The temperature-dependent characteristics of an InGaP/GaAs heterojunction bipolar transistor (HBT) with an emitter-edge-thinning structure are studied and demonstrated. Based on the use of the emitter-edge-thinning structure, higher current gain and lower base surface-recombination current density over the measured temperature range (300-400 K) are obtained. In addition, the device shows the improved thermal stability on dc current gain performance. Therefore, the studied HBT device with an emitter-edge-thinning structure has promise for low-power and higher temperature electronic applications. (c) 2006 The Electrochemical Society.