Applied Physics Express · 2019 · 39 citations · 29 references
Natural SciencesMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor MaterialsThin FilmsAmorphous SemiconductorsDielectricsOxide SemiconductorsSemiconductor PhysicsThin Film Electrical PropertiesWide Band Gap SemiconductorsAmorphous StructureCapacitorsConduction BandFlatband VoltageGallium Nitride (Gan) MaterialsGate Dielectric EngineeringGate DielectricsHigh-dielectric-constant Materials
Characteristics of hafnium silicate as gate dielectric in n-GaN capacitors were investigated. The Hf0.57Si0.43Ox, Hf0.64Si0.36Ox and HfO2 films exhibited high dielectric constants of 15.4, 15.9, and 17.6, respectively. The Hf0.57Si0.43Ox and Hf0.64Si0.36Ox films, which had an amorphous structure, showed superior properties, including a minimal flatband voltage (Vfb) hysteresis (≤70 mV) and a small Vfb shift (≤−0.45 V), as well as a low interface state density (~4 × 1011 cm−2 eV−1 at −0.4 eV from conduction band), and a high breakdown electric field (≥8.6 MV cm−1) compared to those of a polycrystalline HfO2 film.
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