2006 · 66 citations · 2 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesSemiconductor MaterialsDevice CharacterizationDevice ScalingMetal-oxide-semiconductor Field-effect TransistorsSemiconductor Device MaterialsWide-bandgap Semiconductor DevicesWide-bandgap SemiconductorsChannel DopingCurrent DensityDevice Scaling EffectsPower MosfetsSilicon Carbide Power DevicesSilicon Carbide Power ElectronicsThermal Oxidation
In this paper, we report 4H-SiC power DMOSFETs capable of blocking 10 kV. The devices were scaled up to 5 A, which is a factor of 25 increase in device area compared to the previously reported value. The devices utilized 100 μm thick n-type epilayers with a doping concentration of 6 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> for drift layers, and a floating guard ring based edge termination structure was used. The gate oxide layer was formed by thermal oxidation at 1175°C, followed by an NO anneal. A peak effective channel mobility of 13 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /Vs was extracted from a test MOSFET with a W/L of 150 μm / 150 μm, built adjacent to the power DMOSFETs. A 4H-SiC DMOSFET with an active area of 0.15 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> showed a specific on-resistance of 111 mΩ-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at room temperature with a gate bias of 15 V. The device shows a leakage current of 3.3 μA, which corresponds to a leakage current density of 11 μA-cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> at a drain bias of 10 kV.
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