Fabrication of uniform Ge-nanocrystals embedded in amorphous SiO_2 films using Ge-ion implantation and neutron irradiation methods

摘要

Uniform Ge-nanocrystals (Ge-ncs) embedded in amorphous SiO_2 film were formed by using 74Ge+ ion implantation and neutron transmutation doping (NTD) method. Both experimental and theoretical results indicate that the existence of As dopants transmuted from ~(74)Ge by NTD tunes the already stabilized (crystallized) system back to a metastable state and then activates the mass transfer processes during the transition form this metastable state back to the stable (crystallized) state, and hence the nanocrystal size uniformity and higher volume density of Ge-ncs. This method has the potential to open a route in the three-dimensional nanofabrication.