Germanium nanoparticles formed in silicon dioxide layer by multi-energy implantation and oxidation state of Ge atoms

Abstract

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.

Ion beam induced surface and interface engineering

“…At each age of research, ion implantation has become attractive for world wide researchers because of its applicability in various fields such as LSI (Large Scale Integration) device fabrication, powder surface modification, nanoparticle formation in insulators for quantum devices, catalysis and LE (light emitting) devices, and biocompatibility control for nerve cell patterning and nervous system repair [41][42][43][44][45][46][47][48][49].…”

Formation and Characterization of Ultra-Sensitive Surface Plasmon Resonance Sensor Based Upon a Nano-Scale Corrugated Multi-Layered Coated D-Shaped Optical Fiber

“…The details of the production of the surface relief modulation, which occurs in the coating during UV light exposure, is still under investigation, however it is known that UV light incident on Ge/GeO 2 produces photo-bleaching and compaction of the material [14]. Several publications have reported photo-induced structural changes in glasses doped with germanium or composite materials containing germanium when illuminated with UV light [16,17]. We envisage that spatially periodic UV illumination of the Ge and SiO 2 layers in our device produces a surface corrugation due to this compaction.…”