We have studied surface roughness scaling of ZnO:Al thin films grown by rf magnetron sputtering of a compound target within framework of the dynamic scaling theory using atomic force microscopy. We have observed a crossover in scaling behavior of surface roughness at a deposition time of 25 min. Both the regimes are characterized by power-law dependence of local surface width w (r,t) on deposition time for small r, typical of anomalous scaling. The scaling exponents for the first regime indicate the existence of a new dynamics. For t25 min, the films follow super-rough scaling behavior with global exponents α=1.5±0.2 and Β=1.03±0.01, and local exponents αlocal =1 and Βlocal =0.67±0.05. The anomaly in the scaling behavior of the films is discussed in terms of the shadowing instability and bombardment of energetic particles during growth of the films.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)