Wafer detection equipment and wafer detection method

Abstract

The invention provides wafer detection equipment and a wafer detection method, which are used for solving the problem of how to improve the wafer detection efficiency. The wafer detection equipment comprises a double-sided detection unit, the double-sided detection unit comprises a scanning carrying platform, a front optical imaging module and a back optical imaging module, and the scanning carrying platform can linearly move along a first direction; the front optical imaging module and the back optical imaging module are respectively arranged on two opposite sides of the scanning stage and are respectively provided with a back bright field light source and a back dark field light source; when the scanning stage moves along the positive direction of the first direction, the front bright field light source and the back bright field light source are synchronously turned on, and the front optical imaging module and the back optical imaging module respectively generate bright field images of the front and back of the wafer; and when the scanning stage moves along the negative direction of the first direction, the front and back dark field light sources are synchronously turned on, and the front optical imaging module and the back optical imaging module respectively generate dark field images of the front and back of the wafer.

Description

Technical Field

[0001] The present disclosure relates to a wafer inspection device and a wafer inspection method, belonging to the field of chip devices. Background Art

[0002] In the field of wafer inspection technology, traditional inspection devices usually adopt the mode of single-sided inspection followed by wafer flipping to achieve double-sided inspection. This method requires an independent flipping module, resulting in a complex device structure, high space occupancy, and a risk of accidental wafer detachment during flipping. On the other hand, traditional inspection devices only inspect wafers under a single lighting environment, making it difficult to capture multi-dimensional defect information on the wafer surface under different optical conditions; or they need to perform different scanning processes in different lighting environments step by step, resulting in an extended inspection cycle, difficulty in synchronously obtaining multi-dimensional image data of the front and back sides, and low inspection efficiency.

[0003] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] To solve one of the above technical problems, the present disclosure provides a wafer inspection device and a wafer inspection method.

[0005] According to one aspect of the present disclosure, a wafer inspection device is provided. The wafer inspection device includes: a double-sided inspection unit, and the double-sided inspection unit includes: a scanning stage for placing a wafer and linearly moving along a first direction; a front optical imaging module and a back optical imaging module, which are respectively arranged on opposite sides of the scanning stage. The front optical imaging module is provided with a front bright-field light source and a front dark-field light source, and the back optical imaging module is provided with a back bright-field light source and a back dark-field light source. Wherein, when the scanning stage moves in the positive direction of the first direction, the front bright-field light source and the back bright-field light source are synchronously turned on, and the front optical imaging module generates a bright-field image of the front side of the wafer, and the back optical imaging module generates a bright-field image of the back side of the wafer; when the scanning stage moves in the negative direction of the first direction, the front dark-field light source and the back dark-field light source are synchronously turned on, and the front optical imaging module generates a dark-field image of the front side of the wafer, and the back optical imaging module generates a dark-field image of the back side of the wafer.

[0006] According to the technical solution of one aspect of the present disclosure, the wafer inspection device can solve the problem in the traditional technology that the bright-field and dark-field inspections require step-by-step switching of light sources and two independent scans, resulting in low inspection efficiency. This solution automatically switches the bright / dark-field light sources when the scanning stage moves forward / backward, and synchronously obtains the bright-field and dark-field image data of the front and back sides of the wafer during a single round-trip scan, thus solving the problem of low step-by-step inspection efficiency. In wafer surface inspection, the bright-field light source and the dark-field light source are set to capture multi-dimensional defect information on the wafer surface under different optical conditions. The bright-field light source directly irradiates the wafer surface and is suitable for detecting macroscopic foreign objects, scratches, and surface contamination. Its high-brightness characteristic can clearly present the reflectivity difference on the wafer surface; while the dark-field light source, through inclined or lateral illumination, utilizes the scattering effect of surface micro-protrusions or depressions on light to enhance the imaging contrast of microscopic defects such as micro-cracks and shallow residues, which is beneficial to discovering wafer defects and improving the accuracy and efficiency of wafer inspection. At the same time, according to the technical solution of one aspect of the present disclosure, this wafer inspection device does not need to be equipped with an independent flipping module, which can reduce the space occupancy rate of the device and avoid the risk of accidental dropping of the wafer during flipping.

[0007] The wafer inspection device according to at least one embodiment of the present disclosure, wherein the front optical imaging module and the back optical imaging module are respectively arranged above and below the scanning stage; the scanning stage blocks a partial area of the back side of the wafer; the wafer inspection device further includes a rotating and lifting device, which is arranged below the scanning stage. After the scanning stage moves in the positive and negative directions along the first direction, the rotating and lifting device lifts the wafer and rotates it by a first angle, so that a partial area of the back side of the wafer blocked by the scanning stage is exposed; the back optical imaging module generates the bright-field image and the dark-field image of the rotated back side of the wafer, and generates a complete back-side image of the wafer by stitching the images before and after the rotation of the back side of the wafer.

[0008] According to the technical solution of this embodiment, the problem that the back side of the wafer is blocked by the scanning stage is solved. The scanning stage usually needs to fix the wafer by mechanical clamping or vacuum adsorption to achieve stable movement. Since the clamping components of the stage will directly contact the wafer surface, the edge or local area of the wafer is blocked by the stage's own structure during the first scan, making this area unable to be directly imaged by the back-side inspection lens group. By rotating the wafer by a first angle, such as 90° or 180°, and then performing a second scan through the rotating lifting shaft, the originally blocked area can be exposed within the detection field of view. Finally, through image stitching technology, the blind area can be eliminated to achieve complete coverage inspection of the back side of the wafer.

[0009] According to at least one embodiment of the wafer inspection equipment disclosed herein, the rotating lifting device includes a rotating lifting shaft located below the scanning stage, a lifting drive mechanism for lifting the rotating lifting shaft, and a rotating drive mechanism for rotating the rotating lifting shaft to a first angle after the rotating lifting shaft is lifted, and a suction plate for fixing the wafer is provided on the top of the rotating lifting shaft.

[0010] According to the technical solution of this embodiment, a vacuum suction cup, an electrostatic suction cup or other suction cup is installed on the rotary lifting shaft to fix the wafer, so as to keep the wafer stable during the lifting and rotating process. The lifting drive mechanism realizes the lifting action in the vertical direction to ensure that the wafer is separated from the scanning stage after being lifted. The rotating drive mechanism realizes the rotation of the lifting shaft and the wafer.

[0011] According to at least one embodiment of the wafer inspection device disclosed herein, the wafer inspection device also includes a microscopic measurement unit, which includes: a movable stage for carrying a wafer and moving along a horizontal plane; a microscopic measurement lens group, configured to magnify the surface circuit of the wafer carried on the movable stage and generate a microscopic image; a lens group height adjustment mechanism, used to drive the microscopic measurement lens group to move in a vertical direction to achieve focusing; and a data processing module, which is programmed to perform the following operations: establish a wafer surface coordinate map based on the microscopic image generated by the microscopic measurement lens group, and set a target coordinate point of the target circuit to be measured; in a fully automatic mode, control the movable stage to move the wafer to the target coordinate point, and control the lens group height adjustment mechanism to drive the microscopic measurement lens group to move in a vertical direction to achieve focusing; capture all pixel grids of the target circuit in the microscopic image in the measurement direction, and calculate the number of pixel grids N, and calculate the line width W=N×S based on the number of pixel grids N and the pixel grid side length S.

