TWI726977B - Defect inspection device - Google Patents

Abstract

The present invention provides a defect inspection device capable of suppressing missed inspections of defects or false inspections of defects. The defect inspection apparatus 100 includes a control unit 50 based on the image of the element wafer 70 captured by the imaging unit 40, and detects the edge 74 and the effective area 71 outside the peripheral area 72 of the element wafer 70, based on the The edge 74 and the effective area 71 outside the peripheral area 72 are detected to determine the inspection area 75 used to inspect the defect of the component wafer 70, and the corresponding image of the inspection area 75 of the component wafer 70 is stored in advance. The images of the device wafer 70 are compared to detect defects of the device wafer 70.

Description

Defect inspection device

The present invention relates to a defect inspection device, and more particularly, to a defect inspection device including a defect detection section that detects defects of the device chip by comparing with the image of the good device chip.

Previously, there has been known a defect inspection device including a defect detection section that detects defects of an element wafer by comparing with an image of a good element wafer (for example, refer to Patent Document 1).

A defect inspection method is disclosed in the aforementioned Patent Document 1. The defect inspection method calculates the difference between the standard image and the inspection image, and then inspects the workpiece for defects based on the difference between the standard image and the inspection image. In this inspection method, multiple good-quality workpieces are photographed during the teaching process, and the average value of the shade value of each pixel of the image (standard image) is obtained. In addition, during the inspection process, the workpiece to be inspected is photographed. Furthermore, when photographing the workpiece of the inspection target, the same part as the workpiece of the good product that has been photographed is photographed as the inspection image. Then, based on the comparison between the standard image of the workpiece of the good product and the inspection image of the workpiece of the inspection target, the presence or absence of defects is determined.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 10-123064

However, in the defect inspection method described in Patent Document 1, the inspection object is photographed In the case of the workpiece, the part (hereinafter referred to as the effective area) that is the same as the workpiece that has been photographed is taken as the inspection image. That is, the part (effective area) of the workpiece of the inspection object being photographed corresponds to the standard image and is fixed. Therefore, there is a disadvantage that it is impossible to detect defects generated outside the effective area of the workpiece. Furthermore, as for the defects generated outside the effective area of the workpiece, there is a situation in which the defect develops (increases), which will adversely affect the function of the workpiece in the future. In addition, there is the following disadvantage: Although it does not contain defects, when the end of the workpiece to be inspected is cut, based on the difference between the image of the cut end located in the effective area and the standard image, Misrecognition is a defect in the inspection object. That is, in the defect inspection method described in the above-mentioned Patent Document 1, there is a problem of missed inspection of defects or false inspection of defects.

The present invention was completed in order to solve the above-mentioned problems, and one of the objectives of the present invention is to provide a defect inspection device that can suppress the missed inspection of defects or the false inspection of defects.

In order to achieve the above-mentioned object, a defect inspection device of one aspect of the present invention includes: an imaging section that photographs an element wafer including an effective area formed with elements and a peripheral area provided on the periphery of the effective area; an edge detection section, It is based on the image of the element wafer taken by the imaging unit to detect the edge outside the peripheral area of the component wafer; the effective area detection unit, which is based on the image of the component wafer taken by the imaging unit, detects the effective area of the element wafer ; The inspection area determination section, which determines the inspection area for inspecting the defect of the component chip based on the edge and the effective area outside the detected peripheral area; and the defect detection section, which corresponds to the inspection area of the component wafer The image is compared with the image of the component chip of the good product stored in advance, and the defect of the component chip is detected.

In the defect inspection device of one aspect of the present invention, as described above, an inspection area determining unit is included, which determines the inspection area based on the edge and the effective area outside the detected peripheral area. The inspection area for checking component wafer defects. Thereby, the inspection area can be changed correspondingly to the outer edge (the size of the element wafer) of the peripheral area of the element wafer. Therefore, unlike when the inspection area is fixed, it is possible to suppress missed inspection of defects. In addition, by changing the inspection area corresponding to the size of the element wafer, even when the end of the element wafer is cut, the cut portion becomes outside the inspection area. Thereby, it is possible to suppress the false detection of defects caused by the difference between the image of the device chip after the end portion is cut off and the image of the good device chip memorized in advance. In this way, it is possible to suppress missed inspections of defects or false inspections of defects.

