Physics-based hot-carrier degradation model for SiGe HBTs

We present hot-carrier degradation analysis for SiGe heterojunction bipolar transistors based on deterministic solutions of the Boltzmann transport equations for a coupled system of electrons and holes. The full-band transport model provides the distribution function of the charge carriers interacting with the passivated Si-H bonds along the Si/SiO
2
interface. Investigation of the density of hot carriers along the emitter-base spacer oxide interface asserts the significant role of hot holes in the long-term degradation of SiGe HBTs under DC mixed-mode stress conditions. The creation of interface trap states by hot carriers is calculated by an energy-driven microscopic model. These traps increase the forward base current via Shockley-Read-Hall recombination and degrade the overall device performance.