Particle deposition system, method, computer device and storage medium

Abstract

This invention provides a particle deposition system, method, computer equipment, and storage medium. The particle deposition system includes a control platform, a support platform, a container unit, a power unit, an electrostatic nozzle, and an electric field unit. The system proposed in this invention precisely controls the Bond number and micro-flow rate to form a stable cone-jet, achieving efficient atomization and directional deposition of a standard particle solution, through the coordinated operation of the control platform, power unit, electrostatic nozzle, and electric field unit. Furthermore, by linking the control platform with the support platform and / or the electrostatic nozzle, precise deposition at designated locations on the wafer surface is achieved. Ultimately, this significantly simplifies the system structure, reduces equipment and maintenance costs, and meets the high-precision, low-cost, and high-stability fabrication requirements of semiconductor front-end optical inspection equipment for particle standard wafers.

Description

Technical Field

[0001] This invention relates to the field of standard wafer manufacturing technology, and particularly to a particle deposition system, method, computer equipment, and storage medium. Background Technology

[0002] Semiconductor chip manufacturing is a complex process, divided into front-end, mid-end, and back-end processes. In the front-end process, defect detection equipment requires the use of particle standard wafers to calibrate the relationship between particle size and optical detection signals, thereby calculating the size of the contaminating particles being detected. As semiconductor chip manufacturing processes advance to the nanometer scale, the requirements for controlling particle contamination on wafer surfaces have increased significantly. Optical-based detection methods have become mainstream in the industry due to their high efficiency, speed, and accuracy. Particle deposition systems are the core equipment for preparing particle standard wafers, and their performance directly affects detection accuracy and cost.

[0003] Currently, the mainstream particle deposition equipment is the particle deposition system developed by MSP Corporation in the United States. The core deposition process of this system consists of four steps:

[0004] 1. Atomization and drying: The liquid suspension containing standard particles is atomized and dried to form solid particle aerosols; 2. Size sorting: Charged particles of specific sizes are screened using a differential electromobility analyzer to obtain a uniform particle flow. 3. Quantity control: The particle concentration is monitored and adjusted in real time using a condensation nucleus particle counter to achieve quantitative control of the total number of deposited particles. IV. Electrophoretic deposition: Particles are attracted and fixed to a designated position on the wafer surface by an electrostatic field.

[0005] However, the aforementioned particle deposition system has significant drawbacks: First, its structure is extremely complex, integrating multiple precision subsystems such as aerosol generation and drying, and differential electromobility sorting, making operation and maintenance difficult; second, the system is expensive, with high initial investment and subsequent maintenance costs, resulting in high production costs for particle standard wafers; and third, its dynamic range is limited, with particle sorting constrained by the chamber length of the differential electromobility analyzer, requiring equipment replacement or complex splicing for analyzing wider particle size spectra, thus limiting its applicability and making it difficult to meet the needs of the rapidly developing semiconductor industry.

[0006] Therefore, it is necessary to propose a new particle deposition system to solve the above problems. Summary of the Invention

[0007] This invention provides a particle deposition system, method, computer device, and storage medium, aiming to solve the technical problems of complex structure and limited function of existing particle deposition systems.

[0008] To address the aforementioned technical problems, in a first aspect, the present invention provides a particle deposition system, comprising a control platform, a support platform, a container unit, a power unit, an electrostatic nozzle, an electric field unit, an image acquisition unit, and an illumination unit, wherein: The control platform is electrically connected to the support platform, the power unit, the electrostatic nozzle, and the electric field unit, respectively, and is used to control the working status of other platforms and units in the particle deposition system. The support platform is used to support the wafer to be deposited with particles, and the wafer is grounded via the support platform; wherein, the support platform can drive the wafer to move relative to the electrostatic nozzle under the control of the control platform; The container unit is used to hold the standard particle solution, which is a solution formed by dispersing standard particles in a volatile solvent; The power unit is connected to the container unit and the electrostatic nozzle respectively, and is used to extract the standard particle solution from the container unit under the control of the control platform, and push the standard particle solution to the electrostatic nozzle according to a preset solution flow rate; The electrostatic nozzle is located directly above the support platform and is used to receive the standard particle solution, spray the standard particle solution and atomize it into a cone-jet spray that encapsulates the standard particles, so that the spray is deposited on the surface of the wafer; wherein, the electrostatic nozzle can move relative to the wafer under the control of the control platform; The electric field unit is used to provide the electrostatic nozzle with the electric field required for the spray to form a cone-jet under the control of the control platform.

