Electron field emission from surface treated tetrahedral amorphous carbon films

The electron field emission properties of tetrahedral amorphous carbon thin films deposited using a filtered cathodic vacuum arc system have improved as a result of surface treatment with H, O, and Ar ions. The limiting facto r of the emission process does not appear to be only the front surface of t he films. The improvement in the emission after ion beam treatment appears to be independent of the ions used. The surface which has been analyzed usi ng ultraviolet photospectroscopy, reflected electron energy loss spectrosco py, and scanning tunneling microscopy shows evidence of the creation of seg regated sp(2) and sp(3) rich regions of less than 20 nm in dimension. An ex tension to the space charge-induced band bending model including a multiste p emission process that occurs in this mixed phase material is proposed. (C ) 1999 American Institute of Physics. [S0003-6951(99)02304-9].