A physical method of surface cleaning has been developed using the jet of micron-sized ice particles in a low pressure impactor. The substrate to be cleaned was prepared by both applying organic films and depositing polystyrene （PS） particles on substrates. The PS particles, as a source of contamination, were produced with the average sizes ranging from 0.5 to 3 micrometers and narrow size distribution under well-controlled conditions. The particles were deposited uniformly and controllably by changing the deposition time, carrier gas flow rate, and substrate temperature. Major variables for removing both the films and contaminating particles were the removal time, chamber pressure, carrier gas flow rate, nozzle-to-substrate distance and number concentration of ice particles. We proposed two models on film-removal mechanism, which could be applied, depending on the kinetic energy of the ice particles and the hardness of the film. The ice-particle jet system, as a method of cleaning, was found so effective to remove physically both films and particles adhered to a wafer.

Ice-Particle Jet Wafer Cleaning Film Removal Monodisperse Particles Low-Pressure Impactor Particle Deposition

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