Highly Sensitive OBIRCH System for Fault Localization and Defect Detection

摘要

We have improved the optical beam induced resis- tance change (OBIRCH) system so as to detect (1) a current path as small as 10-50 μA from the rear side of a chip, (2) current paths in silicide lines as narrow as 0.2 μm, (3) high-resistance Ti-depleted polysilicon regions in 0.2 μm wide silicide lines, and (4) high-resis- tance amorphous thin layers as thin as a few nanometers at the bottoms of vias. All detections were possible even in observation areas as wide as 5 mm × 5 mm. The physical causes of these detections were charac- terized by focused ion beam and transmission electron microscopy.