Lateral variation of target poisoning during reactive magnetron sputtering

The reactive gas incorporation into a Ti sputter target has been investigated using laterally resolving ion beam analysis during DC magnetron deposition of TiN in an Ar/N2 atmosphere. At sufficiently low reactive gas flow, the nitrogen incorporation exhibits a pronounced lateral variation, with a lower areal density in the target race track compared to the target centre and edge. The findings are reproduced by model calculations. In the race track, the balance of reactive gas injection and sputter erosion is shifted towards erosion. The injection of nitrogen is dominated by combined molecular adsorption and recoil implantation versus direct ion implantation.