It’s a Long Way to “Superhard” Semiconductors

Abstract

Because of strong synergy with information technology, visible light imaging, and solar cell businesses, most of the devices for medium and high voltage power electronics are based on silicon in year 2009 [1]. Still we know, for more than 50 years, that “harder” semiconductors, exhibiting higher breakdown electric field, would be preferable [2]. On the way towards the development of such new materials, the road is very narrow between so many intricate scientific and technical obstacles. After 50 years of SiC technology development, a first generation of reliable Schottky rectifiers is now available [3,4], but it will take time to turn it into a profitable business. Despite of very important progress over the past 15 years, it is not yet clear whether there will ever be any reliable high voltage switching device based on SiC MOS [5-7]. Vertical JFET have recently appeared as realistic alternative solutions [9-12]. Hetero-epitaxial GaN materials on sapphire or silicon substrate may appear as competitors to SiC. Progress on the crystal growth of Diamond, Aluminum Nitride [8] and Boron Nitrides for electronics is on the way, but there is no convincing solution identified yet for the basic doping problems. Regarding the more ionic II-VI or I-VII semiconductors, very few people still believe that they can play a role inside future device structures for power electronics.