Differential sputter yield profiles of molybdenum due to bombardment by low energy xenon ions at normal and oblique incidence

We report differential sputter yield measurements for Xe+ ions incident on molybdenum for ion incidence angles of 0 degrees, 15 degrees, 30 degrees and 45 degrees, and ion energies of 250, 350, 500 and 750 eV. The angularly resolved profiles are obtained with a quartz crystal microbalance that is moved to a series of locations above the target. Total sputter yields found by integrating the differential sputter yields are in accord with the literature values. For normally incident ions the profiles are under-cosine, while for obliquely incident ions the profiles show azimuthal variation with pronounced forward sputtering lobes. We discuss the use of published expressions from Zhang and Zhang ( 2004 Radiat. Eff. Defects Solids 159 301 - 7) for describing the measured profiles. We find that the profiles can be reasonably described with these expressions by using two free parameters: the total sputter yield (Y) and a characteristic energy (E*). We compare changes in angular sputtering profiles from lightly versus heavily sputtered targets.