Luminescence in Multilayers of SiGe Nanocrystals Embedded in SiO2

ABSTRACTLuminescent multilayers of SiGe nanocrystals embedded in an oxide matrix have been fabricated by Low Pressure Chemical Vapour Deposition of a-SiGe and SiO2 in a single run followed by a Rapid Thermal Annealing treatment. The diameter of the nanoparticles, the oxide interlayer thickness and the annealing conditions have been investigated in order to get the maximum intensity of the luminescence. The structures with small nanoparticles (3-4.5 nm) separated by thick oxide barriers (≈35 nm) annealed at 900 °C for 60 s yield the maximum intensity. These samples exhibit luminescence from 80 K to room temperature. An additional treatment at 450 °C in forming gas further increases the intensity of this luminescence.