[0012] According to the technical solution of this embodiment, objects on the wafer surface and the width between objects can be automatically detected through the microscopic measurement unit. The data processing module controls the linkage of the mobile stage, the microscopic measurement lens group and the lens group height adjustment mechanism, without the need for manual operation, which can improve the detection efficiency.

[0013] According to the wafer inspection equipment of at least one embodiment of the present disclosure, the data processing module is in manual mode, the movable stage manually adjusts the position of the wafer, and the lens group height adjustment mechanism manually adjusts the height of the micro-measurement lens group to achieve focusing.

[0014] According to the technical solution of this embodiment, the microscopic measurement unit is compatible with fully automatic and manual modes, and can cover the needs of different operating scenarios, such as fully automatic mode for mass production and manual fine-tuning during the debugging period.

[0015] A wafer inspection device according to at least one embodiment of the present disclosure, the wafer inspection device further includes a wafer transfer module and an edge finder. The wafer transfer module includes: a double-arm robot including at least two robotic arms configured to alternately perform wafer pick-up and placement actions; and a moving mechanism for driving the double-arm robot to move linearly in the horizontal direction. Wherein, the double-arm robot is used to take out the wafer from the wafer cassette, transfer the wafer to the edge finder for edge correction, sequentially transfer the wafer to the double-sided inspection unit and the microscopic measurement unit, and after the wafer inspection and measurement are completed, return the wafer to the wafer cassette.

[0016] According to the technical solution of this embodiment, by alternately picking up and placing wafers with double robotic arms, the waiting time is reduced and the transfer efficiency is improved. At the same time, based on the edge correction data, the transfer path is adjusted to solve the positioning error problem caused by wafer position offset.

[0017] A wafer inspection device according to at least one embodiment of the present disclosure, the wafer inspection device further includes a wafer loader, and the wafer loader is provided with the wafer cassette.

[0018] According to another aspect of the present disclosure, there is provided a wafer inspection method implemented by using the above-mentioned wafer inspection device. The wafer inspection method includes the following steps: placing the wafer on the scanning stage; the scanning stage moves in the positive direction of the first direction, the front bright field light source and the back bright field light source are turned on synchronously, the front optical imaging module generates a bright field image of the front side of the wafer, and the back optical imaging module generates a bright field image of the back side of the wafer; when the scanning stage moves in the negative direction of the first direction, the front dark field light source and the back dark field light source are turned on synchronously, the front optical imaging module generates a dark field image of the front side of the wafer, and the back optical imaging module generates a dark field image of the back side of the wafer; comparing the bright field images and dark field images of the front and back sides of the wafer with the standard wafer image template.

[0019] Compared with the prior art, the beneficial effects at least include: through a single round trip of the scanning stage, the collection of double-sided bright field and dark field images is completed synchronously. Compared with the traditional step-by-step inspection that requires 4 single-direction scans, the inspection efficiency is improved, especially suitable for mass production scenarios. The double-sided optical imaging module works synchronously without flipping the wafer, reducing the risk of wafer damage. By combining multi-modal inspections of bright field and dark field, various defects on the front and back sides of the wafer can be identified, and the missed detection rate is reduced.

[0020] The wafer inspection method according to at least one embodiment of the present disclosure further includes the following steps: after the scanning stage moves in the positive and negative directions of the first direction, lift the wafer and rotate it by a first angle to expose a partial area of the back surface of the wafer blocked by the scanning stage; the back surface optical imaging module generates a bright field image and a dark field image of the back surface of the rotated wafer, and generates a complete back surface image of the wafer by stitching the images before and after the rotation of the back surface of the wafer.

[0021] According to the technical solution of this embodiment, by rotating the wafer to expose the area blocked by the scanning stage, the back surface inspection of the wafer is completely covered, ensuring the integrity of the image.

[0022] The wafer inspection method according to at least one embodiment of the present disclosure further includes the following steps: placing the wafer on the moving stage; the data processing module establishes a wafer surface coordinate map based on the microscopic images generated by the microscopic measurement lens group, and sets the target coordinate points of the target circuit lines to be measured; controlling the moving stage to move the wafer to the target coordinate points, and controlling the lens group height adjustment mechanism to drive the microscopic measurement lens group to move in the vertical direction to achieve focusing; capturing all the pixel grids of the target circuit line in the measurement direction in the microscopic image, and calculating the number of pixel grids N, and calculating the line width W = N×S according to the number of pixel grids N and the side length S of the pixel grid.

[0023] According to the technical solution of this embodiment, by establishing a coordinate map through the micro-image feature points and eliminating the influence of optical distortion through the pixel grid calibration algorithm (W = N×S), the measurement accuracy can be improved. The coordinated control of autofocus and stage movement can shorten the measurement time and improve the comprehensive efficiency. Description of the Drawings

[0024] The drawings illustrate exemplary embodiments of the present disclosure and are used in conjunction with the description thereof to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure, and the drawings are included in this specification and form a part of this specification.

[0025] Figure 1 is a perspective view of a wafer inspection device according to an embodiment of the present disclosure.

[0026] Figure 2 is a top view of a wafer inspection device according to an embodiment of the present disclosure.

[0027] Figure 3 is a perspective view of a double-sided inspection unit according to an embodiment of the present disclosure.

[0028] Figure 4 is a perspective view of a double-sided inspection unit after removing the wafer and some components according to an embodiment of the present disclosure.

[0029] Figure 5Schematic diagram of a double-sided detection unit according to an embodiment of the present disclosure.

[0030] Figure 6 Perspective view of a micro measurement unit according to an embodiment of the present disclosure.

[0031] Figure 7 Schematic diagram of a wafer coordinate system according to an embodiment of the present disclosure.

[0032] Figure 8 Schematic diagram of line width calculation according to an embodiment of the present disclosure.

[0033] Figure 9 Perspective view of a wafer transfer module according to an embodiment of the present disclosure; Figure 10 Perspective view of a wafer loader according to an embodiment of the present disclosure; Figure 11 Exploded view of a wafer loader according to an embodiment of the present disclosure; Figure 12 Top view of a wafer loader according to an embodiment of the present disclosure; Figure 13 is Figure 12 Perspective sectional view of cross-section A in Figure 14 Perspective view of a baffle module with some components removed according to an embodiment of the present disclosure; Figure 15 Partial perspective view of a baffle module according to an embodiment of the present disclosure; Figure 16 Perspective view of a baffle connected in sequence through a slideway and a second slider according to an embodiment of the present disclosure; Figure 17 Exploded view of a stage module and a wafer cassette according to an embodiment of the present disclosure; Figure 18 Perspective view of the internal structure of a stage module according to an embodiment of the present disclosure; Figure 19 Exploded view of an open cover detection module according to an embodiment of the present disclosure; Figure 20 Perspective view of the internal structure of an open cover component according to an embodiment of the present disclosure; Figure 21 Perspective view of a detection component according to an embodiment of the present disclosure; Figure 22 Perspective view of a track groove according to an embodiment of the present disclosure. Detailed implementation manners

[0034] The present disclosure will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant content and do not limit the present disclosure. Additionally, it should be noted that for the sake of description, only the parts related to the present disclosure are shown in the drawings.

[0035] Existing wafer inspection equipment only inspects wafers in a single lighting environment, making it difficult to capture multi-dimensional defect information on the wafer surface under different optical conditions; or it is necessary to perform scanning processes in different directions step by step in different lighting environments, resulting in an extended inspection cycle, making it difficult to synchronously obtain multi-dimensional image data of the front and back sides, and the inspection efficiency is relatively low.

