Abstract

Layer-thickness dependence of Si-nanocrystal (Si-NC) formation induced by furnace annealing in amorphous Si (a-Si)/SiO₂ multilayers is experimentally demonstrated with a radio-frequency-sputtered sample that has a-Si layers with different thicknesses. Further, a modified model is developed to explain the Si-NC formation based on the Gibbs free energy variation and it takes into account the whole formation process including nucleation and following growth. The theoretical results show that there is a lower limit of Si layer thickness below which the crystal formation cannot occur for a-Si/SiO₂ multilayers, and the oxide interfaces cannot constrain the lateral growth of Si-NCs, which may lead to their touches within the Si layers.

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