On the Formation of 50 nm Diameter Free-Standing Silicon WiresProduced by Ion Irradiation

Ion irradiation in conjunction with electrochemical etching is a promising silicon (Si) machining technique for three-dimensional nanofabrication. We present a study of factors influencing the formation of silicon nanowires fabricated by this technique, such as ion energy, fluence, proximity of adjacent wires, location within an irradiated area and wafer resistivity. A better understanding of these factors in different resistivity wafers has enabled us to produce wire diameters and gaps between adjacent wires of about 50 nm using 50 keV protons. Multilayer silicon nanowire arrays are also achieved, so extending the use of this process for three dimensional nanoscale silicon machining.