Characterization of metal-induced lateral crystallization of amorphous SiGe on insulating film

Ni metal-induced lateral crystallization (Ni-MILC) of amorphous Si0.6Ge0.4 thin films has been investigated by means of scanning electron microscopy and transmission electron microscopy. A pattern of Ni about 5 nm thick was fabricated to cover selective areas of the a-Si0.6Ge0.4 film. Subsequently, the thin film was annealed at 550 °C for various lengths of time. In the area covered with Ni, Ni atoms diffuse into the SiGe film and react with Ge to produce precipitates of Ni2Ge, leaving amorphous Si. In the area outside of the Ni-covered one, on the other hand, crystallization occurs to form aggregates of small Si0.6Ge0.4 grains without Ni incorporation. In the MILC process, the kind of Ni compound phase changes with the amount of diffusing Ni and the lateral crystallization should be induced by the formation of NiSi2.