In the defect inspection apparatus of the above aspect, it is preferable that: the image of the good component wafer is the image of the part corresponding to one component wafer of the component wafer before cutting before cutting; The chip includes a plurality of effective areas and a cut area provided between the plurality of effective areas and including the peripheral area. The one device wafer includes at least the peripheral area in both the effective area and the peripheral area. Here, when the inspection area is changed to correspond to the edge (the size of the element wafer) outside the peripheral area of the element wafer, when using the image of the cut element wafer as the image of the good element wafer , There are cases where the size of the inspection area (the size of the component wafer to be inspected) is different from the size of the component wafer after cutting. In this case, even if the corresponding image of the inspection area of the component wafer to be inspected is compared with the image of the good component wafer after cutting, it is difficult to accurately determine the presence or absence of defects. Therefore, as described above, the image of the part of the element chip before cutting before cutting that corresponds to one element chip including at least the peripheral area of the effective area and the peripheral area is used as the image of the good element wafer , The image of the component wafer before cutting corresponding to the size of the inspection area of the component wafer to be inspected can be used as the image of the good component wafer. As a result, it is possible to accurately determine the presence or absence of defects.

Also, when using the image of the device chip after cutting as the image of the good device chip In this case, there are cases where the device wafer after cutting contains defects. In addition, when cutting the element wafer before cutting, the cutting position of the element wafer may be deviated due to the accuracy of the cutting device (die cutting device, etc.). That is, in the case of using the image of the cut element wafer as the image of the good element wafer, there may be cases in which the image of the good product to be compared with the element wafer to be inspected is not suitable. Therefore, by using the image of the device chip before cutting as the image of the good device chip, it is possible to easily obtain an appropriate good product image.

In the defect inspection device of the above aspect, it is preferable to further include: a defect type judging section that judges the type of defect based on the shape of the detected defect; and a good product judging section based on the defect type judging section The type of the identified defect and the position of the defect relative to the effective area are determined to determine whether the device chip is a good product or a defective product. Here, even when there is a defect, the device chip is regarded as a good product. Therefore, by determining whether the device chip is a good product or a defective product based on the type of the defect and the position of the defect relative to the effective area, it is possible to prevent a good device chip from being judged as a defective product only because of the defect.

In this case, it is preferable to be configured as follows: when the defect type determination section determines that the defect is a defect of the device chip based on the shape of the defect, the good product determination section determines the device chip when the defect reaches the effective area It is a defective product. If the defect does not reach the effective area, the device chip will be judged as a good product. Here, the possibility that the defect will become larger in the future (the defect will gradually develop from the peripheral area to the effective area) is relatively small. Therefore, by determining the device chip as a good product if the defect does not reach the effective area, it is possible to prevent a good device chip from being determined as a defective product only because of the defect.

In the defect inspection apparatus including the above-mentioned defect type discrimination section, it is preferable to be configured as follows: when the defect type discrimination section determines that the defect is a crack of the element chip based on the shape of the defect, the good product determination section does not matter whether the defect is cracked Whether it reaches the effective area, the component chip is judged as Defective product. Here, the possibility that the cracks will become larger in the future (cracks will gradually develop from the peripheral area to the effective area) is relatively high. Therefore, by determining the device chip as a defective product regardless of whether the crack reaches the effective area or not, it is possible to eliminate in advance the device chip that is currently a good product but will become a defective product in the future.

According to the present invention, as described above, it is possible to suppress missed detection of defects or erroneous detection of defects.

10: mobile station

11: X-axis slider

12: Y-axis slider

20: Desk

30: Mounting table

40: Camera Department

41: lens barrel

42: half mirror

43: Objective

44: Camera

44a: Light receiving element

50: Control unit (edge detection unit, effective area detection unit, inspection area determination unit, defect detection unit, defect type discrimination unit, good product judgment unit)

60: Memory Department

70: Component chip

70a: Component wafer

70b: Component chip

70c: Component chip

70d: component chip

71: effective area

72: Peripheral area

72a: The part arranged on the Y1 direction side of the effective area

72b: The part arranged on the Y2 direction side of the effective area

72c: The part arranged on the Y1 direction side of the effective area

72d: The part arranged on the Y2 direction side of the effective area

73: Cut off area

74: Edge

75: Check the area

75a: Inspection area

80: Taiwan

81: sheet member

82: Substrate (wafer)

83: Cutting off the front component wafer

90: Defect

90a: Defect

90b: cracked

100: Defect inspection device

171: effective area

172: Peripheral area

175: Check the area

C: Cut the line

W1: width

W2: width

W3: width

W4: width

W5: width

Fig. 1 is an overall view of a defect inspection device according to an embodiment of the present invention.

Fig. 2 is a diagram for explaining the operation of the imaging unit of the defect inspection device in one embodiment of the present invention.

Fig. 3 is a diagram showing the element wafer before cutting.

Fig. 4 is a partial enlarged view of Fig. 3 (a diagram showing a good component chip).

Fig. 5 is a diagram showing the device wafer after cutting.

Fig. 6 is a flow chart for explaining the operation before inspection of the defect inspection device in one embodiment of the present invention.

FIG. 7 is a flow chart for explaining the preparation of the production of the image of the component chip of the good product.

Fig. 8 is a flow chart for explaining the production of the image of the component chip of the good product.

FIG. 9 is a flowchart for explaining the operation of the defect inspection device in one embodiment of the present invention during inspection.

