Wafer defect alignment device

Abstract

The utility model relates to the technical field of wafer detection, in particular to a wafer defect alignment device which comprises a base and an imaging device arranged above the base, a detection table is arranged at the center of the top of the base, an objective table is arranged at the center of the top of the detection table, and the objective table and the imaging device are located on the same center line. A fine adjustment mechanism for adjusting the angles of the objective table and the wafer is arranged in the detection table, an ejection mechanism is arranged on the inner side of the objective table, a lifting seat is arranged on the outer side of the detection table, axis lamps distributed in a cross shape are arranged at the top of the lifting seat, and an inclined lamp holder is installed in the lifting seat and close to the top end. According to the utility model, the fine adjustment mechanism drives the objective table to slightly rotate so as to adjust the placement angle of the wafer to be corresponding to the xy coordinate axis, so that the imaging device can accurately position the defect coordinate according to the coordinate system, and meanwhile, the imaging device cannot be contacted with the wafer in the adjustment process, so that the wafer can be effectively prevented from being worn or stained.

Description

Technical Field

[0001] The utility model relates to the technical field of wafer detection, in particular to a wafer defect alignment device. Background Art

[0002] During the wafer manufacturing process, when there are defects on the wafer, these defects need to be precisely located to ensure that subsequent process steps can be accurately repaired or adjusted, thereby improving the yield and performance of the wafer and reducing chip failure or reliability degradation caused by defects.

[0003] In the prior art, a wafer defect detection alignment device with publication number CN112697703A adopts a solution of "including a light source device, an image capture device, an angle rotation device, a detection platform and a motion mechanism". This solution is mainly aimed at improving the angle deviation problem during the wafer detection process. Through the angle rotation device, it can achieve the purpose of greatly improving the operating efficiency of the prior art.

[0004] However, the above scheme still has some shortcomings. For example, when the angle of the wafer is adjusted and aligned by the angle rotation device, contact and friction with the surface of the wafer will occur, which may easily cause scratches or stains on the surface of the wafer, affecting the quality of the wafer. In addition, the image capture device can only obtain images under one lighting environment. Due to the influence of light emission, some wafer defects are not easy to be found. In view of this, the utility model proposes a wafer defect alignment device. Summary of the invention

[0005] The purpose of the utility model is to provide a wafer defect alignment device, which can adjust the wafer accurately and without damage, obtain wafer images under different environments, and improve the defect detection rate, so as to solve the problems proposed in the above background technology that the wafer adjustment process is prone to friction damage and the defect image is single.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A wafer defect alignment device comprises a base and an imaging device fixedly mounted above the base, a detection platform is arranged at the top center of the base, a stage on the same center line as the imaging device is arranged at the top center of the detection platform, a control cavity is arranged on the inner side of the detection platform and near the top, a fine adjustment mechanism for adjusting the stage and the wafer angle is arranged inside the control cavity, the fine adjustment mechanism comprises micro-teeth, gears and a micro-motor coaxially driven with the gears, the micro-teeth are evenly distributed on the circumferential outer wall of the stage and mesh with the gears for transmission;

[0008] The loading platform is a hollow structure, and an ejection mechanism is provided on the inner side of the loading platform, and the ejection mechanism includes an ejection seat and a first lifting cylinder. A lifting seat is provided on the outer side of the inspection platform, and axis lights distributed in a cross shape are provided on the top of the lifting seat. An oblique lamp holder is installed inside the lifting seat and near the top.

[0009] As a preferred technical solution, the imaging device is composed of a microscope and a camera structure, and a direct light source is installed outside the lens barrel of the microscope.

[0010] As a preferred technical solution, an axis corresponding to the axis light is provided on the top of the detection platform.

[0011] As a preferred technical solution, the stage is rotatably connected to the control cavity, and two sets of inner and outer positioning grooves are provided on the top of the stage for positioning and fixing the wafer.

[0012] As a preferred technical solution, a number of evenly distributed micro-teeth are arranged on the circumferential outer wall of the stage and inside the control cavity, a gear meshing with the micro-teeth is installed on the inner side of the control cavity, and a micro-motor coaxially driven with the gear is installed inside the detection platform.

[0013] As a preferred technical solution, the ejector seat is an "H"-shaped structure, a limiting ring is fixedly provided on the base and in the lower cavity of the ejector seat, the ejector seat is slidably connected to the limiting ring, and the first lifting cylinder is arranged on the inner side of the limiting ring to push the ejector seat to move upward.

