Fabrication and electrical characterization of high aspect ratio silicon field emitter arrays

Abstract

Micromachined high aspect ratio field emitter areas have been realized to obtain stabile and uniform emission current. Dry etching based on gas chopping method was used to etch the 42-μm-high ultra-sharp emitter tips in single-crystal silicon. Diamond-like carbon (DLC) films of 25–100 nm thickness were deposited from hydrocarbon precursor gas on the Si tips applying inductively coupled plasma enhanced chemical vapor deposition (ICPECVD) technique. Partial stabilization of emission current versus time due to oxygen or nitrogen plasma treatment could be related to surface passivation and/or formation of stable DLC/nanolayer on the emitter surface. It has been shown that DLC-coated emitters provide a comparable good long-term emission stability—the emission current did almost not decrease during a 46 h operation cycle. Summarizing we can say that high aspect ratio field emitter areas seem to have favorable field emission properties in respect to long-term stability.