Wafer defect detection method and device

Abstract

The invention provides a wafer defect detection method and device, and relates to the technical field of semiconductors, and the wafer defect detection method comprises the steps: carrying out the laser scanning of a wafer, and obtaining the first position information and the first size information of a defect on the wafer; performing optical scanning on the wafer by using an optical microscope and performing electronic scanning on the wafer by using a scanning electron microscope according to the first position information and the first size information to obtain second position information and second size information of the defect on the wafer; and taking the second position information and the second size information as positioning detection information of defects on the wafer. According to the embodiment of the invention, a combined scanning mode of laser scanning, optical scanning and electronic scanning is used for carrying out positioning detection on the wafer defects, so that missing detection and false detection of the defects are avoided, and the accuracy of wafer defect detection is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a method and device for detecting wafer defects. Background Art

[0002] In the manufacturing process of semiconductor wafers, defect detection and defect classification of wafers are key steps in wafer quality control. In the prior art, for defect detection of wafers, it is generally carried out by combining an optical microscope (OM) and a scanning electron microscope (SEM), that is, wafer defects are identified jointly through the optical mode (OM mode) and the scanning electron microscope mode (SEM mode).

[0003] However, in the above identification method, since the defect position signal of the wafer is weak in the OM mode (especially for small-sized defects), when switching from the OM mode to the SEM mode, the defects with weak signal positions may be marked as non-defect points, that is, the problem of missed detection occurs, wasting detection resources and inaccurately detecting wafer defects. Summary of the Invention

[0004] Embodiments of the present invention provide a method and device for detecting wafer defects to solve the problem of possible missed detection when detecting wafer defects in the prior art.

[0005] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] Embodiments of the present invention provide a method for detecting wafer defects, the method comprising:

[0007] Performing laser scanning on a wafer to obtain first position information and first size information of defects on the wafer;

[0008] According to the first position information and the first size information, performing optical scanning on the wafer using an optical microscope and performing electron scanning on the wafer using a scanning electron microscope to obtain second position information and second size information of defects on the wafer;

[0009] Taking the second position information and the second size information as positioning detection information of defects on the wafer.

[0010] In some embodiments, performing laser scanning on a wafer to obtain first position information and first size information of defects on the wafer includes:

[0011] Scanning the surface of the wafer with a laser beam to obtain the reflection intensity of the laser beam at different positions on the surface of the wafer;

[0012] Based on the reflection intensity, the first position information and the first size information of the defect on the wafer are obtained.

[0013] In some embodiments, a laser beam is used to scan the surface of the wafer to obtain the reflection intensities of the laser beam at different positions on the surface of the wafer, including:

[0014] Controlling the rotation of the wafer;

[0015] During the rotation of the wafer, controlling the laser beam to move from the center of the surface of the wafer along the radial direction to the edge of the surface of the wafer to obtain the reflection intensities of the laser beam at different positions on the surface of the wafer.

[0016] In some embodiments, according to the first position information and the first size information, the wafer is optically scanned using an optical microscope and electronically scanned using a scanning electron microscope to obtain the second position information and the second size information of the defect on the wafer, including:

[0017] For the defect indicated by the first position information and the first size information, the first area where the defect is located is optically scanned using the optical microscope to obtain the optical signal intensity corresponding to the defect;

[0018] Based on the optical signal intensity, the second area where the defect on the wafer is located is electronically scanned using the scanning electron microscope to obtain the second position information and the second size information of the defect on the wafer.

[0019] In some embodiments, based on the optical signal intensity, the second area where the defect on the wafer is located is electronically scanned using the scanning electron microscope to obtain the second position information and the second size information of the defect on the wafer, including:

[0020] When the optical signal intensity is greater than a preset intensity threshold, based on the optical signal intensity, the third position information and the third size information corresponding to the defect are obtained;

[0021] For the defect indicated by the third position information and the third size information, the second area where the defect is located is electronically scanned using the scanning electron microscope to obtain the second position information and the second size information of the defect.