[0014] As a preferred technical solution, the inner wall of the upper cavity of the ejector seat is a fan-shaped ring surface structure, and a bottom light source is installed inside the upper cavity.

[0015] As a preferred technical solution, when the upper surface of the lifting seat is parallel to the top of the inspection platform, the light of the axis lamp forms an xy coordinate axis on the wafer, the bottom of the oblique lamp holder is a sloped structure, and the oblique lamp holder is equipped with an oblique light source set obliquely. When the oblique lamp holder is higher than the top of the inspection platform, the oblique light source performs dark field illumination on the wafer on the stage.

[0016] As a preferred technical solution, a limiting shaft is fixedly provided on the base near the lifting seat, the lifting seat is slidably connected to the limiting shaft, and storage cavities are provided on the left and right sides of the lifting seat, and a second lifting cylinder is installed inside the storage cavity.

[0017] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0018] 1. The utility model is provided with a detection table, a stage and a fine-tuning mechanism. When there is an angle error between the placement angle of the wafer sample and the moving direction of the field of view, the fine-tuning mechanism drives the stage to rotate slightly to adjust the placement angle of the wafer to correspond to the xy coordinate axis, so that the imaging device can accurately locate the defect coordinates according to the coordinate system. At the same time, during the adjustment process, no contact will occur with the wafer, which can effectively avoid wear or stains on the wafer.

[0019] 2. The utility model is provided with a lifting seat and an oblique light source. The height of the lifting seat is adjusted by a second lifting cylinder, so that the oblique light source is moved to different heights to perform dark field illumination on the wafer. By combining dark field illumination with bright field illumination, multiple groups of wafer images under different illumination conditions can be obtained, thereby improving the detection rate of wafer defects and facilitating the precise positioning of wafer defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0022] Figure 2 It is a cross-sectional view of the overall structure of the utility model;

[0023] Figure 3 This is a top view of the testing platform of the utility model;

[0024] Figure 4 This is a schematic diagram of the fine-tuning mechanism structure of the utility model;

[0025] Figure 5 This is a schematic diagram of the ejector structure of the utility model;

[0026] Figure 6 It is a schematic diagram of the lifting seat structure of the utility model.

[0027] In the figure: 1. base; 11. imaging device; 12. direct light source; 2. detection platform; 21. axis; 22. control chamber; 3. stage; 31. positioning groove; 32. micro gear; 33. gear; 34. micro motor; 4. ejector seat; 41. limiting ring; 42. first lifting cylinder; 43. bottom light source; 5. lifting seat; 51. axis lamp; 52. oblique lamp holder; 53. oblique light source; 54. limiting axis; 55. storage chamber; 56. second lifting cylinder. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] According to the attached Figure 1-6 As shown, an embodiment of the utility model provides a wafer defect alignment device, including a base 1 and an imaging device 11 fixedly installed above the base 1, a detection platform 2 is provided at the top center of the base 1, a stage 3 on the same center line as the imaging device 11 is provided at the top center of the detection platform 2, a control chamber 22 is provided on the inner side of the detection platform 2 and near the top, a fine-tuning mechanism for adjusting the stage 3 and the wafer angle is provided inside the control chamber 22, the fine-tuning mechanism includes micro-teeth 32, a gear 33 and a micro-motor 34 coaxially driven with the gear 33, the micro-teeth 32 are evenly distributed on the circumferential outer wall of the stage 3, and mesh with the gear 33 for transmission; the stage 3 is a hollow structure, an ejection mechanism is provided on the inner side of the stage 3, the ejection mechanism includes an ejection seat 4 and a first lifting cylinder 42, a lifting seat 5 is provided on the outer side of the detection platform 2, an axis lamp 51 distributed in a cross shape is provided on the top of the lifting seat 5, and an oblique lamp holder 52 is installed inside the lifting seat 5 and near the top.

[0030] An axis 21 corresponding to the axis lamp 51 is provided on the top of the detection platform 2. When the upper surface of the lifting seat 5 is parallel to the top of the detection platform 2, the light of the axis lamp 51 forms an xy coordinate axis on the wafer that coincides with the axis 21.

