Defect inspection apparatus and defect inspection method

Abstract

The present invention provides a defect inspection apparatus and defect inspection method that can detect defects in rectangular element chips with greater accuracy. [Solution] This defect inspection device comprises an imaging unit that images a rectangular element chip 83, and a control unit that detects defects in the surrounding region 83b of the element chip 83 by acquiring an outer peripheral line L1 and determination lines L2 and L3 based on the image 60 of the element chip 83 captured by the imaging unit. The control unit sets a determination line L3 inside the corner region C by connecting the intersections of the boundary line of the corner region C and each of the pair of determination lines L2 along each adjacent side of the element chip 83, so that they are closer to the element formation region 83a than if each of the pair of determination lines L2 were extended.

Description

[Technical Field]

[0001] This invention relates to a defect inspection apparatus and a defect inspection method, and more particularly to a defect inspection apparatus and a defect inspection method for detecting defects in element chips. [Background technology]

[0002] Conventionally, defect inspection devices that detect defects in element chips using image processing are known (see, for example, Patent Documents 1 and 2).

[0003] Patent Document 1 describes a defect inspection device for detecting defects in element chips formed by cutting a substrate. This defect inspection device detects defects in an inspection area that includes the effective area on the element chip where the element is formed and the peripheral area provided at the periphery of the effective area, based on an image of the element chip that has been captured. The defect inspection device described in Patent Document 1 detects defects in an element chip by comparing an image corresponding to the inspection area of ​​the element chip with an image of a good element chip that has been stored in advance.

[0004] Furthermore, Patent Document 2 describes a processing apparatus for dividing a workpiece, including a semiconductor wafer, into individual chips. This processing apparatus performs a kerf check, which is performed by examining an image of the planned division line after cutting to confirm whether there are any abnormalities such as chips in the processing marks. In the processing apparatus described in Patent Document 2, after cutting is performed to divide the chips, the kerf check is performed by determining whether the cutting grooves fit within the width of the set planned division line, based on an image of the cutting grooves. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6752593 [Patent Document 2] Japanese Patent Publication No. 2021-30323 [Overview of the Initiative]

Problems to be Solved by the Invention

[0006] Here, when detecting defects of an element chip based on a captured image of the element chip as in Patent Documents 1 and 2 above, it is conceivable to capture the element chip after being divided into rectangles and detect defects such as chips occurring from the end portions of the outer periphery of the element chip toward the inside based on a preset determination line. In that case, it is considered that over-detection may occur in which defects are detected more than necessary at the corners at the four corners of the rectangular element chip. Specifically, when setting a linear determination line along each side of the rectangular element chip and detecting a defect that has reached the determination line from the end portion of the outer periphery of the element chip, the position of the intersection of the determination lines at the four corners of the element chip is, compared to the position on the determination line in the middle portion of each side, at a position away from the effective region (element formation region) where elements are formed in the element chip by the length of the diagonal line. Therefore, at the four corners of the element chip, a detection target region is formed where a defect is detected up to a position more separated from the element formation region than the distance required for defect detection, resulting in over-detection of defects. Therefore, it is desired to more accurately detect defects when detecting defects of a rectangular element chip by appropriately setting the determination lines at the four corners of the element chip.

[0007] This invention has been made to solve the above problems, and one object of this invention is to provide a defect inspection apparatus and a defect inspection method capable of more accurately detecting defects when detecting defects of a rectangular element chip.

Means for Solving the Problems

[0008] To achieve the above objective, a defect inspection apparatus according to the first aspect of this invention includes an imaging unit that images a rectangular element chip including an element formation region on which an element is formed and a surrounding region provided around the element formation region, and a control unit that detects defects in the surrounding region of an element chip by acquiring outer peripheral lines arranged along the outer periphery of the surrounding region along each side of the rectangular element chip and determination lines arranged outside the element formation region and inside the outer peripheral lines, respectively, based on the image of the element chip captured by the imaging unit, wherein the control unit sets determination lines inside the corner region by connecting the intersection points of the boundary line of the corner region and each of the pair of determination lines along each adjacent side of the element chip, bringing them closer to the element formation region than if each of the pair of determination lines were extended.

[0009] In this first-phase defect inspection device, as described above, the control unit sets the judgment lines within the corner region based on the corner region set at the corner of the rectangular element chip. This is done by connecting the intersection points of the boundary line of the corner region and each of the pair of judgment lines along each adjacent side of the element chip, bringing them closer to the element formation area than if each of the pair of judgment lines were extended. As a result, in the corner regions set at the four corners of the rectangular element chip, the judgment lines are set closer to the element formation area than if each of the pair of judgment lines were extended. Therefore, the judgment lines within the corner region can be appropriately set by bringing them closer to the element formation area to suppress over-detection of defects. Consequently, the judgment lines at the four corners of the element chip can be appropriately set, allowing for more accurate detection of defects in the rectangular element chip.

[0010] In the defect inspection apparatus according to the first aspect described above, preferably, the control unit sets a curved or straight judgment line within the corner region. With this configuration, the shape of the judgment line within the corner region can be set more appropriately to match the shape of the corner of the element formation region where the element is formed. As a result, the judgment lines at the four corners of the element chip can be set more appropriately, and defects can be detected with greater accuracy when detecting defects in rectangular element chips.

