Growth and Morphology of Magnetron-Sputtered TiAl Alloy Thin Films Studied by Atomic Force Microscopy

At the aim of investigating the growth mechanism and morphology evolution of magnetron-sputtered TiAl alloy thin films, we observe the films deposited for different times and find out the variation by atomic force microscopy. Nucleation mechanism and growth kinetics are studied by dynamic scaling, obtained from the morphology evolution of as-deposited TiAl thin films with different growth times. As a result, we demonstrate that the process of film growth goes through three stages, divided by three different growth exponents. The three growth exponents are β₁=0.52±0.01, β₂=0.71±0.01, and β₃=0.17±0.02, respectively. With the deposition time varying from 2 min to 10 min, the roughness exponent α fluctuates in the range 0.61–1.16.