JP5183147B2 - Disc-shaped substrate inspection equipment - Google Patents

Description

  The present invention relates to a disk-shaped substrate inspection apparatus for photographing and inspecting an outer peripheral portion of a disk-shaped substrate such as a semiconductor wafer.

  A disk-shaped semiconductor wafer (disk-shaped substrate) has a structure as shown in FIGS. 21 (a) and 21 (b), for example. FIG. 21A is a perspective view of a semiconductor wafer, and FIG. 21B is an enlarged cross-sectional view taken along the line AA of FIG. As shown in FIGS. 21A and 21B, the outer peripheral portion 10E of the semiconductor wafer 10 has an upper outer peripheral bevel surface 12U inclined from the upper surface 11a edge toward the lower surface 11b, and conversely, the lower surface 11b edge. A lower outer peripheral bevel surface 12L inclined toward the upper surface 11a and an outer peripheral end surface 12A joined to the upper outer peripheral bevel surface 12U and the lower outer peripheral bevel surface 12L are formed. In addition, a notch 13 that represents a reference position in the circumferential direction Ds is formed in the outer peripheral portion 10E.

In the course of the manufacturing process of the semiconductor wafer 10, various film layers such as a resist film, an insulating film, and a conductive film are formed on the surface (see, for example, Patent Document 1). These film layers are necessary for the manufacturing process of the semiconductor wafer 10, are necessary for exhibiting the designed functions, and have various purposes, and there are regions to be formed according to the purpose. It has been decided. A film layer to be formed on the upper surface 11a so as not to reach the boundary with the upper outer peripheral bevel surface 12U, a film layer to be formed to reach the upper outer peripheral bevel surface 12U from the upper surface 11a, and an upper outer peripheral bevel surface from the upper surface 11a A film layer to be formed so as to reach the outer peripheral end surface 12A past 12U, and further to reach the lower outer peripheral bevel surface 12L from the upper surface 11a past the upper outer peripheral bevel surface 12U and the outer peripheral end surface 12A. There are film layers and the like.
JP 2007-142181 A

  In such a situation, it is necessary to inspect the state of the film layer formed on the surface of the wafer 10 (for example, peeling, position of edge line, etc.), but conventionally, the film layer is formed over a plurality of continuous surfaces. In addition, there was no inspection apparatus capable of accurately evaluating the state of the film layer on the wafer 10. Further, the conventional inspection apparatus cannot accurately evaluate the state of the wafer 10 in which scratches are formed over a plurality of continuous surfaces or foreign substances are adhered over a plurality of continuous surfaces.

  This invention is made in view of such a situation, and provides the inspection apparatus of the disk shaped board | substrate which can test | inspect (evaluate) the state of the several continuous surface of a disk shaped board | substrate more accurately. is there.

The disk-shaped substrate inspection apparatus according to the present invention includes a plurality of surfaces that are continuous in a direction crossing a circumferential direction in an outer peripheral portion of the disk-shaped substrate, and each of the plurality of surfaces includes the disk-shaped substrate. An imaging unit that sequentially captures images in the circumferential direction and outputs image signals;
An image processing unit that processes image signals sequentially output from the photographing unit;
The image processing unit
Based on the image signal, image data generating means for generating photographic image data representing a photographic image corresponding to each photographing visual field range including each of the plurality of surfaces extending corresponding to the circumferential direction of the disc-shaped substrate;
From photographed image data representing a photographed image corresponding to each photographing field range including each of the plurality of surfaces, a plurality of surface image portions corresponding to the plurality of surfaces are joined so as to match their corresponding boundary lines. Image synthesizing means for generating synthesized image data representing the synthesized image,
It possesses an output control means for displaying on the display unit of the composite image based on the composite image data,
The image synthesizing unit includes a boundary line between a surface image portion corresponding to the surface on a captured image corresponding to each photographing field range including each of the plurality of surfaces and an outer image portion on one surface side adjacent to the surface. The vertical position of each pixel point at the corresponding position in the circumferential direction is represented on the basis of the vertical position representing the position in the direction across the circumferential direction at each position in the circumferential direction. Correction means for correcting captured image data representing a captured image;
On the photographic image corresponding to the photographic field range including the predetermined plane of the plurality of surfaces, from the corrected photographic image data representing the photographic field range corresponding to each photographic field range including each of the plurality of surfaces. The combination in which the boundary line is a reference boundary line, and the vertical position of each pixel point at the corresponding position in the circumferential direction is determined with reference to the vertical position at each position in the circumferential direction of the reference boundary line The image forming apparatus includes a composite image data generating unit that generates composite image data representing an image .

  According to the present invention, from photographed image data representing photographed images corresponding to each photographing field of view including each of a plurality of continuous surfaces, a plurality of surface image portions corresponding to the plurality of surfaces are represented by their corresponding boundary lines. It is possible to comprehensively grasp the state of a plurality of continuous surfaces of the disk-shaped substrate from the composite image displayed on the display unit based on the image composite data representing the composite image joined so as to match As a result, the state of a plurality of continuous surfaces of the disk-shaped substrate can be inspected (evaluated) with higher accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The disk-shaped substrate inspection apparatus according to the embodiment of the present invention is realized by, for example, a semiconductor wafer edge inspection apparatus. The imaging system of this semiconductor wafer edge inspection apparatus is configured as shown in FIG. 1, for example.

  In FIG. 1, a stage 100 is held on a rotating shaft 110 a of a rotary drive motor 110 and is rotated in a certain direction. On the stage 100, a semiconductor wafer (hereinafter simply referred to as a wafer) 10 serving as a disk-shaped substrate is set in a horizontal state. The stage 100 is provided with an alignment mechanism (not shown), and on the stage 100 of the wafer 10 so that the center of the wafer 10 matches the rotation center of the stage 100 (the axis of the rotating shaft 110a) as much as possible. The position of is adjusted.

  Five cameras of a first camera unit 130a, a second camera unit 130b, a third camera unit 130c, a fourth camera unit 130d, and a fifth camera unit 130e so as to face the outer peripheral portion of the wafer 10 set on the stage 100. A unit (for example, a camera incorporating a CCD line sensor as an image sensor) is disposed. The five camera units 130a to 130e constitute an imaging unit in the edge inspection apparatus.

  In the outer peripheral portion 10E of the wafer 10, as described with reference to FIG. 21, the upper outer peripheral bevel surface 12U continuing from the upper surface 11a, the lower outer peripheral bevel surface 12L continuing from the outer peripheral end surface 12A and the lower surface 11b crosses the circumferential direction Ds. It is formed to be continuous. A specific arrangement relationship of the five camera units 130a, 130b, 130c, 130d, and 130e with respect to the wafer 10 is as shown in FIG.

  In FIG. 2, the first camera unit 130a is arranged so as to face the upper outer peripheral bevel surface 12U, and its photographing field range F1 includes the upper outer peripheral bevel surface 12U, slightly on the upper surface 11a side and the outer peripheral end surface 12A side. It has spread. The second camera unit 130b is disposed so as to face the outer peripheral end surface 12A, and the imaging field range F2 includes the outer peripheral end surface 12A and slightly extends to the upper outer peripheral bevel surface 12U side and the lower outer peripheral bevel surface 12L side. . The third camera unit 130c is arranged so as to face the lower outer peripheral bevel surface 12L, and the photographing field range F3 includes the lower outer peripheral bevel surface 12L and slightly extends to the outer peripheral end surface 12A side and the lower surface 11b side. The fourth camera unit 130d is arranged so as to face a region adjacent to the upper and outer peripheral bevel surfaces 12U of the upper surface 11a (hereinafter referred to as an upper surface outer peripheral portion as appropriate), and its photographing field range F4 includes the upper surface outer peripheral portion. It slightly extends to the upper outer peripheral bevel surface 12U side. Further, the fifth camera unit 130e is arranged so as to face a region adjacent to the lower outer peripheral bevel surface 12L of the lower surface 11b (hereinafter, referred to as a lower surface outer peripheral portion as appropriate), and its photographing field range F5 includes the lower surface outer peripheral portion. Including the outer peripheral bevel surface 12L slightly.

  Although the illumination system is not shown in FIG. 2, actually, the reflected light from the surface directly facing each of the five camera units 130a, 130b, 130c, 130d, and 130e is effectively incident. As described above, the illumination light is irradiated to the respective surfaces 11a, 12U, 12A, 12L, and 11b in the outer peripheral portion 10E of the wafer 10. Further, the depth of field of each camera unit 130a, 130b, 130c, 130d, 130e is set so that, for example, the surface directly facing the camera unit is clearly captured.

  The CCD line sensor used as the image sensor of each of the camera units 130a, 130b, 130c, 130d, and 130e extends in a direction that intersects the circumferential direction of the wafer 10 (Ds: a direction perpendicular to the paper surface of FIG. 2) at a substantially right angle. Are arranged as follows.

