Applied Physics Letters · 2015 · 200 citations · 15 references
EngineeringElectrical EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsDevice CharacterizationIii-v SemiconductorsSemiconductor Device MaterialsSemiconductor PhysicsWide Band Gap SemiconductorsWide-bandgap SemiconductorsAnalytical ModelsAvalanche BreakdownAvalanche Breakdown In Wide-bandgap DevicesBreakdown VoltageDifferential ResistanceForward Bias CharacteristicsJunction Ideality FactorP-n Junction Characteristics
Textbook-like device characteristics are demonstrated in vertical GaN p-n diodes grown on bulk GaN substrates. These devices show simultaneously an avalanche breakdown voltage (BV) of >1.4 kV under reverse bias, an ideality factor plateau of ∼2.0 in a forward bias window followed by a near unity ideality factor of 1.1, which are consistently achieved over a temperature range of 300–400 K. At room temperature (RT), the diode with a mesa diameter of 107 μm showed a differential on-resistance Ron of 0.12 mΩcm2, thus resulting in a record figure-of-merit BV2/Ron of ∼16.5 GW/cm2, which is the highest ever demonstrated in any semiconductors. Analytical models are used to fit experimental I-Vs; based on the recombination current with an ideality factor of ∼2.0, a Shockley-Read-Hall lifetime of 12 ns is extracted at RT with an estimated recombination center concentration of 3 × 1015 cm−3.
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