High-k/Ge MOSFETs for future nanoelectronics

Recently developed high-permittivity (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 nanoscale 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.