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.
Bibliographical noteFunding Information:
Financial support in the form of a “Brain Korea 21” fellowship provided by Ministry of Education, Korea is gratefully acknowledged.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)