Temperature-dependent breakdown behavior in InP double heterojunction bipolar transistors (DHBTs) with InGaAs/InP composite collector

Temperature-dependent collector breakdown behavior in InP HBTs with an InGaAs/InP composite collector has been investigated. We have found that, in the layer structures studied, the device shows a positive temperature dependence of common-emitter breakdown at temperatures lower than 330 K due to the negative temperature dependence of impact ionization coefficient in InP. However, at higher temperatures, the contribution of InGaAs layer becomes important and a negative temperature dependence of collector breakdown is observed.