AVS 52nd International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP30
Local Nanodeposition of Oxides with Focused Beams - Improving Material and Interface Quality

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Surface Science Poster Session
Presenter: M. Fischer, Vienna University of Technology, Austria
Authors: H.D. Wanzenboeck, Vienna University of Technology, Austria
M. Fischer, Vienna University of Technology, Austria
S. Mueller, Vienna University of Technology, Austria
J. Gottsbacher, Vienna University of Technology, Austria
W. Brezna, Vienna University of Technology, Austria
M. Schramboeck, Vienna University of Technology, Austria
A. Tomastik, Vienna University of Technology, Austria
H. Stoerti, Vienna University of Technology, Austria
H. Hutter, Vienna University of Technology, Austria
E. Bertagnolli, Vienna University of Technology, Austria
Correspondent: Click to Email
The fabrication of silicon oxide by direct-write deposition with a focused beam is an advanced nano-engineering technique. This locally confined chemical vapour deposition is a versatile tool for tailored surface modification. Two alternative methods - deposition with a focused ion beam (FIB) and a focused electron beam (FEB) - are compared. A silicon precursor such as siloxane is adsorbed on the surface and decomposed by the energy of the focused electron or ion beam. The chemical and physical phenomena at the oxide surface were investigated experimentally and by simulation of the energy dissipation of the incident beam. The process stage adsorption, surface diffusion, surface reactions, and layer growth are discussed. This work demonstrates the capability of this maskless method to fabricate arbitrary geometries of oxide and to create real 3-dimensional nanostructures. The material qualities of silicon oxide surfaces obtained with both methods are compared by chemical analysis, vibrational spectroscopy, optical and electrical characterisation. The beneficial addition of oxygen is reported and the optimum process window is identified. The chemical composition and the topography of the oxide surface are investigated by Auger electron spectroscopy (AES) and atomic force microscopy (AFM). A correlation between process parameters and the surface properties was found. The interface between the deposited microstructures is investigated by secondary ion mass spectroscopy (SIMS) and by electrical characterisation of capacitor devices with the deposited silicon oxide. Results indicate significant atomic mixing at the interface with FIB induced deposition, while a sharp interface can be obtained with the electron beam. This work contributes to a fundamental understanding of oxide formation on the nanoscale by beam induced deposition. This emerging maskless nanotechnique promises applications in MEMS, optical microstructures and dielectrics for semiconductor devices.