Top-down fabricated reconfigurable FET with two symmetric and high-current on-states

TL;DR

This paper presents a top-down fabricated reconfigurable FET based on silicon nanowires, demonstrating high symmetry, high on/off ratios, and superior current densities in both p- and n- configurations, with precise electrostatic control.

Contribution

The work introduces a novel top-down fabrication process for a reconfigurable FET with symmetric transfer characteristics and high performance, utilizing Schottky junctions and controlled stress.

Findings

High symmetry of transfer characteristics

High on/off current ratios in both configurations

Superior current densities compared to other top-down RFETs

Abstract

We demonstrate a top-down fabricated reconfigurable field effect transistor (RFET) based on a silicon nanowire that can be electrostatically programmed to p- and n-configuration. The device unites a high symmetry of transfer characteristics, high on/off current ratios in both configurations and superior current densities in comparison to other top-down fabricated RFETs. Two NiSi2/Si Schottky junctions are formed inside the wire and gated individually. The narrow omega-gated channel is fabricated by a repeated SiO2 etch and growth sequence and a conformal TiN deposition. The gate and Schottky contact metal work functions and the oxide-induced compressive stress to the Schottky junction are adjusted to result in only factor 1.6 higher p- than n-current for in absolute terms identical gate voltages and identical drain voltages.