Removal of Fine Particles from Wafer Surface by Pulse Air Jets [Translated]†

Abstract

Removal of fine particles from wafer surface by air jets was experimentally investigated in order to seek an effective surface-cleaning method which uses no cleaning liquids. Monodisperse polystyrene latex particles with diameter between 0.25 and 3.3 μm were deposited on a silicon wafer by gravitational settling and removed by air jets from a rectangular nozzle. Particles were blown off the moment the air jet struck the wafer surface, and afterwards no particle reentrainment occurred. This suggests that the sequential pulses of air jets are effective for the removal of fine particles. By exposure of wafer surface to sequential pulse air jets, particles with a diameter as small as 0.25μm were almost completely blown off the surface. The experimental results also indicated that the removal efficiency of particles per pulse air jet, which is the ratio of number of particles reentrained during an air jet exposure to that before the exposure, is kept constant for each exposure to sequential pulse air jets.† This report was originally printed in KAGAKU KOGAKU RONBUNSHU 19(1), 114-119 (1993) in Japanese, before being translated into English by KONA Editorial Committee with the permission of the editorial committee of the Soc. Chemical Engineers, Japan.