Low frequency noise characterization of self-aligned InP/InGaAs heterojunction bipolar transistors

Low frequency noise characterization of self-aligned InP/InGaAs heterojunction bipolar transistors (HBTs) is reported. The choice of HBTs with various emitter dimensions permits the investigation of the effect of the emitter size on the low frequency noise performance of these devices. It is found that the shape of the input referred current noise spectra is changing with bias conditions. This allows for the possibility of considering that the origin of this noise could be changing from recombination noise at low bias to diffusion or minority carrier trapping 1/f noise at high bias.