Electroluminescent device based on silicon nanopillars

Silicon nanopillars were fabricated by using deep UV lithography, highly anisotropic silicon reactive ion etching based on fluorine chemistry, and high-temperature thermal oxidation for further thinning. Pillars with a diameter below 10 nm and a height in the 0.4-0.6 mu m range were obtained while lying on a very smooth bottom silicon surface. An isolating transparent polymer was then used to fill in the etched area containing the pillars and, therefore, planarize and isolate the pillars, Oxygen plasma was used in order to remove the resistance from the top of the pillars, They were then contacted by a thin contact layer (gold or indium tin oxide), evaporated on the top of them, An Ohmic contact was also formed on the back side of the wafer. The obtained device showed rectifying behavior and forward voltages exceeding 10-12 V electroluminescence was observed, visible with the naked eye. (C) 1996 American Institute of Physics.