LOW-FREQUENCY NOISE CHARACTERIZATION OF SELF-ALIGNED INP INGAAS HETEROJUNCTION BIPOLAR-TRANSISTORS/

Low frequency noise characterization of self-aligned InP/InGaAs hetero junction bipolar transistors (HBTs) is reported. The choice of HBTs wi th various emitter dimensions permits the investigation of the effect of the emitter size on the low frequency noise performance of these de vices. It is found that the shape of the input referred current noise spectra is changing with bias conditions. This allows for the possibil ity of considering that the origin of this noise could be changing fro m recombination noise at low bias to diffusion or minority carrier tra pping 1/f noise at high bias. (C) 1995 American Institute of Physics.