Freiburg engineers Kittitat Subannajui, Firat Güder and Margit Zacharias have reported their latest results in the journal Nanotechnology. The method begins by using phase shift lithography to produce nanopolymer dots at desired positions on the wafer. The substrate containing the nanopolymer dots is etched to give nano pinholes, which act as a nanowire mold for atomic layer deposition (ALD). It transforms the former silicon nanowires by ALD into ZnO nanowires resulting in an ordered array of polycrystalline ZnO nanowires vertically arranged on the silicon wafer.

Current nanowire technology uses chemical vapour deposition (CVD) methods, which have an operational temperature above 700 °C. The operational temperature of ALD is in the range 110–150 °C, which is better suited for integration with micro-system technology.

The new method is said to be very flexible because it is not limited to the fabrication of ZnO nanowires. Operators can produce nanowires from any material that can be deposited by ALD into the nanopores.

More information can be found in the journal Nanotechnology.