Carbon nitride (CNx) films with 0-22.8 at. % N were prepared using dual ion
beam deposition With increasing N content in this range, more N-containing
pyridinelike rings, and single, double, and triple bends between C and N w
ere formed, resulting in polymerization of the film structure. Consequently
, the films became more transparent in the infrared region, and the hardnes
s dropped from 24.2 to 12 GPa. Furthermore, nanoscratch tests showed that l
ess debris was produced along the scratch track on the film containing high
N content, indicating that the film was less brittle following the polymer
ization of the film structure. in addition, the minimum (critical) normal l
oad for damaging the films dropped from 7.8 to 4 mN, reflecting that the ad
hesion between the firms and substrates was weakened, thereby resulting in
delamination of the films from the substrates. Finally, the room temperatur
e electrical conductivity was found to be reduced by a factor of 100, consi
stent with the more pronounced polymerlike nature of the films at high N co
ntents. (C) 1999 American Vacuum Society: [S0734-2101(99)03902-0].