Novel Collector Structure Enabling Low-Cost Millimeter-Wave SiGe:C BiCMOS Technology

A millimeter-wave selective-epi, SiGe:C HBT is described, utilizing a novel, low-cost collector construction. A cutoff frequency (fT) of 200GHz and a maximum oscillation frequency (fMAX) of 300GHz is achieved using a self-aligned selective-epi base structure. For a SiGe:C HBT, this is the highest known fMAX obtained without the use of buried layer or deep trench isolation.