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A practical parameter extraction procedure for a power silicon carbide (SiC) junction field-effect transistor (JFET) is presented. The carrier mobility and carrier concentration are very important parameters, strongly affecting the device current capability and dynamic characteristics for a given design. When modeling JFETs, the values of these parameters are usually based on assumptions and given by a vendor in a range. As a result, model accuracy is compromised. In this paper, a step-by-step parameter extraction procedure is described that includes the extraction of mobility and carrier concentration in the channel and drift regions based on knowledge of device geometrical parameters. For the first time, carrier mobilities in the channel and drift regions of a power JFET are extracted individually. It is found that channel and drift region mobilities can be very different for a given device since they are strongly dependent on the fabrication process. The separate extraction of these two mobilities can also improve model accuracy in the case of imperfect knowledge of the device geometry. The developed procedure includes the extraction of empirical parameters describing the temperature dependence of mobilities in the channel and drift regions. A simple static I– V characterization and C–V measurements are the only measurements required for the parameter extraction. In this paper, the procedure is experimentally validated for both normally off (enhancement mode) and normally on (depletion mode) JFETs. [ABSTRACT FROM AUTHOR]

A novel SiC junction field-effect transistor (JFET) model that uses a unified description of linear and saturated conduction modes is proposed. Advantages of the proposed model are improved robustness and convergence, inclusion of field-dependent mobility effects, and more physical description of the current saturation phenomenon. The model is validated against a normally off JFET sample over a wide temperature range. Finite-element simulations are used to demonstrate the physics-based nature of the proposed model. [ABSTRACT FROM AUTHOR]

In this paper, a physical model for a SiC Junction Field Effect Transistor (JFET) is presented. The novel feature of the model is that the mobility dependence on both temperature and electric field is taken into account. This is particularly important for high-current power devices where the maximum conduction current is limited by drift velocity saturation in the channel. The model equations are described in detail, emphasizing the differences introduced by the field-dependent mobility model. The model is then implemented in Pspice. Both static and dynamic simulation results are given. The results are validated with experimental results under static conditions and under resistive and inductive switching conditions. [ABSTRACT FROM AUTHOR]