Field emission from tetrahedral amorphous carbon as a function of surface treatment and substrate material

To understand the mechanism of electron field emission from diamond-like ca rbon, tetrahedral amorphous carbon (ta-C) films were subjected to Ar, H-2, and O-2 plasma treatments to change their surface condition and were deposi ted on substrates of different work function. The threshold fields and curr ent densities for undoped ta-C are found to be significantly improved by th e plasma treatments, largely due to an increase in emission site density, w hile little dependence was found on work function of substrate. This sugges ts that the main barrier to emission from ta-C is at the front surface. (C) 1999 American Institute of Physics. [S0003-6951(99)01811-2].