Periodic nano ripple fabricated on diamond and its structure damage repair

Surface nanocrystallization and adjusting chemical compositions are anticipated to be effective strategies for exploring potential applications of diamond in physics, chemistry and biology. In this paper, the morphology evolution of a polycrystalline chemical vapor deposition diamond (PCD) under Ar+ ion beam bombardment was studied. Nano ripple was formed on the substrate. The characteristic sizes, including amplitude (A) and wavelength (W), of ripples could be adjusted by changing ion energy. Meanwhile, chemical compositions of the diamond surface after the bombardment were investigated by Raman spectrum and XPS. Amounts of lattice damage or defects appeared on the surface region of PCD due to a conversion of sp3 C to sp2 C during the ion bombardment. Moreover, high temperature annealing in vacuum was adopted to remove the damage layer. It was proved to be an effective means to restore diamond structure here and the ripple pattern could be still preserved after the thermal treatment. In addition, the variations of the sheet resistance of the PCD, which significantly increases as the increasing annealing time, offer a direct evidence to reveal the extent of restoration of diamond structure.