JP2016156830A - Substrate inspection device and adjusting method of substrate inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate inspection device capable of inspecting a minute cavity which can occur in a joining interface even if there is a portion not transmitting inspection light in either of two joined substrate layers.SOLUTION: A substrate inspection device 100 includes: a light source unit 30 for radiating inspection light in a belt like manner so as to be obliquely incident to a surface of the substrate 100; and a line sensor camera 20 arranged at a prescribed position opposite to the light source unit 30 across a belt like irradiated region formed on the surface of the substrate by the inspection light. Substrate image information is generated on the basis of a video signal output from the line sensor camera 20 while the light source unit 30 and the line sensor camera 20 are moved relatively to the substrate 100. Inspection result information for a minute cavity occurring in a joining interface between a first substrate layer 101 and a second substrate layer 102 of the substrate 100 is generated on the basis of the substrate image information.SELECTED DRAWING: Figure 1A

Description

  In the embodiment of the present invention, the inspection of the presence / absence of a microcavity (void) at the bonding interface or the position, size, shape, etc. of the microcavity in a substrate such as a semiconductor wafer formed by bonding two wafers. The present invention relates to a substrate inspection apparatus, a substrate inspection method, and an optical system adjustment method in the substrate inspection apparatus.

  Conventionally, a defect inspection apparatus for detecting an unbonded defect (void) at a bonding interface in a semiconductor wafer (bonded wafer) formed by bonding two wafers (substrate layers) has been proposed (see Patent Document 1). ). In this defect inspection apparatus, infrared light (inspection light) is irradiated so as to be perpendicularly incident on one surface of a semiconductor wafer (bonded wafer), and the other surface of the semiconductor wafer is imaged by an infrared TV camera. If there is no defect at the wafer bonding interface in the semiconductor wafer, the infrared light incident from one surface passes through the semiconductor wafer and exits from the other surface as it is. If there is a microcavity), the infrared light is reflected at the unbonded defect portion, and the intensity of the transmitted infrared light at that portion is reduced. Therefore, in a photographed image obtained by an infrared TV camera, a portion corresponding to an unbonded portion appears darker than a portion corresponding to a normally bonded portion, and can be distinguished from each other. Therefore, a dark portion in a predetermined region of the semiconductor wafer is extracted from the photographed image, and a dark portion that should be an unbonded defect is detected based on the size of the dark portion.

JP-A-63-139237

  However, in the conventional inspection apparatus described above, since it is necessary to irradiate and transmit infrared light to a semiconductor wafer, infrared light such as a metal wiring or a light shielding film does not pass through any of the two wafers to be bonded. The inspection of the semiconductor wafer in which the portion exists cannot be performed.

  The embodiment of the present invention has been made in view of such circumstances, and even if there is a portion through which inspection light does not transmit in either of the two bonded substrate layers, the inspection light is used to attach the substrate to the substrate. Provided are a substrate inspection apparatus and a substrate inspection method capable of inspecting a microcavity that may be generated at a mating interface.

  The embodiment of the present invention also provides an optical system adjustment method in such a substrate inspection apparatus.

  In the substrate inspection apparatus according to the embodiment of the present invention, a microcavity that may be generated at the interface between the first substrate layer and the second substrate layer of the substrate in which the first substrate layer and the second substrate layer are bonded to each other. A substrate inspection apparatus for inspecting an illumination unit that irradiates inspection light of a predetermined wavelength so as to be incident obliquely on the surface of the substrate, and a band-shaped illumination region formed on the substrate by the inspection light A line sensor camera disposed at a predetermined position on the opposite side of the illumination unit; a moving mechanism that causes the substrate, the line sensor camera, and the illumination unit to move relative to each other in a direction across the belt-shaped illumination area; An image processing unit for processing a video signal from the line sensor camera, and the image processing unit moves relative to the illumination unit and the line sensor camera and the substrate. Substrate image information generating means for generating substrate image information representing an image of the substrate based on a video signal output from the line sensor when the moving mechanism is used; and the substrate based on the substrate image information. The test result information generating means generates test result information about a microcavity that may be generated at the interface between the first substrate layer and the second substrate layer.

  In addition, the substrate inspection method according to the embodiment of the present invention is a micro-pattern that may occur at the interface between the first substrate layer and the second substrate layer of the substrate in which the first substrate layer and the second substrate layer are bonded together. A substrate inspection method for inspecting a cavity, wherein the illumination unit is irradiated with inspection light having a predetermined wavelength so as to be incident obliquely on the surface of the substrate, and is formed on the substrate by the inspection light. A substrate scanning step in which the line sensor camera disposed at a predetermined position on the opposite side of the illumination unit across the strip-shaped illumination area and the illumination unit are relatively moved in a direction across the strip-shaped illumination area; and the substrate Image information representing an image of the substrate based on a video signal output from the line sensor when the illumination unit and the line sensor camera are moved relative to each other A substrate image information generation step for generating, and inspection result information generation for generating inspection result information about a microcavity that may occur at an interface between the first substrate layer and the second substrate layer in the substrate based on the substrate image information. And a step.

  With such a configuration, in a state where the inspection light from the illumination unit is irradiated in a strip shape so as to be obliquely incident on the surface of the substrate, the illumination unit sandwiches the strip-shaped illumination region formed on the substrate by the inspection light. Is output from the line sensor camera when the line camera sensor / illumination unit and the substrate move relative to each other while maintaining the positional relationship between the line sensor camera arranged at a predetermined position opposite to the light source unit and the light source unit Board image information is generated based on the video signal. By using the inspection light that passes through the substrate, the line sensor camera can receive the reflected light at the interface between the first substrate layer and the second substrate layer. In this case, the board image information generated based on the video signal from the line sensor camera may represent an image related to the interface between the first board layer and the second board layer. Based on the substrate image information, inspection result information about a microcavity that may be generated at the interface between the first substrate layer and the second substrate layer is generated.

  Furthermore, in the substrate inspection apparatus according to the embodiment of the present invention, the minute substrate that can be generated at the interface between the first substrate layer and the second substrate layer of the substrate in which the first substrate layer and the second substrate layer are bonded together. A substrate inspection apparatus for inspecting a cavity, wherein an illumination unit irradiates a predetermined wavelength of inspection light in a strip shape so as to be incident obliquely on the surface of the substrate, and a strip illumination formed on the substrate by the inspection light A line sensor camera and an area sensor camera arranged side by side in a predetermined positional relationship on the opposite side of the illumination unit across an area, and the line sensor camera and the area sensor camera are moved together to perform the line sensor camera. And a camera adjustment mechanism for adjusting a relative position and posture of the area sensor camera with respect to the strip-shaped illumination area of the board, and the board and the line sensor camera. And a moving mechanism that moves the light source unit relative to each other in a direction across the strip-shaped illumination area, an image processing unit that processes video signals from the area sensor camera and the line sensor camera, and a display unit. The image processing unit includes an area image display control means for displaying an image on the display unit based on a video signal from the area sensor camera, and the band-like illumination area of the substrate by the illumination unit and the camera adjustment mechanism. When the relative movement between the line sensor camera adjusted to have a predetermined positional relationship and the substrate is performed by the moving mechanism, the substrate is detected based on the video signal output from the line sensor camera. Board image information generating means for generating board image information representing an image, and the board image information A configuration and a test result information generating means for generating a test result information about the microcavities which may occur at the interface between the second substrate layer and the first substrate layer in the substrate Zui.