[0011] In this case, preferably, the system further includes an operating unit that receives input from an operator, and the control unit sets a circular or elliptical arc-shaped determination line within the corner region and adjusts the curvature of the arc-shaped determination line based on the input received by the operating unit. With this configuration, the curvature of the arc-shaped determination line can be easily adjusted by the operator's input. As a result, the shape of the determination line within the corner region can be set more appropriately, and defects in rectangular element chips can be detected with greater accuracy.

[0012] In a defect inspection device that sets curved or straight judgment lines as described above, preferably, the device further includes an operation unit that receives input operations from an operator, and the control unit sets a rectangular corner area based on the input operations received by the operation unit. With this configuration, the rectangular corner area can be set by input operations from an operator, making it easier to set the appropriate position and size of the corner area. Therefore, since the appropriate corner area can be set more easily based on input operations from an operator, the judgment lines at the four corners of the element chip can be set more easily. As a result, when detecting defects in a rectangular element chip, defects can be detected more easily and accurately.

[0013] In the defect inspection apparatus according to the first aspect described above, preferably, a display unit is further provided to display the detection results of defects in the peripheral region of the element chip by the control unit, and the control unit displays the detection results on the display unit so that defects detected in the corner region and defects detected outside the corner region can be distinguished. With this configuration, defects detected in the corner region and outside the corner region can be easily distinguished by visually recognizing the detection results displayed on the display unit. Therefore, by visually recognizing the detection results, it is easy to recognize which region of the rectangular element chip a defect has been detected in.

[0014] A defect inspection method according to a second aspect of this invention comprises the steps of: acquiring an image of a rectangular element chip including an element formation region on which an element is formed and a surrounding region provided around the element formation region; acquiring an outer perimeter line arranged on the outer perimeter of the surrounding region along each side of the rectangular element chip based on the image; acquiring a determination line arranged along the outer perimeter line, outside the element formation region and inside the outer perimeter line, based on the image; and detecting a defect in the surrounding region of the element chip based on the outer perimeter line and the determination line, wherein the step of acquiring the determination line includes setting a determination line inside the corner region by connecting the intersection points of the boundary line of the corner region and each of a pair of determination lines along each adjacent side of the element chip, based on a corner region set at the corner of the rectangular element chip, so that the intersections are closer to the element formation region than when each of the pair of determination lines is extended.

[0015] In this second phase of defect inspection, as described above, the step of acquiring the judgment line includes setting the judgment line within the corner region by connecting the intersection points of the boundary line of the corner region and each of the pair of judgment lines along each adjacent side of the element chip, based on the corner region set at the corner of the rectangular element chip, and bringing them closer to the element formation area than if each of the pair of judgment lines were extended. As a result, in the corner regions set at the four corners of the rectangular element chip, the judgment line is set closer to the element formation area than if each of the pair of judgment lines were extended. Therefore, the judgment line within the corner region can be appropriately set by bringing it closer to the element formation area to suppress over-detection of defects. Thus, since the judgment line at the four corners of the element chip can be appropriately set, a defect inspection method that can detect defects in rectangular element chips with greater accuracy can be provided. [Effects of the Invention]

[0016] As described above, the defect inspection apparatus and defect inspection method of the present invention can detect defects in rectangular element chips with greater accuracy. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram showing the overall configuration of a defect inspection device according to one embodiment of the present invention. [Figure 2] This is a schematic plan view showing the configuration of the unit under inspection. [Figure 3] This is a plan view showing the component chip. [Figure 4] This is a diagram illustrating the operation of the imaging unit. [Figure 5] This figure shows an example of an image captured from a device chip. [Figure 6] This is a diagram illustrating the outer perimeter line and the judgment line. [Figure 7]This is a flowchart illustrating a defect inspection method according to one embodiment of the present invention. [Figure 8] This diagram illustrates the setting of the judgment line in the corner region. [Figure 9] This diagram illustrates how to adjust the curvature of the judgment line in the corner region. [Figure 10] This diagram shows an example of how the settings screen looks. [Figure 11] This figure shows an example of how detection results are displayed. [Figure 12] This figure shows a determination line according to a modified version of one embodiment of the present invention. [Modes for carrying out the invention]

[0018] The following describes embodiments of the present invention based on the drawings.

[0019] (Configuration of the defect inspection device) Referring to Figures 1 to 6, the configuration of a defect inspection apparatus 100 according to one embodiment of the present invention will be described.

[0020] As shown in Figure 1, the defect inspection device 100 is a device for inspecting defects 90 (see Figure 5) in element chips 83 (see Figure 2) contained in the unit under inspection 80 after dicing. The defect inspection device 100 comprises a moving stage 10, a base unit 20, a mounting table 30, an imaging unit 40, a control unit 50, a storage unit 51, a display unit 52, and an operation unit 53. The moving stage 10 includes an X-axis slider 11 and a Y-axis slider 12. The X-axis slider 11 is positioned on the base unit 20 and is configured to move the Y-axis slider 12, positioned above it, in the left-right direction (X direction) in Figure 1. The Y-axis slider 12 is positioned on the X-axis slider 11 and is configured to move the mounting table 30, positioned above it, in the depth direction (Y direction) in Figure 1. In the following description, one side of the X direction will be referred to as the X1 direction and the other side as the X2 direction. Furthermore, in Figure 1, the far side in the Y direction will be referred to as the Y1 direction, and the near side as the Y2 direction. Also, in Figure 1, the height direction will be referred to as the Z direction, and in the Z direction, the direction in which the height increases will be referred to as the Z1 direction, and the direction in which the height decreases will be referred to as the Z2 direction.