[0022] In some embodiments, based on the optical signal intensity, the second area where the defect on the wafer is located is electronically scanned using the scanning electron microscope to obtain the second position information and the second size information of the defect on the wafer, including:

[0023] When the optical signal intensity is greater than a preset intensity threshold, third position information and third dimension information corresponding to the defect are obtained according to the optical signal intensity;

[0024] For the defect indicated by the third position information and the third dimension information, the second region where the defect is located is scanned electronically by using the scanning electron microscope to obtain the second position information and the second dimension information of the defect.

[0025] In some embodiments, according to the optical signal intensity, the second region where the defect of the wafer is located is scanned electronically by using the scanning electron microscope to obtain the second position information and the second dimension information of the defect on the wafer, including:

[0026] When the optical signal intensity is less than or equal to the preset intensity threshold, for the defect indicated by the first position information and the first dimension information, the second region where the defect is located is scanned electronically by using the scanning electron microscope to obtain the second position information and the second dimension information of the defect;

[0027] Wherein, the optical signal intensity is less than the intensity of the electronic scanning signal of the scanning electron microscope.

[0028] In some embodiments, before the second region where the defect of the wafer is located is scanned electronically by using the scanning electron microscope according to the optical signal intensity to obtain the second position information and the second dimension information of the defect on the wafer, the method further includes:

[0029] Performing coordinate calibration on the optical microscope and the scanning electron microscope.

[0030] In some embodiments, the method further includes:

[0031] For the defect indicated by the second position information and the second dimension information, the morphological feature information of the defect is obtained by using the scanning electron microscope;

[0032] Defect type information of the defect is obtained according to the morphological feature information.

[0033] In some embodiments, obtaining the defect type information of the defect according to the morphological feature information includes:

[0034] Inputting the morphological feature information into a trained defect type detection model to obtain the defect type information output by the defect type detection model;

[0035] Among them, the defect type detection model is trained by using a preset neural network model, historical morphological feature information of the defects on the wafer, and historical defect type information of the defects on the wafer.

[0036] An embodiment of the present invention also provides a wafer defect detection device, and the device includes:

[0037] A first processing module, configured to perform laser scanning on the wafer to obtain first position information and first size information of the defects on the wafer;

[0038] A second processing module, configured to perform optical scanning on the wafer by using an optical microscope and perform electron scanning on the wafer by using a scanning electron microscope according to the first position information and the first size information, so as to obtain second position information and second size information of the defects on the wafer;

[0039] A third processing module, configured to use the second position information and the second size information as position detection information of the defects on the wafer.

[0040] The embodiment of the present invention has the following beneficial effects:

[0041] For the wafer defect detection method provided by the embodiment of the present invention, first, laser scanning is performed on the wafer to obtain first position information and first size information of the defects on the wafer surface, that is, preliminary scanning is performed on the wafer to obtain preliminary positioning information of the defects on the wafer surface. After that, taking the first position information and the first size information as a reference, optical scanning is performed on the wafer by using an optical microscope and electron scanning is performed on the wafer by using a scanning electron microscope to obtain positioning detection information of the defects on the wafer, and the final precise positioning of the defects on the wafer surface is completed. The embodiment of the present invention uses a combined scanning method of laser scanning, optical scanning, and electron scanning to perform positioning detection on wafer defects, avoiding missed detection and misdetection of defects, and improving the accuracy of defect detection on the wafer. Description of the Drawings

[0042] Figure 1 A schematic diagram showing the wafer defect detection and recognition result provided by the embodiment of the present invention;

[0043] Figure 2 A schematic diagram showing the positioning of the defects provided by the embodiment of the present invention;

[0044] Figure 3 A schematic diagram showing one of the SEM mode detections provided by the embodiment of the present invention;

[0045] Figure 4 A flowchart showing the wafer defect detection method provided by the embodiment of the present invention;

[0046] Figure 5Schematic diagram II for SEM mode detection provided by an embodiment of the present invention;

[0047] Figure 6 Schematic structural diagram of a wafer defect detection device provided by an embodiment of the present invention. Detailed implementation manners

[0048] To make the technical problems, technical solutions and advantages to be solved by the embodiments of the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0049] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention fall within the scope of protection of the present invention.

