Low-Frequency Noise in Advanced SiGe:C HBTs—Part I: Analysis

In this paper, we present extensive characterization of low-frequency noise in advanced silicon germanium heterojunction bipolar transistors. We demonstrate the extraction methodology of base and collector noise spectral densities for a wide range of transistor geometries. In addition to 1/f noise, generation-recombination (G-R) mechanisms are observed at low bias in the base current noise. Their existence is confirmed by Random Telegraph Signal (RTS) noise measurements. 1/f and G-R components are extracted from the base current noise spectra and their bias dependencies are studied. Finally, base current noise spectral densities measured at the same base current density in different geometries are compared to study the individual contribution of 1/f noise from the periphery as well as the intrinsic device. Part II of this paper will discuss the modeling aspects and noise correlation.