Acoustic microscope imaging device and method

Abstract

The invention belongs to the technical field of nondestructive testing and ultrasonic imaging, and particularly relates to an acoustic microscope imaging device and method.The device comprises a control module, a rotating platform, an ultrasonic probe, a radial feeding mechanism and an angle sensing unit, and the rotating platform, the ultrasonic probe, the radial feeding mechanism and the angle sensing unit are connected with the control module. The angle sensing unit is arranged on the rotating platform and used for collecting rotating angle information of the rotating platform; the ultrasonic probe is fixed on the radial feeding mechanism and is positioned right above the sample to be detected; the control module is used for controlling the radial feeding mechanism to drive the ultrasonic probe to move multiple times in the radial direction of the rotating platform, controlling the rotating platform to drive the to-be-tested sample to rotate to form a circular track, and controlling the ultrasonic probe to scan and collect echo signals of the to-be-tested sample on the circular track in the rotating process. And generating a plane image of the to-be-tested sample. According to the invention, the ultrasonic signal stability, the imaging accuracy and the scanning efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of non-destructive testing and ultrasonic imaging, and more particularly, relates to an acoustic microscope imaging device and method. BACKGROUND

[0002] A scanning acoustic microscope (SAM) is a non-destructive testing device that uses ultrasonic pulse echo to visualize the internal structure of a material. Traditional scanning acoustic microscopes usually use a mechanical line-by-line scanning method. This method has obvious disadvantages when imaging large samples (such as a 12-inch semiconductor wafer) at high resolution: the scanning range is large, the pixel density is high, and the processing time is long (up to 10 hours per piece). Due to the need for scanning accuracy, the transducer and its carrier need to be accelerated and decelerated frequently during high-speed reciprocating motion. The inertia and vibration of the motion mechanism limit the further improvement of scanning speed. In addition, the sample is usually immersed in a coupling medium such as water during scanning, and moving the transducer will disturb the medium. Excessive movement speed may cause water splashes and bubbles to affect signal stability.

[0003] To improve scanning efficiency, there are currently various improvement schemes. For example, a high-speed scanning acoustic microscope uses multi-transducer parallel scanning, installs multiple (such as four) ultrasonic sensors on the scanning module to work simultaneously, greatly shortens the scanning beat time, and can increase the detection speed by about 4 to 5 times. However, the multi-channel parallel scheme increases the complexity and cost of the system, and the calibration and synchronization of multiple probes are more difficult. High-speed rotary scanning is a feasible means to solve this technical bottleneck, which has the advantages of no need to frequently accelerate and decelerate during scanning, minimal vibration, and no need to consider the rigidity of moving parts. However, the devices that can achieve high-speed rotary scanning still have the following problems: 1) When the ultrasonic probe moves at high speed in water, it is affected by the resistance of the water. If the rigidity of the probe holder is not enough, it will vibrate, and the resulting image will have ripples, causing image distortion; 2) When the ultrasonic probe moves at high speed in water, the turbulence in the water will greatly affect the imaging effect; 3) The existing device is difficult to apply to high-frequency application scenarios and is only suitable for low-frequency application scenarios.

[0004] Therefore, there is an urgent need for a new technical solution to achieve high-speed ultrasonic scanning and imaging of large planar samples with a simpler and more efficient structure, while ensuring image quality and system reliability. SUMMARY

[0005] In view of the defects of the prior art, the purpose of the present application is to provide an acoustic microscope imaging device, which aims to solve the problems of unstable ultrasonic signals, low scanning efficiency and poor imaging accuracy in existing acoustic microscopic imaging technology.

[0006] To achieve the above objectives, in a first aspect, this application provides an acoustic microscope imaging device, including a control module, and a rotating platform, an ultrasonic probe, a radial feed mechanism, and an angle sensing unit respectively connected to the control module, wherein: the rotating platform is used to carry the sample to be tested; the angle sensing unit is disposed on the rotating platform and is used to collect the rotation angle information of the rotating platform; the ultrasonic probe is fixed on the radial feed mechanism and is located directly above the sample to be tested; the control module is used to control the radial feed mechanism to drive the ultrasonic probe to move multiple times radially along the rotating platform, and after each movement, control the rotating platform to drive the sample to be tested to rotate to form a circular trajectory, and is also used to control the ultrasonic probe to scan and collect the echo signal of the sample to be tested on the circular trajectory during the rotation, and use all the echo signals on multiple circular trajectories to generate a planar image of the sample to be tested.