FIG. 10 is a flowchart for explaining the inspection of the component wafer as the inspection object.

Figure 11 is a flow chart for explaining the inspection of the peripheral area.

Fig. 12 is a diagram showing an inspection area of a modified example of this embodiment.

Hereinafter, an embodiment embodying the present invention will be described based on the drawings.

[This embodiment]

(Structure of defect inspection device)

1 and 2, the structure of the defect inspection apparatus 100 of this embodiment will be described.

As shown in FIG. 1, the defect inspection apparatus 100 includes a mobile station 10. The mobile station 10 includes an X-axis slider 11 and a Y-axis slider 12. The X-axis slider 11 is arranged on the table portion 20. In addition, the Y-axis slider 12 is arranged on the X-axis slider 11.

In addition, the defect inspection apparatus 100 includes a mounting table 30. The mounting table 30 is arranged on the Y-axis slider 12. In addition, the mounting table 30 is configured to move in the X direction and the Y direction by the moving table 10. In addition, the mounting table 30 is configured to mount the element wafer 83 before cutting (see FIG. 4) or the element wafer 70 after cutting (see FIG. 5).

In addition, the defect inspection apparatus 100 includes an imaging unit 40. The imaging unit 40 is configured to image the element wafer 70 (refer to FIGS. 4 and 5) including the effective area 71 in which the elements are formed and the peripheral area 72 provided on the periphery of the effective area 71. The imaging unit 40 includes a lens barrel 41, a half mirror 42, an objective lens 43, and a camera 44. The camera 44 includes a light receiving element 44a. In addition, the camera 44 is configured to output an image of the element wafer 70 obtained by shooting to the control unit 50 described below.

In addition, as shown in FIG. 2, the imaging unit 40 is configured to sequentially image a plurality of element wafers 70 that move relative to the imaging unit 40. Specifically, the element wafer 70 is moved relative to the imaging unit 40 by the moving stage 10.

Moreover, as shown in FIG. 1, the defect inspection apparatus 100 includes a control unit 50. Here, in this embodiment, the control unit 50 is configured as follows: the corresponding image (refer to FIG. 5) of the inspection area 75 of the component wafer 70 and the image of the good component wafer 70 (refer to the figure) stored in advance 4) Comparing, thereby detecting the defect 90 of the element wafer 70, and determining whether the element wafer 70 is good or not Defective product. Furthermore, the detailed operation of the control unit 50 will be described below.

In addition, the defect inspection apparatus 100 includes a storage unit 60. The image of the defective device chip 70 is stored in the memory portion 60.

(Method of manufacturing component chip)

3 and 4, the manufacturing method of the element wafer 70 will be described.

First, as shown in FIG. 3, a flexible film-like sheet member 81 is arranged on the surface of the table portion 80 including SUS or the like. Then, a substrate (wafer) 82 is placed on the surface of the sheet member 81. Furthermore, by forming an element including a semiconductor or the like on the surface of the substrate (wafer) 82, an element wafer 83 before cutting is formed.

Furthermore, as shown in FIG. 4, the element is formed in a specific area (effective area 71) on the surface of the substrate 81. A plurality of effective areas 71 are provided, and they are arranged in a matrix shape. In addition, between the plurality of effective regions 71 are regions where no element is formed (peripheral region 72, cut-off region 73). In addition, the effective area 71 has a substantially rectangular shape.

Then, the substrate 81 is cut along the cutting line (scribing line) C passing through the approximate center of the adjacent effective region 71 (the approximate center of the cutting region 73) (die cutting step). Thereby, as shown in FIG. 5, the element wafer 70 (70a-70d) is formed.

In the element wafer 70a (refer to the upper left of FIG. 5), an effective area 71 in which elements are formed is arranged in the center portion. In addition, a peripheral area 72 is arranged on the periphery (outer periphery) of the effective area 71. The peripheral area 72 is the part of the device wafer 70 excluding the effective area 71. In addition, the peripheral region 72 is a portion that is not cut but remains in the cut region 73 cut (cut off) by the dicing step. Furthermore, the element wafer 70 (outside the peripheral area 72) has a substantially rectangular shape.

In addition, in the dicing step, the substrate 81 is cut by a dicing knife or the like, so there are cases where a defect 90 is generated in the peripheral region 72 like the element wafer 70b (see the lower left in FIG. 5). For example, produce Health defect 90a (nick), and crack 90b (crack). Furthermore, in the device wafer 70b, the defect 90a and the crack 90b shown by the solid line represent an example of not reaching the effective area 71. In addition, the defect 90a shown by the broken line represents an example of reaching the effective area 71.

