Silicon nanocrystal formation upon annealing of SiO2 layers implanted with Si ions

Autor: Vladimir A. Volodin, M. O. Ruault, V. G. Kesler, A. F. Leier, S. G. Yanovskaya, G. A. Kachurin
Přispěvatelé: Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Rok vydání: 2002
Předmět:
Zdroj: Semiconductors
Semiconductors, 2002, 36, pp.647-651
ISSN: 1090-6479
1063-7826
DOI: 10.1134/1.1485663
Popis: The formation of silicon nanocrystals in SiO2 layers implanted with Si ions was investigated by Raman scattering, X-ray photoelectron spectroscopy, and photoluminescence. The excess Si concentration was varied between 3 and 14 at. %. It was found that Si clusters are formed immediately after implantation. As the temperature of the subsequent annealing was raised, the segregation of Si accompanied by the formation of Si-Si4 bonds was enhanced but the scattering by clusters was reduced. This effect is attributed to the transformation of loosely packed clusters into compact, separate-phase nanoscale Si precipitates, with the Raman peak observed at 490 cm−1 being related to surface scattering. The process of Si segregation was completed at 1000°C. Nevertheless, characteristic nanocrystal photoluminescence was observed only after annealing at 1100°C. Simultaneously, scattering in the range 495–520 cm−1, typical of nanocrystals, appeared; however, the “surface-related” peak at 490 cm−1 persisted. It is argued that nanocrystals are composed of an inside region and a surface layer, which is responsible for their increased formation temperature.
Databáze: OpenAIRE