Effects of O-2, H-2, and N-2 gases on the field emission properties of diamond-coated microtips

We report the effects of O-2, H-2, and N-2 residual gases on the field emis sion properties of uncoated and diamond-coated individual Mo microtips. The microtips are made using electrochemical etching techniques and positioned 5 mu m from the anode using a scanning tunneling microscopy system. We obs erve that the field emission (FE) current and turn-on voltage of diamond-co ated microtips are significantly less degraded by O-2 exposure than those o f uncoated Mo microtips. H-2 exposure enhances the FE properties of both un coated and diamond-coated microtips, while N-2 exposure does not have any s ignificant effect. (C) 1999 American Institute of Physics. [S0003-6951(99)0 2734-5].