[0036] To solve the above technical problems, this embodiment provides a wafer inspection equipment.

[0037] Figure 1 is a perspective view of a wafer inspection equipment according to an embodiment of the present disclosure, Figure 2 is a top view of a wafer inspection equipment according to an embodiment of the present disclosure, Figure 3 is a perspective view of a double-sided inspection unit according to an embodiment of the present disclosure, Figure 4 is a perspective view of a double-sided inspection unit after removing the wafer and some components according to an embodiment of the present disclosure, Figure 5 is a structural schematic diagram of a double-sided inspection unit according to an embodiment of the present disclosure.

[0038] As Figures 1 to 5 shown, the wafer inspection equipment provided in this embodiment includes: a double-sided inspection unit 100, and the double-sided inspection unit 100 includes: a scanning stage 110, a front optical imaging module 120, a back optical imaging module 130, and a stage base 140.

[0039] As Figure 4 and Figure 5 shown, the scanning stage 110 is used to place the wafer and move linearly in the first direction. Taking the Y-axis direction as an example for the above first direction, a slide rail 141 extending in the Y-axis direction is provided on the stage base 140, and the scanning stage 110 is connected to the slide rail 141 through a first slider 142. A ball screw module 143 driven by a motor and connected to the scanning stage 110 is installed on the stage base 140, and the scanning stage 110 is driven to move in the Y-axis direction through the ball screw module 143.

[0040] As Figure 5As shown, the front optical imaging module 120 and the back optical imaging module 130 are respectively arranged on opposite sides of the scanning stage 110. The front optical imaging module 120 is provided with a front bright-field light source 121 and a front dark-field light source 122, and the back optical imaging module 130 is provided with a back bright-field light source 131 and a back dark-field light source 132. Exemplarily, the front optical imaging module 120 and the back optical imaging module 130 are respectively arranged above and below the scanning stage 110, and each is provided with a lens for taking pictures to generate images.

[0041] Among them, when the scanning stage 110 moves in the positive direction of the first direction, the front bright-field light source 121 and the back bright-field light source 131 are turned on synchronously. The front optical imaging module 120 generates a bright-field image of the front side of the wafer, and the back optical imaging module 130 generates a bright-field image of the back side of the wafer; when the scanning stage 110 moves in the negative direction of the first direction, the front dark-field light source 122 and the back dark-field light source 132 are turned on synchronously. The front optical imaging module 120 generates a dark-field image of the front side of the wafer, and the back optical imaging module 130 generates a dark-field image of the back side of the wafer.

[0042] As Figure 3 and Figure 4 shown, for the convenience of placing the wafer, exemplarily, a through hole 111 is provided in the middle of the scanning stage 110, and a plurality of support plates 112 are arranged in a circular pattern inside the through hole 111. The support plates 112 are arranged at intervals, and the interval is greater than the size of a single support plate 112. The wafer is placed on the support plates 112. The support plates 112 of the scanning stage 110 block some areas of the back side of the wafer.

[0043] As Figures 3 to 5As shown in the figure, to solve the problem of the back side of the wafer being blocked, the wafer inspection device further includes a rotary lifting device 150. The rotary lifting device 150 is disposed below the scanning stage 110. After the scanning stage 110 moves in the positive and negative directions of the first direction, the rotary lifting device 150 lifts the wafer and rotates it by a first angle, so that a partial area of the back side of the wafer blocked by the scanning stage 110 is exposed. The backside optical imaging module 130 generates a bright-field image and a dark-field image of the rotated back side of the wafer, and generates a complete backside image of the wafer by stitching the images before and after the rotation of the back side of the wafer. The problem of the back side of the wafer being blocked by the scanning stage 110 is solved by the rotary lifting device 150. The scanning stage 110 usually needs to fix the wafer by mechanical clamping or vacuum adsorption to achieve stable movement. Since the clamping component of the stage will directly contact the surface of the wafer, the edge or local area of the wafer is blocked by the structure of the stage itself during the first scan, so that this area cannot be directly imaged by the backside inspection lens group. By rotating the wafer by a first angle, such as 90° or 180°, by the rotary lifting shaft 151 and performing a secondary scan, the originally blocked area can be exposed within the detection field of view, and finally the blind area can be eliminated through image stitching technology to achieve complete coverage inspection of the back side of the wafer.

[0044] The rotary lifting device 150 can use existing modules with rotary and lifting functions. The actions of lifting and rotating the wafer can be performed sequentially or synchronously. For example Figure 4 and Figure 5As shown, the rotation and lifting device 150 can also achieve the rotation and lifting functions through the following embodiments. Specifically, the rotation and lifting device 150 includes a rotation and lifting shaft 151 located below the scanning stage, a lifting drive mechanism 152 for lifting the rotation and lifting shaft 151, and a rotation drive mechanism 153 for rotating a first angle after the rotation and lifting shaft 151 is lifted. Exemplarily, the rotation drive mechanism 153 is installed on the lifting component of the lifting drive mechanism 152, and the rotation and lifting shaft 151 is installed on the rotating component of the rotation drive mechanism 153. An adsorption plate 154 for fixing the wafer is provided at the top of the rotation and lifting shaft 151. The adsorption plate 154 can be a vacuum chuck, an electrostatic chuck, etc. During operation, the rotation and lifting shaft 151 fixes the wafer by installing the adsorption plate 154, keeping the wafer stable during the lifting and rotation processes. After the wafer is lifted, it is separated from the support plate 112. After rotation, it is placed back on the support plate 112. At this time, the area on the back of the wafer that was originally blocked by the support plate 112 is exposed between the support plates 112 and can be captured by the lens of the backside optical imaging module 130. The lifting drive mechanism 152 can use a linear module, such as a ball screw module 143 combined with a servo motor or a linear motor, and cooperate with a guiding mechanism 155 to achieve the lifting action in the vertical direction, ensuring that the wafer is lifted and separated from the scanning stage 110. The rotation drive mechanism 153 can be driven by an independent servo motor through a reducer to rotate the rotating table around the Z-axis. The rotation angle is controlled by real-time feedback from an encoder to achieve the rotation of the rotation and lifting shaft 151 and the wafer.

[0045] Compared with the prior art, the wafer inspection device in this embodiment synchronously inspects the front and back sides of the wafer through the double-sided inspection unit 100. In the wafer surface inspection, the bright-field light source and the dark-field light source are set to capture multi-dimensional defect information on the wafer surface under different optical conditions. The bright-field light source directly irradiates the wafer surface and is suitable for detecting macroscopic foreign objects, scratches, and surface dirt. Its high-brightness characteristic can clearly present the reflectivity difference on the wafer surface. The dark-field light source, through an inclined or lateral illumination method, utilizes the light scattering effect of surface micro-protrusions or depressions to enhance the imaging contrast of micro-cracks, shallow residues, and other microscopic defects. In the traditional technology, the bright-field and dark-field detections require step-by-step switching of the light sources and two independent scans, resulting in low detection efficiency. This solution automatically switches the bright / dark-field light sources when the scanning stage 110 moves forward / backward, and synchronously obtains the bright-field and dark-field image data of the front and back sides of the wafer in a single round-trip scan, solving the problem of low efficiency in step-by-step detection. At the same time, according to the technical solution of one aspect of the present disclosure, this wafer inspection device does not need to be equipped with an independent flipping module, which can reduce the space occupancy of the device and avoid the risk of accidental dropping of the wafer during flipping.

