Oxygen impurities at the homoepitaxially grown diamond-substrate interface analyzed by secondary ion mass spectrometry

We have investigated impurities at the interface between homoepitaxial diamond thin layers and diamond substrates as well as the diffusion of the impurities, using secondary ion mass spectrometry (SIMS), A significant amount of oxygen has been observed at the interface. The amount of oxygen remaining at the interface between the grown layer and substrate diamond decreases with increasing deposition temperature. No oxygen is detected at the interface of samples grown above the deposition temperature of 850 degrees C. No significant change in the impurities was observed after annealing treatment under high pressure and high temperature conditions (7.7 GPa, 2350 degrees C), at which diamond is thermodynamically stable.