ESD-induced noncatastrophic damage in power MOSFETs

Abstract

Electrostatic discharge (ESD) may, depending on the energy of the pulse, cause either catastrophic failures or degradation of MOSFETs. Effects of noncatastrophic positive Human-Body Model (HBM) ESD stress at the gate of power MOSFETs are investigated in this work. Noncatastrophic damage is manifested in the form of positive charge trapping in the gate oxide. In p-channel devices used in this study, the charge injection and trapping occur predominantly in the gate oxide areas lying above the p-body region. In p-channel devices used, the charge is injected mainly from the p-drain region. Based on the polarity of the pulse and the regions observed to contribute to charge injection, a model of ESD-induced charge injection from the silicon into the oxide is proposed. Finally, the effects of noncatastrophic ESD events on the radiation response of n-channel power MOSFETs are reported.