  With such a configuration, in a state where the inspection light is irradiated in a strip shape so as to be incident obliquely on the surface of the substrate, while confirming the image displayed on the display unit based on the video signal from the area sensor camera, A line sensor camera that is in a predetermined positional relationship with the area sensor camera is moved by a camera adjustment mechanism so that the relative positional relationship of the substrate with the band-shaped illumination area is within a predetermined position relationship, for example, from the band-shaped illumination area. The inspection light reflected at the interface between the first substrate layer and the second substrate layer can be adjusted so that the line sensor camera can receive the inspection light. Then, substrate image information is generated based on a video signal output from the line sensor camera when the line sensor camera, the illumination unit, and the substrate in which the positional relationship is maintained move relative to each other. If the line sensor camera is adjusted so that the inspection light reflected at the interface between the first substrate layer and the second substrate layer of the substrate is incident as described above, the substrate image information is stored in the first substrate layer. And an image relating to an interface between the second substrate layer and the second substrate layer. Based on the substrate image information, inspection result information about a microcavity that may be generated at the interface between the first substrate layer and the second substrate layer is generated.

  An adjustment method for a substrate inspection apparatus according to an embodiment of the present invention is the adjustment method for the substrate inspection apparatus, wherein an image based on a video signal from the area sensor camera is displayed on a display unit, The area sensor camera and the line sensor camera are moved together by the camera adjustment mechanism so that the image of the strip-shaped illumination area formed on the substrate is at a predetermined position on the screen of the display unit, and the area sensor camera And an area sensor camera adjustment step for adjusting a relative position and posture of the substrate of the line sensor camera with respect to the strip-shaped illumination region, and a relative positional relationship of the line sensor camera with respect to the strip-shaped illumination region of the substrate, The band of the substrate of the area sensor camera adjusted by the area camera adjustment step To be the same as the relative positional relationship with respect to the illumination area, a structure having a line sensor camera adjustment step of moving integrally with the line sensor camera and the area sensor camera by the camera adjustment mechanism.

  With such a configuration, while confirming the image displayed on the display unit based on the video signal from the area sensor camera, the relative positional relationship between the line sensor camera and the strip-shaped illumination area formed on the substrate is set to a predetermined value. Positional relationship, for example, a positional relationship in which inspection light reflected at the interface between the first substrate layer and the second substrate layer by traveling further obliquely through the substrate from the strip-shaped illumination region can be received by the line sensor camera. Can be adjusted as follows.

  According to the substrate inspection apparatus and the substrate inspection method of the present invention, the inspection light is obliquely incident on the surface of the substrate without transmitting the inspection light through both the first substrate layer and the second substrate layer, and the inspection is performed. Substrate image information that can represent the state of the interface between the first substrate layer and the second substrate layer is generated based on a video signal from a line sensor camera that receives reflected light from the substrate, and based on the substrate image information As a result, the inspection result information is generated, so even if any of the bonded substrate layers (the first substrate layer and the second substrate layer) does not transmit the inspection light, the inspection light is used to attach the inspection result information to the substrate. It becomes possible to inspect microcavities that may be generated at the mating interface.

  Furthermore, according to the adjustment method of the substrate inspection apparatus according to the present invention, the relative positional relationship with the belt-like illumination area formed on the substrate of the line sensor camera is adjusted while confirming the captured image with the area sensor camera. Therefore, the position and orientation of the line sensor camera can be easily adjusted so that substrate image information that can represent the state of the interface between the first substrate layer and the second substrate layer can be generated.

It is a top view which shows the state which becomes the relationship where an area sensor camera and an illumination unit oppose in the basic composition of the inspection apparatus which concerns on embodiment of this invention. It is a top view which shows the state used as the relationship which a line sensor camera and an illumination unit oppose in the fundamental structure of the board | substrate inspection apparatus which concerns on embodiment of this invention. It is a side view which shows the basic composition of the board | substrate inspection apparatus which concerns on embodiment of this invention. It is a block diagram which shows the basic composition of the processing system in the board | substrate inspection apparatus which concerns on embodiment of this invention. It is a flowchart which shows the adjustment procedure (the 1) of the area sensor camera and line sensor camera in a board | substrate inspection apparatus. It is a flowchart which shows the adjustment procedure (the 2) of an area sensor camera and a line sensor camera in a board | substrate inspection apparatus. It is a figure which shows the specific structure of an illumination unit, and the strip | belt-shaped illumination area | region (the 1) formed in the interface in a board | substrate by the illumination unit. It is a figure which shows the specific structure of an illumination unit, and the strip | belt-shaped illumination area | region (the 2) formed in the interface in a board | substrate by the illumination unit. It is a figure which shows the 1st example (when appropriate) of the strip | belt-shaped illumination area | region formed in the interface in a board | substrate. It is a figure which shows the 2nd example (when improper) of the strip | belt-shaped illumination area | region formed in the interface in a board | substrate. It is a figure which shows the 3rd example (when improper) of the strip | belt-shaped illumination area | region formed in the interface in a board | substrate. It is a figure which shows the 4th example (when improper) of the strip | belt-shaped illumination area | region formed in the interface in a board | substrate. It is a figure which shows the example of adjustment of an optical system. It is a figure which shows the other example of adjustment of an optical system. It is a flowchart which shows the flow of the process which concerns on the test | inspection in a processing unit. It is a figure which shows the shape model of the void which may arise in the interface of a 1st board | substrate layer and a 2nd board | substrate layer. It is a figure which shows the example of the board | substrate image obtained with the line sensor camera. It is a figure which expands and shows the part A in the image shown in FIG. It is a figure which shows the image after the background removal of the image shown in FIG. It is a figure which expands and shows the part B in the image shown in FIG.

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

  A substrate inspection apparatus according to an embodiment of the present invention is configured as shown in FIGS. 1A, 1B and 2. The substrate inspection apparatus includes a first wafer layer 101 (bare wafer: first substrate layer) on a surface of the second wafer layer 102 (pattern wafer: second substrate layer) on which the circuit pattern is formed. A semiconductor wafer 100 (substrate) made of Si (silicon), which is bonded to each other, is an inspection target (see FIG. 2), and a microcavity (bonding) that may be generated at the interface between the first wafer layer 101 and the second wafer layer 102. Is a microscopic part that is not perfect but is a void, and is inspected for voids).

  In FIG. 1A, FIG. 1B, and FIG. 2, this board | substrate inspection apparatus has the area sensor camera 10, the line sensor camera 20, the illumination unit 30, the conveyance mechanism 40, the slide mechanism 50, the camera moving mechanism 51, and the rotation mechanism 52. Yes. The transport mechanism 40 (moving mechanism) carries the semiconductor wafer 100 to be inspected and linearly moves at a predetermined speed, and can move stepwise in a direction B orthogonal to the linear movement direction A. ing. The illumination unit 30 is disposed above the semiconductor wafer 100 that is moved by the transport mechanism 40, and can pass through the semiconductor wafer 100 made of Si having a predetermined wavelength so as to be obliquely incident on the surface of the semiconductor wafer 100. For example, the inspection light in the infrared band having a wavelength of 1070 nm or the like is irradiated in a band shape. The incident angle of the inspection light irradiated from the light source unit 30 on the surface of the semiconductor wafer 100 (the angle of the inspection light with respect to the normal of the surface) is set to a predetermined angle, for example, in the range of 20 ° to 30 °. Then, a strip-shaped illumination region Epj (see FIGS. 6 to 8D described later) extending in a direction crossing the moving direction A of the semiconductor wafer 100 is formed on the surface of the semiconductor wafer 100 by the inspection light irradiated from the illumination unit 30, for example. Then, the inspection light is guided into the semiconductor wafer 100 along the optical axis of the illumination unit 30.

