AVS 66th International Symposium & Exhibition
    Advanced Ion Microscopy and Ion Beam Nano-engineering Focus Topic Thursday Sessions
       Session HI-ThP

Paper HI-ThP2
Morphology Modification of Si Nanopillars under Ion Irradiation at Elevated Temperatures

Thursday, October 24, 2019, 6:30 pm, Room Union Station B

Session: Advanced Ion Microscopy Poster Session
Presenter: Xiaomo Xu, Helmholtz Zentrum Dresden-Rossendorf, Germany
Authors: X. Xu, Helmholtz Zentrum Dresden-Rossendorf, Germany
K.-H. Heinig, Helmholtz Zentrum Dresden-Rossendorf, Germany
W. Möller, Helmholtz-Zentrum Dresden-Rossendorf, Germany
H.-J. Engelmann, Helmholtz Zentrum Dresden-Rossendorf, Germany
N. Klingner, Helmholtz Zentrum Dresden-Rossendorf, Germany
A. Gharbi, CEA-LETI, France
R. Tiron, CEA-LETI, France
J. von Borany, Helmholtz Zentrum Dresden-Rossendorf, Germany
G. Hlawacek, Helmholtz-Zentrum Dresden Rossendorf, Germany
Correspondent: Click to Email
Ion beam irradiation of vertical nanopillar structures can be utilized to fabricate a vertical gate-all-around (GAA) single electron transistor (SET) device in a CMOS-compatible way. After irradiation of Si nanopillars (with a diameter of 35 nm and a height of 70 nm) by either 50 keV broad beam Si+ or 25 keV focused Ne+ beam from a helium ion microscope (HIM) at room temperature and a fluence of 2e16 ions/cm2, strong deformation of the nanopillars has been observed which hinders further device integration. This is attributed to ion beam induced amorphization of Si allowing plastic flow due to the ion hammering effect, which, in connection with surface capillary forces, dictates the final shape. However, plastic deformation can be suppressed under irradiation at elevated temperatures (investigated up to 672 K). Then, as confirmed by bright-field transmission electron microscopy, the substrate and the nanopillars remain crystalline, and are continuously thinned radially with increasing fluence down to a diameter of 10 nm. This is attributed to enhanced forward sputtering through the sidewalls of the pillar, and found in reasonable quantitative agreement with the predictions from 3D ballistic computer simulation using the TRI3DYN program.

This work is supported by the European Union’s H-2020 research project ‘IONS4SET’ under Grant Agreement No. 688072.