Kinetic model of stress evolution during coalescence and growth of polycrystalline thin films.

We outline a simple continuum model of the stresses that result from the coalescence and growth of islands during deposition of a polycrystalline thin film. Our model includes a detailed description of attractive forces between neighboring islands, and also accounts for mass transport along surfaces and grain boundaries. The finite element method is used to calculate the island shape changes as well as the stresses and displacements in the film during the growth process. The model reproduces several experimental observations, including the variation of stress with film thickness, the range of observed growth stresses, and the effects of deposition flux and grain boundary diffusivity on stress.