Pulsed laser deposition of diamond-like carbon films on gated Si field emitter arrays for improved electron emission

Diamond-like carbon (DLC) films were deposited on niobium gated silicon fie ld emitter arrays to improve the emission properties. DLC deposition was ca rried out either ex-situ by conventional pulsed laser deposition in a separ ate chamber or in-situ during electron emission in a test chamber. Various process parameters such as the thickness of the DLC films and the ambient g as during bhn deposition were systematically varied. The thickness of the D LC coating was found to play a crucial role for the emission characteristic s of the FEA. An increase of bath the emission current and its stability co uld be achieved using thin DLC films up to 6 nm. Thicker films, on the othe r hand, caused a decrease in the emission current. The results could be exp lained by a metal-insulator-metal (MIM) model for the electron transport th rough the DLC film. An increase or decrease of the emission current was obs erved also for the in-situ deposited DLC films depending on: the gas enviro nment during the deposition process.