SiC-capped nanotip arrays for field emission with ultralow turn-on field

Silicon nanotips with tip diameter and height measuring 1 nm and 1 μm, respectively, and density in the range of ${10}^9{\text{–3×10}}^{11}\hspace{0.17em}{\mathrm{cm}}^{\text{−2}},$ were fabricated monolithically from silicon wafers by electron cyclotron resonance plasma etching technique at a temperature of $\text{200\hspace{0.05em}°}\mathrm{C}.$ Field emission current densities of $\text{3.0\hspace{0.17em}}{\mathrm{mA/cm}}^2$ at an applied field of $\text{∼1.0\hspace{0.17em}}\mathrm{V}\mathrm{/\mu }\mathrm{m}$ was obtained from these silicon nanotips. High-resolution transmission electron microscope and Auger electron spectroscopy analyses concluded that the nanotips are composed of monolithic silicon and nanometer-size SiC cap at the top. A 0.35 V/μm turn-on field to draw a $\text{10\hspace{0.17em}μ}{\mathrm{A/cm}}^2$ current density was demonstrated, which is much lower than other reported materials. The excellent field emission property demonstrated by these nanotips, which were fabricated by a process integrable to the existing silicon device technology at low temperatures, is a step forward in achieving low-power field emission displays and vacuum electronic devices.