Rice University graduate students and researchers have made nanowires between 6 and 16 nanometers wide. The wires are made from a variety of materials, including silicon, silicon dioxide, gold, chromium, tungsten, titanium, titanium dioxide, and aluminum. The development of sub-10-nanometer sizes shows promise for the semiconductor industry as it continuously seeks to make smaller circuits.
The researchers discovered that the meniscus – the curvy surface of water at its edge – can be an effective mask to make nanowire patterns. The water molecules gather wherever a raised pattern joins the target material, and forms a curved meniscus created by the surface tension of water.
The meniscus-mask process involves adding and then removing materials in a sequence that ultimately leaves a meniscus covering the wire and climbing the sidewall of a sacrificial metal mask that, when etched away, leaves the nanowire standing alone.
According to the researchers, the process should work with modern fabrication technology. No tools, materials, or modifications to existing equipment are required.