Time Dependent Trapping and Generation-Recombination of Interface Charges: Modeling and Characterization for 4H-SiC MOSFETs

Siddharth Potbhare; Neil Goldsman; Gary Pennington; Aivars J. Lelis; J.M. McGarrity

doi:10.4028/www.scientific.net/MSF.556-557.847

Paper Titles

SiC Field Effect Transistor Technology Demonstrating Prolonged Stable Operation at 500 °C
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SiC MOSFET Channel Mobility Dependence on Substrate Doping and Temperature Considering High Density of Interface Traps
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Simulation Study of High-k Materials for SiC Trench MOSFETs
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Temperature Stability of Heteropolytypic 6H/3C FETs
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Time Dependent Trapping and Generation-Recombination of Interface Charges: Modeling and Characterization for 4H-SiC MOSFETs
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Reliability of SiC Power Devices Against Cosmic Radiation-Induced Failure
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600 V 100 A 4H-SiC Junction Barrier Schottky Diode with Guard Rings Termination
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Breakdown Voltage Characteristics of FLR-Assisted SiC-SBD Formed by Aluminum Metal Junction Edge Termination
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Comparison between Schottky Diodes with Oxide Ramp Termination on Silicon Carbide and Diamond
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HomeMaterials Science ForumMaterials Science Forum Vols. 556-557Time Dependent Trapping and...

Time Dependent Trapping and Generation-Recombination of Interface Charges: Modeling and Characterization for 4H-SiC MOSFETs

Abstract:

SiC MOSFETs have very large interface trap densities which degrade device performance. The effect of traps on inversion layer mobility and inversion charge concentration has been studied, and mobility models suitable for inclusion in Drift-Diffusion simulators have been developed for steady state operation of SiC MOSFET devices. Here, we attempt to model the transient behavior of SiC MOSFETs, and at the same time, extract the time constants for the filling and emptying of interface traps. As compared to the inversion layer, interface traps in SiC MOSFETs are slow in reacting to change in gate bias. So, at the positive edge of a gate pulse, we see a large current in the MOSFET, which then decays slowly to the steady state value as the interface traps fill up. We have developed a generation/recombination model for minority carriers in a SiC MOSFET based on the Shockley-Read-Hall recombination model for electrons and holes. In our model, the generation/recombination takes place between minority carriers in the inversion layer, and the traps at the SiC-SiO2 interface. Comparing our simulated current vs. time curves to experiment, we have been able to extract time constants for the filling and emptying of traps at the SiC-SiO2 interface.