[0021] The mounting table 30 is positioned on the Y-axis slider 12. The mounting table 30 is configured to be moved in the X and Y directions by the moving stage 10. The mounting table 30 is configured to have the unit to be inspected 80 placed on its upper surface (Z1 side).

[0022] The imaging unit 40 is configured to image a rectangular element chip 83 (see Figures 2 and 3) which includes an element formation region 83a on which elements (patterns) are formed and a peripheral region 83b around the element formation region 83a on which no elements are formed. The imaging unit 40 includes a lens barrel 41, a half mirror 42, an objective lens 43, and an imaging camera 44. The imaging camera 44 includes a light-receiving element 44a. The light-receiving element 44a includes, for example, an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). The imaging camera 44 is configured to output the imaged image 60 (see Figure 5) of the imaged element chip 83 to a control unit 50, which will be described later.

[0023] Furthermore, as shown in Figure 4, the imaging unit 40 is configured to sequentially image a plurality of element chips 83 that move relative to the imaging unit 40. Specifically, the element chips 83 are moved relative to the imaging unit 40 by the moving stage 10.

[0024] As shown in Figure 1, the control unit 50 controls the operation of each part of the defect inspection device 100. The control unit 50 is also configured to inspect defects 90 (see Figure 5) based on the captured image 60 (see Figure 5), which is an image of the element chip 83 captured by the imaging unit 40. In this embodiment, the control unit 50 is configured to detect defects 90 in the surrounding area 83b of the element chip 83 based on the captured image 60 captured by the imaging unit 40. The storage unit 51 is configured to store data sent from the control unit 50. The storage unit 51 is a storage medium that stores programs and parameters for operating the control unit 50. The control unit 50 performs control using the programs and parameters stored in the storage unit 51. The control unit 50 is, for example, one or more computers having an arithmetic unit such as a CPU (Central Processing Unit). The control unit 50 may be composed of hardware such as a personal computer, processor, or circuitry. The storage unit 51 includes a storage device such as flash memory or an HDD (Hard Disk Drive). The detailed operation of the control unit 50 and the detailed operation of the storage unit 51 will be described later.

[0025] The display unit 52 displays images and text information generated by the control unit 50. For example, the display unit 52 displays the captured image 60 (see Figure 5) and the setting screen 61 (see Figure 10) generated by the control unit 50. The display unit 52 also displays the detection result 62 (see Figure 11) of defects 90 in the element chip 83 by the control unit 50. The display unit 52 includes, for example, a display monitor. The operation unit 53 receives input operations from the operator. The operation unit 53 also outputs a signal to the control unit 50 indicating the received input operation. The operation unit 53 includes, for example, a keyboard and a pointing device such as a mouse.

[0026] (Configuration of the unit under inspection) As shown in Figure 2, the unit under inspection 80 includes a frame 81, a sheet member 82, and an element chip 83. The frame 81 and the element chip 83 are arranged on the surface (Z1 side) of the sheet member 82. The element chip 83 is a semiconductor wafer divided by a dicing area DA, which is shown by a dashed line. The dicing area DA is a region cut by a blade or laser during the dicing process. The sheet member 82 is a flexible sheet that is stretched in a post-dicing process to expand the spacing between multiple element chips 83. The lower surfaces (Z2 side) of the multiple element chips 83 and the upper surface (Z1 side) of the sheet member 82 are fixed together, for example, by adhesive. The frame 81 is made of a material with relatively high hardness, such as SUS, to improve the portability of the unit under inspection 80. The frame 81 also has a ring shape.

[0027] As shown in Figure 3, the element chip 83 includes an element formation region 83a and a surrounding region 83b. The surrounding region 83b is provided around the element formation region 83a and is larger than the element formation region 83a. Multiple element chips 83 are arranged in a matrix on the surface of the sheet member 82, with the dicing area DA in between. The element chip 83 has a rectangular shape, and the element formation region 83a also has a rectangular shape. The element chip 83 is a semiconductor chip in which a semiconductor element is formed in the element formation region 83a.

[0028] (Image captured) As shown in Figure 5, the captured image 60 displays the sheet member 82 (dicing area DA) and the element chip 83. In addition, during the dicing process, defects 90 may occur that extend from the outer edge (end) of the element chip 83 (outer region 83b) toward the element formation region 83a, which is inward, due to the surrounding region 83b being cut by a blade or the like.

[0029] As shown in Figure 6, in this embodiment, the control unit 50 acquires, based on the captured image 60 captured by the imaging unit 40, an outer peripheral line L1 arranged along each side of the rectangular element chip 83 on the outer periphery of the surrounding region 83b, and determination lines L2 and L3 arranged along the outer peripheral line L1, outside the element formation region 83a and inside the outer peripheral line L1. The control unit 50 is configured to detect defects 90 in the surrounding region 83b of the element chip 83 by acquiring the outer peripheral line L1 and the determination lines L2 and L3 based on the captured image 60. Specifically, the control unit 50 sets a rectangular outer peripheral line L1 that follows the outer shape of the element chip 83, a determination line L2 formed by a straight line portion, and a determination line L3 in a corner region C connecting the two straight determination lines L2. Based on the outer peripheral line L1 and the determination lines L2 and L3, the control unit 50 detects defects 90 that are in contact with the outer peripheral line L1 and at least one of the determination lines L2 and L3.

