Persistence in thin film growth on patterned substrates

Abstract

The purpose of high quality thin film growth on patterned substrates is to maintain the pattern during deposition process. A simulation growth model is used here to determine appropriate conditions in which the pattern can remain for a long time. Two noise reduction techniques, multiple hit and long surface diffusion length, are introduced into the original model. In this work, we find that the former technique, which works well in growth on flat substrates, is not good for patterned substrate growth. The latter, the longer surface diffusion length l in computer simulations, is equivalent to higher substrate temperature in experiments. We find that the pattern persists for longer period of time when l is increased. However, there is a limit to how large l can be. Finally, we suggest a new definition of persistence probability instead of the original one which is too strict and hence does not truly reflect what we observe in the morphology. Our studieslead to a conclusion that the long-lived persistence of the pattern depends on two factors: the smoothness of the flat part in the pattern and the outline shape of the pattern.