In addition, although the substrate 81 is cut along the cutting line C, the cutting position of the element wafer 70 may deviate due to the accuracy of the dicing device. Therefore, there are cases in which the widths of the peripheral regions 72 provided along the sides of the substantially rectangular effective region 71 are different from each other. For example, in the element wafer 70c (refer to the upper right of FIG. 5), the portion 72b of the peripheral region 72 arranged on the Y2 direction side of the effective area 71 has a width W2 along the Y direction larger than that of the effective area 71 on the Y1 direction side The width W1 of the portion 72a along the Y direction. That is, the width W2 is larger than the width W3 of the peripheral region 72 that is accurately cut (refer to the element wafer 70a, the upper left of FIG. 5). In addition, in the element wafer 70c, an example in which a defect 90a and a crack 90b are generated in the peripheral region 72 is shown. In addition, the defect 90a and the crack 90b of the element wafer 70c do not reach the effective area 71.

In addition, in the element wafer 70d (refer to the lower right of FIG. 5), the width W4 along the Y direction of the portion 72c arranged on the Y1 direction side of the effective area 71 in the peripheral region 72 is smaller than the Y2 direction side arranged on the effective area 71 The width W5 of the portion 72d along the Y direction. That is, the width W4 is smaller than the width W3 of the peripheral region 72 that is accurately cut (refer to the element wafer 70a, the upper left of FIG. 5).

Then, after the dicing step, the sheet member 81 is expanded, thereby expanding the interval between the element wafers 70 (expansion step).

(Image of good product component chip)

Next, referring to FIG. 4, an image of a good component wafer 70 to be compared with the component wafer 70 to be inspected will be described.

Here, in this embodiment, the image of the defective element wafer 70 is the image of the part corresponding to one element wafer 70 of the element wafer 83 before cutting before cutting (the thick dashed line in FIG. 4 encloses The image of the surrounding element wafer 70); the above-mentioned element wafer 83 before cutting includes a plurality of effective areas 71, and a cutting area 73 disposed between the plurality of effective areas 71 and including the peripheral area 72, the above-mentioned one element wafer 70 includes at least a peripheral area 72 in both the effective area 71 and the peripheral area 72 (in this embodiment, both the effective area 71 and the peripheral area 72 are included). That is, the image of the good device wafer 70 is the image of the device wafer 83 before cutting before the dicing step. Specifically, the element wafer 83 before cutting includes a plurality of effective regions 71 and a cutting region 73 (peripheral region 72) between the effective regions 71. In addition, the image of the good component wafer 70 is the part corresponding to one component wafer 70 including one effective area 71 and a cut area 73 (cutting area 73 having a width W5) surrounding the effective area 71 Of the image. That is, the peripheral area 72 of the image of the good device chip 70 is an area from the effective area 71 included in the image of the good device chip 70 to the adjacent effective area 71. That is, the peripheral area 72 of the image of the good device wafer 70 is the largest width among the widths that the peripheral area 72 can reach.

(Action before inspection of defect inspection device)

Next, referring to FIGS. 6 to 8, the operation before the inspection of the defect inspection device 100 (control section 50) will be described.

<Transfer of Component Wafer Before Cutting>

First, as shown in FIG. 6, in step S1, the element wafer 83 before cutting is transported from a specific position to the mounting table 30 of the defect inspection apparatus 100 (refer to FIG. 1).

<Global alignment>

Then, in step S2, the global alignment of the element wafer 83 before cutting is performed. That is, the angle and center position of the element wafer 83 before cutting are determined.

<Preparation for the production of the image of the component chip of the good product>

Then, in step S3, an image of the defective device wafer 70 is produced. Specific and In other words, as shown in FIG. 7, in step S31, the imaging unit 40 images the entire element wafer 83 before cutting. Then, in step S32, the effective area 71 of the image of the entire element wafer 83 before cutting is set.

Then, in step S33, an entry prohibited area is set. Furthermore, the so-called forbidden area is an area that is approximately the same as the effective area 71, and is an area where the defect 90 must not be allowed to enter. That is, the device wafer 70 with the defect 90 intruding into the forbidden area is a defective product.

Then, in step S34, the peripheral region 72 (cutting region 73) is set.

Then, in step S35, an alignment mark for detecting the effective area 71 (no entry area), the components in the effective area 71, and the like is set. Then, in step S36, the parameters for detecting the edge 74 outside the peripheral region 72 and other parameters are set and saved.

<Production of the image of the component chip of the good product>

Then, as shown in FIG. 6, in step S4, an image of a good device wafer 70 is produced. Specifically, as shown in FIG. 8, in step S41, various parameters are called.

Then, in step S42, the imaging unit 40 is moved to above the target element wafer 70 (effective area 71, peripheral area 72) in the element wafer 83 before cutting. Then, in step S43, the target element wafer 70 (effective area 71, peripheral area 72) is photographed.

