Wafer defect detection path planning method, detection system and computing equipment
By collecting the height value of the wafer edge in the wafer detection system and planning the detection path, using the mid-perpendicular line as the detection path, the problem of excessive z-axis movement of the optical system during high-speed detection is solved, and high-precision wafer defects are achieved Test.
Patent Information
- Application Number
- CN202411360589.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-01-03
AI Technical Summary
During high-speed detection, after the displacement stage carrying the wafer moves, the optical system needs to move the z-axis greatly, resulting in the image being prone to dummy and black images.
Move the wafer to be tested through the XY mobile platform, collect the height values of the four preset sampling points evenly distributed on the edge, obtain the mid-perpendicular line of the connection between the two top-ranked points as the detection path, and control the common light path The optical module moves along the X-axis and Y-axis to reduce the height variation of the z-axis.
It effectively avoids the situation of dummy and black images of the image, improves detection accuracy and efficiency, and reduces equipment costs.
Smart Images
Figure CN119245653A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor wafer defect detection, and in particular to a wafer defect detection path planning method, a detection system and a computing device. Background Art
[0002] In the process of integrated circuit chip manufacturing, product yield is an important indicator to measure the chip manufacturing process. As the key chip size continues to shrink and the pattern density continues to increase, the defect size that affects the yield is also shrinking, and the difficulty of controlling the chip manufacturing process is increasing. The widespread use of new three-dimensional device structures and new semiconductor materials such as copper interconnects, low-k and high-k dielectric materials, and metal gate electrodes has brought new electrical performance defect problems; new process flows have also brought new process defects. The presence of wafer defects may cause abnormal operation of the device and become an important factor affecting the yield. Improving the manufacturing process and increasing the chip yield have put forward higher requirements on the accuracy and detection capability of the detection equipment.
[0003] High-speed and high-precision fully automatic intelligent control systems are one of the key technologies in modern industry, manufacturing and many high-tech fields. This system can achieve a defect resolution of 0.2-0.4 microns and an eight-inch wafer detection speed of more than one wafer per hour. Because the high numerical aperture optical system used in the high-precision defect detection system has a depth of field of less than 1 micron; and after each process, the surface of the wafer will be uneven, with a height difference of tens of microns. In this way, during high-speed detection, after the translation stage carrying the wafer moves, the optical system needs to move significantly on the z-axis in order to achieve focusing, which makes the image acquired by the optical system prone to out-of-focus and black images.
[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention
[0005] In order to overcome the technical problem that during high-speed detection, after the translation stage carrying the wafer moves, the optical system needs to move significantly on the z-axis to achieve focusing, which causes the image acquired by the optical system to be easily out of focus or black, the present invention provides a wafer defect detection path planning method, detection system and computing device.
[0006] In a first aspect, in order to solve the above technical problems, the present invention provides a wafer defect detection path planning method, comprising:
[0007] The wafer to be tested is moved by an XY moving platform until the height values at at least four preset sampling points on the edge of the wafer to be tested are collected by the common optical path optical module; wherein the XY moving platform is used to place the wafer to be tested, and each preset sampling point is evenly distributed on the edge of the wafer to be tested;
[0008] Arrange each height value in order and obtain the top two preset sampling points;
[0009] Obtaining a line connecting the two preset sampling points, and drawing a perpendicular bisector of the line, and obtaining two intersection points where the perpendicular bisector of the line intersects with the edge of the wafer to be measured;
[0010] The line between the two preset sampling points is used as the X-axis, the line between the two intersection points is used as the Y-axis, and one of the intersection points is used as the starting point and the other intersection point is used as the final point;
[0011] The common light path optical module is controlled to start shooting from the starting point, and the detection path of the XY mobile platform is planned through the X-axis and the Y-axis until the common light path optical module shoots an image of the final point.
[0012] In a second aspect, in order to solve the above technical problems, the present invention provides a wafer defect detection system, comprising: a gantry, a Z-axis moving stage, a common light path optical module, an XY moving platform and an industrial computer; wherein the Z-axis moving stage is installed on the gantry, and the common light path optical module is installed below the Z-axis moving stage; the XY moving platform is arranged below the common light path optical module; the Z-axis moving stage, the common light path optical module and the XY moving platform are all connected to the industrial computer for communication;
[0013] The common optical path optical module is used to collect images of each test point of the wafer to be tested, and transmit each image to the industrial computer;
[0014] The Z-axis moving stage is used to move the position of the common light path optical module along the Z-axis direction based on the real-time focusing condition of the common light path optical module;
[0015] The XY moving platform is used to place the wafer to be tested;
[0016] The industrial computer is used to implement a wafer defect detection path planning method as described above, and control the operation of the XY mobile platform based on the planned detection path.
