Through Silicon Via (TSV) defect investigations using lateral emission microscopy

Infra-red photoemission microscopy has been applied for the localization of defects in 3D integrated circuits containing Through Silicon Vias (TSVs). For these investigations, the familiar (planar) emission microscopy configuration was extended to allow imaging and emission microscopy on vertical TSV sidewalls, from versatile 3D viewpoints. Flexible viewing orientation was achieved by introducing an additional reflecting surface into the optical path. Precise alignment of the angle of incidence at the air–silicon interface, with sufficient accuracy to ensure no problematic refraction-related errors, was possible using this experimental set-up. Three examples are presented, showing defect localizations and underlying physical leakage mechanisms in TSV structures.