[0030] For example, Figure 6 shows examples where defect candidates 90a, 90b, and 90c occur as candidates for defect 90 extending from the left side (X1 side) of the element chip 83. In the following explanation, the left side (X1 side) of the element chip 83 and the element formation region 83a will be referred to as the left side, the lower side (Y2 side) as the bottom side, the right side (X2 side) as the right side, and the upper side (Y1 side) as the top side. Defect candidate 90a is an example of a defect extending from the upper end (corner) of the left side of the element chip 83. Defect candidate 90b is an example of a relatively large defect extending from the left side of the element chip 83 toward the left side of the element formation region 83a. Defect candidate 90c is an example of a relatively small defect extending from the left side of the element chip 83 toward the left side of the element formation region 83a. The control unit 50 is configured to detect multiple defect candidates 90a, 90b, and 90c based on the captured image 60, and to detect a defect 90 from among the detected multiple defect candidates 90a, 90b, and 90c using the outer edge line L1 and the determination lines L2 and L3. In the example shown in Figure 6, the control unit 50 detects defect candidate 90b as defect 90.

[0031] (Control processing for defect inspection methods) Here, with reference to Figures 7 to 11, a defect inspection method for an element chip 83 according to one embodiment of the present invention will be described. Note that the control processing from step S1 to step S8 is performed by the control unit 50. The defect inspection method in this embodiment is performed on a unit under inspection 80 which includes an element chip 83 divided into rectangles by a dicing process.

[0032] As shown in Figure 7, the defect inspection method according to this embodiment includes a step S1 to acquire an image 60, a step S2 to acquire an outer perimeter line L1, a step S3 to acquire a judgment line L2 in a straight section, a step S4 to set a corner region C, a step S5 to set a judgment line L3 in the corner region C, a step S6 to detect defect candidates 90a to 90c, a step S7 to detect a defect 90, and a step S8 to display the detection result 62.

[0033] First, in step S1 (see Figure 7), an image 60 in which the element chip 83 is captured is acquired. The image 60 may be an image of each element chip 83 individually, or it may be an image of each element chip 83 magnified and captured corner by corner. For example, the control unit 50 moves the unit under inspection 80, on which multiple element chips 83 are arranged, using the moving stage 10, and controls the operation of the imaging unit 40 to acquire multiple image 60 in which each of the multiple element chips 83 is captured individually. The control unit 50 acquires the acquired image 60 from the imaging unit 40 and stores it in the storage unit 51.

[0034] Next, in step S2 (see Figure 7), the outer perimeter line L1 is acquired in the captured image 60. The control unit 50 performs edge extraction image processing on the captured image 60, for example as shown in Figure 8, and acquires the outer perimeter line L1 by approximating the extracted edges in the outer perimeter of the element chip 83 with straight lines. The outer perimeter line L1 is acquired as a straight line indicating the boundary between the outer perimeter of the element chip 83 (surrounding region 83b) and the dicing area DA. That is, the outer perimeter line L1 is set as a straight line along each side at the edge of the outer perimeter of the rectangular element chip 83. Therefore, in the captured image 60, four outer perimeter lines L1 are set in a rectangular shape, each along one of the four sides of the rectangular element chip 83. For example, the control unit 50 performs edge extraction by detecting parts in the captured image 60 where the pixel values ​​change significantly. When setting the outer perimeter line L1 on the left side, the control unit 50 scans the brightness value of each pixel in the captured image 60 in the left-right direction (X direction) and detects the vicinity of pixels where the brightness value changes abruptly on the left side of the element chip 83 as the left edge of the element chip 83. The control unit 50 then sets the approximate straight line of the detected left edge of the element chip 83 as the outer perimeter line L1. The setting of the outer perimeter line L1 on the right side of the element chip 83 is done in the same way. Furthermore, when setting the outer perimeter line L1 on the bottom or top side of the element chip 83, the brightness value of each pixel in the captured image 60 is scanned in the up-down direction (Y direction).

[0035] Next, in step S3 (see Figure 7), a determination line L2 in the straight portion is acquired. For example, as shown in Figure 8, the control unit 50 detects the peripheral edge 84a of the element formation region 83a based on the captured image 60, and sets a straight determination line L2 along the peripheral edge 84a of the element formation region 83a. For example, the control unit 50 detects straight lines corresponding to each side of the peripheral edge 84a of the rectangular element formation region 83a by performing edge extraction image processing on the captured image 60. Then, the control unit 50 sets the determination line L2 at a position offset by α from each side of the detected peripheral edge 84a of the element formation region 83a toward the end of the element chip 83, using a preset offset value α. When setting the determination line L2 on the left side, the control unit 50 scans the brightness value of each pixel in the captured image 60 in the left-right direction (X direction) and detects the vicinity of pixels where the brightness value changes abruptly on the left side of the element formation region 83a as the left edge (periphery 84a) of the element formation region 83a. Then, it approximates the detected edge with a straight line and sets the determination line L2 offset by an offset value α to the outside or inside of the element formation region 83a. The offset value α is a value set in advance by the user and stored in the storage unit 51, which is read out by the control unit 50. The same procedure is followed for setting the determination line L2 on the right side of the element formation region 83a. Furthermore, when setting the determination line L2 on the bottom or top side of the element formation region 83a, the brightness value of each pixel in the captured image 60 is scanned in the up-down direction (Y direction).