[0007] Furthermore, the ultrasonic probe is equipped with a coupling medium spraying module, which is used to spray the coupling medium onto the sample under test during ultrasonic scanning to form a liquid connection bridge between the ultrasonic probe and the sample under test.

[0008] Furthermore, the ultrasonic probe operates at a frequency of 15MHz to 500MHz.

[0009] Furthermore, the radial feed mechanism includes a guide rail, a precision linear slide, and a servo motor drive unit. The guide rail is arranged radially above the rotary platform. The precision linear slide is mounted on the guide rail and can slide back and forth relative to the guide rail. The servo motor drive unit is connected to the precision linear slide and is used to provide sliding power for the precision linear slide.

[0010] Furthermore, multiple ultrasonic probes are provided, and the multiple ultrasonic probes are evenly arranged to form a circular array, with each ultrasonic probe facing the sample to be tested.

[0011] Furthermore, the stroke of the radial feed mechanism driving the ultrasonic probe is not less than the radius of the sample to be tested.

[0012] Furthermore, the spacing between adjacent circular trajectories is equal.

[0013] Furthermore, the rotating platform is equipped with a vacuum adsorption unit or a mechanical clamp, which is used to fix the sample to be tested.

[0014] Furthermore, the acquisition accuracy of the angle sensing unit is less than ±5 arcseconds.

[0015] According to a second aspect of this application, a method for imaging a sample to be tested using an acoustic microscope imaging device as described above is provided, comprising: S1 controls the angle sensing unit to collect the rotation angle information of the rotating platform; controls the radial feed mechanism to drive the ultrasonic probe to move along the radial direction of the rotating platform to the scanning start position according to the preset step distance; Based on the rotation angle information, S2 controls the rotating platform to drive the sample to be tested to rotate at a preset angular velocity until a circular trajectory is formed. During the rotation, the ultrasonic probe is controlled to continuously scan and collect the echo signals at each position of the sample to be tested on the circular trajectory until the circular trajectory is completely scanned and then the scanning stops. S3 repeats steps S1-S2 to obtain multiple echo signals on multiple circular trajectories, and uses all echo signals to generate a planar image of the sample under test.

[0016] Furthermore, the echo signal is stored in polar coordinate format.

[0017] Furthermore, in step S3, a coordinate transformation method is used to convert all polar coordinate format echo signals into rectangular coordinate images.

[0018] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0019] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) This application achieves continuous scanning of the sample by rotating the sample while the ultrasonic probe remains stationary, eliminating the frequent acceleration and deceleration processes in traditional linear reciprocating scanning, improving the stability of the ultrasonic signal, and significantly shortening the imaging time required for the entire sample. The high-precision angle sensing unit acquires the rotation angle position information of the rotating platform, ensuring that the timing of the probe's emission of sound waves and acquisition of echoes strictly corresponds to the sample's angle position. Each pixel has definite position coordinates and depth information. Even at high rotation speeds, the system can sample with constant angle increments, avoiding imaging blur caused by inaccurate positioning and improving imaging accuracy. Especially for samples such as large wafers, high-resolution imaging can be completed within minutes, with high imaging efficiency, meeting the requirements of high-speed online inspection in production lines. (2) The ultrasonic probe of this application is mounted on the radial feed mechanism and only needs to follow the radial feed mechanism to perform a small range of radial linear movement. By limiting the large movement of the ultrasonic probe, the risk of accidental collision or damage to the ultrasonic probe is avoided. The rotating platform carries the sample to be tested and rotates around its central axis. The motion resistance is small and the stability is high. Overall, this application has fewer moving parts and a compact structure, thus further improving the system reliability and lifespan.

[0020] (3) This application sets a coupling medium spraying module on the ultrasonic probe. The coupling medium spraying module can spray the coupling medium towards the sample to be tested when the ultrasonic probe scans the sample to be tested, so as to form a liquid connection bridge between the ultrasonic probe and the sample to be tested. The liquid connection bridge is a continuous water column, the ultrasonic coupling path is more stable, and the ultrasonic signal is also more stable.

