Next generation advanced power devices show remarkable progress in wide band-gap power devices such as silicon carbide and gallium nitride devices, as well as novel silicon devices called as super junction FETs and so on. The future direction of power electronics applications is surveyed in terms of output power density as an index of future power electronics development, instead of the power conversion efficiency, taking the device progress in sight. Over the last 30 years, the output power density of power electronics apparatuses has increased by a factor of two figures. New markets, such as a power supply for future generation CPU, a compact unit inverter and a electric vehicle-driving inverter unit, are expected to grow rapidly from 2010 to 2015 with the advance in the out power density of power converter. The possibility of power electronics innovation with progress in the output power density will be discussed in conjunction with development of next generation advanced power devices and related technologies.

Resistive field plates achieve high breakdown voltage when merged with an ordinary metal field plate. The optimum design of the structure was studied by a two dimensional device model and experiments. It was found that a properly combined structure realizes not only a higher breakdown voltage for shallow junctions but also a higher area efficiency, compared with conventional guard ring technologies.