  In the edge inspection apparatus for the wafer 10 having the photographing system as described above, the first camera unit 130a is on the upper and outer peripheral bevel surface 12U and the second camera unit 130b is in the process of rotating the wafer 10 as the stage 100 rotates. The outer peripheral end surface 12A is sequentially scanned in the circumferential direction (Ds) by the third camera unit 130c in the lower outer circumferential bevel surface 12L, the fourth camera unit 130d in the upper outer circumferential portion, and the fifth camera unit 130e in the lower circumferential portion (Ds). Scan). Accordingly, the first camera unit 130a captures the upper and outer peripheral bevel surfaces 12U in the circumferential direction Ds and sequentially outputs image signals in units of pixels, and the second camera unit 130b captures the outer peripheral end surface 12A in the circumferential direction Ds and pixels. Unit image signals are sequentially output, the third camera unit 130c shoots the lower outer peripheral bevel surface 12U in the circumferential direction Ds and sequentially outputs pixel unit image signals, and the fourth camera unit 130d circumferentially moves the upper surface outer peripheral portion. The fifth camera unit 130e captures the lower surface outer peripheral portion in the circumferential direction Ds and sequentially outputs the pixel unit image signal.

  The processing system of the edge inspection apparatus described above is configured as shown in FIG.

  In FIG. 3, the first camera unit 130a to the fifth camera unit 130e are connected to a processing unit 200 (image processing unit) configured by a computer. The processing unit 200 performs drive control of the rotation drive motor 110 so that the stage 100 on which the semiconductor wafer 10 is set in the horizontal state by the alignment mechanism is rotated at a predetermined speed, and the first camera unit 130a to the fifth camera unit. The image signals sequentially output from each of 130e are processed. The processing unit 200 is connected to an operation unit 210 and a display unit 220, executes various processes based on signals from the operation unit 210 operated by an operator, and generates image data generated from the image signal. The display unit 220 displays information representing the inspection image obtained by processing the image data and the image data.

  Incidentally, for example, a film layer 20 (an insulating film layer, a conductive film layer, a resist film layer, etc.) is formed on the surface of the wafer 10 to be inspected by the edge inspection apparatus described above, as shown in FIG. 4 shows a cross section at a certain position in the circumferential direction Ds of the wafer 10, specifically, at a rotation angle position θi (a circumferential position) from a reference position (for example, the notch 13 shown in FIG. 21). Show. Further, in FIG. 4, the thickness of the film layer 20 is shown in an emphasized manner, and actually, the thickness of the film layer 20 is illustrated as compared with the thickness of the wafer 10 illustrated. It is much thinner (the same applies to FIG. 7 described later).

  In FIG. 4, in the field of view F1 of the first camera unit 130a, the actual imageable range L1 in the direction crossing the circumferential direction of the wafer 10 to be inspected is substantially between the upper outer peripheral bevel surface 12U and the upper surface 11a. A range between the first boundary edge 15a serving as a boundary and the second boundary edge 15b serving as a boundary between the upper outer peripheral bevel surface 12U and the outer peripheral end surface 12A, and substantially matches the range of the upper outer peripheral bevel surface 12U. I'm doing it. This is because the first camera unit 130a arranged so as to face the upper outer peripheral bevel surface 12U does not face the upper surface 11a and the outer peripheral end surface 12A. Under suitable optical conditions such as illumination, even if the field of view F1 of the first camera unit 130a is slightly widened on the upper surface 11a side and the outer peripheral end surface 12A side, the upper surface 11a is higher than the upper outer peripheral bevel surface 12U. This is because the outer peripheral end face 12A is not clearly shown. Therefore, in the captured image, the image portion corresponding to the upper surface 11a and the outer peripheral end surface 12A can be distinguished from the image portion outside the image portion corresponding to the upper outer peripheral bevel surface 12U.

As a result, it corresponds to the photographing field range F1 extending corresponding to one turn (360 degrees) from the reference position (0 degrees) in the circumferential direction of the wafer 10 obtained from the image signals sequentially output from the first camera unit 130a. The photographed image is, for example, as shown in FIG. In FIG. 5A, this photographed image includes an upper outer periphery bevel surface image portion I _12U corresponding to the upper outer periphery bevel surface 12U (shootable range L1), and both sides thereof in a direction crossing the circumferential direction (θ direction). Outer image portions I _BUK and I _BKL are formed. One outer image portion I _BKU corresponds to the upper surface outer peripheral portion adjacent to the upper outer peripheral bevel surface _12U , and the boundary line E _15a between the upper outer peripheral bevel surface image portion I _12U and the outer outer image portion I _BKU is the upper outer peripheral portion. This corresponds to the first boundary edge 15a (see FIG. 4), which is the boundary between the bevel surface 12U and the upper surface 11a. The other outer image portion I _BKL corresponds to the outer peripheral end surface 12A, and the boundary line E _15b between the upper outer peripheral bevel surface image portion I _12U and this outer image portion I _BKL is the upper outer peripheral bevel surface 12U and the outer peripheral end surface. This corresponds to the second boundary edge 15b (see FIG. 4), which is the boundary with 12A. A film layer image portion I _12U (20) corresponding to the film layer 20 is formed on the upper outer peripheral bevel surface image portion I _12U .

  Returning to FIG. 4, in the field-of-view range F2 of the second camera unit 130b, the actual imageable range L2 in the direction crossing the circumferential direction of the wafer 10 to be imaged is effectively the outer peripheral end surface 12A and the upper outer peripheral bevel surface. 12U is a range between the second boundary edge 15b serving as a boundary with 12U and the third boundary edge 15c serving as a boundary between the outer peripheral end surface 12A and the lower outer peripheral bevel surface 12L, and is approximately within the range of the outer peripheral end surface 12A. It matches. Similarly to the above, the second camera unit 130b arranged so as to face the outer peripheral end surface 12A does not have a relationship facing the upper outer peripheral bevel surface 12U and the lower outer peripheral bevel surface 12L. The optical field of view F2 of the second camera unit 130b slightly extends to the upper outer peripheral bevel surface 12U side and the lower outer peripheral bevel surface 12L side under optical conditions such as illumination suitable for photographing the outer peripheral end surface 12A. This is because the upper outer peripheral bevel surface 12U and the lower outer peripheral bevel surface 12L are not clearly shown as compared with the outer peripheral end surface 12A. Also in this case, on the captured image, it is possible to distinguish the image portion corresponding to the upper outer peripheral bevel surface 12U and the lower outer peripheral bevel surface 12L as the image portion outside the image portion corresponding to the outer peripheral end surface 12A.

As a result, the photographed image corresponding to the photographing field range F2 corresponding to the circumferential direction of the wafer 10 obtained from the image signals sequentially output from the second camera unit 130b is, for example, as shown in FIG. Become. In FIG. 5B, this captured image includes an outer peripheral end surface image portion I _12A corresponding to the outer peripheral end surface 12A (shootable range L2), and both sides in the direction crossing the circumferential direction (θ direction) are the outer image portions I. _BKU and I _BKL . One outer image portion I _BKU corresponds to the upper outer peripheral bevel surface 12U, and a boundary line E _15b between the outer peripheral end surface image portion I _12A and this outer image portion I _BKU is the outer peripheral end surface 12A and the upper outer peripheral bevel surface 12U. Corresponds to the second boundary edge 15b (see FIG. 4). The other outer image portion I _BKL corresponds to the lower outer peripheral bevel surface 12L, and the boundary line E _15c between the outer peripheral end surface image portion I _12A and the outer image portion I _BKL is the outer peripheral end surface 12A and the lower outer peripheral bevel surface. This corresponds to the third boundary edge 15c (see FIG. 4), which is the boundary with 12L. A film layer image portion I _12A (20) corresponding to the film layer 20 is formed on the outer peripheral end face image portion I _12A .

By the way, in the photographed image (see FIG. 5A) corresponding to the field of view F1 of the first camera unit 130a (see FIG. 5A), the boundary line E between the upper outer peripheral bevel surface image portion I _12U and the outer image portions I _BKU and I _{BKL. 15a,} E _15b, it corresponds to the second boundary edge 15b serving as a boundary between the first boundary edge 15a, the upper outer circumference bevel surface 12U and the outer peripheral end face 12A at the boundary between the upper outer circumference bevel surface 12U and the upper surface 11a Therefore, the vertical position (Y) representing the position in the direction crossing the circumferential direction is essentially the same at each position in the circumferential direction, that is, appears as a straight line on the captured image. Further, also in a captured image corresponding to the field-of-view range F2 of the second camera unit 130b (see FIG. 5B), a boundary line E _15b between the outer peripheral end surface image portion I _12A and each of the outer image portions I _BKU and I _BKL. E _15c should appear as a straight line on the photographed image.

However, these boundary lines E _15a , E _15b , and E _15c on the captured image are not straight lines as shown in FIGS. 5 (a) and 5 (b). That is, the vertical position (Y) at each position (θ) in the circumferential direction of each boundary line E _15a , E _15b , E _15c varies. This is due to the following reason.

