Fabrication of silicon microstructures using a high-energy ion beam

Ee Jin Teo, Minghui Liu, Mark B. H. Breese, Emmanuel P. Tavernier, Andrew A. Bettiol, Daniel J. Blackwood, Frank Watt, Eric G. Johnson, Gregory P. Nordin
2004 Micromachining Technology for Micro-Optics and Nano-Optics II  
We report an alternative technique which utilizes fast proton or helium ion irradiation prior to electrochemical etching for three-dimensional micro-fabrication in bulk p-type silicon. The ion-induced damage increases the resistivity of the irradiated regions and slows down porous silicon formation. A raised structure of the scanned area is left behind after removal of the un-irradiated regions with potassium hydroxide. The thickness of the removed material depends on the irradiated dose at
more » ... region so that multiple level structures can be produced with a single irradiation step. By exposing the silicon to different ion energies, the implanted depth and hence structure height can be precisely varied. We demonstrate the versatility of this three-dimensional patterning process to create multilevel cross structure and freestanding bridges in bulk silicon, as well as sub-micron pillars and high aspect-ratio nano-tips.
doi:10.1117/12.524314 fatcat:ue2lo37p3bgx3gqn6sm4s3kn7e