Comparison of Plasma Effect on Dewetting Kinetics of Sn Films Between Grounded and Floating Substrates

Abstract

When metal thin films deposited typically by sputtering is heated to sufficiently high temperature, thin films tend to disintegrate into individual isolated spherical particles, whose phenomenon is called thermal dewetting. If such metal films are exposed to plasma, however, the dewetting kinetics is enhanced dramatically. One possibility for enhanced dewetting kinetics is the ion bombardment on the film surface from plasma. The other possibility is the excess charge buildup on the film surface provided from plasma. If enhanced dewetting kinetics is due to charge buildup, it can provide an evidence for charge-enhanced kinetics, which has been suggested as a hypothesis to explain the evolution of void-free dense films in non-classical crystallization where the building block is charged nanoparticles. To clarify which is responsible for plasma enhanced dewetting, the dewetting behavior of 100 nm thick Sn films on silicon substrates with native oxide surface was compared between floating and grounded films in the inductively-coupled plasma environment. The dewetting kinetics on the floating film was much higher than that on the grounded film. These results indicate that the charge buildup is responsible for the plasma enhanced dewetting kinetics.