There is discussed an influence of n-p-n HBT scaling on its RF performance in the article. The behaviour of cut-off and maximum frequency of DUT at the transition from 0.18 um down to 0.09 um BiCMOS technology is demonstrated, its dependence from construction and technological variations of the heterojunction bipolar transistor, as well. It was shown, that the approach called "direct" scaling appeared to be inappropriate as a frequency-increase method and some constructive and technological recommendations were discussed, including Ge profile shape, impact of deep collector implantation dose and cap-layer thickness.

Keywords: silicon-germanium, SiGe HBT, BiCMOS, RF performance

`

Keywords: