Spatial variation of field emission current on nitrogen-doped diamond-likecarbon surfaces by scanning probe method

Field emission characteristics of nitrogen-doped diamond-like carbon (DLC) films deposited by the radio frequency plasma enhanced chemical vapor depos ition (rf-PECVD) method were investigated by the scanning probe system spec ially designed for the micro-scale field emission current measurements. The structural changes in the films were examined by using Raman spectroscopy. Random and inhomogeneous distribution of electron emission sites was obser ved. The emission current and conductivity of the films were significantly increased with self-bias voltage. Activated electron emission characteristi cs were observed in all samples and showed stable electron emission. The ac tivation of the films was directly related to emission site size. It indica ted that electron emission activation possibly originated from the changes in sp(2) and sp(3) bonding ratio and/or formation of conductive channels. ( C) 2001 Elsevier Science B.V. All rights reserved.