Modeling of Morphological Changes by Surface Diffusion in Silicon Trenches

We present a three - Dimensional model of surface diffusion which describes the time evolution and topography changes of deep trenches under low pressure hydrogen anneal and compare the results with experimental observations. A phase diagram for regular arranged cylindrical trenches was derived by using a genetic optimization algorithm. Seven different structural phases of the final bubble / layer arrangement out of the trench array anneal could be predicted. The impact of perturbations in the regular trench array is discussed too and the change in the phase diagram - shrinkage of the stable region for single top layer formation - is calculated .