An advanced fabrication method of highly ordered ZnO nanowire arrays on silicon substrates by atomic layer deposition

Abstract

In this work, the controlled fabrication of highly ordered ZnO nanowire (NW) arrays on silicon substrates is reported. Si NWs fabricated by a combination of phase shift lithography and etching are used as a template and are subsequently substituted by ZnO NWs with a dry etching technique and atomic layer deposition. This fabrication technique allows the vertical ZnO NWs to be fabricated on 4in Si wafers. Room temperature photoluminescence and micro-photoluminescence are used to observe the optical properties of the atomic layer deposition (ALD) based ZnO NWs. The sharp UV luminescence observed from the ALD ZnO NWs is unexpected for the polycrystalline nanostructure. Surprisingly, the defect related luminescence is much decreased compared to an ALD ZnO film deposited at the same time on a plane substrate. Electrical characterization was carried out by using nanomanipulators. With the p-type Si substrate and the n-type ZnO NWs the nanodevices represent pn NW diodes. The nanowire diodes show a very high breakthrough potential which implies that the ALD ZnO NWs can be used for future electronic applications. © 2012 IOP Publishing Ltd.