Low-frequency noise in millimeter-wave Si/SiGe heterojunction bipolar transistors

In this paper we report on the low-frequency (LF) noise properties of Si/SiGe HBT's. Our results indicate that these devices exhibit very interesting LF noise performance which compares well with those obtained for Si BJT's. However, further improvements of the input referred noise current are still needed and our investigations show that they could be achieved through a reduction of the recombination processes at the emitter-base heterojunction and at the emitter periphery.<>