[0021] (4) This application can arrange multiple ultrasound probes into a ring array to work in parallel. Multiple probes can simultaneously collect signals from different angle ranges during the formation of each circular trajectory, which is equivalent to acquiring multiple concentric scanning lines at the same time, thereby multiplying the scanning efficiency. The data of each channel is uniformly and synchronously fused and processed by the control system. The resolution and field of view of the final image are not affected, and the imaging efficiency is higher.

[0022] (5) This application takes into account the combined effects of various factors such as structural vibration, coupling path stability, and scanning efficiency through structural optimization design, so that this application can operate in high frequency application scenarios between 15MHz and 500MHz.

[0023] (6) This application uses continuous scanning to obtain the original data of the entire sample to be tested and stores it in polar coordinate format. There is no interface problem of data splicing after block scanning, which avoids artifacts and errors caused by image splicing. At the same time, it can be combined with real-time coordinate transformation algorithm to obtain a complete and continuous rectangular coordinate image corresponding to the actual sample, so as to achieve accurate positioning of defects. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of an acoustic microscope imaging device provided in Embodiment 1 of this application; Figure 2 This is a top view schematic diagram of an acoustic microscope imaging device provided in Embodiment 1 of this application; Figure 3 This is a schematic diagram of an acoustic microscope imaging process provided in Embodiment 2 of this application; Figure 4 This is a schematic diagram of the structure of an electronic device provided in Embodiment 3 of this application.

[0025] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-Rotating platform, 2-Ultrasonic probe, 21-Coupled medium spray module, 3-Radial feed mechanism, 4-Control module, 5-Angle sensing unit. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] In this article, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0028] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0029] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0030] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0031] The embodiments of this application are described below with reference to the accompanying drawings.

[0032] Example 1 This embodiment provides an acoustic microscope imaging device, such as... Figure 1As shown, the imaging device includes a control module 4, and a rotating platform 1, an ultrasonic probe 2, a radial feed mechanism 3, and an angle sensing unit 5, all connected to the control module 4. The rotating platform 1 carries the sample to be tested; in this embodiment, the sample is a 12-inch semiconductor wafer. The angle sensing unit 5 is mounted on the rotating platform 1 and collects the rotation angle information of the rotating platform 1, transmitting it to the control module 4 via wires. The ultrasonic probe 2 is fixed to the radial feed mechanism 3 and positioned directly above the sample. The control module 4 controls the radial feed mechanism 3 to move the ultrasonic probe 2 multiple times along the radial direction of the rotating platform 1. After each movement, the control module 4 controls the rotating platform 1 to rotate the sample to form a circular trajectory. It also controls the ultrasonic probe 2 to scan and collect the echo signals of the sample on the circular trajectory during rotation, and uses all the echo signals from multiple circular trajectories to generate a planar image of the sample.

[0033] Specifically, a high-speed rotating motor is provided directly below the aforementioned rotating platform 1 to provide driving force. The output shaft of the high-speed rotating motor is connected to the rotating platform 1, and the control module 4 is electrically connected to the high-speed rotating motor (not shown in the figure). The rotating platform 1 is a regular shape, such as a circle or a square, and its central axis is perpendicular to the center of the semiconductor wafer located above it, thereby enabling the semiconductor wafer to rotate stably in the direction of the arrow or in the opposite direction of the arrow.

[0034] In this embodiment, the ultrasonic probe 2 is equipped with a coupling medium spray module 21, which sprays a coupling medium onto the semiconductor wafer during ultrasonic scanning to form a liquid connection bridge between the ultrasonic probe 2 and the semiconductor wafer. The coupling medium can be deionized water, which can be continuously supplied to the coupling medium spray module 21 via a pipeline (the deionized water supply pipeline is not shown in the figure). The ultrasonic probe and the semiconductor wafer are connected via deionized water, allowing ultrasonic waves to be effectively transmitted into the semiconductor wafer. Compared to the traditional full-area water tank immersion method, this application integrates a coupling medium spray module 21 on the outside of the ultrasonic probe 2, which can form a fine and stable water flow (i.e., spray coupling) at the ultrasonic transmitting end of the ultrasonic probe. Figure 1 (The dashed line in the middle represents the water flow). This creates a thin liquid bridge only below the ultrasonic probe, which satisfies ultrasonic coupling and avoids the problem of unstable ultrasonic signals caused by the agitation of a large volume of liquid when the sample is rotated at high speed in existing technologies.

