Experimental investigation of Zener diode reliability under pulsed Electrical Overstress (EOS)

• An experimental setup for reproducing the influence of EOS waveforms is developed.
• Pulsed EOS tests respecting to the amplitude, duration and periodicity are fulfilled.
• Characteristics degradation due to EOS is observed and analyzed.
• A physical interpretation of the observed degradation is addressed.
• The signature of EOS is reproduced according to the failure analysis after the tests.

In this paper, the characteristics degradation due to the Electrical Overstress (EOS) on Zener diode is analyzed. To characterize this misunderstood effect, relevant experimental setup reproducing the influences of EOS waveforms is developed. Basic EOS tests of Zener diode BZX84B6V8 versus the stress voltage amplitude and pulse width are fulfilled. Subsequently, analyses of the time-dependent voltage across the diode in function of the stress voltage are performed. To cope with the EOS malfunctioning aspect, I–V characteristics are plotted along the stress time and a physical interpretation of the observed electrical responses is also addressed. It was pointed out that this undesired electrical degradation during the tests can be substantially due to the thermal action on the diode junction over its tolerated normal values.