X-ray Investigations on CoSi2 nano wires manufactured by focused ion beam synthesis


X-ray Investigations on CoSi2 nano wires manufactured by focused ion beam synthesis

Grenzer, J.; Biermanns, A.; Akhmadaliev, C.; Bischoff, L.

Nano wires and chains of nano particles are of emerging interest in nanoelectronics, nano-optics and plasmonics as well as for their monolithic integration into microelectronic devices; CoSi2 is a promising material due to its CMOS-compatibility that shows metallic behavior with low resistivity and high thermal stability. It is well known that cobalt disilicide films can be formed in silicon by implanting Co in stoichiometric concentration and a subsequent annealing procedure. It has been shown that ion beam synthesis allows the fabrication of epitaxial buried or surface CoSi2 layers on silicon. Submicron patterns can be directly produced by a writing focused ion beam (FIB) cobalt implantation. The formation of continuous nano wire structures follows always the <110> direction [1].
We have studied the strain of the Si host lattice in the surrounding area of a single nanostructures depending on their crystallographic orientation using high resolution X-ray diffraction in combination with a highly focused (~1µm) X-ray beam at the beam line ID01 at the ESRF. The crystalline nano wire is embedded into the Si matrix and shows a tensile strain of about 1.4%. This feature can be only found if the beam focused on the nano wire itself. We will show that it is possible to investigate a single nano wire of a size of below 50 nm. The CoSi2 peak intensity is strongly modulated if we move from one wire to an other. Moreover the diffuse scattered intensity around the Si bulk reflection is increased and is getting even more enhanced between the wires (see Figure 1). A possible mechanism, the formation of stable dislocation loops, lying behind the formation of CoSi2 wires will be discussed.

[1] Ch. Akhmadaliev, B. Schmidt and L. Bischoff, Appl. Phys. Lett. 89, 223129 (2006); Ch. Akhmadaliev, L. Bischoff and B. Schmidt; Mat. Sci. & Eng., C26, 818 (2006).

Keywords: Nanostrukturen; focused x-ray beams

  • Lecture (Conference)
    Science with X-ray Nano-beams, 09.-12.02.2010, Grenoble, Frankreich
  • Poster
    10th Biennial Conference on High Resolution X-Ray Diffraction and Imaging, 20.09.2010, Warwick, England

Permalink: https://www.hzdr.de/publications/Publ-14920
Publ.-Id: 14920