Then, in step S44, the effective area 71 and the peripheral area 72 are aligned based on the alignment marks of the components and the like in the registered effective area 71. Specifically, after the effective area 71 is detected based on the alignment mark, the peripheral area 72 is detected based on the coordinates of the detected effective area 71 (refer to the peripheral area having the width W5, FIG. 4). Then, in step S45, the image of the effective area 71 is stored in the storage unit 60. In addition, in step S46, the image of the peripheral region 72 is stored in the memory unit 60. Furthermore, steps S42 to S46 are repeated as many times as the number of target device wafers 70 (effective area 71, peripheral area 72).

Then, in step S47, an image of the effective area 71 of the good product is produced. Specifically, the brightness of each pixel of each of the plurality of memorized images of the effective area 71 in steps S42 to S46 is averaged. Then, an image of the effective area 71 of the good product is produced by pixels composed of average brightness.

Then, in step S48, an image of the peripheral area 72 of the good product is produced. Specifically, the brightness of each pixel of each of the images of the plurality of peripheral regions 72 memorized in steps S42 to S46 is averaged. Then, an image of the peripheral area 72 of the good product is produced by pixels composed of average brightness.

Then, in step S49, the image of the effective area 71 of the good product and the image of the peripheral area 72 of the good product are stored in the memory 60 as the image of the device chip 70 of the good product.

Then, as shown in FIG. 6, in step S5, the element wafer 83 before cutting is accommodated in a specific position.

(Action during inspection of defect inspection device)

Next, referring to FIGS. 9 to 11, the operation of the defect inspection apparatus 100 (control section 50) during inspection will be described. Furthermore, the control unit 50 is one of the "edge detection unit", "effective area detection unit", "inspection area determination unit", "defect detection unit", "defect type discrimination unit", and "good product determination unit" in the scope of the patent application. An example.

<Transfer of Component Wafer>

First, as shown in FIG. 9, in step S11, the component wafer 70 (the component wafer 70 after the dicing step or the expansion step) to be inspected is transported from a specific position to the mounting table 30 of the defect inspection apparatus 100 (Refer to Figure 1).

<Global alignment>

Then, in step S12, the global alignment of the device wafer 70 is performed. That is, determine the element crystal The angle and center position of the sheet 70.

<Inspection of Component Chip>

Then, in step S13, the device wafer 70 is inspected. Specifically, as shown in FIG. 10, in step S131, various parameters are called.

Then, in step S132, the image of the effective area 71 of the good product is read. Furthermore, in step S133, the image of the peripheral area 72 of the good product is read.

Then, in step S134, the imaging unit 40 is moved above the element wafer 70 to be inspected. Then, in step S135, the device wafer 70 to be inspected is photographed by the imaging unit 40.

Then, in step S136, the effective area 71 of the element wafer 70 to be inspected is aligned based on the alignment mark of the element or the like in the registered effective area 71. That is, in this embodiment, the peripheral area 72 and the effective area 71 are used as the inspection area 75 for inspecting the defect of the element wafer 70.

Then, in step S137, the effective area 71 is checked. Specifically, the brightness of each pixel of the image of the effective area 71 of the good product is compared with the brightness of each pixel of the image of the effective area 71 of the element wafer 70 to be inspected.

Then, in step S138, the peripheral region 72 is inspected. Specifically, as shown in FIG. 11, in the present embodiment, in step S141, based on the image of the element wafer 70 captured by the imaging unit 40, the edge 74 outside the peripheral region 72 of the element wafer 70 is detected ( Refer to Figure 5). Specifically, find the brightness of each pixel of the image. Then, in the pixel, the brightness is scanned along the X direction (and the Y direction), and the vicinity of the pixel whose brightness changes rapidly is detected as the edge 74 outside the peripheral area 72 of the element wafer 70.

Then, in step S142, the noise of the edge 74 detected in step S141 is removed. Specifically, in the device wafer 70 after the dicing step, a defect 90a or a crack 90b may be generated near the edge 74. In this case, the detected edge 74 does not become a straight line at the defect 90a or crack 90b. Therefore, the part of the defect 90a or the crack 90b is removed from the data of the edge 74. Then, in step S143, based on the data of the edge 74 after the noise is removed, the edge 74 is detected again so that the edge 74 becomes a substantially linear shape.

Then, in this embodiment, the inspection area 75 for inspecting the defect of the element wafer 70 is determined based on the edge 74 and the effective area 71 outside the peripheral area 72 that are detected. For example, pixels that are 2 or 3 pixels inward from the edge 74 outside the peripheral region 72 of the element wafer 70 detected among the pixels are determined as the inspection region 75 (see FIG. 5).

By thus determining the inspection area 75 based on the edge 74 outside the peripheral area 72 of the element wafer 70, the width W2 of the portion 72b of the peripheral area 72 of the element wafer 70c as shown in FIG. 5 (refer to the upper right) In the larger case, substantially the entire area of the element wafer 70c also becomes the inspection area 75. That is, as in the case where the inspection area 75a is fixed (refer to the dashed line in FIG. 5), the end of the portion 72b of the peripheral area 72 on the Y2 direction side is suppressed from being outside the inspection area 75. That is, the parts of the defect 90a and the crack 90b also become the inspection area 75.