[0017] In the third aspect, in order to solve the above-mentioned technical problems, the present invention provides a computing device, including a memory, a processor, and a program stored in the memory and running on the processor, and when the processor executes the program, it implements the steps of a wafer defect detection path planning method as described above.
[0018] The beneficial effect of the present invention is that the wafer to be tested is moved by an XY moving platform, so that the height values at at least four preset sampling points evenly distributed on the edge of the wafer to be tested are collected by the common optical path optical module, and the two preset sampling points with the highest height values are obtained. After the wafer is processed, the typical surface unevenness is flat at one end and warped at the other end. The two preset sampling points with the highest ranking are usually at the flat end of the wafer or at the warped end of the wafer. The height difference in the direction of the line connecting the two preset sampling points is small, and the perpendicular midline of the line is usually in the direction from the flat end to the warped end, or in the direction from the warped end to the flat end, and the height difference is large. Therefore, the perpendicular midline of the line connecting the two preset sampling points with the highest height values is obtained, and the two intersection points of the perpendicular midline and the edge of the wafer to be tested are determined as the starting point and the end point. In this way, the line between the two preset sampling points with the highest height values is used as the X-axis, and the line between the starting point and the end point is used as the Y-axis. The common optical path optical module is controlled to start shooting from the starting point, and the detection path of the XY mobile platform is planned through the X-axis and Y-axis. During high-speed detection, after the XY translation stage carrying the wafer to be tested moves, when the common optical path optical module shoots the image of the wafer to be tested along the X-axis, the height change along the Z-axis is small, so that the acquired image is not prone to out-of-focus or black images. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 A flow chart of a wafer defect detection path planning method provided by the present invention;
[0020] Figure 2 A schematic diagram of an embodiment provided by the present invention;
[0021] Figure 3 The present invention provides a structural schematic diagram of a wafer defect detection system;
[0022] Figure 4 A specific structural schematic diagram of a wafer defect detection system is provided for the present invention. DETAILED DESCRIPTION
[0023] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0024] The following describes a wafer defect detection path planning method, a detection system, and a computing device according to an embodiment of the present invention in conjunction with the accompanying drawings.
[0025] Combination Figure 1 As shown, the embodiment of the present disclosure provides a wafer defect detection path planning method, comprising:
[0026] Step S101, moving the wafer to be tested by an XY moving platform until the height values at at least four preset sampling points on the edge of the wafer to be tested are collected by the common optical path optical module. The XY moving platform is used to place the wafer to be tested, and each preset sampling point is evenly distributed on the edge of the wafer to be tested. The height value represents the height distance between the preset sampling point and the plane on which the wafer to be tested is placed.
[0027] In some embodiments, the height values at at least four preset sampling points on the edge of the wafer to be tested are collected in the following manner: the wafer to be tested is moved by an XY moving platform until the height value of any point on the edge of the wafer to be tested is collected by the common light path optical module, and this point is used as the first preset sampling point. The second point on the edge of the wafer to be tested that is symmetrical to the center of the first preset sampling point is used as the second preset sampling point. The line between the first preset sampling point and the second preset sampling point is obtained, and a perpendicular midline is made. The two intersection points of the perpendicular midline and the edge of the wafer to be tested are used as the third preset sampling point and the fourth preset sampling point. The wafer to be tested is then moved by the XY moving platform until the height values of the second preset sampling point, the third preset sampling point, and the fourth preset sampling point are collected by the common light path optical module.
[0028] It is understandable that the number of preset sampling points collected on the edge of the wafer to be tested may be 6, 8, etc., and the preset sampling points may be evenly distributed on the edge of the wafer to be tested.
[0029] Step S102, arranging the height values in order, and obtaining the top two preset sampling points.
[0030] Specifically, each height value is arranged in ascending order, or each height value is arranged in descending order, and two preset sampling points with the highest ranking are obtained.
[0031] Step S103, obtaining a line connecting two preset sampling points, and drawing a perpendicular bisector of the line, and obtaining two intersection points where the perpendicular bisector of the line intersects with the edge of the wafer to be measured.