  The area sensor camera 10 and the line sensor camera 20 are arranged side by side on the opposite side of the illumination unit 30 with a strip-shaped illumination area Epj formed on the semiconductor wafer 100 by inspection light emitted from the illumination unit 30 interposed therebetween. In addition, optical devices (lenses and the like) constituting each of the area sensor camera 10 and the line sensor camera 20 can easily adjust the optical conditions of the line sensor camera 20 based on the optical conditions adjusted by the area sensor camera 10. The same thing is used so that it can be done. The line sensor camera 20 is set so that an imaging line (an array of light receiving elements) extends in a direction crossing the moving direction A of the semiconductor wafer 100, specifically, in a direction B orthogonal to the moving direction A. If the positional relationship between the area sensor camera 10 and the line sensor camera 20 is fixedly determined in advance as a relationship in which the strip-shaped illumination area Epj formed on the semiconductor wafer 100 can be photographed, It is not limited. In the case of this example, the area sensor camera 10 and the line sensor camera 20 are tilted at an angle at which the reflected light from the semiconductor wafer 100 of the inspection light irradiated obliquely from the illumination unit 30 can be received, for example. The direction is the same, and further, along the direction B perpendicular to the moving direction A of the semiconductor wafer 100 in a positional relationship in which the imaging center of the area sensor camera 10 and the imaging line of the line sensor camera 20 are on the same line. Is arranged in.

  The slide mechanism 50, the camera moving mechanism 51, and the rotating mechanism 52 function as a camera adjustment mechanism that moves the area sensor camera 10 and the line sensor camera 20 together to adjust their positions and postures. The slide mechanism 50 slides the area sensor camera 10 and the line sensor camera 20 arranged in the relative positional relationship as described above in a direction B orthogonal to the moving direction A of the semiconductor wafer 100. As shown in FIG. 2, the camera moving mechanism 51 moves the area sensor camera 10 and the line sensor camera 20 together with the slide mechanism 50 independently of the shooting direction D and the direction S orthogonal thereto. The rotating mechanism 52 rotates the area sensor camera 10 and the line sensor camera 20 together with the camera moving mechanism 51 and the slide mechanism 50 around an axis extending in parallel with the direction B orthogonal to the moving direction A of the semiconductor wafer 100. The slide mechanism 50 slides in the direction B, the camera movement mechanism 51 moves in the shooting direction D and the direction S perpendicular thereto, and the rotation mechanism 52 rotates around an axis parallel to the direction B. The relative position and posture of the sensor camera 10 and the line sensor camera 20 with respect to the strip-shaped illumination area Epj formed on the semiconductor wafer 100 can be adjusted.

  In the substrate inspection apparatus having the above-described structure, when the semiconductor wafer 100 is moved in the direction A by the transfer mechanism 40, the line sensor camera 20 and the illumination unit 30 that are in a fixed positional relationship maintain their positional relationship. However, it moves relative to the semiconductor wafer 100 in parallel to the surface thereof and in a direction opposite to the moving direction (A direction) of the semiconductor wafer 100. Thereby, an optical scan of a quarter region of the semiconductor wafer 100 is performed by the line sensor camera 20. Then, the transport mechanism 40 moves stepwise in the direction B perpendicular to the direction A, so that the optical scanning area (one of the four areas) of the semiconductor wafer 100 by the line sensor camera 20 is switched. Optical scanning of the entire wafer 100 by the line sensor camera 20 becomes possible.

  In FIG. 3, the processing unit 60 functions as an image processing unit that processes video signals from the area sensor camera 10 and the line sensor camera 20. The processing unit 60 that receives the video signal from the area sensor camera 10 causes the display unit 61 to display a captured image of the area sensor camera 10 based on the video signal. The processing unit 60 also includes wafer image information representing an image of the semiconductor wafer 100 based on a video signal from the line sensor camera 20 that optically scans the semiconductor wafer 100 in synchronization with the movement of the semiconductor wafer 100 by the transport mechanism 40. (Substrate image information) is generated, and inspection result information about voids that may occur at the interface between the first wafer layer 101 and the second wafer layer 102 is generated based on the wafer image information. An operation unit 62 and a display unit 61 are connected to the processing unit 60, and the processing unit 60 acquires information related to various instructions according to the operation of the operation unit 62, and the captured image of the area sensor camera 10 described above. In addition, various information such as inspection result information is displayed on the display unit 61.

  The inspection light (infrared light) emitted from the illumination unit 30 can be reflected at the surface of the semiconductor wafer 100 and part of the inspection light can travel inside and be reflected at the interface between the first wafer layer 101 and the second wafer layer 102. . In this board inspection apparatus, since the infrared light that is the inspection light is not visible light, the operator cannot directly adjust the visual inspection light by visual inspection. Therefore, the adjustment is based on the photographed image displayed on the display unit 61. The position and orientation of the line sensor camera 20 so that the line sensor camera 20 can receive the inspection light reflected at the interface between the first wafer layer 101 and the second wafer layer 102 of the semiconductor wafer 100 more efficiently. Can be adjusted. The adjustment of the line sensor camera 20 includes a position adjustment (area sensor camera adjustment step) of the area sensor camera 10 having a fixed positional relationship with the line sensor camera 20, and a position adjustment (line sensor camera adjustment step) of the line sensor camera 20. ) And made. Specifically, the adjustment is performed according to the procedure shown in FIGS. The illumination unit 30 is set in advance so that the incident angle of the inspection light with respect to the surface of the semiconductor wafer 100 is a predetermined angle (for example, a range of 20 ° to 30 °) as described above, and the area sensor camera 10 and the line sensor camera 20 are also positioned so that the inspection light from the illumination unit 30 can be reflected by the semiconductor wafer 100 (interface between the first wafer layer 101 and the second wafer layer 102). 2 is adjusted in advance, and the relative positional relationship with the illumination unit 30 (S direction and D direction in FIG. 2) is adjusted to some extent in advance.

  The integrated position adjustment (area sensor camera adjustment step) of the area sensor camera 10 with the line sensor camera 20 is performed according to the procedure shown in FIGS.

  In FIG. 4, the gain and exposure time of the area sensor camera 10 are adjusted so that a captured image can be obtained properly (S11), and the focal length of the illumination unit 30 is adjusted so that the surface of the semiconductor wafer 100 is properly illuminated. (S12). A captured image is displayed on the display unit 61 based on the video signal from the area sensor camera 10 under the control of the processing unit 60 according to the operation of the operation unit 62. In this state, the operator operates the operation unit 62 to operate the transport mechanism 40 while viewing an image taken by the area sensor camera 10 displayed on the display unit 61, and the camera moving mechanism 51 and the slide mechanism 50. Next, adjustment of the position of the area sensor camera 10 (positions in the S direction and D direction in FIG. 2), adjustment of the focal length, illuminance, and illumination range of the illumination unit 30, and adjustment of the lens conditions of the area sensor camera 10 are performed. (S13 to S20).

