Narrow Results

The change of shape and elemental concentration of cellular samples in In-Air micro PIXE analysis was investigated. Cultured bovine aortic endothelial cells were analyzed in the atmosphere by using 2.6 MeV proton micro-beams. The shape of cross-sections of cells was not so much distorted by beam irradiation and the concentrations of trace elements did not change too, except for S. The concentration of S changed with strongly depending on the temperature rise due to beam irradiation.

A focused ion beam (FIB) was successfully applied to prepare cross-sectional samples for transmission electron microscopy (TEM), scanning TEM (STEM), scanning electron microscopy (SEM), and scanning ion microscopy (SIM). The FIB milling has been prospectively applied also to nanofabrication. The FIB allows to mill with high accuracy in positioning, being in contrast with a broad ion beam with poor accuracy. Controlling beam conditions of ion pixel-dose (or pixel dwell time) and FIB scanning direction/velocity, and sample tilt/rotation, we can extend the FIB milling from cross-sectioning to three-dimensional (3D) fabrication. We review inherent characteristics of the FIB milling such as positioning accuracy, milling speed, uniformity of cross-section, beam damage, and secondary electron emission. Discussions are mainly held from a viewpoint of interaction of ion beam with solids.