A reliability comparison of InGaP/GaAs HBTs with and without passivation ledge

Abstract

InGaP/GaAs heterojunction bipolar transistors (HBTs) with and without passivation ledge in the extrinsic base region were investigated. Gummel plot changes before and after reliability testing were compared. The experimental results demonstrated that the devices featuring the lower quality of the extrinsic base surface are more sensitive to a temperature–current stress. The HBTs with a passivation ledge have an activation energy of 1.41 eV and a mean time to failure (MTTF) of 10 6 h whereas the HBTs without passivation ledge have an activation energy of 1.24 eV and a MTTF of 10 5 h.