WP2 results for the year 2
ST: A first shrinking phase on the HBT of ST’s most advanced high-speed SiGe BiCMOS technology (BiCMOS9MW) led in the first year of DOTFIVE to a 260 / 350 GHz fT / fmax technology, called B3T. Using still a conventional SA selective epitaxial base HBT, a second shrinking phase resulted in DOTFIVE to the B4T technology providing a maximum oscillation frequency fmax of 400 GHz and a transit frequency fT of 265 GHz. These outstanding performance data have been obtained together with a collector emitter breakdown voltage BVCEO of 1.5 V and a collector base breakdown voltage BVCBO of 6.0 V. Even better results, e.g. wafer average values of 422 GHz for fmax and 283 GHz for fT have been demonstrated recently by ST using a more optimized process.
IFX: In DOTFIVE various improvements on IFX’s SiGe HBT technology B7HF200 have been performed. The technology features also a SA selective epitaxial base transistor and is used for example in automotive radar applications at 77 GHz. The improvements were new transistor layouts with tighter design rules, a reduction of emitter window width, a shallower collector as well as new SiGe base profiles with 30% Ge content. The new SiGe HBTs have provided a CML ring oscillator gate delay time of 2.7 ps together with a maximum oscillation frequency of 320 GHz and a transit frequency of 225 GHz.