Structural changes in nickel silicide thin films under the presence of Al and Ga

Abstract

Thin Ni/Al and Ni/Ga layers of different atomic ratios were codeposited onto Si(001) at room temperature followed by subsequent annealing. Influence of annealing temperature on morphology and composition of ternary disilicide NiSi2-xAlx and NiSi2- xGax layers was investigated by transmission electron microscopy. Addition of Al or Ga leads to a decrease of the disilicide formation temperature from 700° C down to at least 500° C. Depending on the composition closed, uniformly oriented NiSi2-xAl x and NiSi2-xGax layers were observed after annealing at 900°C, whereas reaction of a pure Ni film with Si leads to the island formation with a mixture of A- and Btype orientations. © (2010) Trans Tech Publications.