Self-assembled Ni nanodot on SiO2 film: a novel reactive ion etching mask for Si nanopillar formation on Si substrate

By rapid thermal annealing the Ni film evaporated on thin SiO2 layer covered Si substrate, we have successfully demonstrated the self-aggregation of two-dimensional randomized Ni nano-dots on Si wafer. The thin oxide layer prevents the formation of NiSi2 compounds and facilitates the self-assembly of Ni nanodots from retaining the thermal power on SiO2 layer. This greatly shrinks the annealing time required for metallic nanodot formation from >10 min to <30 sec. With the advantage of the self-assemble Ni/SiO2 nano-dots based nano-mask, a large-area Si nano-pillar array with rod size of <50 nm can be formatted on Si substrate through the induced coupled plasma reactive ion etching (ICP-RIE) procedure. After removing Ni dots and the SiO2 film on the Si substrate, both the visible and near infrared photoluminescence from the Si nano-pillar sample were observed and analyzed.