This study investigates the HVAC system connected to photo-processing equipment within semiconductor manufacturing, focusing on quality issues caused by particle contamination. Among the eight primary semiconductor manufacturing steps, the photo proce...
This study investigates the HVAC system connected to photo-processing equipment within semiconductor manufacturing, focusing on quality issues caused by particle contamination. Among the eight primary semiconductor manufacturing steps, the photo process is particularly vulnerable to contamination issues. During this process, the coating stage is followed by exposure and then baking, where airborne contaminants and particles are often generated. To enhance semiconductor quality, this research analyzes the behavior of these particles in the HVAC duct system and aims to improve contamination control within the ductwork, particularly by addressing the effects of PAH droplet deposition on dampers, which increases pressure drop in exhaust pipes.Previous research has explored factors related to particle deposition in ducts, such as the Stokes number and deposition velocity. In this study, we selected specific equipment and duct systems as the basis for computational modeling. Using Inventor, a 3D model of the HVAC duct connected to the photo 51equipment was created. Fluent was used to generate a fine 3D mesh grid, and mesh independence was validated using Mean Absolute Percentage Error (MAPE) analysis.To understand the properties of particles generated during the baking stage, component analysis was conducted, and existing studies were reviewed to investigate the principles of fume generation during baking. Data collected from the equipment was used to set boundary conditions, and mesh quality was optimized to improve the accuracy of the numerical simulations. Fluent’s Discrete Phase Model (DPM) and Eulerian Wall Film (EWF) models were applied to simulate particle deposition on duct and damper surfaces. The analysis focused on quantifying pressure and pressure losses at the duct inlet as a function of particle deposition.Experimental data from the actual system were compared with simulation results, and a regression analysis was performed using Spotfire to evaluate trends in pressure loss. Error rates were calculated using Percent Bias (PBIAS) with a maximum of 4% to validate the results. This analysis ultimately revealed the relationship between pressure loss rates at duct inlets and the extent of particle deposition within the system. Notably, the pressure loss rate quadruples as the distance from the outlet increases, and particle deposits accumulate more on dampers closer to the exhaust outlet. Additionally, particle deposition is more pronounced at the edge of dampers than at the center.