The upper outer peripheral bevel surface 12U, the outer peripheral end surface 12A, and the lower outer peripheral bevel surface 12L in the outer peripheral portion of the wafer 10 are caused, for example, as shown in FIGS. 6 (a), 6 (b), and 6 (c). In addition, the width and the inclination angle can vary variously at each position (θ) in the circumferential direction. For this reason, the first boundary edge 15a, the second boundary edge 15b, the third boundary edge 15c, and the fourth boundary edge, which are the boundaries of the adjacent surfaces 11a, 12U, 12A, 12L, and 11b in the wafer 10, respectively. The radial position of 15d can vary at each position in the circumferential direction. Thus, since the positions of the boundary edges 15a, 15b, and 15c serving as the boundaries between adjacent surfaces in the outer peripheral portion of the wafer 10 fluctuate, each surface image portion on the photographed image corresponding to the boundary edge ( The boundary lines E _15a , E _15b , E _15c between the upper outer peripheral bevel surface image portion I _12U and the outer peripheral end surface image portion I _12A ) and the outer image portions I _BKU , I _BKL are straight lines (each in the circumferential direction). The position in the vertical direction is not constant).

  Such a phenomenon can occur not only for each wafer 10 but also between individual wafers 10.

  Under such circumstances, the film on each surface (the upper surface 11a, the upper and outer peripheral bevel surfaces 12U, the outer peripheral end surface 12A, the lower outer peripheral bevel surface 12L, and the lower surface 11b) is directly taken from the captured image as shown in FIGS. It is difficult to quantitatively evaluate (inspect) the formation position of the layer 20, for example, the position of the edge line of the film layer 20 with high accuracy.

  The inspection apparatus according to the embodiment of the present invention can quantitatively evaluate the formation position of the film layer on the wafer surface. This will be specifically described below.

  As shown in FIG. 7, for example, the wafer 10 to be inspected has four film layers 21, 22, 23, 24 formed on the surface thereof. At a certain position (θ) in the circumferential direction of the wafer 10, as shown in FIG. 7, the first film layer 21 reaches the lower outer peripheral bevel surface 12L from the upper surface 11a through the upper outer peripheral bevel surface 12U and the outer peripheral end surface 12A. Yes. The second film layer 22 is stacked on the first film layer 21 and reaches the outer peripheral end surface 12A from the upper surface 11a of the wafer 10 through the upper outer peripheral bevel surface 12U. The third film layer 23 is stacked on the second film layer 22 and reaches the outer peripheral end surface 12A from the upper surface 11a of the wafer 10 through the upper outer peripheral bevel surface 12U. Further, the fourth film layer 24 is laminated on the third film layer 23 on the upper surface 11a without reaching the upper and outer peripheral bevel surfaces 12U of the wafer 10.

With respect to such a wafer 10, five camera units 130a to 130e are arranged in the same manner as shown in FIG. That is, the field of view F1 of the first camera unit 130a facing the upper outer peripheral bevel surface 12U includes the upper outer peripheral bevel surface 12U and slightly extends to the upper surface 11a side and the outer peripheral end surface 12A side. A range between the first boundary edge portion 15a and the second boundary edge portion 15b corresponding to is a shootable range L1 of the first camera unit 130a. The field-of-view range F2 of the second camera unit 130b facing the outer peripheral end surface 12A includes the outer peripheral end surface 12A, slightly extends to the upper outer peripheral bevel surface 12U side and the lower outer peripheral bevel surface 12L side, and corresponds to the outer peripheral end surface 12A. A range between the second boundary edge portion 15b and the third boundary edge portion 15c is a shootable range L2 of the second camera unit 130b. The field of view F3 of the third camera unit 130c facing the lower outer peripheral bevel surface 12L includes the lower outer peripheral bevel surface 12L and slightly extends toward the outer peripheral end surface 12A side and the lower surface 11b side. A range between the third boundary edge portion 15c and the fourth boundary edge portion 15d corresponding to is a shootable range L3 of the third camera unit 130c.

  Furthermore, the field-of-view range F4 of the fourth camera unit 130d that directly faces the outer peripheral portion of the upper surface (the region adjacent to the upper and outer peripheral bevel surface 12U of the upper surface 11a) includes the upper outer peripheral portion and slightly toward the upper outer peripheral bevel surface 12U side. The range from the first boundary line portion 15a corresponding to the outer peripheral portion of the upper surface to the opposite limit of the imaging visual field range F4 is a shootable range L4 of the fourth camera unit 130d. In addition, the field-of-view range F5 of the fifth camera unit 130e that directly faces the lower surface outer peripheral portion (the region adjacent to the lower outer peripheral bevel surface 12L of the lower surface 11b) includes the lower surface outer peripheral portion and slightly toward the lower outer peripheral bevel surface 12L side. The range from the fourth boundary edge 15d corresponding to the outer peripheral portion of the lower surface to the opposite limit of the imaging field of view range F5 is the imaging possible range L5 of the fifth camera unit 130e.

  The processing unit 200 that sequentially inputs the image signals output from the camera units 130a to 130e in which the captured image ranges F1 to F5 are set as described above performs processing according to the procedure shown in FIGS.

  In FIG. 8, the processing unit 200 performs drive control of the rotational drive motor 110 to rotate the stage 100 in a predetermined direction at a predetermined speed (S1). Thereby, the wafer 10 set on the stage 100 rotates. During the rotation of the wafer 10, the processing unit 200 sequentially outputs images from the first camera unit 130a, the second camera unit 130b, the third camera unit 130c, the fourth camera unit 130d, and the fifth camera unit 130e. Based on the signal, photographed image data representing photographed images corresponding to the photographing field ranges F1 to F5 extending corresponding to the circumferential direction of the wafer 10 is generated, and the photographed image data is taken into a predetermined memory (S2).

Specifically, based on the image signal from the first camera unit 130a, the field of view including the upper and outer bevel surfaces 12U extending corresponding to the circumferential direction of the wafer 10 and corresponding to one round (0 to 360 degrees). Based on the image signal from the second camera unit 130b, the first captured image data DI _Ub (θ) representing the first captured image corresponding to the range F1 is similarly applied to the outer peripheral end surface 12A for one turn of the wafer 10. Similarly, the second photographed image data DI _Ap (θ) representing the second photographed image corresponding to the photographing field-of-view range F2 includes a lower portion corresponding to one turn of the wafer 10 based on the image signal from the third camera unit 130c. Third photographed image data ID _Lb (θ) representing the third photographed image corresponding to the photographing field range F3 including the outer peripheral bevel surface 12L is generated. Further, based on the image signal from the fourth camera unit 130d, a fourth view field range F4 corresponding to the imaging visual field range F4 including the upper surface outer peripheral portion (a region adjacent to the upper outer peripheral bevel surface 12U of the upper surface 11a) for one round of the wafer 10 is obtained. Fourth photographed image data DI _Sa representing the photographed image is generated, and on the basis of the image signal from the fifth camera unit 130e, the lower peripheral portion of the lower surface of the wafer 10 (the lower outer peripheral bevel surface 12L with the lower peripheral surface 11b) Fifth captured image data DI _Sb (θ) representing the fifth captured image corresponding to the captured visual field range F5 including the adjacent region is generated.

  Each photographed image data is represented as grayscale (luminance) information of pixel points determined by a position (θ) in the circumferential direction and a vertical position Y that represents a position in a direction that intersects (for example, orthogonally) the circumferential direction. The origin of the vertical position Y can be arbitrarily determined in the processing unit 200. For example, the end point on the photographed image corresponding to one limit point in the direction crossing the circumferential direction of the photographing field range can be determined as the origin (Y = 0) of the vertical position Y.

When the captured image data ID _Ub , ID _Ap , ID _Lb , ID _Sa , and ID _Sb for one round of the wafer 10 are obtained (YES in S3), the processing unit 200 stops the rotation drive motor 110 and stops the wafer 10. Is stopped (S4), and the processing relating to captured image capture is terminated.

The first captured image represented by the first captured image data DI _Ub is, for example, as shown in FIGS. 11B and 12A. This first photographed image includes an upper outer periphery bevel surface image portion I _12U , and both sides thereof in the direction crossing the circumferential direction are outer image portions I _BUK and I _BKL . One outer image portion I _BKU corresponds to the upper surface outer peripheral portion adjacent to the upper outer peripheral bevel surface _12U , and the boundary line E _15a between the upper outer peripheral bevel surface image portion I _12U and the outer outer image portion I _BKU is the upper outer peripheral portion. This corresponds to the first boundary edge 15a (see FIG. 7), which is the boundary between the bevel surface 12U and the upper surface 11a. The other outer image portion I _BKL corresponds to the outer peripheral end surface 12A, and the boundary line E _15b between the upper outer peripheral bevel surface image portion I _12U and this outer image portion I _BKL is the upper outer peripheral bevel surface 12U and the outer peripheral end surface. This corresponds to the second boundary edge 15b (see FIG. 7), which is the boundary with 12A. On the upper outer peripheral bevel surface image portion I _12U , the second film layer image portion I _12U (22) corresponding to the second film layer 22 and the third film layer image portion I _12U (23 corresponding to the third film layer 23). ) Is formed. In the first captured image, an edge line E _{23 of} the third film layer image portion I _12U (23) corresponding to the third film layer 23 overlapping the second film layer 22 appears.

