Atomic force microscopy study of surface roughening of sputter-deposited TiN thin films

The kinetic surface roughening of TiN thin films sputter-deposited on silicon substrates at room temperature was studied. Scaling analyses were made by surface measurements of atomic force microscopy (AFM). The roughness exponent α and growth exponent β that characterize scaling behaviors of surface growth were calculated using the height-height correlation function H(r) and power spectra P(f). The exponent values of α=∼0.98 and β=∼0.28 indicated that the surface growth behavior of sputtered TiN thin films could be adequately explained by a simple linear growth model showing surface diffusion as a smoothing effect and shot noise as a roughening mechanism. An inverse Fourier transformation technique was also used to generate the evolution of theoretical surface profiles that showed good agreement with AFM measurements.