DEVELOPMENT OF 3-DIMENSIONAL MICROANALYSI S USING ION AND ELECTRON DUAL-FOCUSED BEAMS

The failure analysis of electronic devices and deduction of the emissi on origins of dust particles in clean processes or in urban air requir e a precise three-dimensional (3D) microanalysis method. The most indi spensable demand for such 3D microanalysis is the applicability to sam ples with arbitrary shapes and heterogeneity. We are developing a nove l 3D microanalysis method which will satisfy these requirements. Our m ethod employs the combination of micro-cross-sectioning of a sample us ing a Ga focused ion beam (Ga FIB) and Auger mapping of the cross sect ion using an electron beam (EB). On the basis of this concept, we cons tructed an ion and electron dual-focused beam apparatus. The Ga MB and EB are perpendicularly directed to a sample to define simply the 3D c oordinates from the steering of the two beams. Preliminary experiments on the non-element specific 3D imaging of an IC using an EB-induced s ample current signal showed a favorable result concerning the reproduc ibility of the 3D structure within the analysis volume. Furthermore, t he contamination of the analytical surface (cross section) due to prim ary Ga implantation and the redeposition of sputtered materials were f ound to be greatly reduced in our cross-sectioning method.