Effect of back contact on field emission from carbon films deposited by very high frequency chemical vapor deposition

Abstract

The effect of material and surface morphology of the back contact on field emission has been studied in carbon films deposited by very high frequency chemical vapor deposition at low temperature. The emission current was measured as a function of applied field for carbon films deposited simultaneously on various substrates coated with metals having different work functions ͑Ti, Cu, Ni, and Pt͒. Different metals demonstrated different types of microstructure and surface morphology. Therefore, the effect of back contact morphology was especially studied. The material of the back contact influenced the emission properties, but no direct correlation between emission and the work function of metal was observed. The field emission threshold was found to be affected by the roughness of the back contact: a Ti contact with 270 nm roughness showed emission threshold of E th ϭ3 V/m, while a contact made of the same material, but with roughness of ϳ2.5 nm had E th ϭ13 V/m.

Effect of Metal Back Contacts on Tetrahedral Amorphous Carbonc Films Grown Using the Cathodic Arc Process.

“…A detailed report on this will be presented else were. Recently Koserev et.al [23] have reported the effect of back contact on field emission from carbon films grown using very high frequency chemical vapour deposition at low temperature. They observed that there is no direct correlation between the contact metal work function and the emission current.…”