Si-rich/SiO2 nanostructured multilayers by reactive magnetron sputtering

Silicon-rich (SR)/SiO2 multilayered systems were produced by reactive magne tron sputtering, through an approach based on the ability of hydrogen, when alternatively mixed to the argon of the plasma, to reduce the oxygen origi nated from the SiO2 target. Optimum values of both hydrogen partial pressur e (45 mTorr) and deposition temperature (500 degreesC) have led to the high est incorporation of Si in the SR layer which crystallizes after annealing. The SR/SiO2 superlattices grown with such conditions showed that the size of the Si nanocrystals is limited by the thickness of the SR layer. Conside ring the difference observed between the photoluminescence peak position an d the predicted band gap for Si nanocrystals, the results suggest that we d eal with a quantum-size confinement assisted by a Si-O vibration located at the interface. (C) 2001 American Institute of Physics.