Enhancement on field-emission characteristics of diamondlike coated Mo substrates by redox process

We have improved the emission characteristic of diamondlike carbon (DLC)-co ated Mo substrates by using a reduction-oxidation (redox) process. The maxi mum emission current density of the DLC/Mo films increased substantially fr om 10 to 225 muA/cm(2) with the turn-on field decreased from 12.4 to 6.4 V/ mum due to redox treatment. Secondary-ion mass spectrometry spectra and x-r ay diffraction patterns show that the structure of Mo films was insignifica ntly changed due to oxidation and reduction, whereas atomic force microscop y and transmission electron microscopy indicate that the roughness increase d markedly. The electron emission characteristics of DLC films coated on re dox Mo substrates are much better than those of the films coated on normal Mo film, which is ascribed to the increase in the field enhancement factor of the DC films. (C) 2001 American Vacuum Society.