Effect of surface roughness on field emission from chemical vapor deposited polycrystalline diamond

The effect of surface roughness on electron emission from hydrogenated poly crystalline diamond films is reported. Field emission measurements were per formed with both millimeter and nanometer spatial resolution using scanning probe techniques. Surface asperities were removed by ion beam treatment, w hich resulted in a reduction of the rms roughness from 198 to 94 nm, leadin g to an increase in the threshold field required for electron emission by a bout a factor of 2. These results suggest that surface asperities, rather t han grain boundaries, are the dominant influence on electron emission in po lycrystalline diamond films. (C) 2001 American Institute of Physics.