Epitaxial (epi) stacking faults on silicon wafers were investigated by combining different surface analytical methods. Automatic scanning electron microscope energy-dispersive X-ray spectroscopy analysis provided an overview of the defect situation on the wafer surface (coordinates and composition) before information on the topography by atomic force microscope and data on the stress fields of epi defects by micro-Raman spectroscopy were collected. Sputtering of the defects was carried out by argon or oxygen ions to find the cause of the defect. Delaminated particles were analyzed by Auger electron spectroscopy and time-of-flight secondary ion mass spectrometry. The results demonstrate that the geometrical type of an epi defect depends on the chemical composition and the physical phase of the contamination. (C) 2008 The Electrochemical Society.