Influence of a transient hexagonal phase on the microstructure and morphological stability of NiSi films

The morphological stability of NiSi is investigated when 40% of Si is mixed into an as deposited 10 nm Ni film. When annealing at 3 °C/s, scanning electron microscopy images and in situ sheet-resistance measurements show that NiSi agglomeration is delayed by more than 100 °C. In situ x-ray diffraction reveals that NiSi grows from an unusual transient hexagonal θ-nickel-silicide phase. The significant improvement of the NiSi film’s morphological stability can be related to its microstructure, with large grains and a strong texture. This peculiar microstructure is compared to the microstructure of the θ-nickel-silicide precursor by electron backscattering diffraction and pole figures.