Threshold Voltage Degradation for n-Channel 4H-SiC Power MOSFETs

Hall Factor Calculation for the Characterization of Transport Properties in n-channel 4H-SiC MOSFETs

For the characterization of n-channel 4H-SiC MOSFETs, current-voltage and Hall-effect measurements were carried out at room temperature. To interpret the Hall-effect measurements, the Hall factor for the electron transport in the channel of SiC MOSFETs was evaluated, for the first time. The method of the Hall factor calculation is based on the interdependence with mobility components via the re...

Threshold-voltage bias-temperature instability in commercially-available SiC MOSFETs

Verification of Near-Interface Traps Models by Electrical Measurements on 4H-SiC n-channel MOSFETs

4H-SiC n-channel lateral MOSFETs were manufactured and characterized electrically by current-voltage measurements and by numerical simulation. To describe the observed electrical characteristics of the SiC MOSFETs, Near-Interface Traps (NIT) and mobility degradation models were included in the simulation. The main finding of the simulation is that two models for the NIT states in the upper part...

Threshold voltage instabilities of present SiC-power MOSFETs under positive bias temperature stress

We study the threshold voltage (Vth) instability of commercially available silicon carbide (SiC) power MOSFETs or prototypes from four different manufacturers under positive bias temperature stress (PBTS). A positive bias near Vth causes a threshold voltage shift of 0.7 mV per decade in time per nanometer oxide thickness in the temperature range between -50°C and 150°C. Recovery at +5 V after a...

Correlation of Interface Characteristics to Electron Mobility in Channel- implanted 4H-SiC MOSFETs

To study mobility limiting mechanisms in (0001) 4H-SiC, lateral n-channel MOSFETs in p-implanted wells on n-type epitaxial layers were manufactured and additionally selectively shallow implanted with different nitrogen (N) doses in the channel region. The mobility was found to be limited by Columbic scattering at low electric fields. Further surface roughness scattering was considered as a poss...