Applied Physics Letters · 2021 · 21 citations · 17 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsDopingP-n JunctionsSemiconductor DefectsSemiconductor Device MaterialsSemiconductor HeterostructuresSemiconductor PhysicsAvalanche BreakdownBreakdown MechanismsCurrent DensityJunction BreakdownJunction Leakage CurrentLeakageLeakage CurrentTrap Levels
We demonstrate that theoretical breakdown fields can be realized in practically dislocation free Al-rich AlGaN p-n junctions grown on AlN single crystal substrates. Furthermore, we also demonstrate a leakage current density in AlGaN that is independent of the device area, indicating a bulk leakage phenomenon and not surface or mesa-edge related. Accordingly, we identified the Poole–Frenkel emission from two types of point-defect traps in AlGaN as the primary source of reverse leakage before breakdown. Mg-doped AlGaN exhibited leakage currents due to a shallow trap at ∼0.16 eV in contrast with leakage currents observed in Si-doped AlGaN due to a deep trap at ∼1.8 eV.
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