Size analysis of ethanol cluster ions and their sputtering effects on solid surfaces

When vapors of liquid materials such as ethanol were ejected through a nozzle into a vacuum region, ethanol clusters were produced at the vapor pressures larger than 1 atm. The cluster size measured by the TOF method was distributed between a few hundreds and a few thousands, which was different depending on the vapor pressure. Several kinds of solid surfaces such as Si(100) and metal surfaces were irradiated at different acceleration voltages with ethanol cluster ion beams, and chemical and physical sputtering with a high sputtering yield was achieved. In addition, the sputtered surfaces were very flat at an atomic level. The dependence of the sputtered depth on the incident angle of the ethanol cluster ion beams was investigated for the Si(100) surfaces. The sputtered depth had a peak value at an incident angle less than 60 degrees, and the incident angle corresponding to the peak value decreased with decreasing acceleration voltage.