[0046] Figure 6 is a three-dimensional view of a micro-measurement unit according to an embodiment of the present disclosure. As Figure 1 andFigure 6 As shown, based on the previous embodiment, the wafer inspection device provided in this embodiment further includes a microscopic measurement unit 200, and the microscopic measurement unit 200 includes: a moving stage 210, a microscopic measurement lens group 220, a lens group height adjustment mechanism 230, a marble platform 240, and a data processing module (not shown in the figure).

[0047] Specifically, an XY-axis moving shaft 241 is installed on the marble platform 240. The XY-axis moving shaft 241 can drive the moving stage 210 to move along the X-axis direction and the Y-axis direction, and the X-axis direction and the Y-axis direction are perpendicular to each other. The moving stage 210 is used to carry the wafer and is installed on the XY-axis moving shaft 241, and moves along the horizontal plane driven by the XY-axis moving shaft 241.

[0048] The microscopic measurement lens group 220 is configured to magnify the surface circuit of the wafer carried on the moving stage 210 and generate a microscopic image. The microscopic measurement lens group 220 can use an existing imaging device with the functions of magnifying the wafer surface and generating a microscopic image.

[0049] The lens group height adjustment mechanism 230 is used to drive the microscopic measurement lens group 220 to move in the vertical direction to achieve focusing. The lens group height adjustment mechanism 230 can be an existing lifting module driven by a motor, and certain movement accuracy is required. The microscopic measurement lens group 220 is installed on the lifting component of the lifting module.

[0050] Figure 7 is a schematic diagram of a wafer coordinate system according to an embodiment of the present disclosure, Figure 8 is a schematic diagram of line width calculation according to an embodiment of the present disclosure.

[0051] As Figure 7 and Figure 8 shown, the data processing module is programmed to perform the following operations: based on several feature points of the microscopic image generated by the microscopic measurement lens group 220, establish a coordinate map of the wafer surface and set the target coordinate points of the target line to be measured. In the full-automatic mode, control the moving stage 210 to move the wafer to the target coordinate point, and control the lens group height adjustment mechanism 230 to drive the microscopic measurement lens group 220 to move in the vertical direction to achieve focusing. Grab all the pixel grids of the target line in the measurement direction in the microscopic image, and calculate the number of pixel grids N. According to the number of pixel grids N and the side length S of the pixel grid, calculate the line width W = N × S.

[0052] Furthermore, the microscopic measurement unit 200 further includes a manual mode. In the manual mode, the moving stage 210 adjusts the position of the wafer manually, and the lens group height adjustment mechanism 230 adjusts the height of the microscopic measurement lens group 220 manually to achieve focusing. The data processing module captures all the pixel grids of the target circuit in the measurement direction in the microscopic image, calculates the number of pixel grids N, and calculates the line width W = N×S based on the number of pixel grids N and the side length S of the pixel grid.

[0053] Based on the double-sided detection unit 100 for double-sided detection of the wafer, the wafer detection device provided in this embodiment can automatically detect the line width on the wafer surface through the microscopic measurement unit 200. Among them, in the automatic mode, the data processing module controls the linkage of the moving stage 210, the microscopic measurement lens group 220, and the lens group height adjustment mechanism 230, without manual operation, which can improve the detection efficiency. At the same time, the microscopic measurement unit 200 is compatible with full-automatic and manual modes, and can cover different operation scenario requirements, such as mass production full-automatic mode and manual fine-tuning during the debugging period.

[0054] Figure 9 It is a perspective view of a wafer transfer module according to an embodiment of the present disclosure.

[0055] As Figure 1 and Figure 9 shown, this embodiment provides a wafer detection device. On the basis of the previous embodiment, the wafer detection device of this embodiment further includes a wafer transfer module 300, an edge finder 400, and a wafer loader 500. The wafer transfer module 300 includes: a double-arm robot 310 and a moving mechanism 320. The double-arm robot 310 includes at least two robotic arms 311. At least two robotic arms 311 are configured to alternately perform the pick-and-place actions of the wafer. The moving mechanism 320 drives the double-arm robot 310 to move linearly in the horizontal direction. The wafer loader 500 is provided with a wafer cassette 550 (as Figure 10 shown). Among them, the double-arm robot 310 is used to take out the wafer from the wafer cassette 550, transfer the wafer to the edge finder 400 for edge correction, transfer the wafer to the double-sided detection unit 100 and the microscopic measurement unit 200 in sequence, and after the wafer detection and measurement are completed, send the wafer back to the wafer cassette 550.

[0056] The wafer transfer module 300 alternately picks and places the wafer by the double robotic arms 311, reduces the waiting time, and improves the transfer efficiency. At the same time, based on the edge correction data, the transfer path is adjusted to solve the positioning error problem caused by the wafer position offset.

[0057] Based on the wafer inspection equipment provided in this embodiment that performs double-sided inspection on the wafer through the double-sided inspection unit 100 and can automatically detect the line width on the wafer surface through the microscopic measurement unit 200, the wafer transfer module 300 automatically transfers the wafer between the wafer cassette 550, the edge finder 400, the double-sided inspection unit 100, and the microscopic measurement unit 200, improving the transfer efficiency, and the accuracy of wafer movement is improved through the edge finder 400.

[0058] Existing wafer loaders lack an effective protection mechanism for the wafer cassette. When the staff makes a misoperation, it is possible to damage the wafers in the wafer cassette, that is, the phenomenon of broken wafers occurs. At the same time, the existing wafer automatic loading equipment needs to configure a horizontal movement mechanism on the opening cover assembly to drive the opening of the cover, resulting in a relatively high manufacturing cost.

[0059] Therefore, to solve the above technical problems, this embodiment provides a wafer loader 500. Figure 10 It is a perspective view of a wafer loader according to an embodiment of the present disclosure.

[0060] Figure 11 It is an exploded view of a wafer loader according to an embodiment of the present disclosure. As Figure 11 shown, the wafer loader 500 includes: a machine frame 510, a stage module 520, a baffle module 530, and an opening cover detection module 540. The machine frame 510 serves as an installation carrier for the stage module 520, the baffle module 530, and the opening cover detection module 540.

[0061] Figure 12 It is a top view of a wafer loader according to an embodiment of the present disclosure, Figure 13 is Figure 12 a sectional perspective view of the A-A section in

[0062] As Figure 12 and Figure 13 shown, the stage module 520 is disposed on the machine frame 510 and is used to fix the wafer cassette 550. The fixing method can be the same as that of the existing wafer automatic loading equipment. The stage module 520 is provided with a linear drive mechanism 521. The linear drive mechanism 521 is used to drive the wafer cassette 550 to move between the opening cover station and the inspection station. As Figure 12 shown, the area of the wafer cassette 550 with a solid line edge in the figure is the opening cover station, and the area of the wafer cassette 550 with a dashed line edge is the inspection station. The inspection station and the opening cover station are linearly arranged along the opening direction of the lid 551 of the wafer cassette 550, that is, the opening cover station is closer to the opening cover detection module 540, so that when the lid 551 of the wafer cassette 550 is fixed and the wafer cassette 550 moves from the opening cover station to the inspection station, the wafer cassette 550 can be automatically separated from the lid 551.

