Performance and structure degradations of SiGe HBT after electromagnetic field stress

Abstract

This paper addresses failure analysis of electromagnetic field stress effects on SiGe HBTs reliability issues, examining the relation ship between the stress-induced current and device structure degradations. The origin of leakage currents in failed transistors has been studied by complementary failure analysis techniques. Characterization of the structure after aging was performed by Transmission Electron Microscopy (TEM) and Energy Dispersive Spectroscopy (EDS). We found clearly dislocations and interface deformation of the Titanium thin film (Ti) of all contacts. Based on the coupling of high current density and thermal effects due to Joule heating, device failures are explained. These disorders may explain the origin the large shifting of the dynamic characteristics of failed transistors.