The second photographed image represented by the second photographed image data DI _Ap is as shown in, for example, FIGS. 12B and 13A. The second photographed image includes an outer peripheral end face image portion I _12A , and both sides thereof in the direction crossing the circumferential direction are outer image portions I _BUK and I _BKL . One outer image portion I _BKU corresponds to the upper outer peripheral bevel surface 12U adjacent to the outer peripheral end surface _12A , and a boundary line E _15b between the outer peripheral end surface image portion I _12A and the outer image portion I _BKU is _separated from the outer peripheral end surface 12A. This corresponds to the second boundary edge 15b (see FIG. 7), which is the boundary with the upper outer peripheral bevel surface 12U. The other outer image portion I _BKL corresponds to the lower outer peripheral bevel surface 12L, and a boundary line E _15c between the outer peripheral end surface image portion I _12A and this outer image portion I _BKL is the outer peripheral end surface 12A and the lower outer peripheral bevel surface. This corresponds to the third boundary edge 15c (see FIG. 7), which is the boundary with 12L. On the outer peripheral end face image portion I _12A , a first film layer image portion I _12A (21) corresponding to the first film layer 21, a second film layer image portion I _12A (22) corresponding to the second film layer 22, and A third film layer image portion I _12A (23) corresponding to the third film layer 23 is formed. The second photographed image overlaps the edge line E _{22 of} the second film layer image portion I _12A (22) corresponding to the second film layer 22 overlapping the first film layer 21 and the second film layer 22. An edge line E _{23 of} the third film layer image portion I _12A (23) corresponding to the third film layer ₂₃ appears.

The third captured image represented by the third captured image data DI _Lb is as shown in, for example, FIGS. 13B and 14A. The third photographed image includes a lower outer peripheral bevel surface image portion I _12L , and both sides thereof in the direction crossing the circumferential direction are outer image portions I _BUK and I _BKL . One outer image portion I _BKU corresponds to the outer peripheral end surface 12A adjacent to the lower outer peripheral bevel surface _12L , and a boundary line E _15c between the lower outer peripheral bevel surface image portion I _12L and the outer outer image portion I _BKU is represented by This corresponds to the third boundary edge 15c (see FIG. 7), which is the boundary between the bevel surface 12L and the outer peripheral end surface 12A. The other outer image portion I _BKL corresponds to the outer peripheral portion of the lower surface, and a boundary line E _15d between the lower outer peripheral bevel surface image portion I _12L and the outer image portion I _BKL has a lower outer peripheral bevel surface 12L and a lower surface 11b. Corresponds to the fourth boundary edge 15d (see FIG. 7). On the lower outer peripheral bevel surface image portion I _12L , the first film layer image portion I _12L (21) corresponding to the first film layer 21 and the second film layer image portion I _12L (22 corresponding to the second film layer 22). ) Is formed. In the third captured image, the second film layer image portion I _12L corresponding to the edge line E _{21 of} the first film layer image portion I _12L (21) and the second film layer 22 overlapping the first film layer 21. edge line E ₂₂ is a sign of (22).

For example, the fourth captured image represented by the fourth captured image data DI _Sa is as shown in FIG. This fourth photographed image includes an upper surface image portion I _Sa (corresponding to a region adjacent to the upper outer peripheral bevel surface 12U of the upper surface 11a), and one side thereof in the direction crossing the circumferential direction is an outer image portion I _BKL . The outer image portion I _BKL corresponds to the upper outer peripheral bevel surface 12U, and a boundary line E _15a between the upper image portion I _Sa and the outer image portion I _BKL is a boundary between the upper surface 11a and the upper outer peripheral bevel surface 12U. It corresponds to a certain first boundary edge 15a (see FIG. 7). A third film layer image portion _Isa (23) corresponding to the third film layer 23 and a fourth film layer image portion _Isa (24) corresponding to the fourth film layer 24 are formed on the upper surface image portion _Isa. Has been. In the fourth captured image, an edge line E _{24 of} the fourth film layer image portion I _Sa (24) corresponding to the fourth film layer 24 overlapping the third film layer 23 appears.

Fifth captured image expressed by a fifth captured image data DI _Sb is, for example, as shown in FIG. 14 (b). This fifth photographed image includes a lower surface image portion I _Sb (corresponding to a portion adjacent to the lower outer peripheral bevel surface 12L of the lower surface 11a), and one side thereof in the direction crossing the circumferential direction is an outer image portion I _BKU . The background image portion I _BKU corresponds to the lower outer peripheral bevel surface 12L, and the boundary line E _15d between the lower surface image portion I _Sb and the outer image portion I _BKU is the boundary between the lower surface 11b and the lower outer peripheral bevel surface 12L. This corresponds to a fourth boundary edge 15d (see FIG. 7). In this example, no image portion corresponding to the film layer particularly appears on the lower surface image portion _ISb .

Processing unit 200 which has obtained the first photographic image data DI _Ub ~ fifth captured image data DI _Sb according to the procedure shown in FIG. 8 carries out the processing according to the procedure shown in FIGS. 9 and 10.

First, in FIG. 9, the processing unit 200 starts from the first photographed image data DI _Ub , as shown in FIG. 16A, the outer peripheral bevel surface image portion I _12U and the outer image on the upper surface 11a side on the first photographed image. The boundary line E _15a with the part I _BKU is extracted by a general edge extraction method to detect the vertical position Y _E15a (θ) at each circumferential position (θ), and the upper outer peripheral bevel surface image Similarly, the boundary line E _15b between the I _12U and the outer image portion I _BKL on the outer peripheral end face 12A side is extracted to detect the longitudinal position Y _E15bL (θ) at each circumferential position (θ) (S11). . Next, as shown in FIG. 17A, the processing unit 200 uses the second photographed image data DI _Ap to _obtain the outer peripheral end face image portion I _12A on the second photographed image and the outer image portion I _BKU on the upper outer peripheral bevel surface 12U side. longitudinal position Y _E15b (θ) is detected and the background image portion of the outer peripheral end face image part I _12A and the lower outer circumference bevel surface 12L side at each position in the circumferential direction by extracting the boundaries E _15b (theta) with The boundary line E _15c with I _BKL is extracted, and the longitudinal position Y _E15cL (θ) at each circumferential position (θ) is detected (S12). Then, the processing unit 200 determines from the third photographed image data DI _Lb the lower outer peripheral bevel surface image portion I _12L and the outer image portion I _BKU on the outer peripheral end surface 12A side on the third photographed image as shown in FIG. longitudinal position Y _E15c (θ) is detected and the lower outer circumference bevel surface image part I _12L and the lower surface 11b side of the outer image part I at each position in the circumferential direction by extracting the boundaries E _15c (theta) with The boundary line E _15d with the _BKL is extracted and the longitudinal position Y _E15dL (θ) at each circumferential position (θ) is detected (S13).

Further, the processing unit 200 _obtains the upper image portion I _Sa on the fourth photographed image and the outer image portion I _BKL on the upper outer peripheral bevel surface 12U side from the fourth photographed image data DI _Sa as shown in FIG. The boundary line E _15a is extracted and the longitudinal position Y _E15aL (θ) at each circumferential position (θ) is detected (S14). Next, the processing unit 200, from the fifth captured image data _DISB , as shown in FIG. 19A, the lower surface image portion I _Sb on the fifth captured image and the outer image portion I _BKU on the lower outer peripheral bevel surface 12L side The boundary line E _15d is extracted, and the vertical position Y _E15d (θ) at each circumferential position (θ) is detected (S15).

Then, the processing unit 200, the image data _{DI Ub, DI Ap, DI Lb} , DI Sa, the correction processing of DI _Sb performed (S16). This correction processing is performed as follows.

For the first photographed image data DI _Ub , at each position (θ) in the circumferential direction of the boundary line E _15a between the upper outer peripheral bevel surface image portion I _12U and its outer image portion I _BKU on the corresponding first photographed image. With reference to the vertical position Y _E15a (θ), the vertical position Y ₁ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point on the first photographed image is corrected to be expressed. The Specifically, as shown in FIG. 16B, the vertical position Y ₁ (θ) at each circumferential position (θ) of the boundary line E _15a is set to zero (Y ₁ = 0), and each pixel The vertical position Y ₁ (θ) at the corresponding position (θ) in the circumferential direction of the point is expressed as a distance value from the boundary line E _15a . That is, the vertical position Y ₁ (θ) at each position (θ) in the circumferential direction of each pixel point on the first photographed image after correction is a corresponding position in the circumferential direction of the boundary line E _15a before correction ( The vertical position Y _E15a (θ) at θ) and the vertical position Y (θ) at the corresponding position (θ) in the circumferential direction of the corresponding pixel point before correction,
Y ₁ (θ) = Y (θ) −Y _E15a (θ)
It is expressed.

