Physical and chemical sputterings of solid surfaces irradiated by ethanol cluster ion beams

In order to clarify the interactions of ethanol cluster ion beams with solid surfaces, sputtering processes for Si, Si O2 and Au surfaces were investigated by changing the acceleration voltage, the retarding voltage, and the incident angle. For the case of the normal incidence, the sputtered depth increased with increase of the acceleration voltage, and the sputtering ratio of Si to Si O2 was approximately 10 at an acceleration voltage of 9 kV. Furthermore, with regard to the incident angle dependence, the sputtered depth for the Si surfaces had a maximum value at an incident angle between 10° and 60°. On the other hand, for the case of the physical sputtering by ethanol cluster ion irradiation on Au surfaces, the sputtered depth decreased with increase of the incident angle. With regard to the retarding voltage dependence, the sputtered depth had a maximum value for the Si surfaces, and the retarding voltage corresponding to the peak value changed according to the acceleration voltage applied. In addition, for the case of Au surfaces, the sputtered depth decreased with increase of the retarding voltage, and the physical sputtering was influenced by the minimum size of the cluster.