[0031] When performing defect detection on the wafer, the wafer to be detected is placed on the stage 3. At this time, the upper surface of the lifting seat 5 is parallel to the top of the detection platform 2, and the light of the axis lamp 51 is irradiated on the wafer to generate a visible xy coordinate axis, and the wafer image is taken by the imaging device 11. If there is an angular error between the placement angle of the wafer sample and the moving direction of the field of view, the stage 3 is driven to rotate slightly through the fine-tuning mechanism, and the placement angle of the wafer is adjusted to correspond to the xy coordinate axis, so that the imaging device 11 can accurately locate the defect coordinates according to the coordinate system. When the detection is completed, the wafer can be pushed to the top of the stage 3 through the ejection mechanism, which is convenient for subsequent wafer placement and transportation by other equipment.

[0032] As a preferred embodiment of the present invention, a control cavity 22 is provided on the inner side of the detection platform 2 and near the top, and the stage 3 is rotatably connected to the control cavity 22. Two sets of inner and outer positioning grooves 31 are provided on the top of the stage 3 for positioning and fixing the wafer. The diameters of the two sets of positioning grooves 31 are 8 inches and 12 inches respectively, corresponding to the standard size of the wafer.

[0033] As a preferred embodiment of the present invention, a plurality of evenly distributed micro-teeth 32 are provided on the circumferential outer wall of the stage 3 and inside the control cavity 22, a gear 33 meshing with the micro-teeth 32 is installed on the inner side of the control cavity 22, and a micro-motor 34 coaxially driven with the gear 33 is installed inside the detection table 2, and its model is Keshuo GM12-15BY. The step angle of the motor is 1.8° or 0.9°, and the positioning accuracy is ±5% of the step angle, which can meet the needs of high-precision rotation angle adjustment.

[0034] By driving the gear 33 to rotate through the micro motor 34 and meshing with the micro gear 32, the stage 3 can be rotated at a certain angle with high precision, so that the wafer on the stage 3 can be fine-tuned with high precision, so that the wafer sample placement angle and the moving direction of the field of view are in the same straight line, which makes it convenient for the imaging device 11 to accurately locate the defect coordinates according to the coordinate system, and during the adjustment process, there will be no contact with the wafer, which can effectively avoid wear or stains on the wafer.

[0035] As a preferred embodiment of the present invention, the ejector seat 4 is an "H"-shaped structure, a limiting ring 41 is fixedly provided on the base 1 and in the lower cavity of the ejector seat 4, the ejector seat 4 is slidably connected to the limiting ring 41, and the first lifting cylinder 42 is arranged on the inner side of the limiting ring 41, and is used to push the ejector seat 4 to move upward, so that the ejector seat 4 lifts the wafer on the stage 3 upward, and facilitates the subsequent transportation of the wafer. In addition, a flexible buffer pad is bonded and fixed to the top of the ejector seat 4 to avoid damage to the surface of the wafer.

[0036] As a preferred embodiment of the present invention, the inner wall of the upper cavity of the ejector seat 4 is a fan-shaped ring surface structure, and a bottom light source 43 is installed inside the upper cavity. The bottom light source 43 can cooperate with the direct light source 12 to perform bright field illumination on the wafer, thereby improving the clarity of the wafer and facilitating the microscope and camera structure to obtain defect images in the wafer. In addition, the fan-shaped ring surface structure outside the bottom light source 43 can enhance the diffusion effect of light to the wafer.

[0037] As a preferred embodiment of the present invention, the bottom of the oblique lamp holder 52 is a bevel structure, and the oblique lamp holder 52 is equipped with an obliquely arranged oblique light source 53. When the oblique lamp holder 52 is higher than the top of the inspection table 2, the oblique light source 53 performs dark field illumination on the wafer on the stage 3. The inclined light shines on the wafer, so that the direct light is blocked or reflected away by the object, while the scattered light or refracted light is received by the microscope objective, so that the background of the wafer appears black, and the edge or defect feature of the wafer appears bright, thereby forming a high-contrast image, which is convenient for accurately locating the defects of the wafer.

[0038] As a preferred embodiment of the present invention, a limiting shaft 54 ​​is fixedly provided on the base 1 and near the lifting seat 5, the lifting seat 5 is slidably connected to the limiting shaft 54, and a storage cavity 55 is provided on the left and right sides of the lifting seat 5, and a second lifting cylinder 56 is installed inside the storage cavity 55.

[0039] By cooperating with the second lifting cylinder 56 and the limiting shaft 54, the height of the lifting seat 5 can be adjusted, so that the oblique light source 53 can be moved to different heights to perform dark field illumination on the wafer. By combining dark field illumination with bright field illumination, multiple groups of wafer images under different illumination conditions can be obtained, which facilitates the precise positioning of wafer defects.

