Correlation between surface morphology and defect structure of heteroepitaxial diamond grown on off‐axis substrates

Abstract

The topographic surface features that develop during chemical vapour deposition of heteroepitaxial diamond on off‐axis Ir/YSZ/Si(001) and their implications on the incorporation and modification of 0D and 1D defects have been studied. After growth with nitrogen in the gas phase, the surface has split into alternating stripes of opposite inclination. The terrace regions are tilted towards the crystallographic [001] axis, while the risers are tilted in the opposite direction. AFM measurements on the macroscopic terraces reveal a microscopic substructure consisting of terraces and risers on a smaller length scale. Cross‐section SEM images display inclined dark and bright striations. In photoluminescence maps, the stripes ending at risers show a higher NV and SiV emission intensity thus indicating a stronger defect incorporation of colour centres. Relative growth rates on terrace and riser areas have been evaluated. In high resolution Raman measurements, the cross‐section maps display bands of high line width embedded in a background of lower line width. Conversion of these data into dislocation density maps reveals local variations by one order of magnitude. The tilt angle of the threading dislocation bundles is attributed to an interaction induced by the lateral step flow on the off‐axis growth surface.Scheme of the investigated diamond samples.