Moreover, even when the width W4 of the portion 72c of the peripheral area 72 of the element wafer 70d as shown in FIG. 5 (see the lower right) is small, the substantially entire area of the element wafer 70d becomes the inspection area 75. That is, as in the case where the inspection area 75a is fixed (refer to the dashed line in FIG. 5), the portion beyond the Y1 direction side end (edge 74) of the portion 72c of the peripheral area 72 is suppressed from being included in the inspection area 75.

Then, in step S144, the defect 90 is detected. Specifically, the brightness of each pixel of the image of the peripheral region 72 of the good product is compared with the brightness of each pixel of the image of the peripheral region 72 of the element wafer 70 to be inspected. Then, the defect of the element chip 70 is detected Trapped 90. For example, calculate the difference between the brightness of each pixel of the image of the peripheral area 72 of the good product and the brightness of each pixel of the image of the device wafer 70 to be inspected, and if the difference (absolute value) is greater than a certain threshold, it is determined For defect 90. Furthermore, the position (coordinates) of the defect 90 is also detected.

Here, the size of the image of the defective element wafer 70 and the image of the element wafer 70 to be inspected may be different from each other. On the other hand, in the image of the defective element wafer 70 and the image of the element wafer 70 to be inspected, the size of the effective area 71 of the two is approximately the same. That is, the peripheral regions 72 are different from each other. Therefore, in the image of the component wafer 70 to be inspected, the size (range) of the peripheral area 72 is detected based on the effective area 71, and a good component wafer 70 is determined in a manner corresponding to the size (range) The size (range) of the peripheral area 72 in the image. Thereby, it is possible to make the size of the image of the good component wafer 70 correspond to the size of the image of the component wafer 70 to be inspected.

Then, in step S145, it is determined whether the detected defect 90 has entered the no-entry area (effective area 71). Furthermore, it is determined whether the detected defect 90 involves the edge 74 (whether it extends from the edge 74).

Then, in step S146, the type of the defect 90 is determined based on the shape (length, aspect ratio, area, brightness, etc.) of the detected defect 90. For example, based on the shape of the detected defect 90, it is judged whether it is a defect 90a or whether it is a crack 90b.

Here, in the present embodiment, when it is determined that the defect 90 is the defect 90a of the device chip 70, if the defect 90a (the defect 90a extending from the edge 74) reaches the effective area 71 (the device chip 70b at the bottom left of FIG. 5) If the defect 90a) is shown by the dotted line, the device chip 70 is judged to be defective. On the other hand, if the defect 90a does not reach the effective area 71 (the defect 90a shown by the solid line of the element wafer 70b at the bottom left of FIG. 5, and the defect 90a of the element wafer 70c at the upper right of FIG. 5), the element wafer 70 is judged to be Good product. The reason is that the defect 90a that does not reach the effective area 71 will develop to the effective area 71 in the future. It is less likely.

Furthermore, in this embodiment, when it is determined that the defect 90 is the crack 90b of the element wafer 70, whether the crack 90b (crack 90b extending from the edge 74) reaches the effective area 71, it is determined that the element wafer 70 It is a defective product. That is, the element wafer 70b at the lower left in FIG. 5 and the element wafer 70c at the upper right in FIG. 5 were determined to be defective due to the occurrence of a crack 90b. The reason is that although the crack 90b does not reach the effective area 71, the possibility of the crack 90b developing to the effective area 71 in the future is higher.

In addition, although the part 72c of the peripheral region 72 on the Y1 direction side of the element wafer 70d in the lower right of FIG. 5 was cut so that the width W4 was reduced, the defect 90 did not occur, so it was judged to be a good product.

Furthermore, when the defect 90 does not extend from the edge 74, it is determined that the device wafer 70 is a good product. That is, the defect 90 is discriminated as a foreign matter on the element wafer 70.

Furthermore, steps S134 to S138 are repeated as many times as the number of element wafers 70 to be inspected. Then, in step S139, the inspection result is stored in the storage unit 60.

Finally, as shown in FIG. 9, in step S15, the element wafer 70 is stored in a specific position.

(Effects of this embodiment)

Next, the effect of this embodiment will be explained.