[0035] In this embodiment, the aforementioned ultrasonic probe 2 is selected as a high-frequency focused ultrasonic probe and is fixedly installed on one end of the radial feed mechanism 3 facing the rotation center of the rotating platform 1. The operating frequency of the ultrasonic probe 2 is 15MHz to 500MHz, such as 15MHz, 30MHz, 50MHz, 100MHz, 175MHz, 230MHz, 250MHz, or 300MHz, or any operating frequency value between any two of the aforementioned values, and the axial resolution corresponding to the ultrasonic probe 2 can reach several micrometers, resulting in higher acquisition accuracy.

[0036] The aforementioned radial feed mechanism 3 includes a guide rail, a precision linear slide, and a servo motor drive unit (not shown in the figure). The guide rail is fixed on a frame located beside the rotating platform 1, and as shown in Figure 2, the guide rail is positioned directly above the rotating platform 1 along its radial direction. The aforementioned precision linear slide is mounted on the guide rail, and the ultrasonic probe 2 is fixed to the end of the precision linear slide near the center of the rotating platform 1, with the ultrasonic scanning end facing the rotating platform 1. The output shaft of the servo motor drive unit is connected to the precision linear slide, providing power for the precision linear slide to reciprocate in the direction of the arrow, thereby enabling the precision linear slide to drive the ultrasonic probe 2 to reciprocate relative to the guide rail.

[0037] In this embodiment, the aforementioned radial feed mechanism 3 drives the ultrasonic probe 2 to move a stroke that is not less than the radius of the semiconductor wafer, ensuring that the ultrasonic probe 2 can cover the scanning range from the center to the edge of the sample to be tested.

[0038] In this embodiment, the spacing between adjacent circular trajectories is equal; specifically, the rotating platform rotates at a constant speed of 600 rpm, and the radial feed mechanism moves intermittently at a speed of about 0.1 mm / revolution, so that the spacing between adjacent concentric circles is about 0.1 mm, which can ensure sufficient scanning coverage without omission.

[0039] In other embodiments, the density of the scanning trajectory can be changed by adjusting the ratio of the rotational speed to the radial feed speed. For example, for higher resolution requirements, the feed speed can be reduced to obtain a smaller concentric circle scanning interval; for rapid coarse detection, the step size can be appropriately increased to speed up the scanning. To achieve flexible control, the control module 4 of this imaging device has multiple sets of scanning mode parameters pre-stored, and the user can select a suitable combination of rotational speed and step size for scanning according to the sample size and detection requirements.

[0040] The aforementioned control module 4 may include major components such as an industrial control computer, an ultrasonic pulse transmitting and receiving module, a digital-to-analog converter acquisition card, and a motion controller. Specific structural design is not the focus of this application and will not be elaborated upon here. Specifically, the aforementioned control module 4 can perform closed-loop coordinated control of the servo motors of the rotating platform 1 and the radial feed mechanism 3, executing the planning and synchronization of scanning motion according to preset parameters (rotation speed, radial movement speed, sampling angle step, etc.). Regarding signals, the control module 4 triggers the probe to emit ultrasonic pulses according to the rotation angle of the rotating platform 1 acquired by the angle sensing unit 5, and performs high-speed acquisition and digital processing of the echo signals (storing the data in polar coordinate format). The control module 4 can also convert the acquired polar coordinate data into a rectangular coordinate image in real time and perform defect discrimination algorithm calculations. The control module 4 can also adjust scanning parameters according to actual needs, such as controlling the spacing between concentric scanning lines by changing the radial movement speed of the ultrasonic probe 2, thereby balancing scanning speed and image resolution. The control module 4 also includes a user interface for setting parameters such as scanning range, frequency, and depth of focus, and automatically generates a detection report after scanning is completed.

