Current Gain of 4H-SiC Bipolar Transistors Including the Effect of Interface States

Martin Domeij; Erik Danielsson; Hyung Seok Lee; Carl Mikael Zetterling; Mikael Östling

doi:10.4028/www.scientific.net/MSF.483-485.889

Paper Titles

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Effective Edge Termination Design in SiC VJFET
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Electrical Characteristics Temperature Dependence of 600V-Class Deep Implanted Gate Vertical JFET
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Gamma and Proton Irradiation Effects on 4H-SiC Depletion-Mode Trench JFETs
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Current Gain of 4H-SiC Bipolar Transistors Including the Effect of Interface States
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BV_CEO Versus BV_CBO for 4H and 6H Polytype SiC Bipolar Junction Transistors
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Electrical Characteristics of 4H-SiC BJTs at Elevated Temperatures
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1000 V, 30 A SiC Bipolar Junction Transistors and Integrated Darlington Pairs
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A 4H-SiC BJT with an Epitaxially Regrown Extrinsic Base Layer
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HomeMaterials Science ForumMaterials Science Forum Vols. 483-485Current Gain of 4H-SiC Bipolar Transistors...

Current Gain of 4H-SiC Bipolar Transistors Including the Effect of Interface States

Abstract:

The current gain (b) of 4H-SiC BJTs as function of collector current (IC) has been investigated by DC and pulsed measurements and by device simulations. A measured monotonic increase of b with IC agrees well with simulations using a constant distribution of interface states at the 4H-SiC/SiO2 interface along the etched side-wall of the base-emitter junction. Simulations using only bulk recombination, on the other hand, are in poor agreement with the measurements. The interface states degrade the simulated current gain by combined effects of localized recombination and trapped charge that influence the surface potential. Additionally, bandgap narrowing has a significant impact by reducing the peak current gain by about 50 % in simulations.