Wafer bonding precision detection device

Abstract

The utility model discloses a wafer bonding precision detection device, the detection device comprises a light-emitting bearing plate and a camera, the light-emitting bearing plate comprises an area light source and a bearing surface, the area light source is used for generating a light beam, and the bearing surface is used for bearing a wafer to be detected; the camera is used for capturing an image of the mark of the wafer to be detected, and the camera is located on one side of the light-emitting bearing plate and faces the bearing surface. The detection device provided by the utility model can obtain a clear mark image and has relatively high detection precision and stability.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a device for detecting wafer bonding accuracy. Background Art

[0002] In chip manufacturing, wafer bonding involves the use of chemical or physical means to tightly bond two wafers together. During this process, atoms at the bonding interface react under external forces, forming covalent bonds that fuse the two wafers together. Furthermore, this technique ensures a certain bond strength. During this process, wafer bonding alignment accuracy is a key indicator of bonding performance.

[0003] Currently, the most commonly used method for testing wafer bonding alignment accuracy is infrared light measurement. In this method, an infrared light source and camera are located on the upper and lower sides of the wafer and move synchronously, allowing the infrared light to penetrate the wafer. The camera can capture the image of the mark on the wafer. By comparing the captured mark image with a reference image, the positional deviation of the mark image can be determined, and the bonding accuracy of the wafer can be judged. However, when testing the bonding accuracy of the wafer, the wafer is usually placed on a support beam, which partially blocks the infrared light source, resulting in the possibility of unmeasurable marks. Furthermore, because part of the light source is blocked, the brightness of the measurement mark near the support beam is low, affecting the measurement results. Utility Model Content

[0004] The present application discloses a device for detecting wafer bonding precision, which is used to improve the accuracy and stability of wafer bonding precision measurement.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] In the first aspect, the present application provides a device for detecting wafer bonding accuracy, which includes a light-emitting carrier plate and a camera. The light-emitting carrier plate includes a surface light source and a carrying surface. The surface light source is used to generate a light beam, and the carrying surface is used to carry the wafer to be tested; the camera is used to capture the image of the mark on the wafer to be tested, and the camera is located on one side of the light-emitting carrier plate and facing the carrying surface.

[0007] When the wafer bonding accuracy detection device described above is used to detect the wafer bonding accuracy, the surface light source can provide uniform illumination, which can reduce image distortion caused by uneven illumination. In addition, the surface light source and the carrying device are integrated into one, which can avoid the support beam blocking the light source, and can measure all marks on the entire wafer. Moreover, the position of the surface light source and the carrying surface is fixed, and there is no need to adjust the synchronous movement of the light source and the camera, which reduces the measurement inaccuracy caused by motion errors. Therefore, the detection device in this application can obtain a clear mark image with high detection accuracy and stability.

[0008] In some embodiments, the surface light source includes a light emitting module and a light diffuser. The light diffuser is disposed on one side of the light emitting module, and a surface of the light diffuser facing away from the light emitting module serves as a bearing surface.

[0009] In some embodiments, the light diffuser contains nanoparticles.

[0010] In some embodiments, the area of ​​the light-diffusing plate is greater than or equal to the light-emitting area of ​​the light-emitting module.

[0011] In some embodiments, the light-emitting carrier plate includes a support plate, the surface light source is disposed on the support plate, and the light-emitting module is disposed between the support plate and the light-distributing plate.

[0012] In some embodiments, the support plate and the surface light source are integrally formed.

[0013] In some embodiments, the detection device further includes a driver, the light-emitting module includes a plurality of light-emitting diodes, and the driver is used to control the light-emitting intensity of the light-emitting diodes.

[0014] In some embodiments, the detection device further includes a light meter, which is used to detect the brightness of the light emitting diode.

[0015] In some embodiments, the detection device further includes a control unit, which is respectively connected to the light meter and the driver signal.

[0016] In some embodiments, the light emitting diode is an infrared light emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a wafer bonding accuracy detection device provided in an embodiment of the present application;

[0018] Figure 2 A schematic structural diagram of a light-emitting carrier plate with high wafer bonding accuracy provided in an embodiment of the present application;

[0019] Figure 3 A schematic structural diagram of a light-emitting carrier plate with high wafer bonding accuracy provided in an embodiment of the present application;

[0020] Figure 4 A process flow chart of the operation of a wafer bonding accuracy detection device provided in an embodiment of the present application.

[0021] Icon: 100 - light-emitting carrier plate; 101 - carrier surface; 110 - surface light source; 111 - light-emitting module; 111a - light-emitting diode; 112 - light-dispersing plate; 120 - support plate; 200 - camera; 300 - wafer to be tested; 400 - support beam;

[0022] 10-Mark. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two.

