Investigation of temperature-dependent performances of InP/In0.53Ga0.34Al0.13As heterojunction bipolar transistors

Temperature-dependent de performances of lattice-matched InP/InGaAlAs heter ojunction bipolar transistors (HBTs) using the InGaAlAs quaternary alloy as the base and collector layers are studied and reported. When compared with conventional InP/InGaAs HBTs, the device studied exhibits a higher common- emitter breakdown voltage and a lower output conductance: even at high temp erature. The variations of offset voltage and ideality factor at different temperatures have been analysed. In addition, with decreasing temperature f rom 25 degreesC toward - 196 degreesC, an irregular temperature behaviour o f current gain is observed. At high current levels, the temperature-depende nt current gain is mainly determined by the reduced reverse hole injection current. As the current level is lowered, the dominance of reverse hole inj ection current is correspondingly replaced by the recombination current.