Nanowerk July 4, 2021
To create thin films of tungsten with unprecedentedly low levels of film stress researchers in Japan have been working with scattering (HiPIMS), a sputtering technique. Using argon gas and a tungsten target, the team looked at how ions with different energies arrived at the substrate over time in unprecedented detail. Instead of using a bias pulse set off at the same time as the HiPIMS pulse, they used their knowledge of when different ions arrived and introduced a tiny delay, 60 microseconds, to precisely select for the arrival of high energy metal ions. They found that this minimized the amount of gas ending up in the film and efficiently delivered high levels of kinetic energy. The result was a dense crystalline film with large grains and low film stress. By making the bias stronger, the films became more and more stress-free. An efficient pathway to stress-free films will have a significant impact on metallization processes and the manufacture of next-generation circuitry. The technology may be applied to other metals and promises big gains for the electronics industry…read more. Open Access TECHNICAL ARTICLEÂ
Time evolution of the energy-integrated ion flux intensity of W+, W2+, and Ar+ recorded at the substrate position d = 100 mm during a HiPIMS discharge of W in 1 Pa Ar… Credit: Journal of Applied Physics 129, 155305 (2021)Â