Study of temperature dependence of turn-on voltages IN III-V HBTS

We report variation of collector and base currents with temperature from 80K-400K on InGaAs/GaAs and AlGaAs/GaAs HBTs. The results obtained showed clearly that, among all the material systems studied, the InP/ In 0.53 Ga 0.47 As HBTs have the lowest turn-on voltage (0.1V). This is in good agreement with the theoretical prediction. Although marked differences in the values of turn-on, Vturn-on for InGaAs-and GaAs-based HBTs were observed, voltage-thermal feedback coefficients of Vturn-on for all devices, irrespective of their material systems, do not differ considerably