SYNTHESIS OF GE NANOCRYSTALS IN THERMAL SIO2-FILMS BY GE-IMPLANTATION( ION)

Ge-nanocrystal-embedded SiO2 films were fabricated by Ge+ implantation into SiO2 films thermally grown on crystalline Si wafers, and were ex amined by Fourier transform infrared absorption spectroscopy, Raman sp ectroscopy, and X-ray photoemission spectroscopy. Due to Ge+ ion impla ntation, the SiO2 film moved off stoichiometry, and there were Ge oxid es formed in it. The precipitation and growth of Ge nanocrystals (nc-G e) were found to be related to some thermodynamical reductions of the Ge oxides during annealing. The average size of nc-Ge increases from s imilar to 3 nm to similar to 6 nm when the annealing temperature incre ase's from 400 degrees C to 1100 degrees C. (C) 1998 Published by Else vier Science S.A. All rights reserved.