In this embodiment, as described above, the control unit 50 includes the control unit 50 that determines the inspection area 75 for inspecting the defect 90 of the element wafer 70 based on the edge 74 and the effective area 71 outside the peripheral area 72 that are detected. Thereby, the inspection area 75 can be changed correspondingly to the edge 74 (the size of the element wafer 70) outside the peripheral area 72 of the element wafer 70. Therefore, unlike the case where the inspection area 75 is fixed, the leakage of the defect 90 can be suppressed. Check. Furthermore, by changing the inspection area 75 corresponding to the size of the element wafer 70, even when the end of the element wafer 70 is cut, the cut portion becomes outside the inspection area 75. In this way, it is possible to prevent the end portion from being cut The image of the device chip 70 is different from the image of the good device chip 70 memorized in advance, which causes the defect 90 to be misdetected. In this way, the missed detection of the defect 90 or the false detection of the defect 90 can be suppressed.

In addition, in this embodiment, as described above, the image of the defective element wafer 70 is the image of the part corresponding to one element wafer 70 of the element wafer 83 before cutting before cutting; The element wafer 83 includes a plurality of effective areas 71 and a cut area 73 disposed between the plurality of effective areas 71 and including the peripheral area 72. The above-mentioned one element wafer 70 includes at least both the effective area 71 and the peripheral area 72 The peripheral area 72 (in this embodiment, both the effective area 71 and the peripheral area 72 are included). Here, when the inspection area 75 is changed correspondingly to the edge 74 (the size of the element wafer 70) outside the peripheral area 72 of the element wafer 70, the image of the cut element wafer 70 is used as the good product. In the image of the element wafer 70, the size of the inspection area 75 (the size of the element wafer 70 to be inspected) may be different from the size of the element wafer 70 after cutting. In this case, even if the corresponding image of the inspection area 75 of the element wafer 70 to be inspected is compared with the image of the good element wafer 70 after cutting, it is difficult to accurately determine the presence or absence of the defect 90. Therefore, as described above, the image of the part of the element chip 83 before cutting before cutting that corresponds to one element chip 70 including the effective area 71 and the peripheral area 72 is used as the image of the good element chip 70 Image, the image of the element wafer 83 before cutting (the part corresponding to one element wafer 70 including the effective area 71 and the peripheral area 72) corresponding to the size of the inspection area 75 of the element wafer 70 to be inspected Image) is used as an image of a good device wafer 70. As a result, the presence or absence of the defect 90 can be accurately determined.

In addition, when the image of the cut element wafer 70 is used as the image of the good element wafer 70, there is a case where the cut element wafer 70 contains a defect 90. In addition, when cutting the element wafer 83 before cutting, the cutting position of the element wafer 70 may deviate due to the accuracy of the cutting device (die cutting device, etc.). That is, after using the cut components When the image of the wafer 70 is used as the image of the good component wafer 70, there may be cases where the good product image to be compared with the component wafer 70 to be inspected is not suitable. Therefore, by using the image of the element wafer 83 before cutting as the image of the defective element wafer 70, an appropriate image of the defective product can be easily obtained.

In addition, in this embodiment, as described above, the control unit 50 determines the type of the defect 90 based on the shape of the detected defect 90, and also determines the type of the defect 90 based on the type of the determined defect 90, and the difference between the defect 90 and the effective area 71 , And determine whether the device chip 70 is a good product or a defective product. Here, even when there is a defect 90, the element wafer 70 is regarded as a good product. Therefore, by determining whether the device wafer 70 is a good product or a defective product based on the type of the defect 90 and the position of the defect 90 relative to the effective area 71, it is possible to prevent the defective device wafer 70 from being judged as a defective product only because of the defect 90. The situation.

Furthermore, in this embodiment, as described above, when the control unit 50 determines that the defect 90 is the defect 90a of the element wafer 70 based on the shape of the defect 90, if the defect 90a reaches the effective area 71, the element wafer 70 It is judged to be a defective product, and if the defect 90a does not reach the effective area 71, the element wafer 70 is judged to be a good product. Here, the possibility that the defect 90a becomes larger in the future (the defect 90a gradually develops from the peripheral area 72 to the effective area 71) is relatively small. Therefore, by determining the device wafer 70 as a good product if the defect 90a does not reach the effective area 71, it is possible to prevent the device wafer 70 of a good product from being determined as a defective product only because of the defect 90a.

In addition, in this embodiment, as described above, when the control unit 50 determines that the defect 90 is the crack 90b of the element wafer 70 based on the shape of the defect 90, whether the crack 90b reaches the effective area 71 or not, it will The element wafer 70 is judged to be defective. Here, the possibility that the crack 90b becomes larger in the future (the crack 90b gradually develops from the peripheral area 72 to the effective area 71) is relatively high. Therefore, by determining the element wafer 70 as a defective product regardless of whether the crack 90b reaches the effective area 71 or not, it is possible to The component wafer 70 that is currently a good product but will become a defective product in the future is excluded in advance.

[Change example]

Furthermore, it should be considered that the embodiments and examples disclosed this time are illustrative and not restrictive in all respects. The scope of the present invention is shown not by the description of the above-mentioned embodiments and examples but by the scope of the patent application, and further includes all changes (variations) within the meaning and scope equivalent to the scope of the patent application.