[0009] Furthermore, the electric Bond number of the electric field provided by the electric field unit is defined as follows: It meets the following conditions: ; in, ε The dielectric constant of the standard particle solution is given. σ The surface tension of the standard particle solution is... R The inner radius of the electrostatic nozzle is [missing information]. E Let be the electric field strength of the electric field.

[0010] Furthermore, the minimum preset solution flow rate is defined as the value at which the power unit pushes the standard particle solution to the electrostatic nozzle. It meets the following conditions: ; in, The vacuum permittivity, The liquid density of the standard particle solution is given. The conductivity of the standard particle solution is given.

[0011] Furthermore, the particle deposition system also includes a particle detection microfluidic unit, which is disposed between the container unit and the power unit and is connected to both the container unit and the power unit. The particle detection microfluidic unit is electrically connected to the control unit. The particle detection microfluidic unit integrates detection micropores with positive and negative electrodes, which are used to detect the particle size and count particles in the standard particle solution through pulse signals when the standard particle solution flows through the detection micropores, thereby obtaining the detection results. The control platform is also used to: adjust the solution flow rate of the power unit or the deposition time of the electrostatic nozzle in real time according to the detection result; when the deviation between the detection result and the preset particle target value is greater than the preset threshold, control the power unit to stop working and issue an alarm signal.

[0012] Furthermore, the particle deposition system also includes a particle screening microfluidic unit, which is disposed between the particle detection microfluidic unit and the power unit, and is connected to both the particle detection microfluidic unit and the power unit. The particle screening microfluidic unit is electrically connected to the control unit. The particle screening microfluidic unit integrates a submicron-level flow channel, which is used to sort the standard particles by dielectrophoresis when the standard particle solution flows through the submicron-level flow channel, so as to obtain and output a particle flow that meets a preset particle size threshold.

[0013] Furthermore, the particle deposition system also includes an image acquisition unit and an illumination unit, wherein: The image acquisition unit is electrically connected to the control unit and is used to acquire real-time images of the spray status under the control of the control platform. The lighting unit is used to provide a light source for illuminating the image acquisition unit; The control platform is also used for: Based on the status image, determine whether the spray is abnormal. If so, control the power unit to stop working and issue an alarm signal.

[0014] Furthermore, the standard particles are silicon dioxide or polystyrene, with a particle diameter between 10 nanometers and 3 micrometers; The volatile solvent is anhydrous ethanol or isopropanol with a purity greater than 99.5%; Under the control of the control platform, the carrier platform and / or the electrostatic nozzle make the preset distance between the surface of the wafer and the nozzle tip of the electrostatic nozzle between 40 mm and 60 mm.

[0015] Secondly, the present invention also provides a particle deposition method, which is implemented by the particle deposition system described above and controlled by the control platform. The particle deposition method includes the following steps: Drive the carrier platform and / or the electrostatic nozzle to move, so that the distance between the nozzle tip of the electrostatic nozzle and the surface of the wafer is maintained within a preset distance; The power unit is controlled to draw standard particle solution from the container unit and push it to the electrostatic nozzle at a preset solution flow rate; The output voltage of the electric field unit is adjusted to form the electric field required for the spray to form a cone-jet within the spray area of ​​the electrostatic nozzle; The electrostatic nozzle is controlled to spray out the standard particle solution and atomize it into a spray that encapsulates the standard particles, so that the spray is deposited on the wafer surface under the action of the electric field; Drive the carrier platform and / or the electrostatic nozzle to adjust the relative position of the electrostatic nozzle and the wafer until particle deposition at a specified position on the wafer surface is completed.

[0016] Thirdly, the present invention also provides a computer device, comprising: a memory, a processor, and a particle deposition program stored in the memory and executable on the processor, wherein the processor executes the particle deposition program to implement the steps of the particle deposition method as described in the above embodiments.

[0017] Fourthly, the present invention also provides a storage medium storing a particle deposition program, which, when executed by a processor, implements the steps of the particle deposition method as described in the above embodiments.

[0018] The beneficial effects achieved by this invention lie in proposing a wafer particle deposition system based on electrostatic spraying. This system, through the coordinated operation of a control platform, a power unit, an electrostatic nozzle, and an electric field unit, precisely regulates the electric Bond number and micro-flow rate to form a stable cone-jet, achieving efficient atomization and directional deposition of standard particle solutions. Furthermore, by linking the control platform with the support platform and / or the electrostatic nozzle, precise deposition at designated locations on the wafer surface is achieved. Ultimately, this significantly simplifies the system structure, reduces equipment and maintenance costs, and meets the high-precision, low-cost, and high-stability fabrication requirements of semiconductor front-end optical inspection equipment for particle standard wafers. Attached Figure Description

[0019] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and more readily understood through the detailed description following the accompanying drawings. In the drawings: Figure 1This is a schematic diagram of the particle deposition system provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the spraying of the particle deposition system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of particle deposition in the particle deposition system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of another particle deposition system provided in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of another particle deposition system provided in Embodiment 3 of the present invention; Figure 6 This is a flowchart of the particle deposition method provided in the embodiments of the present invention; Figure 7 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0020] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0021] The specific embodiments / examples described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation methods or scope of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein, all of which are within the protection scope of the present invention.

