Low-frequency noise in UHV/CVD Si- and SiGe-base bipolar transistors

In this work we present the first comprehensive investigation of the low-frequency noise characteristics of an advanced epitaxial Si- and SiGe-base bipolar technology grown by the UHV/CVD technique. The magnitude of the 1/f noise is comparable for SiGe HBTs and Si BJTs for identical bias, geometry, and temperature, indicating that the use of thermodynamically stable SiGe strained-layers does not degrade transistor noise performance. In some of the Si and SiGe samples we have observed random telegraph signals (RTS) associated with excess generation-recombination (G/R) noise. Temperature measurements have been made to extract activation energies of the associated G/R centers.