Self-Assembled Ni Nanodot on SiO_2 Film—A Novel Reactive Ion Etching Mask for Si Nanopillar Formation on Si Substrate

摘要

By rapid thermal annealing the Ni film evaporated on thin SiO_2 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 NiSi_2 compounds and facilitates the self-assembly of Ni nanodots from retaining the thermal power on SiO_2 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/SiO_2 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 SiO_2 film on the Si substrate, both the visible and near infrared photoluminescence from the Si nano-pillar sample were observed and analyzed.