Analytical model for island growth in atomic layer deposition using geometrical principles

摘要

Island growth has been shown to also occur for atomic layer deposition (ALD) processes. This article presents a relatively simple analytical model using geometrical principles with few independent variables on evolution of thickness and roughness in island-dominated ALD processes. The model is well suited for the fitting of experimental data to extract parameters such as density of islands and growth rate. It allows islands of various shapes, but most of the attention here is devoted to cone and hemispherical shaped islands in a hexagonal grid on a flat substrate. For a selection of cases, exact analytical expressions are derived. The model shows that it is possible to reproduce the growth characteristics of substrate-inhibited growth of both types 1 and 2 with a suitable choice of functional form of the islands. Finally it is compared with previously advanced models describing substrate-inhibited growth.