[0022] Example 1 Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a particle deposition system 100 provided in an embodiment of the present invention. The particle deposition system 100 includes a control platform 1, a support platform 2, a container unit 3, a power unit 4, an electrostatic nozzle 5, and an electric field unit 6, wherein: The control platform 1 is electrically connected to the support platform 2, the power unit 4, the electrostatic nozzle 5 and the electric field unit 6 respectively, and is used to perform overall control of other platforms and units in the particle deposition system 100; The support platform 2 is used to support the wafer to be deposited with particles, and the wafer is grounded via the support platform 2; wherein, the support platform 2 can drive the wafer to move relative to the electrostatic nozzle 5 under the control of the control platform 1; The container unit 3 is used to hold the standard particle solution, which is a solution formed by dispersing standard particles in a volatile solvent; The power unit 4 is connected to the container unit 3 and the electrostatic nozzle 5 respectively, and is used to extract the standard particle solution from the container unit 3 under the control of the control platform 1, and push the standard particle solution to the electrostatic nozzle 5 according to the preset solution flow rate; The electrostatic nozzle 5 is located directly above the support platform 2 and is used to receive the standard particle solution, spray the standard particle solution and atomize it into a cone-jet spray that encapsulates the standard particles, so that the spray is deposited on the surface of the wafer; wherein, the electrostatic nozzle 5 can move relative to the wafer under the control of the control platform 1; The electric field unit 6 is used to provide the electrostatic nozzle 5 with the electric field required for the spray to form a cone-jet under the control of the control platform 1.

[0023] In this embodiment of the invention, the control platform 1 serves as an overall control unit and is electrically connected to the bearing platform 2, the power unit 4, the electrostatic nozzle 5, and the electric field unit 6, including physical electrical connection and communication connection. The control platform 1 can be implemented by a host computer device (such as a computer or controller) and can receive external control commands and transmit them to the corresponding platform or unit.

[0024] The carrier platform 2, as a carrier stage for the wafer, adopts a replaceable disk structure, and the size of the disk corresponds to the size of the wafer to be carried. The carrier platform 2 is connected to a drive component that can move along three axes: X-axis, Y-axis, and Z-axis, and has a rotating shaft (R-axis) at its end. The end of the drive component is fixedly connected to the center of the disk of the carrier platform 2. Under the control of the control platform 1, the drive component drives the carrier platform 2 to move along the axial direction or to rotate circumferentially around the axial direction of the center of the disk, thereby driving the wafer to synchronously complete linear movement and rotation, and realizing the position adjustment of the wafer relative to the electrostatic nozzle 5.

[0025] Container unit 3 is preferably made of glass, which is required to have good sealing properties, corrosion resistance, and not react with the standard particle solution it contains.

[0026] The power unit 4 is a pump-type device. Its inlet is connected to the container unit 2 through a conduit, and its outlet is connected to the electrostatic nozzle 5 through a short circuit. In the scenario of this embodiment, the power unit 4 needs to achieve a solution extraction performance of microliters per minute.

[0027] The electrostatic nozzle 5 is a micro-jet component with a precision flow channel, and is a key actuator for electrostatic spray deposition. It is preferably made of metal or ceramic, with an inner diameter of less than 100 micrometers, and is smooth and burr-free to avoid burrs affecting the electric field distribution. In this embodiment, the electrostatic nozzle 5, in conjunction with the electric field unit 6, forms a directional electric field that rapidly stretches and breaks up the standard particle solution flowing through the nozzle 5, forming a stable cone-jet that atomizes into nano-sized droplets (each droplet contains at least one standard particle). The droplets, encapsulating the standard particles, are precisely directed towards the wafer surface under the influence of the electric field. Combined with the rapid evaporation of volatile solvents and the continuous movement of the wafer by the support platform 2 during spraying to adjust the deposition area, a uniform, monodisperse standard particle is ultimately left on the wafer. Similar to the support platform 2, the electrostatic nozzle 5 is also connected to a drive assembly that can move along three axes and has a rotatable end. This drive assembly, under the control of the control platform 1, moves the electrostatic nozzle 5 relative to the wafer. Under possible control logic, the movement of the carrier platform 2 and the electrostatic nozzle 5 can be carried out simultaneously or separately. The ultimate goal of the control is to make the electrostatic nozzle 5 continuously adjust its relative position with the wafer, thereby achieving the deposition of all particles in a specific area of ​​the wafer.

