an Example to this invention.

The present invention repeatedly detects scattered light from the surface of a disk, which is a glass substrate for a magnetic disk,
The S / N ratio is improved by adding the detection signals of scattered light from repeatedly detected defects,
The detection sensitivity of fine defects is improved as compared with the case where defects are detected by a conventional detector.
Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A shows a schematic configuration of a disk surface inspection apparatus 1000 according to this embodiment.
The disk 1 to be inspected is a glass substrate (disk) for a magnetic disk, and the surface is not coated with a thin film or the like, and the glass material is exposed. The disk surface inspection apparatus 1000 includes an illuminating unit 100 that irradiates the disk 1 with illumination light, and a high angle detection optical system 110 that collects and detects light reflected and scattered in a high angle direction from the disk 1 irradiated with the illumination light. The medium angle detection optical system 120 that collects and detects light scattered in the medium angle direction from the disk 1 and the low angle detection optical system 130 that collects and detects light scattered in the low angle direction from the disk 1. A processing device 160 for processing a signal detected by the detection optical system, an input / output means 170 for inputting processing conditions of the processing device 160 and outputting a processing result, an overall control unit 180 for controlling the entire device, and a sample (disc 1) Is equipped with stage means 190 that moves in one direction while rotating.

The illuminating unit 100 includes a laser light source that outputs a laser having a desired wavelength, and irradiates the surface of the disk 1 with a laser from an oblique direction.
The high angle detection optical system 110 includes reflected / scattered light including specularly reflected light traveling in the high angle direction (high elevation angle direction) among the reflected / scattered light generated from the surface of the disk 1 irradiated with laser by the illumination unit 100. An objective lens 111 that collects reflected / scattered light including specularly reflected light that has traveled in a high angle direction from the surface of the disk 1, and from the disk 1 out of the light collected by the objective lens 111. A mirror 112 that reflects the regular reflection light, a pinhole plate 113 that has a pinhole that allows the regular reflection light from the disk 1 reflected by the mirror 112 to pass therethrough and shields stray light other than the regular reflection light, and this pinhole plate A specular reflection light detector 114 configured with a photoelectric converter (photosensor) that detects specular reflection light that has passed through 113, and is not reflected by the mirror 112 out of the light collected by the objective lens 111. A converging lens 115 for converging the light (scattered light from the disk 1), a pinhole located at the converging point of the converging lens 115 for passing the converged light, and blocking the unconverged light A plate 116 and a high angle detector 117 composed of a one-dimensional CCD sensor for detecting light passing through the pinhole plate 116 are provided.

The medium angle detection optical system 120 includes an objective lens 121 that collects scattered light traveling in the medium angle direction out of light generated by reflection and scattering of the laser emitted from the illumination unit 100 on the surface of the disk 1.
A converging lens 122 for converging the light collected by the objective lens 121, a pinhole plate that is located at the converging point of the converging lens 122 and has a pinhole that allows the converged light to pass therethrough and shields the light that has not been converged 123, a medium angle detector 124 composed of a photomultiplier tube (photomultiplier: photomultiplier) for detecting light passing through the pinhole plate 123 is provided.

  The low-angle detection optical system 130 includes an objective lens 131 that collects scattered light traveling in the low-angle direction out of light generated by reflection and scattering of the laser emitted from the illumination unit 100 on the surface of the disk 1, and an objective lens A converging lens 132 for converging the light collected at 131, a pinhole plate 133 for blocking the unconverged light having a pinhole for passing the converging light located at the converging point of the converging lens 132, A low-angle detector 134 composed of a photomultiplier tube (photomultiplier: photomultiplier) that detects light passing through the pinhole plate 133 is provided.

  Signals output from the detectors 114, 117, 124, and 134 are amplified by A / D converters 141, 142, 143, and 144, A / D converted, and input to the processing device 160.

  The processing device 160 includes a detection signal adding unit 161 that superimposes a plurality of signals output from the detector 117 A / D converted by the A / D converter 141 to create a composite signal, and the detection signal adding unit 161 A defect candidate extraction unit 162 that detects a defect candidate by receiving the added signal and signals output from the respective detectors 114, 124, and 134 A / D converted by the A / D converters 142, 143, and 144; The connection / continuity of the defect candidates detected by receiving the signal from the candidate extraction unit 162 and the position information of the disk 1 from the stage means 190 (rotation direction: θ and radial direction: r shown in FIG. 1B) is determined. Defect candidate continuity determining unit 163, defect feature amount calculating unit 164 for calculating feature amounts (length, width, area in r direction and / or θ direction) of defect candidates determined for connection / continuity, defect feature amount Calculation Defect classification unit 165 for classifying the defect in response to a signal from 164, and a substrate acceptability judging section 166 for judging the quality of the substrate receives the density information of the classified defect.

