CVD of copper and copper oxide thin films via the in situ reduction of copper(ii) nitrate—a route to conformal superhydrophobic coatings

The use of copper organometallics is an established route to generate thin films of copper. This paper describes the deposition of copper and copper(I) oxide films using relatively inexpensive copper nitrate solutions in a facile aerosol assisted chemical vapour deposition process. The composition of the resultant thin film was dependant on the solvent used and temperature of deposition, with evidence to suggest an in situ production of hydrogen which protects the copper films from oxidation. The metallic copper films were subsequently modified by oxidation to copper hydroxide and functionalised with a fluorinated thiol. The treated films were extremely hydrophobic with water contact angles that approached 180° and a less than 1° tilt angle, this a product of the extremely rough and low energy surface. The conformal substrate coverage achieved with this technique could be implemented for uniform metallic, semiconductor, hydrophilic or superhydrophobic coatings.