Stress and thermal stress evolution in Mo and Ru thin films

In this work, the microstructural and stress evolution of Mo and Ru films is studied at relevant temperatures for interconnect processing. Wafer bow measurements, transmission electron microscopy (TEM), in-situ XRD (IS-XRD), and microelectromechanical systems (MEMS) were used to determine stress and thermal stress evolution for 10 to 30 nm thick films. We show that Mo and Ru present a complex evolution of the stress evolution during thermal cycling that can be linked to the creation and diffusion of point defects.