[0028] Electric field unit 6 is a high-voltage DC power supply module. Its output terminal is electrically connected to the electrostatic nozzle 5, and its reference terminal is electrically connected to the carrier platform 2 that carries the wafer and grounded.

[0029] Specifically, the electric Bond number is a core parameter characterizing the balance between the electric field force and the surface tension of the solution during electrostatic spraying. It directly determines whether the electrostatic nozzle 5 can form a stable cone-jet, and is key to achieving efficient and uniform atomization. The electric Bond number of the electric field provided by the electric field unit 6 is defined as... It meets the following conditions: ; in, ε Where is the dielectric constant. σ The surface tension of the standard particle solution is... R The inner radius of the electrostatic nozzle 5 is [missing information]. E Let be the electric field strength of the electric field.

[0030] In this embodiment of the invention, the output electric field strength of the electric field unit 6 is adjusted to strictly control the electric Bond number within the range of 1 to 10: when the electric Bond number is less than 1, the electric field driving force is insufficient and cannot overcome the surface tension of the solution to form a cone-jet, resulting in only ordinary droplets falling; when the electric Bond number is greater than 10, the electric field force is too strong, the jet is unstable and the droplets splash, and it is impossible to form a spray that uniformly encapsulates the standard particles.

[0031] Stable cone-jet spray such as Figure 2As shown in 'a', this indicates that the electric field strength at this time meets the conditions described in the above embodiments, and Figure 2 b in the figure illustrates the jet instability when the electric field force is too strong; Figure 3 This is a distribution diagram of particles deposited on the wafer surface by a stable cone-jet spray. Therefore, ensuring that the electric Bond number of the electric field provided by electric field unit 6 is within the parameter range can ensure a dynamic balance between the electric field and surface tension, continuously generating a stable cone-jet and guaranteeing consistent particle deposition. Grounding the wafer via the support platform 2 is also to ensure the stability of the electrostatic field.

[0032] The minimum value of the preset solution flow rate when the power unit 4 pushes the standard particle solution to the electrostatic nozzle 5 is defined as follows: It meets the following conditions: ; in, The vacuum permittivity, The liquid density of the standard particle solution is given. The conductivity of the standard particle solution is given.

[0033] This is the minimum solution flow rate threshold required to maintain a stable cone-jet electrostatic spray, determined by the physicochemical properties of the standard particle solution and the electric field conditions. This flow rate threshold reflects the constraints imposed on atomization stability by solution surface tension, vacuum dielectric constant, liquid density, and conductivity. The actual operating flow rate must be matched to this threshold in conjunction with the electric field strength: the higher the electric field strength, the greater the required flow rate; insufficient flow rate will lead to cone-jet breakage and atomization interruption. Through... The flow rate of the power unit 4 is precisely set based on the benchmark, which can ensure a continuous and stable supply of solution. Combined with electric field control, it can achieve continuous and uniform standard particle spray deposition.

[0034] Specifically, in this embodiment of the invention, the particle deposition system 100 further includes an image acquisition unit 7 and an illumination unit 8, wherein: The image acquisition unit 7 is electrically connected to the control unit 1 and is used to acquire real-time images of the spray status under the control of the control platform 1. The lighting unit 8 is used to provide a light source for illuminating the image acquisition unit 7; The control platform 1 is also used for: Based on the status image, determine whether the spray is abnormal. If so, control the power unit 4 to stop working and issue an alarm signal.

[0035] The image acquisition unit 7 is a high-precision vision acquisition component. It can use an industrial camera or a high-definition video camera. Under the control of the control platform 1, it is aimed at the spray area of ​​the electrostatic nozzle 5, and high-definition status images of the cone-jet spray are acquired in real time and uploaded to the control platform 1. The lighting unit 8 is a light source component used to provide auxiliary lighting for the spray area of ​​the electrostatic nozzle. It can use an LED device and works under the control of the control platform 1. It can output parallel lighting light with uniform brightness and no obvious glare or shadows, thereby eliminating ambient light interference. This allows the image acquisition unit 7 to clearly capture the shape of the cone-jet spray at the electrostatic nozzle 5, providing good visual conditions for image recognition and anomaly judgment of the spray state.