[0036] Next, in step S4 (see Figure 7), a corner region C (see Figure 8) is set. As shown in Figure 8, in this embodiment, the control unit 50 sets a corner region C at each of the four corners of the rectangular element chip 83. Specifically, the control unit 50 sets a corner region C that includes the intersection of a pair of determination lines L2 corresponding to the outer peripheral line L1 along each adjacent side of the element chip 83. Since a rectangular element formation region 83a is formed in the rectangular element chip 83, the linear determination lines L2 along each side of the element formation region 83a are arranged to follow the outer peripheral line L1. The control unit 50 sets the corner region C to include the position of the intersection of the straight lines obtained by extending the determination lines L2 along the outer peripheral line L1 corresponding to the outer perimeter of the rectangular element chip 83. The corner region C is set, for example, in the surrounding region 83b outside the element formation region 83a.

[0037] In this embodiment, the control unit 50 sets a rectangular corner region C based on an input operation received by the operation unit 53. For example, the control unit 50 displays the captured image 60, or an image of the corners of the captured image 60 enlarged, on the display unit 52 so that it can be seen by the operator. The control unit 50 sets the corner region C based on an input operation by the operator who has seen the captured image 60 and specified the region. For example, the control unit 50 receives an input operation such as a drag operation using a pointing device such as a mouse as the operation unit 53, which allows the operation to specify the diagonal of the rectangular corner region C.

[0038] Next, in step S5 (see Figure 7), the determination line L3 in the corner region C is acquired. As shown in Figure 8, in this embodiment, the control unit 50 determines the intersection point P between the boundary line of the corner region C, shown by the dashed line, and each of the pair of determination lines L2 along each adjacent side of the element chip 83, based on the set corner region C. a and P bBy connecting the elements closer to the element formation region 83a side than when each of the pair of determination lines L2 is extended, a determination line L3 inside the corner region C is set. In the present embodiment, the control unit 50 sets a curved determination line L3 inside the corner region C. In the present embodiment, the control unit 50 sets a determination line L3 in the shape of an arc of a perfect circle or an ellipse inside the corner region C. That is, the control unit 50 sets the determination line L3 so as to be arranged closer to the element formation region 83a side than when the straight-line portions of the determination lines L2 are simply extended and crossed inside the corner region C. In the example of FIG. 8, the defect candidate 90a that was detected as a defect 90 when the straight determination line L2 was extended does not touch the determination line L3 and thus will not be detected as a defect 90.

[0039] For example, based on the set corner region C, the control unit ********** a and intersection point P b passes through, and a perfect circle centered on the point P o arranged at the corner of the corner region C, or an ellipse with the point P o arranged at the corner of the corner region C as a focus is obtained, and the portion of the obtained perfect circle or ellipse included in the corner region C is set as the curved determination line L3. For example, when the coordinates of the intersection point P a are (x a , y a ), and the coordinates of the intersection point P b are (x b , y b ), the coordinates of the corner point P o are represented as (x b , y a ). This point P o (x b , y a ) as the center, and the intersection point P a (x a , y a ) and the intersection point P b (x b , y b ) pass through the circle, or the point P o (x b , y aThe focus is on ) and the intersection P a (x a ,y a ) and intersection P b (x b ,y b The control unit 50 sets the determination line L3 by calculating an ellipse that passes through the specified line.

[0040] In this embodiment, the control unit 50 sets the determination lines L2 and L3 so that the determination lines L2 along the straight portions of each side of the rectangular element chip 83 and the determination lines L3 in the corner regions C are continuously connected to each other. The control unit 50 sets the determination lines L2 and L3 so that they surround the element formation region 83a around its entire circumference by connecting the determination lines L2 and L3 to each other. As described above, the control unit 50 sets the linear determination lines L2 along each of the four sides of the element formation region 83a, and then sets the corner regions C so that the determination lines L2 connect to each other, thereby setting the determination lines L3 at each of the four corners of the element chip 83.

[0041] <Adjusting the judgment line> Here, as shown in Figure 9, in this embodiment, the control unit 50 is configured to adjust the curvature of the arc-shaped determination line L3 based on the input operation received by the operation unit 53. The control unit 50 changes the curvature of the arc-shaped determination line L3 based on the input operation. For example, the control unit 50 sets a point P for setting the determination line L3 based on the input operation to the operation unit 53. o The control unit 50 changes the position of point P from its current position at the vertex of the corner of corner region C to its current position inward of corner region C. o Obtain the amount of movement required to move point P. For example, point P before adjustment. o The coordinates are (x b ,y a ) and the amount of movement obtained by the input operation is δ, then the adjusted point P o The coordinates are (x b -δ,y a-δ) is obtained. The control unit 50 determines point P based on the acquired amount of movement. o Move point P after the move. o Intersection point P with center a and intersection P b A perfect circle passing through, or the point P after the movement. o The intersection point P is the focus. a and intersection P b By obtaining an ellipse passing through it, the point P after the movement can be obtained. o The adjusted judgment line L3 is obtained. The adjusted judgment line L3 is the point P after movement. o Intersection point P with center a and intersection P b A perfect circle passing through, or the point P after the movement. o The intersection point P is the focus. a and intersection P b This corresponds to the portion of the corner region C of any ellipse passing through the point. In other words, the control unit 50 adjusts the curvature of the determination line L3 while maintaining a connection with the determination line L2. In the example in Figure 9, the determination line L3 before adjustment is shown as a dotted line, and the determination line L3 after adjustment is shown as a dashed line.

