FABRICATION OF NANOCRYSTALLINE SILICON SUPERLATTICES BY CONTROLLED THERMAL RECRYSTALLIZATION

We report the fabrication of nanocrystalline Si superlattices by plasm a-assisted chemical vapor deposition (PECVD) or magnetron sputtering o f nanometer-thick amorphous Si (a-Si) layers followed by high-temperat ure recrystallization. The recrystallization is performed in two steps (rapid thermal pulse annealing and slow ramp-up furnace annealing) an d has been monitored by Raman scattering. The fabrication technique is able to control the size and packing density of Si nanocrystals in th e nc-Si/SiO2 superlattices. Preliminary results on the doping of Si na nocrystals are discussed. Room temperature photoluminescence with a qu antum efficiency of 0.3% is demonstrated.