[0036] In this embodiment of the invention, a real-time visual monitoring closed loop is constructed through the illumination unit 8 and the image acquisition unit 7. The control platform 1 performs online recognition and analysis of the spray status images, which can accurately identify abnormal conditions such as cone-jet instability, droplet splashing, and spray interruption. Once an abnormality is detected, the control platform 1 immediately cuts off the liquid supply from the power unit 4 and triggers an alarm, avoiding uneven particle deposition, positional displacement, or wafer contamination caused by spray abnormalities. This effectively improves the stability and yield of the particle deposition process and ensures that the prepared standard wafers meet the accuracy requirements of semiconductor optical inspection.

[0037] In this embodiment of the invention, the standard particles in the standard particle solution are silicon dioxide or polystyrene, with a particle diameter between 10 nanometers and 3 micrometers; The volatile solvent is anhydrous ethanol or isopropanol with a purity greater than 99.5%.

[0038] This invention selects silicon dioxide (SiO2) or polystyrene (PSL) as standard particles. Both are commonly used spherical standard particles in the field of semiconductor particle detection, exhibiting excellent particle size uniformity and physicochemical stability. The particle size covers the range of 10 nanometers to 3 micrometers, meeting the full-range calibration requirements for current nanoscale processes to micrometer-level contamination detection. Anhydrous ethanol or isopropanol with a purity greater than 99.5% is used as the dispersion solvent. These solvents are highly volatile and have extremely low residue, allowing for rapid and complete evaporation after deposition, preventing the introduction of impurities and contaminants onto the wafer surface, and strictly meeting the ultra-high cleanliness requirements of semiconductor front-end processes.

[0039] Under the control of the control platform 1, the carrier platform 2 and / or the electrostatic nozzle 5 are such that the preset distance between the surface of the wafer and the nozzle tip of the electrostatic nozzle 5 (i.e. the port from which the standard particle solution is ejected by the electrostatic nozzle 5) is between 40 mm and 60 mm.

[0040] In this embodiment of the invention, the distance between the tip of the electrostatic nozzle 5 and the wafer surface is controlled to be 40 mm to 60 mm, which is the optimal working distance for electrostatic spray deposition. Too small a distance can easily lead to electric field breakdown, nozzle contamination, or particle rebound; too large a distance will cause the electric field strength to decrease, reducing the droplet deposition positioning accuracy. By precisely maintaining the distance through the support platform 2 and / or the electrostatic nozzle 5, a uniform electrostatic field distribution and stable particle force can be ensured, allowing standard particles to be accurately deposited at the designated position on the wafer, significantly improving the deposition position accuracy and particle distribution uniformity.

[0041] Example 2 This invention also provides another particle deposition system 200, which, compared to the unit components described in Embodiment 1, such as... Figure 4 As shown, the particle deposition system 200 further includes a particle detection microfluidic unit 9, which is disposed between the container unit 3 and the power unit 4 and is connected to both the container unit 3 and the power unit 4. The particle detection microfluidic unit 9 is electrically connected to the control unit 1. The particle detection microfluidic unit 9 integrates detection micropores with positive and negative electrodes, which are used to detect the particle size and count particles of the standard particle solution through pulse signals when the standard particle solution flows through the detection micropores, so as to obtain the detection results. The control platform 1 is also used to: adjust the solution flow rate of the power unit 4 or the deposition time of the electrostatic nozzle 5 in real time according to the detection result; when the deviation between the detection result and the preset particle target value is greater than the preset threshold, control the power unit 4 to stop working and issue an alarm signal.

[0042] Specifically, another particle deposition system 200 provided in this embodiment of the invention adds a particle detection microfluidic unit 9 to the first embodiment, which can further improve the quantitative accuracy and process reliability of particle deposition through online detection and closed-loop control.

[0043] The particle detection microfluidic unit 9 integrates detection micropores with positive and negative electrodes. The micropore size can be flexibly matched according to the standard particle size. The ratio of the standard particle size to the detection micropore size is usually controlled between 2% and 40% to ensure detection sensitivity and accuracy. The particle detection microfluidic unit 9 also supports a multi-channel impedance detection architecture. Different micropore chips with different pore sizes can be switched through a reversing valve to adapt to the precise detection of standard particles with a wide particle size range from 10 nanometers to several micrometers.

[0044] When the standard particle solution flows through the detection micropore, the particles will block the current between the electrodes and generate characteristic pulse signals. The system analyzes the amplitude and number of pulse signals to simultaneously complete particle size verification and real-time counting, and outputs stable and reliable detection results.

