Structural analysis of integrated circuits using scanning laser ultrasonics

We present an analysis of a VLSI Circuit using the picosecond ultrasonics technique. This optical non-destructive technique is based on ultrasound generation and detection by ultrashort laser pulses. The experimental setup and methodology are analyzed. The influence of the protection layer for passivated circuits on the experimental results is described. The in-depth and lateral resolutions of the technique are illustrated by experimental results.