Effects of deposition temperature on the structure of amorphous carbon nitride films

Amorphous carbon nitride films (a-CNx) were deposited on Si(100) under different rf power and at different substrate temperature TS using rf magnetron sputtering of a high-purity graphite target in pure nitrogen. IR absorption, Raman spectra, and residual stress measurements are used to characterise the films in the as deposited state. The differences in the microstructure of the a-CNx films is related to differences in the deposition mechanism. The TS contribution can operate to increase the connectivity of the C–C network. The stress evolution is the result of the densification, i.e. a structural transformation within of the films that accompanies the nitrogen evolution, due to the C–N and C–C evolution when TS is increased.