[0041] In this embodiment, a vacuum adsorption unit or mechanical clamp is also provided on the rotating platform 1. The vacuum adsorption unit or mechanical clamp is used to fix the semiconductor wafer. Both the vacuum adsorption unit and the mechanical clamp adopt existing structures and only need to be assembled with the rotating platform 1. The specific structure will not be described in detail here.

[0042] In this embodiment, the acquisition accuracy of the aforementioned angle sensing unit 5 is less than ±5 arcseconds. Specifically, the angle sensing unit can be an angle sensor or a high-precision angle position feedback component. The angle position feedback component generally includes a high-precision grating ruler, servo driver, and motion controller, etc. The specific structure of the angle position feedback component is not an improvement point of this application and will not be described in detail here.

[0043] Example 2 Unlike Example 1, this example includes multiple ultrasonic probes 2, which are evenly arranged to form a circular array. For example, four ultrasonic probes can be evenly arranged around a central point to form an ultrasonic probe array, with each ultrasonic probe facing the semiconductor wafer. This achieves the effect of multiple ultrasonic probes in the ultrasonic probe array simultaneously scanning the sample under test along multiple circular trajectories of different diameters, which can save scanning time by several times compared to a single ultrasonic probe.

[0044] It should be noted that this imaging device is not limited to the structural designs of the aforementioned specific embodiments 1 and 2. Without departing from the principles of this application, those skilled in the art can make various equivalent substitutions or modifications to the specific structure and control flow of the imaging device. For example, the number and frequency of the ultrasonic probes 2 can be adjusted according to the detection requirements; the radial feed mechanism 3 can also adopt other types of linear drive components; the drive of the rotary platform 1 can be a direct drive motor to eliminate transmission errors, etc. These modifications should all be considered within the scope of protection of this invention.

[0045] In summary, those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

[0046] Example 3 This embodiment provides a method for imaging a sample under test using any of the acoustic microscope imaging devices provided in the foregoing embodiments, such as... Figure 3 As shown, the method includes the following steps: S1 control module 4 controls angle sensing unit 5 to collect rotation angle information of rotating platform 1; controls radial feed mechanism 3 to drive ultrasonic probe 2 to move along the radial direction of rotating platform 1 to the scanning start position according to preset step distance; Based on the rotation angle information, the control module 4 controls the rotating platform 1 to rotate the sample under test at a preset angular velocity until a circular trajectory is formed. During the rotation, the control module 4 controls the ultrasonic probe 2 to continuously scan and collect the echo signals at each position of the sample under test on the rotation trajectory until the circular trajectory is scanned and then the scanning stops. S3 repeats steps S1-S2 to obtain multiple echo signals on multiple circular trajectories, and uses all echo signals to generate a planar image of the sample under test.

[0047] Specifically, the radial feed mechanism 3 is controlled to move along the radial direction of the rotating platform 1, so as to drive the ultrasonic probe 2 to make a precise linear movement relative to the center of the sample to be tested.

[0048] The sample to be tested is mounted and fixed at the center of the rotating platform 1. The rotating platform 1 is driven to rotate at high speed around its central axis on the horizontal plane. At the same time, the ultrasonic probe 2 is controlled to emit high-frequency ultrasonic pulses to scan until the rotation forms a circular trajectory. The scanning trajectory of the ultrasonic probe 2 is also circular.

[0049] After completing one scan, the radial feed mechanism 3 moves sequentially along the radial direction of the rotating platform 1 according to the step distance, and obtains the next circular scanning trajectory in the aforementioned rotation and scanning manner, until the ultrasonic probe 2 moves from the center of the sample to its edge, gradually completing the scanning of the entire sample and obtaining multiple circular scanning trajectories. Specifically, the control module 4, based on the encoder position comparison result from the high-precision angle sensing unit 5, triggers the ultrasonic probe 2 to emit high-frequency ultrasonic pulses towards the sample. At the same time, the coupling medium spray module 21 sprays coupling medium from the ultrasonic transmitter end of the ultrasonic probe to form a fine and stable water flow, so as to stably transmit the high-frequency ultrasonic pulses to the interior of the sample and receive the echo signal reflected back from the internal interface of the sample. Since the ultrasonic probe 2 and the coupling medium spray module 21 are stationary during the scanning process, and only the rotating platform 1 is rotating, the current ultrasonic signal is more stable. Then, the encoder and linear encoder in the angle sensing unit 5 are used to obtain the rotation angle of the sample under test and the radial position of the ultrasonic probe 2 in real time. Each echo signal is associated with the corresponding polar coordinate position (radial distance r, angle θ) when the signal is generated, and the signals are collected and recorded synchronously.

