Silicon nanowires as enhancement-mode Schottky barrier field-effect transistors

Silicon nanowire field-effect transistors (SiNWFETs) have been fabricated with a highly simplified integration scheme to function as Schottky barrier transistors with excellent enhancement-mode characteristics and a high on/off current ratio ∼107. SiNWFETs show significant improvement in the thermal emission leakage (∼6 × 10−13 A µm−1) compared to reference FETs with a larger channel width (∼7 × 10−10 A µm−1). The drain current level depends substantially on the contact metal work function as determined by examining devices with different source/drain contacts of Ti (≈4.33 eV) and Cr (≈4.50 eV). The different conduction mechanisms for accumulation- and inversion-mode operation are discussed and compared with two-dimensional numerical simulation results.