Study of the oxide trapping phenomena and their impact on the threshold voltage of lateral 4H-SiC MOSFETs

Silicon Carbide Metal-Oxide-Semiconductor is an attractive material for power electronic applications given its wide band-gap and superior physical and electrical properties than Silicon. Electric vehicles, power supplies, train traction are just a few of the potential utilization of this technology that will allow significant energy savings, included enviromental pollution. End-system designers have established that SiC power semiconductors enable solutions that are more efficient, smaller, and cost-effective than silicon (Si). SiC components are significantly more reliable and deliver superlative performance in handling grid-scale voltages. Hardware designers in the renewable energy sector such as solar or energy storage have capitalized on silicon carbide because of the results. Potentially speaking, SiC enables high-frequency switching without loss of efficiency; in simple terms, it means smaller circuit magnetic and flatter on-resistance over temperature, which leads to lower conduction loss at true operating conditions. Whether it is about boosting power from the PV panel or inverting power back to the grid, SiC is a clear choice, as it enables the design by increasing power density, reducing the size and weight of the system, and balancing system cost. However, SiC MOSFET present an unsatisfactory mobility, due to a tangled and disordered interface between the semiconductor and the dielectric. Albeit the Silicon dioxide is its native oxide, researchers and companies are struggling to find the best oxidation which will lead to a lower density of interface states.The purpose of this work is to analyse and characterize the interface states between Silicon oxide and Silicon Carbide. Unlike many other papers in literature, this study focuses on the stability of the threshold voltage at room and cryogenic temperatures, needed to discover the world of very fast traps and how they affect the device under an application point of view