Si versus Ge for future microelectronics

The quest for higher performance of scaled down technologies resulted in the use of high-mobility substrates and strain engineering approaches. The development of advanced processing modules, based on low temperature processing and deposited (MBE, ALD, epitaxially grown, etc.) gate stacks, has triggered the interest of exploring Ge for sub 32 nm technology nodes. A comparison between Si and Ge for future microelectronics has to take into account a variety of materials, processing and performance aspects. Here special attention will be given to passivation and gate stack formation in relation to device performance, including leakage current and reliability aspects. The potential of Ge-based device structures and the monolithic integration of Ge and III–V devices on silicon are highlighted.