[0024] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0025] In the relevant detection of wafer bonding alignment accuracy, the light source and camera are respectively located on the upper and lower sides of the wafer and move synchronously so that light can penetrate the wafer, and the camera can capture the mark image on the wafer and compare the captured mark image with the reference image to determine the bonding accuracy of the wafer. Because the wafer is usually placed on a support beam, the support beam will block part of the light source, resulting in the brightness of the measurement mark near the support beam being affected, and there may be marks that cannot be measured or the accuracy of the measurement results may be affected. In addition, the light source and the camera must move synchronously, and it is difficult to calibrate the camera lens, wafer and light source to be completely parallel. When the parallelism of any two of the lens, wafer and light source is not uniform, the mark imaging quality (image size, clarity, etc.) will be inconsistent, which will affect the measurement accuracy of the wafer bonding accuracy.

[0026] In view of this, the structural diagram of a wafer bonding accuracy detection device provided in the embodiment of the present application is shown in FIG. Figure 1 The present invention provides a device for detecting wafer bonding accuracy. The device includes a light-emitting carrier plate 100 and a camera 200. The light-emitting carrier plate 100 includes a surface light source 110 and a carrying surface 101. The surface light source 110 is used to generate a light beam, and the carrying surface 101 is used to carry a wafer 300 to be tested. The camera 200 is used to capture marks on the wafer to be tested. The camera 200 is located on one side of the light-emitting carrier plate 100 and faces the carrying surface 101.

[0027] In one possible implementation, the detection device further includes a support beam 400 , which is disposed at the bottom of the light-emitting carrier board 100 , and is used to support the light-emitting carrier board 100 .

[0028] Among them, the light-emitting carrier plate 100 includes a surface light source 110 and a carrying surface 101, that is, the light-emitting carrier plate 100 can both carry the wafer to be tested and generate a light beam. The light-emitting carrier plate 100 realizes the fusion of the carrying function and the light source. The light source and the camera 200 are respectively located on the upper and lower sides of the wafer to be tested and need to move synchronously. In the detection device of the present application, only the camera 200 needs to be moved, avoiding the motion error that may occur in the synchronous movement of the light source and the camera 200, thereby improving the accuracy of the measurement. Moreover, the detection device of the present application can avoid the support beam 400 from blocking the light source, can measure all the marks on the entire wafer, and has high detection accuracy and stability.

[0029] It is understandable that the surface light source 110 may be a light emitting diode panel or a light emitting diode array, etc., and may be configured according to actual needs.

[0030] Figure 2 A schematic diagram of the structure of a light-emitting carrier plate with wafer bonding accuracy provided in an embodiment of the present application, referring to Figure 2 The surface light source 110 may include a light emitting module 111 and a light diffuser 112. The light diffuser 112 is disposed on one side of the light emitting module 111, and the surface of the light diffuser 112 facing away from the light emitting module 111 serves as the support surface 101. The light beam emitted by the light emitting module 111 is scattered and diffused by the light diffuser 112, so that the light originally concentrated at one point is evenly distributed over a larger area, thereby converting a line light source or point light source into a surface light source. This also helps to eliminate the difference in light intensity between the various light sources in the light emitting module 111, making the brightness of the entire illuminated area more consistent, thereby improving the measurement accuracy of wafer bonding precision.

[0031] In one possible implementation, the light-distributing plate 112 contains nanoparticles. The nanoparticles can scatter light, helping the light-distributing plate 112 to more effectively distribute the light evenly over the entire surface of the wafer to be tested.

[0032] The light homogenizing plate 112 may be made of glass, silicone, or polymer. When the light homogenizing plate 112 is made of polymer, the light homogenizing plate 112 may be made of polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), or polyethylene propylene.

[0033] In one possible implementation, the area of ​​the light-emitting plate 112 is greater than or equal to the light-emitting area of ​​the light-emitting module 111 to ensure higher light utilization efficiency and avoid the light at the edge of the light-emitting module 111 from being effectively guided and scattered, making the light of the entire surface light source 110 more uniform, thereby improving the overall optical effect.

[0034] It is understood that the shape of the light-dispersing plate 112 is not limited in this application, and the light-dispersing plate 112 can be circular, square or other shapes, and can be configured according to actual needs. Figure 2 As shown, the light averaging plate 112 of the detection device in this application is a circular light averaging plate.

[0035] Continue to refer to Figure 2 The light-emitting carrier plate 100 includes a support plate 120 , on which the surface light source 110 is disposed, and the light-emitting module 111 is disposed between the support plate 120 and the light-distributing plate 112 . The support plate 120 serves to support the surface light source 110 .