[0032] Combination Figure 2 As shown, Figure 2 An embodiment is provided. Figure 2 The wafer to be tested is included in the sample. In this embodiment, the height values of the preset sampling points are arranged in ascending order, and the top two preset sampling points, preset sampling point A and preset sampling point B (i.e., the two preset sampling points with the lowest height values) are selected. The connecting line between the preset sampling point A and the preset sampling point B is obtained, and the perpendicular midline of the connecting line is drawn to obtain two intersection points where the perpendicular midline of the connecting line intersects with the edge of the wafer to be tested, i.e., the intersection point A and the second intersection point B.
[0033] Step S104: take the line between the two preset sampling points as the X-axis, take the line between the two intersection points as the Y-axis, and take one of the intersection points as the starting point and the other intersection point as the final point.
[0034] Step S105 , controlling the common light path optical module to start shooting from the starting point, and planning the detection path of the XY mobile platform through the X-axis and the Y-axis, until the common light path optical module captures the image of the final point.
[0035] A wafer defect detection path planning method provided by an embodiment of the present disclosure is adopted, and the wafer to be tested is moved by an XY moving platform, so that the height values at at least four preset sampling points evenly distributed on the edge of the wafer to be tested are collected by the common optical path optical module, and the two preset sampling points with the highest height values are obtained. After the wafer is processed, the typical surface unevenness is flat at one end and warped at the other end. The two preset sampling points with the highest ranking are usually at the flat end of the wafer or at the warped end of the wafer. The height difference in the direction of the line connecting the two preset sampling points is small, and the perpendicular midline of the line is usually in the direction from the flat end to the warped end, or in the direction from the warped end to the flat end, and the height difference is large. Therefore, the perpendicular midline of the line connecting the two preset sampling points with the highest height values is obtained, and the two intersection points of the perpendicular midline and the edge of the wafer to be tested are determined as the starting point and the end point. In this way, the line between the two preset sampling points with the highest height values is used as the X-axis, and the line between the starting point and the end point is used as the Y-axis. The common optical path optical module is controlled to start shooting from the starting point, and the detection path of the XY mobile platform is planned through the X-axis and Y-axis. During high-speed detection, after the XY translation stage carrying the wafer to be tested moves, when the common optical path optical module shoots the image of the wafer to be tested along the X-axis, the height change along the Z-axis is small, so that the acquired image is not prone to out-of-focus or black images.
[0036] Preferably, the height values at at least four preset sampling points on the edge of the wafer to be tested are collected by the common optical path optical module, including: focusing on each preset sampling point by the common optical path optical module to obtain focus instruction information; wherein the focus instruction information represents the distance information that needs to be adjusted when the ATF unit of the common optical path optical module instructs the array camera of the common optical path optical module to clearly image the photographed object. Obtain the focal length of the objective lens of the common optical path optical module. Based on the focus instruction information and the focal length of the objective lens corresponding to each preset sampling point, determine the distance value between each preset sampling point and the objective lens. Determine the height value at each preset sampling point based on each distance value.
[0037] Among them, the autofocus (Autofocus Through Focus, ATF). The focus instruction information refers to the focus instruction information when the common light path optical module captures the image of the preset sampling point and makes the photographed object clearly imaged. In this way, the distance value between each preset sampling point can be determined by the focus instruction information and the focal length of the objective lens. It is convenient to determine the height value at the preset sampling point according to each distance value.
[0038] In addition, the existing autofocus unit is used to obtain the height value at each preset sampling point of the wafer to be tested, without introducing additional equipment, which can reduce equipment costs.
[0039] Specifically, the distance between each preset sampling point and the objective lens is calculated by the following formula: H=delta(x)+focal length of the objective lens, wherein H is the distance between the preset sampling point and the objective lens; delta(x) is the focus instruction information.
[0040] Preferably, determining the height value at each preset sampling point based on each distance value includes: obtaining the height value of the objective lens when the common optical path optical module focuses on each preset sampling point, and subtracting the height value of the objective lens from each distance value to determine the height value at each preset sampling point.
[0041] Since the common light path optical module moves along the Z axis when focusing and shooting at each preset sampling point in order to make the photographed object clearly imaged, the common light path optical module makes the height of the objective lens of the common light path optical module different. Therefore, by subtracting the objective lens height value corresponding to the same preset sampling point from the distance value, the height distance between the preset sampling point and the plane on which the wafer to be tested is placed can be obtained, that is, the height value at each preset sampling point can be obtained.
