Size control of Si nanocrystals by two-step rapid thermal annealing of sputtered Si-rich oxide/SiO2 superlattice

Abstract

Controllable size of silicon (Si) nanocrystals can be achieved by a two-step rapid thermal annealing technique consisting of rapid annealing at 1000°C in nitrogen ambient and rapid oxidation at 600–800°C of a radio frequency magnetron co-sputtered Si-rich oxide/SiO2 superlattice structure. The photoluminescence (PL) spectra related to Si nanocrystals were observed in the visible range (600–900 nm). After rapid oxidation, the size of the nanocrystals was reduced and the quality of the Si nanocrystal/SiO2 interface was improved, resulting in a blue shift and an increase of the PL peak intensity. Finally, annealing in air increases the PL intensity further.