Abstract:
The influence of the addition of nitrogen on the phosphorus incorporation
into and the growth rate of epitaxial diamond films grown by hot filament
chemical vapor deposition, using a solid compound (NH4H2PO4)
as a doping source, was investigated. Experiments show that the introduction
of nitrogen gas into the system increases both the segregation of phosphorus
in the epitaxial diamond and the film growth rate. The enhancement of phosphorus
incorporation was attributed to the local lattice dilatation caused by
a significant level of nitrogen dopant, while the increase of growth rate
was explained by a model for defect-induced stabilization of diamond. From
the secondary ion mass spectrometry analysis, it was found that the effective
incorporation efficiency of nitrogen in diamond is about 9 × 10
– 4. For phosphorus it can reach a value as high as approximately
1 × 10 – 3 when a large amount of nitrogen is introduced
simultaneously to the system.