Evaluation of Alternative Source Connection's Impact on the Reliability of SiC MOSFET

Conventional, widely adopted common source packaged silicon-carbide Metal Oxide Semiconductor Field Effect Transistor (SiC MOSFET) has raised concern in generating more switching losses. During every switching cycle, the stray inductance induced by the source bond wire generates a voltage that opposes the MOSFET’s driving signal. This opposing voltage slows down the switching and increases the switching loss, which causes efficiency concerns. A Kelvinconnected gate-source was introduced in recent SiC MOSFET, and it eliminates the effect of parasitic components to avoid any disturbance on the driving signal. However, the Kelvin source SiC MOSFET's lifetime and reliability performance remains undiscovered. This thesis studies the effect of the alternative source connection on MOSFET reliability by comparing their performances under different degradation tests. The conventional commercial device characterization system was found extremely time-consuming and labor-cost during the study. The conventional system can solely characterize one power device each time, and it requires switching devices under test (DUTs) manually, which causes troubles in capturing high-resolution characterization data. As a result, an automatic and large-scale power device characterization system is also proposed in this thesis. The goal of the thesis can be summarized as follows: ● Identify the effect of alternative source connection on the lifetime and reliability performance of SiC MOSFET; ● Develop an automatic and large-scale power device characterization system