Multiple role of dislocations in the heteroepitaxial growth of diamond: A brief review (Phys. Status Solidi A 8∕2016)

Future success of diamond-based high-power electronic devices critically depends on the availability of wafer-size single crystals. For their realization, heteroepitaxy on iridium is currently the most promising approach in terms of scalability. However, in contrast to homoepitaxial deposition on carefully selected seed crystals, heteroepitaxial diamond layers generally start with a dislocation density of more than 10¹⁰ cm⁻² and its efficient reduction is the main issue for the subsequent growth of thick high-quality layers. In the Feature Article by M. Schreck et al. (pp. 2028–2035), several different aspects of dislocations in the CVD growth of diamond films are discussed. They comprise the mutual interaction among dislocations, their interaction with the growth surface, the decisive role of dislocations in the formation of growth stress and their role as sinks for dopant atoms. The results provide valuable insights for further efforts in material improvement and the control of stress during film growth. The cover image shows the reduction of dislocation density within the first 1000 ìm of growth and a 4-inch diamond/Ir/YSZ/Si(001) wafer after diamond nucleation and several micron growth. Various cuboids and discs with diameters of up to several centimeters in the background are products synthesized by this technique (www.audiatec.de).