Metal Organic Chemical Vapor Deposition of nickel oxide thin films for wide band gap device technology

Epitaxial nickel oxide (NiO) thin films have been grown by Metal Organic Chemical Vapor Deposition on AlGaN/GaN heterostructures. Critical growth parameters have been studied in order to optimize the deposition process of NiO films suitable for applications in GaN-based devices. In particular, a second generation precursor has been used as nickel source, namely the N,N,N',N'-tetramethylethylenediamine adduct of nickel bis 2-thenoyltrifluoroacetonate, using different deposition temperatures and oxygen flow values. Optimized operative conditions allowed the growth of epitaxial thin films which exhibited a permittivity of 11.7, close to the bulk value. The electrical characterization of the obtained epitaxial films pointed out to promising dielectric properties for AlGaN/GaN transistor technology.