Reduction of dislocation densities in single crystal CVD diamond by using self-assembled metallic masks
Résumé
The development of diamond-based electronic devices designed to operate at high power is strongly hampered by the lack of low dislocation single crystal material. Dislocations in Chemically Vapor Deposited (CVD) diamond are indeed generally responsible for leakage current, seriously deteriorating the performance of the devices. They can be due to defects such as polishing damage or contamination found at the substrate's surface, or they can directly originate from existing bulk defects that extend into the homoepitaxial layer. Although significant improvements have been achieved by using adapted surface treatments, dislocations found in CVD diamond grown on standard quality single crystal substrates are still typically in the range 105-106 cm- 2. In this work, we report on a new growth strategy aiming at preventing threading dislocations from propagating into CVD diamond layers. It is based on the selective masking of existing defects revealed at the surface of the substrates by Pt nanoparticles. The interaction of dislocations with such embedded particles has been assessed and critical remarks are given as to the use of this technique in order to reduce dislocation densities in synthetic diamond.
Mots clés
Chemical vapor deposition
Diamonds
Plasma etching
Single crystals
Substrates
Surface defects
Synthetic diamonds
Diamond growth
Diamond-based electronic devices
Extended defect
Interaction of dislocations
Single crystal CVD diamond
Single crystal substrates
Single-crystal materials
Threading dislocation
Dislocations (crystals)