Homogeneously damaged surface layers of a thickness of 400 nm were generated in x-cut LiNbO 3 single crystals using multipleenergy Ar + -irradiation to study the etching behavior in aqueous HF solutions. Rutherford backscattering/channeling analysis was applied to investigate the damage formation. Different acid temperatures and concentrations were used, showing that the etching rate can be increased by increasing the temperature from 24 to 55°C maintaining the high contrast of the technique. The dissociation of HF in aqueous solution is discussed, and reaction kinetics well established for the HF etching of SiO 2 are then applied to obtain information on the etching mechanism. Therefore, the concentration dependence of the etching rate is analyzed and it is found that the etching process can be described as an attack of either HF or HF 2 − , which is catalytically supported by the presence of H + ions.