Edge-shaped diamond field emission arrays

Abstract

This article presents the fabrication, characterization, and field emission behavior of edge-shaped diamond field emission arrays. Edge-shaped field emitter geometry is advantageous in the pursuit of high emission current since each edge can have a continuous multiple emission site along the edge as determined by the microstructure of the edge surface. Thus in totality an edge emitter provides significantly larger emission area and hence has the potential for larger current or transconductance for field emission devices. The edge arrays were fabricated via a mold transfer technique on a silicon substrate utilizing silicon micropatterning and etching, followed by chemical-vapor deposited diamond deposition. Arrays of micropatterned edge-shaped diamond emitters were developed and tested for field emission. Moreover, field emission characteristics were improved by further sharpening the edge apex achieving a lower turn-on field and higher emission current. Edge sharpening was achieved by introducing a silicon oxidation step in the mold fabrication process before the diamond deposition step. This oxidation process not only sharpened the edge but also served as a gate dielectric for the development of a self-aligned gated triode device.