Surface modifications of AlGaN/GaN sensors for water based nano- and picodroplets [chemical and biosensors]

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