Impact of ESD-induced sort drain junction damage on CMOS product lifetime

The impact of ESD-induced soft drain junction damage on product lifetime wa s investigated. Several thousand input-output (IO) pads of a 0.35 mu m CMOS IC were stressed by ESD (electrostatic discharge) and subsequently subject ed to bakes, ESD re-stress and high temperature operating life tests. While the ESD-induced soft drain junction damage appears to be stable versus tem perature stress and ESD-re-stress, it results in early failures during acce lerated operating life tests. These lifetest failures are caused by breakdo wn of the gate oxide which was left unbroken during the ESD stress that cau sed: the ESD-induced soft drain junction damage. Thus, ESD-induced soft dra in junction damage might cause a reliability risk (latent ESD failure). Con sequently, it needs to be avoided by assuring a sufficient robustness of th e IC against this ESD damage mechanism. A leakage current criterion of 1 mu A is rather large to detect this kind of damage after ESD stress. (C) 2000 Elsevier Science Ltd. All rights reserved.