Effect of Adatom Energy on the Interfacial and Surface Morphology of Pulsed DC Sputtered Ruthenium Thin Films

ABSTRACT In the present study, we have analyzed the growth profile of ruthenium (Ru) thin films, deposited using pulsed direct current (DC) magnetron sputtering technique, by varying the sputtering voltages in the range of 150–420 V. The grazing incidence X‐ray reflectivity (GIXRR), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), and atomic force microscopy (AFM) techniques were employed to determine the interface characteristics and surface morphology. A pronounced Ru diffusion was found inside the substrate region with an increase in sputtering voltage, and the density and roughness of the interfacial layer also increased. The surface roughness was found to increase from 0.28 to 2.6 nm. Details of the growth profile as determined from the GIXRR and SIMS measurements are discussed.