Rapid self-assembly of Ni nanodots on Si substrate covered by a less-adhesive and heat-accumulated SiO2 layers

Rapid self-aggregation of Ni nanodots on Si substrate covered with a thin SiO2 buffered layer is investigated. The Ni nanodots can hardly self-aggregate on highly heat-dissipated Si substrate with a thermal conductivity of 148W∕mK. Adding a 200-Å-thick SiO2 buffer with an ultralow thermal conductivity of 1.35W∕mK prevents the formation of NiSi2 compounds, enhances the heat accumulation, and releases the adhesion at Ni∕Si interface, which greatly accelerates the self-assembly of Ni nanodots. Dense Ni nanodots with size and density of 30nm and 7×1010cm−2, respectively, can be formatted after rapid thermal annealing at 850°C for 22s.