Incorporation of phosphorus donors in (110)-textured polycrystalline diamond

The incorporation efficiency of phosphorus was studied as a function of the surface orientation of grains in (110)-textured polycrystalline chemical vapor deposited diamond. Cathodoluminescence mapping of such films exhibits large local differences in relative intensities stemming from P-bound and free excitons. Combined with electron backscattering diffraction mapping, these data allow assessing of the donor concentration as a function of the grain orientation. While [P] can vary between 1015 and >1018 cm−3 within one film, misorientation angles of more than 10° with respect to the exact [110] axis assure an enhanced incorporation of P with concentrations surpassing 5×1017 cm−3. The role of the surface morphology in the observation of these large incorporation differences is explained.