Topographical evolution of sputtered chromium nitride thin films

The modification of the morphology, with special emphasis on the topographical evolution, of chromium nitride thin films has been studied by varying the sputter power, bias voltage, temperature, total pressure and Ar/N2 ratio in an unbalanced magnetron sputtering process. Six different topography types (here designated pyramid, grain, crater, cone, ribbon and hillock) were identified. The growth conditions for each topography type are specified and summarized in a topography zone model showing the occurrence of each as function of temperature, Ar/N2 ratio, deposition rate and bias voltage. Furthermore, the relationship between the size of the topographical features and the deposition parameters was investigated and is reported in detail. The control of topographical type and feature size appears sufficient to hold promise of generating topographies designed for specific functions.