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Abstract. Ge nanoparticles (NPs) embedded silicon oxide is expected to be promising light emission source, especially, UV -blue light region. We have tried to form Ge NPs in a 100-nm-thick SiO 2 layer on Si substrate by multi-energy implantation of Ge negative ions with energies of 50, 20 and 10 keV and doses of 1.4 x 10 16 , 3.2 x 10 15 and 2.2 x 10 15 ions/cm 2 , respectively. Samples were annealed for 1 h at a temperature less than 900 o C. By this implantation, Formations of Ge nanoparticles in a surface 50-nm depth region were expected. The depth distribution of implanted Ge atoms in the oxide was measured by XPS (Ge 2p, O 1s, Si 2p) with monochromatic Al K and Ar etching at 4 keV. The depth profiles were well agreed with the cross-sectional TEM image. But some extent of Ge atoms diffused to the SiO 2 /Si interface at 900 o C. The chemical sifted spectra of Ge 2p3/2 showed about 60 % of the oxidation of Ge atom around the end of the range (EOR) even in the as-implanted sample. This oxidation was considered to be due to the excess oxygen atoms near EOR by forward of sputtered oxygen atoms from SiO 2 layer. Raman spectra supported this oxidation. In a preliminary investigation of cathode luminescence, the Ge-implanted sample with annealing at 600 o C showed CL peak at 3.12 eV (397 nm in wavelength) in UV-blue region at room temperature. This means the Ge-implanted sample has a possibility for light emission in the UV-blue region.

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