ElectroStatic Discharge Fault Localization by Laser Probing

This paper deals with the localization of ElectroStatic Discharge (ESD) failure in digital circuits by thermoelastic laser probing. After ESD simulation on a NAND TTL LS circuit, the device was scanned using an interferometric laser probe. In sine wave regime the surface displacement induced by the leakage current was recorded. The heat source acts as a hot spot inducing a thermal expansion in its neighborhood. This expansion, whose magnitude varies from several hundred to a few picometers (10⁻¹²m), allows the localization of the leakage region corresponding to the ESD failure area.