High-Rate Sputtering of Si and SiO₂ with Atomically Flat Surfaces by Using Ethanol Cluster Ion Beams

抄録

In order to investigate the interactions of ethanol cluster ion beams with solid surfaces, various kinds of substrates such as Si(111), SiO₂ and Au substrates were irradiated at different acceleration voltages and retarding voltages for ethanol cluster ions. RBS channeling measurement showed that the irradiation damage of the Si surfaces by the ethanol cluster ions was smaller than that by the Ar monomer ion irradiation at the same acceleration voltage. It was also found that the formation of damage-free surface was achieved by adjusting the acceleration voltage and the retarding voltage for the ethanol cluster ions. Furthermore, the sputtering process was investigated by changing the retarding voltage and the incident angle, and chemical sputtering was found to be predominant for the Si surfaces. The surface roughness decreased with increase of the retarding voltage, and it was less than 1.2 nm. On the other hand, for SiO₂ and Au surfaces, physical and lateral sputtering was achieved, and the sputtered depth decreased with increase of either the retarding voltage or the incident angle.