Low frequency noise of InP/InGaAs heterojunction bipolar transistors

In this paper, we have studied the 1/f low frequency noise of self-aligned and non self-aligned InP/InGaAs heterojunction bipolar transistors (HBTs), The total noise of transistor is modeled by two current noise sources. The evolution with geometry, technological process and bias, of the current spe ctral densities referred to the input and output of the devices, permit us to locate the noise sources. Noise is mainly generated in the intrinsic tra nsistor, and an extra noise perimetric source has been identified for the s ell-aligned transistors at the emitter periphery.