Feasibility of a New Atom Probe Specimen Preparation Method Using a Focused Ion Beam

Abstract

Specimens for three-dimensional atom probe (3DAP) analysis must be needle-shaped and the apex of specimen is primarily fabricated by focused ion beam (FIB). In the specimen preparation by FIB, the gallium ions are generally implanted into the surface region of the specimen during the irradiations of the ions. Therefore, the surface structure of the specimen is disarranged and amorphous. This phenomenon makes it difficult to reconstruct a three-dimensional image of the specimen. The implantation is caused by irradiating the apex of the specimen with FIB. In this study, we propose a new specimen preparation method in which FIB is irradiated from behind the needle specimen due to avoids the implantation of gallium ions. The assembly in this method was installed in the FIB instrument. The specimens were fabricated by means of the conventional and proposed methods and analyzed by atom probe in our laboratory. It was shown that not only the gallium implantation but also the rupture of specimen were inhibited by the proposed method. [DOI: 10.1380/ejssnt.2009.863]