[0063] Figure 14 It is a perspective view of a baffle module after removing some components according to an embodiment of the present disclosure. As Figure 12 and Figure 14 shown, the baffle module 530 includes a left baffle component 531, a right baffle component 532, and a lifting baffle component 533 disposed around the stage module 520, which plays a protective role for the wafer cassette 550 to avoid accidental touch and misoperation. The left baffle component 531 and the right baffle component 532 are disposed on the machine frame 510. The lifting baffle component 533 is movably disposed between the left baffle component 531 and the right baffle component 532 in a liftable manner, and is provided with a baffle driving mechanism 534. The baffle driving mechanism 534 is disposed on the left baffle component 531 or the right baffle component 532 and is used to drive the lifting baffle component 533 to move up and down, so as to open or close the baffle module 530 to allow or prevent the operator from operating.

[0064] Figure 19 It is an exploded view of an open - cover detection module according to an embodiment of the present disclosure. As Figure 13 and Figure 19 shown, the open - cover detection module 540 includes a lifting mechanism 541, an open - cover component 542, and a detection component 543. The lifting mechanism 541 is disposed on the machine frame 510 and is connected to the open - cover component 542. The open - cover component 542 is used to fix and unlock the lid 551 of the wafer cassette 550 located at the open - cover station, and its fixing and unlocking methods can be the same as those of existing wafer automatic loading devices. The detection component 543 is disposed on the open - cover component 542 and is used to detect the wafers inside the wafer cassette 550 located at the detection station, and its detection methods can be the same as those of existing wafer automatic loading devices.

[0065] Figure 15 It is a partial perspective view of a baffle module according to an embodiment of the present disclosure. Figure 16 It is a perspective view of baffles connected in sequence through slides and sliders according to an embodiment of the present disclosure. As Figure 15 and Figure 16As shown in the figure, the left baffle assembly 531 and the right baffle assembly 532 are arranged on the machine frame 510, and the lifting baffle assembly 533 is arranged between the left baffle assembly 531 and the right baffle assembly 532 in a liftable and movable manner, which can be achieved in the following way: The left baffle assembly 531 and the right baffle assembly 532 are fixedly arranged on two opposite side surfaces of the machine frame 510, such as being fixed on the machine frame 510 by screws. Each of the left baffle assembly 531 and the right baffle assembly 532 is provided with a chute 531A, and the positions of the chutes 531A are opposite to each other. The lifting baffle assembly 533 includes at least three baffles 533A slidably arranged in the chute 531A. The baffles 533A are arranged in sequence from top to bottom and are stacked in sequence along a horizontal direction. Vertical extending slideways 533B and second sliders 533C slidably matched with the slideways 533B are respectively arranged between adjacent baffles 533A; wherein, the baffle driving mechanism 534 is connected to the uppermost baffle; among two adjacent baffles, when the upper baffle moves upward, the lower baffle is driven to move upward through the second slider 533C. When the baffle driving mechanism 534 drives the uppermost baffle to descend, the lower baffle can descend by its own weight. The baffle is slidably guided by the chute 531A, and at the same time, it is matched with the adjacent baffle through the slideway 533B and the second slider 533C. The double limit and guidance realize the stable lifting of the baffle, and the driving structure is simplified by using the upper baffle to drive the lower baffle to move, making the lifting operation of the baffle more efficient; equally importantly, the baffles can be directly stacked, which can effectively reduce the storage space required after descending and reduce space occupation; the baffle can be quickly lifted before the equipment works through lifting movement, preventing personnel from entering the working area and affecting the operation of the machine and the safety of personnel, effectively reducing the risk of fragmentation caused by misoperation of the staff.

[0066] As Figure 15As shown, in some embodiments, the baffle driving mechanism 534 is disposed on the left baffle assembly 531 or the right baffle assembly 532 and is used to drive the lifting baffle assembly 533 to move up and down, which can be achieved in the following manner: An installation plate 531B is fixedly disposed inside the left baffle assembly 531 or the right baffle assembly 532, and the installation plate 531B serves as the installation carrier of the baffle driving mechanism 534. The baffle driving mechanism 534 includes a baffle driving cylinder 534A, a connecting block 534B, a first synchronous belt 534C, a first pulley 534D, a rotating shaft 534E, a second synchronous belt 534F, and a second pulley 534G; The driving cylinder 534A is disposed on the installation plate 531B and is provided with a piston rod. The piston rod, the connecting block 534B, and the first synchronous belt 534C are fixedly connected in sequence, such as being fixedly connected by bolts. The first synchronous belt 534C is connected to two first pulleys 534D. The first pulley 534D is rotatably disposed on the installation plate 531B through a wheel shaft, and the wheel shaft of one of the first pulleys 534D is in transmission connection with the rotating shaft 534E. The connection line of the two first pulleys 534D is parallel to the piston rod. The rotating shaft 534E is rotatably disposed between the left baffle assembly 531 and the right baffle assembly 532, such as its two ends being respectively rotatably installed on bearings preset in the left baffle assembly 531 and the right baffle assembly 532. Two synchronous belt mechanisms are respectively disposed at both ends of the rotating shaft 534E, that is, two second pulleys 534G are respectively disposed at both ends of the rotating shaft 534E. One second pulley 534G is disposed above the rotating shaft 534E on each of the left baffle assembly 531 and the right baffle assembly 532. There are two second synchronous belts 534F, which are respectively connected between the rotating shaft 534E and the second pulley 534G on the left baffle assembly 531 and between the rotating shaft 534E and the second pulley 534G on the right baffle assembly 532, and the second synchronous belt 534F is connected to the uppermost baffle. Of course, the rotating shaft 534E can also be provided with only one synchronous belt mechanism to drive the baffle to lift. The beneficial effect of this driving mechanism is that through the transmission method of the synchronous belt and the pulley, the stable driving of the baffle by the baffle driving cylinder 534A is achieved. The transmission process is stable, and the lifting position of the baffle can be accurately controlled; at the same time, by being installed on the installation plate 531B of the left baffle assembly 531 or the right baffle assembly 532, the internal space of the baffle module 530 is fully utilized, the overall structural layout of the baffle module 530 is optimized, and the space occupied by the baffle module 530 is reduced.

[0067] Further, as Figure 15As shown, in an embodiment where the above-mentioned axle is in transmission connection with the rotating shaft 534E, the baffle driving mechanism 534 further includes a third synchronous belt 534H, a tension pulley 534I, and two third belt pulleys 534J. One of the third belt pulleys 534J is fixedly connected to the axle of the first belt pulley 534D, and the other third belt pulley 534J is fixedly arranged on the rotating shaft 534E. The third synchronous belt 534H is connected between the two third belt pulleys 534J. The tension pulley 534I is rotatably arranged on the mounting plate 531B and is used to tension the third synchronous belt 534H. The third synchronous belt 534H and the third belt pulleys 534J optimize the transmission unit of the baffle driving mechanism 534, making the power transmission smoother, avoiding the slipping phenomenon during the transmission process, and improving the accuracy and stability of the transmission.

[0068] It can be understood that the transmission connection between the axle and the rotating shaft 534E can also be achieved through an existing gear transmission mechanism or a chain transmission mechanism.

[0069] As Figure 15 shown, in order to improve the stability of the movement of the first synchronous belt 534C, the baffle driving mechanism 534 further includes a first guide rail 534K. The first guide rail 534K is fixedly arranged on the mounting plate 531B by bolts and is parallel to the piston rod of the baffle driving cylinder 534A. The connecting block 534B is fixedly provided with a sliding seat, and the sliding seat is slidably connected to the first guide rail 534K. The cooperation between the first guide rail 534K and the sliding seat provides an accurate guide for the movement of the connecting block 534B, enabling the connecting block 534B to move stably along a straight line under the drive of the piston rod, thus ensuring the accuracy of the movement of the baffle driving mechanism 534.

