An apparatus for performing defect inspection on a wafer after a cutting or array process

Abstract

To provide a device for inspecting defects on a wafer subjected to a cutting or arranging process.SOLUTION: A device for inspecting defects on a wafer subjected to a cutting or arranging process is applied to inspection of the wafer. The wafer includes a silicon wafer subjected to the cutting or arranging process, and a blue film attached to a bottom of the silicon wafer. The device for inspecting the defects on the wafer subjected to the cutting or arranging process includes an infiltrate detector, a lens group, an optical lens group, a light source, a visible light camera, and an infrared camera. The infiltrate detector has a housing and a transparent cap. The liquid is so arranged as to flow and fill between the blue film and the transparent cap. The lens group is disposed below the transparent cap and within the housing. The optical lens group is disposed in the housing and below the lens group. The light source is disposed within the housing and emits visible light and infrared light. An image of the bottom of the silicon wafer is captured with the visible light camera and the infrared camera.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a wafer inspection technology, and more particularly to an apparatus for performing defect inspection by taking an image below a wafer after a cutting or arraying process is completed.

Background Art

[0002] A wafer is composed of a silicon wafer and a blue film disposed at its bottom. The wafer that needs to be inspected is a silicon wafer that is cut after being placed on the blue film or a silicon wafer that is arrayed on the blue film after being cut and forms a plurality of gaps therebetween. In particular, since the wafer after the cutting or arraying process has a plurality of gaps, quality inspection is required.

[0003] On the other hand, Patent Document 1 discloses an immersion liquid replenishing device, a replenishing method, and a wafer cutting trace inspection device provided with the immersion liquid replenishing device. Specifically, Patent Document 1 discloses that when inspecting the defective state or gap of the downward surface of the wafer from below the wafer after the cutting or arraying process is completed, an immersion liquid is injected as a medium between the blue film below the wafer and the transparent sheet of the inspection device to improve the light transmittance to the blue film, and the inspection is performed after clearly capturing an image.

[0004] In Patent Document 1, although the technique of injecting an immersion liquid as a medium between the blue film and the transparent sheet of the inspection device is disclosed, the imaging mechanism corresponding to that situation is not disclosed. Specifically, when capturing an image with visible light, since the transmittance is insufficient, the shielded part cannot be inspected. Therefore, there is a need for a technology to design a wafer that can be imaged evenly without being shielded based on the material characteristics of the wafer.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The main object of the present invention is to provide an apparatus (wafer inspection apparatus) for performing defect inspection on a wafer after the cutting or arraying process is completed. The apparatus for performing defect inspection on a wafer after the cutting or arraying process is completed incorporates an immersion liquid detector and captures an image of the bottom surface of the wafer from below the wafer with visible light and infrared light, and reaches a complete inspection result by inspecting.

Means for Solving the Problems

[0007] To solve the above-mentioned problems, an apparatus for performing defect inspection on a wafer after the cutting or arraying process is completed is applied to the inspection of wafers. The wafer has a silicon wafer after the cutting or arraying process is completed and a blue film attached to the bottom of the silicon wafer. The apparatus for performing defect inspection on a wafer after the cutting or arraying process is completed includes an immersion liquid detector, a lens group, an optical Element group, a light source, a visible light camera, and an infrared camera. The immersion liquid detector has a housing and a transparent cap. The housing has a perforation at the top. The perforation is shielded by the transparent cap. The transparent cap is installed below the blue film and at a predetermined distance from the blue film. The liquid flows and is arranged to fill between the blue film and the transparent cap. The lens group is arranged below the transparent cap and inside the housing. Optical Element group is arranged inside the housing and below the lens group. The light source is arranged inside the housing, and opticalElement It emits visible light and infrared rays to the outside through a group, a lens group, and a transparent cap. The visible light camera is disposed within the housing, and captures an image after capturing the visible light entering the housing from the outside with an optical Element group. The infrared camera is disposed within the housing, and captures an image after capturing the infrared rays entering the housing from the outside with an optical Element group.

[0008] Specifically, the present invention incorporates an immersion liquid detector, captures an image of the bottom surface of the wafer from below the wafer with visible light and infrared rays, and reaches a complete inspection result by generating images of different depths with visible light having low transmittance to the wafer and infrared rays having high transmittance to the wafer.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0010] Hereinafter, with reference to the drawings, an apparatus for performing a defect inspection on a wafer after a cutting or arranging process according to the present invention will be described in detail.