[0042] Preferably, the common light path optical module is controlled to start shooting from the starting point, and the detection path of the XY mobile platform is planned through the X-axis and the Y-axis until the common light path optical module captures the image of the final measurement point, including: controlling the common light path optical module to start shooting from the starting point, and controlling the XY mobile platform to move periodically along a preset path until the common light path optical module captures the image of the final measurement point. The preset path includes: controlling the XY mobile platform to move along the positive direction of the X-axis until the common light path optical module captures the image of the edge of the wafer to be measured; controlling the XY mobile platform to move a preset distance along the positive direction of the Y-axis, and then moving along the reverse direction of the X-axis until the common light path optical module captures the image of the edge of the wafer to be measured. Among them, the positive direction of the Y-axis is the direction from the starting point to the final measurement point. Control the XY mobile platform to move a preset distance along the positive direction of the Y-axis. Among them, the image of the edge of the wafer to be measured captured by the common light path optical module refers to the image of the edge position of the wafer to be measured in the moving direction captured by the common light path optical module.
[0043] In this way, when the XY moving platform is controlled to move along the positive direction of the X-axis or the negative direction of the X-axis, the distance moved by the common light path optical module in the Z-axis direction is smaller and the moving time is also shorter, so that the common light path optical module has enough time to focus to make the image of the photographed object clear and avoid the image being out of focus or black. When the XY moving platform is controlled to move along the positive direction of the Y-axis, although a large height difference may occur, the preset distance moved in the positive direction of the Y-axis is smaller, the frequency of the height difference is lower, and it will not affect the common light path optical module when it moves along the positive direction of the X-axis or the negative direction of the X-axis. It can have enough time to focus to make the image of the photographed object clear. This can further reduce the situation where the image is out of focus or black.
[0044] It can be understood that the preset distance is the Y-axis distance of the shooting field of view of the common light path optical module. For example, the shooting field of view of the common light path optical module is a rectangle, the long side of the rectangle is parallel to the X-axis and has a length of a, and the short side of the rectangle is parallel to the Y-axis and has a length of b. Then, the Y-axis distance of the shooting field of view is b length. That is, the common light path optical module is controlled to move along the Y-axis direction by b length.
[0045] It is understandable that since the position of each wafer to be tested on the XY mobile platform is different, the X-axis (the line connecting the top two preset sampling points) and Y-axis (the line connecting the two intersection points) pointed to by each wafer to be tested are different. Therefore, if the X-axis and Y-axis of the XY mobile platform are adjusted according to the actual situation of each wafer to be tested, the technician needs to recompile the program of the XY mobile platform, which will take a long time. Therefore, after determining the X-axis and Y-axis that each wafer to be tested points to, the wafer to be tested can be rotated so that the X-axis and Y-axis it points to correspond to the X-axis and Y-axis preset by the XY mobile platform itself. Thereby, the wafer to be tested can be tested more quickly.
[0046] In addition, since the edge of the wafer to be tested does not actually need to be monitored when defect detection is performed on the wafer to be tested, in order to ensure that the detection range of the wafer to be tested can be fully covered, this embodiment chooses to use the common optical path optical module to capture the edge of the wafer to be tested as the trigger condition for the XY moving platform to stop moving in the positive direction of the X-axis or the reverse direction of the X-axis.
[0047] Combination Figure 3As shown, the embodiment of the present disclosure provides a wafer defect detection system, including: a gantry 1, a Z-axis moving table 2, a common light path optical module 3, an XY moving platform 4 and an industrial computer (not shown). Among them, the Z-axis moving table is installed on the gantry, and the common light path optical module is installed on the Z-axis moving table; the XY moving platform is arranged below the common light path optical module; the Z-axis moving table, the common light path optical module and the XY moving platform are all communicatively connected with the industrial computer. The common light path optical module is used to collect images of each test point of the wafer to be tested, and transmit each image to the industrial computer. The Z-axis moving table is used to move the position of the common light path optical module along the Z-axis direction based on the real-time focusing status of the common light path optical module. The XY moving platform is used to place the wafer to be tested. The industrial computer is used to implement a wafer defect detection path planning method as claimed in claim 1, and control the operation of the XY moving platform based on the planned detection path.
