Charge transport modulation of silicon nanowire by O-2 plasma

Abstract

The modification of the electrical characteristics of field-effect transistors (FETs) with channels composed of n- or p-type silicon nanowires (SiNWs) by oxygen plasma treatment is investigated in this study. The SiNWs obtained from silicon bulk wafers are < 111 > surface-oriented and their doping concentrations are similar to 10(21) and similar to 10(17) cm(-3) for the n- and p-type SiNWs, respectively. After the back-gate SiNWFETs were subjected to oxygen plasma treatment, the magnitude of the drain current of the n-type SiNWs was decreased, whereas that of the p-type SiNWs was increased, while the gate-dependent characteristics of both of types of SiNWs were improved. The changes in the electrical characteristics are due to the adsorption of oxygen ions on the surface of the SiNWs. To verify the effect of the oxygen ions, the SiNWFETs were kept in a vacuum for 24 h whereupon their electrical characteristics tended to revert to their inherent state. (C) 2009 Elsevier Masson SAS. All rights reserved.