High-power switching in semiconductors - What is beyond silicon thyristor?

A critical evaluation of high-power electronics switching in semiconductor materials is made from the standpoint of performance, reliability, and commercial viability. This study takes into account recent experimental results obtained from the field-reliability study of silicon power MOSFETs in high-density power supplies where residual material defects present in the space charge region of the device were found to generate local micro plasma that eventually caused power MOSFETs to fail. Based on these results and commercial progress made to date in wide bandgap semiconductor technologies, it is suggested that silicon carbide (SiC) promises to be the preferred material for high-power electronics switching from cost, performance and reliability considerations - this assessment is further strengthened by the near-term potential for developing large-area, low-cost, and defect-free SiC bulk substrates and epitaxial layers. This conclusion is also supported by the feasibility and the need for vertical, MOS-controlled, bipolar power switches in compact and efficient megaWatt-level power converters in order to make transformational changes in the 21^st century electrical transmission and distribution infrastructure.