[0050] Before describing the specific implementation manners of the present invention, the following explanations are made first:

[0051] After performing OM defect detection on a wafer through an optical microscope, the wafer defect detection and recognition result as shown in Figure 1 is obtained. The red substances shown in Figure 1 represent the defects on the wafer. All the defects on the wafer are located within the range of ±3um. The schematic diagram for locating one of the defects is as shown in Figure 2 . However, since in the OM mode, the defect position signal of the wafer is weak, when converting from the OM mode to the SEM mode, the defects with weak signal positions may be marked as non-defect points, resulting in the inability to scan out defects in the SEM mode. Exemplarily, as shown in Figure 3 Figure 3 The upper part of Figure 3 correctly marks the defect points. For the correctly marked defect points, SEM mode detection can clearly detect the defects on the wafer (i.e., the linear defects shown in Figure 3 ), that is, the detection part corresponding to the green arrow.

[0052] The lower part of

[0053] shows the defect points that are not correctly marked (i.e., non-defect points are marked). For the defect points that are not correctly marked, SEM mode detection cannot detect the defects on the wafer, that is, the detection part corresponding to the red arrow. Figure 4As shown in the figure, an embodiment of the present invention provides a wafer defect detection method, and the method includes:

[0054] Step 401: Laser scan the wafer to obtain the first position information and the first size information of the defects on the wafer.

[0055] In this step, a laser beam is used to scan the surface of the wafer to preliminarily locate the defects on the wafer surface, and the first position information and the first size information of the defects on the wafer surface are obtained. The first position information and the first size information are used as the preliminary location detection information of the defects on the wafer, and the preliminary location detection information is output as a Klarf file for recording.

[0056] It can also be understood that the first position information and the first size information are used to indicate the preliminarily located defect area on the wafer.

[0057] Exemplarily, the defects on the wafer may include multiple types, and each type of defect may also have different sizes. Exemplarily, different types of wafer defects include particle defects, scratch defects, or include crystal native defects, continuity defects. Different types of defects may have different sizes. The sizes of some small-sized defects may be only a few micrometers, and the sizes of some large-sized defects may be as high as dozens of micrometers or even hundreds of micrometers. These different types and different-sized defects will be preliminarily located and detected to obtain the first position information and the first size information of the defects, and output as a Klarf file for recording.

[0058] Before obtaining the first position information and the first size information, a coordinate system can be established on the wafer surface. The coordinate center of this coordinate system is the center of the surface of the wafer after wire cutting. Connect the center of the wafer surface with the wafer notch (Notch), establish a longitudinal coordinate axis on the straight line where this connection is located, and establish a transverse coordinate axis on the straight line perpendicular to the straight line where this connection is located.

[0059] Among them, the first position information includes the position coordinates of the defects on the wafer, and the position coordinates where the defects are located can be the center position coordinates of the defects.

[0060] The first size information includes the position coordinates of the edges of the defects on the wafer, that is, since the position coordinates of the edges of the defects can reflect the shape and size of the defects.

[0061] According to the position coordinates of the edges of the defect, the central position coordinates of the defect can be calculated. Specifically, according to the position coordinates of the edges of the defect, the first position coordinates of the two farthest edge points on the defect in the radial direction are obtained, and the second position coordinates of the two farthest edge points on the defect in the circumferential direction are obtained. Connect the two first position coordinates and connect the two second position coordinates. The intersection coordinates of the two connections are the central position coordinates of the defect.

[0062] Step 402: According to the first position information and the first dimension information, use an optical microscope to perform an optical scan on the wafer and use a scanning electron microscope to perform an electron scan on the wafer to obtain the second position information and the second dimension information of the defects on the wafer.

[0063] In this step, after obtaining the preliminary positioning detection information of the defects indicated by the above first position information and first dimension information, in order to achieve accurate identification and detection of the defects, based on the above first position information and first dimension information, use an optical microscope to perform an optical scan on the wafer and use a scanning electron microscope to perform an electron scan on the wafer, that is, perform a precise scan on the wafer using the OM mode and the SEM mode to obtain the second position information and the second dimension information of the defects.

[0064] It should be noted that the parameters and meanings included in the second position information are basically the same as those included in the above first position information, but their specific values may be different. The parameters and meanings included in the second dimension information are basically the same as those included in the above first dimension information, but their specific values may be different.

