Irradiation effects of water cluster ion beam on PMMA surface

We investigated the irradiation effects of a water cluster ion beam on a PMMA surface. The incident angle dependence of the sputter depth of the PMMA surface induced by the irradiation of a water cluster ion beam was measured. The sputter depth had a broad peak around the incident angle of 60°. The surface roughness caused by the irradiation of the water cluster ion beam was small compared with the sputter depth.