[0042] As shown in Figure 10, the control unit 50 displays a setting screen 61 for adjusting the curvature of the judgment line L3 on the display unit 52. Based on the input operation by the operator who has viewed the setting screen 61 displayed on the display unit 52, the control unit 50 adjusts point P in the curvature adjustment. o The amount of movement is set. For example, the control unit 50 accepts an operation to set the amount of movement by receiving input using the keyboard as the operation unit 53. The control unit 50 may also accept the setting of parameters for image processing of edge extraction in setting the outer perimeter line L1 or the judgment line L2 of the straight portion by displaying the setting screen 61 on the display unit 52.

[0043] The control unit 50 may, for example, accept input operations for setting the corner region C in step S4 and for adjusting the determination line L3 in step S5 for each of the four corners of the element chip 83. Alternatively, the control unit 50 may accept input operations for setting the corner region C in step S4 and for adjusting the determination line L3 in step S5 for one of the four corners of the element chip 83, and then apply the corner region C and determination line L3 set at one corner to the remaining corners to set the corner region C and determination line L3 at each of the four corners of one element chip 83. The control unit 50 may, for example, determine that the setting of determination lines L2 and L3 has been completed based on input operations that complete the setting of the corner region C and determination line L3. The steps for acquiring determination lines L2 and L3 are performed by executing the setting of determination line L2 in step S2, the setting of corner region C in step S3, and the setting of determination line L3 in step S4.

[0044] Next, in step S6 (see Figure 7), defect candidates 90a to 90c are detected. The control unit 50 detects defect candidates 90a to 90c by, for example, performing edge extraction image processing on the captured image 60. Specifically, the control unit 50 scans the brightness value of each pixel of the captured image 60 in at least one of the left-right direction (X direction) or up-down direction (Y direction), and detects the area surrounded by pixels where the brightness value changes abruptly as a defect candidate. For example, as shown in Figure 6, multiple defect candidates 90a, 90b, and 90c are detected from the captured image 60. Note that the control processing for defect candidate detection in step S6 may be performed before steps S2 to S5, or it may be performed in the middle of steps S2 to S5. For example, edge extraction image processing may be performed on the captured image 60, and based on the results of edge extraction, the setting of the outer perimeter line L1 in step S2, the setting of the judgment line L2 in step S3, and the detection of defect candidates 90a to 90c in step S6 may be performed.

[0045] Next, in step S7 (see Figure 7), a defect 90 is detected. As shown in Figure 6, the control unit 50 determines that, among the defect candidates 90a, 90b, and 90c detected in step S6, the defect candidate that reaches at least one of the determination lines L2 and L3 with the outer peripheral line L1 as the starting point is a defect 90. For example, the control unit 50 detects defect candidate 90b as a defect 90. Defect candidates 90a and 90c are in contact with the outer peripheral line L1 but are not in contact with either of the determination lines L2 and L3, and are therefore not detected as defects 90. The control unit 50 detects defects 90 on each side of the element chip 83 based on the captured image 60. In this embodiment, the control unit 50 also acquires position information indicating the location of the detected defect 90. For example, the control unit 50 acquires the coordinates of the detected defect 90 in the captured image 60 as position information. The control unit 50 stores the acquired position information in the storage unit 51.

[0046] Steps S2 to S7 are repeated for each element chip 83 included in the unit under inspection 80. Alternatively, the settings for the corner region C in step S4 and the judgment line L3 in step S5 may be performed on one of the multiple element chips 83, thereby allowing the other element chips 83 to use common settings. That is, the settings for the corner region C in step S4 and the judgment line L3 in step S5 may be performed on one element chip 83 by accepting input operations for setting the corner region C and adjusting the judgment line L3, while the settings for steps S4 and S5 may be made common to the other element chips 83 without accepting any input operations.

[0047] Next, in step S8 (see Figure 7), the detection result 62 (see Figure 11) is displayed on the display unit 52. As shown in Figure 11, the control unit 50 displays the detection result 62 of defects 90 in the surrounding region 83b of the element chip 83 on the display unit 52. The control unit 50 displays the defect 90 detected in step S7 and the location information of the defect 90 on the display unit 52. That is, in this embodiment, the control unit 50 displays the detection result 62 on the display unit 52 in such a way that it is possible to distinguish between defects 90 detected in the corner region C and defects 90 detected outside the corner region C. For example, the control unit 50 displays the "defect ID" indicating the number of the defect 90, the "chip address X" and "chip address Y" indicating which of the multiple element chips 83 it is, and the "X coordinate" and "Y coordinate" indicating the location of the detected defect 90 side by side on the display unit 52. The detection result 62 may also include information indicating the type, size, length, or width of the defect 90.

[0048] As described above, the control unit 50 acquires the captured image 60 and automatically sets the outer perimeter line L1 and the judgment line L2 based on the set parameters. It also accepts input operations to set the corner region C and to adjust the judgment line L3, thereby setting the judgment line L3. The control unit 50 then detects defects 90 from the captured image 60 based on the set outer perimeter line L1, judgment line L2, and judgment line L3. The control unit 50 may be configured with multiple computers, so that the main computer and the computer for image processing are provided separately, and the control processing of the overall operation of the defect inspection device 100 and image processing such as edge extraction are executed by different computers. Alternatively, the control unit 50 may be configured with a single computer so that the control processing from steps S1 to S8 is executed by a single computer.

[0049] (Effects of this embodiment) Next, the effects of this embodiment will be described.

