Growth and comparison of high-quality MW-PECVD grown B doped diamond layers on {118}, {115} and {113} single crystal diamond substrates

The use of {113} oriented single crystal diamond substrates has been reported for CVD growth of high-quality p-type layers with increased doping efficiency, compared to the {100} orientation, and excellent electrical properties. In this work we expand the range of crystal orientations to include the {118} and {115} planes and study the effect of B doping level in the gas phase with B/C ratios from 250 up to 2000 ppm. We demonstrate the growth of high-quality B doped SCD layers, with low RMS roughness (<2 nm) and high surface chemical purity (99% C with >1% B) for all orientations. Boron incorporation is shown to be dependent not only on the B/C in the gas phase, but also on the crystallographic orientation, with orientations with a higher density of {100}/{111} steps and risers exhibiting higher B incorporation into the solid from the gas phase (4 × 10 19 cm −3 up to 1 × 10 21 cm −3 ). Finally, using electro-chemical techniques, we confirm, for the first-time, high-quality electrodes on such orientations. In this work we report, for the first time, MW PECVD of high-quality boron doped diamond layers on vicinal {118} and {115} single crystal substrates, which are confirmed, via electro- chemical characterisation, to be excellent electrodes. • Growth of high-quality single crystal boron doped diamond on vicinal orientations from {118} to {115} to {113} • B incorporation consistent with {100}/{111} step density • First electro-chemical demonstration of use of such orientations as high-quality electrodes