For example, in the above embodiment, the control unit has shown examples of edge detection, effective area detection, inspection area determination, defect detection, defect type discrimination, and good product judgment, but the present invention is not limited to this . For example, it is also possible to perform edge detection, effective area detection, inspection area determination, defect detection, defect type discrimination, and good product judgment by parts other than the control unit.

In addition, in the above-mentioned embodiment, it is shown that the defect of the device chip is detected by comparing whether the difference between the corresponding image (brightness) of the inspection area of the device chip and the image (brightness) of the good device chip is greater than a specific threshold. However, the present invention is not limited to this. For example, methods other than the method of comparing whether the difference in brightness is greater than a specific threshold can also be used to detect defects in the device chip.

In addition, in the above-mentioned embodiment, the defect and the crack are detected as an example of the defect, but the present invention is not limited to this. For example, it can also detect defects other than defects and cracks (film peeling, etc.).

In addition, in the above-mentioned embodiment, the example in which the element wafer is judged to be defective regardless of whether the crack reaches the effective area or not is shown, but the present invention is not limited to this. For example, as long as the extension line of the crack does not involve the effective area, the device chip can be judged as a good product.

In addition, in the above embodiment, it is shown that the no-entry area and the effective area are almost the same However, the present invention is not limited to this. For example, the no-entry area may be different from the effective area.

In addition, in the above-mentioned embodiment, an example in which both the effective area and the peripheral area are used as the inspection area is shown, but the present invention is not limited to this. For example, as shown in FIG. 12, the effective area 171 may not be used as the inspection area, and only the peripheral area 172 may be used as the inspection area 175 (the part shown by the diagonal line in FIG. 12). In this case, the image of the good component wafer becomes the image of the component wafer before cutting before cutting including only the peripheral area.

70‧‧‧Component chip

70a‧‧‧Component chip

70b‧‧‧Component chip

70c‧‧‧Component chip

70d‧‧‧Component chip

71‧‧‧effective area

72‧‧‧peripheral area

72a‧‧‧The part on the Y1 direction side of the effective area

72b‧‧‧The part arranged on the Y2 direction side of the effective area

72c‧‧‧The part on the Y1 direction side of the effective area

72d‧‧‧The part on the Y2 direction side of the effective area

74‧‧‧Edge

75‧‧‧Inspection area

75a‧‧‧Inspection area

90‧‧‧Defect

90a‧‧‧Defect

90b‧‧‧Crack

W1‧‧‧Width

W2‧‧‧Width

W3‧‧‧Width

W4‧‧‧Width

W5‧‧‧Width

Claims (5)

A defect inspection device, comprising: an imaging unit that photographs an element wafer including an effective area formed with an element and a peripheral area provided on the periphery of the effective area; an edge detection unit based on the imaging obtained by the imaging unit The image of the element wafer detects the edge outside the peripheral area of the element wafer; an effective area detection section detects the effective area of the element wafer based on the image of the element wafer captured by the imaging section The inspection area determination section, which determines the inspection area for inspecting the defect of the element chip based on the detected edge outside the peripheral area and the effective area; and the defect detection section, which determines the inspection area for inspecting the defect of the element chip by The corresponding image of the inspection area is compared with the image of the device chip of the good product stored in advance to detect the defect of the device chip; the image of the device chip of the good product includes a plurality of the effective areas, and The element wafer before cutting, which is disposed between the plurality of effective areas and includes the cutting area of the peripheral area, includes at least the peripheral area of the effective area and the peripheral area, and is inspected with and The corresponding method of the size of the peripheral region of the target element chip determines the image of the part corresponding to the size of the peripheral region in the image of the good-quality element chip. For example, the defect inspection device of claim 1, which further includes: a defect type judging unit that judges the type of the defect based on the shape of the detected defect; and a good product judging unit based on the judgment of the defect type judging unit Of the above defects The type and the position of the defect relative to the effective area determine whether the device chip is a good product or a defective product. For example, the defect inspection device of claim 2 is configured as follows: when the defect type determination unit determines that the defect is the defect of the element chip based on the shape of the defect, the good product determination unit reaches the above-mentioned defect In the case of the effective area, the element chip is judged to be a defective product, and in the case of the defect that does not reach the effective area, the element chip is judged to be a good product. For example, the defect inspection device of claim 2, which is configured as follows: when the defect type judgment unit judges that the defect is the crack of the element chip based on the shape of the defect, the good product judgment unit does not care about the crack Whether it reaches the above-mentioned effective area or not, the above-mentioned element wafer is judged as defective. For example, the defect inspection device of claim 3 is configured as follows: when the defect type determination unit determines that the defect is a crack of the element chip based on the shape of the defect, the good product determination unit does not care about the crack Whether it reaches the above-mentioned effective area or not, the above-mentioned element wafer is judged as a defective product.

Images