[0011] (First Embodiment) A description will be given with reference to FIGS. 1 to 3. The apparatus 10 for inspecting a wafer after the cutting or arranging process according to the first embodiment is applied to the inspection of the wafer 91 after the cutting or arranging process. The wafer 91 has a silicon wafer 92 after the cutting or arranging process, a blue film 94 attached to the bottom of the silicon wafer 92, and a plurality of gaps 921 formed in the silicon wafer 92 by the cutting or arranging process. The apparatus 10 for inspecting a wafer after the cutting or arranging process includes an immersion liquid detector 11, a lens group (lens unit) 21, an optical Element group 31, a light source 41, a visible light camera 51, and an infrared camera 61.

[0012] The immersion liquid detector 11 has a housing 12 and a transparent cap 16. The housing 12 has a perforation 14 at the top. The perforation 14 is shielded by the transparent cap 16. When performing the inspection, the transparent cap 16 is arranged below the blue film 94 and at a predetermined distance from the blue film 94. A liquid (not shown in the figure) flows and is arranged to fill between the blue film 94 and the transparent cap 16. It is a well-known technique that the immersion liquid detector 11 has a function of filling and recovering the immersion liquid. Since it is also a well-known technique that the liquid serving as the medium flows and fills between the blue film 94 and the transparent cap 16, the description thereof is omitted in this embodiment by the drawings or the description.

[0013] The lens group 21 is arranged below the transparent cap 16 and inside the housing 12.

[0014] Optical Element The group 31 is arranged inside the housing 12 and below the lens group 21. In the first embodiment, the optical Element group 31 has a half mirror 32 and a spectroscopic mirror 34. The half mirror 32 reflects a part of the light rays from the light source 41 to the lens group 21 and allows the other part to pass through. The light rays entering from the outside hit the half mirror 32 after passing through the transparent cap 16 and the lens group 21. Then, a part of the light rays passes through the half mirror 32 and hits the beam splitter mirror 34. The beam splitter mirror 34 allows visible light to pass through and reflects infrared light.

[0015] The light source 41 is arranged inside the housing 12. In this embodiment, a halogen lamp that emits visible light and infrared light is adopted. The halogen lamp emits visible light and infrared light to the outside through the optical Element group 31, the lens group 21, and the transparent cap 16. The light source 41 is not limited to a halogen lamp, and it may be a mixed light source of an infrared light emitting diode and a visible light emitting diode.

[0016] The visible light camera 51 is arranged inside the housing 12. It captures the visible light entering the housing 12 from the outside with the optical lens 31 and then takes an image. Specifically, the visible light camera 51 captures the visible light that has passed through the beam splitter mirror 34 and is directed towards the beam splitter mirror 34, and then takes an image.

[0017] The infrared camera 61 is arranged inside the housing 12. It captures the infrared light entering the housing 12 from the outside with the optical lens 31 and then takes an image. Specifically, the infrared camera 61 captures the infrared light that has bounced off the beam splitter mirror 34 and is directed towards the beam splitter mirror 34, and then takes an image.

[0018] The visible light camera 51 and the infrared camera 61 each have tube lenses 52, 62. Since the light rays that have bounced off the beam splitter mirror 34 or passed through the beam splitter mirror 34 are captured by the tube lenses 52, 62 and then an image is taken, the aiming function can be improved. The magnification of the tube lenses 52, 62 is determined by the professional knowledge of the merchant.

[0019] The above is the description of the structure of the first embodiment. Subsequently, the usage method of the first embodiment will be elucidated.

[0020] This will be described with reference to FIG. 2. Before taking an image, a liquid (not shown in the figure) is filled and flowed between the blue film 94 at the bottom of the wafer 91 and the transparent cap 16. When the refractive index of the liquid is similar to that of the transparent cap 16, the refraction of light can be significantly reduced, and a clearer image can be captured than when there is no liquid. That is, since the prior art is disclosed by Patent Document 1, it is not shown in the drawings.

[0021] When taking an image, the visible light and infrared rays from the light source 41 are reflected by the half mirror 32, a part of which is emitted to the outside through the lens group 21 and the transparent cap 16, and then passes through the blue film 94 and hits the bottom surface of the silicon wafer 92 and bounces back. When the bounced light rays pass through the transparent cap 16 and the lens group 21, and then pass through the half mirror 32 and hit the spectroscopic mirror 34, the visible light camera 51 and the infrared camera 61 can capture the visible light and infrared rays by the spectroscopic mirror 34 and take an image.