  First, the semiconductor wafer 100 is moved to a position photographed by the area sensor camera 10 while viewing the photographed image by the area sensor camera 10 displayed on the display unit 61 (S13). In this state, the camera moving mechanism 51 and the rotating mechanism 52 are operated so that the image of the strip-shaped illumination area Epj formed on the surface of the semiconductor wafer 100 by the inspection light from the illumination unit 30 is a predetermined position on the screen of the display unit 61. For example, the position (S direction and D direction shown in FIG. 2) and the attitude (rotation angle θ) of the area sensor camera 10 (line sensor camera 20) are adjusted so as to be in the center (S14). As a result, the imaging center of the area sensor camera 100 is positioned at the center of the strip-shaped illumination area Epj, and the inspection light from the illumination unit 30 is regularly reflected on the surface of the semiconductor wafer 100, and the inspection light is the strongest. The area sensor camera 10 is adjusted to a position where light can be received (see FIG. 9). That is, the area sensor camera 100 is positioned on the optical axis where the inspection light from the illumination unit 30 is regularly reflected on the surface of the semiconductor wafer 100. Then, while looking at the image taken by the area sensor camera 10 displayed on the screen of the display unit 61, the lens conditions of the area sensor camera 10 (for example, the f value that represents the aperture value of the lens and the focal length of the lens). By adjusting the reciprocal value (D value or the like), an image of the interface between the first wafer layer 101 and the second wafer layer 102 (void or second wafer layer 102) is displayed on the captured image displayed on the screen of the display unit 61. The circuit pattern formed on the surface is adjusted so as to be reflected (S15). Thereafter, while observing the image taken by the area sensor camera 10 displayed on the screen of the display unit 61, the strip illumination area Epj is formed at the interface between the first wafer layer 101 and the second wafer layer 102 by the light irradiated from the illumination unit 30. And the illumination unit 30 is readjusted (focal length, illuminance, irradiation range) so that the image of the interface (the void and the circuit pattern formed on the surface of the second wafer layer 102) is reflected more clearly. Etc.) (S16).

  When the illumination unit 30 includes a plurality of infrared LEDs and a reflecting mirror (elliptical mirror), as shown in FIGS. 6 and 7, the infrared rays emitted from the plurality of infrared LEDs are reflected and collected by the reflecting mirror (elliptical mirror). For example, a strip-shaped illumination region Epj extending in a direction crossing the moving direction A is formed at the interface in the semiconductor wafer 100 by the light. If the position of the illumination unit 30 with respect to the interface in the semiconductor wafer 100 is not appropriate, the strip-shaped illumination area Epj spreads out in the moving direction A of the semiconductor wafer 100 as shown in FIG. When the infrared light emitted from the light source is not sufficiently condensed on the strip-shaped illumination area Epj by the reflector, and the position of the illumination unit 30 relative to the interface in the semiconductor wafer 100 is appropriate, the strip-shaped illumination area Epj is 7, a clear state in which the spread of the semiconductor wafer 100 in the moving direction A is suppressed (the infrared light emitted from the plurality of infrared LEDs is sufficiently applied to the strip-shaped illumination region Epj by the reflecting mirror). The light is condensed). More specifically, if the position and posture of the illumination unit 30 with respect to the interface in the semiconductor wafer 100 are appropriate, the strip-shaped illumination region Epj extends in the moving direction A of the semiconductor wafer 100 as shown in FIG. 8A. Is in a clear state, and the center line Lc has the maximum illuminance distribution. Although the parallelism with respect to the interface in the semiconductor wafer 100 of the illumination unit 30 is maintained, when the distance to the interface in the semiconductor wafer 100 is not appropriate, as shown in FIG. In the moving direction A, the image becomes blurred. When the parallelism with respect to the interface in the semiconductor wafer 100 of the illumination unit 30 is not maintained, as shown to FIG. 8C, the strip | belt-shaped illumination area Epj will be in the state which spread gradually toward the other from one side. When the parallelism with respect to the interface in the semiconductor wafer 100 of the illumination unit 30 is maintained, but the parallelism with the area sensor camera 10 is not maintained, the strip-shaped illumination area Epj expands as shown in FIG. 8D. Although it is in a suppressed and clear state, the semiconductor wafer 100 is inclined with respect to a direction B perpendicular to the moving direction A.

  By adjusting the illumination unit 30 (S16), along with the adjustment of the illuminance, the strip-shaped illumination region Epj is formed at the interface between the first wafer layer 101 and the second wafer layer 102 in the semiconductor wafer 100 displayed on the screen of the display unit 61. The position and posture of the lighting unit 30 are adjusted so as to be formed as shown in FIG. 8A.

  Next, while displaying an image captured by the area sensor camera 10 on the screen of the display unit 61, the camera moving mechanism 51 is operated to move the area sensor camera 10 together with the line sensor camera 20 in a direction away from the illumination unit 30. It is moved by the distance (offset movement) (S17). Details of the offset movement (S17) will be described later. An image of the interface between the first wafer layer 101 and the second wafer layer 102 (a void or a circuit pattern formed on the surface of the second wafer layer 102) is further added to the captured image displayed on the screen of the display unit 61. The lens conditions (for example, f value, D value, etc.) of the area sensor camera 10 are readjusted so as to be reflected (S18). Thereafter, the imaging position of the semiconductor wafer 100 is changed (S19), and the imaging position is changed in the same procedure (S15 to S16) as described above (for example, the scanning end position of the line sensor camera 20). The area sensor camera 10 and the illumination unit 30 are readjusted so that the image of the interface between the first wafer layer 101 and the second wafer layer 102 is reflected in the captured image displayed on the screen of the display unit 61 ( S20).

  By adjusting the area sensor camera 10 and the light source unit 30 as described above, the moving direction A of the semiconductor wafer 100 is formed on the interface between the first wafer layer 101 and the second wafer layer 102 of the semiconductor wafer 100 as shown in FIG. 8A. The band-shaped illumination region Epj extending in the direction B perpendicular to the moving direction A is obtained by suppressing the spread to the region and providing a clear state, the center line Lc being the maximum illuminance distribution of the reflected light at the interface. It is formed. The imaging center of the area sensor camera 10 is from the center line Lc of the strip-shaped illumination area Epj formed on the surface of the semiconductor wafer 100 (the strip-shaped portion where the illuminance distribution of the inspection light specularly reflected on the surface of the semiconductor wafer 100 is maximum). Then, the state is set (offset movement) at a position shifted by a predetermined distance in a direction away from the light source unit 30.

  Since the adjustment of the position and orientation of the area sensor camera 10 described above is performed integrally with the line sensor camera 20, the positional relationship between the line sensor camera 20 and the strip-shaped illumination area Epj formed on the semiconductor wafer 100 is an area. The positional relationship between the sensor camera 10 and the strip illumination area Epj is shifted by the relative positional relationship between the line sensor camera 20 and the area sensor camera 10. In this case, the area sensor camera 10 and the line sensor camera 20 have the same shooting direction, and the positional relationship in which the shooting center of the area sensor camera 10 and the shooting line of the line sensor camera 20 are on the same line. Since the semiconductor wafer 100 is arranged side by side along a direction B orthogonal to the moving direction A of the semiconductor wafer 100, the positional relationship between the line sensor camera 20 and the belt-like illumination area Epj of the semiconductor wafer 100 is the same as that of the area sensor camera 20 and the belt-like illumination. The positional relationship with the illumination area Epj is shifted in the extending direction B of the band-shaped illumination area Epj by the distance between the center of the imaging line of the line sensor camera 20 and the imaging center of the area sensor camera 10.

  When the adjustment of the area sensor camera 10 (line sensor camera 20) and the illumination unit 30 (the procedure shown in FIG. 4) is completed as described above, the adjustment of the line sensor camera 20 is performed according to the procedure shown in FIG. Camera adjustment step).

  In FIG. 5, the slide mechanism 50 is operated, and the line sensor camera 20 and the area sensor camera 10 are slid by the relative positional relationship between the line sensor camera 20 and the area sensor camera 10 (S21). Thereby, the center (imaging axis) of the imaging line of the line sensor camera 20 becomes the position of the imaging center (imaging axis) of the area sensor camera 10 whose position and orientation are adjusted as described above. In this state, the relationship between the line sensor camera 20 and the strip illumination area Epj formed at the interface within the semiconductor wafer 100 is the relationship between the area sensor camera 10 and the strip illumination area Epj when adjusted as described above. Be the same. That is, a position where the photographing line of the line sensor camera 20 is shifted by a predetermined distance in a direction away from the illumination unit 30 from the center line Lc (a strip portion having the maximum illuminance) of the strip illumination area Epj formed on the surface of the semiconductor wafer 100. Is set (offset movement).

