Small particles in ULSI devices are one of the key causes for affecting device yield. This is especially true since modern devices are shrinking in all dimensions and the critical size for ‘killer’ particles is also shrinking. It is increasingly challenging to identify the root cause of particle contamination in terms of locating and identifying the particles. A precision cross section through the particles is required to be able to identify at which processing step the particles occurred and an energy dispersive spectroscopy (EDS) microanalysis usually helps identify the source. This paper focuses on the methodology for carrying out submicron defect and particle analysis. In addition to processing knowledge, it demonstrates the importance of techniques such as scanning electron microscopy (SEM), EDS, and focused ion beam (FIB). The analysis of microcorrosion observed after third metal deposition, and submicron titanium particles after metal etch are used as vehicles to illustrate the procedure of submicron particle analysis.