  The processing device 160 has a display screen 171 and is connected to input / output means 170 for inputting inspection conditions and outputting inspection results. The processing device 160 and the input / output means 170 are connected to the overall control unit 180. The overall control unit 180 places the disk 1 and rotates the disk 1, and also includes a stage unit 190 including a stage that can move in at least one axial direction within the plane in which the disk 1 rotates, the illumination unit 100, and the processing The unit 160 and the input / output unit 170 are controlled.

  With the above configuration, the stage controller 190 is rotated with the disk 1 placed thereon under the control of the overall control unit 180, and the speed is constant in one direction (radial direction of the disk 1) perpendicular to the center of rotation. To start moving.

  In this state, a laser beam is irradiated from the illuminating unit 100 onto the surface of the disk 1 rotating on the stage unit 190, and the specularly reflected light out of the light reflected and scattered by the surface of the disk 1 and directed in the direction 110 is normal. The reflected light detector 114 and the scattered light around the specularly reflected light are detected by the high angle detector 117. Also, scattered light directed from the surface of the disk 1 toward the medium angle detection optical system 120 is detected by the medium angle detector 124, and scattered light directed toward the low angle detection optical system 130 is detected by the low angle detector 134. Detected.

  The signals output from the detectors 114, 117, 124 and 134 are input to the A / D converters 141 to 144, amplified, converted into digital signals, and input to the processing device 160.

  By performing such inspection from the outer peripheral portion to the inner peripheral portion of the disc 1 by moving it straightly while rotating the disc 1, the entire front side of the disc 1 can be inspected. Further, both sides of the sample can be inspected by inverting the disk 1 using a substrate inverting mechanism (not shown) so that the uninspected back surface is up and performing the same inspection as the front surface. .

  Further, by detecting the level of the regular reflection light detection signal output from the regular reflection light detector 114, the state of the reflectance of the illumination light on the surface of the disk 1 is checked, and the degree of contamination on the surface of the disk 1 It is possible to determine whether or not different types of disks are mixed.

  In this example, pinhole plates 113, 116, 123, 133 for blocking stray light are used for the high angle detection optical system 110, the medium angle detection optical system 120, and the low angle detection optical system 130, respectively. When a polarizing plate is inserted in the optical path of a laser emitted from the light source 100 to illuminate the disk 1 with polarized light, a polarizing filter may be used instead of the pinhole plates 113, 116, 123, 133. When a single wavelength laser is used as the laser emitted from the illumination light source 100, a wavelength selection filter may be used instead of the pinhole plates 113, 116, 123, 133. Further, it may be configured to use a polarizing filter and a wavelength selection filter in combination so as to pass light of a specific polarization component having a specific wavelength.

  In the configuration described above, in this embodiment, the illumination unit 100 irradiates a spot-like beam from a direction (oblique direction) inclined with respect to the normal direction of the surface of the disk 1 as shown in FIG. 2A. Illumination light is applied to the elongated linear region 11 on the surface of the disk 1.

  On the other hand, as the high angle detector 117 of the high angle detection optical system 110, in this embodiment, it is constituted by a one-dimensional CCD sensor in which a plurality of detection elements are arranged in a line, and the illumination light on the surface of the disk 1 is irradiated. An optical image of the long and narrow linear region 11 is projected. As shown in FIG. 2B, the light receiving surface 1171 of the one-dimensional CCD sensor that is the high angle detector 117 is composed of a plurality (n pieces) of light receiving elements pn (in the case of FIG. 2B, n is 12). ing.

  Here, when the disk 1 is continuously moved in the r direction while being rotated by the stage means 190, the amount of movement is projected onto the one-dimensional CCD sensor for each rotation of the disk 1, as shown in FIG. 2C. The image of the disk 1 (in the case of FIG. 2C, the image 12 of the illumination light irradiation area 11 on the surface of the disk 1) is set to move by 4 pixels on the light receiving surface 1171 of the one-dimensional CCD sensor.

