The effect of geometry in the characterization of barrier profile in vias by transmission electron microscopy

Characterization of the profile and thickness of barrier layers in cylindrical vias by cross-sectional transmission electron microscopy (TEM) is crucial for understanding the behavior of Cu interconnects and is becoming a challenge for the 0.13 /spl mu/m node and below. In this study, we demonstrate how the geometry of the TEM sample affects the contrast of the barrier layer and propose guidelines for TEM sample preparation and image interpretation.