PARTICLE DEPOSITION ON SILICON-WAFERS DURING WET CLEANING PROCESSES

A model of particle contamination on Si wafers during wet cleaning processes has been established. This model takes into account both the van der Waals and electrostatic forces and has the particularity of assimilating the particles to pin-point charges subjected to the electrical field generated by the wafers. The hydrodynamics generated by the passage of the wafers through the air-liquid interface is also taken into account. This approach highlights two contamination mechanisms: at the air-liquid interface and within the solution and also the physical parameters controlling the depositions. All of these parameters were characterized in water for specific particles (C, Si3N4, SiO2, SiC, Al2O3) and specific wafers (p-doped, [100] oriented, with hydrophilic and hydrophobic surfaces). These measurements enabled qualitative forecasts of interface particle contamination and quantitative forecasts of particle contamination in solution to be obtained.