• Pierson, Jean-François
• Melo, Claudia De
• Soldera, Flavio
• Rigoni, Federica
• Horwat, David
• Ghanbaja, Jaafar
• Vomiero, Alberto
• Almqvist, Nils
• Mücklich, Frank
• Montaigne, François
• Jullien, Maud

Abstract

Area-selective atomic layer deposition (AS-ALD) has attracted much attention in recent years due to the possibility of achieving accurate patterns in nanoscale features which render this technique compatible with the continuous downscaling in nanoelectronic devices. The growth selectivity is achieved by starting from different materials and results (ideally) in localized growth of a single material. We propose here a new concept, more subtle and general, in which a property of the substrate is modulated to achieve localized growth of different materials. This concept is demonstrated by selective growth of high quality metallic Cu, and semiconducting Cu2O thin films achieved by changing the type of majority point defects in the ZnO underneath film exposed to the reactive species using a patterned bi-layer structure composed of highly conductive and highly resistive areas, as confirmed by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). The selective growth of these materials in a patterned ZnO/Al-doped ZnO substrate allows the fabrication of p-Cu2O/n-ZnO nano-junctions showing a non-linear rectifying behavior typical of a p-n junction, as confirmed by conductive atomic force microscopy (C-AFM). This process expands the spectra of materials that can be grown in a selective manner by ALD and opens up the possibility of fabricating different architectures taking advantage of the area-selective deposition. This offers variety of opportunities in the field of transparent electronics, catalysis and photovoltaics.

Topics

• impedance spectroscopy
• thin film
• atomic force microscopy
• reactive
• transmission electron microscopy
• electron energy loss spectroscopy
• atomic layer deposition
• point defect