ABSTRACT
By adding Ge to Si new properties of the material can be created, which offer applications in a wide
range of electronic devices. In this way the capability of Si electronics is widened. The SiGe hetero-
junction bipolar transistor (SiGe HBT), which makes use of SiGe bandgap engineering and strain,
technologies SiGe and Si strained layers are becoming increasingly important, for instance, for higher
mobility channel material [3, 4]. After the first report on growth of epitaxial SiGe layers dating back
became important milestones for the development of SiGe strained-layer epitaxy. After demonstrating
the stability and high-volume production capability of SiGe strained-layer epitaxy for HBT base
deposition using ultrahigh vacuum CVD (UHV CVD) [8] and low-pressure CVD (LP CVD) [9] the
low-temperature epitaxial deposition of SiGe by CVD was ready to be used in manufacturing. Especially,
the demonstration of the ability to grow device-quality SiGe layers without using UHV deposition
techniques [10-14] has greatly influenced the development of strained-layer deposition process technol-
ogy and tools.
