Synthesis of nickel disilicide quantum dots in silicon dioxide films

Nickel disilicide (NiS2) quantum dots (QDs) have been grown in silicon-rich oxide (SiOx) films by either ion implanting with nickel or coating with an evaporated Ni film and annealing at 1100 °C. It is shown that both techniques produce well-defined single-crystal NiSi2 QDs embedded in a SiOx matrix. It is further shown that the QDs are approximately spherical in shape and that their size can be influenced by limiting the Ni concentration. For example, QDs are shown to have diameters in the range from 5 to 25 nm for an SiOx (x = 1.16) layer with Ni concentration of 0.1–10 at.%.