Characterizations of metal-diamond-silicon associations for active power electronics applications

Wide band gap semiconductors are discussed as materials for photonic or electron-beam controlled switches. Chemical vapour deposited (CVD) diamond has recently become the subject of intense research activity mainly due to its unique combination of thermal, mechanical and optoelectronical properties. The very high thermal conductivity, added to a high working temperature and a high dielectric strength, make CVD diamond as a promising candidate material, for high voltage electronics applications. Its semi conducting properties, such as wide band gap and high electron and hole mobilities are also noteworthy. The nature of CVD diamond is the most prominent obstacle against fabrication of any kind of electronic devices. This paper presents different grades of CVD diamond substrates and the comparison between them, especially between the natural Ha and other kind of CVD diamond. Dielectric strength investigation and surface conductivity with or without chemical treatment are presented, then the influence of the metal to diamond interface on the electronic properties have been investigated. Interdigitated planar contacts and plane back contacts have been photolithographically deposited on each sample, using different layered metals. The I(V) measurement allows to determine the optimal metallization for electronic applications. Finally, the authors investigate the response of metal-diamond-silicon components under UV illumination.