Dynamics of surface evolution in semiconductor thin films grown from a chemical bath

Dynamics of surface evolution in CdS thin films grown by chemical bath deposition technique has been studied from time sequence of atomic force micrographs. Detailed scaling analysis of surface fluctuation in real and Fourier space yielded characteristic exponents α(loc) = 0.78 ± 0.07, α = 2.20 ± 0.08, α(s) = 1.49 ± 0.22, β = 0.86 ± 0.05 and β(loc) = 0.43 ± 0.10, which are very different from those predicted by the local growth models and are not related to any known universality classes. The observed anomalous scaling pattern, characterized by power law scaling dependence of interface width on deposition time differently at local and global scale, with rapid roughening of the growth front has been discussed to arise as a consequence of a nonlocal effect in the form of diffusional instability.