PARTICLE DEPOSITION ON SILICON-WAFERS DURING WET CLEANING PROCESSES

A model of particle contamination on Si wafers during wet cleaning pro cesses has been established. This model takes into account both the va n der Waals and electrostatic forces and has the particularity of assi milating the particles to pin-point charges subjected to the electrica l field generated by the wafers. The hydrodynamics generated by the pa ssage of the wafers through the air-liquid interface is also taken int o account. This approach highlights two contamination mechanisms: at t he air-liquid interface and within the solution and also the physical parameters controlling the depositions. All of these parameters were c haracterized in water for specific particles (C, Si3N4, SiO2, SiC, Al2 O3) and specific wafers (p-doped, [100] oriented, with hydrophilic and hydrophobic surfaces). These measurements enabled qualitative forecas ts of interface particle contamination and quantitative forecasts of p article contamination in solution to be obtained.