[0022] This will be described with reference to FIGS. 2 and 3. Infrared rays have a relatively high permeability to the silicon wafer 92, while visible light has a relatively low permeability to the silicon wafer 92. When taking an image, an image is taken of the bottom surface of the silicon wafer 92 by the reflection of visible light, and an image can be taken by the infrared rays hitting the bottom surface of the silicon wafer 92 and partially passing through the bottom surface of the silicon wafer 92. Since the permeability of infrared rays is higher than that of visible light, the infrared image captured by the infrared camera 61 includes a part of the bottom surface and a deep part inside the silicon wafer 92. Specifically, when taking an image of the gap 921 formed in the silicon wafer 92 during the cutting process, the infrared image captured by the infrared camera 61 includes the states of both side wall surfaces of the gap 921 in the silicon wafer 92. By combining the image captured by the visible light camera 51 and the image captured by the infrared camera 61, it is possible to compare and determine, using image processing technology, whether there are any abnormalities or missing parts at the edges of the gap 921 formed in the silicon wafer 92 by the cutting process.

[0023] As described above, the present invention incorporates the immersion liquid detector 11 and captures an image of the bottom surface of the wafer 91 from below the wafer 91 using visible light and infrared light to obtain a complete inspection result.

[0024] This will be described with reference to FIG. 4. The present invention is optical Element Add a reflection mirror 36 to the optical group 31. The reflection mirror 36 reflects the infrared light bounced back from the spectroscopic mirror 34 at another angle, and can change the shooting directions of the infrared camera 61 and the visible light camera 51 from a perpendicular state to a parallel state. In addition, an autofocus laser 71 is added into the housing 12 to meet the needs of autofocus. The laser from the autofocus laser 71 hits the laser spectroscopic mirror 72 and bounces back to the transparent lens. Visible light and infrared light can pass through the laser spectroscopic mirror 72. Summarizing the above, adding the autofocus laser 71 and the laser spectroscopic mirror 72 can provide autofocus without affecting the irradiation of visible light and infrared light or the taking of images.

[0025] In this embodiment, since the visible light camera 51 cannot catch infrared light, if a half mirror is used instead of the spectroscopic mirror 34 in the optical group 31, part of the light hits the half mirror and bounces back, and another part passes through the half mirror. Element ​If the light rays reflected by hitting the half mirror or the light rays passing through the half mirror enter the visible light camera 51, it is possible to capture only the visible light and take an image. If the light rays reflected by hitting the half mirror or the light rays passing through the half mirror enter the infrared camera 61, it is possible to capture only the infrared rays and take an image. Since the method described above can be understood with reference to FIGS. 1 and 2, the drawings and detailed description are omitted.

[0026] (Second Embodiment) FIG. 5 is a cross-sectional view showing an apparatus 10' for performing a defect inspection on a wafer after the cutting or arranging process according to the second embodiment of the present invention. The difference from the first embodiment is as follows.

[0027] The second embodiment further includes an upper light source 81'. The upper light source 81', that is, the halogen lamp, is installed above the wafer 91 and emits visible light and infrared light. The upper light source 81' irradiates the lower transparent cap 16' and the lens group 21 with light rays. The upper light source 81' is not limited to a halogen lamp, and may be a mixed light source of an infrared light emitting diode and a visible light emitting diode.

[0028] As shown in FIGS. 5 and 6, when performing the inspection, the light rays from the upper light source 81' hit the gap 921 formed in the silicon wafer 92 by the cutting process. The light rays passing through the gap 921 become the backlight of the visible light camera 51' and the infrared camera 61. When taking an image in the backlight mode, if the light source 41' is shut down and the upper light source 81' is activated, it is possible to capture the visible light and infrared light separately in the backlight mode and take a backlight image. When taking only the backlight image in visible light, instead of using the halogen lamp, the visible light source can be directly used as the upper light source 81'. When taking only the backlight image in infrared light, the infrared light source can be directly used as the upper light source 81'.

[0029] Since the other technical features and achieved effects of the second embodiment are the same as those of the first embodiment, the description thereof is omitted in this example.

[0030] As described above, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the invention.

