A Self-Assembled High Current Si Field Emitter Array

A simple, low-cost fabrication technology to develop high packing density arrays of silicon nano-field-emitters based on top-down self-assembly is presented. Using Langmuir-Blodgett deposition technique, a packed monolayer of silica particles with an average diameter of 200 nm is deposited on a patterned Si substrate. Silica particles act as micro-masks during deep reactive ion etching of the silicon wafer. Length, diameter, and sharpness of the nano-field-emitters are optimized by adjusting etching conditions to achieve high current density, low turn-on voltage, and reliable performance. Field-emitter density of
$1.6\times 10^{9}$
tips/cm
²
with a maximum measured current density of 13.1 A/cm
²
, corresponding to 8 nA/tip has been achieved. The average electric field for this measurement was as low as 3.5 V/μm.