High-k/Ge MOSFETs for future nanoelectronics

Recently developed high-permittttivity [k] materials have reopened the door to Ge as a channel material in metal-oxide-semiconductor field-effect transistors [MOSFETs]. High-k/Ge gate stacks are very promising for future nanscale devices. This article reviews the opportunities and challenges of high-k/Ge MOSFET technology. The most important technical issue is the passivation of the Ge surface. Physical phenomena and electrical characteristics that depend on the high-k/Ge interface are discussed on the basis of the material properties of Ge oxide to provide insights for future progress.