Fabrication of nanostructure arrays by ion beam irradiation

Periodic semiconductor nanostructure arrays have the potential for nano-electronic and nano-optoelectronic application. The broad ion beam erosion is a simple and potentially mass productive technique to fabricate the nanostructure patterns on semiconductor surface as it avoids conventional lithographic steps.[1] The present work reports the fabrication of horizontal silicon nanowire arrays on insulator by Xe+ ion beam erosion of Si-on-insulator substrate. [3] A periodic ripple surface pattern of the Si surface is created by irradiation with Xe+ ions and the transfer of this pattern to the oxide interface as shown in figure 1a. This procedure results in an array of disconnected parallel ordered Si nanowires. A more recent achievement concerns nanopattern of single crystal Ge substrate which is based on a “negative epitaxy”. Vacancies created during ion beam sputtering will diffuse and rearrange according to the crystallographic anisotropy of the substrate which results in orientation-dependent pattern formation of the Ge surface.
Figure 1 (a) Schematic of Si NWs array fabricated by Xe+ beam irradiation on Si-on-insulator substrate. (b)Atomic Froce Miroscopy (AFM) images showing the nanostructure and pattern fabricated on Ge (100) and Ge (111) surface based on “negative epitaxy” process. The scale is 100 nm
[1] S. Facsko et al. Science 285, (1999) 1551.
[2] C. S. Madi et al. Physical Review Letters, 106, (2011) 066101.
[3] X. Ou et al. AIP Advances, 1, (2011) 042174.