On the Origin of Threshold Voltage Instability under Operating Conditions of 4H-SiC n-Channel MOSFETs

Gregor Pobegen; Julietta Weisse; Martin Hauck; Heiko B. Weber; M. Krieger

doi:10.4028/www.scientific.net/MSF.858.473

Paper Titles

Importance of SiC Stacking to Interlayer States at the SiC/SiO₂ Interface
p.457

Measurement Issues Affecting Threshold-Voltage Instability Characterization of SiC MOSFETs
p.461

Mechanisms of Nitrogen Incorporation at 4H-SiC/SiO₂ Interface during Nitric Oxide Passivation – A First Principles Study
p.465

Nondestructive and Local Evaluation of SiO₂/SiC Interface Using Super-Higher-Order Scanning Nonlinear Dielectric Microscopy
p.469

On the Origin of Threshold Voltage Instability under Operating Conditions of 4H-SiC n-Channel MOSFETs
p.473

Pragmatic Approach to the Characterization of SiC/SiO₂ Interface Traps near the Conduction Band with Split C-V and Hall Measurements
p.477

Threshold Voltage Instabilities of Present SiC-Power MOSFETs under Positive Bias Temperature Stress
p.481

Failure Analysis of a SiC MOS Capacitor with a Poly-Si Gate Electrode
p.485

Ultra-Fast SiC Wafer Surface Roughness Mapping
p.489

HomeMaterials Science ForumMaterials Science Forum Vol. 858On the Origin of Threshold Voltage Instability...

On the Origin of Threshold Voltage Instability under Operating Conditions of 4H-SiC n-Channel MOSFETs

Abstract:

We report on the threshold voltage () instability under operating conditions after gate bias switches at constant drain voltage for n-MOSFETs fabricated on 4H silicon carbide (4H-SiC). This effect occurs at room temperature and close to the of the device. We show that the origin of the instability is electron trapping into SiO₂ over an energy barrier of (0.3-0.4) eV. These traps show similarities to traps previously observed in 4H-SiC MOS capacitors and labelled near interface traps (NITs). Further, the density of the traps can be reduced by one order of magnitude through post-oxidation annealing in nitric oxide atmosphere.