[0065] Step 403: Use the second position information and the second dimension information as the positioning detection information of the defects on the wafer.

[0066] Use the above second position information and second dimension information as the positioning detection information of the defects on the wafer, and this positioning detection information is used as the final positioning detection information of the defects.

[0067] In the embodiment of the present invention, a combined scanning method of laser scanning, optical scanning, and electron scanning is used to perform positioning detection on wafer defects, avoiding missed detection and misdetection of defects, especially missed detection and misdetection of small-size defects, improving the accuracy of defect detection on wafers, and enhancing the recognition ability of small-size defects on the wafer surface.

[0068] Exemplarily, for the native crystal defects of only a few micrometers, when using the existing OM mode plus SEM mode for detection, in the OM mode, the signal at the position of the native crystal defects of only a few micrometers is relatively weak, resulting in this position may be marked as a non-defect point. After switching from the OM mode to the SEM mode, missed detections will occur. However, through the above steps provided by the embodiments of the present invention, for the native crystal defects of only a few micrometers, using a combined scanning method of laser scanning, optical scanning, and electron scanning, in the laser scanning mode, the first position information and the first size information of the native crystal defects of only a few micrometers can be obtained. In the OM mode, even if the signal at the position of the native crystal defects of only a few micrometers is relatively weak, after switching from the OM mode to the SEM mode, SEM detection can also be performed according to the first position information and the first size information to avoid missed detections.

[0069] In some embodiments, laser scanning is performed on the wafer to obtain the first position information and the first size information of the defects on the wafer, including:

[0070] The wafer surface is scanned with a laser beam to obtain the reflection intensities of the laser beam at different positions on the wafer surface. Specifically, a high-precision detection device, a particle counter, is used to emit a laser beam onto the wafer surface, and the reflection intensities of the laser beam at the normal positions and defect positions on the wafer surface are collected;

[0071] Based on the reflection intensities, the first position information and the first size information of the defects on the wafer are obtained. Since the intensities of the laser beam reflected at the normal positions and defect positions on the wafer surface without defects are different, therefore, based on the reflection intensities, the edge positions of the defects on the wafer can be calculated. Based on the edge positions, the first position information and the first size information of the defects are calculated, and the first position information and the first size information of the defects are output as a Klarf file, recording the position coordinates and size characteristics of all defects.

[0072] Exemplarily, for the continuous defects on the wafer, based on the reflection intensity of the laser beam on the continuous defects on the wafer surface, the outer contour of the continuous defects can be determined. Based on the outer contour, the shape and size of the continuous defects can be obtained, and the center position of the contour can also be determined as the position of the defects.

[0073] Optionally, scanning the wafer surface with a laser beam to obtain the reflection intensities of the laser beam at different positions on the wafer surface includes:

[0074] Controlling the rotation of the wafer, the wafer can be placed on a wafer carrier, and the wafer is rotated by driving the rotation of the wafer carrier.

[0075] During the rotation of the wafer, control the laser beam to move from the center of the wafer surface along the radial direction to the edge of the wafer surface, and obtain the reflection intensities of the laser beam at different positions on the wafer surface.

[0076] That is, by controlling the wafer to perform high-precision and repeatable rotational motion, and controlling the laser beam to perform high-precision linear motion, scan to obtain the reflection intensities at different positions on the wafer surface, where the different positions on the wafer surface can be indicated in the form of coordinates.

[0077] It should be noted that when controlling the laser beam to move from the center of the wafer surface after wire cutting along the radial direction to the edge of the wafer surface after wire cutting, after the wafer rotates one or several circles, control the laser beam to move a small distance, and then control the wafer to rotate one or several circles to ensure a comprehensive scan of the wafer surface by the laser beam.

[0078] In some embodiments, according to the first position information and the first dimension information, use an optical microscope to perform optical scanning on the wafer and use a scanning electron microscope to perform electron scanning on the wafer, and obtain the second position information and the second dimension information of the defects on the wafer, including:

[0079] For the defects indicated by the first position information and the first dimension information, use the optical microscope to perform optical scanning on the first region where the defects are located, and obtain the optical signal intensity corresponding to the defects.