  Thereafter, the lens conditions (for example, f value, D value, etc.) of the line sensor camera 20 are set to be the same as those of the area sensor camera 10 (S22), and the gain and exposure time of the line sensor camera 20 are adjusted. (S23). For the line sensor camera 20 whose gain and exposure time have been adjusted, the lens conditions are readjusted (S24). When the position adjustment of the line sensor camera 20 and the setting of the lens conditions are completed, the transfer speed of the semiconductor wafer 100 by the transfer mechanism 40 is set using the operation unit 62 (S25).

  With the adjustment for the line sensor camera 20 completed as described above, the transfer mechanism 40 transfers the semiconductor wafer 100 at the set transfer speed under the control of the processing unit 60, and thereby in the direction A. The moving semiconductor wafer 100 is optically scanned by the line sensor camera 20 in which the relative positional relationship with the illumination unit 30 is maintained (photographing by the line sensor camera 20). In the process, the video signal output from the line sensor camera 20 is supplied to the processing unit 60. Then, the processing unit 60 generates wafer image information representing an image of the interface between the first wafer layer 101 and the second wafer layer 102 of the semiconductor wafer 100 based on the video signal from the line sensor camera 20. As described above, since the semiconductor wafer 100 is scanned by being divided into four parts, the wafer image information obtained by the respective scans is combined and the first wafer layer 101 and the second wafer layer 102 of the semiconductor wafer 100 are combined. Wafer image information representing the entire interface is generated.

  The imaging line of the line sensor camera 20 (imaging center of the area sensor camera 10) illuminates from the portion of the center line Lc of the strip-shaped illumination area Epj formed on the surface of the semiconductor wafer 100 (the strip-shaped portion having the maximum illuminance distribution). The reason why the position is shifted (offset movement) by a predetermined distance in the direction away from the unit 30 is as follows.

  When the inspection light (infrared light) incident obliquely on the surface of the semiconductor wafer 100 (first wafer layer 101) from the illumination unit 30 is represented by its optical axis, as shown in FIG. 9, the semiconductor wafer 100 (first wafer) The component reflected on the surface of the layer 101) (see the solid line in FIG. 9) and the first wafer layer 101 are transmitted through the first wafer layer 101 and reflected at the interface Sb between the first wafer layer 101 and the second wafer layer 102. The component which radiate | emits from the surface (refer the broken line in FIG. 9) is included. Since the inspection light is obliquely incident on the semiconductor wafer 100 and the first wafer layer 101 has a thickness, the component reflected at the interface Sb between the first wafer layer 101 and the second wafer layer 102 is a semiconductor. The component that is reflected from the surface of the wafer 100 (first wafer layer 101) is shifted in a direction away from the illumination unit 30. Therefore, the position of the line sensor camera 20 that optically scans the semiconductor wafer 100 follows the procedure shown in FIGS. 4 and 5 described above, as shown in FIG. Is centered on the center line Lc of the strip-shaped illumination area Epj formed on the surface of the semiconductor wafer 100 (the strip-shaped portion where the illuminance distribution is maximized) by a predetermined distance Δ in a direction away from the illumination unit 30. Adjusted to Accordingly, the line sensor camera 20 that optically scans the semiconductor wafer 100 while maintaining the relative positional relationship with the illumination unit 30 always has an interface Sb between the first wafer layer 101 and the second wafer layer 102. More of the reflected component is included. That is, the line sensor camera 20 can more efficiently receive the most strongly reflected component of the inspection light reflected at the interface Sb between the first wafer layer 101 and the second wafer layer 102 of the semiconductor wafer 100. It becomes like this. For example, when the incident angle of the inspection light is 20 °, the refractive index of the first wafer layer 101 (Si layer) is 3.5, and the thickness thereof is 750 μm, the imaging line of the line sensor camera 20 is The position is offset (offset movement) by 140 to 150 μm in the direction away from the illumination unit 30 from the portion of the center line Lc of the strip-shaped illumination area Ebj formed on the surface of the semiconductor wafer 100 (the strip-shaped portion having the maximum illuminance distribution). )

  As described above, the line sensor camera 20 is adjusted to a position where the reflected light at the interface Sb between the first wafer layer 101 and the second wafer layer 102 in the semiconductor wafer 100 can be received more. The wafer image information generated by the processing unit 60 based on the video signal output from the sensor camera 20 may include more information indicating the state of the interface Sb between the first wafer layer 101 and the second wafer layer 102. Therefore, as will be described later, the processing unit 60 generates accurate inspection result information about voids that may occur at the interface Sb between the first wafer layer 101 and the second wafer layer 102 based on the wafer image information. Will be able to.

  Further, the position and orientation of the line sensor camera 20 are adjusted while confirming the captured image displayed on the display unit 61 based on the video signal from the area sensor camera 10, so that the line sensor camera 20 outputs the image. As in the case of adjusting the positions and orientations of the illumination unit 30 and the line sensor camera 20 only by the image based on the image signal, the semiconductor sensor 100 is scanned by the line sensor camera 20 each time the adjustment is performed, and the wafer image information is obtained. There is no need to generate the image, and the adjustment time for shooting by the line sensor camera 20 is shortened. Further, even if infrared light that cannot be directly observed by the operator is used as inspection light, the adjustment can be performed while viewing the captured image displayed on the display unit 61 based on the video signal from the area sensor camera 10. The relative positional relationship between the sensor camera 20 and the strip-shaped illumination area Epj formed on the semiconductor wafer 100 is further advanced obliquely from the strip-shaped illumination area Epj through the semiconductor wafer 100 (first wafer layer 101) to the first wafer layer. The inspection light reflected at the interface Sb between the first wafer layer 102 and the second wafer layer 102 can be easily adjusted so that the positional relationship can be received by the line sensor camera 20.

  In this inspection apparatus, the area sensor camera 10 also captures an image of the interface between the first wafer layer 101 and the second wafer layer 102 (a void or a circuit pattern formed on the surface of the second wafer layer 102). However, since the angle of view of the captured image of the area sensor camera 10 is wide, a component reflected on the surface of the semiconductor wafer 100 and a component reflected on the interface are selectively extracted. It is not suitable for receiving light. On the other hand, since the angle of view of the line sensor camera 20 is extremely narrow compared to the area sensor camera 10, the line sensor camera 20 is set at a position shifted as described above (offset movement), so that the component reflected on the surface is at the interface. The reflected component becomes dominant, and the reflected light from the interface can be received efficiently. Therefore, as described above, when adjusting the photographed image, adjustment is performed using the image from the area sensor camera 10 for convenience, and when generating wafer image information by interface photographing, the line sensor shifted by offset is used. An image signal is acquired by the camera 20.

  In the example described above, the imaging center of the area sensor camera 10 (imaging line of the line sensor camera 20) is the portion of the center line Lc of the strip-shaped illumination area Epj on the surface of the semiconductor wafer 100 (the strip-shaped portion where the illuminance distribution is maximized). Is set (offset movement) at a position shifted by a predetermined distance Δ in a direction away from the illumination unit 30 (see S17 in FIG. 4 and FIG. 9), but is not limited thereto. As shown in FIG. 10, the light source unit 30 may be shifted by a predetermined distance Δ in a direction away from the area sensor camera 10 (line sensor camera 20). Even in this case, the imaging line of the line sensor camera 20 is separated from the illumination unit 30 from the portion of the center line Lc of the strip-shaped illumination area Epj on the surface of the semiconductor wafer 100 (the strip-shaped portion where the illuminance distribution is maximized). The state is shifted by a predetermined distance Δ in the direction.

