Surface Smoothing and etching by gas cluster ion beam

摘要

Ar and CO_2 gas cluster ion beam with a few nm size were generated by an adiabatic expansion through Laval nozzle. The existence and the mean size distribution of the cluster were analyzed by time-of-flight measurement. Crater induced by Ar cluster ion beam and crown-like hillock by CO_2 cluster ion impact on Si(100) were observed by an atomic force microcopy. CO_2 cluster ion was irradiated on Si at 25 kV with the variations of ion dose from 10~(10) to 10~(13) cluster ions(CI)/cm~2, at the flux of 109/cm~2 s. Through this isolated cluster ion impact, the interaction mechanism between cluster ion with solid surface was suggested to be made of three steps: surface embossment, surface sputtering and smoothing, and surface etching. Another surface smoothing and etching experiment using CO2 cluster ion beam were carried out over ITO/glass and Cr-masked Si_3N_4 thin film surfaces at 25 kV.