[0070] As Figure 12 shown, in some embodiments, the left baffle assembly 531, the right baffle assembly 532, the lifting baffle assembly 533, and the machine table frame 510 form a square space around the stage module 520. The square space provides good protection and positioning for the stage module 520, and can effectively prevent external factors from interfering with the stage module 520.

[0071] Figure 17 is an exploded view of a stage module and a wafer cassette according to an embodiment of the present disclosure. Figure 18 is a perspective view of the internal structure of a stage module according to an embodiment of the present disclosure. As Figure 17 and Figure 18As shown, in some embodiments of the stage module 520, the stage module 520 includes: a module base plate 522, a guide rail assembly 523, a stage assembly 524, and a fixing mechanism 525; the module base plate 522 is fixedly arranged on the machine frame 510, the guide rail assembly 523 is fixedly arranged on the module base plate 522, the stage assembly 524 is slidably arranged on the guide rail assembly 523 for placing the wafer cassette 550, the linear drive mechanism 521 includes a ball screw assembly, the ball screw assembly is fixedly arranged on the module base plate 522 and connected to the stage assembly 524 for driving the stage assembly 524 to move between the open lid station and the detection station along the guide rail assembly 523, and the fixing mechanism 525 is arranged on the stage assembly 524 and can be a snap component for fixing the wafer cassette 550 on the stage assembly 524. Among them, the snap component can use an existing electric or pneumatic snap mechanism, which will not be elaborated here. The module base plate 522 provides a stable support foundation for the entire stage module 520, and the cooperation of the guide rail assembly 523 and the ball screw assembly enables the stage assembly 524 to move accurately and smoothly between the open lid station and the detection station, improving the positioning accuracy and movement efficiency of the wafer cassette 550. The setting of the snap component ensures the fixation of the wafer cassette 550 on the stage assembly 524, avoiding the shaking or falling off of the wafer cassette 550 during the movement, and ensuring the smooth progress of the transfer and detection processes.

[0072] It can be understood that the fixing mechanism 525 can also be a fixture or a vacuum chuck.

[0073] As Figure 19 shown, in some embodiments of the above-mentioned lifting mechanism 541, the lifting mechanism 541 is a ball screw module and is installed on the module backplane 544, its moving end is connected to the open lid component 542, and the module backplane 544 is fixed on the machine frame 510.

[0074] Figure 20 is a perspective view of the internal structure of the open lid component according to an embodiment of the present disclosure. As Figure 20As shown, in some embodiments of the above-mentioned lid opening assembly 542, the lid opening assembly 542 includes a fixing assembly 542A for fixing the lid 551, an unlocking assembly for unlocking the lid 551, and a fitting plate 542B for mounting the fixing assembly 542A and the unlocking assembly. Among them, the fixing assembly 542A can be a vacuum chuck or a fixture. The unlocking assembly includes at least two key pins 542C rotatably arranged on the fitting plate 542B, a connecting rod assembly connected to the two key pins 542C, and an unlocking cylinder 542D connected to the connecting rod assembly; the connecting rod assembly includes a first rotating rod 542E, a second rotating rod 542F, and an intermediate rod 542G. Two ends of the first rotating rod 542E are respectively hinged to the piston rod of the unlocking cylinder 542D and one end of the intermediate rod 542G, and the middle part of the first rotating rod 542E is connected to an unlocking pin. One end of the second rotating rod 542F is connected to the unlocking pin, and the other end is fixedly connected to one end of the intermediate rod 542G; wherein, the first rotating rod 542E and the second rotating rod 542F are parallel to each other, the intermediate rod 542G and the piston rod of the unlocking cylinder 542D are parallel to each other, and are arranged in a parallelogram. The two key pins 542C are arranged at the middle positions of the opposite sides of the parallelogram. During operation, the wafer cassette 550 moves to the lid opening station. The fixing assembly 542A stably fixes the lid 551. The key pins 542C are inserted into the keyholes of the lid 551. By driving the connecting rod assembly with the unlocking cylinder 542D, the key pins 542C are driven to rotate, realizing the unlocking operation of the lid 551. Compared with the traditional unlocking mechanism with worm and worm gear transmission, the lid opening assembly 542 of the present application simplifies the overall structure through the parallelogram structure of the connecting rod assembly, and makes the rotation of the key pins 542C more stable and accurate, improving the success rate and reliability of lid opening.

[0075] Figure 21 is a perspective view of a detection component according to an embodiment of the present disclosure. Figure 22 is a perspective view of a track groove according to an embodiment of the present disclosure. As Figure 21 and Figure 22As shown, in some embodiments of the above-mentioned detection component 543, the detection component 543 includes a detection frame 543A, a telescopic cylinder 543B, and a detection sensor 543C; the detection frame 543A is rotatably arranged on the lid opening component 542, for example, connected to the fitting plate 542B of the lid opening component 542 through a rotating shaft. An arc-shaped track groove 543D is arranged at the bottom of the detection frame 543A. The telescopic cylinder 543B is fixedly arranged on the lid opening component 542, and its piston rod is provided with a roller 543E. The roller 543E is arranged inside the track groove 543D; the detection sensor 543C is arranged at the top of the detection frame 543A; wherein, when the piston rod of the telescopic cylinder 543B moves, the roller 543E pushes the groove wall of the track groove 543D to rotate the detection frame 543A, so that the detection sensor 543C moves from the outside of the wafer cassette 550 to the inside or from the inside of the wafer cassette 550 to the outside. By driving the roller 543E to move in the track groove 543D by the telescopic cylinder 543B, the rotation of the detection frame 543A is realized, and then the detection sensor 543C is driven to extend into the wafer cassette 550. At the same time, by driving the detection sensor 543C to move up and down by the lifting mechanism 541, the inside and outside of the wafer cassette 550 can be conveniently detected. After the detection, the telescopic cylinder 543B drives the roller 543E to move in the reverse direction, so that the detection frame 543A rotates in the reverse direction and resets the detection sensor 543C.

[0076] In this embodiment, a control method for a wafer loader is provided. The control method is used to control the wafer loader of any one of the above, and includes the following steps: after the wafer cassette 550 is placed on the stage module 520, the baffle driving mechanism 534 drives the lifting baffle assembly 533 to rise; the stage module 520 fixes the wafer cassette 550 at the detection station; the linear driving mechanism 521 drives the wafer cassette 550 to advance from the detection station to the lid opening station; the lid opening component 542 fixes and unlocks the lid 551 of the wafer cassette 550 located at the lid opening station; the linear driving mechanism 521 drives the wafer cassette 550 to retreat from the lid opening station to the detection station, separates the wafer cassette 550 from the lid 551, and enables the lifting movement of the lid opening component 542 and the detection component 543 to be not interfered by the wafer cassette 550; the lifting mechanism 541 controls the lifting movement of the detection component 543, and the detection component 543 detects the wafers located inside the wafer cassette 550.

