Silicon–carbide junction field effect transistor built-in diode: an experimentally verified electrical model

Abstract

Wide band-gap semiconductor devices like silicon-carbide junction field effect transistor (SiC JFET) are being applied in several industrial applications. Converters using these advanced devices have been introduced. SiC JFETs from SiCED/Infineon enable design of diodeless inverters. This is a positive argument regarding reliability issues for a harsh environment. From a design point of view, primary circuit models of SiC JFET have already been published but the internal diode has not been addressed so far. There is thus an interest for an accurate model of the SiC JFET built-in diode. In this study, this internal diode is demonstrated to be a power PiN diode. A novel analytical state-space model of this diode is proposed and the design parameters are identified. It is important to note, that these parameters are crucial for the device behaviour, modelling and fabrication procedure. The proposed model and associated parameters are validated with built-in diodes of several SiC JFETs. The validity domains are discussed.