Development of ion and electron dual focused beam apparatus for high spatial resolution three-dimensional microanalysis of solid materials

We constructed an ion and electron dual focused beam apparatus to develop a novel three-dimensional (3D) microanalysis technique. In this method, a Ga focused ion beam (Ga FIB) is used as a tool for successive cross sectioning of the sample in the “shave-off” mode, while an electron beam (EB) is used as a primary probe for Auger mapping of the cross sections. Application of postionization with EB to Ga-FIB secondary ion mass and two-dimensional (2D) elemental mapping with Ga-FIB-induced Auger electrons are also in the scope of the apparatus. The 3D microanalysis was applied to a bonding wire on an integrated circuit (IC). A series of EB-induced sample current images of the successive cross sections were obtained as a function of the cross-sectioning position. This result showed the capability to realize the 3D Auger microanalysis. Two-dimensional elemental mapping with Ga-FIB-induced Auger electrons was realized for the first time on the IC surface. Its applicability to surface analysis was evaluated.