[0048] A wafer defect detection system provided by an embodiment of the present disclosure is adopted. The industrial computer controls the XY mobile platform to move the wafer to be tested, so that the industrial computer collects the height values at at least four preset sampling points evenly distributed on the edge of the wafer to be tested through the common optical path optical module, and obtains the two preset sampling points with the highest height values. After the wafer is processed, the typical surface unevenness is flat at one end and tilted at the other end. The two preset sampling points with the highest ranking are usually at the flat end of the wafer or at the tilted end of the wafer. The height difference in the direction of the connection line between the two preset sampling points is small, and the perpendicular midline of the connection line is usually in the direction from the flat end to the tilted end, or in the direction from the tilted end to the flat end, and the height difference is large. Therefore, the perpendicular midline of the connection line between the two preset sampling points with the highest height values is obtained, and the two intersection points of the perpendicular midline and the edge of the wafer to be tested are determined as the starting point and the end point. In this way, the industrial computer uses the line between the two preset sampling points with the highest height values as the X-axis, and the line between the starting point and the end point as the Y-axis, controls the common optical path optical module to start shooting from the starting point, and plans the detection path of the XY mobile platform through the X-axis and Y-axis. When the wafer defect detection system performs high-speed detection, after the XY translation stage carrying the wafer to be tested moves, when the common optical path optical module shoots the image of the wafer to be tested along the X-axis, the height change along the Z-axis is small, so that the acquired image is not prone to out-of-focus or black images.
[0049] In addition, through path planning, the Z-axis movement time of the common optical path optical module is also reduced, which can improve the detection efficiency and quality, thereby increasing the throughput of the wafer defect detection system and improving the economic benefits of the factory.
[0050] Specifically, the XY moving platform is installed on a marble platform, and the marble platform is arranged below the gantry.
[0051] Preferably, combined Figure 3 and Figure 4As shown, the common optical path optical module includes an ATF unit 5 and an area array camera 6. The ATF unit 5 and the area array camera 6 are both connected to the industrial computer 10 for communication. The area array camera is used to automatically focus on each sampling point through the ATF unit, obtain the focused image, and transmit the image to the industrial computer.
[0052] In this way, the area array camera uses the focus status of the ATF unit to perform automatic focusing, and can quickly capture clear images, which is convenient for ensuring the inspection efficiency and quality of the wafer defect system.
[0053] Specifically, the ATF unit is used to perform automatic focusing, and send focus instruction information directed by the automatic focusing to the industrial computer, and the industrial computer controls the area array camera to focus based on the focus instruction information.
[0054] Preferably, see again Figure 3 and Figure 4 , the Z-axis moving stage includes a stepper motor 7 and a piezoelectric displacement stage 8. Among them, the stepper motor 7 is installed on the gantry 1, the piezoelectric displacement stage 8 is installed on the stepper motor 1, and the common optical path optical module (ATF unit 5 and array camera 6) is installed on the piezoelectric displacement stage; the stepper motor and the piezoelectric displacement stage are both connected to the industrial control computer for communication. The industrial control computer is also used to control the stepper motor to move along the Z-axis direction before the common optical path optical module detects the starting point, until the moving range of the piezoelectric displacement stage meets the focusing requirement of the optical path optical module for the starting point; and, when the XY moving platform is controlled to move along the positive direction of the X-axis or the reverse direction of the X-axis, the piezoelectric displacement stage is controlled to move along the Z-axis direction based on the real-time focusing situation of the common optical path optical module; and, when the XY moving platform is controlled to move along the positive direction of the Y-axis, the stepper motor is controlled to move along the Z-axis direction until the moving range of the piezoelectric displacement stage meets the focusing requirement of the common optical path optical module for the current point to be measured.
[0055] The test points are points on the wafer to be tested, and the common optical path optical module needs to photograph all the test points on the wafer to be tested, so that the industrial computer can determine the defect status of the wafer to be tested based on the photographed images.
[0056] The moving range of the stepper motor is relatively large, and it is mainly used to control the common optical path optical module to move in large amplitude on the Z axis. The moving range of the piezoelectric displacement stage is relatively small, about a few microns, and it is mainly used to control the common optical path optical module to move in small amplitude on the Z axis. When the XY moving platform carries the wafer to be tested and moves along the positive direction of the X axis or the reverse direction of the X axis, the moving distance of the common optical path optical module on the Z axis is relatively small, which is suitable for using the piezoelectric displacement stage to control the movement of the common optical path optical module on the Z axis. When the XY moving platform carries the wafer to be tested and moves along the positive direction of the Y axis, the moving distance of the common optical path optical module on the Z axis is relatively large, which is suitable for using the stepper motor to control the movement of the common optical path optical module on the Z axis.
