Abstract :
An interesting two-step passivation (with ledge structure and sulphide based chemical treatment) on base surface, for the first time, is
demonstrated to study the temperature-dependent DC characteristics and noise performance of an InGaP/GaAs heterojunction bipolar transistor
(HBT). Improved transistor behaviors on maximum current gain bmax, offset voltage DVCE, and emitter size effect are obtained by using the twostep
passivation. Moreover, the device with the two-step passivation exhibits relatively temperature-independent and improved thermal stable
performances as the temperature is increased. Therefore, the two-step passivationed device can be used for high-temperature and low-power
electronics applications.