[0045] Based on the detection results, the control platform 1 constructs a closed-loop control logic, compares the actual particle count with the preset target value in real time, and dynamically adjusts the flow rate of the power unit 4 at the microliter per minute level or the deposition time of the electrostatic nozzle 5 to ensure that the number of deposited particles accurately matches the calibration requirements. If the deviation between the detection result and the preset particle target value exceeds the preset threshold, it is determined that there are problems such as abnormal particle concentration, mismatched particle size, or pipeline blockage. The control platform 1 immediately controls the power unit 4 to stop the liquid supply and issues an alarm signal to avoid producing unqualified particle standard wafers, thereby significantly improving the deposition yield and the reliability of semiconductor optical detection calibration.

[0046] Example 3 This invention also provides another particle deposition system 300, which, compared to the unit components described in Embodiment 2, such as... Figure 5 As shown, the particle deposition system 300 further includes a particle screening microfluidic unit 10, which is disposed between the particle detection microfluidic unit 9 and the power unit 4, and is connected to both the particle detection microfluidic unit 9 and the power unit 4. The particle screening microfluidic unit 10 is electrically connected to the control unit 1. The particle screening microfluidic unit 10 integrates a submicron-level flow channel, which is used to sort the standard particles by dielectrophoresis when the standard particle solution flows through the submicron-level flow channel, so as to obtain and output a particle flow that meets a preset particle size threshold.

[0047] Another particle deposition system 300 provided in this embodiment of the invention further adds a particle screening microfluidic unit 10 based on embodiment two. Through precise pre-particle size sorting, the size uniformity of standard particles is significantly improved, meeting the requirements for higher precision particle standard wafer preparation. The particle screening microfluidic unit 10 is located between the particle detection microfluidic unit 9 and the liquid inlet of the power unit 4, so that the standard particle solution is detected before entering the sorting stage, resulting in a smooth fluid path and efficient unit collaboration.

[0048] The particle screening microfluidic unit 10 integrates submicron-level precision flow channels, achieving efficient particle size sorting of standard particles based on the dielectric effect: particles of different sizes experience significantly different dielectric forces within the flow channel; larger-diameter particles experience greater dielectric forces and deflect at larger angles, while smaller-diameter particles experience less dielectric forces and deflect at smaller angles. This difference in forces allows for effective separation of particles of different sizes. The system can also employ a cascaded approach with multiple sorting microfluidic chips for finer particle size classification, thoroughly removing out-of-diameter impurities and oversized particles. The final output is a stream of target particles with a narrow particle size distribution and high uniformity, ensuring consistent particle size of standard particles deposited on the wafer surface from the source. This significantly improves the calibration accuracy and stability of the particle standard wafer, better meeting the optical inspection and calibration requirements of nanoscale semiconductor processes.

[0049] The beneficial effects achieved by this invention lie in proposing a wafer particle deposition system based on electrostatic spraying. This system, through the coordinated operation of a control platform, a power unit, an electrostatic nozzle, and an electric field unit, precisely regulates the electric Bond number and micro-flow rate to form a stable cone-jet, achieving efficient atomization and directional deposition of standard particle solutions. Furthermore, by linking the control platform with the support platform and / or the electrostatic nozzle, precise deposition at designated locations on the wafer surface is achieved. Ultimately, this significantly simplifies the system structure, reduces equipment and maintenance costs, and meets the high-precision, low-cost, and high-stability fabrication requirements of semiconductor front-end optical inspection equipment for particle standard wafers.

[0050] Example 4 This invention also provides a particle deposition method, please refer to... Figure 6 , Figure 6 This is a flowchart of the particle deposition method provided in this embodiment of the invention. The particle deposition method is implemented by the control platform in the particle deposition system described in the above embodiment, and includes the following steps: S1. Drive the carrier platform and / or the electrostatic nozzle to move, so that the distance between the nozzle tip of the electrostatic nozzle and the surface of the wafer is maintained within a preset distance.

[0051] S2. Control the power unit to extract standard particle solution from the container unit and push it to the electrostatic nozzle at a preset solution flow rate.

[0052] S3. Adjust the output voltage of the electric field unit to form the electric field required for the spray to form a cone-jet within the spray area of ​​the electrostatic nozzle.

[0053] S4. Control the electrostatic nozzle to spray out the standard particle solution and atomize it into a spray that encapsulates the standard particles, so that the spray is deposited on the wafer surface under the action of the electric field.

[0054] S5. Drive the carrier platform and / or the electrostatic nozzle to move, so as to adjust the relative position of the electrostatic nozzle and the wafer until the particle deposition at the specified position on the wafer surface is completed.

