Abstract: In this talk the foundations are discussed on the past and future of the semiconductor germanium (Ge). Germanium transistors were the starting point (1948) of the exponential microelectronics growth but roughly after a decade replaced by silicon (Si) and other semiconductor materials. New demands for a green, less power consuming electronics speed up research on device/ circuit concepts, which combine the advantages of Si CMOS and heterostructures with novel design freedoms. Microelectronics starts with Ge (1948). Monolithic Integra-tion skips bulk Ge in favour of bulk Si (from 1960 on). Low charge density oxide/ Si interfaces allowed realization of integration friendly MOS transistors.High complexity and low cost integration of digital CMOS circuits pushed logic functions into nearly all applications. Ge/Si Heterostructures: Low Power Consumption Devices and Photonics-Electronics Merger(from 2005 on). The physical concept was based on heterostructure band offsets, on quantum size effects and on band structure modifications by elastic distortions. Realization of nanometer heterostructure by epitaxy methods paved the way to silicon based Ge/Si devices. Strained Ge/Si quantum structures promise the dramatic mobility increase needed for power saving electronics. High speed detectors and modulators, and the recently demonstrated Ge/Si laser will be the base of a Si based photonics/ electronics merger.

Biography：Prof. Erich Kasper received the Ph.D. degree in physics from the University of Graz, Graz, Austria, in 1971. His dissertation thesis concerned electrical properties of dislocations in silicon. He was active as a Scientist with the research laboratories of the companies Telefunken, AEG and Daimler-Benz. His main research concerned solid-state analysis by X-ray topography and electron microscopy, material synthesis by MBE, and semiconductor device preparation for microwave applications. From 1987 on, he was responsible for novel silicon devices and technology with Daimler-Benz Research, Ulm, Germany, with a main emphasis on SiGe/Si-based heterostructures for fast transistors (heterobipolar transistor-HBT, modulation doped field effect transistor MODFET) and opto-electronic transceivers (ultrathin superlattice). Since 1993, he has been with the University of Stuttgart, Stuttgart, Germany, as Professor of Electrotechnical Engineering and Head of the Institute of Semiconductor Engineering. His main interest is directed to silicon-based nanoelectronics, integration of millimeter-wave circuits, and SiGe/Si quantum-well devices. In 2008 he retired as Institute Head but retained with University of Stuttgart as Research Professor. He was appointed as Guest Professor at Huazhong University of Science and Technology(HUST), Wuhan, China in 2009, and he continues to lecture at the Montanuniversitaet in Leoben, Austria. Recent activities focus on exploitation of research results, on application of Ge/Si for photovoltaics and energy harvesting and on mm-wave imaging.