[0077] Exemplarily, the wafer loader of the present application is used for a wafer loader, and the wafer loader adopts the control of the positive motion Base + ladder diagram language. The control of the positive motion Base + ladder diagram language is a programming method for industrial automation, which combines the efficiency of the Base language and the intuitiveness of the ladder diagram language. The advantages of the combination of Base + ladder diagram are as follows: the combination of flexibility and intuitiveness: the Base language processes complex logic, and the ladder diagram language processes simple logic, improving the development efficiency and system performance; modular design: supports modular programming, facilitating function reuse and maintenance; good real-time performance: suitable for real-time control, capable of quickly responding to input signals and performing operations. Its action process is as follows: start, initialization, wait for personnel or an overhead crane to place the wafer cassette 550, recipe selection, loading process, the manipulator picks and places wafers, unloading process, wait for personnel or an overhead crane to take away the wafer cassette 550, end. Specifically, initialization: the system starts up, performs self-check and initialization settings. Wait for personnel or an overhead crane to place the wafer cassette 550: the system waits for the wafer cassette 550 to be placed at the designated position. Recipe selection: select the corresponding processing recipe according to the model or category of the wafer cassette 550.

[0078] Exemplarily, the loading process is as follows: the baffle rises: the baffle rises to prevent personnel from entering the working area and affecting the operation of the machine and personnel safety; the wafer cassette is fixed: the fixing mechanism 525 uses a buckle assembly, a fixture or a vacuum chuck to fix the wafer cassette to prevent the wafer cassette 550 from moving during subsequent operations, and confirm that the wafer cassette 550 is firmly fixed; the wafer cassette 550 advances: the wafer cassette 550 advances from the initial position to the lid opening station to ensure that the wafer cassette 550 accurately reaches the working area of the lid opening assembly 542; the lid opening assembly 542 sucks vacuum: the vacuum chuck of the lid opening assembly 542 is activated to suck the lid 551 of the wafer cassette 550, confirm that the chuck firmly fixes the lid 551, and the key pin 542C is inserted into the keyhole of the lid 551; unlock the lid 551: the key pin 542C rotates to unlock the buckle of the lid 551, confirm complete unlocking, and the lid 551 can be opened; the wafer cassette 550 retreats: the wafer cassette 550 retreats from the lid opening position, and the door of the wafer cassette 550 is pulled open under the action of the vacuum chuck to complete the lid opening operation.

[0079] Exemplarily, the unloading process is as follows: the wafer cassette 550 retracts, the Map process, the wafer cassette 550 advances, the lid 551 is locked, the wafer cassette 550 retracts, the wafer cassette 550 is released, and the baffle descends. Specifically, for the wafer cassette 550 to retract: the wafer cassette 550 retracts from the unloading position to the detection station to ensure that the lifting movement of the lid opening assembly 542 is not affected; Map process: execute the Map operation process; the wafer cassette 550 advances: the wafer cassette 550 advances to the lid opening position to ensure that the wafer cassette 550 accurately reaches the working area of the lid opening assembly 542, the lid 551 enters the wafer cassette 550, and the key pin 542C is inserted into the keyhole; lock the lid 551: the key pin 542C rotates to tightly lock the buckle of the wafer cassette 550, confirm that the lid 551 is tightly locked on the wafer cassette 550, and the vacuum suction cup releases the adsorption of the lid 551; the wafer cassette 550 retracts: the wafer cassette 550 retracts to the initial position and enters the operation area of personnel (or overhead crane); release the wafer cassette 550: the fixing mechanism 525 cancels the fixation of the wafer cassette 550; the baffle descends: the baffle driving mechanism 534 drives the baffle 533A to descend to ensure that the wafer cassette 550 can be safely picked up and placed in the transfer area.

[0080] The above Map process is as follows: the lid opening assembly 542 descends to the starting position: the lid opening assembly 542 descends from the current position to the starting position of the Mapping scan to ensure that the lid opening assembly 542 does not interfere with the operation of the detection assembly 543; the detection assembly 543 extends: the telescopic cylinder 543B drives the detection frame 543A to rotate, so that the detection sensor 543C extends into the wafer cassette 550 to confirm that the detection mechanism reaches the starting position of the scan; the lid opening assembly 542 descends to the ending position: the lid opening assembly 542 continues to descend from the starting position to the ending position of the Mapping scan. During the descent, the detection sensor 543C scans the inside of the wafer cassette 550; latch the calculation result of the data: after the scan is completed, the system latches the detection data, analyzes the latched data to analyze whether the product is laminated or skewed (whether there is inclination or incorrect position), and generates a status report of the inside of the wafer cassette 550 according to the calculation result; the detection assembly 543 retracts: the detection sensor 543C retracts from the inside of the wafer cassette 550 and returns to the initial position to confirm that the detection mechanism is completely retracted to avoid interfering with subsequent operations.

[0081] In summary, the wafer loader of the present application improves the protection of wafers through the baffle module 530. After the wafer cassette 550 is placed on the stage module 520, the baffle driving mechanism 534 drives the lifting baffle assembly 533 to rise, so that the left baffle assembly 531, the right baffle assembly 532, and the lifting baffle assembly 533 are arranged around the stage module 520 to form a protection structure to protect the wafer cassette 550 and prevent fragmentation caused by misoperation. The wafer loader of the present application reduces the manufacturing cost through the coordinated action of the stage module 520 and the lid opening detection module 540. After the lid opening assembly 542 fixes and unlocks the lid 551 of the wafer cassette 550 at the lid opening station, the linear driving mechanism 521 drives the wafer cassette 550 to retreat from the lid opening station to the detection station, separates the wafer cassette 550 from the lid 551, and enables the lifting movement of the lid opening assembly 542 and the detection assembly 543 to be not interfered by the wafer cassette 550. Compared with the existing wafer automatic loading equipment, the wafer loader of the present application does not need to configure a horizontal movement mechanism on the lid opening assembly 542 to open the lid 551. Instead, it uses the horizontal driving mechanism of the stage module 520 to drive the wafer cassette 550 to move, thereby opening the lid 551. That is, the horizontal driving mechanism simultaneously has the functions of driving the wafer cassette 550 to move between the detection station and the lid opening station and opening the lid 551 of the wafer cassette 550. When the wafer cassette 550 retreats to the detection station, the lid opening action can be completed synchronously. In this way, the wafer loader of the present application can save the use of the horizontal driving mechanism, thereby reducing the manufacturing cost.

[0082] This embodiment discloses a detection method for a wafer detection device, including the following steps: placing a wafer on the scanning stage 110; the scanning stage 110 moves in the positive direction of the first direction, and the front bright-field light source 121 and the back bright-field light source 131 are turned on synchronously. The front optical imaging module 120 generates a bright-field image of the front side of the wafer, and the back optical imaging module 130 generates a bright-field image of the back side of the wafer; when the scanning stage 110 moves in the negative direction of the first direction, the front dark-field light source 122 and the back dark-field light source 132 are turned on synchronously. The front optical imaging module 120 generates a dark-field image of the front side of the wafer, and the back optical imaging module 130 generates a dark-field image of the back side of the wafer; comparing the bright-field images and dark-field images of the front and back sides of the wafer with the standard wafer image template to determine whether there are defects or foreign matter stains on the wafer surface.

[0083] The detection method of this embodiment completes the acquisition of double-sided bright-field and dark-field images synchronously through a single round-trip of the scanning stage 110. Compared with the traditional step-by-step detection that requires 4 single-direction scans, the detection efficiency is improved, especially suitable for mass production scenarios. The double-sided optical imaging module works synchronously without flipping the wafer, reducing the risk of wafer damage. By combining bright-field and dark-field multi-modal detection, various defects on the front and back sides of the wafer can be identified, and the missed detection rate can be reduced.