By such correction of the first captured image data DI _Ub , as shown in FIG. 16B, the boundary line E _15b on the other side of the upper outer peripheral bevel surface image I _12U on the corrected first captured image is displayed. longitudinal position Y _1E15b at each position in the circumferential direction (θ) (θ) is used longitudinal position Y _E15bL (θ) in the circumferential direction of the corresponding position of the pre-correction of the same boundary line E _15b (theta) Similarly,
Y _1E15b (θ) = Y _E15bL (θ) −Y _E15a (θ)
It is expressed.

In addition, the vertical position Y at each circumferential position (θ) of the edge line E ₂₃ of the third film layer image portion I _12U (23) corresponding to the third film layer 23 on the first photographed image after correction. _1E23 (θ) (film layer edge position information) is similarly calculated using the corresponding vertical position Y _E23 (θ) in the circumferential direction of the same edge line E ₂₃ before correction.
Y _1E23 (θ) = Y _E23 (θ) −Y _E15a (θ)
It is expressed.

For the second captured image data DI _Ap , the vertical direction at each circumferential position (θ) of the boundary line E _15b between the outer peripheral end face image portion I _12A and the outer image portion I _BKU on the corresponding second captured image. Using the position Y _E15b (θ) as a reference, the vertical position Y ₂ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point on the second photographed image is corrected. Specifically, as shown in FIG. 17B, the vertical position Y ₂ (θ) at each circumferential position (θ) of the boundary line E _15b is set to zero (Y ₂ = 0), and each pixel The vertical position Y ₂ (θ) at the corresponding position (θ) in the circumferential direction of the point is represented as a distance value from the boundary line E _15b . That is, the vertical position Y ₂ (θ) at each position (θ) in the circumferential direction of each pixel point on the second captured image after correction is a corresponding position in the circumferential direction of the boundary line E _15b before correction ( The vertical position Y _E15b (θ) at θ) and the vertical position Y (θ) at the corresponding position (θ) in the circumferential direction of the corresponding pixel point before correction,
Y ₂ (θ) = Y (θ) −Y _E15b (θ)
It is expressed.

By correcting the second photographed image data DI _Ap as described above, as shown in FIG. 17B, the circumferential direction of the boundary line E _15c on the other side of the outer peripheral end face image I _12A on the second photographed image after correction. longitudinal position Y _2E15c (θ) at each position (theta) of using the longitudinal position Y _E15cL (θ) in the circumferential direction of the corresponding position of the pre-correction of the same boundary line E _15c (theta), Similarly,
Y _2E15c (θ) = Y _E15cL (θ) −Y _E15b (θ)
It is expressed.

Further, the vertical position Y at each circumferential position (θ) of the edge line E ₂₃ of the third film layer image portion I _12A (23) corresponding to the third film layer 23 on the corrected second photographed image. _2E23 (θ) (film layer edge position information) is similarly calculated using the vertical position Y _E23 (θ) at the corresponding position (θ) in the circumferential direction of the edge line E ₂₃ before correction.
Y _2E23 (θ) = Y _E23 (θ) −Y _E15b (θ)
And a longitudinal position Y _2E22 (θ) at each circumferential position (θ) of the edge line E ₂₂ of the second film layer image portion I _12A (22) corresponding to the second film layer 22. The film layer edge position information) is similarly calculated using the vertical position Y _E22 (θ) at the corresponding position (θ) in the circumferential direction of the same edge line E ₂₂ before correction.
Y _2E22 (θ) = Y _E22 (θ) −Y _E15b (θ)
It is expressed.

With respect to the third photographed image data DI _Lb , at each circumferential position (θ) of the boundary line E _15c between the lower outer peripheral bevel surface image portion I _12L and the outer image portion I _BKU on the corresponding third photographed image. With reference to the vertical position Y _E15c (θ), the vertical position Y ₃ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point on the third photographed image is corrected to be expressed. The Specifically, as shown in FIG. 18B, the vertical position Y ₃ (θ) at each circumferential position (θ) of the boundary line E _15c is set to zero (Y ₃ = 0), and each pixel The vertical position Y ₃ (θ) at the corresponding position (θ) in the circumferential direction of the point is represented as a distance value from the boundary line E _15c . That is, the vertical position Y ₃ (θ) at each position (θ) in the circumferential direction of each pixel point on the third photographed image after correction is a corresponding position in the circumferential direction of the boundary line E _15c before correction ( The vertical position Y _E15c (θ) at θ) and the vertical position Y (θ) at the corresponding position (θ) in the circumferential direction of the corresponding pixel point before correction,
Y ₃ (θ) = Y (θ) −Y _E15c (θ)
It is expressed.

By such correction of the third photographed image data DI _Lb , as shown in FIG. 18B, the boundary line E _15d on the other side of the lower outer peripheral bevel surface image portion I _12L on the third photographed image after correction. circumferential longitudinal position Y _3E15d (θ) at each position (theta) of the longitudinal position Y _E15dL in the circumferential direction of the corresponding position of the pre-correction of the same boundary line E _15d (theta) a (theta) As well as
Y _3E15d (θ) = Y _E15dL (θ) −Y _E15c (θ)
It is expressed.

Further, the vertical position Y at each circumferential position (θ) of the edge line E ₂₂ of the second film layer image portion I _12L (22) corresponding to the second film layer 22 on the corrected third photographed image. _3E22 (θ) (film layer edge position information) is similarly calculated using the vertical position Y _E22 at the position (θ) corresponding to the circumferential direction of the edge line E ₂₂ before correction,
Y _3E22 (θ) = Y _E22 (θ) −Y _E15c (θ)
And a vertical position Y _3E21 (film layer edge) at each circumferential position (θ) of the edge line E ₂₁ of the first film layer image portion I _12L (21) corresponding to the first film layer 21. (Position information) is similarly calculated using the vertical position Y _E21 (θ) at the corresponding position (θ) in the circumferential direction of the same edge line E ₂₁ before correction,
Y _3E21 (θ) = Y _E21 (θ) −Y _E15c (θ)
It is expressed.

For the fourth photographed image data DI _Sa , the vertical direction at each circumferential position (θ) of the boundary line E _15a between the upper image portion I _Sa and the outer image portion I _BKL on the corresponding fourth photographed image. With reference to the direction position Y _E15aL (θ), the vertical position Y ₄ (θ) at the position (θ) corresponding to the circumferential direction of each pixel point on the fourth photographed image is corrected. . Specifically, as shown in FIG. 15B, the vertical position Y ₄ (θ) at each circumferential position (θ) of the boundary line E _15a is set to zero (Y ₄ = 0), and each pixel The vertical position Y ₄ (θ) at the corresponding position (θ) in the circumferential direction of the point is represented as a distance value from the boundary line E _15a . That is, the vertical position Y ₄ (θ) at each position (θ) in the circumferential direction of each pixel point on the fourth photographed image after correction is a corresponding position in the circumferential direction of the boundary line E _15a before correction ( The vertical position Y _E15aL (θ) at θ) and the vertical position Y (θ) at the corresponding position in the circumferential direction of the corresponding pixel point before correction,
Y ₄ (θ) = Y (θ) −Y _E15aL (θ)
It is expressed.

By such correction of the fourth captured image data DI _Sa , the circumferential direction of the edge line E ₂₄ of the fourth film layer image portion I _Sb (24) corresponding to the fourth film layer 24 on the corrected fourth captured image. The vertical position Y _4E24 (θ) (film layer edge position information) at each position (θ) is the vertical position Y _E24 at the position (θ) corresponding to the circumferential direction of the same edge line E ₂₄ before correction. Similarly, using (θ)
Y _4E24 (θ) = Y _E24 (θ) −Y _E15aL (θ)
It is expressed.

Furthermore, for the fifth captured image data DI _Sb, vertical in each position in the circumferential direction of the corresponding fifth lower surface image part I _Sb on the captured image and the boundary line E _15d with its outer image part I _BKU (theta) With reference to the direction position Y _E15d (θ), the vertical position Y ₅ (θ) at the position (θ) corresponding to the circumferential direction of each pixel point on the fifth captured image is corrected to be expressed. . Specifically, as shown in FIG. 19B, the vertical position Y ₅ (θ) at each circumferential position (θ) of the boundary line E _15d is set to zero (Y ₅ = 0), and each pixel The vertical position Y ₅ (θ) at the corresponding position (θ) in the circumferential direction of the point is represented as a distance value from the boundary line E _15d . That is, the vertical position Y ₅ (θ) at each position (θ) in the circumferential direction of each pixel point on the fifth photographed image after correction is the corresponding position in the circumferential direction of the boundary line E _15d before correction ( The vertical position Y _E15d (θ) at θ) and the vertical position Y (θ) at the corresponding position in the circumferential direction of the corresponding pixel point before correction,
Y ₄ (θ) = Y (θ) −Y _E15d (θ)
It is expressed.

