Non-destructive characterization of ion-implanted diamond

Abstract A position-sensitive micro-spectrophotometer with slightly focused light in transmission mode has been employed to characterize the optical inhomogeneity of the original synthetic diamond crystal (1 0 0) surface and a modified carbon layer and its defects induced by low-energy H 2 + implantation at 100 K and room temperature. The distribution of strong absorption relative to different positions, which starts at around 470 nm down to 280 nm in the VIS-UV regions, reflects a distinctive difference of nitrogen concentration and intrinsic defects in different growth sectors. The typical morphology of the intrinsic or ion-induced defects is showed in a two-dimensional topography adjusted at the near absorption edge ( λ =430 nm). The relative optical density (OD) and band gap ( E r,opt ) are deduced via the use of the normalized transmittance and are used to interpret the energetic ion-induced defect and its evolution depending on the implanted dose and annealing temperature. It is found that the gradual change from pale to deep reddish brown color in both the reflection and refraction orientations is associated with the dosage levels injected into top submicrometer layer, but is independent of the implantation temperature. The critical dose for the conversion of the diamond structure into a disordered network and the migrating temperature for nitrogen atoms in H 2 + ion radiation-damaged diamond are found to be more than 1.3×10 17  H/cm 2 and 1200°C, respectively.