[0084] Further, to avoid undetected cases caused by the back side of the wafer being blocked, the detection method further includes the following steps: after the scanning stage 110 moves in the positive and negative directions of the first direction, lift the wafer and rotate it by a first angle to expose a partial area of the back side of the wafer blocked by the scanning stage 110; the backside optical imaging module 130 generates a bright-field image and a dark-field image of the rotated back side of the wafer, and generates a complete backside image of the wafer by stitching the images before and after the rotation of the back side of the wafer. By rotating the wafer to expose the area blocked by the scanning stage 110, the backside detection of the wafer is fully covered, ensuring image integrity.

[0085] In addition, to detect the line width on the surface of the wafer, the detection method further includes the following steps: place the wafer on the moving stage 210; based on a number of feature points of the microscopic image generated by the microscopic measurement lens group 220, the data processing module establishes a coordinate map of the wafer surface and sets the target coordinate points of the target line to be measured; control the moving stage 210 to move the wafer to the target coordinate points, and control the lens group height adjustment mechanism 230 to drive the microscopic measurement lens group 220 to move in the vertical direction to achieve focusing; capture all the pixel grids of the target line in the measurement direction in the microscopic image, and calculate the number of pixel grids N. According to the number of pixel grids N and the side length S of the pixel grid, calculate the line width W = N × S. The detection method of the present disclosure establishes a coordinate map through the feature points of the micro-image and eliminates the influence of optical distortion through the pixel grid calibration algorithm (W = N × S), which can improve the measurement accuracy. The coordinated control of autofocus and stage movement can shorten the measurement time and improve the overall efficiency.

[0086] Those skilled in the art should understand that the above embodiments are only for clearly explaining the present disclosure, rather than limiting the scope of the present disclosure. For those skilled in the art, other changes or variations can be made based on the above disclosure, and these changes or variations are still within the scope of the present disclosure.

Claims

1. A wafer inspection device, characterized in that, Comprising: A double-sided detection unit, the double-sided detection unit comprising: A scanning stage for placing a wafer and linearly moving in a first direction; and A front optical imaging module and a back optical imaging module, respectively arranged on opposite sides of the scanning stage. The front optical imaging module is provided with a front bright-field light source and a front dark-field light source, and the back optical imaging module is provided with a back bright-field light source and a back dark-field light source; Wherein, when the scanning stage moves in the positive direction of the first direction, the front bright-field light source and the back bright-field light source are synchronously turned on, the front optical imaging module generates a bright-field image of the front side of the wafer, and the back optical imaging module generates a bright-field image of the back side of the wafer; when the scanning stage moves in the negative direction of the first direction, the front dark-field light source and the back dark-field light source are synchronously turned on, the front optical imaging module generates a dark-field image of the front side of the wafer, and the back optical imaging module generates a dark-field image of the back side of the wafer.

2. The wafer inspection device according to claim 1, wherein The front optical imaging module and the back optical imaging module are respectively arranged above and below the scanning stage; the scanning stage blocks a partial area of the back side of the wafer; The wafer detection device further includes a rotary lifting device, the rotary lifting device is arranged below the scanning stage, and after the scanning stage moves in the positive direction and the negative direction of the first direction, the rotary lifting device lifts the wafer and rotates by a first angle to expose a partial area of the back side of the wafer blocked by the scanning stage; The back optical imaging module generates a bright-field image and a dark-field image of the rotated back side of the wafer, and generates a complete back-side image of the wafer by stitching the images of the back side of the wafer before and after rotation.

3. The wafer inspection device according to claim 2, characterized in that, The rotary lifting device includes a rotary lifting shaft located below the scanning stage, a lifting drive mechanism for lifting the rotary lifting shaft, and a rotary drive mechanism for rotating by a first angle after the rotary lifting shaft is lifted. An adsorption plate for fixing the wafer is arranged at the top of the rotary lifting shaft.

4. The wafer inspection device according to claim 1, wherein The wafer detection device further includes a microscopic measurement unit, the microscopic measurement unit comprising: A moving stage for carrying the wafer and moving on a horizontal plane; A microscopic measurement lens group configured to magnify the surface circuit of the wafer carried on the moving stage and generate a microscopic image; A lens group height adjustment mechanism for driving the microscopic measurement lens group to move in the vertical direction to achieve focusing; and A data processing module programmed to perform the following operations: Establish a surface coordinate map of the wafer based on the microscopic image generated by the microscopic measurement lens group, and set target coordinate points of the target circuit to be measured; In the full-automatic mode, control the moving stage to move the wafer to the target coordinate point, and control the lens group height adjustment mechanism to drive the microscopic measurement lens group to move in the vertical direction to achieve focusing; Grab all pixel grids of the target circuit in the measurement direction in the microscopic image, calculate the number of pixel grids N, and calculate the line width W = N×S according to the number of pixel grids N and the side length S of the pixel grid.

5. The wafer inspection device according to claim 4, wherein The position of the wafer is adjusted manually by the moving stage, and the height of the microscopic measurement lens group is adjusted manually by the lens group height adjustment mechanism to achieve focusing.

6. The wafer inspection device according to claim 4, wherein, The wafer detection device further includes a wafer transfer module and an edge finder. The wafer transfer module includes: A dual-arm manipulator, including at least two robotic arms, and the two robotic arms are configured to alternately perform wafer picking and placing actions; and A moving mechanism, which drives the dual-arm manipulator to move linearly in the horizontal direction; Wherein, the dual-arm manipulator is used to take out the wafer from the wafer cassette, transfer the wafer to the edge finder to complete edge correction, transfer the wafer to the double-sided detection unit and the micro measurement unit in sequence, and after the wafer detection and measurement are completed, send the wafer back to the wafer cassette.

7. The wafer inspection apparatus according to claim 6, wherein The wafer detection device further includes a wafer loader, and the wafer cassette is provided on the wafer loader.

8. A wafer detection method, which is implemented by using the wafer detection device according to any one of claims 1 to 7, characterized in that The wafer detection method includes the following steps: Place the wafer on the scanning stage; The scanning stage moves in the positive direction of the first direction, the front bright-field light source and the back bright-field light source are turned on synchronously, the front optical imaging module generates a bright-field image of the front side of the wafer, and the back optical imaging module generates a bright-field image of the back side of the wafer; When the scanning stage moves in the negative direction of the first direction, the front dark-field light source and the back dark-field light source are turned on synchronously, the front optical imaging module generates a dark-field image of the front side of the wafer, and the back optical imaging module generates a dark-field image of the back side of the wafer; Compare the bright-field images and dark-field images of the front and back sides of the wafer with the standard wafer image template.

9. The wafer inspection method according to claim 8, wherein It further includes the following steps: After the scanning stage moves in the positive and negative directions of the first direction, lift the wafer and rotate it by a first angle to expose a partial area of the back side of the wafer blocked by the scanning stage; the back optical imaging module generates a bright-field image and a dark-field image of the rotated back side of the wafer, and generates a complete back-side image of the wafer by stitching the images before and after the rotation of the back side of the wafer.

10. The wafer inspection method according to claim 8, characterized in that, It further includes the following steps: Place the wafer on the moving stage; The data processing module establishes a wafer surface coordinate map based on the microscopic image generated by the micro measurement lens group, and sets the target coordinate points of the target line to be measured; Control the moving stage to move the wafer to the target coordinate point, and control the lens group height adjustment mechanism to drive the micro measurement lens group to move in the vertical direction to achieve focusing; Grab all the pixel grids of the target line in the measurement direction in the microscopic image, calculate the number of pixel grids N, and calculate the line width W = N×S according to the number of pixel grids N and the side length S of the pixel grid.

Images