[0080] Among them, the first region where the defects are located is determined according to the first position information and the first dimension information. It can be understood that the first region takes the central position coordinates of the defects indicated by the first position information as the midpoint, and a circular or rectangular region is divided around the midpoint, and this circular or rectangular region is a region that can include the edge positions of the defects indicated by the first dimension information.

[0081] Optionally, according to historical experience, a rectangular region of 100um * 100um can be divided around the midpoint as the region where the defects are located.

[0082] Switch the optical lens of the optical microscope to the position facing the central position coordinates of the defects, and perform scanning within a field of view of 100um * 100um to obtain the optical signal intensity corresponding to the defects.

[0083] According to the optical signal intensity, use the scanning electron microscope to perform electron scanning on the second region where the defects of the wafer are located, and obtain the second position information and the second dimension information of the defects on the wafer.

[0084] After obtaining the above-mentioned optical signal intensity, the area where the defect is located can be re-divided according to the optical signal intensity to obtain the second area where the defect of the wafer is located. It should be noted that the first area and the second area may be the same or different. Using a scanning electron microscope (SEM) to accurately scan the defects in the second area can make the second position information and the second size information of the obtained defects more accurate.

[0085] Exemplarily, for continuous defects, if the first position information and the first size information of the continuous defects are obtained by laser scanning, and if the detection effect of the edge position of the continuous defect by the laser beam is poor, the area of the continuous defect determined by the first position information and the first size information may be inaccurate. Therefore, using a scanning electron microscope to perform an electron scan on the area where the defect of the wafer is located, re-dividing the area where the defect is located, and obtaining more accurate second position information and second size information of the continuous defect.

[0086] In an optional implementation manner, according to the optical signal intensity, using the scanning electron microscope to perform an electron scan on the second area where the defect of the wafer is located to obtain the second position information and the second size information of the defect on the wafer, including:

[0087] When the optical signal intensity is greater than a preset intensity threshold, according to the optical signal intensity, the third position information and the third size information corresponding to the defect are obtained.

[0088] The optical signal intensity detected in the optical mode is greater than the optical signal intensity corresponding to the normal position without defects on the wafer. Therefore, when the optical signal intensity is greater than the preset intensity threshold, according to the optical signal intensity, the third position information and the third size information of the defect position detected in the optical mode can be obtained. It can be understood that the third position information and the third size information are used to indicate the defect area located in the optical mode.

[0089] For the defects indicated by the third position information and the third size information, using the scanning electron microscope to perform an electron scan on the second area where the defect is located to obtain the second position information and the second size information of the defect.

[0090] It should be noted that the parameters and meanings included in the third position information and the above-mentioned first position information are basically the same, but their specific values may be different. The parameters and meanings included in the third size information and the above-mentioned first size information are basically the same, but their specific values may be different.

[0091] That is, according to the third position information and the third dimension information, determine the second area where the defect is located. Using the central position coordinates of the defect indicated by the third position information as the midpoint, divide a circular or rectangular area around the midpoint. This circular or rectangular area is an area that can include the edge positions of the defect indicated by the third dimension information.

[0092] Exemplarily, for native defects or continuous defects of dozens of micrometers on a wafer, if the optical signal intensity of the defects detected according to the above process is greater than a preset intensity threshold, then according to the optical signal intensity, obtain the defect area in this optical mode.

[0093] In an alternative embodiment, according to the optical signal intensity, use the scanning electron microscope to perform an electron scan on the second area where the defect of the wafer is located, and obtain the second position information and the second dimension information of the defect on the wafer, including:

[0094] In the case where the optical signal intensity is less than or equal to the preset intensity threshold, for the defect indicated by the first position information and the first dimension information, use the scanning electron microscope to perform an electron scan on the second area where the defect is located, and obtain the second position information and the second dimension information of the defect;

[0095] Wherein, the optical signal intensity is less than the intensity of the electron scan signal of the scanning electron microscope.

[0096] If the optical signal intensity is less than or equal to the intensity threshold, it means that in the optical mode, the signal corresponding to the defect is weak, especially when the defect is a small-sized defect. At this time, in order to avoid missed detection or misdetection, directly use the above first position information and first dimension information to determine the area where the defect is located. That is, in this alternative embodiment, the second area where the defect is located is the above-mentioned first area where the defect is located. For this first area, also use SEM for precise scanning. The intensity of the electron scan signal of this SEM is greater than the optical signal intensity, which can avoid misjudgment caused by mislabeling or missed labeling in the OM mode.

