# Numerical Simulation-Based Study of Controlled Particle Deposition Technology for Wafer Surfaces
## 4 Conclusions  
In this study, by generating monodisperse aerosols, numerically simulating the particle deposition chamber, and establishing the generation-deposition system, four SW samples meeting the SSIS calibration requirements were successfully prepared with particle sizes ranging from 70 to 200 nm. The main conclusions drawn from the experiment are as follows:  
1. Fluent simulations identified the optimal parameters for area deposition as a 4 mm nozzle diameter, 15 mm nozzle-to-wafer distance, deposition chamber volume greater than 657 cm\({}^{3}\), and a rotation speed of 0.314 rad/s. Under these conditions, uniform deposition can be achieved with a spot diameter of 23.7 mm and a deposition efficiency of 33.1%. Particles \(\geq\)100 nm can be stably deposited under standardized  
Figure 12: Comparison of deposition efficiency between simulation and experiment.  
parameters, whereas particles <100 nm require adjustments to other parameters to improve deposition efficiency.
2. SEM analysis confirmed that the standard PSL suspension used in the experiment aligns with the nominal particle size, making it a suitable raw material for monodisperse aerosol generation. Although multiple particle size peaks were observed in the SMPS scan spectrum, the number concentration at the main peak corresponding to the target particle size was significantly higher than that of the other peaks. Analysis of this phenomenon indicates that SMPS scanning data can serve as a reliable basis for particle size distribution measurement.
3. System validation based on simulation results successfully produced four SW samples (70-200 nm). Experimental results confirmed that the deposition efficiency reached 28% for all samples except the 70 nm sample. SSIS testing further verified that these samples meet the requirements for SSIS calibration.  
Conceptualization, J.R. and J.L.; methodology, J.L., Y.L. and Z.Z.; software, Z.Z.; validation, J.R., J.L., Y.L. and Z.Z.; investigation, J.L., Y.L. and Z.Z.; writing--original draft preparation, Z.Z. and J.L.; writing--review and editing, J.R., J.L. and Z.Z.; visualization, Z.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Special Project for Quality and Technical Basic Capability Construction of the State Administration for Market Regulation (grant number ANL2508), and Key areas of basic scientific research business expenses of the National Institute of Metrology China (grant number AKYZD2308-1).  
Not applicable.  
The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author.  
We gratefully acknowledge the administrative and technical support provided by the State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, which was invaluable to this work. We also thank the Frontier Metrology Science Center, National Institute of Metrology, China, for the donation of materials used in the experiments. Any assistance that does not fall under author contributions or funding has been greatly appreciated.  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript:  
PSL Polystyrene Latex SSIS Institute Scanning Surface Inspection System SW Standard Wafer CFD Computational Fluid Dynamics SMPS Scanning Mobility Particle Sizer SEM Scanning Electron Microscopy CPC Condenser Particle Counter DMC Differential Mobility Classifier