Captured image data DI _Ub as described _{above, DI Ap, DI Lb, DI} Sa, the correction processing of DI _Sb (S16) is completed, the processing unit 200 proceeds to the processing shown in FIG. 10, is the corrected A composite image (composite image data) is generated from the captured image data DI _Ub , DI _Ap , DI _Lb , DI _Sa , and DI _sb (S17). The composite image is generated as follows.

In the process of generating the composite image, for example, the boundary line E _15a between the upper-surface outer bevel surface image portion I _12U and the outer image portion I _BKU included in the first captured image represented by the first captured image data DI _Ub is obtained. It is determined as the reference boundary line.

A boundary line E _15a (see FIG. 16) between the upper outer peripheral bevel surface image portion I _12U and the outer image portion I _BKU that is the reference for the correction in the first captured image, and the reference for the correction in the fourth captured image The upper outer peripheral bevel surface image portion I _12U and the upper surface image portion _Isa are joined so as to match the boundary line E _15a (see FIG. 15) between the upper surface image portion I _Sa and the outer image portion I _BKL . . Further, a boundary line E _15b (see FIG. 16) between the upper outer peripheral bevel surface image portion I _12U and the outer image portion I _BKL, and the outer peripheral end surface image portion I _{12A that} is the reference for the correction in the second photographed image and the outer side The upper outer peripheral bevel surface image portion I _12U and the outer peripheral end surface image portion I _12A are joined so as to match the boundary line E _15b (see FIG. 17) with the image portion I _BKU . A boundary line E _15c (see FIG. 17) between the outer peripheral end face image portion I _12A and the outer image portion I _BKL, and a lower outer peripheral bevel surface image I _12L and an outer image portion I that are the reference for the correction in the third photographed image. _The outer peripheral end face image portion I _12A and the lower outer peripheral bevel surface image portion I _12L are joined so as to match the boundary line E _15c (see FIG. 18) with the _BKU . Further, a boundary line E _15d (see FIG. 18) between the lower outer peripheral bevel surface image I _12L and the outer image portion I _BKL, and the lower surface image portion I _Sb and the outer image portion that are the reference for the correction in the fifth photographed image. The lower outer peripheral bevel surface image portion I _12L and the lower surface image portion I _Sb are joined so as to match the boundary line E _15d with I _BKU (see FIG. 19).

In this way, the upper image portion I _Sa , the upper outer peripheral bevel surface image portion I _12U , the outer peripheral end surface image portion I _12A , the lower outer peripheral bevel surface image portion I _12L, and the lower surface image portion I _{Sb, which} are included in different captured images, respectively. A combined image as shown in FIG. 20 is generated. In this composite image, the vertical position Y (θ) at each position (θ) in the circumferential direction of each pixel point is a position corresponding to the circumferential direction of the boundary line E _15a of the first photographed image serving as the reference boundary line. Is determined based on the vertical position.

Therefore, as shown in FIG. 20, in the region of the top image portion _Isa of the composite image, the value of the vertical position Y (θ) at each circumferential position (θ) of each pixel point is as described above. The vertical position Y ₄ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point obtained by the correction (see FIG. 15) based on the boundary line E _15a from the fourth photographed image data DI _Sa. It is determined to correspond to the value. For example,
Y (θ) = Y ₄ (θ)
It becomes.

In the region of the upper and outer peripheral bevel surface image portion I _12U of the composite image, the value of the vertical position Y (θ) at each circumferential position (θ) of each pixel point is the first captured image data DI as described above. Corresponding to the value of the vertical position Y ₁ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point obtained by the correction from _Ub with reference to the boundary line E _15a (see FIG. 16). It is decided. For example,
Y (θ) = Y ₁ (θ)
It becomes.

In the region of the outer peripheral end face image portion I _12A of the composite image, the value of the vertical position Y (θ) at each position (θ) in the circumferential direction of each pixel point is the second captured image data DI as described above. _The boundary line is set to the value of the longitudinal position Y ₂ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point obtained by correction based on _{Ap based} on the boundary line E _15b (see FIG. 17). It is determined to correspond to a value obtained by adding the distance (Y _1E15b (θ)) from the reference boundary E _15a at the corresponding position (θ) in the circumferential direction of E _15b . For example,
Y (θ) = Y _1E15b (θ) + Y ₂ (θ)
It becomes.

Further, in the region of the lower outer peripheral bevel surface image portion I _12L of the composite image, the value of the vertical position Y (θ) at each position (θ) in the circumferential direction of each pixel point is the third captured image as described above. The value of the vertical position Y ₃ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point obtained by correction (see FIG. 18) based on the boundary line E _15c from the data DI _Lb It is determined to correspond to a value obtained by adding a distance (Y _1E15b (θ) + Y _2E15c (θ)) from the reference boundary line E _15a at a corresponding position (θ) in the circumferential direction of the boundary line E _15c . For example,
Y (θ) = Y _1E15b (θ) + Y _2E15c (θ) + Y ₃ (θ)
It becomes.

In the area of the lower surface image portion I _Sb of the composite image, the value of the vertical position Y (θ) at each position (θ) in the circumferential direction of each pixel point is the fifth captured image data DI _Sb as described above. To the value of the vertical position Y ₅ (θ) at the corresponding position (θ) in the circumferential direction of each pixel point obtained by the correction based on the boundary line E _15d (see FIG. 19). _It is determined to correspond to a value obtained by adding a distance (Y _1E15b (θ) + Y _2E15c (θ) + Y _3E15d (θ)) from the reference boundary line E _15a at the corresponding position (θ) in the circumferential direction of _15d. . For example,
Y (θ) = Y _1E15b (θ) + Y _2E15c (θ) + Y _3E15d (θ) + Y ₅ (θ)
It becomes.

When a composite image (composite image data) is generated as described above, the processing unit 200 can display a composite image as shown in FIG. 20 on the display unit 220 based on the composite image data. Then, returning to FIG. 10, the processing unit 200, on the composite image, the edge lines E ₂₁ , E ₂₂ , E ₂₃ , E _{24 of} the film layer image portions corresponding to the respective film layers ₂₁ , ₂₂ , ₂₃ , _24. Are detected in accordance with a normal edge detection method (S18). Vertical positions Y _E21 (θ), Y _E22 (θ), Y _E23 (θ), Y _E24 (θ at each circumferential position (θ) of each edge line E ₂₁ , E ₂₂ , E ₂₃ , E ₂₄ ) (Film layer edge position information) can be expressed by a predetermined coordinate system Y-θ on the composite image. However, the longitudinal positions Y _E21 (θ), Y _E22 (θ), Y _E23 (θ), and Y _E24 (θ) at the respective circumferential positions (θ) of the respective edge lines are as described above. The relative relationship based on the vertical position at the position (θ) corresponding to the circumferential direction of the boundary line E _15a on the photographed image is maintained.

Further, the processing unit 200 measures the interval between the edge lines of the film layer image on the composite image obtained as described above (S19). For example, as shown in FIG. 20, between the edge line E ₂₃ of the film layer image portion corresponding to the film layer ₂₃ and the edge line E ₂₄ of the film layer image portion corresponding to the film layer 24 overlapping this film layer 23. Interval Δ _4-3 (θ) (= Y _E24 (θ) −Y _E23 (θ)), the edge line E ₂₂ of the film layer image portion corresponding to the film layer _22, and the film layer 23 overlapping the film layer 22 distance between the film layer image part of the edge line E ₂₃ corresponding to the _{Δ 3-2 (θ) (= Y} E23 (θ) -Y E22 (θ)), the edge lines of the film layer image part corresponding to the film layer 21 and E _21, the interval delta _2-1 the edge line E ₂₂ of the film layer image part corresponding to the film layer 22 overlapping the membrane layer _{21 (θ) (= Y E22} (θ) -Y E21 (θ)) is It is measured on the composite image.

Then, the processing unit 200 has longitudinal positions Y _E21 (θ) and Y _E22 (θ at the circumferential positions (θ) of the edge lines E ₂₁ , E ₂₂ , E ₂₃ , and E ₂₄ of each film layer image portion. ), Y _E23 (θ), Y _E24 (θ) (film layer edge position information), spacing between each edge line Δ _4-3 (θ) (= Y _E24 (θ) −Y _E23 (θ)), Δ _3-2 Wafer to be inspected based on (θ) (= Y _E23 (θ) −Y _E22 (θ)), Δ _2-1 (θ) (= Y _E22 (θ) −Y _E21 (θ)) The evaluation information about the film layers 21 to 24 formed on the surface of the film 10 is generated (S20) This evaluation information is in the circumferential direction of the edge lines E ₂₁ , E ₂₂ , E ₂₃ and E ₂₄ of the film layer image portion. Vertical position Y _E21 (θ), Y _E22 (θ), Y _E23 (θ), Y _E24 (θ) (film layer edge position information) at each position (θ), and the interval Δ _4- between the edge lines _{3 (θ) (= Y E24} (θ) -Y E23 (θ)), Δ 3-2 (θ) (= Y E23 (θ) - _{E22 (θ)), Δ 2-1} (θ) (= Y E22 (θ) even -Y _E21 a (theta) itself comprising a representation in a predetermined format, for example, rank information obtained by threshold processing The information obtained by statistically processing the evaluation information about the plurality of wafers 10 can also be used as the evaluation information.

