Interface Trap Density and Mobility Characterization of Silicon Carbide MOSFET Inversion Layers

Vinayak Tilak; Kevin Matocha; Greg Dunne

doi:10.4028/www.scientific.net/MSF.615-617.801

Paper Titles

Comparison of 4H-SiC MOSFETs on (0001), (000-1) and (11-20) Oriented Substrates
p.785

High Channel Mobility in P-Channel MOSFETs Fabricated on 4H-SiC (0001) and Non-Basal Faces
p.789

Ab Initio Calculations of SiO₂/SiC Interfaces and High Channel Mobility MOSFET with (11-20) Face
p.793

Quasi-Charge-Sheet Model for Inversion Layer Mobility in 4H-SiC MOSFETs
p.797

Interface Trap Density and Mobility Characterization of Silicon Carbide MOSFET Inversion Layers
p.801

Investigation of On and Off State Characteristics of 4H-SiC DMOSFETs
p.805

Implications of Threshold-Voltage Instability on SiC DMOSFET Operation
p.809

Channel Hot-Carrier Effect of 4H-SiC MOSFET
p.813

Low Frequency Noise in 4H-SiC MOSFETs
p.817

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Interface Trap Density and Mobility Characterization of Silicon Carbide MOSFET Inversion Layers

Abstract:

Silicon Carbide (SiC) based metal oxide semiconductor field effect transistors (MOSFETs) were fabricated and characterized using gated hall measurements with different p-type substrate doping concentration (7.2X1016cm-3 and 2X1017 cm-3). An interface trap state density of 5X1013 cm-2eV-1 was observed nearly 0.1 eV above the conduction band edge leading to the conclusion that these states are present in the silicon dioxide rather than the interface. The Hall mobility of the MOSFETs decreased from 26.5 to 20 cm2/Vs as the doping was increased from 7.2X1016 to 2X1017cm-3. The decrease in mobility is primarily due to an increase in the surface electric field that causes an increase in surface roughness scattering. The inversion layer mobility when plotted as a function of average surface electric field is not independent of doping concentration as is the case in silicon MOSFETs because the dominant scattering mechanism is not phonon scattering.