Deutsche Tagung f ¨ur Forschung mit ... - SNI-Portal

Nanostrukturen und Grenzflächen Poster: Do., 13:00–15:30 D-P281
X-ray study of ion-induced surface ripples in Si
Souren Grigorian 1 , Joerg Grenzer 2 , Andreas Biermanns 1 , Ullrich Pietsch 1 ,
Milan Sanyal 3 , Tapas Chini 3 , Satyajit Hazra 3
1 Institute of Physics, University of Siegen,Walter Flex 3, 57078 Siegen, Germany –
2 Institute of Ion Beam Physics and Materials Research,Bautzner Landstrasse 128,
D-01328 Dresden, Germany – 3 Surface Physics Division, Saha Institute of Nuclear
Physics, 1/AF Bidhannagar, Kolkata 700 064, India
Nanopattering at the metal and semiconductor surfaces by ion-beam irradiation has
attracted significant technological interest due to possibility for the fabrication of novel
nanodevices [1,2]. Recently has been shown, that structural features of the irradiated
Si crystals and, especially, crystalline ripples can be studied at the 3rd generation synchrotron
radiation sources [3]. In particular, the near-surface ripples pattern can be
characterized by depth resolved x-ray grazing incidence diffraction (GID). The GID
intensity profiles show the presence of satellite peaks on both sides of the main (220)
Bragg peak. The appearance of satellite peaks confirms the existence of lateral undulation
of the buried crystalline part of the sample. Additionally to the crystalline part, the
amorphization process is very important to understand an amorphous-crystalline interfacial
and a ripple formation mechanism. Amorphization features depending on the
irradiation dose were probed by means of x-ray grazing amorphous scattering (GIAS).
Two broad peaks of the GIAS profiles indicate short-range ordering of amorphous material
of the irradiated samples. GIAS profiles taken under different azimuthal angles
display a strong anisotropy of the amorphous scattering. A strong damage of crystalline
structures takes place along particular crystallographic directions at low doses
of irradiation. A complete, mostly uniform amorphization is eminent at high doses of
irradiation. This mechanism can be used for a better understanding of the formation
of subsurface amorphous-crystalline ripples.
We would like to thank ID beamline staff for the support at ESRF. This work was
supported by the DST-DAAD India-Germany Collaborative Program.
[1] T. Aste and U. Valbusa, New Journal of Physics 7 (2005) 122.
[2] C.Hofer, S. Abermann, C. Teichert, T. Bobek, H. Kurz, K. Lyutovich, E. Kasper
Nuc. Inst. and Meth. in Phys. Res. B. 216 (2004) 178.
[3] S. Hazra, T. K. Chini, and M. K. Sanyal, Grenzer J and Pietsch U Phys. Rev. B
70 (2004) 121307.