[0050] In this embodiment, as described above, the control unit 50 determines the intersection point P between the boundary line of the corner region C and each of the pair of determination lines L2 that run along each adjacent side of the element chip 83, based on the corner region C set at the corner of the rectangular element chip 83. a and P b The judgment line L3 is set within the corner region C by connecting the two judgment lines L2 so that they are closer to the element formation region 83a than when each of the pair of judgment lines L2 is extended. As a result, in the corner region C set at the four corners of the rectangular element chip 83, the judgment line L3 is set closer to the element formation region 83a than when each of the pair of judgment lines L2 is extended. Therefore, the judgment line L3 within the corner region C can be appropriately set by being closer to the element formation region 83a to suppress over-detection of defects 90. Thus, the judgment line L3 at the four corners of the element chip 83 can be appropriately set, and when detecting defects 90 in the rectangular element chip 83, defects 90 can be detected with greater accuracy.

[0051] Furthermore, in this embodiment, based on the corner region C, the intersection point P of the boundary line of the corner region C and each of the pair of determination lines L2 is determined. a and P b By connecting them, a judgment line L3 is established within the corner region C, thus preventing interruptions in judgment lines L2 and L3 between the area outside the corner region C and the area inside the corner region C. Therefore, it is possible to effectively prevent the failure to detect defects 90 in both the corners and the areas outside the corners of the rectangular element chip 83.

[0052] Furthermore, in this embodiment, as described above, the control unit 50 sets a curved determination line L3 inside the corner region C. This allows the shape of the determination line L3 inside the corner region C to be set more appropriately to match the shape of the corner of the element formation region 83a where the element is formed. As a result, the determination line L3 at the four corners of the element chip 83 can be set more appropriately, so when detecting defects 90 in a rectangular element chip 83, the defects 90 can be detected with greater accuracy.

[0053] Furthermore, in this embodiment, as described above, the defect inspection device 100 includes an operation unit 53 that receives input operations from an operator. The control unit 50 sets a circular or elliptical arc-shaped determination line L3 within the corner region C. The control unit 50 then adjusts the curvature of the arc-shaped determination line L3 based on the input operations received by the operation unit 53. This allows the operator to easily adjust the curvature of the arc-shaped determination line L3 through input operations. As a result, the shape of the determination line L3 within the corner region C can be set more appropriately, and when detecting defects 90 in the rectangular element chip 83, the defects 90 can be detected with greater accuracy.

[0054] Furthermore, in this embodiment, as described above, the defect inspection device 100 includes an operation unit 53 that receives input operations from an operator. The control unit 50 sets a rectangular corner area C based on the input operations received by the operation unit 53. As a result, the rectangular corner area C can be set by an input operation from an operator, making it easier to set the appropriate position and size of the corner area C. Therefore, as the appropriate corner area C can be set more easily based on an input operation from an operator, the judgment line L3 at the four corners of the element chip 83 can be set more easily. As a result, when detecting defects 90 in the rectangular element chip 83, the defects 90 can be detected more easily and accurately.

[0055] Furthermore, in this embodiment, as described above, the defect inspection device 100 includes a display unit 52 that displays the detection results 62 of defects 90 in the surrounding region 83b of the element chip 83 by the control unit 50. The control unit 50 displays the detection results 62 on the display unit 52 so that it is possible to distinguish between defects 90 detected in the corner region C and defects 90 detected outside the corner region C. As a result, by visually recognizing the detection results 62 displayed on the display unit 52, it is possible to easily distinguish between defects 90 detected in the corner region C and outside the corner region C. Therefore, by visually recognizing the detection results 62, it is possible to easily recognize which region of the rectangular element chip 83 has a defect 90.

[0056] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0057] For example, in the above embodiment, the control unit 50 is shown to set a curved determination line L3 which is a perfect circle or an elliptical arc within the corner region C, but the present invention is not limited to this. In the present invention, the determination line within the corner region may be set by a curve other than a perfect circle or an ellipse. For example, the determination line within the corner region may be a hyperbola, a parabola, or a spline curve.

[0058] Furthermore, as shown in the modified example of the determination line L203 in Figure 12, the control unit 50 may set a straight determination line L203 within the corner region C. For example, a straight determination line L203, such as a bent straight line, may be set within the corner region C. Also, the intersection point P between the boundary line of the corner region C and each of the pair of determination lines L2. a and P bThe determination line in the corner region C may be set so that it connects the two points with a single straight line. By configuring the control unit 50 to set a straight determination line L203 inside the corner region C in this way, the shape of the determination line L203 inside the corner region C can be set more appropriately to match the shape of the corner of the element formation region 83a where the element is formed. As a result, the determination line L203 at the four corners of the element chip 83 can be set more appropriately, so that when detecting defects 90 in a rectangular element chip 83, the defects 90 can be detected with greater accuracy. Furthermore, compared to extending the determination line in the straight portion along the rectangular element chip 83 and directly connecting them to each other, it is preferable that the determination line in the corner region be shorter in length and positioned closer to the element formation region.

[0059] Furthermore, while the above embodiment shows an example in which the curvature of the circular or elliptical arc-shaped determination line L3 is adjusted by changing the curvature based on the input operation, the present invention is not limited to this. In the present invention, the curvature of the determination line curve in the corner region may be changed not by changing the curvature, but by deforming it to be closer to a straight line. Also, even when the determination line in the corner region is straight, the shape of the determination line may be adjusted based on the input operation. In addition, the shape of the determination line inside the corner region may be adjusted by changing the size, position, or shape of the corner region.