[0055] The particle deposition method described in this invention uses a control platform as the core execution entity, and coordinates various units of the system to complete the entire process of automated and precise deposition, ensuring spray stability and accurate positioning throughout the process.

[0056] Specifically, in the implementation process, step S1 controls the platform to drive the carrier platform and / or the electrostatic nozzle to adjust the wafer position, stabilizing the distance between the nozzle and the wafer in the optimal range of 40mm to 60mm, so as to ensure uniform electric field distribution. Step S2 involves the power unit drawing the solution at a micro-liter per minute flow rate to ensure a stable and precise solution supply. Step S3 adjusts the output of the electric field unit to a kilovolt-level high voltage, maintaining the electric Bond number between 1 and 10 to meet the conditions for stable cone-jet formation; Step S4 involves controlling an electrostatic nozzle to atomize the solution into tiny droplets encapsulating standard particles, which then undergo directional deposition under the influence of an electrostatic field, allowing volatile solvents to evaporate rapidly without residue. Step S5 continuously adjusts the position of the spray on the wafer by axial or rotational movement of the support platform and / or electrostatic nozzle, thereby achieving particle deposition at any specified position on the wafer surface, which is highly efficient, stable and accurately positioned throughout the process.

[0057] The particle deposition method is implemented based on the particle deposition system 100 as described in Embodiment 1 above, and can achieve the same technical effect. Referring to the description in the above embodiments, it will not be repeated here.

[0058] Example 5 This invention also provides a computer device, please refer to... Figure 7 , Figure 7 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present invention. The computer device 400 includes: a memory 402, a processor 401, and a particle deposition program stored in the memory 402 and executable on the processor 401.

[0059] The processor 401 calls the particle deposition program stored in the memory 402 and executes the steps in the particle deposition method provided in this embodiment of the invention. Please refer to... Figure 6 The particle deposition method is implemented by the control platform in the particle deposition system described in the above embodiment, and the particle deposition method includes the following steps: S1. Drive the carrier platform and / or the electrostatic nozzle to move, so that the distance between the nozzle tip of the electrostatic nozzle and the surface of the wafer is maintained within a preset distance.

[0060] S2. Control the power unit to extract standard particle solution from the container unit and push it to the electrostatic nozzle at a preset solution flow rate.

[0061] S3. Adjust the output voltage of the electric field unit to form the electric field required for the spray to form a cone-jet within the spray area of ​​the electrostatic nozzle.

[0062] S4. Control the electrostatic nozzle to spray out the standard particle solution and atomize it into a spray that encapsulates the standard particles, so that the spray is deposited on the wafer surface under the action of the electric field.

[0063] S5. Drive the carrier platform and / or the electrostatic nozzle to move, so as to adjust the relative position of the electrostatic nozzle and the wafer until the particle deposition at the specified position on the wafer surface is completed.

[0064] The computer device 400 provided in this embodiment of the invention can implement the steps in the particle deposition method as described in the above embodiments and can achieve the same technical effect. Referring to the description in the above embodiments, it will not be repeated here.

[0065] Example 6 This invention also provides a storage medium storing a particle deposition program. When the particle deposition program is executed by a processor, it implements the various processes and steps in the particle deposition method provided in this invention and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0066] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by hardware related to particle deposition programs or instructions. The programs can be stored in a computer-readable storage medium, and when executed, they can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0067] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0068] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0069] The embodiments of the present invention have been described above with reference to the accompanying drawings. The disclosed embodiments are merely preferred embodiments of the present invention. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many equivalent changes in form under the guidance of the present invention without departing from the spirit and scope of the claims, and all such changes are within the protection scope of the present invention.

Claims

1. A particle deposition system, characterized by, The particle deposition system includes a control platform, a support platform, a container unit, a power unit, an electrostatic nozzle, and an electric field unit, wherein: The control platform is electrically connected to the support platform, the power unit, the electrostatic nozzle, and the electric field unit, respectively, and is used to control the working status of other platforms and units in the particle deposition system. The support platform is used to support the wafer to be deposited with particles, and the wafer is grounded via the support platform; wherein, the support platform can drive the wafer to move relative to the electrostatic nozzle under the control of the control platform; The container unit is used to hold the standard particle solution, which is a solution formed by dispersing standard particles in a volatile solvent; The power unit is connected to the container unit and the electrostatic nozzle respectively, and is used to extract the standard particle solution from the container unit under the control of the control platform, and push the standard particle solution to the electrostatic nozzle according to a preset solution flow rate; The electrostatic nozzle is located directly above the support platform and is used to receive the standard particle solution, spray the standard particle solution and atomize it into a cone-jet spray that encapsulates the standard particles, so that the spray is deposited on the surface of the wafer; wherein, the electrostatic nozzle can move relative to the wafer under the control of the control platform; The electric field unit is used to provide the electrostatic nozzle with the electric field required for the spray to form a cone-jet under the control of the control platform.

