Growth mode transition of Ni thin films on nanopatterned substrate: Kinetic Monte Carlo simulations

A three-dimension (3D) kinetic Monte Carlo (KMC) model with Ehrlich–Schwoebel barrier is presented. A uniform arranged triangular prism structure is introduced to mimic the nanopatterned substrate. The transition from continuous growth to anisotropic columnar growth has been demonstrated. The kinetic process and the growth exponent are discussed by our KMC model. Results show that the growth exponent is smaller than 0.5 when the film thickness surpasses 70 ML under normal deposition but larger than 0.5 under high oblique angle deposition, such as 77°. We assume that the modulation of nanopatterned substrate reduces more quickly when the film thickness is larger than 70 ML in our model. The growth mode transition can be mainly attributed to difference in the relative importance of diffusion and shadowing with normal and high oblique angle deposition conditions. Besides, the competition and vanishing process during oblique angle deposition are also demonstrated.