Reverse Current Conduction Mechanism of Transient Voltage Suppression Diode under Electrostatic Discharge Stress

Abstract

A transient voltage suppression (TVS) diode with abrupt junctions was fabricated using low-temperature epitaxy. The effect of electrostatic discharge (ESD) stress on the reverse leakage current conductive mechanism of the TVS diode was investigated using IEC61000-4-2 (IEC) standard analysis, in accordance with temperature-dependent current-voltage (I-V) characteristics. The fabricated TVS diode showed excellent ESD robustness, with negligible degradation up to «19.5 kV and failure at «20 kV stress. The ESD stress evidently led to the generation of shallow and deep defect states in the depletion region located 0.52­1.08 eV below the conduction band, and these states served as a main contributor to the resulting reverse leakage current. In devices to which IEC peak voltage stresses of less than «19.5 kV had been applied, reverse conduction was dominated by generation-recombination current; the application of the «20 kV failure stress caused reverse conduction to become dominated by a combination of tunneling current via deep defects and Poole-Frenkel barrier lowering. The proposed TVS can serve as a highly stable and reliable ESD protector of electronic components, serving an evolving need in nanoscale technology. [doi:10.2320/matertrans.M2014214]