Impact of Various Scaling Techniques and Base Region Optimization on the Speed of Si-Ge HBT

Abstract: Nowadays SiGe HBTs are surpassing even the fastest III-V production devices in the GHz speed orbit. Scaling has been the prime source of supremacy behind the successful technology innovations. The impact of different Ge concentration of graded profile as well as The design and optimization of un-scaled and scaled SiGe HBTs on the key performance parameter which affect the speed parameter in GHz frequency range has been explored extensively, which have recently emerged as a tough competitor for RF and mixed-signal applications. Both vertical and lateral scaling affects the device parameters. The impact of lateral scaling on cut off frequency is not as prominent as vertical scaling, but a certain level of lateral scaling needs to go along with vertical scaling Since maximum frequency of oscillation is absolutely associated to cut off frequency, the remuneration of vertical scaling on cut off frequency also apply to maximum frequency of oscillation, although the impact level is comparatively lower. However, maximum frequency of oscillation depends on RB and CCB, too, which are truly degraded by vertical scaling. The simulated results of un-scaled and scaled SiGe HBT are compared and contrasted.