Tuning of Surface Properties of AlGaN/GaN Sensors for Nanodroplets and Picodroplets

Modifications of AlGaN surfaces have been carried out in order to tune their wetting properties. A hydrophilic surface is achieved by a wet and dry thermal oxidation, whereas the deposition of fluorocarbon (FC) layers leads to a passivation with a hydrophobic behavior. It was found that both surfaces still change their properties in the first days/hours after the modification. For the FC layers, differences are observed in dependence of the deposition method, which are explained by the different chemical-bond structures of the various FC films