  At this time, if a minute defect exists in the illumination light irradiation area 11 on the surface of the disk 1, the image 13 of the minute defect is on the pixel P11 on the light receiving surface 1171 of the one-dimensional CCD sensor when the disk is rotated r1. Is projected onto the p7 pixel when the disk is rotated (r1 + 1) and projected onto the p3 pixel when the disk is rotated (r1 + 2). That is, the minute defect image 13 is projected and detected a plurality of times (three times in this embodiment) on the light receiving surface 1171 of the one-dimensional CCD sensor.

  The output signal from the one-dimensional CCD sensor 1171 that has detected the minute defect image 13 is the output signal level of each sensor during r1 rotation as shown in FIG. 2D (a), as shown in (b). The output signal level at the time of (r1 + 1) rotation, and the output signal level at the time of (r1 + 2) rotation as shown in (c). Like these detection signals, the output signal from the light receiving element that has detected the image of scattered light from the normal part varies due to noise, so the S / N ratio is deteriorated, and the scattered light from a minute defect is reduced. It is difficult to discriminate between the output signals 1311, 1312, 1313 from the light receiving element that detected the image and the output signals from the light receiving element that detected the image of the scattered light from the normal part.

  Therefore, in this embodiment, the moving speed of the stage means 190 in the disk radial direction (r direction) is controlled so that the same defect image is detected on the one-dimensional CCD sensor 1171 a plurality of times. Then, detection of each light receiving element of the one-dimensional CCD sensor 1171 for each rotation of the disk 1 output from the high angle detector 117 using information on the amount of movement of the stage means 190 in the disk radial direction for each rotation of the disk. The signals (images) were shifted by a predetermined pitch (in this example, 4 pixels) and added together. As a result, since the noise signal is generated randomly, it does not increase even when the signal is added, whereas the signal that detects the defect image becomes large when added, as shown in FIG. 2D (d). The S / N ratio is improved, and an enhanced defect signal 1310 can be obtained.

  As a result, a minute defect that cannot be detected because it is buried in a noise signal in the conventional method becomes obvious and can be detected by comparing with a preset threshold value TH.

  Here, a minute defect detected from the detection signal of one or two light receiving elements among the light receiving surfaces formed by the plurality of light receiving elements of the one-dimensional CCD sensor 1171 of the high angle detector 117 is projected. In the case of a minute defect (foreign matter), scattered light is also detected by the medium angle detector 124 and the low angle detector 134. On the other hand, scattered light from minute dents or so-called bright spots is not detected by the medium angle detector 124 and the low angle detector 134.

  Therefore, it is possible to identify a minute foreign object and a minute dent or bright spot using the detection signal from the high angle detector 117 and the detection signals from the medium angle detector 124 and the low angle detector 134. Become.

  In the above description, the stage means 190 is continuously moved while the disk 1 is rotated to inspect the disk surface in a spiral shape. However, the stage means 190 is rotated at a predetermined pitch while rotating the disk (see FIG. In the case of the present embodiment, the inspection may be performed by a seek operation in which the image on the disk surface projected on the light receiving surface 1171 of the one-dimensional CCD sensor is moved by an amount of four pixels.

  Further, as shown in FIG. 3 (a), when there are fine linear scratches 14 on the surface of the disk 1, an image of the linear fine scratches is a plurality of as shown in (b). It is detected as a defect 15 over the pixel. Even in such a case, by adding the images detected a plurality of times while shifting by a predetermined pitch, it becomes possible to reveal and detect a detection signal of a linear fine defect. Of the scattered light from the fine linear scratch 14 on the surface of the disk 1, the amount of light incident on the low angle detection optical system 130 is small, and the level of the signal output from the detector 134 is low.

  On the other hand, the linear bulge formed on the light receiving element of the one-dimensional CCD sensor 1171 also when the surface of the disk 1 has a linear bulge (wrinkle) defect 16 as shown in FIG. The optical image is detected as a defect over a plurality of pixels in the same manner as shown in FIG. At this time, a relatively large amount of scattered light from the linear bulge-like defect 16 is also incident on the low-angle detection optical system 130, and the detector 134 has a detection level sufficient to detect the defect. A signal is output.

  That is, when a defect signal over a plurality of pixels is output from the one-dimensional CCD sensor 1171, is the signal detected by detecting a linear flaw by comparing the output signals from the low angle detection optical system 130? Alternatively, it is possible to determine whether the signal is a signal in which a linear bulge is detected.

Next, the processing procedure input to the processing device 160 will be described with reference to FIG.
First, signals output from the A / D converters 141 to 144 are input to the processing device 160 (S401).

