N-type Schottky barrier source/drain MOSFET using Ytterbium silicide

Abstract

Ytterbium silicide, for the first time, was used to form the Schottky barrier source/drain (S/D) of N-channel MOSFETs. The device fabrication was performed at low temperature, wich is highly preferred in the establishment of Schottky barrier S/D transistor (SSDT) technology, including the HfO2 gate dielectric, and HaN/TaN metal gate. The YbSi2-x silicided N-SSDT has demonstrated a very promising characteristic with a recorded high Ion/Ioff ratio of ∼107 and a steep subthreshold slope of 75 mV/dec, which is attributed to the lower electron barrier height and better film morphology of the YbSi2-x/Si contact compared with other self-aligned rare earth metal-(Erbium, Terbium, Dysprosium) silicided Schottky junctions. © 2004 IEEE.