Power devices-past present and future

To those working in the field the subject of power devices has always presented a fascinating combination of physics, electronics and engineering. Reviewing the progress of the devices has proved to be an interesting study of how the combined effects of market forces, engineering needs and the persistence of research workers have been used to develop the wide range of devices available today. The essential problem faced by the power device designer is to create a switch between the power supply system and the load. As with all switches the key properties needed are the lowest on resistance, coupled with the highest voltage on the off state. The control should be simple and the transitions between the on and off states should be as rapid and loss free as possible. Within the semiconductor, these demands represent a series of conflicting requirements. The development of the device is an illustration of how new materials, knowledge and skill can deal with these