[0097] That is, in this alternative embodiment, when the signal is weak in the OM mode, directly read the defect coordinates in the Klarf file for SEM scanning to ensure the accuracy of the SEM scanning and avoid obtaining invalid detection results (Nothing) in the scanning.

[0098] Exemplarily, for some small-sized defects of several micrometers, laser scanning obtains the first position information and the first size information of the defect. In the OM mode, according to the first position information and the first size information, if the optical signal intensity for detecting the small-sized defect of several micrometers is less than or equal to the intensity threshold, it proves that in the optical mode, the signal corresponding to the small-sized defect is weak. At this time, to avoid missed detection, the first position information and the first size information are called, and the SEM is used to precisely scan the small-sized defect of several micrometers. Moreover, the intensity of the electron scanning signal of the SEM is greater than the optical signal intensity, avoiding misjudgment caused by missed marking in the OM mode.

[0099] It should also be noted that before obtaining the second position information and the second size information of the defect on the wafer by performing electron scanning on the second area where the defect of the wafer is located using the scanning electron microscope according to the optical signal intensity, the method further includes:

[0100] Performing coordinate calibration on the optical microscope and the scanning electron microscope.

[0101] Specifically, the Deskew technology is used to calibrate the parallel angle and the planar coordinates of the wafer to ensure the consistency of the coordinate system in subsequent detections.

[0102] In some embodiments, the method further includes:

[0103] For the defect indicated by the second position information and the second size information, using the scanning electron microscope to obtain the morphological feature information of the defect.

[0104] Specifically, after positioning the defect according to the second position information and the second size information, the scanning electron microscope is used to perform high-resolution scanning on the second area where the defect is located, and the morphological feature information of the defect is output.

[0105] According to the morphological feature information, the defect type information of the defect is obtained. That is, according to the morphological feature information, the defect is classified to obtain the type of the defect.

[0106] For example, according to the morphological feature information, the particle defects and scratch defects on the wafer can be divided to obtain which part of the wafer is particle defects and which part is scratch defects.

[0107] It should also be noted that after obtaining the type and location information of the defect, the above information can also be fed back to the production line in real time. By integrating historical defect data and real-time production data, it provides support for the optimization of the production process, improves the accuracy and consistency of defect management, and ensures the efficiency and stability of the detection process.

[0108] Among them, obtaining the defect type information of the defect according to the morphological feature information includes:

[0109] Inputting the morphological feature information into a trained defect type detection model to obtain the defect type information output by the defect type detection model;

[0110] Among them, the defect type detection model is trained by using a preset neural network model, historical morphological feature information of defects on the wafer, and historical defect type information of defects on the wafer.

[0111] Among them, the neural network model includes at least one of the following:

[0112] Convolutional Neural Networks (CNN);

[0113] Long Short-Term Memory (LSTM);

[0114] Bi-directional long-short term memory (Bi-LSTM).

[0115] That is, it is trained by using a large amount of known historical morphological feature information and historical defect type information to obtain a trained defect type detection model. Input the morphological feature information into the trained defect type detection model, and the defect type detection model automatically classifies the defects in the morphological feature information and outputs the defect type information.

[0116] The following specifically illustrates the effect of the wafer defect detection method provided by the embodiments of the present invention:

[0117] Taking the laser scanning of the wafer to obtain the wafer defect detection and recognition result as shown in Figure 1 as an example, for the first defect position information and the first size information shown in Figure 1 , use the optical microscope to perform optical scanning on the first area where the defect is located to obtain the optical signal intensity corresponding to the defect. When the optical signal intensity is greater than a preset intensity threshold, according to the optical signal intensity, obtain the third position information and the third size information corresponding to the defect. For the defect indicated by the third position information and the third size information, use the scanning electron microscope to perform electron scanning on the second area where the defect is located. As shown in the upper part of Figure 5 , if the optical signal intensity of the located defect is greater than the preset intensity threshold, then perform SEM scanning on this defect to obtain the specific position and size of the defect. The SEM detection process is as shown in Figure 5As shown by the green arrow in the upper part. When the optical signal intensity is less than or equal to a preset intensity threshold, for the defect indicated by the first position information and the first size information, the scanning electron microscope is used to precisely scan the second area where the defect is located, and the optical signal intensity is less than the intensity of the electron scanning signal of the scanning electron microscope, as Figure 5 As shown in the lower part, if the optical signal intensity of the defect indicated by the first position information and the first size information is less than or equal to the preset intensity threshold, then SEM scanning is performed on this defect to obtain the specific position and size of this defect. The SEM detection process is as Figure 5 shown by the red arrow in the lower part.

[0118] As Figure 6 shown, an embodiment of the present invention further provides a wafer defect detection device, and the device includes:

[0119] A first processing module 601, configured to perform laser scanning on a wafer to obtain first position information and first size information of defects on the wafer;

[0120] A second processing module 602, configured to perform optical scanning on the wafer using an optical microscope and perform electron scanning on the wafer using a scanning electron microscope according to the first position information and the first size information, to obtain second position information and second size information of defects on the wafer;

[0121] A third processing module 603, configured to use the second position information and the second size information as position detection information of defects on the wafer.

[0122] Optionally, the first processing module 601 includes:

[0123] A first processing unit, configured to scan the surface of the wafer with a laser beam to obtain the reflection intensity of the laser beam at different positions on the surface of the wafer;

[0124] A second processing unit, configured to obtain the first position information and the first size information of the defects on the wafer according to the reflection intensity.

[0125] Optionally, the first processing unit is specifically configured to:

[0126] Control the rotation of the wafer;

[0127] During the rotation of the wafer, control the laser beam to move from the center of the surface of the wafer along the radial direction to the edge of the surface of the wafer to obtain the reflection intensity of the laser beam at different positions on the surface of the wafer.

[0128] Optionally, the second processing module 602 includes:

[0129] A third processing unit, configured to perform an optical scan on a first area where the defect is located by using the optical microscope for the defect indicated by the first position information and the first size information, so as to obtain an optical signal intensity corresponding to the defect;

[0130] A fourth processing unit, configured to perform an electron scan on a second area where the defect of the wafer is located by using the scanning electron microscope according to the optical signal intensity, so as to obtain the second position information and the second size information of the defect on the wafer.

[0131] Optionally, the fourth processing unit is specifically configured to:

[0132] When the optical signal intensity is greater than a preset intensity threshold, obtain third position information and third size information corresponding to the defect according to the optical signal intensity;

[0133] Perform an electron scan on the second area where the defect is located by using the scanning electron microscope for the defect indicated by the third position information and the third size information, so as to obtain the second position information and the second size information of the defect.

[0134] Optionally, the fourth processing unit is specifically configured to:

[0135] When the optical signal intensity is less than or equal to the preset intensity threshold, perform an electron scan on the second area where the defect is located by using the scanning electron microscope for the defect indicated by the first position information and the first size information, so as to obtain the second position information and the second size information of the defect.

[0136] Optionally, the second processing module 602 further includes:

[0137] A fifth processing unit, configured to perform coordinate correction on the optical microscope and the scanning electron microscope.

[0138] Optionally, the device further includes:

[0139] A fourth processing module, configured to obtain a morphological feature information of the defect by using the scanning electron microscope for the defect indicated by the second position information and the second size information;

[0140] A fifth processing module, configured to obtain a defect type information of the defect according to the morphological feature information.

[0141] Optionally, the fifth processing module includes:

[0142] A fifth processing unit, configured to input the topography feature information into a trained defect type detection model, and obtain the defect type information output by the defect type detection model;

[0143] Wherein, the defect type detection model is trained by using a preset neural network model, historical topography feature information of defects on a wafer, and historical defect type information of defects on the wafer.

[0144] It should be noted that the wafer defect detection device provided in the embodiments of the present invention is a device capable of executing the wafer defect detection method described in any one of the above. All embodiments of the above wafer defect detection method are applicable to this device and can achieve the same or similar technical effects.

