Determination of reliability on MOCVD grown InGaP/GaAs HBT´s under both thermal and current acceleration stresses

Conexant´s reliability infrastructure was utilized to determine the reliability of next generation InGaP/GaAs heterojunction bipolar transistors (HBT´s). The investigated InGaP HBT´s were subjected to stresses at three junction temperatures and three current densities, in order to extract both thermal and current acceleration factors. The primary failure mode we identified for all stress conditions is sudden Beta degradation characterized by an increase of base current over time. The thermal activation energy was extracted to be 0.97 eV for Beta degradation. The current acceleration of transistor lifetime is modeled as a power law relationship and we have extracted a square root dependence of lifetime on current density.