Diamond surfaces with (100) orientation and perfect phase purity regarding the coexistence of sp(3) and sp(2) bonding as well as near surface nitrogen implanted layers are repeatedly produced from one sample by a cycle of nitrogen implantation, etching in oxygen and wet chemical etching. Comprehensive surface studies carried out by X-ray photoelectron spectroscopy (XPS) involving a deconvolution of the C 1s peak into contributions of C sp(3), C sp(2) and C sp(3)(N) reveal the surface and near-surface phase and stoichiometry. It is demonstrated that efficient etching of nitrogen implanted diamond occurs by high temperature annealing in oxygen and a wet chemical treatment. (C) 2015 Elsevier B.V. All rights reserved.