Numerical study of the effective surface area of obliquely deposited thin films

We have developed a three-dimensional Monte Carlo simulator for thin film growth and applied it to understand the morphologies of thin films prepared by dynamic oblique deposition with a special emphasis on an effective surface area. Columnar shapes zigzag, helix, and cylinder are successfully reproduced, and the packing density of simulated thin films agrees quantitatively with that obtained experimentally. The effective surface area is enhanced by oblique deposition owing to columnar formation and becomes maximum at a deposition angle of 70 °. On the contrary, no significant dependence of the effective surface area on the columnar shapes has been observed. Consequently, morphology-related quantities of obliquely deposited thin films such as the packing density and the effective surface area are understood in terms of the deposition angle and are insensitive to the motion of the azimuthal deposition direction.