  The processing unit 60 for inputting the video signal output from the line sensor camera 20 that optically scans the semiconductor wafer 100 while maintaining the relative positional relationship with the illumination unit 30 adjusted as described above is shown in FIG. In accordance with the procedure shown in FIG. 5, a process related to inspection for voids that may occur at the interface Sb between the first wafer layer 101 and the second wafer layer 102 of the semiconductor wafer 100 is executed.

  In FIG. 11, the processing unit 60 generates wafer image information representing an image of the semiconductor wafer 100 based on a video signal from the line sensor camera 20 that scans the semiconductor wafer 100 by dividing the semiconductor wafer 100 into four (S31). As described above, the position of the line sensor camera 20 is adjusted so as to efficiently receive the reflected light at the interface Sb between the first wafer layer 101 and the second wafer layer 102. As shown in FIG. 13 and an enlarged partial image IM1 shown in FIG. 13, the image IM represented by is the first wafer layer 101 of the second wafer layer 102 as shown in FIG. 14. The image of the circuit pattern currently formed in the joint surface is included. The processing unit 60 performs processing for removing a background portion such as a circuit pattern on the wafer image information (S32). As a result, as shown in FIG. 15 by enlarging the partial image IM2 of the image IM1 in FIG. 14, the processed wafer image has the background portion such as the circuit pattern removed. The processing unit 60 detects a portion (void portion) corresponding to the void included in the wafer image based on the wafer image information representing the wafer image (see FIG. 15) from which the background portion such as the circuit pattern is removed (S33). ).

  Note that the dark annular interference fringes are inverted in brightness by image processing, and appear as bright (white) rings in FIGS. 15 and 16. Conversely, the bright annular interference fringes are inverted in brightness by image processing and appear as dark (black) rings in FIGS. 15 and 16.

  In the processing unit 60, as a void portion that can be included in the wafer image, for example, an annular image portion Bd1 in which interference fringes appear as shown in FIG. 16, a linear (circular) image portion Bd2, and other linear image portions are included. A non-annular image portion such as a point image portion is registered in advance. The processing unit 60 detects a void portion by extracting an image portion of the same type as an image portion (annular image portion, planar image portion, etc.) registered as a void portion from the obtained wafer image.

  When the void portion is detected from the wafer image, the processing unit 60 determines whether or not the extracted void portion includes the annular image portion Bd1 (S34). The interference fringes of the annular image portion Bd1 are generated by voids generated at the interface Sb between the first wafer layer 101 and the second wafer layer 102, and are reflected by the light reflected by the surface of the void on the first wafer layer 101 side and the second. It is considered that bright and dark stripes appear due to interference with the light reflected by the surface on the wafer layer 102 side (a stripe pattern similar to Newton rings). When there is the annular image portion Bd1 (YES in S34), the processing unit 60 uses the shape of the annular image portion Bd1 and the interference fringes (Newton's ring theory) to create a void corresponding to the void portion as follows. The curvature radius R is calculated.

As shown in FIG. 12, the void Bd formed at the interface Sb between the first wafer layer 101 and the second wafer layer 102 is modeled as a part of a sphere. In FIG.
v: radius of void r: radius of dark ring LNR (dark annular interference fringe) h: thickness of void s: distance from interface Sb to center O of radius of curvature. The radius v of the void and the radius r of the dark line ring LNR are measured from the annular image portion Bd1 (see FIG. 16) extracted as a void portion from the wafer image. In this embodiment, the radius v of the void is obtained by measuring the radius of the outermost dark line ring of the interference fringes of the extracted annular image portion Bd1.

  The void thickness h is

It is represented by From the condition of dark lines of interference fringes, if m is an integer,

It becomes. Here, d is the distance between AC in FIG. 12, and is the thickness of the void in the portion where the dark line ring LNR detected from the annular image portion Bd1 is generated.

From the triangle △ AOB,

From the triangle △ COD and Equation 3,

It becomes.

From d2 << r, R, d2 = 0, and from Equation 4,

It becomes.

From Equation 2, Equation 3, and Equation 6,

It becomes.

If the radius of the mth dark line is rm,

It becomes. Similarly, if the radius of the m + nth dark line is rm + n,

It becomes. Expand the right side of Equation 9 and substitute Equation 8

If the horizontal axis is n and the vertical axis is r2, the slope of the straight line is b.

It becomes. The slope b of the straight line is obtained by the method of least squares.

Is required.

  When the curvature radius R of the void is calculated as described above (S35), the processing unit 60 selects one target from the void portion extracted in step S33 (S36), and the selected one is selected. From the void portion, the size of the corresponding void (length, diameter, area, etc. in two directions) is measured and its thickness h is determined (S37). The void thickness h is calculated from the radius v of the void portion measured according to the above equation 1 and the curvature radius R (see equation 14) obtained as described above. In this example, since all the voids generated at the interface between the first wafer layer 101 and the second wafer layer 102 are uniform in the bonding conditions of the first wafer layer 101 and the second wafer layer 10, It is assumed that the same radius of curvature R is obtained. Then, the processing unit 60 determines whether or not the processing has been completed for all the extracted void portions (S38), and performs the same processing (S36 to S37) as described above for each void portion. Run. Thereby, the planar size and thickness h of the corresponding void are obtained from all the void portions extracted from the wafer image.

  For a void portion where the radius v cannot be obtained, such as appearing as a linear image portion, the thickness h is not obtained, and only the planar size is measured. Further, when the annular image portion is not extracted as the void portion from the wafer image (NO in S34), the void curvature radius R is not calculated for the semiconductor wafer 100. For this reason, the void thickness h is not calculated. In this case, only the planar size (length in two directions, radius, etc.) is obtained, but the radius of curvature R of the void may be obtained from a statistical value, and the thickness h of the void may be calculated. Further, when a plurality of annular image portions are extracted from the wafer image in the processing in step S34, the curvature radius R is calculated from each of the plurality of annular image portions by the procedure described above, and the obtained plurality of curvature radii R are obtained. It is also possible to calculate the void thickness h using the average value of.

  When the processing for all the void portions extracted from the wafer image is completed (YES in S38), the processing unit 60 performs measurement and measurement as described above together with the positions of the voids extracted from the wafer image on the wafer image. Based on the calculated planar size and thickness h of each void, inspection result information in a predetermined format (table format, graph format, etc.) is generated for the void (S39). For example, the number of voids, the position of each void, the planar size of each void, and the thickness h of each void are generated as inspection result information represented in a table format or the like. Then, the processing unit 60 causes the display unit 61 to display the inspection result information.

  According to the substrate inspection apparatus as described above, the inspection light is obliquely incident on the surface of the semiconductor wafer 100 without transmitting the inspection light through both the first wafer layer 101 and the second wafer layer 102, and the inspection is performed. Wafer image information that can represent the state of the interface Sb between the first wafer layer 101 and the second wafer layer 102 is generated based on the video signal from the line sensor camera 20 that receives the reflected light of the light on the semiconductor wafer 100, Since inspection result information is generated based on the wafer image information, even if there is a portion (circuit pattern or the like) through which the inspection light does not transmit in the second wafer layer 102 of the semiconductor wafer 100, the semiconductor wafer It becomes possible to inspect for voids that may occur at the bonding interface Sb at 100. Further, since information on the thickness h of each void is also obtained as inspection result information, the inspection result information does not reach the void and expose the circuit pattern on the surface of the second wafer layer 102, for example. In addition, it can be used as an index when the surface of the first wafer layer 101 is polished.