[0060] Furthermore, although the above embodiment shows an example in which a rectangular corner region C is set based on input operations, the present invention is not limited thereto. In the present invention, the shape of the corner region may be other than rectangular. In that case, a corner region of a shape other than rectangular may be set based on input operations by the operator. Alternatively, the corner region may be set automatically by detecting the corners of the element chip or the corners of the element formation area by image processing, rather than by input operations.

[0061] Furthermore, although the above embodiment shows an example in which the detection result 62 is displayed on the display unit 52, the present invention is not limited to this. In the present invention, it is not necessary to display the detection result on the display unit. For example, in cases where the defect inspection device is not equipped with a display unit, the acquired detection result may be output externally by communication or other means.

[0062] Furthermore, although the above embodiment shows an example in which a semiconductor is used as an element of the element chip 83, the present invention is not limited to this. In the present invention, materials other than semiconductors, such as simple wiring, may be used as elements of the element chip.

[0063] Furthermore, in the above embodiment, an example was shown in which the outer perimeter line L1 is detected by scanning the brightness value of each pixel in the captured image 60 in at least one of the left-right direction (X direction) or up-down direction (Y direction) using edge extraction image processing, and detecting the vicinity of pixels where the brightness value changes abruptly. However, the present invention is not limited to this. In the present invention, the outer perimeter line may be detected by binarizing the captured image. Alternatively, the outer perimeter line may be set based on input operations by the operator.

[0064] Furthermore, in the above embodiment, an example was shown in which the brightness value of each pixel in the captured image 60 is scanned in at least one of the left-right direction (X direction) or up-down direction (Y direction) by edge extraction image processing to detect the vicinity of pixels where the brightness value changes abruptly, thereby detecting the peripheral edge 84a of the element formation region 83a, and setting a determination line L2 offset to the outside or inside of the element formation region 83a by an offset value α. However, the present invention is not limited to this. In the present invention, a linear determination line in a linear portion may be set at a position offset toward the element formation region by a predetermined offset value from the outer peripheral line. That is, a determination line in a linear portion may be set without detecting the peripheral edge of the element formation region.

[0065] Furthermore, in the above embodiment, an example was shown in which the brightness value of each pixel in the captured image 60 is scanned in at least one of the left-right direction (X direction) or up-down direction (Y direction) by edge extraction image processing, and the area surrounded by pixels where the brightness value changes abruptly is detected as defect candidates 90a to 90c. However, the present invention is not limited to this. In the present invention, defect candidates may be detected by binarizing the image based on whether or not the brightness value of each pixel in the captured image exceeds a predetermined threshold.

[0066] Furthermore, in the above embodiment, the outer peripheral line L1 is shown as an example of an approximate straight line of the outer edge of the element chip 83, but the present invention is not limited to this. In the present invention, the outer peripheral line may be an approximate straight line of the outer edge of the element chip offset inward by a predetermined amount. [Explanation of Symbols]

[0067] 40 Imaging Unit 50 Control Unit 52 Display section 53 Operation section 60 captured images 62 Detection Results 83-element chip 83a Element formation region 83b Surrounding area 90 defects 100 Defect Inspection Equipment C Corner Area DA Dicing Area L1 Outer Line L2, L3 judgment lines

Claims

1. An imaging unit that images a rectangular element chip including an element formation region on which the element is formed and a surrounding region provided around the element formation region, The system includes a control unit that detects defects in the peripheral region of the element chip by acquiring, based on the image of the element chip captured by the imaging unit, an outer peripheral line arranged along each side of the rectangular element chip on the outer periphery of the peripheral region, and a determination line arranged outside the element formation region and inside the outer peripheral line, along the outer peripheral line. The control unit sets the determination lines within the corner region based on the corner region set at the corner of the rectangular element chip, by connecting the intersections of the boundary line of the corner region and each of the pair of determination lines along each adjacent side of the element chip, so that they are closer to the element formation region than if each of the pair of determination lines were extended.

2. The defect inspection apparatus according to claim 1, wherein the control unit sets the curved or straight determination line within the corner region.

3. It further includes an operating section that accepts input operations from the operator, The control unit, Within the aforementioned corner region, the determination line is set in the shape of a perfect circle or an ellipse arc. The defect inspection apparatus according to claim 2, wherein the curvature of the curve of the arc-shaped determination line is adjusted based on the input operation received by the operation unit.

4. It further includes an operating section that accepts input operations from the operator, The defect inspection apparatus according to claim 2, wherein the control unit sets the rectangular corner area based on the input operation received by the operation unit.

5. The system further includes a display unit that displays the results of defect detection in the surrounding region of the element chip by the control unit, The defect inspection apparatus according to any one of claims 1 to 4, wherein the control unit displays the detection results on the display unit so as to be able to distinguish between defects detected in the corner region and defects detected outside the corner region.

6. The steps include acquiring an image of a rectangular element chip that includes an element formation region where an element is formed and a surrounding region provided around the element formation region, Based on the captured image, the steps include obtaining an outer perimeter line arranged along each side of the rectangular element chip on the outer perimeter of the surrounding region, A step of obtaining a determination line that is located outside the element formation region and inside the outer peripheral line, and is positioned along the outer peripheral line, based on the captured image; The system includes the step of detecting a defect in the surrounding region of the element chip based on the outer peripheral line and the determination line, A defect inspection method comprising the step of obtaining the determination line, which includes setting the determination line within the corner region by connecting the intersection points of the boundary line of the corner region and each of the pair of determination lines along each adjacent side of the element chip, based on the corner region set at the corner of the rectangular element chip, so that the intersection points are closer to the element formation region than if each of the pair of determination lines were extended.

Images