Surface morphology analysis of natural single crystal diamond chips bombarded with Ar+ ion beam

We have studied the surface morphology of natural single crystal diamond chips machined by 0.5–3.0 keV Ar+ ion beam irradiation at ion incidence angles of 0°, 30°, 45°, 60°, and 80° with ion doses from 3.4 × 1018 ions/cm2 to 6.8 × 1018 ions/cm2. The surface of diamond chips machined with 0.5 and 1.0 keV Ar+ ion beam, at angles of ion incidence from 0° to 45° can be made smooth. Results show that the machined surface at ion dose of 6.8 × 1018 ions/cm2 and beam energy of 0.5 and 1.0 keV become ultra-smooth (surface roughness SR = 0.1 nm rms) compared with unprocessed surface (SR = 0.15–2.1 nm rms). Results also confirm the ripple formation on diamond surface at ion incidence angles of 60°–80° by 0.5–3.0 keV Ar+ ion beam. Therefore, the technique of smoothing by choosing ion beam irradiation parameter can be applicable to nano-finishing of diamond tools without ripple formation. This technique can also be applicable in mass production if the diamond surface is mechanically pre-finished.