ABSTRACT
The high-speed Silicon-germanium heterojunction bipolar transistor (SiGe HBT) is one such example. Since the first sale in 1998, SiGe HBTs have seen increasing applications in wireless communications, hard disk drives, optical disk drives for CD, DVD and Blu-ray disk, thin-film transistor displays, high-resolution video, and optical networking components. PNP SiGe HBTs are much less explored due to the inherently slower minority carrier transport and thus lower frequency response. However, complementary SiGe HBTs have many advantages over an NPN-only technology for numerous analog applications requiring high speeds, low noises, and large voltage swings. Therefore, to achieve narrow base doping, it is a must to understand and predict P diffusion and segregation in strained SiGe. Dopant profile engineering during semiconductor fabrication can be categorized into two steps: one is the initial introduction of dopants such as pre-deposition, ion-implantation and in-situ doping; the other is the control of diffusion during high-temperature process steps.
