Abstract : A method for obtaining a smooth, single crystal diamond surface is presented, whereby a sacrificial defective layer is created by implantation of a regular (4 nm roughness) Ib diamond plate. This was then graphitized by annealing before being selectively etched. We have used O(+) at 240 keV, the main process variables being the ion fluence (ranging from 3 x 10(15) to 3 x 10(17)cm(-2)) and the final etching process (wet etch, H(2) plasma, and annealing in air). The substrates were characterized by atomic force microscopy, optical profilometry and white beam X-ray topography. The influence of the various process parameters on the resulting lift-off efficiency and final surface roughness is discussed. An O(+) fluence of 2 x 10(17)cm(-2) was found to result in sub-nanometer roughness over tens of mu m(2).