Deposition of Charged Particles on a Flat Plate in Parallel Flow in the Presence of an Electric Field

Deposition velocity of charged particles onto a horizontal flat plate in parallel airflow in the presence of an electric field was numerically investigated by employing a Lagrangian particle tracking approach. The plate length was set as 450 mm, i.e., the characteristic length of the next generation wafer. Either the face-up or the face-down critical surface was considered. The electric field strength and the particle density were varied. The particle deposition velocity was greatly influenced by the electric field strength for particles smaller than approximately 0.1 μm. The influence of the particle density was significant for particles larger than about 0.1 μm. In case of the face-down critical surface, the deposition velocity was greatly reduced for micrometer-sized particles, whereas it was estimated to be relatively high for sub-micrometer sized particles due to attractive electrophoresis and Brownian diffusion.