Inclusions in Si whiskers grown by Ni metal induced lateral crystallization

The formation of Nickel-di-silicide inclusions in silicon whiskers grown during low temperature Ni Metal Induced Lateral Crystallization of amorphous Silicon was studied by High Resolution Transmission Electron Microscopy, Scanning Transmission Electron Microscopy, and Electron Energy Loss Spectroscopy. The heat treatment of the samples lasted for 11 + 11 days at 413 °C for the first 11 days and 442 °C for the rest of the time. The size of the inclusions ranges from just a few atoms to 15-20 nm. It was shown that the NiSi₂ inclusions have the form of tetrahedrons, which are bound by {111} coherent interfaces with the Si matrix. These inclusions are homogeneously distributed along the whiskers, and the Ni percentage incorporated in these is 0.035 at. %. The tetrahedral inclusions are formed by trapping NiSi₂ clusters at the Si/NiSi₂ interface during whisker growth.