A facile route to Si nanowire gate-all-around field effect transistors with a steep subthreshold slope.

ABSTRACT

We present a facile CMOS-compatible fabrication of lateral gate-all-around (GAA) field effect transistors (FETs) based on concentric Si-SiO2/N(++)Si core-multi-shell nanowires (NWs). Si-SiO2/N(++)Si core-multi-shell NWs were prepared by sequential Si NW growth, thermal oxidation and Si deposition processes in a single chamber. The GAA NW FET was then fabricated using the Si core, SiO2 inner-shell, N(++) Si outer-shell as a channel, gate dielectric, and gate electrode, respectively. A one-step wet etching process was able to define the gate and source-drain contact regions. The SiNW GAA FET clearly exhibits a geometry-dependent gating effect and a steep subthreshold slope due to the low interface trapped charge density at the interface of the Si core and the SiO2 shell. Our proposed SiNW GAA structures offer new opportunities for low-energy-consumption digital device applications.