State-of-the-art microelectronics is based on silicon integrated circu
its with constantly shrinking minimal lateral dimensions. SiGe heterod
evices offer compatibility with this silicon technology and also utili
zation of heterostructure effects. In this review mainly the existing
device concepts, the advantages and limits of the SiGe/Si system and t
he realization of device structures by molecular beam epitaxy are desc
ribed.