Dissertation
Modeling of Defect Related Reliability Phenomena
in SiC Power-MOSFETs
zur Erlangung des akademischen Grades
Doktor der technischen Wissenschaften
eingereicht and der
Technische Universität Wien
Fakultät für Elektrotechnik und Informationstechnik
von
Dipl.-Ing. Christian Schleich
Matr. Nr. 1325958
geboren am 30. Mai 1987 in Ried i.I., Österreich
unter Betreuung von
Univ.Prof. Dipl.-Ing. Dr.techn. Tibor Grasser
und
Assistant Prof. Dipl.-Ing. Dr.techn. Michael Waltl
Wien, August 2022
Contents
1.1 MOSFETs in Power Conversion Applications
1.1.2 From MOSFETs to SiC Power Switches
1.1.3 Silicon Carbide Material Properties
1.1.4 Fabrication and Properties of SiC MOSFETs
1.2.1 Bias Temperature Instabilities
1.2.2 Gate Leakage Currents and Oxide Breakdown
1.3 State of the Art, Motivation and Outline
2 SiC MOSFET Reliability Characterization
2.1 Electrical Characterization Methods
2.1.1 Transfer Characteristics
2.1.2 Capacitance Voltage Measurements
2.1.3 Measure-Stress-Measure Schemes
2.1.4 Single Charge Transfer Measurements
2.2 Peculiarities of SiC Metal Oxide Semiconductor Field-Effect Transistor (MOSFET) Characterization
2.4 Magnetic Resonance Methods
3 Defects in SiC Field Effect Transistors
3.1 Defects in Bulk Silicon Dioxide
3.2 Defects at the Silicon Carbide / Silicon Dioxide Interface
4 Modeling of Charge Transfer Reactions
4.1 From State Diagrams to the Master Equation
4.2 The Shockley-Read-Hall Model
4.3 Non-Radiative Multi-Phonon Theory
4.4 Two-State NMP Model for Trap-Trap Interaction
4.4.1 Parameter Transformation
4.5 Efficient Framework for MOS Gate Leakage Currents
4.6 Compact Physics Framework (Comphy)
4.6.1 Electrostatic Quantities
4.6.3 Gate Leakage Current Computation
4.8 Effective Single Defect Decomposition
5 Measurements, Simulations and Results
5.1 Bias Temperature Instabilities in SiC MOSFETs
5.1.2 Comparison of different DMOS Technologies
5.1.4 Temperature Activation of Electron Emission
5.1.5 Capture and Emission Time Maps
5.1.6 Reliable Prediction of th
5.2 Trap-Assisted Tunneling Currents
5.2.1 Tunnel Currents in SiC MOSCAPs