Three-dimensional composition mapping of NiSi phase distribution and Pt diffusion via grain boundaries in Ni2Si

The formation of Ni silicide alloyed with Pt has been analyzed by atom probe tomography. A 300 °C/1 h anneal results in simultaneous growth of the NiSi and Ni2Si phases: the Ni2Si phase is a continuous layer with columnar grains, while the NiSi phase forms a discontinuous layer. Direct evidence of Pt diffusion short-circuits via Ni2Si grain boundaries is shown. The presence of Pt in the grains and interphase boundaries may explain the change in the Ni silicide formation for the Ni(5% Pt)/Si system.