[0050] The acquired ultrasonic echo signals are then converted from analog to digital and processed to extract the echo amplitude or phase information at the target depth as pixel grayscale values. An acoustic image is constructed in real-time in polar coordinates, using radial position and rotation angle as coordinates. For example, the sample is rotated one revolution, and the data along a circular trajectory obtained by the ultrasonic probe is used as one row of values ​​in the image (corresponding to a fixed radius r and different angles θ). New circular scan data are then continuously added as the ultrasonic probe 2 advances radially.

[0051] After obtaining the image data in polar coordinates, it is mapped to a planar image in rectangular coordinates using a coordinate transformation algorithm. Specifically, the corresponding rectangular coordinates (x, y) are calculated based on the radius r and angle θ, and interpolation compensation is performed on irregular pixel positions to generate a complete two-dimensional grayscale image corresponding to the actual sample plane. This process can be performed in real time by the control module 4 through a "scan conversion," which converts the polar coordinate image into a regular and intuitive rectangular coordinate image without distortion and displays it on a monitor.

[0052] More specifically, for each data point in the polar coordinate image, its corresponding position (x, y) in the Cartesian coordinate system is calculated based on its corresponding r and θ, with the relationship: x = r / cosθ, y = r / sinθ. Since the polar coordinate sampling has equal angular intervals in the θ direction, the spacing between the corresponding points on the Cartesian plane is uneven. Therefore, control module 4 can use an interpolation algorithm to map the discrete sampling points into a regular Cartesian coordinate pixel grid. For example, a lookup table can be established for the target Cartesian coordinate plane to map each target pixel back to polar coordinate space, and the grayscale value of the pixel can be calculated using bilinear interpolation. This real-time coordinate transformation process is efficiently implemented by computer software and performed synchronously throughout the scanning process, allowing the end user to directly see the gradually generated sample plane image in real time.

[0053] Furthermore, necessary post-processing can be performed on the generated image data, including noise reduction, contrast enhancement, pseudo-color rendering, and automatic defect identification. The control module 4 is equipped with ample data interfaces, supporting the introduction of advanced image processing algorithms to effectively reduce noise in acoustic images and improve the clarity of defect edges and textures. It can also automatically detect defect locations such as delamination, cracks, and cavities by running customized defect analysis software, achieving intelligent and rapid identification and improving detection efficiency. For example, using a deep learning-based image segmentation / classification model, it can identify regions with abnormal features in the image and provide a defect category determination. To improve the accuracy of defect detection, the control module 4 can also apply various post-processing algorithms to the image data during or after imaging to enhance the signal-to-noise ratio, such as using adaptive filtering to remove random noise or employing frequency domain analysis to eliminate periodic artifacts, thereby helping to improve the defect detection rate and location accuracy.

[0054] Using the above method, a complete scan of a 12-inch diameter wafer can be completed in less than 3 minutes, significantly improving detection efficiency. The scanning time using the imaging device in Example 2 is even shorter; for example, by setting four ultrasonic probes evenly distributed in a radial ring array to work in parallel, the entire wafer can be scanned and imaged in approximately 1 minute. The aforementioned imaging device avoids traditional large-area X and Y motion mechanisms, resulting in a compact structure, low maintenance, and significantly improved scanning efficiency and accuracy. Furthermore, the absence of large moving parts above the rotating platform reduces interference with the cleanroom environment.

[0055] It should be understood that the above-described device is used to execute the methods in the above embodiments. The implementation principle and technical effect of the corresponding program modules in the device are similar to those described in the above methods. The working process of the device can be referred to the corresponding process in the above methods, and will not be repeated here.