  Next, in the detection signal adding unit 161, the detection signal of the detector 117 input from the A / D converter 141 is shifted by 4 pixels as described with reference to FIG. Create (S402). Next, in the defect candidate extraction unit 162, the level of the signal input from the detection signal addition unit 161 and the A / D converters 142 to 144 is compared with a preset threshold, and the level exceeding this threshold Is extracted as a defect candidate in association with position information (rotation angle information of the stage 190 and substrate radial direction position information) of defect candidates obtained from a detection system (not shown) of the stage means 190 (S403). ).

  Next, the defect candidate continuity determination unit 163 determines the connection / continuity of each defect candidate using the position information of the defect candidate on the disk 1 extracted by the defect candidate extraction unit 162 (S404). The defect candidates determined to be connected / continuous in S404 are processed as one defect thereafter.

  A defect candidate feature amount calculation unit 164 calculates defect feature amounts such as defect dimensions (r direction length, θ direction length, defect width), area, and the like for the defect candidates for which connection / continuity is determined. (S405). At this time, for the defect candidates determined to be connected / continuous by the defect candidate continuity determination unit 163, the feature amount is calculated as one defect.

  Finally, the defect classification unit 165 checks whether or not the defect whose feature value is calculated is a continuous defect (S406). If it is determined that the defect is a continuous defect, it is checked whether it is a linear defect (S407). If the continuous defect has no spread in the plane, the low-angle detection optical system 130 When there is no detection signal (S408), if there is no detection signal from the low angle detection optical system 130, it is determined as a linear defect (S409), and there is a detection signal from the low angle detection optical system 130 Is determined to be a defect due to swelling on the substrate (S410). On the other hand, when it is determined that a continuous defect has an in-plane spread (NO in S407), it is determined as a planar defect (S411).

  On the other hand, if it is determined in S406 that the defect is not a continuous defect, it is checked whether the defect is also detected by the medium angle detector 124 and the low angle detector 134 (S412). When it is also detected by the detector 134 (YES), it is determined as a foreign object defect (S413), and when it is not detected by the medium angle detector 124 and the low angle detector 134 (NO), a bright spot (a minute defect). ) Is determined (S414).

  The defect information thus classified and the information on the result of determining the material of the substrate are sent to the substrate quality determining unit 166 to determine the quality of the substrate (S415), and the result is output to the input / output means 170. (S416).

  The input / output unit 170 receives the determination result of the substrate quality determination unit 166, and maps the defect distribution 1711 on the front surface of the disk 1 and the defect distribution 1712 on the back surface of the disk 1 on the display screen 171 as shown in FIG. 5A. In addition to the display, the type of defect is displayed 1713, and the result 1714 of the quality determination between the front surface and the back surface of the substrate is displayed together with the substrate lot number and the substrate number 1715.

  The defect map may be displayed on the display screen 171 by switching only one of the defect distribution 1711 on the front surface of the disk 1 or the defect distribution 1712 on the back surface.

  According to the present embodiment, a signal obtained by detecting scattered light from a minute defect that is buried in the detection signal can be revealed, and by combining with a detection signal from another detection system, Fine foreign matter defects and dents, linear defects, and linear bulge defects can now be reliably classified.

  As mentioned above, although the invention made by the present inventor has been specifically described based on the embodiments, it is needless to say that the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof. Yes.

  DESCRIPTION OF SYMBOLS 1 ... Disc 100 ... Illuminating means 110 ... High angle detection optical system 114 ... Regular reflection light detector 117 ... High angle detector 120 ... Medium angle detection optical system 130 ... Low angle detection optical system 141-144 ... A / D converter DESCRIPTION OF SYMBOLS 160 ... Processing apparatus 161 ... Detection signal addition part 162 ... Defect candidate extraction part 163 ... Defect candidate continuity determination part 164 ... Defect feature-value calculation part 165 ... Defect classification part 166 ... Substrate quality determination part 170 ... Input / output part 180 ... Whole Control unit 190... Stage means.

