Detection of Very Fast Interface Traps at 4H-SiC/AlN and 4H-SiC/Al2O3 Interfaces

Arnar M. Vidarsson; Axel R. Persson; J. Tai Chen; Daniel Haasmann; Jawad Ul-Hassan; Sima Dimitrijev; Niklas Rorsman; Vanya Darakchieva; E.Ö. Sveinbjörnsson

doi:10.4028/p-8gOXKi

Paper Titles

Comparing 4H-SiC NPN Buffer Layers by Epitaxial Growth and Implantation for Neural Interface Isolation
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Modeling the Charging of Gate Oxide under High Electric Field
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Complementary Two Dimensional Carrier Profiles of 4H-SiC MOSFETs by Scanning Spreading Resistance Microscopy and Scanning Capacitance Microscopy
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Temperature Dependence of 4H-SiC Gate Oxide Breakdown and C-V Properties from Room Temperature to 500 °C
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Detection of Very Fast Interface Traps at 4H-SiC/AlN and 4H-SiC/Al₂O₃ Interfaces
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A Voltage Adjustable Diode Integrated SiC Trench MOSFET with Barrier Control Gate
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Effects of High Gate Voltage Stress on Threshold Voltage Stability in Planar and Trench SiC Power MOSFETs
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Design of Al₂O₃/LaAlO₃/SiO₂ Gate Stack on Various Channel Planes for High-Performance 4H-SiC Trench Power MOSFETs
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Channel Density Design Guidelines for the Transient Characteristics of SiC Trench Gate MOSFETs
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Detection of Very Fast Interface Traps at 4H-SiC/AlN and 4H-SiC/Al₂O₃ Interfaces

Abstract:

Modest channel carrier mobility in SiC-MOSFETs with NO annealed gate oxides has been the main factor hampering development of low power devices (300 – 650 V). A very fast interface trap, noted as NI, has been suggested to be the main culprit for poor inversion channel carrier mobility. The origin of the NI trap is unknown, but it is likely a property of the SiO₂ and it is enhanced during post nitridation. In this study we show that the NI trap is also detected in 4H-SiC/AlN and 4H-SiC/Al₂O₃ MIS-capacitors. Observations are done using conductance spectroscopy and capacitance voltage measurements at cryogenic temperatures. This strongly suggests that the NI trap is a property of the SiC surface and not the dielectric used to form the SiC/dielectric interface. Furthermore, a scanning transmission electron microscopy (STEM) was performed to confirm that there are no SiO₂ layers or islands present at the 4H-SiC/AlN and 4H-SiC/Al₂O₃ interfaces.