Time-resolved capacitive coupling voltage contrast—a new voltage measurement technique for passivated devices

A scanning electron microscope is used in the voltage contrast mode to examine dynamic voltages on passivated integrated circuits. At low primary electron beam energies negative voltage transients produce a capacitive coupling voltage contrast flash visible through passivation layers. The flash decay time is related to the amplitude of the voltage transient. This new voltage measuring method is called time-resolved capacitive coupling voltage contrast. Preliminary results yield voltage calibration curves with a standard error of 45 mV or lower.