  In the above-described embodiment, the semiconductor wafer 100 is moved with respect to the line sensor camera 20 and the illumination unit 30 in which the relative positional relationship is maintained. However, the line sensor camera 20 and the optical unit 30 are moved to the semiconductor wafer. You may make it move with respect to 100. FIG.

  Moreover, although the above-described embodiment is a substrate inspection apparatus for the semiconductor wafer 100, the present invention is not limited to this, and can be applied to any substrate in which two substrate layers are bonded together. Thus, for example, a substrate or the like formed by bonding a sensor panel having a light-transmitting region such as a touch panel type liquid crystal display panel and a cover glass can be an inspection target.

  In this case, it is also possible to use visible light as the illumination unit.

  In the embodiment described above, the outermost dark line ring of the interference fringes is measured as the diameter of the void. However, on the outer side of the outermost dark line ring, the light reflected on the surface on the first wafer layer 101 side of the void generated at the interface Sb and the light reflected on the surface on the second wafer layer 102 side are formed. It is considered that there is a space that does not appear as bright and dark stripes due to interference, that is, does not appear as a dark line ring. That is, it can be considered that the actual microvoid as a void is larger than the diameter of the outermost dark line ring.

  Therefore, the substrate to be inspected by the above-described substrate inspection apparatus is also inspected by ultrasonic cavity inspection (SAT), and a correlation with the diameter of the void measured by the substrate inspection apparatus is obtained in advance. Then, the void diameter obtained by the substrate inspection apparatus is corrected as necessary using the correlation coefficient representing the obtained correlation (for example, the obtained void diameter is multiplied by the correlation coefficient). Therefore, a more accurate void diameter can be obtained. Then, by obtaining the void thickness based on the void diameter thus obtained, a more accurate void thickness can be obtained.

  It should be noted that the measurement of the diameter of the void in the ultrasonic cavity inspection has many restrictions such as that the object must be immersed in the liquid (see, for example, JP-A-9-229912) and the measurement takes time. Ultrasonic cavity inspection is not suitable for in-line measurements.

  In addition, the thickness of the void determined by the substrate inspection apparatus, the thickness of the void determined based on the correlation with the ultrasonic cavity inspection (SAT) described above, and the first wafer layer 101 performed using this as an index. By determining the correlation with the polishing information (polishing thickness) on the surface, the thickness of the void can be determined more accurately. That is, the surface of the first wafer layer 101 is polished based on the void thickness index actually obtained by the substrate inspection apparatus, and the result of the polishing (the void is exposed from the surface of the first wafer layer by the index). By feeding back whether or not, the theoretical value and the actual measurement value (the actual thickness of the void is not actually measured, but the actual thickness of the void can be assumed by the polishing thickness when the void is exposed) ) To increase the void thickness and index accuracy.

DESCRIPTION OF SYMBOLS 10 Area sensor camera 20 Line sensor camera 30 Illumination unit 40 Conveyance mechanism 50 Slide mechanism 51 Camera movement mechanism 52 Rotation mechanism 60 Processing unit 61 Display unit 62 Operation unit

Embodiments of the present invention relates to a method of adjusting the optical system in the substrate inspection equipment and board inspection apparatus.

The embodiment of the present invention has been made in view of such circumstances, and even if there is a portion through which inspection light does not transmit in either of the two bonded substrate layers, the inspection light is used to attach the substrate to the substrate. there is provided a substrate inspection equipment capable of inspecting a micro cavities that may occur in mating interface.

In the substrate inspection apparatus according to the embodiment of the present invention, a microcavity that may be generated at the interface between the first substrate layer and the second substrate layer of the substrate in which the first substrate layer and the second substrate layer are bonded to each other. A substrate inspection apparatus for inspecting, comprising: an illumination unit that irradiates a strip of inspection light having a predetermined wavelength so as to be obliquely incident on the surface of the substrate; and a strip-shaped illumination area formed on the substrate by the inspection light A line sensor camera and an area sensor camera arranged side by side in a predetermined positional relationship on the opposite side of the illumination unit, and the line sensor camera and the area sensor camera are integrally moved to A camera adjustment mechanism for adjusting a relative position and posture of the substrate of the area sensor camera with respect to the belt-like illumination area; the substrate; the line sensor camera; A moving mechanism for moving the light source unit in a direction crossing the belt-like illumination area, an image processing unit for processing video signals from each of the area sensor camera and the line sensor camera, and a display unit. The image processing unit includes area image display control means for displaying an image on the display unit based on a video signal from the area sensor camera, and the belt-like illumination area of the substrate by the illumination unit and the camera adjustment mechanism. When the relative movement between the line sensor camera adjusted to have a predetermined positional relationship and the substrate is performed by the moving mechanism, the image of the substrate is based on a video signal output from the line sensor camera. Board image information generating means for generating board image information representing A configuration and a test result information generating means for generating a test result information about the microcavities which may occur at the interface between the second substrate layer and the first substrate layer in the substrate.

An adjustment method for a substrate inspection apparatus according to an embodiment of the present invention is the adjustment method for the substrate inspection apparatus, wherein an image based on a video signal from the area sensor camera is displayed on a display unit, The area sensor camera and the line sensor camera are moved together by the camera adjustment mechanism so that the image of the strip-shaped illumination area formed on the substrate is at a predetermined position on the screen of the display unit, and the area sensor camera And an area sensor camera adjustment step for adjusting a relative position and posture of the substrate of the line sensor camera with respect to the strip-shaped illumination region, and a relative positional relationship of the line sensor camera with respect to the strip-shaped illumination region of the substrate, of the substrate of the area sensor camera adjusted by the area sensor camera adjustment step Serial to be the same as the relative positional relationship strip-like illumination area, a structure having a line sensor camera adjustment step of moving integrally with the line sensor camera and the area sensor camera by the camera adjustment mechanism.

According to the substrate inspection equipment according to the present invention, without transmitting both the first substrate layer and the second substrate layer inspection light, the inspection light is obliquely incident on the surface of the substrate, the substrate of the inspection light Substrate image information that can represent the state of the interface between the first substrate layer and the second substrate layer is generated based on the video signal from the line sensor camera that receives the reflected light at the substrate, and the inspection result based on the substrate image information Since information is generated, even if there is a portion where the inspection light does not pass through any of the bonded substrate layers (the first substrate layer and the second substrate layer), the inspection light is used for the bonding interface on the substrate. It becomes possible to inspect microcavities that may be generated.

Claims (19)