[0056] Based on the methods in the above embodiments, this application provides an electronic device, such as... Figure 4As shown, the electronic device may include a processor 510, a communications interface 520, a memory 530, and a communication bus 540, wherein the processor 510, the communications interface 520, and the memory 530 communicate with each other via the communication bus 540. The processor 510 can call logical instructions in the memory 530 to execute the methods in the above embodiments.

[0057] Furthermore, the logical instructions in the aforementioned memory 530 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0058] Based on the methods in the above embodiments, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0059] Based on the methods in the above embodiments, this application provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0060] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0061] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0062] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0063] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0064] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An acoustic microscope imaging device, characterized in that, The system includes a control module (4), a rotating platform (1), an ultrasonic probe (2), a radial feed mechanism (3), and an angle sensing unit (5) connected to the control module (4), wherein: the rotating platform (1) is used to carry the sample to be tested; the angle sensing unit (5) is set on the rotating platform (1) and is used to collect the rotation angle information of the rotating platform (1); the ultrasonic probe (2) is fixed on the radial feed mechanism (3) and is located directly above the sample to be tested; the control module (4) is used to control the radial feed mechanism (3) to drive the ultrasonic probe (2) to move multiple times along the radial direction of the rotating platform (1), and after each movement, control the rotating platform (1) to drive the sample to be tested to rotate to form a circular trajectory, and also to control the ultrasonic probe (2) to scan and collect the echo signal of the sample to be tested on the circular trajectory during the rotation process, and use all the echo signals on multiple circular trajectories to generate a planar image of the sample to be tested.

2. The acoustic microscope imaging device as described in claim 1, characterized in that, The ultrasonic probe (2) is provided with a coupling medium spraying module (21) for spraying coupling medium onto the sample to be tested during ultrasonic scanning, so as to form a liquid connection bridge between the ultrasonic probe (2) and the sample to be tested.

3. The acoustic microscope imaging device as described in claim 1, characterized in that, The ultrasonic probe (2) operates at a frequency of 15MHz to 500MHz.

4. The acoustic microscope imaging device as described in claim 1, characterized in that, The radial feed mechanism (3) includes a guide rail, a precision linear slide, and a servo motor drive unit. The guide rail is arranged radially above the rotary platform (1). The precision linear slide is mounted on the guide rail and can slide back and forth relative to the guide rail. The servo motor drive unit is connected to the precision linear slide and is used to provide sliding power for the precision linear slide.

5. An acoustic microscope imaging device as described in claim 1, characterized in that, The ultrasonic probe (2) is provided in multiple ways, and the multiple ultrasonic probes (2) are evenly arranged to form a circular array, and each ultrasonic probe (2) is facing the sample to be tested.

6. The acoustic microscope imaging device as described in claim 1, characterized in that, The radial feed mechanism (3) drives the ultrasonic probe (2) to move for a stroke that is not less than the radius of the sample to be tested.

7. An acoustic microscope imaging device as described in claim 1, characterized in that, The spacing between adjacent circular trajectories is equal.

8. An acoustic microscope imaging device as described in claim 1, characterized in that, The rotating platform (1) is equipped with a vacuum adsorption unit or a mechanical clamp, which is used to fix the sample to be tested.

9. An acoustic microscope imaging device as described in claim 1, characterized in that, The acquisition accuracy of the angle sensing unit (5) is less than ±5 arcseconds.

10. A method for imaging a sample under test using an acoustic microscope imaging device as described in any one of claims 1-9, characterized in that, include: S1 controls the angle sensing unit (5) to collect the rotation angle information of the rotating platform (1); controls the radial feed mechanism (3) to drive the ultrasonic probe (2) to move along the radial direction of the rotating platform (1) to the scanning start position according to the preset step distance; Based on the rotation angle information, S2 controls the rotating platform (1) to drive the sample to be tested to rotate at a preset angular velocity until a circular trajectory is formed. During the rotation, the ultrasonic probe (2) is controlled to continuously scan and collect the echo signals of each position of the sample to be tested on the circular trajectory until the circular trajectory is scanned and then the scanning stops. S3 repeats steps S1-S2 to obtain multiple echo signals on multiple circular trajectories, and uses all echo signals to generate a planar image of the sample under test.

Images