Fabrication and Characterization of Axially Doped Silicon Nanowire Tunnel Field-Effect Transistors

Tunnel field-effect transistors were fabricated from axially doped silicon nanowire p-n junctions grown via the vapor liquid solid method Following dry thermal oxidation to form a gate dielectric shell, the nanowires have a p n n(+) doping profile with an abrupt n-n(+) junction which was revealed by scanning capacitance microscopy The lightly doped n segment can be inverted to p(+) by modulating the top gate bias thus forming an abrupt gated p(+)-n(+) junction A band to band tunneling current flows through the electrostatically doped p(+) n(+) junction when It is reverse biased Current voltage measurements performed from 375 down to 4 2 K show two different regimes of tunneling current at high and low temperatures indicating that there are both direct band to band and trap-assisted tunneling paths