Simulation of growth dynamics in atomic layer deposition. Part II. Polycrystalline films from cubic crystallites

The growth dynamics of polycrystalline thin films by the atomic layer deposition (ALD) technique has been simulated for randomly oriented and randomly positioned seed objects. Cubic crystals with the shape of cubes, octahedra, and truncated cubes have been used to exemplify the dynamics of polycrystalline growth of films with columnar structures. We have reproduced the non-linear growth in the initial stages of ALD preparation of polycrystalline films according to type-2 substrate-inhibited growth. The dependences of topography roughness, surface object density, and selection of angles on terminating surfaces on the film thickness are demonstrated. The topography and cross sections of the simulated films are also shown for the different crystal shapes considered. Means to control the topography to obtain either smooth or rough films are discussed. A possible reduction of surface roughness by the use of different types of precursors is exemplified for growth of crystal objects combining cube and octahedron shapes.