FABRICATION AND CHARACTERIZATION OF DIAMOND-CLAD SILICON FIELD EMITTER ARRAYS

Microsized silicon tip arrays with sharp curvature were formed based o n the techniques including reactive ion etching and oxidation-sbarpeni ng. A new fabrication technology of polycrystalline diamond-clad Si mi crotips using microwave plasma CVD(MPCVD) was subsequently developed t o improve the capability and stability of tile field emission from til e pure Si tips. By means of SEM and transmission electron microscopy ( TEM), the as-deposited films are found to be polycrystalline diamond w ith fine grain (similar to 800 Angstrom) structure. With tile anode vo ltage of 1100V and anode-to-cathode distance of 30 mu m, the emission current of 240 mu A in a 50 x 50 diamond-clad Si microtip array can be achieved, which is much higher than those for Cr-clad and pure Si mic rotip arrays. Based on curve fitting of a Fowler-Nordheim (F-N) plot, such great improvement is partially attributed to the lowering of the effective work function from 5.5 eV to 2.08 eV.