A substrate inspection apparatus for inspecting a microcavity that may be generated at an interface between the first substrate layer and the second substrate layer of a substrate formed by bonding a first substrate layer and a second substrate layer,
An illumination unit that irradiates inspection light of a predetermined wavelength so as to be incident obliquely on the surface of the substrate;
A line sensor camera arranged at a predetermined position on the opposite side of the illumination unit across a strip-shaped illumination area formed on the substrate by the inspection light;
A movement mechanism that causes the substrate, the line sensor camera, and the illumination unit to move relative to each other in a direction across the belt-shaped illumination area;
An image processing unit for processing a video signal from the line sensor camera,
The image processing unit includes:
When the moving mechanism is used to move the illumination unit, the line sensor camera, and the substrate relative to each other, the substrate image information representing the image of the substrate is generated based on a video signal output from the line sensor. Board image information generating means;
A substrate inspection apparatus comprising: inspection result information generating means for generating inspection result information about a microcavity that may be generated at an interface between the first substrate layer and the second substrate layer in the substrate based on the substrate image information.   In the line sensor camera, the photographing line of the line sensor camera is located at a position shifted by a predetermined distance in a direction away from the illumination unit from a strip portion where the illuminance distribution of the strip illumination area formed on the substrate is maximized. The board inspection apparatus according to claim 1, which is set in the board.   The line sensor camera is set so that a photographing line of the line sensor camera is shifted by a predetermined distance in a direction away from the illumination unit from a center line of a strip-shaped illumination area formed on the substrate. 1. The substrate inspection apparatus according to 1. The inspection result information generating means is a microcavity portion corresponding to a microcavity generated at the interface between the first substrate layer and the second substrate layer in the substrate image represented by the substrate image information based on the substrate image information. Means for detecting
The board | substrate inspection apparatus in any one of Claim 1 thru | or 3 which produces | generates the said inspection result information containing the information which concerns on the shape of the detected said microcavity part. The inspection result information generating means includes means for calculating information on the thickness of the microcavity as information on the shape of the microcavity,
The board | substrate inspection apparatus of Claim 4 which produces | generates the said test result information containing the information which concerns on the thickness of the said micro cavity part. The means for calculating information relating to the thickness of the microcavity part has means for extracting an annular image part from the detected microcavity part,
The substrate inspection apparatus according to claim 5, wherein information related to the thickness of the minute cavity portion is calculated based on the extracted interference fringe shape of the annular image portion. A substrate inspection method for inspecting a microcavity that may occur at an interface between the first substrate layer and the second substrate layer of a substrate formed by bonding a first substrate layer and a second substrate layer,
The illumination unit sandwiches the substrate and a strip-shaped illumination area formed on the substrate by the inspection light in a state in which the illumination unit is irradiated with inspection light having a predetermined wavelength so that the illumination unit is obliquely incident on the surface of the substrate. And a substrate scanning step for performing relative movement between the line sensor camera and the illumination unit arranged at a predetermined position on the opposite side to the belt-like illumination area,
Board image information generation for generating board image information representing an image of the board based on a video signal output from the line sensor when the board, the illumination unit, and the line sensor camera are relatively moved. Steps,
A substrate inspection method comprising: an inspection result information generation step of generating inspection result information about a microcavity that may occur at an interface between the first substrate layer and the second substrate layer in the substrate based on the substrate image information. The inspection result information generation step includes a microcavity corresponding to a microcavity generated at an interface between the first substrate layer and the second substrate layer in the substrate image represented by the substrate image information based on the substrate image information. Detecting
The substrate inspection method according to claim 7, wherein the inspection result information including information related to the shape of the detected microcavity is generated. The inspection result information generation step includes a step of calculating information on the thickness of the microcavity as information on the shape of the microcavity,
The substrate inspection method according to claim 8, wherein the inspection result information including information related to a thickness of the microcavity is generated. Calculating the information relating to the thickness of the microcavity portion includes extracting an annular image portion from the detected microcavity portion;
The board | substrate inspection method of Claim 9 which calculates the information which concerns on the thickness of the said micro cavity part based on the shape of the interference fringe of the extracted said annular image part. A substrate inspection apparatus for inspecting a microcavity that may be generated at an interface between the first substrate layer and the second substrate layer of a substrate formed by bonding a first substrate layer and a second substrate layer,
An illumination unit that irradiates a strip of inspection light having a predetermined wavelength so as to be incident obliquely on the surface of the substrate;
A line sensor camera and an area sensor camera arranged side by side in a predetermined positional relationship on the opposite side of the illumination unit across a strip-shaped illumination area formed on the substrate by the inspection light;
A camera adjustment mechanism for integrally moving the line sensor camera and the area sensor camera to adjust a relative position and posture of the line sensor camera and the area sensor camera with respect to the belt-like illumination area of the substrate;
A movement mechanism that causes the substrate, the line sensor camera, and the illumination unit to move relative to each other in a direction across the belt-shaped illumination area;
An image processing unit for processing a video signal from each of the area sensor camera and the line sensor camera;
A display unit,
The image processing unit includes:
Area image display control means for displaying an image on the display unit based on a video signal from the area sensor camera;
When the relative movement between the line sensor camera and the substrate adjusted to have a predetermined positional relationship with the belt-like illumination area of the substrate by the illumination unit and the camera adjustment mechanism is performed by the moving mechanism, Board image information generating means for generating board image information representing an image of the board based on a video signal output from the line sensor camera;
A substrate inspection apparatus comprising: inspection result information generating means for generating inspection result information about a microcavity that may be generated at an interface between the first substrate layer and the second substrate layer in the substrate based on the substrate image information.   The substrate inspection apparatus according to claim 11, wherein the area sensor camera and the line sensor camera are arranged side by side in a positional relationship in which shooting directions are the same.   The substrate inspection according to claim 12, wherein the area sensor camera and the line sensor camera are arranged side by side in a positional relationship in which a shooting center of the area sensor camera and a shooting line of the line sensor camera are on the same line. apparatus.   The substrate inspection apparatus according to claim 13, wherein the camera adjustment mechanism includes a slide mechanism that integrally slides the line sensor camera and the area sensor camera in a direction in which the belt-like illumination area of the substrate extends.   The relative position of the line sensor camera with respect to the belt-like illumination area of the substrate is determined by the camera adjustment mechanism so that the photographing line on the surface of the board of the line sensor camera is the illuminance distribution of the belt-like illumination area of the substrate. 5. The substrate inspection apparatus according to claim 1, wherein the substrate inspection apparatus is adjusted so as to be shifted by a predetermined distance in a direction away from the illumination unit from a belt-like portion where the maximum is.   The relative position of the line sensor camera with respect to the strip-shaped illumination area of the substrate is determined by the camera adjustment mechanism so that the imaging line on the surface of the substrate of the line sensor camera is the center line of the strip-shaped illumination area of the substrate. The substrate inspection apparatus according to claim 1, wherein the substrate inspection apparatus is adjusted so as to be shifted by a predetermined distance in a direction away from the illumination unit. A method for adjusting a substrate inspection apparatus according to any one of claims 11 to 16,
The area sensor camera is configured such that an image based on a video signal from the area sensor camera is displayed on a display unit, and an image of a strip-shaped illumination area formed on the substrate is at a predetermined position on the screen of the display unit. And an area sensor camera adjustment step of adjusting the relative position and posture of the area sensor camera and the line sensor camera with respect to the belt-like illumination area by integrally moving the line sensor camera by the camera adjustment mechanism; ,
The relative positional relationship of the line sensor camera with respect to the strip-shaped illumination region of the substrate is the same as the relative positional relationship of the substrate of the area sensor camera with respect to the strip-shaped illumination region adjusted by the area camera adjustment step. The substrate inspection apparatus adjustment method comprising: a line sensor camera adjustment step for integrally moving the line sensor camera and the area sensor camera by the camera adjustment mechanism. The substrate inspection apparatus to be adjusted is the substrate inspection apparatus according to claim 14,
In the line sensor camera adjustment step, the line sensor camera and the area sensor camera are integrally slid by the slide mechanism, and the relative positional relationship of the line sensor camera with respect to the belt-shaped illumination area of the substrate is: 8. The method of adjusting a substrate inspection apparatus according to claim 7, wherein the area sensor camera adjusted in the area camera adjustment step has the same relative positional relationship with respect to the belt-shaped illumination area of the substrate. In the area sensor camera adjustment step, the area sensor camera and the line sensor camera are arranged so that a photographing center of the area sensor camera is a position where the illumination intensity distribution of the belt-shaped illumination area of the substrate is maximized. A first step that is integrally moved by the camera adjustment mechanism;
A second step of moving the area camera sensor and the line sensor camera together by the camera adjustment mechanism so that the photographing center of the area sensor camera is shifted by a predetermined distance in a direction away from the illumination unit. The adjustment method for a substrate inspection apparatus according to claim 17 or 18.

Images