Claims (10)

Stage means which can be rotated by placing a disk as a sample and movable in a direction perpendicular to the central axis of rotation;
Illuminating means for irradiating light onto the disk mounted on the stage means;
First detection means for detecting light reflected and scattered in a first direction from the disk irradiated with light by the illumination means;
Second detection means for detecting light reflected and scattered in a second direction from the disk irradiated with light by the illumination means;
A first detection signal obtained by detecting light reflected and scattered from the disk in the first direction by the first detection means; and a second detection means from the disk in the second direction. Processing means for detecting a defect on the disk by processing a second detection signal obtained by detecting the reflected / scattered light;
A disk surface inspection apparatus comprising a control means for controlling the stage means, the illumination means, the first detection means, the second detection means, and the processing means,
The first detecting means includes a specularly reflected light detecting unit that separates and detects specularly reflected light from the disc out of light reflected and scattered in the first direction from the disc, and the specularly reflected light. A scattered light detector that detects the remaining scattered light separated by a detector formed by arranging a plurality of light receiving elements in a one-dimensional manner,
When the control means moves the disk in the direction perpendicular to the center axis of rotation while rotating the disk by the stage means, the image of the same portion of the disk is detected by the scattered light detection unit of the first detection means. Controlling the stage means to be detected multiple times,
The processing means adds a signal obtained by detecting an image of the same portion of the disk a plurality of times by the scattered light detection unit of the first detection means to reveal minute defects on the disk, A disk surface inspection apparatus, wherein the defects on the sample are classified by using the information on the minute defects on the disk that have been revealed and the signal detected by the second detection means.   2. The disk surface inspection apparatus according to claim 1, wherein the detector formed by one-dimensionally arranging a plurality of light receiving elements of the first detection means is a one-dimensional CCD sensor. Disk surface inspection device.   2. The disk surface inspection apparatus according to claim 1, wherein the processing means uses the information on minute defects on the disk that have been revealed and a signal detected by the second detection means. A disk surface inspection apparatus characterized in that the above minute defects are classified into a plurality of defects including foreign matter defects and linear flaws.   2. The disk surface inspection apparatus according to claim 1, wherein the processing means uses a signal detected by a specular reflection light detection unit of the first detection means to detect contamination on the disk surface or the material of the disk. Disc surface inspection apparatus characterized by determining whether or not is genuine.   4. The disk surface inspection apparatus according to claim 1, further comprising display means for displaying a processing result of the processing means on a screen, together with a number for identifying the disk on the screen of the display means. A disk surface inspection apparatus for displaying a distribution of defects on the disk for each type of defect. While rotating the disk which is the sample and moving it in a direction perpendicular to the central axis of rotation, the sample is irradiated with light,
Detecting light reflected / scattered in a first direction from the disk irradiated with the light;
Detecting light reflected and scattered in a second direction from the disk irradiated with the light;
A disk surface inspection method for detecting a defect on the disk by processing a signal that detects light reflected / scattered in the first direction and a signal that detects light reflected / scattered in the second direction. There,
Of the light reflected and scattered in the first direction from the disk, the specularly reflected light and scattered light from the disk are separated, and the separated scattered light is formed by arranging a plurality of light receiving elements in one dimension. A detector in which an image of the same portion of the disk is formed by arranging the plurality of light receiving elements in a one-dimensional manner to detect with a detector and rotate the disk and move in a direction perpendicular to the central axis of rotation. In order to detect a defect on the disk, a small defect on the disk is revealed by adding a signal obtained by detecting an image of the same portion of the disk multiple times. And classifying the defects on the sample by using the information on the minute defects on the disc that have been visualized and the signal that has detected the light reflected and scattered in the second direction. Disc surface inspection method.   The disk surface inspection method according to claim 6, wherein specularly reflected light and scattered light from the disk out of light reflected and scattered in the first direction from the disk are separated, and the separated scattered light is obtained. A disk surface inspection method characterized by detecting with a one-dimensional CCD sensor.   7. The disk surface inspection method according to claim 6, wherein a signal obtained by detecting light reflected / scattered in the first direction and a signal obtained by detecting light reflected / scattered in the second direction are processed. Detecting a defect on the disc is performed by using the information on the minute defect on the disc that has been revealed and a signal that detects light reflected / scattered in the second direction. A disk surface inspection method characterized in that a simple defect is classified into a plurality of defects including a foreign matter defect and a linear scratch.   7. The disk surface inspection method according to claim 6, wherein a signal that detects light reflected / scattered in the first direction and a signal that detects light reflected / scattered in the second direction are processed. Detecting a defect on the disk using a signal obtained by detecting specularly reflected light obtained by separating specularly reflected light and scattered light from the disk out of the light reflected and scattered in the first direction, A disc surface inspection method characterized by determining whether the disc surface is dirty or whether the disc material is regular.   9. The disk surface inspection method according to claim 6, wherein a signal that detects light reflected and scattered in the first direction and a signal that detects light reflected and scattered in the second direction are processed. And the result of detecting the defect on the disk is displayed on the screen of the display means together with a number for identifying the disk and the distribution of the defect on the disk for each type of defect. Inspection method.

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