Effect of nitrogen doping on field emission characteristics of patterned diamond-like carbon films prepared by pulsed laser deposition

Effect of nitrogen doping on field emission characteristics of patterned diamond-like carbon (DLC) films was studied. The patterned DLC films were fabricated by the method reported previously [I. H. Shin and T. D. Lee, J. Vac. Sci. Technol. B 17, 690 (1999)]. Nitrogen doping in the DLC film was carried out by introducing N-2 gas into the vacuum chamber during deposition. Level of doping was controlled by varying N-2 flow rate up to 50 seem. Nitrogen content in the films almost linearly increased with increasing N-2 flow rate. Higher emission current density of 0.3-0.4 mA/cm(2) was observed for the films with 6 at. % N than the undoped films, but the emission current density decreased with further increase of N contents. Some changes in CN bonding characteristics with increasing N contents were observed. The CN bonding characteristics which seem to affect the electron emission properties of these films were studied by Raman spectroscopy, x-ray photoemission spectroscopy and Fourier transform infrared spectroscopy. Electrical resistivity and optical band gap measurements showed consistence with the above analysis. (C) 2000 American Vacuum Society. [S0734-211X(00)04902-7].