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Title: Ion Beam Etching: Replication of Micro Nano-structured 3D Stencil Masks

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.3120093· OSTI ID:21289591
; ;  [1]; ;  [2]
  1. Institute for Microtechnologies, Swiss University for Applied Sciences HE-Arc, Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland)
  2. Microsystems Laboratory LMIS1, EPFL, Bm 3.116, Station 17, CH-1015 Lausanne (Switzerland)

Ion beam LIGA allows the etching of 3D nano-structures by direct writing with a nano-sized beam. However, this is a relatively time consuming process. We propose here another approach for etching structures on large surfaces and faster, compared to the direct writing process. This approach consists of replicating 3D structured masks, by scanning an unfocused ion beam. A polymer substrate is placed behind the mask, as in UV photolithography. But the main advantage is that the 3D structure of the mask can be replicated into the polymer. For that purpose, the masks (developped at LMIS1, EPFL) are made of a silicon nitride membrane 100 nm thick, on which 3D gold structures up to 200 nm thick, are deposited. The 3D Au structures are made with the nanostencil method, based on successive gold deposition. The IMA institute, from HE-Arc, owns a High Voltage Engineering 1.7 MV Tandetron with both solid and gaseous negative ion sources, able to generate ions from almost every chemical element in a broad range of energies comprised between 400 keV and 6.8 MeV. The beam composition and energy are chosen in such a way, that ions lose a significant fraction of their energy when passing through the thickest regions of the mask. Ions passing through thinner regions of the mask loose a smaller fraction of their energy and etch the polymer with larger thicknesses, allowing a replication of the mask into the polymer. For our trials, we have used a carbon beam with an energy of 500 keV. The beam was focussed to a diameter of 5 mm with solid slits, in order to avoid border effects and thus ensure a homogeneous dose distribution on the beam diameter. The feasibility of this technique has been demonstrated, allowing industrial applications for micro-mould fabrication, micro-fluidics and micro-optics.

OSTI ID:
21289591
Journal Information:
AIP Conference Proceedings, Vol. 1099, Issue 1; Conference: CAARI 2008: 12. international conference on application of accelerators in research and industry, Fort Worth, TX (United States), 10-15 Aug 2008; Other Information: DOI: 10.1063/1.3120093; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English