Applied Physics Letters · 2011 · 168 citations · 14 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsInterface ScienceSemiconductor MaterialsAluminum OxidesAtomic Layer DepositionSemiconductor InterfacesSemiconductor PhysicsWide Band Gap SemiconductorsWide-bandgap SemiconductorsCapacitance-voltage CharacteristicsCapacitance-voltage CharacterizationCapacitance-voltage MeasurementsConduction BandElectrical PropertiesFixed Charge DensityGallium NitrideInterfacial Charge Density
We report on our investigation of the electrical properties of metal/Al2O3/GaN metal-insulator-semiconductor capacitors. We determined the conduction band offset and interface charge density of the alumina/GaN interface by analyzing the capacitance-voltage characteristics of atomic layer deposited Al2O3 films on GaN substrates. The conduction band offset at the Al2O3/GaN interface was calculated to be 2.13 eV, in agreement with theoretical predications. A non-zero field of 0.93 MV/cm in the oxide under flat-band conditions in the GaN was inferred, which we attribute to a fixed net positive charge density of magnitude 4.60 × 1012 cm−2 at the Al2O3/GaN interface. We provide hypotheses to explain the origin of this charge by analyzing the energy band line-up.
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Z. H. Liu, Geok Ing Ng, S. Arulkumaran et al. · Applied Physics Letters · 2009 · 108 citations
Gate-First AlGaN/GaN HEMT Technology for High-Frequency Applications
Omair I. Saadat, J.W. Chung, E. L. Piner et al. · IEEE Electron Device Letters · 2009 · 101 citations · Full text