List of Figures

2.1. Site locations for C atoms in the c-axis direction.
2.2. Principal axes for cubic and hexagonal crystals.
2.3. Stacking sequences for five different SiC polytypes.
2.4. A map of micropipe defect count on a 3 inch semi-insulating 4H-SiC substrate.
2.5. Cross-section schematic representation of "off-axis " polish SiC surface used for homoepitaxial growth.
3.1. Wafer with surface perpendicular to the c-axis: current transport parallel and vertical to the c-axis.
3.2. Energy band diagram of a metal adjacent to n-type semiconductor under thermal noneqilibrium condition (a), metal-semiconductor contact in thermal equilibrium (b).
3.3. Energy band diagram of the selected metals and 4H-SiC.
3.4. First Brillouin zone of hexagonal Bravais lattice for $\alpha$ -SiC.
3.5. Temperature dependence of bandgap energy in $\alpha$ -SiC.
3.6. Temperature dependence of the effective density-of-states in $\alpha$ -SiC.
3.7. Temperature dependence of the intrinsic carrier concentration in $\alpha$ -SiC.
3.8. Bandgap narrowing in $\alpha$ -SiC as a function of doping concentration, and its effect on the intrinsic carrier concentration.
3.9. The n-type (N) and p-type (Al) mobility in $\alpha$ -SiC as a function of the doping concentration.
3.10. Drift velocity of electrons parallel to the basal plane as a function of the electric field in n-doped $\alpha$ -SiC at different temperatures.
3.11. Temperature dependence of the mobility of n-type $\alpha$ -SiC with increasing electric field.
3.12. Influence of temperature on heat capacity and thermal conductivity in $\alpha$ -SiC.
3.13. Impact ionization coefficients of electrons and holes for $\alpha$ -SiC at different electric field in the direction of the current flow.
3.14. Ionization level of the donor (N) and acceptor (Al) as a function of doping concentration in 4H-SiC for different temperatures.
3.15. Ionization level of the donor (N) and acceptor (Al) as a function of the doping concentration in 6H-SiC for different temperatures.
3.16. Resistivity of n-type SiC for incomplete ionization calculated from the doping-and temperature dependent mobility.
3.17. Resistivity of p-type SiC for incomplete ionization calculated from the doping-and temperature dependent mobility.
3.18. Ionization degree of N in $\alpha$ -SiC as a function of the doping concentration for different temperatures.
3.19. Ionization degree of N in $\alpha$ -SiC as a function of the temperature for different doping concentrations.
3.20. Influence of the temperature on the ionization degree of acceptors Al and B in 4H-SiC.
3.21. Ionization degree of acceptors Al and B in 4H-SiC at different doping concentrations.
3.22. Ionization degree of donor (N) with site-dependent activation energy in $\alpha$ -SiC at different temperatures.
3.23. Ionization degree of donor (N) with site-dependent activation energy in $\alpha$ -SiC for different doping concentrations.
4.1. Summary of the numerous electronic device applications for both semi-conducting and semi-insulating SiC material.
4.2. Avalanche breakdown voltage as a function of doping concentration, and blocking layer thickness as a function of the ideal breakdown voltage for a SiC and a Si abrupt pn junction.
4.3. (a) Abrupt p-n junction diode. (b) Electric field distribution.
4.4. Breakdown voltage of 4H- and 6H-SiC epilayer as a function of doping concentration and thickness.
4.5. Cross section of the Schottky barrier diode in SiC.
4.6. Forward voltage characteristics of SiC SBD for different metal contact, and saturation characteristics at high forward currents.
4.7. Reverse voltage characteristics of SiC SBD as a function of the barrier height, and influence of temperature on the leakage currents.
4.8. Influence of temperature on the forward voltage characteristics, and reverse voltage characteristics in Ni/4H-SiC SBD.
4.9. Cross section of high voltage PiN diode in SiC.
4.10. Forward voltage characteristics of 4H- and 6H-SiC PiN diode for different temperatures.
4.11. Reverse voltage characteristics of 4H- and 6H-SiC PiN diodes for different temperatures.
4.12. Cross section of a merged pin Schottky diode in SiC.
4.13. Forward voltage, and reverse voltage characteristics of 4H-SiC MPS diode at different temperatures.
4.14. Current density in the 4H-SiC MPS diode on forward bias operation.
4.15. Profile of the electric field in 4H-SiC MPS diode at 1000V reverse voltage operation.
4.16. Cross section of a UMOS power transistor in SiC.
4.17. On-state characteristics, and transfer characteristics of a UMOSFET at room temperature.
4.18. On-state characteristics, and transfer characteristics of a UMOSFET at 500 K.
4.19. The carrier mobility at 300K, and 500K of UMOSFET in 6H-SiC at V $_\mathrm{DS}$ =5 V and V $_\mathrm{GS}$ =10 V.
4.20. On-state, and transfer characteristics as a function of temperature.
4.21. Reverse bias characteristics of a UMOS power transistor in SiC, and the effect of temperature on the specific-on-resistance and leakage current.
4.22. Electric field profile in the trench area for a 1500 V reverse biased UMOSFET, and the peak field crowding at the trench corner in a three dimensional representation.
4.23. Cross section of DMOS power transistor in SiC.
4.24. On-state characteristics of DMOSFET at 300K for 4H- and 6H-SiC.
4.25. On-state characteristics of DMOSFET at 500K for 4H- and 6H-SiC.
4.26. Transfer characteristics of DMOSFET at 300K for 4H- and 6H-SiC.
4.27. Transfer characteristics of DMOSFET at 500K for 4H- and 6H-SiC.
4.28. Influence of temperature on the transfer characteristics of DMOSFET in 4H- and 6H-SiC.
4.29. The electrons mobility profile at 300K, and 500K for vertical DMOSFET in 4H-SiC.
4.30. Reverse voltage characteristics of 4H- and 6H-SiC in vertical DMOSFET for different temperatures.
4.31. Cross section of an accumulation-channel lateral DMOSFET on SiC sub-insulating substrate.
4.32. Effect of the accumulation layer thickness on device figure of merit, and comparison of transfer characteristics at room temperature for accumulation- and inversion-mode lateral DMOSFET.
4.33. Forward biased characteristics at room temperature in 6H-SiC accumulation- and inversion-mode lateral DMOSFET.
4.34. Mobility close to the surface in the gate region, and reverse biased characteristics in 6H-SiC accumulation- and inversion-mode lateral DMOSFET.
4.35. Effect of the accumulation layer thickness on the electric field, and the electric field profile at the maximum blocking voltage in 6H-SiC accumulation-mode lateral DMOSFET.
4.36. Cross section of a MESFET in 4H-SiC.
4.37. IV characteristics, and transfer characteristics of 4H-SiC MESFET.
4.38. Current density and reverse bias characteristics in a 4H-SiC MESFET.
4.39. Small-signal equivalent circuit, and comparison of measured and simulated S-parameters of 4H-SiC MESFET.
4.40. Small signal current and power gain for 4H-SiC MESFET.
C.1. Cross section of the channel region of a MESFET, and drain voltage variation along the channel.

T. Ayalew: SiC Semiconductor Devices Technology, Modeling, and Simulation


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