Effects of Electrostatic Discharge Stress on Electrical Properties of Bidirectional TVS Zener Diode with Abrupt Junctions

A bidirectional transient voltage suppressor (TVS) Zener diode was fabricated with abrupt junctions using the low-temperature epitaxy process. The effects of various electrostatic discharge (ESD) stresses on the electrical properties are demonstrated, such as the current­voltage (I­V) and 1/f noise power spectral density (PSD). Very sharp and uniform bidirectional multi-junctions result in good symmetric I­V behavior over a wide range of operating temperatures of 300­450K. The differential resistance in the breakdown region is only 0.23, and the reverse leakage current density is completely suppressed to 1.5 © 1014 A/m2. The thermal activation energy obtained from the Arrhenius plot is nearly equal to half the band gap of Si, indicating that the reverse leakage current is dominated by thermal generation at the depletion edges for the entire reverse bias regions. The manufacture bidirectional TVS devices exhibit excellent ESD robustness, regardless of the stress conditions of the human body model and electrical fast transient. However, a «4.5 kV machine model and «13 kV IEC61000-4-2 stresses led to severe damage of the epitaxially grown junction, resulting in rapid increases in both the reverse leakage current and 1/f noise PSD. [doi:10.2320/matertrans.M2013144]