NANOCRYSTALLINE SILICON SUPERLATTICES - FABRICATION AND CHARACTERIZATION

Rapid thermal annealing of amorphous Si/SiO2 superlattices deposited b y rf-sputtering and plasma oxidation forms Si nanocrystals while maint aining the superlattice structure. The crystal size is controlled by t he thickness of the Si sublayers and can be varied from 12 nm to simil ar to 2.5 nm. The strain in the c-Si/SiO2 structure is released by ann ealing at 1050 degrees C using a slow temperature ramp. After wet oxid ation which reduces the size and completes the passivation of the crys tals by SiO2, the room-temperature band-edge photoluminescence reaches an external quantum efficiency > 0.1%. (C) 1998 Elsevier Science B.V. All rights reserved.