Explanation of Reference Numerals

[0031] 10, 10': Apparatus for performing defect inspection on a wafer after the cutting or arraying process 11: Infiltrating liquid detector 12: Housing 14: Perforation 16, 16': Transparent cap 21, 21': Lens group 31: Optical Element Group 32: Half mirror 34: Beam splitter mirror 36: Reflecting mirror 41, 41': Light source 51, 51': Visible light camera 52: Tube lens 61, 61': Infrared camera 62: Tube lens 71: Auto-focus laser 72: Laser beam splitter mirror 81': Upper light source 91: Wafer 92: Silicon wafer 921: Gap 94: Blue film

Claims

1. An apparatus for inspecting a wafer after a cutting or arranging process, the apparatus being applied to inspecting a wafer and including an infiltrating liquid detector, a lens group, an optical element group, a light source, a visible light camera, and an infrared camera, the apparatus comprising: The wafer includes a silicon wafer that has been cut or aligned, and a blue film attached to the bottom of the silicon wafer; the infiltration liquid detector has a housing and a transparent cap, the housing has a perforation at an upper portion, the perforation is covered by the transparent cap, the transparent cap is placed below the blue film and at a predetermined distance from the blue film, A liquid is arranged between the blue film and the transparent cap so as to flow and fill the space between the blue film and the transparent cap, the lens group is disposed below the transparent cap and within the housing; the optical element group is disposed within the housing and below the lens group; the light source is disposed within the housing and emits visible light and infrared light to the outside via the optical element group, the lens group and the transparent cap; the visible light camera is disposed within the housing, and captures visible light entering the housing from the outside using the optical element group to take an image; The infrared camera is disposed within the housing, and infrared light entering the housing from the outside is captured by the optical element group and an image is taken.

2. the optical element group includes a half mirror and a spectroscopic mirror, the half mirror reflecting a part of the light beam from the light source to the lens group and allowing the remaining part to pass through; A light ray coming from the outside passes through the transparent cap and the lens group and strikes the half mirror, and then a part of the light ray passes through the half mirror and strikes the spectroscopic mirror, 2. An apparatus for performing defect inspection on a wafer after a cutting or alignment process as described in claim 1, wherein the spectroscopic mirror passes visible light or infrared light, reflects another visible light or infrared light, and causes the visible light camera to capture the visible light and the infrared camera to capture the infrared light.

3. 3. An apparatus for performing defect inspection on a wafer after a cutting or alignment process as described in claim 2, characterized in that the group of optical elements further includes a reflecting mirror, which reflects the light beam reflected from the spectroscopic mirror at a different angle to change the direction of irradiation.

4. the optical element group includes two half mirrors, one of which reflects a portion of the light beam from the light source to the lens group and transmits the remaining portion; A light ray coming from the outside passes through the transparent cap and the lens group and hits the half mirror, and then a part of the light ray passes through the half mirror and hits another half mirror, 2. An apparatus for inspecting defects on a wafer after a cutting or alignment process as described in claim 1, wherein another of the half mirrors reflects a portion of the light beam and transmits another portion of the light beam, and causes the reflected or transmitted light beam to be captured by the visible light camera and the other reflected or transmitted light beam to be captured by the infrared camera.

5. 5. An apparatus for performing defect inspection on a wafer after a cutting or alignment process as described in claim 4, characterized in that the group of optical elements further includes a reflecting mirror, which reflects the light beam reflected from another of the half mirrors at a different angle to change the direction of irradiation.

6. 2. The apparatus for inspecting defects on a wafer after a cutting or arrangement process according to claim 1, wherein the light source is a halogen lamp.

7. It also has an upper light source, 2. The apparatus for inspecting defects on a wafer after a cutting or alignment process as described in claim 1, wherein the upper light source is placed above the wafer and irradiates light onto the transparent cap and the lens group below, the light including visible light and infrared light or only visible light.

8. 8. The apparatus for inspecting defects on a wafer after a cutting or arranging process according to claim 7, wherein the upper light source is a halogen lamp.

9. It also has an autofocus laser, the autofocus laser is disposed within the housing; The laser from the autofocus laser hits the laser spectroscopic mirror and bounces back to the lens group, 2. The apparatus for inspecting defects on a wafer after a cutting or arranging process according to claim 1, wherein the laser spectroscopic mirror transmits visible light and infrared light.

10. 2. The apparatus for performing defect inspection on a wafer after a cutting or alignment process as described in claim 1, wherein the visible light camera and the infrared camera each capture a light beam reflected from the optical element group or a light beam passing through the optical element group by a tube lens and then take an image.

Images