[0057] In this way, when the XY moving platform moves along the X axis, the height difference of the wafer to be tested is small, and the piezoelectric displacement platform controls the moving position of the common optical path optical module, so that the common optical path optical module can capture a clear image. When the XY moving platform moves along the Y axis, the height difference of the wafer to be tested may be large, and the stepper motor controls the moving position of the common optical path optical module so that the common optical path optical module can quickly reach a position where a clear image can be captured.
[0058] Specifically, the common optical path optical module is installed on the piezoelectric displacement stage through a connector, and the piezoelectric displacement stage is connected to a high-precision displacement control stepper motor through a connector. The high-precision displacement control stepper motor is installed on the marble gantry through a connector.
[0059] Preferably, see again Figure 3 and Figure 4 , a wafer defect detection system also includes an adsorption machine 11. Wherein, the adsorption mechanism 11 is installed on the XY moving platform 4. The XY moving platform is used to place the wafer to be tested through the adsorption mechanism.
[0060] The wafer to be tested is fixed on the XY moving platform by the adsorption mechanism, so that when the XY moving platform moves, the wafer to be tested can remain relatively still with the XY moving platform, so that the XY moving platform can control the moving position of the wafer to be tested.
[0061] Preferably, a wafer defect detection system further includes a display module; the display module is connected to the industrial computer for communication. The industrial computer is also used to determine the defect status of the wafer to be tested based on the image transmitted by the common optical path optical module, and transmit the defect status to the display module. The display module is used to display the defect status of the wafer to be tested.
[0062] In this way, the defect condition of the wafer to be tested is determined by the industrial computer and transmitted to the display module, which triggers the display module to display the defect condition of the wafer to be tested, so that the technicians can find the detection condition of the wafer to be tested in time.
[0063] In some embodiments, the display module is a display.
[0064] For further information, see Figure 3 and Figure 4 , a wafer defect detection system also includes a signal controller 9. The industrial computer 10 is connected to the signal controller 9 through a communication cable. The signal controller 9 is connected to the ATF unit 5, the piezoelectric displacement stage 8 and the stepper motor 7. The industrial computer controls the ATF unit, the piezoelectric displacement stage and the stepper motor through the signal controller. For ease of understanding, this figure only shows the communication connection relationship between the signal controller and the ATF unit.
[0065] Specifically, the industrial computer sends a focus instruction to the ATF unit through the signal controller, triggering the ATF unit to automatically focus. The ATF unit sends the focus instruction information of the automatic focus direction to the industrial computer through the signal controller, and the industrial computer determines the height value based on the focus instruction information.
[0066] A computing device according to an embodiment of the present invention includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, some or all steps of the above-mentioned wafer defect detection path planning method are implemented.
[0067] Among them, the computing device can be a computer, and correspondingly, its program is computer software. The above-mentioned parameters and steps in a computing device of the present invention can refer to the parameters and steps in an embodiment of a wafer defect detection path planning method above, and will not be repeated here.
[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0069] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.
Claims
1. A wafer defect detection path planning method, characterized in that: include: The wafer to be tested is moved by an XY moving platform until the height values at at least four preset sampling points on the edge of the wafer to be tested are collected by the common optical path optical module; wherein the XY moving platform is used to place the wafer to be tested, and each preset sampling point is evenly distributed on the edge of the wafer to be tested; Arrange each height value in order and obtain the top two preset sampling points; Obtaining a line connecting the two preset sampling points, and drawing a perpendicular bisector of the line, and obtaining two intersection points where the perpendicular bisector of the line intersects with the edge of the wafer to be measured; The line between the two preset sampling points is used as the X-axis, the line between the two intersection points is used as the Y-axis, and one of the intersection points is used as the starting point and the other intersection point is used as the final point; The common light path optical module is controlled to start shooting from the starting point, and the detection path of the XY mobile platform is planned through the X-axis and the Y-axis until the common light path optical module shoots an image of the final point.
