FIELD-EMISSION CHARACTERISTICS OF POLYCRYSTALLINE AND SINGLE-CRYSTALLINE DIAMOND GROWN ON SI TIPS

Polycrystalline and single-crystal diamond coatings were grown on sili con field emitters by the hot filament CVD technique. The emission pro perties of both kinds of diamond coating were compared. Field emission from tips with a polycrystalline coating followed the Fowler-Nordheim emission law, and were characterized by a high maximum current (up to 500 mu A) and good emission stability. The single-crystal coating dem onstrated two emission modes: ''hysteresis'' and ''normal'' ones. In t he ''hysteresis'' mode, the emission current saturated at about 2 mu A . The transformation from ''hysteresis'' to ''normal'' behavior occurr ed with an increase of the voltage. Some possible emission mechanisms of diamond coated emitters are discussed.