  The processing unit 200 causes the display unit 220 to display the evaluation information obtained together with the above-described composite image (output process: S21), and then ends the process. The operator determines the quality of the wafer 10 to be inspected and the suitability of the conditions in the process of forming a film layer on the surface of the wafer 10 based on the composite image displayed on the display unit 220 and various evaluation information. be able to.

According to the inspection apparatus as described above, a photographed image corresponding to each photographing field range including the outer peripheral portion of the upper surface of the wafer 10, the upper outer peripheral bevel surface 12U, the outer peripheral end surface 12A, the lower outer peripheral bevel surface 12L, and the lower peripheral portion. Generating composite image data representing a composite image (see FIG. 20) in which a plurality of surface image portions corresponding to those surfaces are joined so as to match their corresponding boundary lines, Since the composite image is displayed on the display unit 220 based on the composite image data, from the composite image displayed on the display unit 220, the continuous upper surface outer peripheral portion of the wafer 10, the upper outer peripheral bevel surface 12U, the outer peripheral It is possible to comprehensively grasp the state of the end surface 12A, the lower outer peripheral bevel surface 12L, and the lower surface outer peripheral portion. Specifically, the upper surface 11a, the upper outer peripheral bevel surface 12U, the outer peripheral end surface 12A, and the lower outer peripheral bevel of the wafer 10 are determined based on the film layer edge position information indicating the edge line of the film layer image portion corresponding to the film layer on the composite image. Regardless of the film layer formed on the surface 12L or the lower surface 11b, the position of the edge line can be expressed by a uniform reference, and the film layer formed position on the surface of the wafer 10 Can be accurately and quantitatively evaluated (inspected). More specifically, as shown in FIG. 20, even if the distance between the edge lines of two film layers formed on different surfaces, the distance Δ between the edge lines of the corresponding two film layer image portions. _4-3 , Δ _3-2 and Δ _2-1 can be quantitatively evaluated.

Further, it is determined on the basis of the vertical position at each position in the circumferential direction of the boundary line E _15a on the photographed image corresponding to the first boundary edge 15a serving as the boundary between the upper surface 11a and the upper outer peripheral bevel surface 12U. Since the vertical position at the position corresponding to the circumferential direction of the edge line of the film layer image portion on the synthesized image is obtained as the film layer edge position information, the edge position of each film layer is determined by the film layer edge position information. Evaluation can be made with reference to the first boundary edge portion 15a which is the boundary between the upper surface 11a and the upper outer peripheral bevel surface 12U. Therefore, the position of the edge line of the film layer on the wafer 10 can be quantitatively evaluated with high accuracy.

  The plurality of surfaces to be imaged are not the five surfaces described above, but two consecutive surfaces of the upper surface outer peripheral portion, the upper outer peripheral bevel surface 12U, the outer peripheral end surface 12A, the lower outer peripheral bevel surface 12L, and the lower surface outer peripheral portion. If it is. In particular, when it is desired to particularly evaluate the state of the film layer entering the upper outer peripheral bevel surface 12U, the outer peripheral end surface 12A, and the lower outer peripheral bevel surface 12L of the wafer 10, only those surfaces are to be imaged (inspected), A composite image can also be generated from a photographed image obtained by photographing a surface.

  As described above, the disk-shaped substrate inspection apparatus according to the present invention can quantitatively inspect the formation position of the film layer formed on the surface of the disk-shaped substrate. This is useful as a disk-shaped substrate inspection apparatus for photographing and inspecting the outer peripheral portion of the disk-shaped substrate.

It is a figure which shows typically the principal part of the imaging | photography system of the edge inspection apparatus of the semiconductor wafer as a disk-shaped board | substrate inspection apparatus which concerns on embodiment of this invention. It is a figure which shows the imaging | photography visual field range of five camera units with respect to the outer peripheral part of a semiconductor wafer. It is a block diagram which shows typically the principal part of the processing system of the edge inspection apparatus of the semiconductor wafer as a disk-shaped board | substrate inspection apparatus which concerns on one Embodiment of this invention. It is a figure which shows the imaging | photography visual field range F1, F2 of the 1st camera unit and 2nd camera unit with respect to the semiconductor wafer in which the film layer was formed on the surface, and the imaging | photography range L1, L2 on a wafer. An image example (a) obtained by the first camera unit for photographing the upper and outer peripheral bevel surfaces in the outer peripheral portion of the semiconductor wafer shown in FIG. 4, and an image example (b) obtained by the second camera unit for photographing the outer peripheral end surface. FIG. It is a figure which shows the dispersion | variation in the shape of the outer peripheral part of a semiconductor wafer. It is a figure which shows the imaging | photography visual field range and each imaging | photography range on a wafer with respect to the semiconductor wafer with which four film layers, the 1st film layer-the 4th film layer, were formed on the surface. FIG. 4 is a flowchart (No. 1) showing processing in a processing unit in the processing system shown in FIG. 3. FIG. FIG. 4 is a flowchart (No. 2) showing processing in a processing unit in the processing system shown in FIG. 3. FIG. FIG. 4 is a flowchart (No. 3) illustrating processing in a processing unit in the processing system illustrated in FIG. 3. FIG. An image example (a) obtained by the fourth camera unit for photographing the upper surface of the outer peripheral portion of the semiconductor wafer shown in FIG. 7, and an image example (b) obtained by the first camera unit for photographing the upper outer peripheral bevel surface at the outer peripheral portion. FIG. An image example (a) obtained by the first camera unit for photographing the upper and outer peripheral bevel surfaces in the outer peripheral portion of the semiconductor wafer shown in FIG. 7, and an image example (b) obtained by the second camera unit for photographing the outer peripheral end surface FIG. An image example (a) obtained by the second camera unit for photographing the outer peripheral end surface of the outer peripheral portion of the semiconductor wafer shown in FIG. 7, and an image example (b) obtained by the third camera unit for photographing the lower outer peripheral bevel surface FIG. An image example (a) obtained by the third camera unit that photographs the lower outer peripheral bevel surface in the outer peripheral portion of the semiconductor wafer shown in FIG. 7, and an image obtained by the fifth camera unit that photographs the lower surface in the outer peripheral portion of the semiconductor wafer. It is a figure which shows an example (b). (A) showing a position Y on an image obtained by the fourth camera unit and including an edge line E ₂₄ of the fourth film layer image and a boundary line E _15a corresponding to the first boundary edge 15a of the semiconductor wafer; FIG. 6B is a diagram (b) showing a correction position Y ₄ on an image obtained by correcting the position Y with reference to a boundary line position Y _E15a (θ) corresponding to the first boundary edge 15a. An edge line E ₂₃ of the third film layer image obtained by the first camera unit, a boundary line E _15a corresponding to the first boundary edge 15a of the semiconductor wafer, and a boundary line E _15b corresponding to the second boundary edge _15b and FIG. (a) indicating a position Y on the image including the position Y ₁ on the image the position Y corrected by the first boundary edge 15a borderline position Y corresponding to _E15a (theta) relative to the It is a figure (b) shown. The edge line E _{23 of} the third film layer image, the edge line E ₂₂ of the second film layer image, the boundary line E _15b corresponding to the second boundary edge 15b of the semiconductor wafer, and the third boundary obtained by the second camera unit A diagram (a) showing a position Y on an image including a boundary line E _15c corresponding to the edge 15c, and a position Y _E15b (θ) corresponding to the position Y corresponding to the second boundary edge 15b. FIG. 6B is a diagram (b) showing a position Y ₂ on the corrected image. The edge line E _{22 of} the second film layer image, the edge line E ₂₁ of the first film layer image, the boundary line E _15c corresponding to the third boundary edge 15c of the semiconductor wafer, and the fourth boundary obtained by the third camera unit A diagram (a) showing the position Y on the image including the boundary line E _15d corresponding to the edge 15d, and the position Y as a reference based on the boundary line position Y _E15c (θ) corresponding to the third boundary edge 15c. FIG. 6B is a diagram (b) showing a position Y ₃ on the corrected image. FIG. 5A shows a position Y on an image including a boundary line E _15d obtained by the fifth camera unit and corresponding to the fourth boundary edge 15d of the semiconductor wafer, and shows the position Y as the fourth boundary edge. FIG. 10B is a diagram (b) showing a correction position Y ₅ on the image corrected with reference to the boundary line position Y _E15d (θ) corresponding to 15d. It is a figure which shows the synthesized image obtained by synthesize | combining the five images obtained by five camera units of a 1st camera unit-a 5th camera unit. They are the perspective view (a) which shows the external appearance of a semiconductor wafer, and sectional drawing (b) which expanded and showed the AA cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor wafer 10E Outer peripheral part 11a Upper surface 11b Lower surface 12U Upper outer peripheral bevel surface 12A Outer peripheral end surface 12L Lower outer peripheral bevel surface 15a First boundary edge 15b Second boundary edge 15c Third boundary edge 15d Fourth boundary edge 20 Film layer 21 1st film layer 22 2nd film layer 23 3rd film layer 24 4th film layer 100 Stage 110 Rotation drive motor 130a 1st camera unit 130b 2nd camera unit 130c 3rd camera unit 130d 4th camera unit 130e 5th camera Unit 200 Processing unit 210 Operation unit 220 Display unit

