Applied Physics Letters · 2003 · 98 citations · 12 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsSemiconductor Device MaterialsSemiconductor InterfacesSemiconductor PhysicsSemiconductor SurfacesSurface PassivationSurface PhysicsBarrier HeightsHydrogen PassivationInterfacial OxidesLeakageSchottky Barrier DiodesSchottky ContactsSemiconductor Surface PreparationStructural Defects
The hydrogen response of Pd:GaN Schottky diodes, prepared by in situ and ex situ deposition of catalytic Pd Schottky contacts on Si-doped GaN layers is compared. Ex situ fabricated devices show a sensitivity towards molecular hydrogen, which is about 50 times higher than for in situ deposited diodes. From the analysis of these results, we conclude that adsorption sites for atomic hydrogen in Pd:GaN sensors are provided by an oxidic intermediate layer. In addition, in situ deposited Pd Schottky contacts reveal lower barrier heights and drastically higher reverse currents. We suggest that the passivation of the GaN surface before ex situ deposition of Pd also results in quenching of leakage paths caused by structural defects.
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A hydrogen−sensitive MOS field−effect transistor
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Hydrogen response mechanism of Pt–GaN Schottky diodes
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Gas sensitive GaN/AlGaN-heterostructures
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