[0036] It is understood that the shape of the support plate 120 is not limited in this application, and the support plate 120 can be circular, square or other shapes, and can be set according to actual needs. Figure 2 As shown, the support plate 120 of the detection device in this application is circular in shape.

[0037] The support plate 120 and the surface light source 110 may be integrally formed, or they may be assembled together in other ways.

[0038] Figure 3 A schematic diagram of the structure of a light-emitting carrier plate with wafer bonding accuracy provided in an embodiment of the present application, referring to Figure 3 The detection device also includes a driver (not shown in the figure). The light-emitting module 111 includes multiple light-emitting diodes 111a. The driver is used to control the light-emitting intensity of the light-emitting diodes 111a so that the light-emitting intensity of each light-emitting diode 111a is the same, so that the light-emitting module 111 emits a uniform light beam, thereby ensuring the brightness uniformity of each position on the surface of the wafer to be tested.

[0039] The plurality of light emitting diodes 111 a may be distributed on the support plate 120 in an array, specifically a rectangular array, a triangular array, a hexagonal array, a ring array, etc.

[0040] In one possible implementation, the driver is disposed on the support plate 120 to facilitate regulation of the plurality of light emitting diodes 111 a.

[0041] In one possible implementation, the detection device further includes a light meter for detecting the brightness of the light emitting diode 111 a , wherein the light meter can be disposed outside the light emitting carrier board 100 , specifically on one side of the light emitting carrier board 100 .

[0042] In one possible implementation, the detection device further includes a control unit, which is signal-connected to the light meter and the driver. The light meter detects the intensity of each LED 111a and transmits the value to the control unit. The control unit analyzes the value and controls the driver to adjust the luminous intensity of each LED 111a to ensure that the luminous intensity of each LED 111a is consistent.

[0043] In one possible implementation, the LED 111a is an infrared LED, which emits infrared light that can penetrate the wafer 300 to illuminate the mark 10 and the surrounding area, making the mark 10 clearly visible in the camera.

[0044] When the detection device in this application is used to detect the bonding accuracy of the wafer to be tested, Figure 4 A process flow chart of a wafer bonding accuracy detection device provided in an embodiment of the present application, referring to Figure 4 , the specific steps are as follows:

[0045] 1) Placing the wafer 300 to be tested on the carrying surface 101 of the light-emitting carrying plate 100;

[0046] 2) Turning on the surface light source 110, moving the camera 200 so that the camera 200 lens is aligned with the mark 10 of the wafer 300 to be tested, and acquiring an image of the mark 10;

[0047] 3) After the measurement is completed, the wafer 300 to be tested is removed.

[0048] The detection device in the present application has simple steps when detecting the bonding accuracy of the wafer. Compared with the existing detection device that needs to move the light source and the camera 200 at the same time, the detection device in the present application only needs to move the camera 200, avoiding the motion errors that may be caused by the synchronous movement of the light source and the camera 200, thereby improving the accuracy and stability of the detection.

[0049] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations.

Claims

1. A device for detecting wafer bonding accuracy, characterized in that: include: A light-emitting carrier plate, comprising a surface light source and a carrying surface, wherein the surface light source is used to generate a light beam, and the carrying surface is used to carry a wafer to be tested; A camera is used to capture an image of the mark on the wafer to be tested, and the camera is located on one side of the light-emitting carrier plate and faces the carrier surface.

2. The detection device according to claim 1, characterized in that The surface light source includes a light emitting module and a light emitting plate. The light emitting plate is arranged on one side of the light emitting module, and the surface of the light emitting plate facing away from the light emitting module is the bearing surface.

3. The detection device according to claim 2, characterized in that The light-distributing plate contains nanoparticles.

4. The detection device according to claim 2, characterized in that The area of ​​the light-distributing plate is greater than or equal to the light-emitting area of ​​the light-emitting module.

5. The detection device according to claim 2, characterized in that The light-emitting carrier plate includes a supporting plate, the surface light source is arranged on the supporting plate, and the light-emitting module is arranged between the supporting plate and the light-distributing plate.

6. The detection device according to claim 5, characterized in that The support plate and the surface light source are integrally formed.

7. The detection device according to any one of claims 2 to 6, characterized in that: The detection device further includes a driver, the light emitting module includes a plurality of light emitting diodes, and the driver is used to control the light emitting intensity of the light emitting diodes.

8. The detection device according to claim 7, characterized in that The detection device further comprises a light meter, and the light meter is used to detect the brightness of the light emitting diode.

9. The detection device according to claim 8, characterized in that The detection device further comprises a control unit, which is respectively connected to the light meter and the driver signal.

10. The detection device according to claim 7, characterized in that: The light emitting diode is an infrared light emitting diode.

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