Claims (4)

A plurality of surfaces that are continuous in a direction crossing the circumferential direction in the outer peripheral portion of the disk-shaped substrate are included in the respective photographing field-of-view ranges, and the plurality of surfaces are sequentially photographed in the circumferential direction of the disk-shaped substrate to output an image signal. A shooting section;
An image processing unit that processes image signals sequentially output from the photographing unit;
The image processing unit
Based on the image signal, image data generating means for generating photographic image data representing a photographic image corresponding to each photographing visual field range including each of the plurality of surfaces extending corresponding to the circumferential direction of the disc-shaped substrate;
From photographed image data representing a photographed image corresponding to each photographing field range including each of the plurality of surfaces, a plurality of surface image portions corresponding to the plurality of surfaces are joined so as to match their corresponding boundary lines. Image synthesizing means for generating synthesized image data representing the synthesized image,
It possesses an output control means for displaying on the display unit of the composite image based on the composite image data,
The image synthesizing unit includes a boundary line between a surface image portion corresponding to the surface on a captured image corresponding to each photographing field range including each of the plurality of surfaces and an outer image portion on one surface side adjacent to the surface. The vertical position of each pixel point at the corresponding position in the circumferential direction is represented on the basis of the vertical position representing the position in the direction across the circumferential direction at each position in the circumferential direction. Correction means for correcting captured image data representing a captured image;
On the photographic image corresponding to the photographic field range including the predetermined plane of the plurality of surfaces, from the corrected photographic image data representing the photographic field range corresponding to each photographic field range including each of the plurality of surfaces. The combination in which the boundary line is a reference boundary line, and the vertical position of each pixel point at the corresponding position in the circumferential direction is determined with reference to the vertical position at each position in the circumferential direction of the reference boundary line An inspection apparatus for a disk-shaped substrate, comprising: composite image data generating means for generating composite image data representing an image. The disc-shaped substrate includes an upper outer peripheral bevel surface inclined from the edge of the upper surface toward the lower surface, an outer peripheral end surface continuing from the edge of the upper outer peripheral bevel surface, and a lower surface continuing from the lower surface toward the upper surface and continuing to the outer peripheral end surface. The outer peripheral bevel surface is a semiconductor wafer formed so as to be continuous in a direction crossing the circumferential direction,
The plurality of surfaces are continuous in an adjacent region of the upper surface with the upper outer peripheral bevel surface, the upper outer peripheral bevel surface, an outer peripheral end surface, a lower outer peripheral bevel surface, and a lower surface adjacent to the lower outer peripheral bevel surface. The disk-shaped substrate inspection device according to claim 1 , wherein the inspection device has two or more surfaces. The plurality of surfaces are the upper outer peripheral bevel surface, the outer peripheral end surface, and the lower outer peripheral bevel surface,
The image data generating means is configured to generate a first captured image corresponding to a field of view of view including the upper and outer peripheral bevel surfaces extending corresponding to a circumferential direction of the semiconductor wafer based on image signals sequentially output from the imaging unit. First photographed image data representing, second photographed image data representing a second photographed image corresponding to the photographing field range including the outer peripheral end surface, and a third photographed image corresponding to the photographing field range including the lower outer peripheral bevel surface. To generate third captured image data representing,
The image synthesizing means is a vertical direction at each position in the circumferential direction of a boundary line between an upper outer peripheral bevel surface image portion corresponding to the upper outer peripheral bevel surface on the first photographed image and an outer image portion on the upper surface side thereof. Correcting the first captured image data so that a vertical position at a position corresponding to the circumferential direction of each pixel point on the first captured image is represented on the basis of the position;
Based on the vertical position at each position in the circumferential direction of the boundary line between the outer peripheral end surface image portion corresponding to the outer peripheral end surface on the second photographed image and the outer image portion on the upper outer peripheral bevel surface side, Correcting the second captured image data so that a vertical position at a position corresponding to the circumferential direction of each pixel point on the second captured image is represented;
On the basis of the vertical position at each position in the circumferential direction of the boundary line between the lower outer peripheral bevel surface image portion corresponding to the lower outer peripheral bevel surface and the outer image portion on the outer peripheral end surface side on the third photographed image. , Correcting the third photographed image data so that a vertical position at a position corresponding to the circumferential direction of each pixel point on the third photographed image is represented,
From the corrected first photographed image data, second photographed image data, and third photographed image data, the upper outer peripheral bevel surface image portion, the outer peripheral end surface image portion, and the lower outer peripheral bevel surface image portion have their corresponding boundaries. A combined image joined so as to match lines, with the boundary line on the first photographed image as a reference boundary line, and the vertical position at each position in the circumferential direction of the reference boundary line as a reference The disk-shaped substrate inspection apparatus according to claim 2 , wherein composite image data representing the composite image in which a vertical position at a position corresponding to the circumferential direction of each pixel point is determined is generated. The plurality of surfaces include a region adjacent to the upper outer peripheral bevel surface of the upper surface of the semiconductor wafer, the upper outer peripheral bevel surface, an outer peripheral end surface, a lower outer peripheral bevel surface, and the lower outer peripheral bevel surface of the lower surface of the semiconductor wafer. Adjacent area,
The image data generating means is configured to generate a first captured image corresponding to a field of view of view including the upper and outer peripheral bevel surfaces extending corresponding to a circumferential direction of the semiconductor wafer based on image signals sequentially output from the imaging unit. First photographed image data representing, second photographed image data representing a second photographed image corresponding to the photographing field range including the outer peripheral end surface, and a third photographed image corresponding to the photographing field range including the lower outer peripheral bevel surface. Fourth photographed image data representing a fourth photographed image corresponding to a photographing field range including a region adjacent to the upper and outer peripheral bevel surfaces of the upper surface and the lower outer peripheral bevel surface of the lower surface Generating fifth photographed image data representing a fifth photographed image corresponding to a photographing field range including an adjacent region;
The image synthesizing means is a vertical direction at each position in the circumferential direction of a boundary line between an upper outer peripheral bevel surface image portion corresponding to the upper outer peripheral bevel surface on the first photographed image and an outer image portion on the upper surface side thereof. Correcting the first captured image data so that a vertical position at a position corresponding to the circumferential direction of each pixel point on the first captured image is represented on the basis of the position;
Based on the vertical position at each position in the circumferential direction of the boundary line between the outer peripheral end surface image portion corresponding to the outer peripheral end surface on the second photographed image and the outer image portion on the upper outer peripheral bevel surface side, Correcting the second captured image data so that a vertical position at a position corresponding to the circumferential direction of each pixel point on the second captured image is represented;
On the basis of the vertical position at each position in the circumferential direction of the boundary line between the lower outer peripheral bevel surface image portion corresponding to the lower outer peripheral bevel surface and the outer image portion on the outer peripheral end surface side on the third photographed image. , Correcting the third photographed image data so that a vertical position at a position corresponding to the circumferential direction of each pixel point on the third photographed image is represented,
A vertical line at each position in the circumferential direction of a boundary line between an upper surface image portion corresponding to a region adjacent to the upper outer peripheral bevel surface on the upper surface on the fourth photographed image and an outer image portion on the upper outer peripheral bevel surface side. Correcting the fourth captured image data so that the vertical position at the position corresponding to the circumferential direction of each pixel point on the fourth captured image is represented with respect to the direction position;
At each position in the circumferential direction of a boundary line between a lower surface image portion corresponding to a region adjacent to the lower outer peripheral bevel surface of the lower surface on the fifth photographed image and an outer image portion adjacent to the lower outer peripheral bevel surface side. The fifth captured image data is corrected so that the vertical position at the corresponding position in the circumferential direction of each pixel point on the fifth captured image is represented with respect to the vertical position of
From the corrected first photographed image data, second photographed image data, third photographed image data, fourth photographed image data, and fifth photographed image data, the upper surface image portion, the upper outer periphery bevel surface image portion, and the outer periphery A composite image obtained by joining an end face image portion, the lower outer peripheral bevel surface image portion, and the lower surface image portion so that their corresponding boundary lines are matched, and the boundary line on the first photographed image is used as a reference Composite image data representing the composite image in which the vertical position at the corresponding position in the circumferential direction of each pixel point is determined with reference to the vertical position at each position in the circumferential direction of the reference boundary line as a boundary line The disk-shaped substrate inspection apparatus according to claim 2, wherein:

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