Effects of thermal annealing on the microstructure and mechanical properties of carbon-nitrogen films deposited by radio frequency-magnetron sputtering
Mm. Lacerda et al., Effects of thermal annealing on the microstructure and mechanical properties of carbon-nitrogen films deposited by radio frequency-magnetron sputtering, J VAC SCI A, 17(5), 1999, pp. 2811-2818
Amorphous carbon-nitrogen films deposited by radio frequency-magnetron sput
tering were annealed in vacuum for 30 min at temperatures between 300 and 7
00 degrees C, without any kind of sequential annealing. The annealing-induc
ed modifications on the chemical composition of the films were followed by
ion beam analysis (IBA). Raman scattering and infrared absorption spectrosc
opies were used to determine the microstructure modifications, while atomic
force microscopy (AFM) was used to investigate the surface morphology. The
internal stress of the films was obtained by measuring the bending of the
substrate and the nanoindentation technique was used to measure the film ha
rdness. Besides the nitrogen loss, determined by IBA analyses, Raman result
s suggested an increase in the size or in the number of the graphitic domai
ns with the annealing temperature. AFM shows a decrease of the surface roug
hness as a function of the annealing temperature. The density, the hardness
, and the internal stress of the films present a similar dependence on the
annealing temperature, i.e., they increase with the temperature of the ther
mal treatment. The thermal treatment induces,a structural modification on t
he carbon-nitrogen films changing from a Soft paracyanogen-like material to
a harder and more graphitic one. (C) 1999 American Vacuum Society. [S0734-
2101(99)03405-3].