Japanese Journal of Applied Physics · 2022 · 11 citations · 25 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsInterface ScienceSemiconductor MaterialsInterface EngineeringMos CapacitorsSemiconductor Device MaterialsSemiconductor InterfacesSemiconductor SurfacesSurface PhysicsCapacitance-voltage CharacteristicsCapacitance-voltage CharacterizationCapacitance-voltage MeasurementsCapacitance-voltage ProfilingCapacitorsElectrical PropertiesNitridationUltraviolet Light Treatment
Abstract Nitridation of SiO 2 /4H-SiC(112̄0) interfaces with post-oxidation annealing in an NO ambient (NO-POA) and its impact on the electrical properties were investigated. Sub-nm-resolution nitrogen depth profiling at the interfaces was conducted by using a scanning X-ray photoelectron spectroscopy microprobe. The results showed that nitrogen atoms were incorporated just at the interface and that interface nitridation proceeded much faster than at SiO 2 /SiC(0001) interfaces, resulting in a 2.3 times higher nitrogen concentration. Electrical characterizations of metal-oxide-semiconductor capacitors were conducted through capacitance–voltage ( C – V ) measurements in the dark and under illumination with ultraviolet light to evaluate the interface defects near the conduction and valence band edges and those causing hysteresis and shifting of the C – V curves. While all of these defects were passivated with the progress of the interface nitridation, excessive nitridation resulted in degradation of the MOS capacitors. The optimal conditions for NO-POA are discussed on the basis of these experimental findings.
25