2. The method according to claim 1, characterized in that The height values at at least four preset sampling points on the edge of the wafer to be tested are collected by the common optical path optical module, including: Focusing each preset sampling point through the common optical path optical module to obtain focus instruction information; wherein the focus instruction information represents the distance information that needs to be adjusted when the ATF unit of the common optical path optical module instructs the area array camera of the common optical path optical module to clearly image the photographed object; Obtaining the focal length of the objective lens of the common light path optical module; Determine the distance value between each of the preset sampling points and the objective lens based on the focus instruction information corresponding to each of the preset sampling points and the focal length of the objective lens; The height value at each of the preset sampling points is determined based on each of the distance values.
3. The method according to claim 2, characterized in that The step of determining the height value at each of the preset sampling points based on each of the distance values comprises: Acquire the height value of the objective lens when the common optical path optical module focuses on each preset sampling point; The height value of the objective lens is subtracted from each distance value to determine the height value at each preset sampling point.
4. The method according to any one of claims 1 to 3, characterized in that: The controlling the common light path optical module to start shooting from the starting point, and planning the detection path of the XY mobile platform through the X-axis and the Y-axis until the common light path optical module shoots an image of the final point, includes: Controlling the common light path optical module to start shooting from the starting point, and controlling the XY moving platform to move periodically along a preset path until controlling the common light path optical module to shoot an image of the final point; The preset path includes: Controlling the XY moving platform to move along the positive direction of the X axis until the common optical path optical module captures an image of the edge of the wafer to be tested; After controlling the XY moving platform to move a preset distance along the positive direction of the Y axis, it moves along the reverse direction of the X axis until the common optical path optical module captures an image of the edge of the wafer to be measured; wherein the positive direction of the Y axis is the direction from the starting point to the end point; Control the XY mobile platform to move a preset distance along the positive direction of the Y axis.
5. A wafer defect detection system, characterized in that: include: Gantry, Z-axis moving table, common light path optical module, XY moving platform and industrial computer; wherein the Z-axis moving table is installed on the gantry, the common light path optical module is installed on the Z-axis moving table; the XY moving platform is arranged below the common light path optical module; the Z-axis moving table, the common light path optical module and the XY moving platform are all connected to the industrial computer for communication; The common optical path optical module is used to collect images of each test point of the wafer to be tested, and transmit each image to the industrial computer; The Z-axis moving stage is used to move the position of the common light path optical module along the Z-axis direction based on the real-time focusing condition of the common light path optical module; The XY moving platform is used to place the wafer to be tested; The industrial computer is used to implement a wafer defect detection path planning method as described in claim 1, and control the operation of the XY mobile platform based on the planned detection path.
6. The system according to claim 5, characterized in that The common optical path optical module includes an ATF unit and an area array camera; wherein the ATF unit and the area array camera are both communicatively connected to the industrial computer; The area array camera is used to automatically focus on each sampling point through the ATF unit, obtain the focused image, and transmit the image to the industrial computer.
7. The system according to claim 5, characterized in that The Z-axis moving stage includes a stepper motor and a piezoelectric displacement stage; wherein the stepper motor is installed on the gantry, the piezoelectric displacement stage is installed on the stepper motor, and the common optical path optical module is installed on the piezoelectric displacement stage; the stepper motor and the piezoelectric displacement stage are both connected to the industrial computer for communication; The industrial computer is further used to control the stepping motor to move along the Z-axis direction before the common optical path optical module detects the starting point, until the moving range of the piezoelectric displacement stage meets the focusing requirement of the optical path optical module on the starting point; And, when the XY moving platform is controlled to move along the positive direction of the X-axis or the reverse direction of the X-axis, the piezoelectric displacement stage is controlled to move along the Z-axis direction based on the real-time focusing condition of the common optical path optical module; And, when the XY moving platform is controlled to move along the positive direction of the Y axis, the stepping motor is controlled to move along the Z axis until the moving range of the piezoelectric displacement stage meets the focusing requirement of the common optical path optical module on the current point to be measured.
8. The system according to claim 5, characterized in that It also includes an adsorption mechanism; wherein the adsorption mechanism is installed on the XY moving platform; The XY moving platform is used to place the wafer to be tested through the adsorption mechanism.
9. The system according to any one of claims 5 to 8, characterized in that: It also includes a display module; the display module is communicatively connected with the industrial computer; The industrial computer is further used to determine the defect status of the wafer to be tested based on the image transmitted by the common optical path optical module, and transmit the defect status to the display module; The display module is used to display the defect status of the wafer to be tested.
10. A computing device comprising a memory, a processor, and a program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of a wafer defect detection path planning method as described in any one of claims 1 to 4 are implemented.