Influence of Interfaces on Crystal Growth of Si in SiO2/a-Si/SiO2 Layered Structures

The crystal growth of Si in SiO2/a-Si/SiO2 layered structures is examined by high resolution transmission electron microscopy. In a thin a-Si layer (10 nm), crystal growth halts with the crystallite size roughly equal to the layer thickness. In a thick layer (50 nm), crystal growth continues beyond the layer thickness. An expression for this halt in growth is derived from the free energy change. The halt in growth of Si crystallites suggests that the a-Si/SiO2 interface and the a-Si/c-Si interface are more stable than the c-Si/SiO2 interface.