[0145] The above is the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A wafer defect detection method, characterized in that, The method includes: Performing laser scanning on the wafer to obtain first position information and first size information of defects on the wafer; According to the first position information and the first size information, performing optical scanning on the wafer using an optical microscope and performing electron scanning on the wafer using a scanning electron microscope to obtain second position information and second size information of defects on the wafer; Taking the second position information and the second size information as the positioning detection information of defects on the wafer.

2. The wafer defect detection method according to claim 1, wherein Performing laser scanning on the wafer to obtain first position information and first size information of defects on the wafer, including: Scanning the surface of the wafer with a laser beam to obtain the reflection intensities of the laser beam at different positions on the surface of the wafer; According to the reflection intensities, obtaining the first position information and the first size information of defects on the wafer.

3. The wafer defect detection method according to claim 2, wherein Scanning the surface of the wafer with a laser beam to obtain the reflection intensities of the laser beam at different positions on the surface of the wafer, including: Controlling the rotation of the wafer; During the rotation of the wafer, controlling the laser beam to move from the center of the surface of the wafer along the radial direction to the edge of the surface of the wafer to obtain the reflection intensities of the laser beam at different positions on the surface of the wafer.

4. The wafer defect detection method according to claim 1, wherein According to the first position information and the first size information, performing optical scanning on the wafer using an optical microscope and performing electron scanning on the wafer using the scanning electron microscope to obtain second position information and second size information of defects on the wafer, including: For the defects indicated by the first position information and the first size information, performing optical scanning on a first region where the defects are located using the optical microscope to obtain the optical signal intensity corresponding to the defects; According to the optical signal intensity, performing electron scanning on a second region where the defects of the wafer are located using the scanning electron microscope to obtain the second position information and the second size information of defects on the wafer.

5. The wafer defect detection method according to claim 4, wherein According to the optical signal intensity, performing electron scanning on a second region where the defects of the wafer are located using the scanning electron microscope to obtain the second position information and the second size information of defects on the wafer, including: In the case where the optical signal intensity is greater than a preset intensity threshold, according to the optical signal intensity, obtaining third position information and third size information corresponding to the defects; For the defects indicated by the third position information and the third size information, performing electron scanning on the second region where the defects are located using the scanning electron microscope to obtain the second position information and the second size information of the defects.

6. The wafer defect detection method according to claim 4, wherein According to the optical signal intensity, performing electron scanning on a second region where the defects of the wafer are located using the scanning electron microscope to obtain the second position information and the second size information of defects on the wafer, including: When the optical signal intensity is less than or equal to a preset intensity threshold, for the defect indicated by the first position information and the first size information, the scanning electron microscope is used to perform an electron scan on the second region where the defect is located, and the second position information and the second size information of the defect are obtained; Wherein, the optical signal intensity is less than the intensity of the electron scan signal of the scanning electron microscope.

7. The wafer defect detection method according to claim 4, wherein Before performing an electron scan on the second region where the defect of the wafer is located by using the scanning electron microscope according to the optical signal intensity to obtain the second position information and the second size information of the defect on the wafer, the method further includes: Performing coordinate calibration on the optical microscope and the scanning electron microscope.

8. The wafer defect detection method according to claim 1, wherein The method further includes: For the defect indicated by the second position information and the second size information, using the scanning electron microscope to obtain the morphological feature information of the defect; Obtaining the defect type information of the defect according to the morphological feature information.

9. The wafer defect detection method according to claim 8, wherein, Obtaining the defect type information of the defect according to the morphological feature information includes: Inputting the morphological feature information into a trained defect type detection model to obtain the defect type information output by the defect type detection model; Wherein, the defect type detection model is trained by using a preset neural network model, historical morphological feature information of the defects of the wafer, and historical defect type information of the defects of the wafer.

10. A wafer defect detection device, characterized in that, The device includes: A first processing module, configured to perform a laser scan on the wafer to obtain the first position information and the first size information of the defects on the wafer; A second processing module, configured to perform an optical scan on the wafer by using an optical microscope and an electron scan on the wafer by using a scanning electron microscope according to the first position information and the first size information, and obtain the second position information and the second size information of the defects on the wafer; A third processing module, configured to use the second position information and the second size information as the position detection information of the defects on the wafer.

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