ABSTRACT
SiGe HBTs are far and away the most mature Si heterostructure devices and not surprisingly the most
completely researched and discussed in the technical literature. That is not to say that we completely
understand the SiGe HBT, and new effects and nuances of operation are still being uncovered year-by-
year as transistor scaling advances and application targets march steadily upward in frequency and
sophistication. There is still much to learn. Nevertheless, a large body of literature on SiGe HBT
operation does exist, across an amazingly diverse set of topics, ranging from basic transistor physics,
to noise, to radiation effects, to simulation. This section’s comprehensive treatment of SiGe HBTs begins
with Chapter 4.2, ‘‘Device Physics,’’ by J.D. Cressler of Georgia Tech., and addresses perturbations to that
first-order theory in Chapter 4.3, ‘‘Second-Order Effects,’’ by J.D. Cressler of Georgia Tech. Chapters 4.4
to 4.7 address mixed-signal noise and linearity in SiGe HBTs, including: Chapter 4.4, ‘‘Low-Frequency
Noise,’’ by G. Niu of Auburn University; Chapter 4.5, ‘‘Broadband Noise,’’ by D. Greenberg of IBM
Microelectronics; Chapter 4.6, ‘‘Microscopic Noise Simulation,’’ by G. Niu of Auburn University; and
Chapter 4.7, ‘‘Linearity,’’ by G. Niu of Auburn University.
