Effect of nitrogen plasma on the surface of indium oxide nanowires

Abstract

The change in the atomic nitrogen concentration on a semiconducting nanowire’s surface and the consequent changes in the electrical characteristics of a nanowire transistor were investigated by exposing In2O3 nanowires to nitrogen (N2) plasma. After plasma was applied at N2 flow rates of 20, 40, and 70 sccm with a fixed source power of 50 W, the In2O3 nanowire transistor exhibited changes in the threshold voltage (Vth), subthreshold slope (SS), and on-current (Ion). In particular, after treatment at an N2 flow rate of 40 sccm, Vth shifted positively by ∼2.3 V, the SS improved by ∼0.24 V/dec, and Ion increased by ∼0.8 μA on average. The changes are attributed to the combination of nitrogen ions produced by the plasma with oxygen vacancies or indium interstitials on the nanowires. Optimization of the plasma treatment conditions is expected to yield desirable device characteristics by a simple, nondestructive process.