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

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...

Characterization of Transient Gate Oxide Trapping in SiC MOSFETs Using Fast I–V Techniques

Threshold voltage and drain current instabilities in state-of-the-art 4H-SiC MOSFETs with thermal as-grown SiO2 and NO-annealed gate oxides have been studied using fast I–V measurements. These measurements reveal the full extent of the instability underestimated by dc measurements. Furthermore, fast measurements allow the separation of negative and positive bias stress effects. Postoxidation an...

Efficient Characterization of Threshold Voltage Instabilities in SiC nMOSFETs Using the Concept of Capture-Emission-Time Maps

We utilize the recently suggested capture-emission-time (CET) maps [1] for the first time for SiC technologies. CET maps are a very powerful characterization technique which allow the elegant and comprehensive analysis of oxide/interface traps at or near the semiconductor-dielectric interface and were originally developed to characterize degradation of Si based MOSFETs. For asprocessed SiC MOSF...

Thermal instability effects in SiC Power MOSFETs

Silicon carbide (SiC) power MOSFETs are characterised by potentially thermally unstable behaviour over a broad range of bias conditions. In the past, such behaviour has been shown for silicon (Si) MOSFETs to be related to a reduction of Safe Operating Area at higher drain–source bias voltages. For SiC MOSFETs no characterisation exists yet. This paper presents a thorough experimental investigat...

Positive bias temperature instability of SiC-MOSFETs induced by gate-switching operation