THE EFFECTS OF GRAIN-SIZE GRADIENTS ON THE STABILITY OF THIN-FILMS

The morphological (shape) stability of thin films is of importance to a number of industries which rely on two-dimensional microstructural components. The structural breakup of thin films due to capillary shape instabilities at moderate temperatures where surface or interface diffusion is significant is an important technological concern. Many thin films produced by sputter deposition or high supersaturation chemical or physical vapor deposition have a small grain size and therefore high driving forces for grain growth. The purpose of this note is to consider the effect a non-homogeneous grain size distribution, as might result from abnormal grain growth, has on the morphological stability of thin polycrystalline films. The theoretical results are applied to a polycrystalline Au-Pd thin film grown by sputter deposition onto an electron transparent amorphous carbon substrate and heated in-situ in a hot stage at 600 degree C for 5 minutes. 3 Refs.