Effect of rapid thermal annealing on Si rich SiO2 films prepared using atom beam sputtering technique

We report here the synthesis of silicon-nanoclusters embedded in SiO2 by atom beam co-sputtering technique. A sputtering target consisted of 40% and 60% area of Si pieces glued on a fused silica plate. A co-sputtered film containing Si embedded in SiO2 having different compositional fractions of Si was deposited on fused silica and c-Si substrates. Annealing was done in N2 atmosphere for 1 min at temperatures ranging from 700–900 °C to precipitate silicon nanoclusters. Samples were characterized using Raman and FTIR spectroscopy. In IR absorption spectra, the blue shift of the Si–O–Si asymmetric stretching band, from 1017 cm− 1 for as-deposited samples, to 1070 cm− 1 for samples annealed at 900 °C, indicates that phase separation of Si and SiO2 has been completed and films consist of Si particles embedded in an SiO2 matrix. Raman spectrum showed the emergence of 513 cm− 1 due to nanocrystalline silicon after RTA at 900 °C.