Structural Characterization of Processed Silicon Wafers

Two techniques, chemical etching and X-ray diffraction, for the characterization of process-induced defects in silicon wafers are illustrated. The types of etchants used to reveal various defects are reviewed. The use of a Lang camera for the measurements Of bulk defects and mechanical stress in silicon wafers is presented. Examples are given demonstrating the use of these two techniques: to monitor the type and density of defects as well as wafer stress in several key steps during wafer processing. Process-induced defects which limit the device yield are also presented.