Evaluation Model of Emitter Roughness Impact Responsible for Diamond Based Cold Emitter IV Characteristics Aberration

Abstract

Nanostructured diamond films deposited in microwave (MW) plasma enhanced chemical vapor deposition (CVD) process were evaluated as a potential material for cold emitters in autoemission microdiode and microtriode. Graphite-diamond composite film was chosen for further evaluation after initial feasibility study with unpatterned films. Autoemission currents were detected even at normal conditions without vacuum. Measured IV microdiode and microtriode characteristics showed certain aberration from linearity when plotted with Fowler-Northeim coordinates. A model based on consideration of gradual activation of emitting centers is proposed. Emitter surface roughness plays essential role and it is believed to be have the most sufficient impact on Fowler-Northeim IV curves linearity distortion.