Surface Processing by Polyatomic Cluster Ion Beams

Abstract

We produced polyatomic clusters such as ethanol and water clusters by an adiabatic expansion phenomenon of vaporized material. The cluster ions were irradiated by changing the incident energy on various kinds of substrates such as mica, Si(100), SiO2 and photo-resist substrates. AFM observation showed that irradiation trace with the diameter of approximately 20 nm was formed on mica substrates by ethanol cluster ion irradiation. Also, it showed that surface roughness of Si(100) substrates irradiated was less than 1 nm, even though the surface was sputtered by ethanol and water cluster ion irradiation. Furthermore, RBS channeling measurement showed that the irradiation damage of Si(100) surfaces sputtered by ethanol and water cluster ions was smaller than that by the Ar monomer ion irradiation. With regards to sputtering and patterning, the sputtered depth of Si(100), SiO2 and photo-resist surfaces by ethanol cluster ion irradiation increased with increase of the acceleration voltage. The sputtering yield of the Si(100) surface was a few hundreds times higher than that by Ar monomer ion irradiation at the same acceleration voltage. In addition, micro-patterning was performed on the Si(100) surface, and sharp-edged patterns with a line-width of 0.5 μm to 3 μm were achieved by ethanol cluster ion irradiation. [DOI: 10.1380/ejssnt.2011.168]