An Analog Circuit for Accurate OCVD Measurements
An electronic circuit for making accurate open-circuit voltage decay measurements is presented. The circuit overcomes the main limitations that occur in the standard method when used for carrier lifetime characterization because it realizes the ldquoopen-circuit conditionsrdquo of the device under test with an impedance higher than 100 MOmega and reduces the noise that is inherent in the differential operation of the method.
Analysis and modelling of the electric field in the Gate oxide of 4H-SiC DMOSFET
For the first time, we report an analytical model of the electric field in the gate oxide of power DMOSFETs. The model describes the dependency of EOX on doping concentrations and thicknesses of the drift-region as well as on the JFET-region geometry when reverse bias is applied to the device. There are not fitting parameters in the equations so that the model can be used as an a priori tool of analysis for reverse behaviour. Comparisons with numerical simulations are reported in order to show the goodness of the model results.
Silicon epitaxial layer recombination and generation lifetime characterization
We have made recombination and generation lifetime measurements on silicon p-epitaxial layers on p/sup +/ and on p-substrates. The recombination lifetimes are dominated by surface/interface recombination for layers only a few microns thick. By coupling measurements of p/p with those of p/p/sup +/ samples, it is possible to extract the epi-layer lifetime. For p/p/sup +/ samples, recombination lifetimes are poorly suited to characterize epi-layers. Generation lifetime measurements are eminently suitable for epi-layer characterization, since carrier generation occurs in the space-charge region confined to the epitaxial layer, and when coupled with corona charge/Kelvin probe, allow contact-less measurements.