[0040] When the wafer defect alignment device of the utility model is used, first, the wafer is placed on the positioning groove 31, then the light of the axis lamp 51 forms an xy coordinate axis on the wafer that coincides with the axis 21, and the wafer image is photographed by the imaging device 11. If there is an angle error between the placement angle of the wafer sample and the xy coordinate axis, the micro motor 34 drives the gear 33 to rotate, so that the gear 33 and the micro gear 32 are meshed for transmission, and then the stage 3 is rotated at a certain angle with high precision, and the wafer on the stage 3 is fine-tuned with high precision to adjust the placement angle of the wafer to correspond to the xy coordinate axis;

[0041] Furthermore, the direct light source 12 and the bottom light source 43 are matched to enable the imaging device 11 to capture the wafer image under bright field illumination. After that, the second lifting cylinder 56 is used to adjust the height of the lifting base 5, so that the oblique light source 53 is moved to different heights to perform dark field illumination on the wafer, and the imaging device 11 captures the wafer image under dark field illumination, thereby obtaining multiple groups of wafer images under different illumination conditions, which facilitates accurate positioning of wafer defects.

[0042] When the wafer inspection is completed, the first lifting cylinder 42 pushes the ejector seat 4 to move upward, so that the ejector seat 4 slowly moves upward inside the stage 3 and lifts the wafer on the stage 3 upward, thereby facilitating subsequent transportation of the wafer.

[0043] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A wafer defect alignment device, comprising a base (1) and an imaging device (11) fixedly mounted above the base (1), characterized in that: A detection platform (2) is provided at the top center of the base (1); a stage (3) is provided at the top center of the detection platform (2) on the same center line as the imaging device (11); a control chamber (22) is provided on the inner side of the detection platform (2) and near the top; a fine-tuning mechanism for adjusting the angle of the stage (3) and the wafer is provided inside the control chamber (22); the fine-tuning mechanism comprises micro-teeth (32), a gear (33) and a micro-motor (34) coaxially driven with the gear (33); the micro-teeth (32) are evenly distributed on the circumferential outer wall of the stage (3) and mesh with the gear (33) for transmission; The loading platform (3) is a hollow structure. An ejection mechanism is provided on the inner side of the loading platform (3), and the ejection mechanism comprises an ejection seat (4) and a first lifting cylinder (42). A lifting seat (5) is provided on the outer side of the inspection platform (2). A cross-shaped axis lamp (51) is provided on the top of the lifting seat (5). An oblique lamp holder (52) is installed inside the lifting seat (5) and near the top.

2. The wafer defect alignment device according to claim 1, characterized in that: The imaging device (11) is composed of a microscope and a camera structure, and a direct light source (12) is installed outside the lens barrel of the microscope.

3. The wafer defect alignment device according to claim 1, characterized in that: An axis (21) corresponding to the axis light (51) is arranged on the top of the detection platform (2).

4. The wafer defect alignment device according to claim 3, characterized in that: The stage (3) is rotatably connected to the control chamber (22), and the top of the stage (3) is provided with two sets of inner and outer positioning grooves (31) for positioning and fixing the wafer.

5. The wafer defect alignment device according to claim 1, characterized in that: The ejector seat (4) is an "H"-shaped structure. A limiting ring (41) is fixedly provided on the base (1) and in the lower cavity of the ejector seat (4). The ejector seat (4) is slidably connected to the limiting ring (41). The first lifting cylinder (42) is arranged on the inner side of the limiting ring (41) and is used to push the ejector seat (4) to move upward.

6. The wafer defect alignment device according to claim 5, characterized in that: The inner wall of the upper cavity of the ejection seat (4) is a fan-shaped annular surface structure, and a bottom light source (43) is installed inside the upper cavity.

7. The wafer defect alignment device according to claim 1, characterized in that: The bottom of the oblique lamp holder (52) is an inclined surface structure, and an obliquely arranged oblique light source (53) is installed in the oblique lamp holder (52).

8. The wafer defect alignment device according to claim 7, characterized in that: A limiting shaft (54) is fixedly provided on the base (1) near the lifting seat (5), the lifting seat (5) is slidably connected to the limiting shaft (54), and a storage cavity (55) is provided on both left and right sides of the lifting seat (5), and a second lifting cylinder (56) is installed inside the storage cavity (55).

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