2. The particle deposition system according to claim 1, characterized in that, The electric Bond number of the electric field provided by the electric field unit is defined as follows: It meets the following conditions: ； in, ε The dielectric constant of the standard particle solution is given. σ The surface tension of the standard particle solution is... R The inner radius of the electrostatic nozzle is [missing information]. E Let be the electric field strength of the electric field.

3. The particle deposition system according to claim 2, characterized in that, The minimum preset solution flow rate is defined as the value at which the power unit pushes the standard particle solution to the electrostatic nozzle. It meets the following conditions: ； in, The vacuum permittivity, The liquid density of the standard particle solution is given. The conductivity of the standard particle solution is given.

4. The particle deposition system according to claim 1, characterized in that, The particle deposition system further includes a particle detection microfluidic unit, which is disposed between the container unit and the power unit and is connected to both the container unit and the power unit. The particle detection microfluidic unit is electrically connected to the control unit. The particle detection microfluidic unit integrates detection micropores with positive and negative electrodes, which are used to detect the particle size and count particles of the standard particle solution through pulse signals when the standard particle solution flows through the detection micropores, so as to obtain the detection results. The control platform is also used to: adjust the solution flow rate of the power unit or the deposition time of the electrostatic nozzle in real time according to the detection result; when the deviation between the detection result and the preset particle target value is greater than the preset threshold, control the power unit to stop working and issue an alarm signal.

5. The particle deposition system according to claim 4, characterized in that, The particle deposition system further includes a particle screening microfluidic unit, which is disposed between the particle detection microfluidic unit and the power unit, and is connected to both the particle detection microfluidic unit and the power unit. The particle screening microfluidic unit is electrically connected to the control unit. The particle screening microfluidic unit integrates a submicron-level flow channel, which is used to sort the standard particles by dielectrophoresis when the standard particle solution flows through the submicron-level flow channel, so as to obtain and output a particle flow that meets a preset particle size threshold.

6. The particle deposition system according to claim 1, characterized in that, The particle deposition system further includes an image acquisition unit and an illumination unit, wherein: The image acquisition unit is electrically connected to the control unit and is used to acquire real-time images of the spray status under the control of the control platform. The lighting unit is used to provide a light source for illuminating the image acquisition unit; The control platform is also used for: Based on the status image, determine whether the spray is abnormal. If so, control the power unit to stop working and issue an alarm signal.

7. The particle deposition system according to claim 1, characterized in that, The standard particles in the standard particle solution are silicon dioxide or polystyrene, with a particle diameter between 10 nanometers and 3 micrometers. The volatile solvent is anhydrous ethanol or isopropanol with a purity greater than 99.5%; Under the control of the control platform, the carrier platform and / or the electrostatic nozzle make the preset distance between the surface of the wafer and the nozzle tip of the electrostatic nozzle between 40 mm and 60 mm.

8. A particle deposition method, characterized in that, The particle deposition method is implemented based on the particle deposition system according to any one of claims 1 to 7, and is controlled by the control platform. The particle deposition method includes the following steps: Drive the carrier platform and / or the electrostatic nozzle to move, so that the distance between the nozzle tip of the electrostatic nozzle and the surface of the wafer is maintained within a preset distance; The power unit is controlled to draw standard particle solution from the container unit and push it to the electrostatic nozzle at a preset solution flow rate; The output voltage of the electric field unit is adjusted to form the electric field required for the spray to form a cone-jet within the spray area of ​​the electrostatic nozzle; The electrostatic nozzle is controlled to spray out the standard particle solution and atomize it into a spray that encapsulates the standard particles, so that the spray is deposited on the wafer surface under the action of the electric field; Drive the carrier platform and / or the electrostatic nozzle to adjust the relative position of the electrostatic nozzle and the wafer until particle deposition at a specified position on the wafer surface is completed.

9. A computer device, characterized in that, include: The processor includes a memory, a processor, and a particle deposition program stored in the memory and executable on the processor, wherein the processor, when executing the particle deposition program, implements the steps of the particle deposition method as described in claim 8.

10. A storage medium, characterized in that, The storage medium stores a particle deposition program, which, when executed by a processor, implements the steps of the particle deposition method as described in claim 8.

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