Field emitters with carbon containing coverages and based on carbon fibers: possibilities of creation and use in microwave electronics

Abstract

High chemical inertness of carbon materials and their stability upon ion bombardment makes them attractive for vacuum microwave devices. However, high work function of carbon, as well as technological difficulties of pure coverage and ordered structure formation prevent the creation of carbon field emitters, Only few investigations are known where attempts to create emission sources made of carbon or carbon containing coverages were performed. The present work deals with field emitters covered with molecules of C/sub 60/ and emitters made from carbon fibers. The results showed that the regularities of carbon containing coverage formation by means of fullerene molecule adsorption. The expediency to form a distributed structure consisting of the small microcluster was shown to give stable emission under acceptable voltages. The possibility to create a single tip emitter covered by carbon was discovered. Such an emitter with micron diameter secured a current of more than 100 /spl mu/A under the operating voltage /spl sim/15 kV in static regime. The nonordered multi-tip field emitter based on carbon fiber was also realized.