PHOTOLUMINESCENCE FROM NANOMETER GE PARTICLE EMBEDDED SI OXIDE-FILMS

Nanometer Ge particle (NGP) embedded Si oxide films were deposited on p-type Si substrates using the rf magnetron sputtering technique with a Ge-SiO2 composite target. The area ratio percentage of the Ge target to the composite target was 5%. These films were annealed in a N-2 am bient at 300, 600, 800, or 900 degrees C for 30 min. By fitting Raman scattering spectra, the average diameters of,the NGPs in the films wer e determined. They increased from 5.4 to 9.5 nm with increasing anneal ing temperatures from 600 to 900 degrees C. The photoluminescence (PL) peaks for all NGP embedded Si oxide films annealed at various tempera tures are located at almost the same position around 580 nm (2.1. eV), although the average sizes of the NGPs in these films are very differ ent from each other. After gamma-ray irradiation, the PL peak intensit y increases by a factor of 2.3, with the peak position unchanged. The PL peak position does not show any evident shift when the measurement temperature increases from 10 to 300 K. All experimental facts indicat e that Light emission originates mainly from the luminescence centers in the SiOx films covering the NGPs rather than from the NGPs. The rol e of NGPs in the PL process of the films is discussed. (C) 1998 Americ an Institute of Physics.